1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.7
6 * New command line options
9 This is an alias for the --data-directory option.
11 * GDB supports printing and modifying of variable length automatic arrays
12 as specified in ISO C99.
14 * The ARM simulator now supports instruction level tracing
15 with or without disassembly.
19 GDB now has support for scripting using Guile. Whether this is
20 available is determined at configure time.
21 Guile version 2.0 or greater is required.
22 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
24 * New commands (for set/show, see "New options" below)
28 Invoke CODE by passing it to the Guile interpreter.
32 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
34 info auto-load guile-scripts [regexp]
35 Print the list of automatically loaded Guile scripts.
37 * The source command is now capable of sourcing Guile scripts.
38 This feature is dependent on the debugger being built with Guile support.
42 set print symbol-loading (off|brief|full)
43 show print symbol-loading
44 Control whether to print informational messages when loading symbol
45 information for a file. The default is "full", but when debugging
46 programs with large numbers of shared libraries the amount of output
49 set guile print-stack (none|message|full)
50 show guile print-stack
51 Show a stack trace when an error is encountered in a Guile script.
53 set auto-load guile-scripts (on|off)
54 show auto-load guile-scripts
55 Control auto-loading of Guile script files.
57 maint ada set ignore-descriptive-types (on|off)
58 maint ada show ignore-descriptive-types
59 Control whether the debugger should ignore descriptive types in Ada
60 programs. The default is not to ignore the descriptive types. See
61 the user manual for more details on descriptive types and the intended
64 * New features in the GDB remote stub, GDBserver
66 ** New option --debug-format=option1[,option2,...] allows one to add
67 additional text to each output. At present only timestamps
68 are supported: --debug-format=timestamps.
69 Timestamps can also be turned on with the
70 "monitor set debug-format timestamps" command from GDB.
72 * The 'record instruction-history' command now starts counting instructions
73 at one. This also affects the instruction ranges reported by the
74 'record function-call-history' command when given the /i modifier.
76 * The command 'record function-call-history' supports a new modifier '/c' to
77 indent the function names based on their call stack depth.
78 The fields for the '/i' and '/l' modifier have been reordered.
79 The source line range is now prefixed with 'at'.
80 The instruction range is now prefixed with 'inst'.
81 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
82 "record instruction-history" and "list" commands.
84 * The ranges given as arguments to the 'record function-call-history' and
85 'record instruction-history' commands are now inclusive.
87 * The btrace record target now supports the 'record goto' command.
88 For locations inside the execution trace, the back trace is computed
89 based on the information stored in the execution trace.
91 * The btrace record target supports limited reverse execution and replay.
92 The target does not record data and therefore does not allow reading
95 * The "catch syscall" command now works on s390*-linux* targets.
97 * The "compare-sections" command is no longer specific to target
98 remote. It now works with all targets.
102 qXfer:btrace:read's annex
103 The qXfer:btrace:read packet supports a new annex 'delta' to read
104 branch trace incrementally.
108 ** Valid Python operations on gdb.Value objects representing
109 structs/classes invoke the corresponding overloaded operators if
113 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
115 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
116 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
117 its alias "share", instead.
119 *** Changes in GDB 7.7
121 * Improved support for process record-replay and reverse debugging on
122 arm*-linux* targets. Support for thumb32 and syscall instruction
123 recording has been added.
125 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
127 * GDB now supports Fission DWP file format version 2.
128 http://gcc.gnu.org/wiki/DebugFission
130 * New convenience function "$_isvoid", to check whether an expression
131 is void. A void expression is an expression where the type of the
132 result is "void". For example, some convenience variables may be
133 "void" when evaluated (e.g., "$_exitcode" before the execution of
134 the program being debugged; or an undefined convenience variable).
135 Another example, when calling a function whose return type is
138 * The "maintenance print objfiles" command now takes an optional regexp.
140 * The "catch syscall" command now works on arm*-linux* targets.
142 * GDB now consistently shows "<not saved>" when printing values of
143 registers the debug info indicates have not been saved in the frame
144 and there's nowhere to retrieve them from
145 (callee-saved/call-clobbered registers):
150 (gdb) info registers rax
153 Before, the former would print "<optimized out>", and the latter
154 "*value not available*".
156 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
161 ** Frame filters and frame decorators have been added.
162 ** Temporary breakpoints are now supported.
163 ** Line tables representation has been added.
164 ** New attribute 'parent_type' for gdb.Field objects.
165 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
166 ** New attribute 'name' for gdb.Type objects.
170 Nios II ELF nios2*-*-elf
171 Nios II GNU/Linux nios2*-*-linux
172 Texas Instruments MSP430 msp430*-*-elf
174 * Removed native configurations
176 Support for these a.out NetBSD and OpenBSD obsolete configurations has
177 been removed. ELF variants of these configurations are kept supported.
179 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
180 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
181 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
182 i[34567]86-*-openbsd3.[0-3]
183 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
184 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
185 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
189 Like "catch throw", but catches a re-thrown exception.
191 Renamed from old "maint check-symtabs".
193 Perform consistency checks on symtabs.
195 Expand symtabs matching an optional regexp.
198 Display the details of GDB configure-time options.
200 maint set|show per-command
201 maint set|show per-command space
202 maint set|show per-command time
203 maint set|show per-command symtab
204 Enable display of per-command gdb resource usage.
206 remove-symbol-file FILENAME
207 remove-symbol-file -a ADDRESS
208 Remove a symbol file added via add-symbol-file. The file to remove
209 can be identified by its filename or by an address that lies within
210 the boundaries of this symbol file in memory.
213 info exceptions REGEXP
214 Display the list of Ada exceptions defined in the program being
215 debugged. If provided, only the exceptions whose names match REGEXP
220 set debug symfile off|on
222 Control display of debugging info regarding reading symbol files and
223 symbol tables within those files
225 set print raw frame-arguments
226 show print raw frame-arguments
227 Set/show whether to print frame arguments in raw mode,
228 disregarding any defined pretty-printers.
230 set remote trace-status-packet
231 show remote trace-status-packet
232 Set/show the use of remote protocol qTStatus packet.
236 Control display of debugging messages related to Nios II targets.
240 Control whether target-assisted range stepping is enabled.
242 set startup-with-shell
243 show startup-with-shell
244 Specifies whether Unix child processes are started via a shell or
249 Use the target memory cache for accesses to the code segment. This
250 improves performance of remote debugging (particularly disassembly).
252 * You can now use a literal value 'unlimited' for options that
253 interpret 0 or -1 as meaning "unlimited". E.g., "set
254 trace-buffer-size unlimited" is now an alias for "set
255 trace-buffer-size -1" and "set height unlimited" is now an alias for
258 * The "set debug symtab-create" debugging option of GDB has been changed to
259 accept a verbosity level. 0 means "off", 1 provides basic debugging
260 output, and values of 2 or greater provides more verbose output.
262 * New command-line options
264 Display the details of GDB configure-time options.
266 * The command 'tsave' can now support new option '-ctf' to save trace
267 buffer in Common Trace Format.
269 * Newly installed $prefix/bin/gcore acts as a shell interface for the
272 * GDB now implements the the C++ 'typeid' operator.
274 * The new convenience variable $_exception holds the exception being
275 thrown or caught at an exception-related catchpoint.
277 * The exception-related catchpoints, like "catch throw", now accept a
278 regular expression which can be used to filter exceptions by type.
280 * The new convenience variable $_exitsignal is automatically set to
281 the terminating signal number when the program being debugged dies
282 due to an uncaught signal.
286 ** All MI commands now accept an optional "--language" option.
287 Support for this feature can be verified by using the "-list-features"
288 command, which should contain "language-option".
290 ** The new command -info-gdb-mi-command allows the user to determine
291 whether a GDB/MI command is supported or not.
293 ** The "^error" result record returned when trying to execute an undefined
294 GDB/MI command now provides a variable named "code" whose content is the
295 "undefined-command" error code. Support for this feature can be verified
296 by using the "-list-features" command, which should contain
297 "undefined-command-error-code".
299 ** The -trace-save MI command can optionally save trace buffer in Common
302 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
304 ** The command -data-list-register-values now accepts an optional
305 "--skip-unavailable" option. When used, only the available registers
308 ** The new command -trace-frame-collected dumps collected variables,
309 computed expressions, tvars, memory and registers in a traceframe.
311 ** The commands -stack-list-locals, -stack-list-arguments and
312 -stack-list-variables now accept an option "--skip-unavailable".
313 When used, only the available locals or arguments are displayed.
315 ** The -exec-run command now accepts an optional "--start" option.
316 When used, the command follows the same semantics as the "start"
317 command, stopping the program's execution at the start of its
318 main subprogram. Support for this feature can be verified using
319 the "-list-features" command, which should contain
320 "exec-run-start-option".
322 ** The new commands -catch-assert and -catch-exceptions insert
323 catchpoints stopping the program when Ada exceptions are raised.
325 ** The new command -info-ada-exceptions provides the equivalent of
326 the new "info exceptions" command.
328 * New system-wide configuration scripts
329 A GDB installation now provides scripts suitable for use as system-wide
330 configuration scripts for the following systems:
334 * GDB now supports target-assigned range stepping with remote targets.
335 This improves the performance of stepping source lines by reducing
336 the number of control packets from/to GDB. See "New remote packets"
339 * GDB now understands the element 'tvar' in the XML traceframe info.
340 It has the id of the collected trace state variables.
342 * On S/390 targets that provide the transactional-execution feature,
343 the program interruption transaction diagnostic block (TDB) is now
344 represented as a number of additional "registers" in GDB.
350 The vCont packet supports a new 'r' action, that tells the remote
351 stub to step through an address range itself, without GDB
352 involvemement at each single-step.
354 qXfer:libraries-svr4:read's annex
355 The previously unused annex of the qXfer:libraries-svr4:read packet
356 is now used to support passing an argument list. The remote stub
357 reports support for this argument list to GDB's qSupported query.
358 The defined arguments are "start" and "prev", used to reduce work
359 necessary for library list updating, resulting in significant
362 * New features in the GDB remote stub, GDBserver
364 ** GDBserver now supports target-assisted range stepping. Currently
365 enabled on x86/x86_64 GNU/Linux targets.
367 ** GDBserver now adds element 'tvar' in the XML in the reply to
368 'qXfer:traceframe-info:read'. It has the id of the collected
369 trace state variables.
371 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
374 * New 'z' formatter for printing and examining memory, this displays the
375 value as hexadecimal zero padded on the left to the size of the type.
377 * GDB can now use Windows x64 unwinding data.
379 * The "set remotebaud" command has been replaced by "set serial baud".
380 Similarly, "show remotebaud" has been replaced by "show serial baud".
381 The "set remotebaud" and "show remotebaud" commands are still available
382 to provide backward compatibility with older versions of GDB.
384 *** Changes in GDB 7.6
386 * Target record has been renamed to record-full.
387 Record/replay is now enabled with the "record full" command.
388 This also affects settings that are associated with full record/replay
389 that have been moved from "set/show record" to "set/show record full":
391 set|show record full insn-number-max
392 set|show record full stop-at-limit
393 set|show record full memory-query
395 * A new record target "record-btrace" has been added. The new target
396 uses hardware support to record the control-flow of a process. It
397 does not support replaying the execution, but it implements the
398 below new commands for investigating the recorded execution log.
399 This new recording method can be enabled using:
403 The "record-btrace" target is only available on Intel Atom processors
404 and requires a Linux kernel 2.6.32 or later.
406 * Two new commands have been added for record/replay to give information
407 about the recorded execution without having to replay the execution.
408 The commands are only supported by "record btrace".
410 record instruction-history prints the execution history at
411 instruction granularity
413 record function-call-history prints the execution history at
416 * New native configurations
418 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
419 FreeBSD/powerpc powerpc*-*-freebsd
420 x86_64/Cygwin x86_64-*-cygwin*
421 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
425 ARM AArch64 aarch64*-*-elf
426 ARM AArch64 GNU/Linux aarch64*-*-linux
427 Lynx 178 PowerPC powerpc-*-lynx*178
428 x86_64/Cygwin x86_64-*-cygwin*
429 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
431 * If the configured location of system.gdbinit file (as given by the
432 --with-system-gdbinit option at configure time) is in the
433 data-directory (as specified by --with-gdb-datadir at configure
434 time) or in one of its subdirectories, then GDB will look for the
435 system-wide init file in the directory specified by the
436 --data-directory command-line option.
438 * New command line options:
440 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
441 other initialization files, unlike -nx which disables all of them.
443 * Removed command line options
445 -epoch This was used by the gdb mode in Epoch, an ancient fork of
448 * The 'ptype' and 'whatis' commands now accept an argument to control
451 * 'info proc' now works on some core files.
455 ** Vectors can be created with gdb.Type.vector.
457 ** Python's atexit.register now works in GDB.
459 ** Types can be pretty-printed via a Python API.
461 ** Python 3 is now supported (in addition to Python 2.4 or later)
463 ** New class gdb.Architecture exposes GDB's internal representation
464 of architecture in the Python API.
466 ** New method Frame.architecture returns the gdb.Architecture object
467 corresponding to the frame's architecture.
469 * New Python-based convenience functions:
471 ** $_memeq(buf1, buf2, length)
472 ** $_streq(str1, str2)
474 ** $_regex(str, regex)
476 * The 'cd' command now defaults to using '~' (the home directory) if not
479 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
480 default for GCC since November 2000.
482 * The command 'forward-search' can now be abbreviated as 'fo'.
484 * The command 'info tracepoints' can now display 'installed on target'
485 or 'not installed on target' for each non-pending location of tracepoint.
487 * New configure options
489 --enable-libmcheck/--disable-libmcheck
490 By default, development versions are built with -lmcheck on hosts
491 that support it, in order to help track memory corruption issues.
492 Release versions, on the other hand, are built without -lmcheck
493 by default. The --enable-libmcheck/--disable-libmcheck configure
494 options allow the user to override that default.
495 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
496 This configure option allows the user to build GDB with
497 libbabeltrace using which GDB can read Common Trace Format data.
499 * New commands (for set/show, see "New options" below)
502 Catch signals. This is similar to "handle", but allows commands and
503 conditions to be attached.
506 List the BFDs known to GDB.
508 python-interactive [command]
510 Start a Python interactive prompt, or evaluate the optional command
511 and print the result of expressions.
514 "py" is a new alias for "python".
516 enable type-printer [name]...
517 disable type-printer [name]...
518 Enable or disable type printers.
522 ** For the Renesas Super-H architecture, the "regs" command has been removed
523 (has been deprecated in GDB 7.5), and "info all-registers" should be used
528 set print type methods (on|off)
529 show print type methods
530 Control whether method declarations are displayed by "ptype".
531 The default is to show them.
533 set print type typedefs (on|off)
534 show print type typedefs
535 Control whether typedef definitions are displayed by "ptype".
536 The default is to show them.
538 set filename-display basename|relative|absolute
539 show filename-display
540 Control the way in which filenames is displayed.
541 The default is "relative", which preserves previous behavior.
543 set trace-buffer-size
544 show trace-buffer-size
545 Request target to change the size of trace buffer.
547 set remote trace-buffer-size-packet auto|on|off
548 show remote trace-buffer-size-packet
549 Control the use of the remote protocol `QTBuffer:size' packet.
553 Control display of debugging messages related to ARM AArch64.
556 set debug coff-pe-read
557 show debug coff-pe-read
558 Control display of debugging messages related to reading of COFF/PE
563 Control display of debugging messages related to Mach-O symbols
566 set debug notification
567 show debug notification
568 Control display of debugging info for async remote notification.
572 ** Command parameter changes are now notified using new async record
573 "=cmd-param-changed".
574 ** Trace frame changes caused by command "tfind" are now notified using
575 new async record "=traceframe-changed".
576 ** The creation, deletion and modification of trace state variables
577 are now notified using new async records "=tsv-created",
578 "=tsv-deleted" and "=tsv-modified".
579 ** The start and stop of process record are now notified using new
580 async record "=record-started" and "=record-stopped".
581 ** Memory changes are now notified using new async record
583 ** The data-disassemble command response will include a "fullname" field
584 containing the absolute file name when source has been requested.
585 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
586 command, to allow pattern filling of memory areas.
587 ** New commands "-catch-load"/"-catch-unload" added for intercepting
588 library load/unload events.
589 ** The response to breakpoint commands and breakpoint async records
590 includes an "installed" field containing a boolean state about each
591 non-pending tracepoint location is whether installed on target or not.
592 ** Output of the "-trace-status" command includes a "trace-file" field
593 containing the name of the trace file being examined. This field is
594 optional, and only present when examining a trace file.
595 ** The "fullname" field is now always present along with the "file" field,
596 even if the file cannot be found by GDB.
598 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
599 You must have the LZMA library available when configuring GDB for this
600 feature to be enabled. For more information, see:
601 http://fedoraproject.org/wiki/Features/MiniDebugInfo
606 Set the size of trace buffer. The remote stub reports support for this
607 packet to gdb's qSupported query.
610 Enable Branch Trace Store (BTS)-based branch tracing for the current
611 thread. The remote stub reports support for this packet to gdb's
615 Disable branch tracing for the current thread. The remote stub reports
616 support for this packet to gdb's qSupported query.
619 Read the traced branches for the current thread. The remote stub
620 reports support for this packet to gdb's qSupported query.
622 *** Changes in GDB 7.5
624 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
625 for more x32 ABI info.
627 * GDB now supports access to MIPS DSP registers on Linux targets.
629 * GDB now supports debugging microMIPS binaries.
631 * The "info os" command on GNU/Linux can now display information on
632 several new classes of objects managed by the operating system:
633 "info os procgroups" lists process groups
634 "info os files" lists file descriptors
635 "info os sockets" lists internet-domain sockets
636 "info os shm" lists shared-memory regions
637 "info os semaphores" lists semaphores
638 "info os msg" lists message queues
639 "info os modules" lists loaded kernel modules
641 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
642 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
643 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
644 options and inspect the probe arguments using the new $_probe_arg family
645 of convenience variables. You can obtain more information about SystemTap
646 in <http://sourceware.org/systemtap/>.
648 * GDB now supports reversible debugging on ARM, it allows you to
649 debug basic ARM and THUMB instructions, and provides
650 record/replay support.
652 * The option "symbol-reloading" has been deleted as it is no longer used.
656 ** GDB commands implemented in Python can now be put in command class
659 ** The "maint set python print-stack on|off" is now deleted.
661 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
662 apply "flag enum"-style pretty-printing to any enum.
664 ** gdb.lookup_symbol can now work when there is no current frame.
666 ** gdb.Symbol now has a 'line' attribute, holding the line number in
667 the source at which the symbol was defined.
669 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
670 method 'value'. The former indicates whether the symbol needs a
671 frame in order to compute its value, and the latter computes the
674 ** A new method 'referenced_value' on gdb.Value objects which can
675 dereference pointer as well as C++ reference values.
677 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
678 which return the global and static blocks (as gdb.Block objects),
679 of the underlying symbol table, respectively.
681 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
682 object associated with a PC value.
684 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
685 of the address range occupied by code for the current source line.
687 * Go language support.
688 GDB now supports debugging programs written in the Go programming
691 * GDBserver now supports stdio connections.
692 E.g. (gdb) target remote | ssh myhost gdbserver - hello
694 * The binary "gdbtui" can no longer be built or installed.
695 Use "gdb -tui" instead.
697 * GDB will now print "flag" enums specially. A flag enum is one where
698 all the enumerator values have no bits in common when pairwise
699 "and"ed. When printing a value whose type is a flag enum, GDB will
700 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
701 (gdb) print (enum E) 3
704 * The filename part of a linespec will now match trailing components
705 of a source file name. For example, "break gcc/expr.c:1000" will
706 now set a breakpoint in build/gcc/expr.c, but not
709 * The "info proc" and "generate-core-file" commands will now also
710 work on remote targets connected to GDBserver on Linux.
712 * The command "info catch" has been removed. It has been disabled
715 * The "catch exception" and "catch assert" commands now accept
716 a condition at the end of the command, much like the "break"
717 command does. For instance:
719 (gdb) catch exception Constraint_Error if Barrier = True
721 Previously, it was possible to add a condition to such catchpoints,
722 but it had to be done as a second step, after the catchpoint had been
723 created, using the "condition" command.
725 * The "info static-tracepoint-marker" command will now also work on
726 native Linux targets with in-process agent.
728 * GDB can now set breakpoints on inlined functions.
730 * The .gdb_index section has been updated to include symbols for
731 inlined functions. GDB will ignore older .gdb_index sections by
732 default, which could cause symbol files to be loaded more slowly
733 until their .gdb_index sections can be recreated. The new command
734 "set use-deprecated-index-sections on" will cause GDB to use any older
735 .gdb_index sections it finds. This will restore performance, but the
736 ability to set breakpoints on inlined functions will be lost in symbol
737 files with older .gdb_index sections.
739 The .gdb_index section has also been updated to record more information
740 about each symbol. This speeds up the "info variables", "info functions"
741 and "info types" commands when used with programs having the .gdb_index
742 section, as well as speeding up debugging with shared libraries using
743 the .gdb_index section.
745 * Ada support for GDB/MI Variable Objects has been added.
747 * GDB can now support 'breakpoint always-inserted mode' in 'record'
752 ** New command -info-os is the MI equivalent of "info os".
754 ** Output logs ("set logging" and related) now include MI output.
758 ** "set use-deprecated-index-sections on|off"
759 "show use-deprecated-index-sections on|off"
760 Controls the use of deprecated .gdb_index sections.
762 ** "catch load" and "catch unload" can be used to stop when a shared
763 library is loaded or unloaded, respectively.
765 ** "enable count" can be used to auto-disable a breakpoint after
768 ** "info vtbl" can be used to show the virtual method tables for
769 C++ and Java objects.
771 ** "explore" and its sub commands "explore value" and "explore type"
772 can be used to recursively explore values and types of
773 expressions. These commands are available only if GDB is
774 configured with '--with-python'.
776 ** "info auto-load" shows status of all kinds of auto-loaded files,
777 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
778 sequences of commands files, "info auto-load python-scripts"
779 shows status of auto-loading Python script files,
780 "info auto-load local-gdbinit" shows status of loading init file
781 (.gdbinit) from current directory and "info auto-load libthread-db" shows
782 status of inferior specific thread debugging shared library loading.
784 ** "info auto-load-scripts", "set auto-load-scripts on|off"
785 and "show auto-load-scripts" commands have been deprecated, use their
786 "info auto-load python-scripts", "set auto-load python-scripts on|off"
787 and "show auto-load python-scripts" counterparts instead.
789 ** "dprintf location,format,args..." creates a dynamic printf, which
790 is basically a breakpoint that does a printf and immediately
791 resumes your program's execution, so it is like a printf that you
792 can insert dynamically at runtime instead of at compiletime.
794 ** "set print symbol"
796 Controls whether GDB attempts to display the symbol, if any,
797 corresponding to addresses it prints. This defaults to "on", but
798 you can set it to "off" to restore GDB's previous behavior.
800 * Deprecated commands
802 ** For the Renesas Super-H architecture, the "regs" command has been
803 deprecated, and "info all-registers" should be used instead.
807 Renesas RL78 rl78-*-elf
808 HP OpenVMS ia64 ia64-hp-openvms*
810 * GDBserver supports evaluation of breakpoint conditions. When
811 support is advertised by GDBserver, GDB may be told to send the
812 breakpoint conditions in bytecode form to GDBserver. GDBserver
813 will only report the breakpoint trigger to GDB when its condition
819 show mips compression
820 Select the compressed ISA encoding used in functions that have no symbol
821 information available. The encoding can be set to either of:
824 and is updated automatically from ELF file flags if available.
826 set breakpoint condition-evaluation
827 show breakpoint condition-evaluation
828 Control whether breakpoint conditions are evaluated by GDB ("host") or by
829 GDBserver ("target"). Default option "auto" chooses the most efficient
831 This option can improve debugger efficiency depending on the speed of the
835 Disable auto-loading globally.
838 Show auto-loading setting of all kinds of auto-loaded files.
840 set auto-load gdb-scripts on|off
841 show auto-load gdb-scripts
842 Control auto-loading of GDB canned sequences of commands files.
844 set auto-load python-scripts on|off
845 show auto-load python-scripts
846 Control auto-loading of Python script files.
848 set auto-load local-gdbinit on|off
849 show auto-load local-gdbinit
850 Control loading of init file (.gdbinit) from current directory.
852 set auto-load libthread-db on|off
853 show auto-load libthread-db
854 Control auto-loading of inferior specific thread debugging shared library.
856 set auto-load scripts-directory <dir1>[:<dir2>...]
857 show auto-load scripts-directory
858 Set a list of directories from which to load auto-loaded scripts.
859 Automatically loaded Python scripts and GDB scripts are located in one
860 of the directories listed by this option.
861 The delimiter (':' above) may differ according to the host platform.
863 set auto-load safe-path <dir1>[:<dir2>...]
864 show auto-load safe-path
865 Set a list of directories from which it is safe to auto-load files.
866 The delimiter (':' above) may differ according to the host platform.
868 set debug auto-load on|off
870 Control display of debugging info for auto-loading the files above.
872 set dprintf-style gdb|call|agent
874 Control the way in which a dynamic printf is performed; "gdb"
875 requests a GDB printf command, while "call" causes dprintf to call a
876 function in the inferior. "agent" requests that the target agent
877 (such as GDBserver) do the printing.
879 set dprintf-function <expr>
880 show dprintf-function
881 set dprintf-channel <expr>
883 Set the function and optional first argument to the call when using
884 the "call" style of dynamic printf.
886 set disconnected-dprintf on|off
887 show disconnected-dprintf
888 Control whether agent-style dynamic printfs continue to be in effect
889 after GDB disconnects.
891 * New configure options
894 Configure default value for the 'set auto-load scripts-directory'
895 setting above. It defaults to '$debugdir:$datadir/auto-load',
896 $debugdir representing global debugging info directories (available
897 via 'show debug-file-directory') and $datadir representing GDB's data
898 directory (available via 'show data-directory').
900 --with-auto-load-safe-path
901 Configure default value for the 'set auto-load safe-path' setting
902 above. It defaults to the --with-auto-load-dir setting.
904 --without-auto-load-safe-path
905 Set 'set auto-load safe-path' to '/', effectively disabling this
910 z0/z1 conditional breakpoints extension
912 The z0/z1 breakpoint insertion packets have been extended to carry
913 a list of conditional expressions over to the remote stub depending on the
914 condition evaluation mode. The use of this extension can be controlled
915 via the "set remote conditional-breakpoints-packet" command.
919 Specify the signals which the remote stub may pass to the debugged
920 program without GDB involvement.
922 * New command line options
924 --init-command=FILE, -ix Like --command, -x but execute it
925 before loading inferior.
926 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
927 execute it before loading inferior.
929 *** Changes in GDB 7.4
931 * GDB now handles ambiguous linespecs more consistently; the existing
932 FILE:LINE support has been expanded to other types of linespecs. A
933 breakpoint will now be set on all matching locations in all
934 inferiors, and locations will be added or removed according to
937 * GDB now allows you to skip uninteresting functions and files when
938 stepping with the "skip function" and "skip file" commands.
940 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
941 and "show remote hardware-watchpoint-length-limit". These allows to
942 set or show the maximum length limit (in bytes) of a remote
943 target hardware watchpoint.
945 This allows e.g. to use "unlimited" hardware watchpoints with the
946 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
947 watchpoints are slower than real hardware watchpoints but are
948 significantly faster than gdb software watchpoints.
952 ** The register_pretty_printer function in module gdb.printing now takes
953 an optional `replace' argument. If True, the new printer replaces any
956 ** The "maint set python print-stack on|off" command has been
957 deprecated and will be deleted in GDB 7.5.
958 A new command: "set python print-stack none|full|message" has
959 replaced it. Additionally, the default for "print-stack" is
960 now "message", which just prints the error message without
963 ** A prompt substitution hook (prompt_hook) is now available to the
966 ** A new Python module, gdb.prompt has been added to the GDB Python
967 modules library. This module provides functionality for
968 escape sequences in prompts (used by set/show
969 extended-prompt). These escape sequences are replaced by their
972 ** Python commands and convenience-functions located in
973 'data-directory'/python/gdb/command and
974 'data-directory'/python/gdb/function are now automatically loaded
977 ** Blocks now provide four new attributes. global_block and
978 static_block will return the global and static blocks
979 respectively. is_static and is_global are boolean attributes
980 that indicate if the block is one of those two types.
982 ** Symbols now provide the "type" attribute, the type of the symbol.
984 ** The "gdb.breakpoint" function has been deprecated in favor of
987 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
988 of a function. This class is based on the "finish" command
989 available in the CLI.
991 ** Type objects for struct and union types now allow access to
992 the fields using standard Python dictionary (mapping) methods.
993 For example, "some_type['myfield']" now works, as does
996 ** A new event "gdb.new_objfile" has been added, triggered by loading a
999 ** A new function, "deep_items" has been added to the gdb.types
1000 module in the GDB Python modules library. This function returns
1001 an iterator over the fields of a struct or union type. Unlike
1002 the standard Python "iteritems" method, it will recursively traverse
1003 any anonymous fields.
1007 ** "*stopped" events can report several new "reason"s, such as
1010 ** Breakpoint changes are now notified using new async records, like
1011 "=breakpoint-modified".
1013 ** New command -ada-task-info.
1015 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1016 $sdir specifies the default system locations of shared libraries.
1017 $pdir specifies the directory where the libpthread used by the application
1020 GDB no longer looks in $sdir and $pdir after it has searched the directories
1021 mentioned in libthread-db-search-path. If you want to search those
1022 directories, they must be specified in libthread-db-search-path.
1023 The default value of libthread-db-search-path on GNU/Linux and Solaris
1024 systems is now "$sdir:$pdir".
1026 $pdir is not supported by gdbserver, it is currently ignored.
1027 $sdir is supported by gdbserver.
1029 * New configure option --with-iconv-bin.
1030 When using the internationalization support like the one in the GNU C
1031 library, GDB will invoke the "iconv" program to get a list of supported
1032 character sets. If this program lives in a non-standard location, one can
1033 use this option to specify where to find it.
1035 * When natively debugging programs on PowerPC BookE processors running
1036 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1037 watchpoints, which specify a mask in addition to an address to watch.
1038 The mask specifies that some bits of an address (the bits which are
1039 reset in the mask) should be ignored when matching the address accessed
1040 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1041 section in the user manual for more details.
1043 * The new option --once causes GDBserver to stop listening for connections once
1044 the first connection is made. The listening port used by GDBserver will
1045 become available after that.
1047 * New commands "info macros" and "alias" have been added.
1049 * New function parameters suffix @entry specifies value of function parameter
1050 at the time the function got called. Entry values are available only since
1056 "!" is now an alias of the "shell" command.
1057 Note that no space is needed between "!" and SHELL COMMAND.
1061 watch EXPRESSION mask MASK_VALUE
1062 The watch command now supports the mask argument which allows creation
1063 of masked watchpoints, if the current architecture supports this feature.
1065 info auto-load-scripts [REGEXP]
1066 This command was formerly named "maintenance print section-scripts".
1067 It is now generally useful and is no longer a maintenance-only command.
1069 info macro [-all] [--] MACRO
1070 The info macro command has new options `-all' and `--'. The first for
1071 printing all definitions of a macro. The second for explicitly specifying
1072 the end of arguments and the beginning of the macro name in case the macro
1073 name starts with a hyphen.
1075 collect[/s] EXPRESSIONS
1076 The tracepoint collect command now takes an optional modifier "/s"
1077 that directs it to dereference pointer-to-character types and
1078 collect the bytes of memory up to a zero byte. The behavior is
1079 similar to what you see when you use the regular print command on a
1080 string. An optional integer following the "/s" sets a bound on the
1081 number of bytes that will be collected.
1084 The trace start command now interprets any supplied arguments as a
1085 note to be recorded with the trace run, with an effect similar to
1086 setting the variable trace-notes.
1089 The trace stop command now interprets any arguments as a note to be
1090 mentioned along with the tstatus report that the trace was stopped
1091 with a command. The effect is similar to setting the variable
1094 * Tracepoints can now be enabled and disabled at any time after a trace
1095 experiment has been started using the standard "enable" and "disable"
1096 commands. It is now possible to start a trace experiment with no enabled
1097 tracepoints; GDB will display a warning, but will allow the experiment to
1098 begin, assuming that tracepoints will be enabled as needed while the trace
1101 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1102 locations with 4-byte instructions, when they were previously
1103 limited to locations with instructions of 5 bytes or longer.
1107 set debug dwarf2-read
1108 show debug dwarf2-read
1109 Turns on or off display of debugging messages related to reading
1110 DWARF debug info. The default is off.
1112 set debug symtab-create
1113 show debug symtab-create
1114 Turns on or off display of debugging messages related to symbol table
1115 creation. The default is off.
1118 show extended-prompt
1119 Set the GDB prompt, and allow escape sequences to be inserted to
1120 display miscellaneous information (see 'help set extended-prompt'
1121 for the list of sequences). This prompt (and any information
1122 accessed through the escape sequences) is updated every time the
1123 prompt is displayed.
1125 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1126 show print entry-values
1127 Set printing of frame argument values at function entry. In some cases
1128 GDB can determine the value of function argument which was passed by the
1129 function caller, even if the value was modified inside the called function.
1131 set debug entry-values
1132 show debug entry-values
1133 Control display of debugging info for determining frame argument values at
1134 function entry and virtual tail call frames.
1136 set basenames-may-differ
1137 show basenames-may-differ
1138 Set whether a source file may have multiple base names.
1139 (A "base name" is the name of a file with the directory part removed.
1140 Example: The base name of "/home/user/hello.c" is "hello.c".)
1141 If set, GDB will canonicalize file names (e.g., expand symlinks)
1142 before comparing them. Canonicalization is an expensive operation,
1143 but it allows the same file be known by more than one base name.
1144 If not set (the default), all source files are assumed to have just
1145 one base name, and gdb will do file name comparisons more efficiently.
1151 Set a user name and notes for the current and any future trace runs.
1152 This is useful for long-running and/or disconnected traces, to
1153 inform others (or yourself) as to who is running the trace, supply
1154 contact information, or otherwise explain what is going on.
1156 set trace-stop-notes
1157 show trace-stop-notes
1158 Set a note attached to the trace run, that is displayed when the
1159 trace has been stopped by a tstop command. This is useful for
1160 instance as an explanation, if you are stopping a trace run that was
1161 started by someone else.
1163 * New remote packets
1167 Dynamically enable a tracepoint in a started trace experiment.
1171 Dynamically disable a tracepoint in a started trace experiment.
1175 Set the user and notes of the trace run.
1179 Query the current status of a tracepoint.
1183 Query the minimum length of instruction at which a fast tracepoint may
1186 * Dcache size (number of lines) and line-size are now runtime-configurable
1187 via "set dcache line" and "set dcache line-size" commands.
1191 Texas Instruments TMS320C6x tic6x-*-*
1195 Renesas RL78 rl78-*-elf
1197 *** Changes in GDB 7.3.1
1199 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1201 *** Changes in GDB 7.3
1203 * GDB has a new command: "thread find [REGEXP]".
1204 It finds the thread id whose name, target id, or thread extra info
1205 matches the given regular expression.
1207 * The "catch syscall" command now works on mips*-linux* targets.
1209 * The -data-disassemble MI command now supports modes 2 and 3 for
1210 dumping the instruction opcodes.
1212 * New command line options
1214 -data-directory DIR Specify DIR as the "data-directory".
1215 This is mostly for testing purposes.
1217 * The "maint set python auto-load on|off" command has been renamed to
1218 "set auto-load-scripts on|off".
1220 * GDB has a new command: "set directories".
1221 It is like the "dir" command except that it replaces the
1222 source path list instead of augmenting it.
1224 * GDB now understands thread names.
1226 On GNU/Linux, "info threads" will display the thread name as set by
1227 prctl or pthread_setname_np.
1229 There is also a new command, "thread name", which can be used to
1230 assign a name internally for GDB to display.
1233 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1234 has been integrated into GDB.
1238 ** The function gdb.Write now accepts an optional keyword 'stream'.
1239 This keyword, when provided, will direct the output to either
1240 stdout, stderr, or GDB's logging output.
1242 ** Parameters can now be be sub-classed in Python, and in particular
1243 you may implement the get_set_doc and get_show_doc functions.
1244 This improves how Parameter set/show documentation is processed
1245 and allows for more dynamic content.
1247 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1248 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1249 have an is_valid method.
1251 ** Breakpoints can now be sub-classed in Python, and in particular
1252 you may implement a 'stop' function that is executed each time
1253 the inferior reaches that breakpoint.
1255 ** New function gdb.lookup_global_symbol looks up a global symbol.
1257 ** GDB values in Python are now callable if the value represents a
1258 function. For example, if 'some_value' represents a function that
1259 takes two integer parameters and returns a value, you can call
1260 that function like so:
1262 result = some_value (10,20)
1264 ** Module gdb.types has been added.
1265 It contains a collection of utilities for working with gdb.Types objects:
1266 get_basic_type, has_field, make_enum_dict.
1268 ** Module gdb.printing has been added.
1269 It contains utilities for writing and registering pretty-printers.
1270 New classes: PrettyPrinter, SubPrettyPrinter,
1271 RegexpCollectionPrettyPrinter.
1272 New function: register_pretty_printer.
1274 ** New commands "info pretty-printers", "enable pretty-printer" and
1275 "disable pretty-printer" have been added.
1277 ** gdb.parameter("directories") is now available.
1279 ** New function gdb.newest_frame returns the newest frame in the
1282 ** The gdb.InferiorThread class has a new "name" attribute. This
1283 holds the thread's name.
1285 ** Python Support for Inferior events.
1286 Python scripts can add observers to be notified of events
1287 occurring in the process being debugged.
1288 The following events are currently supported:
1289 - gdb.events.cont Continue event.
1290 - gdb.events.exited Inferior exited event.
1291 - gdb.events.stop Signal received, and Breakpoint hit events.
1295 ** GDB now puts template parameters in scope when debugging in an
1296 instantiation. For example, if you have:
1298 template<int X> int func (void) { return X; }
1300 then if you step into func<5>, "print X" will show "5". This
1301 feature requires proper debuginfo support from the compiler; it
1302 was added to GCC 4.5.
1304 ** The motion commands "next", "finish", "until", and "advance" now
1305 work better when exceptions are thrown. In particular, GDB will
1306 no longer lose control of the inferior; instead, the GDB will
1307 stop the inferior at the point at which the exception is caught.
1308 This functionality requires a change in the exception handling
1309 code that was introduced in GCC 4.5.
1311 * GDB now follows GCC's rules on accessing volatile objects when
1312 reading or writing target state during expression evaluation.
1313 One notable difference to prior behavior is that "print x = 0"
1314 no longer generates a read of x; the value of the assignment is
1315 now always taken directly from the value being assigned.
1317 * GDB now has some support for using labels in the program's source in
1318 linespecs. For instance, you can use "advance label" to continue
1319 execution to a label.
1321 * GDB now has support for reading and writing a new .gdb_index
1322 section. This section holds a fast index of DWARF debugging
1323 information and can be used to greatly speed up GDB startup and
1324 operation. See the documentation for `save gdb-index' for details.
1326 * The "watch" command now accepts an optional "-location" argument.
1327 When used, this causes GDB to watch the memory referred to by the
1328 expression. Such a watchpoint is never deleted due to it going out
1331 * GDB now supports thread debugging of core dumps on GNU/Linux.
1333 GDB now activates thread debugging using the libthread_db library
1334 when debugging GNU/Linux core dumps, similarly to when debugging
1335 live processes. As a result, when debugging a core dump file, GDB
1336 is now able to display pthread_t ids of threads. For example, "info
1337 threads" shows the same output as when debugging the process when it
1338 was live. In earlier releases, you'd see something like this:
1341 * 1 LWP 6780 main () at main.c:10
1343 While now you see this:
1346 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1348 It is also now possible to inspect TLS variables when debugging core
1351 When debugging a core dump generated on a machine other than the one
1352 used to run GDB, you may need to point GDB at the correct
1353 libthread_db library with the "set libthread-db-search-path"
1354 command. See the user manual for more details on this command.
1356 * When natively debugging programs on PowerPC BookE processors running
1357 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1358 which stop execution of the inferior whenever it executes an instruction
1359 at any address within the specified range. See the "PowerPC Embedded"
1360 section in the user manual for more details.
1362 * New features in the GDB remote stub, GDBserver
1364 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1365 and i686 LynxOS (version 5.x).
1367 ** GDBserver is now supported on Blackfin Linux.
1369 * New native configurations
1371 ia64 HP-UX ia64-*-hpux*
1375 Analog Devices, Inc. Blackfin Processor bfin-*
1377 * Ada task switching is now supported on sparc-elf targets when
1378 debugging a program using the Ravenscar Profile. For more information,
1379 see the "Tasking Support when using the Ravenscar Profile" section
1380 in the GDB user manual.
1382 * Guile support was removed.
1384 * New features in the GNU simulator
1386 ** The --map-info flag lists all known core mappings.
1388 ** CFI flashes may be simulated via the "cfi" device.
1390 *** Changes in GDB 7.2
1392 * Shared library support for remote targets by default
1394 When GDB is configured for a generic, non-OS specific target, like
1395 for example, --target=arm-eabi or one of the many *-*-elf targets,
1396 GDB now queries remote stubs for loaded shared libraries using the
1397 `qXfer:libraries:read' packet. Previously, shared library support
1398 was always disabled for such configurations.
1402 ** Argument Dependent Lookup (ADL)
1404 In C++ ADL lookup directs function search to the namespaces of its
1405 arguments even if the namespace has not been imported.
1415 Here the compiler will search for `foo' in the namespace of 'b'
1416 and find A::foo. GDB now supports this. This construct is commonly
1417 used in the Standard Template Library for operators.
1419 ** Improved User Defined Operator Support
1421 In addition to member operators, GDB now supports lookup of operators
1422 defined in a namespace and imported with a `using' directive, operators
1423 defined in the global scope, operators imported implicitly from an
1424 anonymous namespace, and the ADL operators mentioned in the previous
1426 GDB now also supports proper overload resolution for all the previously
1427 mentioned flavors of operators.
1429 ** static const class members
1431 Printing of static const class members that are initialized in the
1432 class definition has been fixed.
1434 * Windows Thread Information Block access.
1436 On Windows targets, GDB now supports displaying the Windows Thread
1437 Information Block (TIB) structure. This structure is visible either
1438 by using the new command `info w32 thread-information-block' or, by
1439 dereferencing the new convenience variable named `$_tlb', a
1440 thread-specific pointer to the TIB. This feature is also supported
1441 when remote debugging using GDBserver.
1443 * Static tracepoints
1445 Static tracepoints are calls in the user program into a tracing
1446 library. One such library is a port of the LTTng kernel tracer to
1447 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1448 When debugging with GDBserver, GDB now supports combining the GDB
1449 tracepoint machinery with such libraries. For example: the user can
1450 use GDB to probe a static tracepoint marker (a call from the user
1451 program into the tracing library) with the new "strace" command (see
1452 "New commands" below). This creates a "static tracepoint" in the
1453 breakpoint list, that can be manipulated with the same feature set
1454 as fast and regular tracepoints. E.g., collect registers, local and
1455 global variables, collect trace state variables, and define
1456 tracepoint conditions. In addition, the user can collect extra
1457 static tracepoint marker specific data, by collecting the new
1458 $_sdata internal variable. When analyzing the trace buffer, you can
1459 inspect $_sdata like any other variable available to GDB. For more
1460 information, see the "Tracepoints" chapter in GDB user manual. New
1461 remote packets have been defined to support static tracepoints, see
1462 the "New remote packets" section below.
1464 * Better reconstruction of tracepoints after disconnected tracing
1466 GDB will attempt to download the original source form of tracepoint
1467 definitions when starting a trace run, and then will upload these
1468 upon reconnection to the target, resulting in a more accurate
1469 reconstruction of the tracepoints that are in use on the target.
1473 You can now exercise direct control over the ways that GDB can
1474 affect your program. For instance, you can disallow the setting of
1475 breakpoints, so that the program can run continuously (assuming
1476 non-stop mode). In addition, the "observer" variable is available
1477 to switch all of the different controls; in observer mode, GDB
1478 cannot affect the target's behavior at all, which is useful for
1479 tasks like diagnosing live systems in the field.
1481 * The new convenience variable $_thread holds the number of the
1484 * New remote packets
1488 Return the address of the Windows Thread Information Block of a given thread.
1492 In response to several of the tracepoint packets, the target may now
1493 also respond with a number of intermediate `qRelocInsn' request
1494 packets before the final result packet, to have GDB handle
1495 relocating an instruction to execute at a different address. This
1496 is particularly useful for stubs that support fast tracepoints. GDB
1497 reports support for this feature in the qSupported packet.
1501 List static tracepoint markers in the target program.
1505 List static tracepoint markers at a given address in the target
1508 qXfer:statictrace:read
1510 Read the static trace data collected (by a `collect $_sdata'
1511 tracepoint action). The remote stub reports support for this packet
1512 to gdb's qSupported query.
1516 Send the current settings of GDB's permission flags.
1520 Send part of the source (textual) form of a tracepoint definition,
1521 which includes location, conditional, and action list.
1523 * The source command now accepts a -s option to force searching for the
1524 script in the source search path even if the script name specifies
1527 * New features in the GDB remote stub, GDBserver
1529 - GDBserver now support tracepoints (including fast tracepoints, and
1530 static tracepoints). The feature is currently supported by the
1531 i386-linux and amd64-linux builds. See the "Tracepoints support
1532 in gdbserver" section in the manual for more information.
1534 GDBserver JIT compiles the tracepoint's conditional agent
1535 expression bytecode into native code whenever possible for low
1536 overhead dynamic tracepoints conditionals. For such tracepoints,
1537 an expression that examines program state is evaluated when the
1538 tracepoint is reached, in order to determine whether to capture
1539 trace data. If the condition is simple and false, processing the
1540 tracepoint finishes very quickly and no data is gathered.
1542 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1543 for static tracepoints support.
1545 - GDBserver now supports x86_64 Windows 64-bit debugging.
1547 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1548 it understands register description.
1550 * The --batch flag now disables pagination and queries.
1552 * X86 general purpose registers
1554 GDB now supports reading/writing byte, word and double-word x86
1555 general purpose registers directly. This means you can use, say,
1556 $ah or $ax to refer, respectively, to the byte register AH and
1557 16-bit word register AX that are actually portions of the 32-bit
1558 register EAX or 64-bit register RAX.
1560 * The `commands' command now accepts a range of breakpoints to modify.
1561 A plain `commands' following a command that creates multiple
1562 breakpoints affects all the breakpoints set by that command. This
1563 applies to breakpoints set by `rbreak', and also applies when a
1564 single `break' command creates multiple breakpoints (e.g.,
1565 breakpoints on overloaded c++ functions).
1567 * The `rbreak' command now accepts a filename specification as part of
1568 its argument, limiting the functions selected by the regex to those
1569 in the specified file.
1571 * Support for remote debugging Windows and SymbianOS shared libraries
1572 from Unix hosts has been improved. Non Windows GDB builds now can
1573 understand target reported file names that follow MS-DOS based file
1574 system semantics, such as file names that include drive letters and
1575 use the backslash character as directory separator. This makes it
1576 possible to transparently use the "set sysroot" and "set
1577 solib-search-path" on Unix hosts to point as host copies of the
1578 target's shared libraries. See the new command "set
1579 target-file-system-kind" described below, and the "Commands to
1580 specify files" section in the user manual for more information.
1584 eval template, expressions...
1585 Convert the values of one or more expressions under the control
1586 of the string template to a command line, and call it.
1588 set target-file-system-kind unix|dos-based|auto
1589 show target-file-system-kind
1590 Set or show the assumed file system kind for target reported file
1593 save breakpoints <filename>
1594 Save all current breakpoint definitions to a file suitable for use
1595 in a later debugging session. To read the saved breakpoint
1596 definitions, use the `source' command.
1598 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1601 info static-tracepoint-markers
1602 Display information about static tracepoint markers in the target.
1604 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1605 Define a static tracepoint by probing a marker at the given
1606 function, line, address, or marker ID.
1610 Enable and disable observer mode.
1612 set may-write-registers on|off
1613 set may-write-memory on|off
1614 set may-insert-breakpoints on|off
1615 set may-insert-tracepoints on|off
1616 set may-insert-fast-tracepoints on|off
1617 set may-interrupt on|off
1618 Set individual permissions for GDB effects on the target. Note that
1619 some of these settings can have undesirable or surprising
1620 consequences, particularly when changed in the middle of a session.
1621 For instance, disabling the writing of memory can prevent
1622 breakpoints from being inserted, cause single-stepping to fail, or
1623 even crash your program, if you disable after breakpoints have been
1624 inserted. However, GDB should not crash.
1626 set record memory-query on|off
1627 show record memory-query
1628 Control whether to stop the inferior if memory changes caused
1629 by an instruction cannot be recorded.
1634 The disassemble command now supports "start,+length" form of two arguments.
1638 ** GDB now provides a new directory location, called the python directory,
1639 where Python scripts written for GDB can be installed. The location
1640 of that directory is <data-directory>/python, where <data-directory>
1641 is the GDB data directory. For more details, see section `Scripting
1642 GDB using Python' in the manual.
1644 ** The GDB Python API now has access to breakpoints, symbols, symbol
1645 tables, program spaces, inferiors, threads and frame's code blocks.
1646 Additionally, GDB Parameters can now be created from the API, and
1647 manipulated via set/show in the CLI.
1649 ** New functions gdb.target_charset, gdb.target_wide_charset,
1650 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1652 ** New exception gdb.GdbError.
1654 ** Pretty-printers are now also looked up in the current program space.
1656 ** Pretty-printers can now be individually enabled and disabled.
1658 ** GDB now looks for names of Python scripts to auto-load in a
1659 special section named `.debug_gdb_scripts', in addition to looking
1660 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1662 * Tracepoint actions were unified with breakpoint commands. In particular,
1663 there are no longer differences in "info break" output for breakpoints and
1664 tracepoints and the "commands" command can be used for both tracepoints and
1665 regular breakpoints.
1669 ARM Symbian arm*-*-symbianelf*
1671 * D language support.
1672 GDB now supports debugging programs written in the D programming
1675 * GDB now supports the extended ptrace interface for PowerPC which is
1676 available since Linux kernel version 2.6.34. This automatically enables
1677 any hardware breakpoints and additional hardware watchpoints available in
1678 the processor. The old ptrace interface exposes just one hardware
1679 watchpoint and no hardware breakpoints.
1681 * GDB is now able to use the Data Value Compare (DVC) register available on
1682 embedded PowerPC processors to implement in hardware simple watchpoint
1683 conditions of the form:
1685 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1687 This works in native GDB running on Linux kernels with the extended ptrace
1688 interface mentioned above.
1690 *** Changes in GDB 7.1
1694 ** Namespace Support
1696 GDB now supports importing of namespaces in C++. This enables the
1697 user to inspect variables from imported namespaces. Support for
1698 namepace aliasing has also been added. So, if a namespace is
1699 aliased in the current scope (e.g. namepace C=A; ) the user can
1700 print variables using the alias (e.g. (gdb) print C::x).
1704 All known bugs relating to the printing of virtual base class were
1705 fixed. It is now possible to call overloaded static methods using a
1710 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1711 and reinterpret_cast<> are now handled by the C++ expression parser.
1715 Xilinx MicroBlaze microblaze-*-*
1720 Xilinx MicroBlaze microblaze
1723 * Multi-program debugging.
1725 GDB now has support for multi-program (a.k.a. multi-executable or
1726 multi-exec) debugging. This allows for debugging multiple inferiors
1727 simultaneously each running a different program under the same GDB
1728 session. See "Debugging Multiple Inferiors and Programs" in the
1729 manual for more information. This implied some user visible changes
1730 in the multi-inferior support. For example, "info inferiors" now
1731 lists inferiors that are not running yet or that have exited
1732 already. See also "New commands" and "New options" below.
1734 * New tracing features
1736 GDB's tracepoint facility now includes several new features:
1738 ** Trace state variables
1740 GDB tracepoints now include support for trace state variables, which
1741 are variables managed by the target agent during a tracing
1742 experiment. They are useful for tracepoints that trigger each
1743 other, so for instance one tracepoint can count hits in a variable,
1744 and then a second tracepoint has a condition that is true when the
1745 count reaches a particular value. Trace state variables share the
1746 $-syntax of GDB convenience variables, and can appear in both
1747 tracepoint actions and condition expressions. Use the "tvariable"
1748 command to create, and "info tvariables" to view; see "Trace State
1749 Variables" in the manual for more detail.
1753 GDB now includes an option for defining fast tracepoints, which
1754 targets may implement more efficiently, such as by installing a jump
1755 into the target agent rather than a trap instruction. The resulting
1756 speedup can be by two orders of magnitude or more, although the
1757 tradeoff is that some program locations on some target architectures
1758 might not allow fast tracepoint installation, for instance if the
1759 instruction to be replaced is shorter than the jump. To request a
1760 fast tracepoint, use the "ftrace" command, with syntax identical to
1761 the regular trace command.
1763 ** Disconnected tracing
1765 It is now possible to detach GDB from the target while it is running
1766 a trace experiment, then reconnect later to see how the experiment
1767 is going. In addition, a new variable disconnected-tracing lets you
1768 tell the target agent whether to continue running a trace if the
1769 connection is lost unexpectedly.
1773 GDB now has the ability to save the trace buffer into a file, and
1774 then use that file as a target, similarly to you can do with
1775 corefiles. You can select trace frames, print data that was
1776 collected in them, and use tstatus to display the state of the
1777 tracing run at the moment that it was saved. To create a trace
1778 file, use "tsave <filename>", and to use it, do "target tfile
1781 ** Circular trace buffer
1783 You can ask the target agent to handle the trace buffer as a
1784 circular buffer, discarding the oldest trace frames to make room for
1785 newer ones, by setting circular-trace-buffer to on. This feature may
1786 not be available for all target agents.
1791 The disassemble command, when invoked with two arguments, now requires
1792 the arguments to be comma-separated.
1795 The info variables command now displays variable definitions. Files
1796 which only declare a variable are not shown.
1799 The source command is now capable of sourcing Python scripts.
1800 This feature is dependent on the debugger being build with Python
1803 Related to this enhancement is also the introduction of a new command
1804 "set script-extension" (see below).
1806 * New commands (for set/show, see "New options" below)
1808 record save [<FILENAME>]
1809 Save a file (in core file format) containing the process record
1810 execution log for replay debugging at a later time.
1812 record restore <FILENAME>
1813 Restore the process record execution log that was saved at an
1814 earlier time, for replay debugging.
1816 add-inferior [-copies <N>] [-exec <FILENAME>]
1819 clone-inferior [-copies <N>] [ID]
1820 Make a new inferior ready to execute the same program another
1821 inferior has loaded.
1826 maint info program-spaces
1827 List the program spaces loaded into GDB.
1829 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1830 show remote interrupt-sequence
1831 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1832 as the sequence to the remote target in order to interrupt the execution.
1833 Ctrl-C is a default. Some system prefers BREAK which is high level of
1834 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1835 Magic SysRq g. It is BREAK signal and character 'g'.
1837 set remote interrupt-on-connect [on | off]
1838 show remote interrupt-on-connect
1839 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1840 remote target when gdb connects to it. This is needed when you debug
1843 set remotebreak [on | off]
1845 Deprecated. Use "set/show remote interrupt-sequence" instead.
1847 tvariable $NAME [ = EXP ]
1848 Create or modify a trace state variable.
1851 List trace state variables and their values.
1853 delete tvariable $NAME ...
1854 Delete one or more trace state variables.
1857 Evaluate the given expressions without collecting anything into the
1858 trace buffer. (Valid in tracepoint actions only.)
1860 ftrace FN / FILE:LINE / *ADDR
1861 Define a fast tracepoint at the given function, line, or address.
1863 * New expression syntax
1865 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1866 GDB now parses 0b101010 identically with 42.
1870 set follow-exec-mode new|same
1871 show follow-exec-mode
1872 Control whether GDB reuses the same inferior across an exec call or
1873 creates a new one. This is useful to be able to restart the old
1874 executable after the inferior having done an exec call.
1876 set default-collect EXPR, ...
1877 show default-collect
1878 Define a list of expressions to be collected at each tracepoint.
1879 This is a useful way to ensure essential items are not overlooked,
1880 such as registers or a critical global variable.
1882 set disconnected-tracing
1883 show disconnected-tracing
1884 If set to 1, the target is instructed to continue tracing if it
1885 loses its connection to GDB. If 0, the target is to stop tracing
1888 set circular-trace-buffer
1889 show circular-trace-buffer
1890 If set to on, the target is instructed to use a circular trace buffer
1891 and discard the oldest trace frames instead of stopping the trace due
1892 to a full trace buffer. If set to off, the trace stops when the buffer
1893 fills up. Some targets may not support this.
1895 set script-extension off|soft|strict
1896 show script-extension
1897 If set to "off", the debugger does not perform any script language
1898 recognition, and all sourced files are assumed to be GDB scripts.
1899 If set to "soft" (the default), files are sourced according to
1900 filename extension, falling back to GDB scripts if the first
1902 If set to "strict", files are sourced according to filename extension.
1904 set ada trust-PAD-over-XVS on|off
1905 show ada trust-PAD-over-XVS
1906 If off, activate a workaround against a bug in the debugging information
1907 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1908 the GCC sources for more information about the GNAT encoding and
1909 PAD types in particular). It is always safe to set this option to
1910 off, but this introduces a slight performance penalty. The default
1913 * Python API Improvements
1915 ** GDB provides the new class gdb.LazyString. This is useful in
1916 some pretty-printing cases. The new method gdb.Value.lazy_string
1917 provides a simple way to create objects of this type.
1919 ** The fields returned by gdb.Type.fields now have an
1920 `is_base_class' attribute.
1922 ** The new method gdb.Type.range returns the range of an array type.
1924 ** The new method gdb.parse_and_eval can be used to parse and
1925 evaluate an expression.
1927 * New remote packets
1930 Define a trace state variable.
1933 Get the current value of a trace state variable.
1936 Set desired tracing behavior upon disconnection.
1939 Set the trace buffer to be linear or circular.
1942 Get data about the tracepoints currently in use.
1946 Process record now works correctly with hardware watchpoints.
1948 Multiple bug fixes have been made to the mips-irix port, making it
1949 much more reliable. In particular:
1950 - Debugging threaded applications is now possible again. Previously,
1951 GDB would hang while starting the program, or while waiting for
1952 the program to stop at a breakpoint.
1953 - Attaching to a running process no longer hangs.
1954 - An error occurring while loading a core file has been fixed.
1955 - Changing the value of the PC register now works again. This fixes
1956 problems observed when using the "jump" command, or when calling
1957 a function from GDB, or even when assigning a new value to $pc.
1958 - With the "finish" and "return" commands, the return value for functions
1959 returning a small array is now correctly printed.
1960 - It is now possible to break on shared library code which gets executed
1961 during a shared library init phase (code executed while executing
1962 their .init section). Previously, the breakpoint would have no effect.
1963 - GDB is now able to backtrace through the signal handler for
1964 non-threaded programs.
1966 PIE (Position Independent Executable) programs debugging is now supported.
1967 This includes debugging execution of PIC (Position Independent Code) shared
1968 libraries although for that, it should be possible to run such libraries as an
1971 *** Changes in GDB 7.0
1973 * GDB now has an interface for JIT compilation. Applications that
1974 dynamically generate code can create symbol files in memory and register
1975 them with GDB. For users, the feature should work transparently, and
1976 for JIT developers, the interface is documented in the GDB manual in the
1977 "JIT Compilation Interface" chapter.
1979 * Tracepoints may now be conditional. The syntax is as for
1980 breakpoints; either an "if" clause appended to the "trace" command,
1981 or the "condition" command is available. GDB sends the condition to
1982 the target for evaluation using the same bytecode format as is used
1983 for tracepoint actions.
1985 * The disassemble command now supports: an optional /r modifier, print the
1986 raw instructions in hex as well as in symbolic form, and an optional /m
1987 modifier to print mixed source+assembly.
1989 * Process record and replay
1991 In a architecture environment that supports ``process record and
1992 replay'', ``process record and replay'' target can record a log of
1993 the process execution, and replay it with both forward and reverse
1996 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1997 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1998 set execution-direction {forward|reverse}, for targets that support
2001 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2002 feature is available with a native GDB running on kernel version
2005 * GDB now has support for multi-byte and wide character sets on the
2006 target. Strings whose character type is wchar_t, char16_t, or
2007 char32_t are now correctly printed. GDB supports wide- and unicode-
2008 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2009 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2010 `printf'. This feature requires iconv to work properly; if your
2011 system does not have a working iconv, GDB can use GNU libiconv. See
2012 the installation instructions for more information.
2014 * GDB now supports automatic retrieval of shared library files from
2015 remote targets. To use this feature, specify a system root that begins
2016 with the `remote:' prefix, either via the `set sysroot' command or via
2017 the `--with-sysroot' configure-time option.
2019 * "info sharedlibrary" now takes an optional regex of libraries to show,
2020 and it now reports if a shared library has no debugging information.
2022 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2023 now complete on file names.
2025 * When completing in expressions, gdb will attempt to limit
2026 completions to allowable structure or union fields, where appropriate.
2027 For instance, consider:
2029 # struct example { int f1; double f2; };
2030 # struct example variable;
2033 If the user types TAB at the end of this command line, the available
2034 completions will be "f1" and "f2".
2036 * Inlined functions are now supported. They show up in backtraces, and
2037 the "step", "next", and "finish" commands handle them automatically.
2039 * GDB now supports the token-splicing (##) and stringification (#)
2040 operators when expanding macros. It also supports variable-arity
2043 * GDB now supports inspecting extra signal information, exported by
2044 the new $_siginfo convenience variable. The feature is currently
2045 implemented on linux ARM, i386 and amd64.
2047 * GDB can now display the VFP floating point registers and NEON vector
2048 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2049 can provide these registers (requires Linux 2.6.30 or later). Remote
2050 and simulator targets may also provide them.
2052 * New remote packets
2055 Search memory for a sequence of bytes.
2058 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2059 operation over reliable transport links. Use of this packet is
2060 controlled by the `set remote noack-packet' command.
2063 Kill the process with the specified process ID. Use this in preference
2064 to `k' when multiprocess protocol extensions are supported.
2067 Obtains additional operating system information
2071 Read or write additional signal information.
2073 * Removed remote protocol undocumented extension
2075 An undocumented extension to the remote protocol's `S' stop reply
2076 packet that permited the stub to pass a process id was removed.
2077 Remote servers should use the `T' stop reply packet instead.
2079 * GDB now supports multiple function calling conventions according to the
2080 DWARF-2 DW_AT_calling_convention function attribute.
2082 * The SH target utilizes the aforementioned change to distinguish between gcc
2083 and Renesas calling convention. It also adds the new CLI commands
2084 `set/show sh calling-convention'.
2086 * GDB can now read compressed debug sections, as produced by GNU gold
2087 with the --compress-debug-sections=zlib flag.
2089 * 64-bit core files are now supported on AIX.
2091 * Thread switching is now supported on Tru64.
2093 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2094 which will be allocated using malloc later in program execution.
2096 * The qXfer:libraries:read remote procotol packet now allows passing a
2097 list of section offsets.
2099 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2100 conditions handling signals delivered during attach or thread creation
2101 have also been fixed.
2103 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2104 From the user's standpoint, all unqualified instances of True and False
2105 are treated as the standard definitions, regardless of context.
2107 * GDB now parses C++ symbol and type names more flexibly. For
2110 template<typename T> class C { };
2113 GDB will now correctly handle all of:
2115 ptype C<char const *>
2116 ptype C<char const*>
2117 ptype C<const char *>
2118 ptype C<const char*>
2120 * New features in the GDB remote stub, gdbserver
2122 - The "--wrapper" command-line argument tells gdbserver to use a
2123 wrapper program to launch programs for debugging.
2125 - On PowerPC and S/390 targets, it is now possible to use a single
2126 gdbserver executable to debug both 32-bit and 64-bit programs.
2127 (This requires gdbserver itself to be built as a 64-bit executable.)
2129 - gdbserver uses the new noack protocol mode for TCP connections to
2130 reduce communications latency, if also supported and enabled in GDB.
2132 - Support for the sparc64-linux-gnu target is now included in
2135 - The amd64-linux build of gdbserver now supports debugging both
2136 32-bit and 64-bit programs.
2138 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2139 now support hardware watchpoints, and will use them automatically
2144 GDB now has support for scripting using Python. Whether this is
2145 available is determined at configure time.
2147 New GDB commands can now be written in Python.
2149 * Ada tasking support
2151 Ada tasks can now be inspected in GDB. The following commands have
2155 Print the list of Ada tasks.
2157 Print detailed information about task number N.
2159 Print the task number of the current task.
2161 Switch the context of debugging to task number N.
2163 * Support for user-defined prefixed commands. The "define" command can
2164 add new commands to existing prefixes, e.g. "target".
2166 * Multi-inferior, multi-process debugging.
2168 GDB now has generalized support for multi-inferior debugging. See
2169 "Debugging Multiple Inferiors" in the manual for more information.
2170 Although availability still depends on target support, the command
2171 set is more uniform now. The GNU/Linux specific multi-forks support
2172 has been migrated to this new framework. This implied some user
2173 visible changes; see "New commands" and also "Removed commands"
2176 * Target descriptions can now describe the target OS ABI. See the
2177 "Target Description Format" section in the user manual for more
2180 * Target descriptions can now describe "compatible" architectures
2181 to indicate that the target can execute applications for a different
2182 architecture in addition to those for the main target architecture.
2183 See the "Target Description Format" section in the user manual for
2186 * Multi-architecture debugging.
2188 GDB now includes general supports for debugging applications on
2189 hybrid systems that use more than one single processor architecture
2190 at the same time. Each such hybrid architecture still requires
2191 specific support to be added. The only hybrid architecture supported
2192 in this version of GDB is the Cell Broadband Engine.
2194 * GDB now supports integrated debugging of Cell/B.E. applications that
2195 use both the PPU and SPU architectures. To enable support for hybrid
2196 Cell/B.E. debugging, you need to configure GDB to support both the
2197 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2198 --enable-targets configure option.
2200 * Non-stop mode debugging.
2202 For some targets, GDB now supports an optional mode of operation in
2203 which you can examine stopped threads while other threads continue
2204 to execute freely. This is referred to as non-stop mode, with the
2205 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2206 section in the user manual for more information.
2208 To be able to support remote non-stop debugging, a remote stub needs
2209 to implement the non-stop mode remote protocol extensions, as
2210 described in the "Remote Non-Stop" section of the user manual. The
2211 GDB remote stub, gdbserver, has been adjusted to support these
2212 extensions on linux targets.
2214 * New commands (for set/show, see "New options" below)
2216 catch syscall [NAME(S) | NUMBER(S)]
2217 Catch system calls. Arguments, which should be names of system
2218 calls or their numbers, mean catch only those syscalls. Without
2219 arguments, every syscall will be caught. When the inferior issues
2220 any of the specified syscalls, GDB will stop and announce the system
2221 call, both when it is called and when its call returns. This
2222 feature is currently available with a native GDB running on the
2223 Linux Kernel, under the following architectures: x86, x86_64,
2224 PowerPC and PowerPC64.
2226 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2228 Search memory for a sequence of bytes.
2230 maint set python print-stack
2231 maint show python print-stack
2232 Show a stack trace when an error is encountered in a Python script.
2235 Invoke CODE by passing it to the Python interpreter.
2240 These allow macros to be defined, undefined, and listed
2244 Show operating system information about processes.
2247 List the inferiors currently under GDB's control.
2250 Switch focus to inferior number NUM.
2253 Detach from inferior number NUM.
2256 Kill inferior number NUM.
2260 set spu stop-on-load
2261 show spu stop-on-load
2262 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2264 set spu auto-flush-cache
2265 show spu auto-flush-cache
2266 Control whether to automatically flush the software-managed cache
2267 during Cell/B.E. debugging.
2269 set sh calling-convention
2270 show sh calling-convention
2271 Control the calling convention used when calling SH target functions.
2274 show debug timestamp
2275 Control display of timestamps with GDB debugging output.
2277 set disassemble-next-line
2278 show disassemble-next-line
2279 Control display of disassembled source lines or instructions when
2282 set remote noack-packet
2283 show remote noack-packet
2284 Set/show the use of remote protocol QStartNoAckMode packet. See above
2285 under "New remote packets."
2287 set remote query-attached-packet
2288 show remote query-attached-packet
2289 Control use of remote protocol `qAttached' (query-attached) packet.
2291 set remote read-siginfo-object
2292 show remote read-siginfo-object
2293 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2296 set remote write-siginfo-object
2297 show remote write-siginfo-object
2298 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2301 set remote reverse-continue
2302 show remote reverse-continue
2303 Control use of remote protocol 'bc' (reverse-continue) packet.
2305 set remote reverse-step
2306 show remote reverse-step
2307 Control use of remote protocol 'bs' (reverse-step) packet.
2309 set displaced-stepping
2310 show displaced-stepping
2311 Control displaced stepping mode. Displaced stepping is a way to
2312 single-step over breakpoints without removing them from the debuggee.
2313 Also known as "out-of-line single-stepping".
2316 show debug displaced
2317 Control display of debugging info for displaced stepping.
2319 maint set internal-error
2320 maint show internal-error
2321 Control what GDB does when an internal error is detected.
2323 maint set internal-warning
2324 maint show internal-warning
2325 Control what GDB does when an internal warning is detected.
2330 Use a wrapper program to launch programs for debugging.
2332 set multiple-symbols (all|ask|cancel)
2333 show multiple-symbols
2334 The value of this variable can be changed to adjust the debugger behavior
2335 when an expression or a breakpoint location contains an ambiguous symbol
2336 name (an overloaded function name, for instance).
2338 set breakpoint always-inserted
2339 show breakpoint always-inserted
2340 Keep breakpoints always inserted in the target, as opposed to inserting
2341 them when resuming the target, and removing them when the target stops.
2342 This option can improve debugger performance on slow remote targets.
2344 set arm fallback-mode (arm|thumb|auto)
2345 show arm fallback-mode
2346 set arm force-mode (arm|thumb|auto)
2348 These commands control how ARM GDB determines whether instructions
2349 are ARM or Thumb. The default for both settings is auto, which uses
2350 the current CPSR value for instructions without symbols; previous
2351 versions of GDB behaved as if "set arm fallback-mode arm".
2353 set disable-randomization
2354 show disable-randomization
2355 Standalone programs run with the virtual address space randomization enabled
2356 by default on some platforms. This option keeps the addresses stable across
2357 multiple debugging sessions.
2361 Control whether other threads are stopped or not when some thread hits
2366 Requests that asynchronous execution is enabled in the target, if available.
2367 In this case, it's possible to resume target in the background, and interact
2368 with GDB while the target is running. "show target-async" displays the
2369 current state of asynchronous execution of the target.
2371 set target-wide-charset
2372 show target-wide-charset
2373 The target-wide-charset is the name of the character set that GDB
2374 uses when printing characters whose type is wchar_t.
2376 set tcp auto-retry (on|off)
2378 set tcp connect-timeout
2379 show tcp connect-timeout
2380 These commands allow GDB to retry failed TCP connections to a remote stub
2381 with a specified timeout period; this is useful if the stub is launched
2382 in parallel with GDB but may not be ready to accept connections immediately.
2384 set libthread-db-search-path
2385 show libthread-db-search-path
2386 Control list of directories which GDB will search for appropriate
2389 set schedule-multiple (on|off)
2390 show schedule-multiple
2391 Allow GDB to resume all threads of all processes or only threads of
2392 the current process.
2396 Use more aggressive caching for accesses to the stack. This improves
2397 performance of remote debugging (particularly backtraces) without
2398 affecting correctness.
2400 set interactive-mode (on|off|auto)
2401 show interactive-mode
2402 Control whether GDB runs in interactive mode (on) or not (off).
2403 When in interactive mode, GDB waits for the user to answer all
2404 queries. Otherwise, GDB does not wait and assumes the default
2405 answer. When set to auto (the default), GDB determines which
2406 mode to use based on the stdin settings.
2411 For program forks, this is replaced by the new more generic `info
2412 inferiors' command. To list checkpoints, you can still use the
2413 `info checkpoints' command, which was an alias for the `info forks'
2417 Replaced by the new `inferior' command. To switch between
2418 checkpoints, you can still use the `restart' command, which was an
2419 alias for the `fork' command.
2422 This is removed, since some targets don't have a notion of
2423 processes. To switch between processes, you can still use the
2424 `inferior' command using GDB's own inferior number.
2427 For program forks, this is replaced by the new more generic `kill
2428 inferior' command. To delete a checkpoint, you can still use the
2429 `delete checkpoint' command, which was an alias for the `delete
2433 For program forks, this is replaced by the new more generic `detach
2434 inferior' command. To detach a checkpoint, you can still use the
2435 `detach checkpoint' command, which was an alias for the `detach
2438 * New native configurations
2440 x86/x86_64 Darwin i[34567]86-*-darwin*
2442 x86_64 MinGW x86_64-*-mingw*
2446 Lattice Mico32 lm32-*
2447 x86 DICOS i[34567]86-*-dicos*
2448 x86_64 DICOS x86_64-*-dicos*
2451 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2452 (mingw32ce) debugging.
2458 These commands were actually not implemented on any target.
2460 *** Changes in GDB 6.8
2462 * New native configurations
2464 NetBSD/hppa hppa*-*netbsd*
2465 Xtensa GNU/Linux xtensa*-*-linux*
2469 NetBSD/hppa hppa*-*-netbsd*
2470 Xtensa GNU/Lunux xtensa*-*-linux*
2472 * Change in command line behavior -- corefiles vs. process ids.
2474 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2475 attaching to process NUMBER fails, GDB no longer attempts to open a
2476 core file named NUMBER. Attaching to a program using the -c option
2477 is no longer supported. Instead, use the '-p' or '--pid' options.
2479 * GDB can now be built as a native debugger for debugging Windows x86
2480 (mingw32) Portable Executable (PE) programs.
2482 * Pending breakpoints no longer change their number when their address
2485 * GDB now supports breakpoints with multiple locations,
2486 including breakpoints on C++ constructors, inside C++ templates,
2487 and in inlined functions.
2489 * GDB's ability to debug optimized code has been improved. GDB more
2490 accurately identifies function bodies and lexical blocks that occupy
2491 more than one contiguous range of addresses.
2493 * Target descriptions can now describe registers for PowerPC.
2495 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2496 registers on PowerPC targets.
2498 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2499 targets even when the libthread_db library is not available.
2501 * The GDB remote stub, gdbserver, now supports the new file transfer
2502 commands (remote put, remote get, and remote delete).
2504 * The GDB remote stub, gdbserver, now supports run and attach in
2505 extended-remote mode.
2507 * hppa*64*-*-hpux11* target broken
2508 The debugger is unable to start a program and fails with the following
2509 error: "Error trying to get information about dynamic linker".
2510 The gdb-6.7 release is also affected.
2512 * GDB now supports the --enable-targets= configure option to allow
2513 building a single GDB executable that supports multiple remote
2514 target architectures.
2516 * GDB now supports debugging C and C++ programs which use the
2517 Decimal Floating Point extension. In addition, the PowerPC target
2518 now has a set of pseudo-registers to inspect decimal float values
2519 stored in two consecutive float registers.
2521 * The -break-insert MI command can optionally create pending
2524 * Improved support for debugging Ada
2525 Many improvements to the Ada language support have been made. These
2527 - Better support for Ada2005 interface types
2528 - Improved handling of arrays and slices in general
2529 - Better support for Taft-amendment types
2530 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2532 - Improved command completion in Ada
2535 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2540 set print frame-arguments (all|scalars|none)
2541 show print frame-arguments
2542 The value of this variable can be changed to control which argument
2543 values should be printed by the debugger when displaying a frame.
2548 Transfer files to and from a remote target, and delete remote files.
2555 Transfer files to and from a remote target, and delete remote files.
2557 * New remote packets
2564 Open, close, read, write, and delete files on the remote system.
2567 Attach to an existing process on the remote system, in extended-remote
2571 Run a new process on the remote system, in extended-remote mode.
2573 *** Changes in GDB 6.7
2575 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2576 bfd, libiberty and opcodes, as revealed by static analysis donated by
2577 Coverity, Inc. (http://scan.coverity.com).
2579 * When looking up multiply-defined global symbols, GDB will now prefer the
2580 symbol definition in the current shared library if it was built using the
2581 -Bsymbolic linker option.
2583 * When the Text User Interface (TUI) is not configured, GDB will now
2584 recognize the -tui command-line option and print a message that the TUI
2587 * The GDB remote stub, gdbserver, now has lower overhead for high
2588 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2590 * GDB for MIPS targets now autodetects whether a remote target provides
2591 32-bit or 64-bit register values.
2593 * Support for C++ member pointers has been improved.
2595 * GDB now understands XML target descriptions, which specify the
2596 target's overall architecture. GDB can read a description from
2597 a local file or over the remote serial protocol.
2599 * Vectors of single-byte data use a new integer type which is not
2600 automatically displayed as character or string data.
2602 * The /s format now works with the print command. It displays
2603 arrays of single-byte integers and pointers to single-byte integers
2606 * Target descriptions can now describe target-specific registers,
2607 for architectures which have implemented the support (currently
2608 only ARM, M68K, and MIPS).
2610 * GDB and the GDB remote stub, gdbserver, now support the XScale
2613 * The GDB remote stub, gdbserver, has been updated to support
2614 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2615 has been rewritten to use the standard GDB remote protocol.
2617 * GDB can now step into C++ functions which are called through thunks.
2619 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2621 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2622 layout. It also supports a TextSeg= and DataSeg= response when only
2623 segment base addresses (rather than offsets) are available.
2625 * The /i format now outputs any trailing branch delay slot instructions
2626 immediately following the last instruction within the count specified.
2628 * The GDB remote protocol "T" stop reply packet now supports a
2629 "library" response. Combined with the new "qXfer:libraries:read"
2630 packet, this response allows GDB to debug shared libraries on targets
2631 where the operating system manages the list of loaded libraries (e.g.
2632 Windows and SymbianOS).
2634 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2635 (DLLs) on Windows and Windows CE targets.
2637 * GDB now supports a faster verification that a .debug file matches its binary
2638 according to its build-id signature, if the signature is present.
2644 Enable or disable hardware flow control (RTS/CTS) on the serial port
2645 when debugging using remote targets.
2647 set mem inaccessible-by-default
2648 show mem inaccessible-by-default
2649 If the target supplies a memory map, for instance via the remote
2650 protocol's "qXfer:memory-map:read" packet, setting this variable
2651 prevents GDB from accessing memory outside the memory map. This
2652 is useful for targets with memory mapped registers or which react
2653 badly to accesses of unmapped address space.
2655 set breakpoint auto-hw
2656 show breakpoint auto-hw
2657 If the target supplies a memory map, for instance via the remote
2658 protocol's "qXfer:memory-map:read" packet, setting this variable
2659 lets GDB use hardware breakpoints automatically for memory regions
2660 where it can not use software breakpoints. This covers both the
2661 "break" command and internal breakpoints used for other commands
2662 including "next" and "finish".
2665 catch exception unhandled
2666 Stop the program execution when Ada exceptions are raised.
2669 Stop the program execution when an Ada assertion failed.
2673 Set an alternate system root for target files. This is a more
2674 general version of "set solib-absolute-prefix", which is now
2675 an alias to "set sysroot".
2678 Provide extended SPU facility status information. This set of
2679 commands is available only when debugging the Cell/B.E. SPU
2682 * New native configurations
2684 OpenBSD/sh sh*-*openbsd*
2687 unset tdesc filename
2689 Use the specified local file as an XML target description, and do
2690 not query the target for its built-in description.
2694 OpenBSD/sh sh*-*-openbsd*
2695 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2696 Toshiba Media Processor mep-elf
2698 * New remote packets
2701 Ignore the specified signals; pass them directly to the debugged program
2702 without stopping other threads or reporting them to GDB.
2704 qXfer:features:read:
2705 Read an XML target description from the target, which describes its
2710 Read or write contents of an spufs file on the target system. These
2711 packets are available only on the Cell/B.E. SPU architecture.
2713 qXfer:libraries:read:
2714 Report the loaded shared libraries. Combined with new "T" packet
2715 response, this packet allows GDB to debug shared libraries on
2716 targets where the operating system manages the list of loaded
2717 libraries (e.g. Windows and SymbianOS).
2721 Support for these obsolete configurations has been removed.
2729 i[34567]86-*-lynxos*
2730 i[34567]86-*-netware*
2731 i[34567]86-*-sco3.2v5*
2732 i[34567]86-*-sco3.2v4*
2734 i[34567]86-*-sysv4.2*
2737 i[34567]86-*-unixware2*
2738 i[34567]86-*-unixware*
2747 * Other removed features
2754 Various m68k-only ROM monitors.
2761 Various Renesas ROM monitors and debugging interfaces for SH and
2766 Support for a Macraigor serial interface to on-chip debugging.
2767 GDB does not directly support the newer parallel or USB
2772 A debug information format. The predecessor to DWARF 2 and
2773 DWARF 3, which are still supported.
2775 Support for the HP aCC compiler on HP-UX/PA-RISC
2777 SOM-encapsulated symbolic debugging information, automatic
2778 invocation of pxdb, and the aCC custom C++ ABI. This does not
2779 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2780 with aCC can still be debugged on an assembly level.
2782 MIPS ".pdr" sections
2784 A MIPS-specific format used to describe stack frame layout
2785 in debugging information.
2789 GDB could work with an older version of Guile to debug
2790 the interpreter and Scheme programs running in it.
2792 set mips stack-arg-size
2793 set mips saved-gpreg-size
2795 Use "set mips abi" to control parameter passing for MIPS.
2797 *** Changes in GDB 6.6
2802 Cell Broadband Engine SPU spu-elf
2804 * GDB can now be configured as a cross-debugger targeting native Windows
2805 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2806 running on a Windows system over TCP/IP to debug Windows programs.
2808 * The GDB remote stub, gdbserver, has been updated to support Windows and
2809 Cygwin debugging. Both single-threaded and multi-threaded programs are
2812 * The "set trust-readonly-sections" command works again. This command was
2813 broken in GDB 6.3, 6.4, and 6.5.
2815 * The "load" command now supports writing to flash memory, if the remote
2816 stub provides the required support.
2818 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2819 longer requires symbolic debug information (e.g. DWARF-2).
2824 unset substitute-path
2825 show substitute-path
2826 Manage a list of substitution rules that GDB uses to rewrite the name
2827 of the directories where the sources are located. This can be useful
2828 for instance when the sources were moved to a different location
2829 between compilation and debugging.
2833 Print each CLI command as it is executed. Each command is prefixed with
2834 a number of `+' symbols representing the nesting depth.
2835 The source command now has a `-v' option to enable the same feature.
2839 The ARM Demon monitor support (RDP protocol, "target rdp").
2841 Kernel Object Display, an embedded debugging feature which only worked with
2842 an obsolete version of Cisco IOS.
2844 The 'set download-write-size' and 'show download-write-size' commands.
2846 * New remote packets
2849 Tell a stub about GDB client features, and request remote target features.
2850 The first feature implemented is PacketSize, which allows the target to
2851 specify the size of packets it can handle - to minimize the number of
2852 packets required and improve performance when connected to a remote
2856 Fetch an OS auxilliary vector from the remote stub. This packet is a
2857 more efficient replacement for qPart:auxv:read.
2859 qXfer:memory-map:read:
2860 Fetch a memory map from the remote stub, including information about
2861 RAM, ROM, and flash memory devices.
2866 Erase and program a flash memory device.
2868 * Removed remote packets
2871 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2872 used it, and only gdbserver implemented it.
2874 *** Changes in GDB 6.5
2878 Renesas M32C/M16C m32c-elf
2880 Morpho Technologies ms1 ms1-elf
2884 init-if-undefined Initialize a convenience variable, but
2885 only if it doesn't already have a value.
2887 The following commands are presently only implemented for native GNU/Linux:
2889 checkpoint Save a snapshot of the program state.
2891 restart <n> Return the program state to a
2892 previously saved state.
2894 info checkpoints List currently saved checkpoints.
2896 delete-checkpoint <n> Delete a previously saved checkpoint.
2898 set|show detach-on-fork Tell gdb whether to detach from a newly
2899 forked process, or to keep debugging it.
2901 info forks List forks of the user program that
2902 are available to be debugged.
2904 fork <n> Switch to debugging one of several
2905 forks of the user program that are
2906 available to be debugged.
2908 delete-fork <n> Delete a fork from the list of forks
2909 that are available to be debugged (and
2910 kill the forked process).
2912 detach-fork <n> Delete a fork from the list of forks
2913 that are available to be debugged (and
2914 allow the process to continue).
2918 Morpho Technologies ms2 ms1-elf
2920 * Improved Windows host support
2922 GDB now builds as a cross debugger hosted on i686-mingw32, including
2923 native console support, and remote communications using either
2924 network sockets or serial ports.
2926 * Improved Modula-2 language support
2928 GDB can now print most types in the Modula-2 syntax. This includes:
2929 basic types, set types, record types, enumerated types, range types,
2930 pointer types and ARRAY types. Procedure var parameters are correctly
2931 printed and hexadecimal addresses and character constants are also
2932 written in the Modula-2 syntax. Best results can be obtained by using
2933 GNU Modula-2 together with the -gdwarf-2 command line option.
2937 The ARM rdi-share module.
2939 The Netware NLM debug server.
2941 *** Changes in GDB 6.4
2943 * New native configurations
2945 OpenBSD/arm arm*-*-openbsd*
2946 OpenBSD/mips64 mips64-*-openbsd*
2950 Morpho Technologies ms1 ms1-elf
2952 * New command line options
2954 --batch-silent As for --batch, but totally silent.
2955 --return-child-result The debugger will exist with the same value
2956 the child (debugged) program exited with.
2957 --eval-command COMMAND, -ex COMMAND
2958 Execute a single GDB CLI command. This may be
2959 specified multiple times and in conjunction
2960 with the --command (-x) option.
2962 * Deprecated commands removed
2964 The following commands, that were deprecated in 2000, have been
2968 set|show arm disassembly-flavor set|show arm disassembler
2969 othernames set arm disassembler
2970 set|show remotedebug set|show debug remote
2971 set|show archdebug set|show debug arch
2972 set|show eventdebug set|show debug event
2975 * New BSD user-level threads support
2977 It is now possible to debug programs using the user-level threads
2978 library on OpenBSD and FreeBSD. Currently supported (target)
2981 FreeBSD/amd64 x86_64-*-freebsd*
2982 FreeBSD/i386 i386-*-freebsd*
2983 OpenBSD/i386 i386-*-openbsd*
2985 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2986 are not yet supported.
2988 * New support for Matsushita MN10300 w/sim added
2989 (Work in progress). mn10300-elf.
2991 * REMOVED configurations and files
2993 VxWorks and the XDR protocol *-*-vxworks
2994 Motorola MCORE mcore-*-*
2995 National Semiconductor NS32000 ns32k-*-*
2997 * New "set print array-indexes" command
2999 After turning this setting "on", GDB prints the index of each element
3000 when displaying arrays. The default is "off" to preserve the previous
3003 * VAX floating point support
3005 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3007 * User-defined command support
3009 In addition to using $arg0..$arg9 for argument passing, it is now possible
3010 to use $argc to determine now many arguments have been passed. See the
3011 section on user-defined commands in the user manual for more information.
3013 *** Changes in GDB 6.3:
3015 * New command line option
3017 GDB now accepts -l followed by a number to set the timeout for remote
3020 * GDB works with GCC -feliminate-dwarf2-dups
3022 GDB now supports a more compact representation of DWARF-2 debug
3023 information using DW_FORM_ref_addr references. These are produced
3024 by GCC with the option -feliminate-dwarf2-dups and also by some
3025 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3026 to use -feliminate-dwarf2-dups.
3028 * Internationalization
3030 When supported by the host system, GDB will be built with
3031 internationalization (libintl). The task of marking up the sources is
3032 continued, we're looking forward to our first translation.
3036 Initial support for debugging programs compiled with the GNAT
3037 implementation of the Ada programming language has been integrated
3038 into GDB. In this release, support is limited to expression evaluation.
3040 * New native configurations
3042 GNU/Linux/m32r m32r-*-linux-gnu
3046 GDB's remote protocol now includes support for the 'p' packet. This
3047 packet is used to fetch individual registers from a remote inferior.
3049 * END-OF-LIFE registers[] compatibility module
3051 GDB's internal register infrastructure has been completely rewritten.
3052 The new infrastructure making possible the implementation of key new
3053 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3056 GDB 6.3 will be the last release to include the the registers[]
3057 compatibility module that allowed out-of-date configurations to
3058 continue to work. This change directly impacts the following
3068 powerpc bdm protocol
3070 Unless there is activity to revive these configurations, they will be
3071 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3073 * OBSOLETE configurations and files
3075 Configurations that have been declared obsolete in this release have
3076 been commented out. Unless there is activity to revive these
3077 configurations, the next release of GDB will have their sources
3078 permanently REMOVED.
3087 *** Changes in GDB 6.2.1:
3089 * MIPS `break main; run' gave an heuristic-fence-post warning
3091 When attempting to run even a simple program, a warning about
3092 heuristic-fence-post being hit would be reported. This problem has
3095 * MIPS IRIX 'long double' crashed GDB
3097 When examining a long double variable, GDB would get a segmentation
3098 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3099 IRIX long double values).
3103 A bug in the VAX stack code was causing problems with the "next"
3104 command. This problem has been fixed.
3106 *** Changes in GDB 6.2:
3108 * Fix for ``many threads''
3110 On GNU/Linux systems that use the NPTL threads library, a program
3111 rapidly creating and deleting threads would confuse GDB leading to the
3114 ptrace: No such process.
3115 thread_db_get_info: cannot get thread info: generic error
3117 This problem has been fixed.
3119 * "-async" and "-noasync" options removed.
3121 Support for the broken "-noasync" option has been removed (it caused
3124 * New ``start'' command.
3126 This command runs the program until the begining of the main procedure.
3128 * New BSD Kernel Data Access Library (libkvm) interface
3130 Using ``target kvm'' it is now possible to debug kernel core dumps and
3131 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3132 platforms. Currently supported (native-only) configurations are:
3134 FreeBSD/amd64 x86_64-*-freebsd*
3135 FreeBSD/i386 i?86-*-freebsd*
3136 NetBSD/i386 i?86-*-netbsd*
3137 NetBSD/m68k m68*-*-netbsd*
3138 NetBSD/sparc sparc-*-netbsd*
3139 OpenBSD/amd64 x86_64-*-openbsd*
3140 OpenBSD/i386 i?86-*-openbsd*
3141 OpenBSD/m68k m68*-openbsd*
3142 OpenBSD/sparc sparc-*-openbsd*
3144 * Signal trampoline code overhauled
3146 Many generic problems with GDB's signal handling code have been fixed.
3147 These include: backtraces through non-contiguous stacks; recognition
3148 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3149 call; backtrace through a signal trampoline; step into and out of
3150 signal handlers; and single-stepping in the signal trampoline.
3152 Please note that kernel bugs are a limiting factor here. These
3153 features have been shown to work on an s390 GNU/Linux system that
3154 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3156 * Cygwin support for DWARF 2 added.
3158 * New native configurations
3160 GNU/Linux/hppa hppa*-*-linux*
3161 OpenBSD/hppa hppa*-*-openbsd*
3162 OpenBSD/m68k m68*-*-openbsd*
3163 OpenBSD/m88k m88*-*-openbsd*
3164 OpenBSD/powerpc powerpc-*-openbsd*
3165 NetBSD/vax vax-*-netbsd*
3166 OpenBSD/vax vax-*-openbsd*
3168 * END-OF-LIFE frame compatibility module
3170 GDB's internal frame infrastructure has been completely rewritten.
3171 The new infrastructure making it possible to support key new features
3172 including DWARF 2 Call Frame Information. To aid in the task of
3173 migrating old configurations to this new infrastructure, a
3174 compatibility module, that allowed old configurations to continue to
3175 work, was also included.
3177 GDB 6.2 will be the last release to include this frame compatibility
3178 module. This change directly impacts the following configurations:
3188 Unless there is activity to revive these configurations, they will be
3189 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3191 * REMOVED configurations and files
3193 Sun 3, running SunOS 3 m68*-*-sunos3*
3194 Sun 3, running SunOS 4 m68*-*-sunos4*
3195 Sun 2, running SunOS 3 m68000-*-sunos3*
3196 Sun 2, running SunOS 4 m68000-*-sunos4*
3197 Motorola 680x0 running LynxOS m68*-*-lynxos*
3198 AT&T 3b1/Unix pc m68*-att-*
3199 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3200 decstation mips-dec-* mips-little-*
3201 riscos mips-*-riscos* mips-*-sysv*
3202 sonymips mips-sony-*
3203 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3205 *** Changes in GDB 6.1.1:
3207 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3209 The TUI (Text-mode User Interface) is now built as part of a default
3210 GDB configuration. It is enabled by either selecting the TUI with the
3211 command line option "-i=tui" or by running the separate "gdbtui"
3212 program. For more information on the TUI, see the manual "Debugging
3215 * Pending breakpoint support (also included in GDB 6.1)
3217 Support has been added to allow you to specify breakpoints in shared
3218 libraries that have not yet been loaded. If a breakpoint location
3219 cannot be found, and the "breakpoint pending" option is set to auto,
3220 GDB queries you if you wish to make the breakpoint pending on a future
3221 shared-library load. If and when GDB resolves the breakpoint symbol,
3222 the pending breakpoint is removed as one or more regular breakpoints
3225 Pending breakpoints are very useful for GCJ Java debugging.
3227 * Fixed ISO-C build problems
3229 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3230 non ISO-C code that stopped them being built using a more strict ISO-C
3231 compiler (e.g., IBM's C compiler).
3233 * Fixed build problem on IRIX 5
3235 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3236 wasn't able to compile compile on an IRIX 5 system.
3238 * Added execute permission to gdb/gdbserver/configure
3240 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3241 permission. This bug would cause configure to fail on a number of
3242 systems (Solaris, IRIX). Ref: server/519.
3244 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3246 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3247 has been updated to use constant array sizes.
3249 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3251 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3252 its generated DWARF Call Frame Info. This encoding was causing GDB to
3253 panic, that panic has been fixed. Ref: gdb/1628.
3255 * Fixed a problem when examining parameters in shared library code.
3257 When examining parameters in optimized shared library code generated
3258 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3259 not available''. GDB now correctly displays the variable's value.
3261 *** Changes in GDB 6.1:
3263 * Removed --with-mmalloc
3265 Support for the mmalloc memory manager has been removed, as it
3266 conflicted with the internal gdb byte cache.
3268 * Changes in AMD64 configurations
3270 The AMD64 target now includes the %cs and %ss registers. As a result
3271 the AMD64 remote protocol has changed; this affects the floating-point
3272 and SSE registers. If you rely on those registers for your debugging,
3273 you should upgrade gdbserver on the remote side.
3275 * Revised SPARC target
3277 The SPARC target has been completely revised, incorporating the
3278 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3279 support for LynxOS and SunOS 4 has been dropped. Calling functions
3280 from within GDB on operating systems with a non-executable stack
3281 (Solaris, OpenBSD) now works.
3285 GDB has a new C++ demangler which does a better job on the mangled
3286 names generated by current versions of g++. It also runs faster, so
3287 with this and other changes gdb should now start faster on large C++
3290 * DWARF 2 Location Expressions
3292 GDB support for location expressions has been extended to support function
3293 arguments and frame bases. Older versions of GDB could crash when they
3296 * C++ nested types and namespaces
3298 GDB's support for nested types and namespaces in C++ has been
3299 improved, especially if you use the DWARF 2 debugging format. (This
3300 is the default for recent versions of GCC on most platforms.)
3301 Specifically, if you have a class "Inner" defined within a class or
3302 namespace "Outer", then GDB realizes that the class's name is
3303 "Outer::Inner", not simply "Inner". This should greatly reduce the
3304 frequency of complaints about not finding RTTI symbols. In addition,
3305 if you are stopped at inside of a function defined within a namespace,
3306 GDB modifies its name lookup accordingly.
3308 * New native configurations
3310 NetBSD/amd64 x86_64-*-netbsd*
3311 OpenBSD/amd64 x86_64-*-openbsd*
3312 OpenBSD/alpha alpha*-*-openbsd*
3313 OpenBSD/sparc sparc-*-openbsd*
3314 OpenBSD/sparc64 sparc64-*-openbsd*
3316 * New debugging protocols
3318 M32R with SDI protocol m32r-*-elf*
3320 * "set prompt-escape-char" command deleted.
3322 The command "set prompt-escape-char" has been deleted. This command,
3323 and its very obscure effet on GDB's prompt, was never documented,
3324 tested, nor mentioned in the NEWS file.
3326 * OBSOLETE configurations and files
3328 Configurations that have been declared obsolete in this release have
3329 been commented out. Unless there is activity to revive these
3330 configurations, the next release of GDB will have their sources
3331 permanently REMOVED.
3333 Sun 3, running SunOS 3 m68*-*-sunos3*
3334 Sun 3, running SunOS 4 m68*-*-sunos4*
3335 Sun 2, running SunOS 3 m68000-*-sunos3*
3336 Sun 2, running SunOS 4 m68000-*-sunos4*
3337 Motorola 680x0 running LynxOS m68*-*-lynxos*
3338 AT&T 3b1/Unix pc m68*-att-*
3339 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3340 decstation mips-dec-* mips-little-*
3341 riscos mips-*-riscos* mips-*-sysv*
3342 sonymips mips-sony-*
3343 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3345 * REMOVED configurations and files
3347 SGI Irix-4.x mips-sgi-irix4 or iris4
3348 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3349 Z8000 simulator z8k-zilog-none or z8ksim
3350 Matsushita MN10200 w/simulator mn10200-*-*
3351 H8/500 simulator h8500-hitachi-hms or h8500hms
3352 HP/PA running BSD hppa*-*-bsd*
3353 HP/PA running OSF/1 hppa*-*-osf*
3354 HP/PA Pro target hppa*-*-pro*
3355 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3356 386BSD i[3456]86-*-bsd*
3357 Sequent family i[3456]86-sequent-sysv4*
3358 i[3456]86-sequent-sysv*
3359 i[3456]86-sequent-bsd*
3360 SPARC running LynxOS sparc-*-lynxos*
3361 SPARC running SunOS 4 sparc-*-sunos4*
3362 Tsqware Sparclet sparclet-*-*
3363 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3365 *** Changes in GDB 6.0:
3369 Support for debugging the Objective-C programming language has been
3370 integrated into GDB.
3372 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3374 DWARF 2's Call Frame Information makes available compiler generated
3375 information that more exactly describes the program's run-time stack.
3376 By using this information, GDB is able to provide more robust stack
3379 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3380 have been updated to use a new backtrace mechanism which includes
3381 DWARF 2 CFI support.
3385 GDB's remote protocol has been extended to include support for hosted
3386 file I/O (where the remote target uses GDB's file system). See GDB's
3387 remote protocol documentation for details.
3389 * All targets using the new architecture framework.
3391 All of GDB's targets have been updated to use the new internal
3392 architecture framework. The way is now open for future GDB releases
3393 to include cross-architecture native debugging support (i386 on amd64,
3396 * GNU/Linux's Thread Local Storage (TLS)
3398 GDB now includes support for for the GNU/Linux implementation of
3399 per-thread variables.
3401 * GNU/Linux's Native POSIX Thread Library (NPTL)
3403 GDB's thread code has been updated to work with either the new
3404 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3406 * Separate debug info.
3408 GDB, in conjunction with BINUTILS, now supports a mechanism for
3409 automatically loading debug information from a separate file. Instead
3410 of shipping full debug and non-debug versions of system libraries,
3411 system integrators can now instead ship just the stripped libraries
3412 and optional debug files.
3414 * DWARF 2 Location Expressions
3416 DWARF 2 Location Expressions allow the compiler to more completely
3417 describe the location of variables (even in optimized code) to the
3420 GDB now includes preliminary support for location expressions (support
3421 for DW_OP_piece is still missing).
3425 A number of long standing bugs that caused GDB to die while starting a
3426 Java application have been fixed. GDB's Java support is now
3427 considered "useable".
3429 * GNU/Linux support for fork, vfork, and exec.
3431 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3432 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3435 * GDB supports logging output to a file
3437 There are two new commands, "set logging" and "show logging", which can be
3438 used to capture GDB's output to a file.
3440 * The meaning of "detach" has changed for gdbserver
3442 The "detach" command will now resume the application, as documented. To
3443 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3446 * d10v, m68hc11 `regs' command deprecated
3448 The `info registers' command has been updated so that it displays the
3449 registers using a format identical to the old `regs' command.
3453 A new command, "maint set profile on/off", has been added. This command can
3454 be used to enable or disable profiling while running GDB, to profile a
3455 session or a set of commands. In addition there is a new configure switch,
3456 "--enable-profiling", which will cause GDB to be compiled with profiling
3457 data, for more informative profiling results.
3459 * Default MI syntax changed to "mi2".
3461 The default MI (machine interface) syntax, enabled by the command line
3462 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3463 "mi1", can be enabled by specifying the option "-i=mi1".
3465 Support for the original "mi0" syntax (included in GDB 5.0) has been
3468 Fix for gdb/192: removed extraneous space when displaying frame level.
3469 Fix for gdb/672: update changelist is now output in mi list format.
3470 Fix for gdb/702: a -var-assign that updates the value now shows up
3471 in a subsequent -var-update.
3473 * New native configurations.
3475 FreeBSD/amd64 x86_64-*-freebsd*
3477 * Multi-arched targets.
3479 HP/PA HPUX11 hppa*-*-hpux*
3480 Renesas M32R/D w/simulator m32r-*-elf*
3482 * OBSOLETE configurations and files
3484 Configurations that have been declared obsolete in this release have
3485 been commented out. Unless there is activity to revive these
3486 configurations, the next release of GDB will have their sources
3487 permanently REMOVED.
3489 Z8000 simulator z8k-zilog-none or z8ksim
3490 Matsushita MN10200 w/simulator mn10200-*-*
3491 H8/500 simulator h8500-hitachi-hms or h8500hms
3492 HP/PA running BSD hppa*-*-bsd*
3493 HP/PA running OSF/1 hppa*-*-osf*
3494 HP/PA Pro target hppa*-*-pro*
3495 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3496 Sequent family i[3456]86-sequent-sysv4*
3497 i[3456]86-sequent-sysv*
3498 i[3456]86-sequent-bsd*
3499 Tsqware Sparclet sparclet-*-*
3500 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3502 * REMOVED configurations and files
3505 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3506 IBM AIX PS/2 i[3456]86-*-aix
3507 i386 running Mach 3.0 i[3456]86-*-mach3*
3508 i386 running Mach i[3456]86-*-mach*
3509 i386 running OSF/1 i[3456]86-*osf1mk*
3510 HP/Apollo 68k Family m68*-apollo*-sysv*,
3512 m68*-hp-bsd*, m68*-hp-hpux*
3513 Argonaut Risc Chip (ARC) arc-*-*
3514 Mitsubishi D30V d30v-*-*
3515 Fujitsu FR30 fr30-*-elf*
3516 OS/9000 i[34]86-*-os9k
3517 I960 with MON960 i960-*-coff
3519 * MIPS $fp behavior changed
3521 The convenience variable $fp, for the MIPS, now consistently returns
3522 the address of the current frame's base. Previously, depending on the
3523 context, $fp could refer to either $sp or the current frame's base
3524 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3525 The GNU Source-Level Debugger''.
3527 *** Changes in GDB 5.3:
3529 * GNU/Linux shared library multi-threaded performance improved.
3531 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3532 `/proc', in preference to `ptrace' for memory reads. This may result
3533 in an improvement in the start-up time of multi-threaded, shared
3534 library applications when run under GDB. One GDB user writes: ``loads
3535 shared libs like mad''.
3537 * ``gdbserver'' now supports multi-threaded applications on some targets
3539 Support for debugging multi-threaded applications which use
3540 the GNU/Linux LinuxThreads package has been added for
3541 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3542 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3544 * GDB now supports C/C++ preprocessor macros.
3546 GDB now expands preprocessor macro invocations in C/C++ expressions,
3547 and provides various commands for showing macro definitions and how
3550 The new command `macro expand EXPRESSION' expands any macro
3551 invocations in expression, and shows the result.
3553 The new command `show macro MACRO-NAME' shows the definition of the
3554 macro named MACRO-NAME, and where it was defined.
3556 Most compilers don't include information about macros in the debugging
3557 information by default. In GCC 3.1, for example, you need to compile
3558 your program with the options `-gdwarf-2 -g3'. If the macro
3559 information is present in the executable, GDB will read it.
3561 * Multi-arched targets.
3563 DEC Alpha (partial) alpha*-*-*
3564 DEC VAX (partial) vax-*-*
3566 National Semiconductor NS32000 (partial) ns32k-*-*
3567 Motorola 68000 (partial) m68k-*-*
3568 Motorola MCORE mcore-*-*
3572 Fujitsu FRV architecture added by Red Hat frv*-*-*
3575 * New native configurations
3577 Alpha NetBSD alpha*-*-netbsd*
3578 SH NetBSD sh*-*-netbsdelf*
3579 MIPS NetBSD mips*-*-netbsd*
3580 UltraSPARC NetBSD sparc64-*-netbsd*
3582 * OBSOLETE configurations and files
3584 Configurations that have been declared obsolete in this release have
3585 been commented out. Unless there is activity to revive these
3586 configurations, the next release of GDB will have their sources
3587 permanently REMOVED.
3589 Mitsubishi D30V d30v-*-*
3590 OS/9000 i[34]86-*-os9k
3591 IBM AIX PS/2 i[3456]86-*-aix
3592 Fujitsu FR30 fr30-*-elf*
3593 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3594 Argonaut Risc Chip (ARC) arc-*-*
3595 i386 running Mach 3.0 i[3456]86-*-mach3*
3596 i386 running Mach i[3456]86-*-mach*
3597 i386 running OSF/1 i[3456]86-*osf1mk*
3598 HP/Apollo 68k Family m68*-apollo*-sysv*,
3600 m68*-hp-bsd*, m68*-hp-hpux*
3601 I960 with MON960 i960-*-coff
3603 * OBSOLETE languages
3605 CHILL, a Pascal like language used by telecommunications companies.
3607 * REMOVED configurations and files
3609 AMD 29k family via UDI a29k-amd-udi, udi29k
3610 A29K VxWorks a29k-*-vxworks
3611 AMD 29000 embedded, using EBMON a29k-none-none
3612 AMD 29000 embedded with COFF a29k-none-coff
3613 AMD 29000 embedded with a.out a29k-none-aout
3615 testsuite/gdb.hp/gdb.threads-hp/ directory
3617 * New command "set max-user-call-depth <nnn>"
3619 This command allows the user to limit the call depth of user-defined
3620 commands. The default is 1024.
3622 * Changes in FreeBSD/i386 native debugging.
3624 Support for the "generate-core-file" has been added.
3626 * New commands "dump", "append", and "restore".
3628 These commands allow data to be copied from target memory
3629 to a bfd-format or binary file (dump and append), and back
3630 from a file into memory (restore).
3632 * Improved "next/step" support on multi-processor Alpha Tru64.
3634 The previous single-step mechanism could cause unpredictable problems,
3635 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3636 of a software single-step mechanism prevents this.
3638 *** Changes in GDB 5.2.1:
3646 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3647 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3648 Fix, by Joel Brobecker imported from mainline.
3650 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3651 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3652 Fix, by Fred Fish, imported from mainline.
3654 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3655 Surprisingly enough, it works now.
3656 By Michal Ludvig, imported from mainline.
3658 i386 hardware watchpoint support:
3659 avoid misses on second run for some targets.
3660 By Pierre Muller, imported from mainline.
3662 *** Changes in GDB 5.2:
3664 * New command "set trust-readonly-sections on[off]".
3666 This command is a hint that tells gdb that read-only sections
3667 really are read-only (ie. that their contents will not change).
3668 In this mode, gdb will go to the object file rather than the
3669 target to read memory from read-only sections (such as ".text").
3670 This can be a significant performance improvement on some
3671 (notably embedded) targets.
3673 * New command "generate-core-file" (or "gcore").
3675 This new gdb command allows the user to drop a core file of the child
3676 process state at any time. So far it's been implemented only for
3677 GNU/Linux and Solaris, but should be relatively easily ported to other
3678 hosts. Argument is core file name (defaults to core.<pid>).
3680 * New command line option
3682 GDB now accepts --pid or -p followed by a process id.
3684 * Change in command line behavior -- corefiles vs. process ids.
3686 There is a subtle behavior in the way in which GDB handles
3687 command line arguments. The first non-flag argument is always
3688 a program to debug, but the second non-flag argument may either
3689 be a corefile or a process id. Previously, GDB would attempt to
3690 open the second argument as a corefile, and if that failed, would
3691 issue a superfluous error message and then attempt to attach it as
3692 a process. Now, if the second argument begins with a non-digit,
3693 it will be treated as a corefile. If it begins with a digit,
3694 GDB will attempt to attach it as a process, and if no such process
3695 is found, will then attempt to open it as a corefile.
3697 * Changes in ARM configurations.
3699 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3700 configuration is fully multi-arch.
3702 * New native configurations
3704 ARM NetBSD arm*-*-netbsd*
3705 x86 OpenBSD i[3456]86-*-openbsd*
3706 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3707 Sparc64 running FreeBSD sparc64-*-freebsd*
3711 Sanyo XStormy16 xstormy16-elf
3713 * OBSOLETE configurations and files
3715 Configurations that have been declared obsolete in this release have
3716 been commented out. Unless there is activity to revive these
3717 configurations, the next release of GDB will have their sources
3718 permanently REMOVED.
3720 AMD 29k family via UDI a29k-amd-udi, udi29k
3721 A29K VxWorks a29k-*-vxworks
3722 AMD 29000 embedded, using EBMON a29k-none-none
3723 AMD 29000 embedded with COFF a29k-none-coff
3724 AMD 29000 embedded with a.out a29k-none-aout
3726 testsuite/gdb.hp/gdb.threads-hp/ directory
3728 * REMOVED configurations and files
3730 TI TMS320C80 tic80-*-*
3732 PowerPC Solaris powerpcle-*-solaris*
3733 PowerPC Windows NT powerpcle-*-cygwin32
3734 PowerPC Netware powerpc-*-netware*
3735 Harris/CXUX m88k m88*-harris-cxux*
3736 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3737 ns32k-utek-sysv* ns32k-utek-*
3738 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3739 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3740 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3741 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3742 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3744 * Changes to command line processing
3746 The new `--args' feature can be used to specify command-line arguments
3747 for the inferior from gdb's command line.
3749 * Changes to key bindings
3751 There is a new `operate-and-get-next' function bound to `C-o'.
3753 *** Changes in GDB 5.1.1
3755 Fix compile problem on DJGPP.
3757 Fix a problem with floating-point registers on the i386 being
3760 Fix to stop GDB crashing on .debug_str debug info.
3762 Numerous documentation fixes.
3764 Numerous testsuite fixes.
3766 *** Changes in GDB 5.1:
3768 * New native configurations
3770 Alpha FreeBSD alpha*-*-freebsd*
3771 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3772 MIPS GNU/Linux mips*-*-linux*
3773 MIPS SGI Irix 6.x mips*-sgi-irix6*
3774 ia64 AIX ia64-*-aix*
3775 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3779 Motorola 68HC11 and 68HC12 m68hc11-elf
3781 UltraSparc running GNU/Linux sparc64-*-linux*
3783 * OBSOLETE configurations and files
3785 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3786 Harris/CXUX m88k m88*-harris-cxux*
3787 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3788 ns32k-utek-sysv* ns32k-utek-*
3789 TI TMS320C80 tic80-*-*
3791 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3792 PowerPC Solaris powerpcle-*-solaris*
3793 PowerPC Windows NT powerpcle-*-cygwin32
3794 PowerPC Netware powerpc-*-netware*
3795 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3796 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3797 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3798 Apple Macintosh (MPW) host N/A
3800 stuff.c (Program to stuff files into a specially prepared space in kdb)
3801 kdb-start.c (Main loop for the standalone kernel debugger)
3803 Configurations that have been declared obsolete in this release have
3804 been commented out. Unless there is activity to revive these
3805 configurations, the next release of GDB will have their sources
3806 permanently REMOVED.
3808 * REMOVED configurations and files
3810 Altos 3068 m68*-altos-*
3811 Convex c1-*-*, c2-*-*
3813 ARM RISCix arm-*-* (as host)
3817 * GDB has been converted to ISO C.
3819 GDB's source code has been converted to ISO C. In particular, the
3820 sources are fully protoized, and rely on standard headers being
3825 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3827 * The MI enabled by default.
3829 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3830 revised and enabled by default. Packages which use GDB as a debugging
3831 engine behind a UI or another front end are encouraged to switch to
3832 using the GDB/MI interface, instead of the old annotations interface
3833 which is now deprecated.
3835 * Support for debugging Pascal programs.
3837 GDB now includes support for debugging Pascal programs. The following
3838 main features are supported:
3840 - Pascal-specific data types such as sets;
3842 - automatic recognition of Pascal sources based on file-name
3845 - Pascal-style display of data types, variables, and functions;
3847 - a Pascal expression parser.
3849 However, some important features are not yet supported.
3851 - Pascal string operations are not supported at all;
3853 - there are some problems with boolean types;
3855 - Pascal type hexadecimal constants are not supported
3856 because they conflict with the internal variables format;
3858 - support for Pascal objects and classes is not full yet;
3860 - unlike Pascal, GDB is case-sensitive for symbol names.
3862 * Changes in completion.
3864 Commands such as `shell', `run' and `set args', which pass arguments
3865 to inferior programs, now complete on file names, similar to what
3866 users expect at the shell prompt.
3868 Commands which accept locations, such as `disassemble', `print',
3869 `breakpoint', `until', etc. now complete on filenames as well as
3870 program symbols. Thus, if you type "break foob TAB", and the source
3871 files linked into the programs include `foobar.c', that file name will
3872 be one of the candidates for completion. However, file names are not
3873 considered for completion after you typed a colon that delimits a file
3874 name from a name of a function in that file, as in "break foo.c:bar".
3876 `set demangle-style' completes on available demangling styles.
3878 * New platform-independent commands:
3880 It is now possible to define a post-hook for a command as well as a
3881 hook that runs before the command. For more details, see the
3882 documentation of `hookpost' in the GDB manual.
3884 * Changes in GNU/Linux native debugging.
3886 Support for debugging multi-threaded programs has been completely
3887 revised for all platforms except m68k and sparc. You can now debug as
3888 many threads as your system allows you to have.
3890 Attach/detach is supported for multi-threaded programs.
3892 Support for SSE registers was added for x86. This doesn't work for
3893 multi-threaded programs though.
3895 * Changes in MIPS configurations.
3897 Multi-arch support is enabled for all MIPS configurations.
3899 GDB can now be built as native debugger on SGI Irix 6.x systems for
3900 debugging n32 executables. (Debugging 64-bit executables is not yet
3903 * Unified support for hardware watchpoints in all x86 configurations.
3905 Most (if not all) native x86 configurations support hardware-assisted
3906 breakpoints and watchpoints in a unified manner. This support
3907 implements debug register sharing between watchpoints, which allows to
3908 put a virtually infinite number of watchpoints on the same address,
3909 and also supports watching regions up to 16 bytes with several debug
3912 The new maintenance command `maintenance show-debug-regs' toggles
3913 debugging print-outs in functions that insert, remove, and test
3914 watchpoints and hardware breakpoints.
3916 * Changes in the DJGPP native configuration.
3918 New command ``info dos sysinfo'' displays assorted information about
3919 the CPU, OS, memory, and DPMI server.
3921 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3922 display information about segment descriptors stored in GDT, LDT, and
3925 New commands ``info dos pde'' and ``info dos pte'' display entries
3926 from Page Directory and Page Tables (for now works with CWSDPMI only).
3927 New command ``info dos address-pte'' displays the Page Table entry for
3928 a given linear address.
3930 GDB can now pass command lines longer than 126 characters to the
3931 program being debugged (requires an update to the libdbg.a library
3932 which is part of the DJGPP development kit).
3934 DWARF2 debug info is now supported.
3936 It is now possible to `step' and `next' through calls to `longjmp'.
3938 * Changes in documentation.
3940 All GDB documentation was converted to GFDL, the GNU Free
3941 Documentation License.
3943 Tracepoints-related commands are now fully documented in the GDB
3946 TUI, the Text-mode User Interface, is now documented in the manual.
3948 Tracepoints-related commands are now fully documented in the GDB
3951 The "GDB Internals" manual now has an index. It also includes
3952 documentation of `ui_out' functions, GDB coding standards, x86
3953 hardware watchpoints, and memory region attributes.
3955 * GDB's version number moved to ``version.in''
3957 The Makefile variable VERSION has been replaced by the file
3958 ``version.in''. People creating GDB distributions should update the
3959 contents of this file.
3963 GUD support is now a standard part of the EMACS distribution.
3965 *** Changes in GDB 5.0:
3967 * Improved support for debugging FP programs on x86 targets
3969 Unified and much-improved support for debugging floating-point
3970 programs on all x86 targets. In particular, ``info float'' now
3971 displays the FP registers in the same format on all x86 targets, with
3972 greater level of detail.
3974 * Improvements and bugfixes in hardware-assisted watchpoints
3976 It is now possible to watch array elements, struct members, and
3977 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3978 on x86 targets no longer erroneously trigger when the address is
3981 * Improvements in the native DJGPP version of GDB
3983 The distribution now includes all the scripts and auxiliary files
3984 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3985 machines ``out of the box''.
3987 The DJGPP version can now debug programs that use signals. It is
3988 possible to catch signals that happened in the debuggee, deliver
3989 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3990 would kill the program being debugged.) Programs that hook hardware
3991 interrupts (keyboard, timer, etc.) can also be debugged.
3993 It is now possible to debug DJGPP programs that redirect their
3994 standard handles or switch them to raw (as opposed to cooked) mode, or
3995 even close them. The command ``run < foo > bar'' works as expected,
3996 and ``info terminal'' reports useful information about the debuggee's
3997 terminal, including raw/cooked mode, redirection, etc.
3999 The DJGPP version now uses termios functions for console I/O, which
4000 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4003 DOS-style file names with drive letters are now fully supported by
4006 It is now possible to debug DJGPP programs that switch their working
4007 directory. It is also possible to rerun the debuggee any number of
4008 times without restarting GDB; thus, you can use the same setup,
4009 breakpoints, etc. for many debugging sessions.
4011 * New native configurations
4013 ARM GNU/Linux arm*-*-linux*
4014 PowerPC GNU/Linux powerpc-*-linux*
4018 Motorola MCore mcore-*-*
4019 x86 VxWorks i[3456]86-*-vxworks*
4020 PowerPC VxWorks powerpc-*-vxworks*
4021 TI TMS320C80 tic80-*-*
4023 * OBSOLETE configurations
4025 Altos 3068 m68*-altos-*
4026 Convex c1-*-*, c2-*-*
4028 ARM RISCix arm-*-* (as host)
4031 Configurations that have been declared obsolete will be commented out,
4032 but the code will be left in place. If there is no activity to revive
4033 these configurations before the next release of GDB, the sources will
4034 be permanently REMOVED.
4036 * Gould support removed
4038 Support for the Gould PowerNode and NP1 has been removed.
4040 * New features for SVR4
4042 On SVR4 native platforms (such as Solaris), if you attach to a process
4043 without first loading a symbol file, GDB will now attempt to locate and
4044 load symbols from the running process's executable file.
4046 * Many C++ enhancements
4048 C++ support has been greatly improved. Overload resolution now works properly
4049 in almost all cases. RTTI support is on the way.
4051 * Remote targets can connect to a sub-program
4053 A popen(3) style serial-device has been added. This device starts a
4054 sub-process (such as a stand-alone simulator) and then communicates
4055 with that. The sub-program to run is specified using the syntax
4056 ``|<program> <args>'' vis:
4058 (gdb) set remotedebug 1
4059 (gdb) target extended-remote |mn10300-elf-sim program-args
4061 * MIPS 64 remote protocol
4063 A long standing bug in the mips64 remote protocol where by GDB
4064 expected certain 32 bit registers (ex SR) to be transfered as 32
4065 instead of 64 bits has been fixed.
4067 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4068 added to provide backward compatibility with older versions of GDB.
4070 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4072 The command ``set remotebinarydownload'' command has been replaced by
4073 ``set remote X-packet''. Other commands in ``set remote'' family
4074 include ``set remote P-packet''.
4076 * Breakpoint commands accept ranges.
4078 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4079 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4080 ``tracepoint passcount'' also accepts a range of tracepoints.
4082 * ``apropos'' command added.
4084 The ``apropos'' command searches through command names and
4085 documentation strings, printing out matches, making it much easier to
4086 try to find a command that does what you are looking for.
4090 A new machine oriented interface (MI) has been added to GDB. This
4091 interface is designed for debug environments running GDB as a separate
4092 process. This is part of the long term libGDB project. See the
4093 "GDB/MI" chapter of the GDB manual for further information. It can be
4094 enabled by configuring with:
4096 .../configure --enable-gdbmi
4098 *** Changes in GDB-4.18:
4100 * New native configurations
4102 HP-UX 10.20 hppa*-*-hpux10.20
4103 HP-UX 11.x hppa*-*-hpux11.0*
4104 M68K GNU/Linux m68*-*-linux*
4108 Fujitsu FR30 fr30-*-elf*
4109 Intel StrongARM strongarm-*-*
4110 Mitsubishi D30V d30v-*-*
4112 * OBSOLETE configurations
4114 Gould PowerNode, NP1 np1-*-*, pn-*-*
4116 Configurations that have been declared obsolete will be commented out,
4117 but the code will be left in place. If there is no activity to revive
4118 these configurations before the next release of GDB, the sources will
4119 be permanently REMOVED.
4123 As a compatibility experiment, GDB's source files buildsym.h and
4124 buildsym.c have been converted to pure standard C, no longer
4125 containing any K&R compatibility code. We believe that all systems in
4126 use today either come with a standard C compiler, or have a GCC port
4127 available. If this is not true, please report the affected
4128 configuration to bug-gdb@gnu.org immediately. See the README file for
4129 information about getting a standard C compiler if you don't have one
4134 GDB now uses readline 2.2.
4136 * set extension-language
4138 You can now control the mapping between filename extensions and source
4139 languages by using the `set extension-language' command. For instance,
4140 you can ask GDB to treat .c files as C++ by saying
4141 set extension-language .c c++
4142 The command `info extensions' lists all of the recognized extensions
4143 and their associated languages.
4145 * Setting processor type for PowerPC and RS/6000
4147 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4148 you can use the `set processor' command to specify what variant of the
4149 PowerPC family you are debugging. The command
4153 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4154 following PowerPC and RS6000 variants:
4156 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4157 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4159 403GC IBM PowerPC 403GC
4160 505 Motorola PowerPC 505
4161 860 Motorola PowerPC 860 or 850
4162 601 Motorola PowerPC 601
4163 602 Motorola PowerPC 602
4164 603 Motorola/IBM PowerPC 603 or 603e
4165 604 Motorola PowerPC 604 or 604e
4166 750 Motorola/IBM PowerPC 750 or 750
4168 At the moment, this command just tells GDB what to name the
4169 special-purpose processor registers. Since almost all the affected
4170 registers are inaccessible to user-level programs, this command is
4171 only useful for remote debugging in its present form.
4175 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4176 more extensive support for HP-UX. Added features include shared
4177 library support, kernel threads and hardware watchpoints for 11.00,
4178 support for HP's ANSI C and C++ compilers, and a compatibility mode
4179 for xdb and dbx commands.
4183 HP's donation includes the new concept of catchpoints, which is a
4184 generalization of the old catch command. On HP-UX, it is now possible
4185 to catch exec, fork, and vfork, as well as library loading.
4187 This means that the existing catch command has changed; its first
4188 argument now specifies the type of catch to be set up. See the
4189 output of "help catch" for a list of catchpoint types.
4191 * Debugging across forks
4193 On HP-UX, you can choose which process to debug when a fork() happens
4198 HP has donated a curses-based terminal user interface (TUI). To get
4199 it, build with --enable-tui. Although this can be enabled for any
4200 configuration, at present it only works for native HP debugging.
4202 * GDB remote protocol additions
4204 A new protocol packet 'X' that writes binary data is now available.
4205 Default behavior is to try 'X', then drop back to 'M' if the stub
4206 fails to respond. The settable variable `remotebinarydownload'
4207 allows explicit control over the use of 'X'.
4209 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4210 full 64-bit address. The command
4212 set remoteaddresssize 32
4214 can be used to revert to the old behaviour. For existing remote stubs
4215 the change should not be noticed, as the additional address information
4218 In order to assist in debugging stubs, you may use the maintenance
4219 command `packet' to send any text string to the stub. For instance,
4221 maint packet heythere
4223 sends the packet "$heythere#<checksum>". Note that it is very easy to
4224 disrupt a debugging session by sending the wrong packet at the wrong
4227 The compare-sections command allows you to compare section data on the
4228 target to what is in the executable file without uploading or
4229 downloading, by comparing CRC checksums.
4231 * Tracing can collect general expressions
4233 You may now collect general expressions at tracepoints. This requires
4234 further additions to the target-side stub; see tracepoint.c and
4235 doc/agentexpr.texi for further details.
4237 * mask-address variable for Mips
4239 For Mips targets, you may control the zeroing of the upper 32 bits of
4240 a 64-bit address by entering `set mask-address on'. This is mainly
4241 of interest to users of embedded R4xxx and R5xxx processors.
4243 * Higher serial baud rates
4245 GDB's serial code now allows you to specify baud rates 57600, 115200,
4246 230400, and 460800 baud. (Note that your host system may not be able
4247 to achieve all of these rates.)
4251 The i960 configuration now includes an initial implementation of a
4252 builtin simulator, contributed by Jim Wilson.
4255 *** Changes in GDB-4.17:
4257 * New native configurations
4259 Alpha GNU/Linux alpha*-*-linux*
4260 Unixware 2.x i[3456]86-unixware2*
4261 Irix 6.x mips*-sgi-irix6*
4262 PowerPC GNU/Linux powerpc-*-linux*
4263 PowerPC Solaris powerpcle-*-solaris*
4264 Sparc GNU/Linux sparc-*-linux*
4265 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4269 Argonaut Risc Chip (ARC) arc-*-*
4270 Hitachi H8/300S h8300*-*-*
4271 Matsushita MN10200 w/simulator mn10200-*-*
4272 Matsushita MN10300 w/simulator mn10300-*-*
4273 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4274 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4275 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4276 Mitsubishi D10V w/simulator d10v-*-*
4277 Mitsubishi M32R/D w/simulator m32r-*-elf*
4278 Tsqware Sparclet sparclet-*-*
4279 NEC V850 w/simulator v850-*-*
4281 * New debugging protocols
4283 ARM with RDI protocol arm*-*-*
4284 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4285 DDB and LSI variants of PMON protocol mips*-*-*
4286 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4287 PowerPC with SDS protocol powerpc{,le}-*-eabi
4288 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4292 All configurations can now understand and use the DWARF 2 debugging
4293 format. The choice is automatic, if the symbol file contains DWARF 2
4298 GDB now includes basic Java language support. This support is
4299 only useful with Java compilers that produce native machine code.
4301 * solib-absolute-prefix and solib-search-path
4303 For SunOS and SVR4 shared libraries, you may now set the prefix for
4304 loading absolute shared library symbol files, and the search path for
4305 locating non-absolute shared library symbol files.
4307 * Live range splitting
4309 GDB can now effectively debug code for which GCC has performed live
4310 range splitting as part of its optimization. See gdb/doc/LRS for
4311 more details on the expected format of the stabs information.
4315 GDB's support for the GNU Hurd, including thread debugging, has been
4316 updated to work with current versions of the Hurd.
4320 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4321 instruction set. ARM GDB automatically detects when Thumb
4322 instructions are in use, and adjusts disassembly and backtracing
4327 GDB's MIPS target configurations now handle the MIP16 16-bit
4332 GDB now includes support for overlays; if an executable has been
4333 linked such that multiple sections are based at the same address, GDB
4334 will decide which section to use for symbolic info. You can choose to
4335 control the decision manually, using overlay commands, or implement
4336 additional target-side support and use "overlay load-target" to bring
4337 in the overlay mapping. Do "help overlay" for more detail.
4341 The command "info symbol <address>" displays information about
4342 the symbol at the specified address.
4346 The standard remote protocol now includes an extension that allows
4347 asynchronous collection and display of trace data. This requires
4348 extensive support in the target-side debugging stub. Tracing mode
4349 includes a new interaction mode in GDB and new commands: see the
4350 file tracepoint.c for more details.
4354 Configurations for embedded MIPS now include a simulator contributed
4355 by Cygnus Solutions. The simulator supports the instruction sets
4356 of most MIPS variants.
4360 Sparc configurations may now include the ERC32 simulator contributed
4361 by the European Space Agency. The simulator is not built into
4362 Sparc targets by default; configure with --enable-sim to include it.
4366 For target configurations that may include multiple variants of a
4367 basic architecture (such as MIPS and SH), you may now set the
4368 architecture explicitly. "set arch" sets, "info arch" lists
4369 the possible architectures.
4371 *** Changes in GDB-4.16:
4373 * New native configurations
4375 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4376 M68K NetBSD m68k-*-netbsd*
4377 PowerPC AIX 4.x powerpc-*-aix*
4378 PowerPC MacOS powerpc-*-macos*
4379 PowerPC Windows NT powerpcle-*-cygwin32
4380 RS/6000 AIX 4.x rs6000-*-aix4*
4384 ARM with RDP protocol arm-*-*
4385 I960 with MON960 i960-*-coff
4386 MIPS VxWorks mips*-*-vxworks*
4387 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4388 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4390 Matra Sparclet sparclet-*-*
4394 The powerpc-eabi configuration now includes the PSIM simulator,
4395 contributed by Andrew Cagney, with assistance from Mike Meissner.
4396 PSIM is a very elaborate model of the PowerPC, including not only
4397 basic instruction set execution, but also details of execution unit
4398 performance and I/O hardware. See sim/ppc/README for more details.
4402 GDB now works with Solaris 2.5.
4404 * Windows 95/NT native
4406 GDB will now work as a native debugger on Windows 95 and Windows NT.
4407 To build it from source, you must use the "gnu-win32" environment,
4408 which uses a DLL to emulate enough of Unix to run the GNU tools.
4409 Further information, binaries, and sources are available at
4410 ftp.cygnus.com, under pub/gnu-win32.
4412 * dont-repeat command
4414 If a user-defined command includes the command `dont-repeat', then the
4415 command will not be repeated if the user just types return. This is
4416 useful if the command is time-consuming to run, so that accidental
4417 extra keystrokes don't run the same command many times.
4419 * Send break instead of ^C
4421 The standard remote protocol now includes an option to send a break
4422 rather than a ^C to the target in order to interrupt it. By default,
4423 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4425 * Remote protocol timeout
4427 The standard remote protocol includes a new variable `remotetimeout'
4428 that allows you to set the number of seconds before GDB gives up trying
4429 to read from the target. The default value is 2.
4431 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4433 By default GDB will automatically keep track of objects as they are
4434 loaded and unloaded by the dynamic linker. By using the command `set
4435 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4436 when shared library events occur, thus allowing you to set breakpoints
4437 in shared libraries which are explicitly loaded by the inferior.
4439 Note this feature does not work on hpux8. On hpux9 you must link
4440 /usr/lib/end.o into your program. This feature should work
4441 automatically on hpux10.
4443 * Irix 5.x hardware watchpoint support
4445 Irix 5 configurations now support the use of hardware watchpoints.
4447 * Mips protocol "SYN garbage limit"
4449 When debugging a Mips target using the `target mips' protocol, you
4450 may set the number of characters that GDB will ignore by setting
4451 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4452 every character. The default value is 1050.
4454 * Recording and replaying remote debug sessions
4456 If you set `remotelogfile' to the name of a file, gdb will write to it
4457 a recording of a remote debug session. This recording may then be
4458 replayed back to gdb using "gdbreplay". See gdbserver/README for
4459 details. This is useful when you have a problem with GDB while doing
4460 remote debugging; you can make a recording of the session and send it
4461 to someone else, who can then recreate the problem.
4463 * Speedups for remote debugging
4465 GDB includes speedups for downloading and stepping MIPS systems using
4466 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4467 and more efficient S-record downloading.
4469 * Memory use reductions and statistics collection
4471 GDB now uses less memory and reports statistics about memory usage.
4472 Try the `maint print statistics' command, for example.
4474 *** Changes in GDB-4.15:
4476 * Psymtabs for XCOFF
4478 The symbol reader for AIX GDB now uses partial symbol tables. This
4479 can greatly improve startup time, especially for large executables.
4481 * Remote targets use caching
4483 Remote targets now use a data cache to speed up communication with the
4484 remote side. The data cache could lead to incorrect results because
4485 it doesn't know about volatile variables, thus making it impossible to
4486 debug targets which use memory mapped I/O devices. `set remotecache
4487 off' turns the the data cache off.
4489 * Remote targets may have threads
4491 The standard remote protocol now includes support for multiple threads
4492 in the target system, using new protocol commands 'H' and 'T'. See
4493 gdb/remote.c for details.
4497 If GDB is configured with `--enable-netrom', then it will include
4498 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4499 acts as though it is a bank of ROM on the target board, but you can
4500 write into it over the network. GDB's support consists only of
4501 support for fast loading into the emulated ROM; to debug, you must use
4502 another protocol, such as standard remote protocol. The usual
4503 sequence is something like
4505 target nrom <netrom-hostname>
4507 target remote <netrom-hostname>:1235
4511 GDB now includes support for the Apple Macintosh, as a host only. It
4512 may be run as either an MPW tool or as a standalone application, and
4513 it can debug through the serial port. All the usual GDB commands are
4514 available, but to the target command, you must supply "serial" as the
4515 device type instead of "/dev/ttyXX". See mpw-README in the main
4516 directory for more information on how to build. The MPW configuration
4517 scripts */mpw-config.in support only a few targets, and only the
4518 mips-idt-ecoff target has been tested.
4522 GDB configuration now uses autoconf. This is not user-visible,
4523 but does simplify configuration and building.
4527 GDB now supports hpux10.
4529 *** Changes in GDB-4.14:
4531 * New native configurations
4533 x86 FreeBSD i[345]86-*-freebsd
4534 x86 NetBSD i[345]86-*-netbsd
4535 NS32k NetBSD ns32k-*-netbsd
4536 Sparc NetBSD sparc-*-netbsd
4540 A29K VxWorks a29k-*-vxworks
4541 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4542 CPU32 EST-300 emulator m68*-*-est*
4543 PowerPC ELF powerpc-*-elf
4546 * Alpha OSF/1 support for procfs
4548 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4549 possible to attach to running processes. As the mounting of the /proc
4550 filesystem is optional on the Alpha, GDB automatically determines
4551 the availability of /proc during startup. This can lead to problems
4552 if /proc is unmounted after GDB has been started.
4554 * Arguments to user-defined commands
4556 User commands may accept up to 10 arguments separated by whitespace.
4557 Arguments are accessed within the user command via $arg0..$arg9. A
4560 print $arg0 + $arg1 + $arg2
4562 To execute the command use:
4565 Defines the command "adder" which prints the sum of its three arguments.
4566 Note the arguments are text substitutions, so they may reference variables,
4567 use complex expressions, or even perform inferior function calls.
4569 * New `if' and `while' commands
4571 This makes it possible to write more sophisticated user-defined
4572 commands. Both commands take a single argument, which is the
4573 expression to evaluate, and must be followed by the commands to
4574 execute, one per line, if the expression is nonzero, the list being
4575 terminated by the word `end'. The `if' command list may include an
4576 `else' word, which causes the following commands to be executed only
4577 if the expression is zero.
4579 * Fortran source language mode
4581 GDB now includes partial support for Fortran 77. It will recognize
4582 Fortran programs and can evaluate a subset of Fortran expressions, but
4583 variables and functions may not be handled correctly. GDB will work
4584 with G77, but does not yet know much about symbols emitted by other
4587 * Better HPUX support
4589 Most debugging facilities now work on dynamic executables for HPPAs
4590 running hpux9 or later. You can attach to running dynamically linked
4591 processes, but by default the dynamic libraries will be read-only, so
4592 for instance you won't be able to put breakpoints in them. To change
4593 that behavior do the following before running the program:
4599 This will cause the libraries to be mapped private and read-write.
4600 To revert to the normal behavior, do this:
4606 You cannot set breakpoints or examine data in the library until after
4607 the library is loaded if the function/data symbols do not have
4610 GDB can now also read debug symbols produced by the HP C compiler on
4611 HPPAs (sorry, no C++, Fortran or 68k support).
4613 * Target byte order now dynamically selectable
4615 You can choose which byte order to use with a target system, via the
4616 commands "set endian big" and "set endian little", and you can see the
4617 current setting by using "show endian". You can also give the command
4618 "set endian auto", in which case GDB will use the byte order
4619 associated with the executable. Currently, only embedded MIPS
4620 configurations support dynamic selection of target byte order.
4622 * New DOS host serial code
4624 This version uses DPMI interrupts to handle buffered I/O, so you
4625 no longer need to run asynctsr when debugging boards connected to
4628 *** Changes in GDB-4.13:
4630 * New "complete" command
4632 This lists all the possible completions for the rest of the line, if it
4633 were to be given as a command itself. This is intended for use by emacs.
4635 * Trailing space optional in prompt
4637 "set prompt" no longer adds a space for you after the prompt you set. This
4638 allows you to set a prompt which ends in a space or one that does not.
4640 * Breakpoint hit counts
4642 "info break" now displays a count of the number of times the breakpoint
4643 has been hit. This is especially useful in conjunction with "ignore"; you
4644 can ignore a large number of breakpoint hits, look at the breakpoint info
4645 to see how many times the breakpoint was hit, then run again, ignoring one
4646 less than that number, and this will get you quickly to the last hit of
4649 * Ability to stop printing at NULL character
4651 "set print null-stop" will cause GDB to stop printing the characters of
4652 an array when the first NULL is encountered. This is useful when large
4653 arrays actually contain only short strings.
4655 * Shared library breakpoints
4657 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4658 breakpoints in shared libraries before the executable is run.
4660 * Hardware watchpoints
4662 There is a new hardware breakpoint for the watch command for sparclite
4663 targets. See gdb/sparclite/hw_breakpoint.note.
4665 Hardware watchpoints are also now supported under GNU/Linux.
4669 Annotations have been added. These are for use with graphical interfaces,
4670 and are still experimental. Currently only gdba.el uses these.
4672 * Improved Irix 5 support
4674 GDB now works properly with Irix 5.2.
4676 * Improved HPPA support
4678 GDB now works properly with the latest GCC and GAS.
4680 * New native configurations
4682 Sequent PTX4 i[34]86-sequent-ptx4
4683 HPPA running OSF/1 hppa*-*-osf*
4684 Atari TT running SVR4 m68*-*-sysv4*
4685 RS/6000 LynxOS rs6000-*-lynxos*
4689 OS/9000 i[34]86-*-os9k
4690 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4693 * Hitachi SH7000 and E7000-PC ICE support
4695 There is now support for communicating with the Hitachi E7000-PC ICE.
4696 This is available automatically when GDB is configured for the SH.
4700 As usual, a variety of small fixes and improvements, both generic
4701 and configuration-specific. See the ChangeLog for more detail.
4703 *** Changes in GDB-4.12:
4705 * Irix 5 is now supported
4709 GDB-4.12 on the HPPA has a number of changes which make it unable
4710 to debug the output from the currently released versions of GCC and
4711 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4712 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4713 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4716 *** Changes in GDB-4.11:
4718 * User visible changes:
4722 The "set remotedebug" option is now consistent between the mips remote
4723 target, remote targets using the gdb-specific protocol, UDI (AMD's
4724 debug protocol for the 29k) and the 88k bug monitor. It is now an
4725 integer specifying a debug level (normally 0 or 1, but 2 means more
4726 debugging info for the mips target).
4728 * DEC Alpha native support
4730 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4731 debug info, but GDB works fairly well with the DEC compiler and should
4732 work with a future GCC release. See the README file for a few
4733 Alpha-specific notes.
4735 * Preliminary thread implementation
4737 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4739 * LynxOS native and target support for 386
4741 This release has been hosted on LynxOS 2.2, and also can be configured
4742 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4745 * Improvements in C++ mangling/demangling.
4747 This release has much better g++ debugging, specifically in name
4748 mangling/demangling, virtual function calls, print virtual table,
4749 call methods, ...etc.
4751 *** Changes in GDB-4.10:
4753 * User visible changes:
4755 Remote debugging using the GDB-specific (`target remote') protocol now
4756 supports the `load' command. This is only useful if you have some
4757 other way of getting the stub to the target system, and you can put it
4758 somewhere in memory where it won't get clobbered by the download.
4760 Filename completion now works.
4762 When run under emacs mode, the "info line" command now causes the
4763 arrow to point to the line specified. Also, "info line" prints
4764 addresses in symbolic form (as well as hex).
4766 All vxworks based targets now support a user settable option, called
4767 vxworks-timeout. This option represents the number of seconds gdb
4768 should wait for responses to rpc's. You might want to use this if
4769 your vxworks target is, perhaps, a slow software simulator or happens
4770 to be on the far side of a thin network line.
4774 This release contains support for using a DEC alpha as a GDB host for
4775 cross debugging. Native alpha debugging is not supported yet.
4778 *** Changes in GDB-4.9:
4782 This is the first GDB release which is accompanied by a matching testsuite.
4783 The testsuite requires installation of dejagnu, which should be available
4784 via ftp from most sites that carry GNU software.
4788 'Cfront' style demangling has had its name changed to 'ARM' style, to
4789 emphasize that it was written from the specifications in the C++ Annotated
4790 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4791 disclaimers, it still generated too much confusion with users attempting to
4792 use gdb with AT&T cfront.
4796 GDB now uses a standard remote interface to a simulator library.
4797 So far, the library contains simulators for the Zilog Z8001/2, the
4798 Hitachi H8/300, H8/500 and Super-H.
4800 * New targets supported
4802 H8/300 simulator h8300-hitachi-hms or h8300hms
4803 H8/500 simulator h8500-hitachi-hms or h8500hms
4804 SH simulator sh-hitachi-hms or sh
4805 Z8000 simulator z8k-zilog-none or z8ksim
4806 IDT MIPS board over serial line mips-idt-ecoff
4808 Cross-debugging to GO32 targets is supported. It requires a custom
4809 version of the i386-stub.c module which is integrated with the
4810 GO32 memory extender.
4812 * New remote protocols
4814 MIPS remote debugging protocol.
4816 * New source languages supported
4818 This version includes preliminary support for Chill, a Pascal like language
4819 used by telecommunications companies. Chill support is also being integrated
4820 into the GNU compiler, but we don't know when it will be publically available.
4823 *** Changes in GDB-4.8:
4825 * HP Precision Architecture supported
4827 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4828 version of this support was available as a set of patches from the
4829 University of Utah. GDB does not support debugging of programs
4830 compiled with the HP compiler, because HP will not document their file
4831 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4832 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4834 Many problems in the preliminary version have been fixed.
4836 * Faster and better demangling
4838 We have improved template demangling and fixed numerous bugs in the GNU style
4839 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4840 character types (wchar_t) are now supported. Demangling of each symbol is now
4841 only done once, and is cached when the symbol table for a file is read in.
4842 This results in a small increase in memory usage for C programs, a moderate
4843 increase in memory usage for C++ programs, and a fantastic speedup in
4846 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4847 from the specifications in the Annotated Reference Manual, which AT&T's
4848 compiler does not actually implement.
4850 * G++ multiple inheritance compiler problem
4852 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4853 inheritance lattices was reworked to properly discover ambiguities. We
4854 recently found an example which causes this new algorithm to fail in a
4855 very subtle way, producing bad debug information for those classes.
4856 The file 'gcc.patch' (in this directory) can be applied to gcc to
4857 circumvent the problem. A future GCC release will contain a complete
4860 The previous G++ debug info problem (mentioned below for the gdb-4.7
4861 release) is fixed in gcc version 2.3.2.
4863 * Improved configure script
4865 The `configure' script will now attempt to guess your system type if
4866 you don't supply a host system type. The old scheme of supplying a
4867 host system triplet is preferable over using this. All the magic is
4868 done in the new `config.guess' script. Examine it for details.
4870 We have also brought our configure script much more in line with the FSF's
4871 version. It now supports the --with-xxx options. In particular,
4872 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4873 The resulting GDB will not be able to read arbitrary object file formats --
4874 only the format ``expected'' to be used on the configured target system.
4875 We hope to make this the default in a future release.
4877 * Documentation improvements
4879 There's new internal documentation on how to modify GDB, and how to
4880 produce clean changes to the code. We implore people to read it
4881 before submitting changes.
4883 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4884 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4885 `info' files are also provided. To build `info' files from scratch,
4886 you will need the latest `makeinfo' release, which will be available in
4887 a future texinfo-X.Y release.
4889 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4890 We're not sure exactly which versions have this problem, but it has
4891 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4892 or better. If that isn't possible, there is a patch in
4893 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4894 around this problem.
4898 GDB now supports array constants that can be used in expressions typed in by
4899 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4900 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4903 The new directory `gdb/sparclite' contains a program that demonstrates
4904 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4906 * New native hosts supported
4908 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4909 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4911 * New targets supported
4913 AMD 29k family via UDI a29k-amd-udi or udi29k
4915 * New file formats supported
4917 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4918 HPUX core files, and SCO 3.2v2 core files.
4922 Attaching to processes now works again; thanks for the many bug reports.
4924 We have also stomped on a bunch of core dumps caused by
4925 printf_filtered("%s") problems.
4927 We eliminated a copyright problem on the rpc and ptrace header files
4928 for VxWorks, which was discovered at the last minute during the 4.7
4929 release. You should now be able to build a VxWorks GDB.
4931 You can now interrupt gdb while an attached process is running. This
4932 will cause the attached process to stop, and give control back to GDB.
4934 We fixed problems caused by using too many file descriptors
4935 for reading symbols from object files and libraries. This was
4936 especially a problem for programs that used many (~100) shared
4939 The `step' command now only enters a subroutine if there is line number
4940 information for the subroutine. Otherwise it acts like the `next'
4941 command. Previously, `step' would enter subroutines if there was
4942 any debugging information about the routine. This avoids problems
4943 when using `cc -g1' on MIPS machines.
4945 * Internal improvements
4947 GDB's internal interfaces have been improved to make it easier to support
4948 debugging of multiple languages in the future.
4950 GDB now uses a common structure for symbol information internally.
4951 Minimal symbols (derived from linkage symbols in object files), partial
4952 symbols (from a quick scan of debug information), and full symbols
4953 contain a common subset of information, making it easier to write
4954 shared code that handles any of them.
4956 * New command line options
4958 We now accept --silent as an alias for --quiet.
4962 The memory-mapped-malloc library is now licensed under the GNU Library
4963 General Public License.
4965 *** Changes in GDB-4.7:
4967 * Host/native/target split
4969 GDB has had some major internal surgery to untangle the support for
4970 hosts and remote targets. Now, when you configure GDB for a remote
4971 target, it will no longer load in all of the support for debugging
4972 local programs on the host. When fully completed and tested, this will
4973 ensure that arbitrary host/target combinations are possible.
4975 The primary conceptual shift is to separate the non-portable code in
4976 GDB into three categories. Host specific code is required any time GDB
4977 is compiled on that host, regardless of the target. Target specific
4978 code relates to the peculiarities of the target, but can be compiled on
4979 any host. Native specific code is everything else: it can only be
4980 built when the host and target are the same system. Child process
4981 handling and core file support are two common `native' examples.
4983 GDB's use of /proc for controlling Unix child processes is now cleaner.
4984 It has been split out into a single module under the `target_ops' vector,
4985 plus two native-dependent functions for each system that uses /proc.
4987 * New hosts supported
4989 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4990 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4991 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4993 * New targets supported
4995 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4996 68030 and CPU32 m68030-*-*, m68332-*-*
4998 * New native hosts supported
5000 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5001 (386bsd is not well tested yet)
5002 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5004 * New file formats supported
5006 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5007 supports reading of `a.out.adobe' object files, which are an a.out
5008 format extended with minimal information about multiple sections.
5012 `show copying' is the same as the old `info copying'.
5013 `show warranty' is the same as `info warrantee'.
5014 These were renamed for consistency. The old commands continue to work.
5016 `info handle' is a new alias for `info signals'.
5018 You can now define pre-command hooks, which attach arbitrary command
5019 scripts to any command. The commands in the hook will be executed
5020 prior to the user's command. You can also create a hook which will be
5021 executed whenever the program stops. See gdb.texinfo.
5025 We now deal with Cfront style name mangling, and can even extract type
5026 info from mangled symbols. GDB can automatically figure out which
5027 symbol mangling style your C++ compiler uses.
5029 Calling of methods and virtual functions has been improved as well.
5033 The crash that occured when debugging Sun Ansi-C compiled binaries is
5034 fixed. This was due to mishandling of the extra N_SO stabs output
5037 We also finally got Ultrix 4.2 running in house, and fixed core file
5038 support, with help from a dozen people on the net.
5040 John M. Farrell discovered that the reason that single-stepping was so
5041 slow on all of the Mips based platforms (primarily SGI and DEC) was
5042 that we were trying to demangle and lookup a symbol used for internal
5043 purposes on every instruction that was being stepped through. Changing
5044 the name of that symbol so that it couldn't be mistaken for a C++
5045 mangled symbol sped things up a great deal.
5047 Rich Pixley sped up symbol lookups in general by getting much smarter
5048 about when C++ symbol mangling is necessary. This should make symbol
5049 completion (TAB on the command line) much faster. It's not as fast as
5050 we'd like, but it's significantly faster than gdb-4.6.
5054 A new user controllable variable 'call_scratch_address' can
5055 specify the location of a scratch area to be used when GDB
5056 calls a function in the target. This is necessary because the
5057 usual method of putting the scratch area on the stack does not work
5058 in systems that have separate instruction and data spaces.
5060 We integrated changes to support the 29k UDI (Universal Debugger
5061 Interface), but discovered at the last minute that we didn't have all
5062 of the appropriate copyright paperwork. We are working with AMD to
5063 resolve this, and hope to have it available soon.
5067 We have sped up the remote serial line protocol, especially for targets
5068 with lots of registers. It now supports a new `expedited status' ('T')
5069 message which can be used in place of the existing 'S' status message.
5070 This allows the remote stub to send only the registers that GDB
5071 needs to make a quick decision about single-stepping or conditional
5072 breakpoints, eliminating the need to fetch the entire register set for
5073 each instruction being stepped through.
5075 The GDB remote serial protocol now implements a write-through cache for
5076 registers, only re-reading the registers if the target has run.
5078 There is also a new remote serial stub for SPARC processors. You can
5079 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5080 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5081 processor with a serial port.
5085 Configure.in files have become much easier to read and modify. A new
5086 `table driven' format makes it more obvious what configurations are
5087 supported, and what files each one uses.
5091 There is a new opcodes library which will eventually contain all of the
5092 disassembly routines and opcode tables. At present, it only contains
5093 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5094 disassembler (binutils/objdump) to share these routines.
5096 The libiberty library is now copylefted under the GNU Library General
5097 Public License. This allows more liberal use, and was done so libg++
5098 can use it. This makes no difference to GDB, since the Library License
5099 grants all the rights from the General Public License.
5103 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5104 reference to the stabs symbol info used by the debugger. It is (as far
5105 as we know) the only published document on this fascinating topic. We
5106 encourage you to read it, compare it to the stabs information on your
5107 system, and send improvements on the document in general (to
5108 bug-gdb@prep.ai.mit.edu).
5110 And, of course, many bugs have been fixed.
5113 *** Changes in GDB-4.6:
5115 * Better support for C++ function names
5117 GDB now accepts as input the "demangled form" of C++ overloaded function
5118 names and member function names, and can do command completion on such names
5119 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5120 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5121 Make use of command completion, it is your friend.
5123 GDB also now accepts a variety of C++ mangled symbol formats. They are
5124 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5125 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5126 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5127 for the list of formats.
5129 * G++ symbol mangling problem
5131 Recent versions of gcc have a bug in how they emit debugging information for
5132 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5133 directory) can be applied to gcc to fix the problem. Alternatively, if you
5134 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5135 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5136 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5139 * New 'maintenance' command
5141 All of the commands related to hacking GDB internals have been moved out of
5142 the main command set, and now live behind the 'maintenance' command. This
5143 can also be abbreviated as 'mt'. The following changes were made:
5145 dump-me -> maintenance dump-me
5146 info all-breakpoints -> maintenance info breakpoints
5147 printmsyms -> maintenance print msyms
5148 printobjfiles -> maintenance print objfiles
5149 printpsyms -> maintenance print psymbols
5150 printsyms -> maintenance print symbols
5152 The following commands are new:
5154 maintenance demangle Call internal GDB demangler routine to
5155 demangle a C++ link name and prints the result.
5156 maintenance print type Print a type chain for a given symbol
5158 * Change to .gdbinit file processing
5160 We now read the $HOME/.gdbinit file before processing the argv arguments
5161 (e.g. reading symbol files or core files). This allows global parameters to
5162 be set, which will apply during the symbol reading. The ./.gdbinit is still
5163 read after argv processing.
5165 * New hosts supported
5167 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5169 GNU/Linux support i386-unknown-linux or linux
5171 We are also including code to support the HP/PA running BSD and HPUX. This
5172 is almost guaranteed not to work, as we didn't have time to test or build it
5173 for this release. We are including it so that the more adventurous (or
5174 masochistic) of you can play with it. We also had major problems with the
5175 fact that the compiler that we got from HP doesn't support the -g option.
5178 * New targets supported
5180 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5182 * More smarts about finding #include files
5184 GDB now remembers the compilation directory for all include files, and for
5185 all files from which C is generated (like yacc and lex sources). This
5186 greatly improves GDB's ability to find yacc/lex sources, and include files,
5187 especially if you are debugging your program from a directory different from
5188 the one that contains your sources.
5190 We also fixed a bug which caused difficulty with listing and setting
5191 breakpoints in include files which contain C code. (In the past, you had to
5192 try twice in order to list an include file that you hadn't looked at before.)
5194 * Interesting infernals change
5196 GDB now deals with arbitrary numbers of sections, where the symbols for each
5197 section must be relocated relative to that section's landing place in the
5198 target's address space. This work was needed to support ELF with embedded
5199 stabs used by Solaris-2.0.
5201 * Bug fixes (of course!)
5203 There have been loads of fixes for the following things:
5204 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5205 i960, stabs, DOS(GO32), procfs, etc...
5207 See the ChangeLog for details.
5209 *** Changes in GDB-4.5:
5211 * New machines supported (host and target)
5213 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5215 SGI Irix-4.x mips-sgi-irix4 or iris4
5217 * New malloc package
5219 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5220 Mmalloc is capable of handling mutiple heaps of memory. It is also
5221 capable of saving a heap to a file, and then mapping it back in later.
5222 This can be used to greatly speedup the startup of GDB by using a
5223 pre-parsed symbol table which lives in a mmalloc managed heap. For
5224 more details, please read mmalloc/mmalloc.texi.
5228 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5229 'help info proc' for details.
5231 * MIPS ecoff symbol table format
5233 The code that reads MIPS symbol table format is now supported on all hosts.
5234 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5237 * File name changes for MS-DOS
5239 Many files in the config directories have been renamed to make it easier to
5240 support GDB on MS-DOSe systems (which have very restrictive file name
5241 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5242 environment) is close to working but has some remaining problems. Note
5243 that debugging of DOS programs is not supported, due to limitations
5244 in the ``operating system'', but it can be used to host cross-debugging.
5246 * Cross byte order fixes
5248 Many fixes have been made to support cross debugging of Sparc and MIPS
5249 targets from hosts whose byte order differs.
5251 * New -mapped and -readnow options
5253 If memory-mapped files are available on your system through the 'mmap'
5254 system call, you can use the -mapped option on the `file' or
5255 `symbol-file' commands to cause GDB to write the symbols from your
5256 program into a reusable file. If the program you are debugging is
5257 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5258 Future GDB debugging sessions will notice the presence of this file,
5259 and will quickly map in symbol information from it, rather than reading
5260 the symbol table from the executable program. Using the '-mapped'
5261 option in a GDB `file' or `symbol-file' command has the same effect as
5262 starting GDB with the '-mapped' command-line option.
5264 You can cause GDB to read the entire symbol table immediately by using
5265 the '-readnow' option with any of the commands that load symbol table
5266 information (or on the GDB command line). This makes the command
5267 slower, but makes future operations faster.
5269 The -mapped and -readnow options are typically combined in order to
5270 build a `fred.syms' file that contains complete symbol information.
5271 A simple GDB invocation to do nothing but build a `.syms' file for future
5274 gdb -batch -nx -mapped -readnow programname
5276 The `.syms' file is specific to the host machine on which GDB is run.
5277 It holds an exact image of GDB's internal symbol table. It cannot be
5278 shared across multiple host platforms.
5280 * longjmp() handling
5282 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5283 siglongjmp() without losing control. This feature has not yet been ported to
5284 all systems. It currently works on many 386 platforms, all MIPS-based
5285 platforms (SGI, DECstation, etc), and Sun3/4.
5289 Preliminary work has been put in to support the new Solaris OS from Sun. At
5290 this time, it can control and debug processes, but it is not capable of
5295 As always, many many bug fixes. The major areas were with g++, and mipsread.
5296 People using the MIPS-based platforms should experience fewer mysterious
5297 crashes and trashed symbol tables.
5299 *** Changes in GDB-4.4:
5301 * New machines supported (host and target)
5303 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5305 BSD Reno on Vax vax-dec-bsd
5306 Ultrix on Vax vax-dec-ultrix
5308 * New machines supported (target)
5310 AMD 29000 embedded, using EBMON a29k-none-none
5314 GDB continues to improve its handling of C++. `References' work better.
5315 The demangler has also been improved, and now deals with symbols mangled as
5316 per the Annotated C++ Reference Guide.
5318 GDB also now handles `stabs' symbol information embedded in MIPS
5319 `ecoff' symbol tables. Since the ecoff format was not easily
5320 extensible to handle new languages such as C++, this appeared to be a
5321 good way to put C++ debugging info into MIPS binaries. This option
5322 will be supported in the GNU C compiler, version 2, when it is
5325 * New features for SVR4
5327 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5328 shared libraries. Debugging dynamically linked programs should present
5329 only minor differences from debugging statically linked programs.
5331 The `info proc' command will print out information about any process
5332 on an SVR4 system (including the one you are debugging). At the moment,
5333 it prints the address mappings of the process.
5335 If you bring up GDB on another SVR4 system, please send mail to
5336 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5338 * Better dynamic linking support in SunOS
5340 Reading symbols from shared libraries which contain debugging symbols
5341 now works properly. However, there remain issues such as automatic
5342 skipping of `transfer vector' code during function calls, which
5343 make it harder to debug code in a shared library, than to debug the
5344 same code linked statically.
5348 GDB is now using the latest `getopt' routines from the FSF. This
5349 version accepts the -- prefix for options with long names. GDB will
5350 continue to accept the old forms (-option and +option) as well.
5351 Various single letter abbreviations for options have been explicity
5352 added to the option table so that they won't get overshadowed in the
5353 future by other options that begin with the same letter.
5357 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5358 Many assorted bugs have been handled. Many more remain to be handled.
5359 See the various ChangeLog files (primarily in gdb and bfd) for details.
5362 *** Changes in GDB-4.3:
5364 * New machines supported (host and target)
5366 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5367 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5368 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5370 * Almost SCO Unix support
5372 We had hoped to support:
5373 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5374 (except for core file support), but we discovered very late in the release
5375 that it has problems with process groups that render gdb unusable. Sorry
5376 about that. I encourage people to fix it and post the fixes.
5378 * Preliminary ELF and DWARF support
5380 GDB can read ELF object files on System V Release 4, and can handle
5381 debugging records for C, in DWARF format, in ELF files. This support
5382 is preliminary. If you bring up GDB on another SVR4 system, please
5383 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5388 GDB now uses the latest `readline' library. One user-visible change
5389 is that two tabs will list possible command completions, which previously
5390 required typing M-? (meta-question mark, or ESC ?).
5394 The `stepi' bug that many of you noticed has been squashed.
5395 Many bugs in C++ have been handled. Many more remain to be handled.
5396 See the various ChangeLog files (primarily in gdb and bfd) for details.
5398 * State of the MIPS world (in case you wondered):
5400 GDB can understand the symbol tables emitted by the compilers
5401 supplied by most vendors of MIPS-based machines, including DEC. These
5402 symbol tables are in a format that essentially nobody else uses.
5404 Some versions of gcc come with an assembler post-processor called
5405 mips-tfile. This program is required if you want to do source-level
5406 debugging of gcc-compiled programs. I believe FSF does not ship
5407 mips-tfile with gcc version 1, but it will eventually come with gcc
5410 Debugging of g++ output remains a problem. g++ version 1.xx does not
5411 really support it at all. (If you're lucky, you should be able to get
5412 line numbers and stack traces to work, but no parameters or local
5413 variables.) With some work it should be possible to improve the
5416 When gcc version 2 is released, you will have somewhat better luck.
5417 However, even then you will get confusing results for inheritance and
5420 We will eventually provide full debugging of g++ output on
5421 DECstations. This will probably involve some kind of stabs-in-ecoff
5422 encapulation, but the details have not been worked out yet.
5425 *** Changes in GDB-4.2:
5427 * Improved configuration
5429 Only one copy of `configure' exists now, and it is not self-modifying.
5430 Porting BFD is simpler.
5434 The `step' and `next' commands now only stop at the first instruction
5435 of a source line. This prevents the multiple stops that used to occur
5436 in switch statements, for-loops, etc. `Step' continues to stop if a
5437 function that has debugging information is called within the line.
5441 Lots of small bugs fixed. More remain.
5443 * New host supported (not target)
5445 Intel 386 PC clone running Mach i386-none-mach
5448 *** Changes in GDB-4.1:
5450 * Multiple source language support
5452 GDB now has internal scaffolding to handle several source languages.
5453 It determines the type of each source file from its filename extension,
5454 and will switch expression parsing and number formatting to match the
5455 language of the function in the currently selected stack frame.
5456 You can also specifically set the language to be used, with
5457 `set language c' or `set language modula-2'.
5461 GDB now has preliminary support for the GNU Modula-2 compiler,
5462 currently under development at the State University of New York at
5463 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5464 continue through the fall of 1991 and into 1992.
5466 Other Modula-2 compilers are currently not supported, and attempting to
5467 debug programs compiled with them will likely result in an error as the
5468 symbol table is read. Feel free to work on it, though!
5470 There are hooks in GDB for strict type checking and range checking,
5471 in the `Modula-2 philosophy', but they do not currently work.
5475 GDB can now write to executable and core files (e.g. patch
5476 a variable's value). You must turn this switch on, specify
5477 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5478 by assigning a new value to a variable. Modifications take
5481 * Automatic SunOS shared library reading
5483 When you run your program, GDB automatically determines where its
5484 shared libraries (if any) have been loaded, and reads their symbols.
5485 The `share' command is no longer needed. This also works when
5486 examining core files.
5490 You can specify the number of lines that the `list' command shows.
5493 * New machines supported (host and target)
5495 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5496 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5497 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5499 * New hosts supported (not targets)
5501 IBM RT/PC: romp-ibm-aix or rtpc
5503 * New targets supported (not hosts)
5505 AMD 29000 embedded with COFF a29k-none-coff
5506 AMD 29000 embedded with a.out a29k-none-aout
5507 Ultracomputer remote kernel debug a29k-nyu-kern
5509 * New remote interfaces
5515 *** Changes in GDB-4.0:
5519 Wide output is wrapped at good places to make the output more readable.
5521 Gdb now supports cross-debugging from a host machine of one type to a
5522 target machine of another type. Communication with the target system
5523 is over serial lines. The ``target'' command handles connecting to the
5524 remote system; the ``load'' command will download a program into the
5525 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5526 also supports debugging of realtime processes running under VxWorks,
5527 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5528 stub on the target system.
5530 New CPUs supported include the AMD 29000 and Intel 960.
5532 GDB now reads object files and symbol tables via a ``binary file''
5533 library, which allows a single copy of GDB to debug programs of multiple
5534 object file types such as a.out and coff.
5536 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5537 refcard.dvi and refcard.ps are available to format it).
5540 * Control-Variable user interface simplified
5542 All variables that control the operation of the debugger can be set
5543 by the ``set'' command, and displayed by the ``show'' command.
5545 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5546 ``Show prompt'' produces the response:
5547 Gdb's prompt is new-gdb=>.
5549 What follows are the NEW set commands. The command ``help set'' will
5550 print a complete list of old and new set commands. ``help set FOO''
5551 will give a longer description of the variable FOO. ``show'' will show
5552 all of the variable descriptions and their current settings.
5554 confirm on/off: Enables warning questions for operations that are
5555 hard to recover from, e.g. rerunning the program while
5556 it is already running. Default is ON.
5558 editing on/off: Enables EMACS style command line editing
5559 of input. Previous lines can be recalled with
5560 control-P, the current line can be edited with control-B,
5561 you can search for commands with control-R, etc.
5564 history filename NAME: NAME is where the gdb command history
5565 will be stored. The default is .gdb_history,
5566 or the value of the environment variable
5569 history size N: The size, in commands, of the command history. The
5570 default is 256, or the value of the environment variable
5573 history save on/off: If this value is set to ON, the history file will
5574 be saved after exiting gdb. If set to OFF, the
5575 file will not be saved. The default is OFF.
5577 history expansion on/off: If this value is set to ON, then csh-like
5578 history expansion will be performed on
5579 command line input. The default is OFF.
5581 radix N: Sets the default radix for input and output. It can be set
5582 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5583 in the current radix, so "set radix 10" is always a no-op.
5585 height N: This integer value is the number of lines on a page. Default
5586 is 24, the current `stty rows'' setting, or the ``li#''
5587 setting from the termcap entry matching the environment
5590 width N: This integer value is the number of characters on a line.
5591 Default is 80, the current `stty cols'' setting, or the ``co#''
5592 setting from the termcap entry matching the environment
5595 Note: ``set screensize'' is obsolete. Use ``set height'' and
5596 ``set width'' instead.
5598 print address on/off: Print memory addresses in various command displays,
5599 such as stack traces and structure values. Gdb looks
5600 more ``symbolic'' if you turn this off; it looks more
5601 ``machine level'' with it on. Default is ON.
5603 print array on/off: Prettyprint arrays. New convenient format! Default
5606 print demangle on/off: Print C++ symbols in "source" form if on,
5609 print asm-demangle on/off: Same, for assembler level printouts
5612 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5615 * Support for Epoch Environment.
5617 The epoch environment is a version of Emacs v18 with windowing. One
5618 new command, ``inspect'', is identical to ``print'', except that if you
5619 are running in the epoch environment, the value is printed in its own
5623 * Support for Shared Libraries
5625 GDB can now debug programs and core files that use SunOS shared libraries.
5626 Symbols from a shared library cannot be referenced
5627 before the shared library has been linked with the program (this
5628 happens after you type ``run'' and before the function main() is entered).
5629 At any time after this linking (including when examining core files
5630 from dynamically linked programs), gdb reads the symbols from each
5631 shared library when you type the ``sharedlibrary'' command.
5632 It can be abbreviated ``share''.
5634 sharedlibrary REGEXP: Load shared object library symbols for files
5635 matching a unix regular expression. No argument
5636 indicates to load symbols for all shared libraries.
5638 info sharedlibrary: Status of loaded shared libraries.
5643 A watchpoint stops execution of a program whenever the value of an
5644 expression changes. Checking for this slows down execution
5645 tremendously whenever you are in the scope of the expression, but is
5646 quite useful for catching tough ``bit-spreader'' or pointer misuse
5647 problems. Some machines such as the 386 have hardware for doing this
5648 more quickly, and future versions of gdb will use this hardware.
5650 watch EXP: Set a watchpoint (breakpoint) for an expression.
5652 info watchpoints: Information about your watchpoints.
5654 delete N: Deletes watchpoint number N (same as breakpoints).
5655 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5656 enable N: Re-enables watchpoint number N (same as breakpoints).
5659 * C++ multiple inheritance
5661 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5664 * C++ exception handling
5666 Gdb now supports limited C++ exception handling. Besides the existing
5667 ability to breakpoint on an exception handler, gdb can breakpoint on
5668 the raising of an exception (before the stack is peeled back to the
5671 catch FOO: If there is a FOO exception handler in the dynamic scope,
5672 set a breakpoint to catch exceptions which may be raised there.
5673 Multiple exceptions (``catch foo bar baz'') may be caught.
5675 info catch: Lists all exceptions which may be caught in the
5676 current stack frame.
5679 * Minor command changes
5681 The command ``call func (arg, arg, ...)'' now acts like the print
5682 command, except it does not print or save a value if the function's result
5683 is void. This is similar to dbx usage.
5685 The ``up'' and ``down'' commands now always print the frame they end up
5686 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5687 frames without printing.
5689 * New directory command
5691 'dir' now adds directories to the FRONT of the source search path.
5692 The path starts off empty. Source files that contain debug information
5693 about the directory in which they were compiled can be found even
5694 with an empty path; Sun CC and GCC include this information. If GDB can't
5695 find your source file in the current directory, type "dir .".
5697 * Configuring GDB for compilation
5699 For normal use, type ``./configure host''. See README or gdb.texinfo
5702 GDB now handles cross debugging. If you are remotely debugging between
5703 two different machines, type ``./configure host -target=targ''.
5704 Host is the machine where GDB will run; targ is the machine
5705 where the program that you are debugging will run.
5707 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
5709 * Support for Intel(R) AVX-512 registers on GNU/Linux.
5711 Support displaying and modifying Intel(R) AVX-512 registers $zmm0 - $zmm31 and
5712 $k0 - $k7 on GNU/Linux.