1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.8
7 You can now access frame registers from Python scripts.
9 * New Python-based convenience functions:
11 ** $_caller_is(name [, number_of_frames])
12 ** $_caller_matches(regexp [, number_of_frames])
13 ** $_any_caller_is(name [, number_of_frames])
14 ** $_any_caller_matches(regexp [, number_of_frames])
18 queue-signal signal-name-or-number
19 Queue a signal to be delivered to the thread when it is resumed.
21 * On resume, GDB now always passes the signal the program had stopped
22 for to the thread the signal was sent to, even if the user changed
23 threads before resuming. Previously GDB would often (but not
24 always) deliver the signal to the thread that happens to be current
27 * Conversely, the "signal" command now consistently delivers the
28 requested signal to the current thread. GDB now asks for
29 confirmation if the program had stopped for a signal and the user
30 switched threads meanwhile.
32 *** Changes in GDB 7.8
34 * New command line options
37 This is an alias for the --data-directory option.
39 * GDB supports printing and modifying of variable length automatic arrays
40 as specified in ISO C99.
42 * The ARM simulator now supports instruction level tracing
43 with or without disassembly.
47 GDB now has support for scripting using Guile. Whether this is
48 available is determined at configure time.
49 Guile version 2.0 or greater is required.
50 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
52 * New commands (for set/show, see "New options" below)
56 Invoke CODE by passing it to the Guile interpreter.
60 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
62 info auto-load guile-scripts [regexp]
63 Print the list of automatically loaded Guile scripts.
65 * The source command is now capable of sourcing Guile scripts.
66 This feature is dependent on the debugger being built with Guile support.
70 set print symbol-loading (off|brief|full)
71 show print symbol-loading
72 Control whether to print informational messages when loading symbol
73 information for a file. The default is "full", but when debugging
74 programs with large numbers of shared libraries the amount of output
77 set guile print-stack (none|message|full)
78 show guile print-stack
79 Show a stack trace when an error is encountered in a Guile script.
81 set auto-load guile-scripts (on|off)
82 show auto-load guile-scripts
83 Control auto-loading of Guile script files.
85 maint ada set ignore-descriptive-types (on|off)
86 maint ada show ignore-descriptive-types
87 Control whether the debugger should ignore descriptive types in Ada
88 programs. The default is not to ignore the descriptive types. See
89 the user manual for more details on descriptive types and the intended
92 set auto-connect-native-target
94 Control whether GDB is allowed to automatically connect to the
95 native target for the run, attach, etc. commands when not connected
96 to any target yet. See also "target native" below.
98 set record btrace replay-memory-access (read-only|read-write)
99 show record btrace replay-memory-access
100 Control what memory accesses are allowed during replay.
102 maint set target-async (on|off)
103 maint show target-async
104 This controls whether GDB targets operate in syncronous or
105 asyncronous mode. Normally the default is asyncronous, if it is
106 available; but this can be changed to more easily debug problems
107 occurring only in syncronous mode.
109 set mi-async (on|off)
111 Control whether MI asynchronous mode is preferred. This supersedes
112 "set target-async" of previous GDB versions.
114 * "set target-async" is deprecated as a CLI option and is now an alias
115 for "set mi-async" (only puts MI into async mode).
117 * Background execution commands (e.g., "c&", "s&", etc.) are now
118 possible ``out of the box'' if the target supports them. Previously
119 the user would need to explicitly enable the possibility with the
120 "set target-async on" command.
122 * New features in the GDB remote stub, GDBserver
124 ** New option --debug-format=option1[,option2,...] allows one to add
125 additional text to each output. At present only timestamps
126 are supported: --debug-format=timestamps.
127 Timestamps can also be turned on with the
128 "monitor set debug-format timestamps" command from GDB.
130 * The 'record instruction-history' command now starts counting instructions
131 at one. This also affects the instruction ranges reported by the
132 'record function-call-history' command when given the /i modifier.
134 * The command 'record function-call-history' supports a new modifier '/c' to
135 indent the function names based on their call stack depth.
136 The fields for the '/i' and '/l' modifier have been reordered.
137 The source line range is now prefixed with 'at'.
138 The instruction range is now prefixed with 'inst'.
139 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
140 "record instruction-history" and "list" commands.
142 * The ranges given as arguments to the 'record function-call-history' and
143 'record instruction-history' commands are now inclusive.
145 * The btrace record target now supports the 'record goto' command.
146 For locations inside the execution trace, the back trace is computed
147 based on the information stored in the execution trace.
149 * The btrace record target supports limited reverse execution and replay.
150 The target does not record data and therefore does not allow reading
153 * The "catch syscall" command now works on s390*-linux* targets.
155 * The "compare-sections" command is no longer specific to target
156 remote. It now works with all targets.
158 * All native targets are now consistently called "native".
159 Consequently, the "target child", "target GNU", "target djgpp",
160 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
161 commands have been replaced with "target native". The QNX/NTO port
162 leaves the "procfs" target in place and adds a "native" target for
163 consistency with other ports. The impact on users should be minimal
164 as these commands previously either throwed an error, or were
165 no-ops. The target's name is visible in the output of the following
166 commands: "help target", "info target", "info files", "maint print
169 * The "target native" command now connects to the native target. This
170 can be used to launch native programs even when "set
171 auto-connect-native-target" is set to off.
173 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
175 * Support for Intel(R) AVX-512 registers on GNU/Linux.
176 Support displaying and modifying Intel(R) AVX-512 registers
177 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
181 qXfer:btrace:read's annex
182 The qXfer:btrace:read packet supports a new annex 'delta' to read
183 branch trace incrementally.
187 ** Valid Python operations on gdb.Value objects representing
188 structs/classes invoke the corresponding overloaded operators if
190 ** New `Xmethods' feature in the Python API. Xmethods are
191 additional methods or replacements for existing methods of a C++
192 class. This feature is useful for those cases where a method
193 defined in C++ source code could be inlined or optimized out by
194 the compiler, making it unavailable to GDB.
197 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
199 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
200 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
201 its alias "share", instead.
203 * The commands "set remotebaud" and "show remotebaud" are no longer
204 supported. Use "set serial baud" and "show serial baud" (respectively)
209 ** A new option "-gdb-set mi-async" replaces "-gdb-set
210 target-async". The latter is left as a deprecated alias of the
211 former for backward compatibility. If the target supports it,
212 CLI background execution commands are now always possible by
213 default, independently of whether the frontend stated a
214 preference for asynchronous execution with "-gdb-set mi-async".
215 Previously "-gdb-set target-async off" affected both MI execution
216 commands and CLI execution commands.
218 *** Changes in GDB 7.7
220 * Improved support for process record-replay and reverse debugging on
221 arm*-linux* targets. Support for thumb32 and syscall instruction
222 recording has been added.
224 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
226 * GDB now supports Fission DWP file format version 2.
227 http://gcc.gnu.org/wiki/DebugFission
229 * New convenience function "$_isvoid", to check whether an expression
230 is void. A void expression is an expression where the type of the
231 result is "void". For example, some convenience variables may be
232 "void" when evaluated (e.g., "$_exitcode" before the execution of
233 the program being debugged; or an undefined convenience variable).
234 Another example, when calling a function whose return type is
237 * The "maintenance print objfiles" command now takes an optional regexp.
239 * The "catch syscall" command now works on arm*-linux* targets.
241 * GDB now consistently shows "<not saved>" when printing values of
242 registers the debug info indicates have not been saved in the frame
243 and there's nowhere to retrieve them from
244 (callee-saved/call-clobbered registers):
249 (gdb) info registers rax
252 Before, the former would print "<optimized out>", and the latter
253 "*value not available*".
255 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
260 ** Frame filters and frame decorators have been added.
261 ** Temporary breakpoints are now supported.
262 ** Line tables representation has been added.
263 ** New attribute 'parent_type' for gdb.Field objects.
264 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
265 ** New attribute 'name' for gdb.Type objects.
269 Nios II ELF nios2*-*-elf
270 Nios II GNU/Linux nios2*-*-linux
271 Texas Instruments MSP430 msp430*-*-elf
273 * Removed native configurations
275 Support for these a.out NetBSD and OpenBSD obsolete configurations has
276 been removed. ELF variants of these configurations are kept supported.
278 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
279 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
280 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
281 i[34567]86-*-openbsd3.[0-3]
282 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
283 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
284 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
288 Like "catch throw", but catches a re-thrown exception.
290 Renamed from old "maint check-symtabs".
292 Perform consistency checks on symtabs.
294 Expand symtabs matching an optional regexp.
297 Display the details of GDB configure-time options.
299 maint set|show per-command
300 maint set|show per-command space
301 maint set|show per-command time
302 maint set|show per-command symtab
303 Enable display of per-command gdb resource usage.
305 remove-symbol-file FILENAME
306 remove-symbol-file -a ADDRESS
307 Remove a symbol file added via add-symbol-file. The file to remove
308 can be identified by its filename or by an address that lies within
309 the boundaries of this symbol file in memory.
312 info exceptions REGEXP
313 Display the list of Ada exceptions defined in the program being
314 debugged. If provided, only the exceptions whose names match REGEXP
319 set debug symfile off|on
321 Control display of debugging info regarding reading symbol files and
322 symbol tables within those files
324 set print raw frame-arguments
325 show print raw frame-arguments
326 Set/show whether to print frame arguments in raw mode,
327 disregarding any defined pretty-printers.
329 set remote trace-status-packet
330 show remote trace-status-packet
331 Set/show the use of remote protocol qTStatus packet.
335 Control display of debugging messages related to Nios II targets.
339 Control whether target-assisted range stepping is enabled.
341 set startup-with-shell
342 show startup-with-shell
343 Specifies whether Unix child processes are started via a shell or
348 Use the target memory cache for accesses to the code segment. This
349 improves performance of remote debugging (particularly disassembly).
351 * You can now use a literal value 'unlimited' for options that
352 interpret 0 or -1 as meaning "unlimited". E.g., "set
353 trace-buffer-size unlimited" is now an alias for "set
354 trace-buffer-size -1" and "set height unlimited" is now an alias for
357 * The "set debug symtab-create" debugging option of GDB has been changed to
358 accept a verbosity level. 0 means "off", 1 provides basic debugging
359 output, and values of 2 or greater provides more verbose output.
361 * New command-line options
363 Display the details of GDB configure-time options.
365 * The command 'tsave' can now support new option '-ctf' to save trace
366 buffer in Common Trace Format.
368 * Newly installed $prefix/bin/gcore acts as a shell interface for the
371 * GDB now implements the the C++ 'typeid' operator.
373 * The new convenience variable $_exception holds the exception being
374 thrown or caught at an exception-related catchpoint.
376 * The exception-related catchpoints, like "catch throw", now accept a
377 regular expression which can be used to filter exceptions by type.
379 * The new convenience variable $_exitsignal is automatically set to
380 the terminating signal number when the program being debugged dies
381 due to an uncaught signal.
385 ** All MI commands now accept an optional "--language" option.
386 Support for this feature can be verified by using the "-list-features"
387 command, which should contain "language-option".
389 ** The new command -info-gdb-mi-command allows the user to determine
390 whether a GDB/MI command is supported or not.
392 ** The "^error" result record returned when trying to execute an undefined
393 GDB/MI command now provides a variable named "code" whose content is the
394 "undefined-command" error code. Support for this feature can be verified
395 by using the "-list-features" command, which should contain
396 "undefined-command-error-code".
398 ** The -trace-save MI command can optionally save trace buffer in Common
401 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
403 ** The command -data-list-register-values now accepts an optional
404 "--skip-unavailable" option. When used, only the available registers
407 ** The new command -trace-frame-collected dumps collected variables,
408 computed expressions, tvars, memory and registers in a traceframe.
410 ** The commands -stack-list-locals, -stack-list-arguments and
411 -stack-list-variables now accept an option "--skip-unavailable".
412 When used, only the available locals or arguments are displayed.
414 ** The -exec-run command now accepts an optional "--start" option.
415 When used, the command follows the same semantics as the "start"
416 command, stopping the program's execution at the start of its
417 main subprogram. Support for this feature can be verified using
418 the "-list-features" command, which should contain
419 "exec-run-start-option".
421 ** The new commands -catch-assert and -catch-exceptions insert
422 catchpoints stopping the program when Ada exceptions are raised.
424 ** The new command -info-ada-exceptions provides the equivalent of
425 the new "info exceptions" command.
427 * New system-wide configuration scripts
428 A GDB installation now provides scripts suitable for use as system-wide
429 configuration scripts for the following systems:
433 * GDB now supports target-assigned range stepping with remote targets.
434 This improves the performance of stepping source lines by reducing
435 the number of control packets from/to GDB. See "New remote packets"
438 * GDB now understands the element 'tvar' in the XML traceframe info.
439 It has the id of the collected trace state variables.
441 * On S/390 targets that provide the transactional-execution feature,
442 the program interruption transaction diagnostic block (TDB) is now
443 represented as a number of additional "registers" in GDB.
449 The vCont packet supports a new 'r' action, that tells the remote
450 stub to step through an address range itself, without GDB
451 involvemement at each single-step.
453 qXfer:libraries-svr4:read's annex
454 The previously unused annex of the qXfer:libraries-svr4:read packet
455 is now used to support passing an argument list. The remote stub
456 reports support for this argument list to GDB's qSupported query.
457 The defined arguments are "start" and "prev", used to reduce work
458 necessary for library list updating, resulting in significant
461 * New features in the GDB remote stub, GDBserver
463 ** GDBserver now supports target-assisted range stepping. Currently
464 enabled on x86/x86_64 GNU/Linux targets.
466 ** GDBserver now adds element 'tvar' in the XML in the reply to
467 'qXfer:traceframe-info:read'. It has the id of the collected
468 trace state variables.
470 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
473 * New 'z' formatter for printing and examining memory, this displays the
474 value as hexadecimal zero padded on the left to the size of the type.
476 * GDB can now use Windows x64 unwinding data.
478 * The "set remotebaud" command has been replaced by "set serial baud".
479 Similarly, "show remotebaud" has been replaced by "show serial baud".
480 The "set remotebaud" and "show remotebaud" commands are still available
481 to provide backward compatibility with older versions of GDB.
483 *** Changes in GDB 7.6
485 * Target record has been renamed to record-full.
486 Record/replay is now enabled with the "record full" command.
487 This also affects settings that are associated with full record/replay
488 that have been moved from "set/show record" to "set/show record full":
490 set|show record full insn-number-max
491 set|show record full stop-at-limit
492 set|show record full memory-query
494 * A new record target "record-btrace" has been added. The new target
495 uses hardware support to record the control-flow of a process. It
496 does not support replaying the execution, but it implements the
497 below new commands for investigating the recorded execution log.
498 This new recording method can be enabled using:
502 The "record-btrace" target is only available on Intel Atom processors
503 and requires a Linux kernel 2.6.32 or later.
505 * Two new commands have been added for record/replay to give information
506 about the recorded execution without having to replay the execution.
507 The commands are only supported by "record btrace".
509 record instruction-history prints the execution history at
510 instruction granularity
512 record function-call-history prints the execution history at
515 * New native configurations
517 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
518 FreeBSD/powerpc powerpc*-*-freebsd
519 x86_64/Cygwin x86_64-*-cygwin*
520 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
524 ARM AArch64 aarch64*-*-elf
525 ARM AArch64 GNU/Linux aarch64*-*-linux
526 Lynx 178 PowerPC powerpc-*-lynx*178
527 x86_64/Cygwin x86_64-*-cygwin*
528 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
530 * If the configured location of system.gdbinit file (as given by the
531 --with-system-gdbinit option at configure time) is in the
532 data-directory (as specified by --with-gdb-datadir at configure
533 time) or in one of its subdirectories, then GDB will look for the
534 system-wide init file in the directory specified by the
535 --data-directory command-line option.
537 * New command line options:
539 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
540 other initialization files, unlike -nx which disables all of them.
542 * Removed command line options
544 -epoch This was used by the gdb mode in Epoch, an ancient fork of
547 * The 'ptype' and 'whatis' commands now accept an argument to control
550 * 'info proc' now works on some core files.
554 ** Vectors can be created with gdb.Type.vector.
556 ** Python's atexit.register now works in GDB.
558 ** Types can be pretty-printed via a Python API.
560 ** Python 3 is now supported (in addition to Python 2.4 or later)
562 ** New class gdb.Architecture exposes GDB's internal representation
563 of architecture in the Python API.
565 ** New method Frame.architecture returns the gdb.Architecture object
566 corresponding to the frame's architecture.
568 * New Python-based convenience functions:
570 ** $_memeq(buf1, buf2, length)
571 ** $_streq(str1, str2)
573 ** $_regex(str, regex)
575 * The 'cd' command now defaults to using '~' (the home directory) if not
578 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
579 default for GCC since November 2000.
581 * The command 'forward-search' can now be abbreviated as 'fo'.
583 * The command 'info tracepoints' can now display 'installed on target'
584 or 'not installed on target' for each non-pending location of tracepoint.
586 * New configure options
588 --enable-libmcheck/--disable-libmcheck
589 By default, development versions are built with -lmcheck on hosts
590 that support it, in order to help track memory corruption issues.
591 Release versions, on the other hand, are built without -lmcheck
592 by default. The --enable-libmcheck/--disable-libmcheck configure
593 options allow the user to override that default.
594 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
595 This configure option allows the user to build GDB with
596 libbabeltrace using which GDB can read Common Trace Format data.
598 * New commands (for set/show, see "New options" below)
601 Catch signals. This is similar to "handle", but allows commands and
602 conditions to be attached.
605 List the BFDs known to GDB.
607 python-interactive [command]
609 Start a Python interactive prompt, or evaluate the optional command
610 and print the result of expressions.
613 "py" is a new alias for "python".
615 enable type-printer [name]...
616 disable type-printer [name]...
617 Enable or disable type printers.
621 ** For the Renesas Super-H architecture, the "regs" command has been removed
622 (has been deprecated in GDB 7.5), and "info all-registers" should be used
627 set print type methods (on|off)
628 show print type methods
629 Control whether method declarations are displayed by "ptype".
630 The default is to show them.
632 set print type typedefs (on|off)
633 show print type typedefs
634 Control whether typedef definitions are displayed by "ptype".
635 The default is to show them.
637 set filename-display basename|relative|absolute
638 show filename-display
639 Control the way in which filenames is displayed.
640 The default is "relative", which preserves previous behavior.
642 set trace-buffer-size
643 show trace-buffer-size
644 Request target to change the size of trace buffer.
646 set remote trace-buffer-size-packet auto|on|off
647 show remote trace-buffer-size-packet
648 Control the use of the remote protocol `QTBuffer:size' packet.
652 Control display of debugging messages related to ARM AArch64.
655 set debug coff-pe-read
656 show debug coff-pe-read
657 Control display of debugging messages related to reading of COFF/PE
662 Control display of debugging messages related to Mach-O symbols
665 set debug notification
666 show debug notification
667 Control display of debugging info for async remote notification.
671 ** Command parameter changes are now notified using new async record
672 "=cmd-param-changed".
673 ** Trace frame changes caused by command "tfind" are now notified using
674 new async record "=traceframe-changed".
675 ** The creation, deletion and modification of trace state variables
676 are now notified using new async records "=tsv-created",
677 "=tsv-deleted" and "=tsv-modified".
678 ** The start and stop of process record are now notified using new
679 async record "=record-started" and "=record-stopped".
680 ** Memory changes are now notified using new async record
682 ** The data-disassemble command response will include a "fullname" field
683 containing the absolute file name when source has been requested.
684 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
685 command, to allow pattern filling of memory areas.
686 ** New commands "-catch-load"/"-catch-unload" added for intercepting
687 library load/unload events.
688 ** The response to breakpoint commands and breakpoint async records
689 includes an "installed" field containing a boolean state about each
690 non-pending tracepoint location is whether installed on target or not.
691 ** Output of the "-trace-status" command includes a "trace-file" field
692 containing the name of the trace file being examined. This field is
693 optional, and only present when examining a trace file.
694 ** The "fullname" field is now always present along with the "file" field,
695 even if the file cannot be found by GDB.
697 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
698 You must have the LZMA library available when configuring GDB for this
699 feature to be enabled. For more information, see:
700 http://fedoraproject.org/wiki/Features/MiniDebugInfo
705 Set the size of trace buffer. The remote stub reports support for this
706 packet to gdb's qSupported query.
709 Enable Branch Trace Store (BTS)-based branch tracing for the current
710 thread. The remote stub reports support for this packet to gdb's
714 Disable branch tracing for the current thread. The remote stub reports
715 support for this packet to gdb's qSupported query.
718 Read the traced branches for the current thread. The remote stub
719 reports support for this packet to gdb's qSupported query.
721 *** Changes in GDB 7.5
723 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
724 for more x32 ABI info.
726 * GDB now supports access to MIPS DSP registers on Linux targets.
728 * GDB now supports debugging microMIPS binaries.
730 * The "info os" command on GNU/Linux can now display information on
731 several new classes of objects managed by the operating system:
732 "info os procgroups" lists process groups
733 "info os files" lists file descriptors
734 "info os sockets" lists internet-domain sockets
735 "info os shm" lists shared-memory regions
736 "info os semaphores" lists semaphores
737 "info os msg" lists message queues
738 "info os modules" lists loaded kernel modules
740 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
741 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
742 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
743 options and inspect the probe arguments using the new $_probe_arg family
744 of convenience variables. You can obtain more information about SystemTap
745 in <http://sourceware.org/systemtap/>.
747 * GDB now supports reversible debugging on ARM, it allows you to
748 debug basic ARM and THUMB instructions, and provides
749 record/replay support.
751 * The option "symbol-reloading" has been deleted as it is no longer used.
755 ** GDB commands implemented in Python can now be put in command class
758 ** The "maint set python print-stack on|off" is now deleted.
760 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
761 apply "flag enum"-style pretty-printing to any enum.
763 ** gdb.lookup_symbol can now work when there is no current frame.
765 ** gdb.Symbol now has a 'line' attribute, holding the line number in
766 the source at which the symbol was defined.
768 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
769 method 'value'. The former indicates whether the symbol needs a
770 frame in order to compute its value, and the latter computes the
773 ** A new method 'referenced_value' on gdb.Value objects which can
774 dereference pointer as well as C++ reference values.
776 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
777 which return the global and static blocks (as gdb.Block objects),
778 of the underlying symbol table, respectively.
780 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
781 object associated with a PC value.
783 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
784 of the address range occupied by code for the current source line.
786 * Go language support.
787 GDB now supports debugging programs written in the Go programming
790 * GDBserver now supports stdio connections.
791 E.g. (gdb) target remote | ssh myhost gdbserver - hello
793 * The binary "gdbtui" can no longer be built or installed.
794 Use "gdb -tui" instead.
796 * GDB will now print "flag" enums specially. A flag enum is one where
797 all the enumerator values have no bits in common when pairwise
798 "and"ed. When printing a value whose type is a flag enum, GDB will
799 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
800 (gdb) print (enum E) 3
803 * The filename part of a linespec will now match trailing components
804 of a source file name. For example, "break gcc/expr.c:1000" will
805 now set a breakpoint in build/gcc/expr.c, but not
808 * The "info proc" and "generate-core-file" commands will now also
809 work on remote targets connected to GDBserver on Linux.
811 * The command "info catch" has been removed. It has been disabled
814 * The "catch exception" and "catch assert" commands now accept
815 a condition at the end of the command, much like the "break"
816 command does. For instance:
818 (gdb) catch exception Constraint_Error if Barrier = True
820 Previously, it was possible to add a condition to such catchpoints,
821 but it had to be done as a second step, after the catchpoint had been
822 created, using the "condition" command.
824 * The "info static-tracepoint-marker" command will now also work on
825 native Linux targets with in-process agent.
827 * GDB can now set breakpoints on inlined functions.
829 * The .gdb_index section has been updated to include symbols for
830 inlined functions. GDB will ignore older .gdb_index sections by
831 default, which could cause symbol files to be loaded more slowly
832 until their .gdb_index sections can be recreated. The new command
833 "set use-deprecated-index-sections on" will cause GDB to use any older
834 .gdb_index sections it finds. This will restore performance, but the
835 ability to set breakpoints on inlined functions will be lost in symbol
836 files with older .gdb_index sections.
838 The .gdb_index section has also been updated to record more information
839 about each symbol. This speeds up the "info variables", "info functions"
840 and "info types" commands when used with programs having the .gdb_index
841 section, as well as speeding up debugging with shared libraries using
842 the .gdb_index section.
844 * Ada support for GDB/MI Variable Objects has been added.
846 * GDB can now support 'breakpoint always-inserted mode' in 'record'
851 ** New command -info-os is the MI equivalent of "info os".
853 ** Output logs ("set logging" and related) now include MI output.
857 ** "set use-deprecated-index-sections on|off"
858 "show use-deprecated-index-sections on|off"
859 Controls the use of deprecated .gdb_index sections.
861 ** "catch load" and "catch unload" can be used to stop when a shared
862 library is loaded or unloaded, respectively.
864 ** "enable count" can be used to auto-disable a breakpoint after
867 ** "info vtbl" can be used to show the virtual method tables for
868 C++ and Java objects.
870 ** "explore" and its sub commands "explore value" and "explore type"
871 can be used to recursively explore values and types of
872 expressions. These commands are available only if GDB is
873 configured with '--with-python'.
875 ** "info auto-load" shows status of all kinds of auto-loaded files,
876 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
877 sequences of commands files, "info auto-load python-scripts"
878 shows status of auto-loading Python script files,
879 "info auto-load local-gdbinit" shows status of loading init file
880 (.gdbinit) from current directory and "info auto-load libthread-db" shows
881 status of inferior specific thread debugging shared library loading.
883 ** "info auto-load-scripts", "set auto-load-scripts on|off"
884 and "show auto-load-scripts" commands have been deprecated, use their
885 "info auto-load python-scripts", "set auto-load python-scripts on|off"
886 and "show auto-load python-scripts" counterparts instead.
888 ** "dprintf location,format,args..." creates a dynamic printf, which
889 is basically a breakpoint that does a printf and immediately
890 resumes your program's execution, so it is like a printf that you
891 can insert dynamically at runtime instead of at compiletime.
893 ** "set print symbol"
895 Controls whether GDB attempts to display the symbol, if any,
896 corresponding to addresses it prints. This defaults to "on", but
897 you can set it to "off" to restore GDB's previous behavior.
899 * Deprecated commands
901 ** For the Renesas Super-H architecture, the "regs" command has been
902 deprecated, and "info all-registers" should be used instead.
906 Renesas RL78 rl78-*-elf
907 HP OpenVMS ia64 ia64-hp-openvms*
909 * GDBserver supports evaluation of breakpoint conditions. When
910 support is advertised by GDBserver, GDB may be told to send the
911 breakpoint conditions in bytecode form to GDBserver. GDBserver
912 will only report the breakpoint trigger to GDB when its condition
918 show mips compression
919 Select the compressed ISA encoding used in functions that have no symbol
920 information available. The encoding can be set to either of:
923 and is updated automatically from ELF file flags if available.
925 set breakpoint condition-evaluation
926 show breakpoint condition-evaluation
927 Control whether breakpoint conditions are evaluated by GDB ("host") or by
928 GDBserver ("target"). Default option "auto" chooses the most efficient
930 This option can improve debugger efficiency depending on the speed of the
934 Disable auto-loading globally.
937 Show auto-loading setting of all kinds of auto-loaded files.
939 set auto-load gdb-scripts on|off
940 show auto-load gdb-scripts
941 Control auto-loading of GDB canned sequences of commands files.
943 set auto-load python-scripts on|off
944 show auto-load python-scripts
945 Control auto-loading of Python script files.
947 set auto-load local-gdbinit on|off
948 show auto-load local-gdbinit
949 Control loading of init file (.gdbinit) from current directory.
951 set auto-load libthread-db on|off
952 show auto-load libthread-db
953 Control auto-loading of inferior specific thread debugging shared library.
955 set auto-load scripts-directory <dir1>[:<dir2>...]
956 show auto-load scripts-directory
957 Set a list of directories from which to load auto-loaded scripts.
958 Automatically loaded Python scripts and GDB scripts are located in one
959 of the directories listed by this option.
960 The delimiter (':' above) may differ according to the host platform.
962 set auto-load safe-path <dir1>[:<dir2>...]
963 show auto-load safe-path
964 Set a list of directories from which it is safe to auto-load files.
965 The delimiter (':' above) may differ according to the host platform.
967 set debug auto-load on|off
969 Control display of debugging info for auto-loading the files above.
971 set dprintf-style gdb|call|agent
973 Control the way in which a dynamic printf is performed; "gdb"
974 requests a GDB printf command, while "call" causes dprintf to call a
975 function in the inferior. "agent" requests that the target agent
976 (such as GDBserver) do the printing.
978 set dprintf-function <expr>
979 show dprintf-function
980 set dprintf-channel <expr>
982 Set the function and optional first argument to the call when using
983 the "call" style of dynamic printf.
985 set disconnected-dprintf on|off
986 show disconnected-dprintf
987 Control whether agent-style dynamic printfs continue to be in effect
988 after GDB disconnects.
990 * New configure options
993 Configure default value for the 'set auto-load scripts-directory'
994 setting above. It defaults to '$debugdir:$datadir/auto-load',
995 $debugdir representing global debugging info directories (available
996 via 'show debug-file-directory') and $datadir representing GDB's data
997 directory (available via 'show data-directory').
999 --with-auto-load-safe-path
1000 Configure default value for the 'set auto-load safe-path' setting
1001 above. It defaults to the --with-auto-load-dir setting.
1003 --without-auto-load-safe-path
1004 Set 'set auto-load safe-path' to '/', effectively disabling this
1007 * New remote packets
1009 z0/z1 conditional breakpoints extension
1011 The z0/z1 breakpoint insertion packets have been extended to carry
1012 a list of conditional expressions over to the remote stub depending on the
1013 condition evaluation mode. The use of this extension can be controlled
1014 via the "set remote conditional-breakpoints-packet" command.
1018 Specify the signals which the remote stub may pass to the debugged
1019 program without GDB involvement.
1021 * New command line options
1023 --init-command=FILE, -ix Like --command, -x but execute it
1024 before loading inferior.
1025 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1026 execute it before loading inferior.
1028 *** Changes in GDB 7.4
1030 * GDB now handles ambiguous linespecs more consistently; the existing
1031 FILE:LINE support has been expanded to other types of linespecs. A
1032 breakpoint will now be set on all matching locations in all
1033 inferiors, and locations will be added or removed according to
1036 * GDB now allows you to skip uninteresting functions and files when
1037 stepping with the "skip function" and "skip file" commands.
1039 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1040 and "show remote hardware-watchpoint-length-limit". These allows to
1041 set or show the maximum length limit (in bytes) of a remote
1042 target hardware watchpoint.
1044 This allows e.g. to use "unlimited" hardware watchpoints with the
1045 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1046 watchpoints are slower than real hardware watchpoints but are
1047 significantly faster than gdb software watchpoints.
1051 ** The register_pretty_printer function in module gdb.printing now takes
1052 an optional `replace' argument. If True, the new printer replaces any
1055 ** The "maint set python print-stack on|off" command has been
1056 deprecated and will be deleted in GDB 7.5.
1057 A new command: "set python print-stack none|full|message" has
1058 replaced it. Additionally, the default for "print-stack" is
1059 now "message", which just prints the error message without
1062 ** A prompt substitution hook (prompt_hook) is now available to the
1065 ** A new Python module, gdb.prompt has been added to the GDB Python
1066 modules library. This module provides functionality for
1067 escape sequences in prompts (used by set/show
1068 extended-prompt). These escape sequences are replaced by their
1069 corresponding value.
1071 ** Python commands and convenience-functions located in
1072 'data-directory'/python/gdb/command and
1073 'data-directory'/python/gdb/function are now automatically loaded
1076 ** Blocks now provide four new attributes. global_block and
1077 static_block will return the global and static blocks
1078 respectively. is_static and is_global are boolean attributes
1079 that indicate if the block is one of those two types.
1081 ** Symbols now provide the "type" attribute, the type of the symbol.
1083 ** The "gdb.breakpoint" function has been deprecated in favor of
1086 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1087 of a function. This class is based on the "finish" command
1088 available in the CLI.
1090 ** Type objects for struct and union types now allow access to
1091 the fields using standard Python dictionary (mapping) methods.
1092 For example, "some_type['myfield']" now works, as does
1093 "some_type.items()".
1095 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1098 ** A new function, "deep_items" has been added to the gdb.types
1099 module in the GDB Python modules library. This function returns
1100 an iterator over the fields of a struct or union type. Unlike
1101 the standard Python "iteritems" method, it will recursively traverse
1102 any anonymous fields.
1106 ** "*stopped" events can report several new "reason"s, such as
1109 ** Breakpoint changes are now notified using new async records, like
1110 "=breakpoint-modified".
1112 ** New command -ada-task-info.
1114 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1115 $sdir specifies the default system locations of shared libraries.
1116 $pdir specifies the directory where the libpthread used by the application
1119 GDB no longer looks in $sdir and $pdir after it has searched the directories
1120 mentioned in libthread-db-search-path. If you want to search those
1121 directories, they must be specified in libthread-db-search-path.
1122 The default value of libthread-db-search-path on GNU/Linux and Solaris
1123 systems is now "$sdir:$pdir".
1125 $pdir is not supported by gdbserver, it is currently ignored.
1126 $sdir is supported by gdbserver.
1128 * New configure option --with-iconv-bin.
1129 When using the internationalization support like the one in the GNU C
1130 library, GDB will invoke the "iconv" program to get a list of supported
1131 character sets. If this program lives in a non-standard location, one can
1132 use this option to specify where to find it.
1134 * When natively debugging programs on PowerPC BookE processors running
1135 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1136 watchpoints, which specify a mask in addition to an address to watch.
1137 The mask specifies that some bits of an address (the bits which are
1138 reset in the mask) should be ignored when matching the address accessed
1139 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1140 section in the user manual for more details.
1142 * The new option --once causes GDBserver to stop listening for connections once
1143 the first connection is made. The listening port used by GDBserver will
1144 become available after that.
1146 * New commands "info macros" and "alias" have been added.
1148 * New function parameters suffix @entry specifies value of function parameter
1149 at the time the function got called. Entry values are available only since
1155 "!" is now an alias of the "shell" command.
1156 Note that no space is needed between "!" and SHELL COMMAND.
1160 watch EXPRESSION mask MASK_VALUE
1161 The watch command now supports the mask argument which allows creation
1162 of masked watchpoints, if the current architecture supports this feature.
1164 info auto-load-scripts [REGEXP]
1165 This command was formerly named "maintenance print section-scripts".
1166 It is now generally useful and is no longer a maintenance-only command.
1168 info macro [-all] [--] MACRO
1169 The info macro command has new options `-all' and `--'. The first for
1170 printing all definitions of a macro. The second for explicitly specifying
1171 the end of arguments and the beginning of the macro name in case the macro
1172 name starts with a hyphen.
1174 collect[/s] EXPRESSIONS
1175 The tracepoint collect command now takes an optional modifier "/s"
1176 that directs it to dereference pointer-to-character types and
1177 collect the bytes of memory up to a zero byte. The behavior is
1178 similar to what you see when you use the regular print command on a
1179 string. An optional integer following the "/s" sets a bound on the
1180 number of bytes that will be collected.
1183 The trace start command now interprets any supplied arguments as a
1184 note to be recorded with the trace run, with an effect similar to
1185 setting the variable trace-notes.
1188 The trace stop command now interprets any arguments as a note to be
1189 mentioned along with the tstatus report that the trace was stopped
1190 with a command. The effect is similar to setting the variable
1193 * Tracepoints can now be enabled and disabled at any time after a trace
1194 experiment has been started using the standard "enable" and "disable"
1195 commands. It is now possible to start a trace experiment with no enabled
1196 tracepoints; GDB will display a warning, but will allow the experiment to
1197 begin, assuming that tracepoints will be enabled as needed while the trace
1200 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1201 locations with 4-byte instructions, when they were previously
1202 limited to locations with instructions of 5 bytes or longer.
1206 set debug dwarf2-read
1207 show debug dwarf2-read
1208 Turns on or off display of debugging messages related to reading
1209 DWARF debug info. The default is off.
1211 set debug symtab-create
1212 show debug symtab-create
1213 Turns on or off display of debugging messages related to symbol table
1214 creation. The default is off.
1217 show extended-prompt
1218 Set the GDB prompt, and allow escape sequences to be inserted to
1219 display miscellaneous information (see 'help set extended-prompt'
1220 for the list of sequences). This prompt (and any information
1221 accessed through the escape sequences) is updated every time the
1222 prompt is displayed.
1224 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1225 show print entry-values
1226 Set printing of frame argument values at function entry. In some cases
1227 GDB can determine the value of function argument which was passed by the
1228 function caller, even if the value was modified inside the called function.
1230 set debug entry-values
1231 show debug entry-values
1232 Control display of debugging info for determining frame argument values at
1233 function entry and virtual tail call frames.
1235 set basenames-may-differ
1236 show basenames-may-differ
1237 Set whether a source file may have multiple base names.
1238 (A "base name" is the name of a file with the directory part removed.
1239 Example: The base name of "/home/user/hello.c" is "hello.c".)
1240 If set, GDB will canonicalize file names (e.g., expand symlinks)
1241 before comparing them. Canonicalization is an expensive operation,
1242 but it allows the same file be known by more than one base name.
1243 If not set (the default), all source files are assumed to have just
1244 one base name, and gdb will do file name comparisons more efficiently.
1250 Set a user name and notes for the current and any future trace runs.
1251 This is useful for long-running and/or disconnected traces, to
1252 inform others (or yourself) as to who is running the trace, supply
1253 contact information, or otherwise explain what is going on.
1255 set trace-stop-notes
1256 show trace-stop-notes
1257 Set a note attached to the trace run, that is displayed when the
1258 trace has been stopped by a tstop command. This is useful for
1259 instance as an explanation, if you are stopping a trace run that was
1260 started by someone else.
1262 * New remote packets
1266 Dynamically enable a tracepoint in a started trace experiment.
1270 Dynamically disable a tracepoint in a started trace experiment.
1274 Set the user and notes of the trace run.
1278 Query the current status of a tracepoint.
1282 Query the minimum length of instruction at which a fast tracepoint may
1285 * Dcache size (number of lines) and line-size are now runtime-configurable
1286 via "set dcache line" and "set dcache line-size" commands.
1290 Texas Instruments TMS320C6x tic6x-*-*
1294 Renesas RL78 rl78-*-elf
1296 *** Changes in GDB 7.3.1
1298 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1300 *** Changes in GDB 7.3
1302 * GDB has a new command: "thread find [REGEXP]".
1303 It finds the thread id whose name, target id, or thread extra info
1304 matches the given regular expression.
1306 * The "catch syscall" command now works on mips*-linux* targets.
1308 * The -data-disassemble MI command now supports modes 2 and 3 for
1309 dumping the instruction opcodes.
1311 * New command line options
1313 -data-directory DIR Specify DIR as the "data-directory".
1314 This is mostly for testing purposes.
1316 * The "maint set python auto-load on|off" command has been renamed to
1317 "set auto-load-scripts on|off".
1319 * GDB has a new command: "set directories".
1320 It is like the "dir" command except that it replaces the
1321 source path list instead of augmenting it.
1323 * GDB now understands thread names.
1325 On GNU/Linux, "info threads" will display the thread name as set by
1326 prctl or pthread_setname_np.
1328 There is also a new command, "thread name", which can be used to
1329 assign a name internally for GDB to display.
1332 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1333 has been integrated into GDB.
1337 ** The function gdb.Write now accepts an optional keyword 'stream'.
1338 This keyword, when provided, will direct the output to either
1339 stdout, stderr, or GDB's logging output.
1341 ** Parameters can now be be sub-classed in Python, and in particular
1342 you may implement the get_set_doc and get_show_doc functions.
1343 This improves how Parameter set/show documentation is processed
1344 and allows for more dynamic content.
1346 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1347 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1348 have an is_valid method.
1350 ** Breakpoints can now be sub-classed in Python, and in particular
1351 you may implement a 'stop' function that is executed each time
1352 the inferior reaches that breakpoint.
1354 ** New function gdb.lookup_global_symbol looks up a global symbol.
1356 ** GDB values in Python are now callable if the value represents a
1357 function. For example, if 'some_value' represents a function that
1358 takes two integer parameters and returns a value, you can call
1359 that function like so:
1361 result = some_value (10,20)
1363 ** Module gdb.types has been added.
1364 It contains a collection of utilities for working with gdb.Types objects:
1365 get_basic_type, has_field, make_enum_dict.
1367 ** Module gdb.printing has been added.
1368 It contains utilities for writing and registering pretty-printers.
1369 New classes: PrettyPrinter, SubPrettyPrinter,
1370 RegexpCollectionPrettyPrinter.
1371 New function: register_pretty_printer.
1373 ** New commands "info pretty-printers", "enable pretty-printer" and
1374 "disable pretty-printer" have been added.
1376 ** gdb.parameter("directories") is now available.
1378 ** New function gdb.newest_frame returns the newest frame in the
1381 ** The gdb.InferiorThread class has a new "name" attribute. This
1382 holds the thread's name.
1384 ** Python Support for Inferior events.
1385 Python scripts can add observers to be notified of events
1386 occurring in the process being debugged.
1387 The following events are currently supported:
1388 - gdb.events.cont Continue event.
1389 - gdb.events.exited Inferior exited event.
1390 - gdb.events.stop Signal received, and Breakpoint hit events.
1394 ** GDB now puts template parameters in scope when debugging in an
1395 instantiation. For example, if you have:
1397 template<int X> int func (void) { return X; }
1399 then if you step into func<5>, "print X" will show "5". This
1400 feature requires proper debuginfo support from the compiler; it
1401 was added to GCC 4.5.
1403 ** The motion commands "next", "finish", "until", and "advance" now
1404 work better when exceptions are thrown. In particular, GDB will
1405 no longer lose control of the inferior; instead, the GDB will
1406 stop the inferior at the point at which the exception is caught.
1407 This functionality requires a change in the exception handling
1408 code that was introduced in GCC 4.5.
1410 * GDB now follows GCC's rules on accessing volatile objects when
1411 reading or writing target state during expression evaluation.
1412 One notable difference to prior behavior is that "print x = 0"
1413 no longer generates a read of x; the value of the assignment is
1414 now always taken directly from the value being assigned.
1416 * GDB now has some support for using labels in the program's source in
1417 linespecs. For instance, you can use "advance label" to continue
1418 execution to a label.
1420 * GDB now has support for reading and writing a new .gdb_index
1421 section. This section holds a fast index of DWARF debugging
1422 information and can be used to greatly speed up GDB startup and
1423 operation. See the documentation for `save gdb-index' for details.
1425 * The "watch" command now accepts an optional "-location" argument.
1426 When used, this causes GDB to watch the memory referred to by the
1427 expression. Such a watchpoint is never deleted due to it going out
1430 * GDB now supports thread debugging of core dumps on GNU/Linux.
1432 GDB now activates thread debugging using the libthread_db library
1433 when debugging GNU/Linux core dumps, similarly to when debugging
1434 live processes. As a result, when debugging a core dump file, GDB
1435 is now able to display pthread_t ids of threads. For example, "info
1436 threads" shows the same output as when debugging the process when it
1437 was live. In earlier releases, you'd see something like this:
1440 * 1 LWP 6780 main () at main.c:10
1442 While now you see this:
1445 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1447 It is also now possible to inspect TLS variables when debugging core
1450 When debugging a core dump generated on a machine other than the one
1451 used to run GDB, you may need to point GDB at the correct
1452 libthread_db library with the "set libthread-db-search-path"
1453 command. See the user manual for more details on this command.
1455 * When natively debugging programs on PowerPC BookE processors running
1456 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1457 which stop execution of the inferior whenever it executes an instruction
1458 at any address within the specified range. See the "PowerPC Embedded"
1459 section in the user manual for more details.
1461 * New features in the GDB remote stub, GDBserver
1463 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1464 and i686 LynxOS (version 5.x).
1466 ** GDBserver is now supported on Blackfin Linux.
1468 * New native configurations
1470 ia64 HP-UX ia64-*-hpux*
1474 Analog Devices, Inc. Blackfin Processor bfin-*
1476 * Ada task switching is now supported on sparc-elf targets when
1477 debugging a program using the Ravenscar Profile. For more information,
1478 see the "Tasking Support when using the Ravenscar Profile" section
1479 in the GDB user manual.
1481 * Guile support was removed.
1483 * New features in the GNU simulator
1485 ** The --map-info flag lists all known core mappings.
1487 ** CFI flashes may be simulated via the "cfi" device.
1489 *** Changes in GDB 7.2
1491 * Shared library support for remote targets by default
1493 When GDB is configured for a generic, non-OS specific target, like
1494 for example, --target=arm-eabi or one of the many *-*-elf targets,
1495 GDB now queries remote stubs for loaded shared libraries using the
1496 `qXfer:libraries:read' packet. Previously, shared library support
1497 was always disabled for such configurations.
1501 ** Argument Dependent Lookup (ADL)
1503 In C++ ADL lookup directs function search to the namespaces of its
1504 arguments even if the namespace has not been imported.
1514 Here the compiler will search for `foo' in the namespace of 'b'
1515 and find A::foo. GDB now supports this. This construct is commonly
1516 used in the Standard Template Library for operators.
1518 ** Improved User Defined Operator Support
1520 In addition to member operators, GDB now supports lookup of operators
1521 defined in a namespace and imported with a `using' directive, operators
1522 defined in the global scope, operators imported implicitly from an
1523 anonymous namespace, and the ADL operators mentioned in the previous
1525 GDB now also supports proper overload resolution for all the previously
1526 mentioned flavors of operators.
1528 ** static const class members
1530 Printing of static const class members that are initialized in the
1531 class definition has been fixed.
1533 * Windows Thread Information Block access.
1535 On Windows targets, GDB now supports displaying the Windows Thread
1536 Information Block (TIB) structure. This structure is visible either
1537 by using the new command `info w32 thread-information-block' or, by
1538 dereferencing the new convenience variable named `$_tlb', a
1539 thread-specific pointer to the TIB. This feature is also supported
1540 when remote debugging using GDBserver.
1542 * Static tracepoints
1544 Static tracepoints are calls in the user program into a tracing
1545 library. One such library is a port of the LTTng kernel tracer to
1546 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1547 When debugging with GDBserver, GDB now supports combining the GDB
1548 tracepoint machinery with such libraries. For example: the user can
1549 use GDB to probe a static tracepoint marker (a call from the user
1550 program into the tracing library) with the new "strace" command (see
1551 "New commands" below). This creates a "static tracepoint" in the
1552 breakpoint list, that can be manipulated with the same feature set
1553 as fast and regular tracepoints. E.g., collect registers, local and
1554 global variables, collect trace state variables, and define
1555 tracepoint conditions. In addition, the user can collect extra
1556 static tracepoint marker specific data, by collecting the new
1557 $_sdata internal variable. When analyzing the trace buffer, you can
1558 inspect $_sdata like any other variable available to GDB. For more
1559 information, see the "Tracepoints" chapter in GDB user manual. New
1560 remote packets have been defined to support static tracepoints, see
1561 the "New remote packets" section below.
1563 * Better reconstruction of tracepoints after disconnected tracing
1565 GDB will attempt to download the original source form of tracepoint
1566 definitions when starting a trace run, and then will upload these
1567 upon reconnection to the target, resulting in a more accurate
1568 reconstruction of the tracepoints that are in use on the target.
1572 You can now exercise direct control over the ways that GDB can
1573 affect your program. For instance, you can disallow the setting of
1574 breakpoints, so that the program can run continuously (assuming
1575 non-stop mode). In addition, the "observer" variable is available
1576 to switch all of the different controls; in observer mode, GDB
1577 cannot affect the target's behavior at all, which is useful for
1578 tasks like diagnosing live systems in the field.
1580 * The new convenience variable $_thread holds the number of the
1583 * New remote packets
1587 Return the address of the Windows Thread Information Block of a given thread.
1591 In response to several of the tracepoint packets, the target may now
1592 also respond with a number of intermediate `qRelocInsn' request
1593 packets before the final result packet, to have GDB handle
1594 relocating an instruction to execute at a different address. This
1595 is particularly useful for stubs that support fast tracepoints. GDB
1596 reports support for this feature in the qSupported packet.
1600 List static tracepoint markers in the target program.
1604 List static tracepoint markers at a given address in the target
1607 qXfer:statictrace:read
1609 Read the static trace data collected (by a `collect $_sdata'
1610 tracepoint action). The remote stub reports support for this packet
1611 to gdb's qSupported query.
1615 Send the current settings of GDB's permission flags.
1619 Send part of the source (textual) form of a tracepoint definition,
1620 which includes location, conditional, and action list.
1622 * The source command now accepts a -s option to force searching for the
1623 script in the source search path even if the script name specifies
1626 * New features in the GDB remote stub, GDBserver
1628 - GDBserver now support tracepoints (including fast tracepoints, and
1629 static tracepoints). The feature is currently supported by the
1630 i386-linux and amd64-linux builds. See the "Tracepoints support
1631 in gdbserver" section in the manual for more information.
1633 GDBserver JIT compiles the tracepoint's conditional agent
1634 expression bytecode into native code whenever possible for low
1635 overhead dynamic tracepoints conditionals. For such tracepoints,
1636 an expression that examines program state is evaluated when the
1637 tracepoint is reached, in order to determine whether to capture
1638 trace data. If the condition is simple and false, processing the
1639 tracepoint finishes very quickly and no data is gathered.
1641 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1642 for static tracepoints support.
1644 - GDBserver now supports x86_64 Windows 64-bit debugging.
1646 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1647 it understands register description.
1649 * The --batch flag now disables pagination and queries.
1651 * X86 general purpose registers
1653 GDB now supports reading/writing byte, word and double-word x86
1654 general purpose registers directly. This means you can use, say,
1655 $ah or $ax to refer, respectively, to the byte register AH and
1656 16-bit word register AX that are actually portions of the 32-bit
1657 register EAX or 64-bit register RAX.
1659 * The `commands' command now accepts a range of breakpoints to modify.
1660 A plain `commands' following a command that creates multiple
1661 breakpoints affects all the breakpoints set by that command. This
1662 applies to breakpoints set by `rbreak', and also applies when a
1663 single `break' command creates multiple breakpoints (e.g.,
1664 breakpoints on overloaded c++ functions).
1666 * The `rbreak' command now accepts a filename specification as part of
1667 its argument, limiting the functions selected by the regex to those
1668 in the specified file.
1670 * Support for remote debugging Windows and SymbianOS shared libraries
1671 from Unix hosts has been improved. Non Windows GDB builds now can
1672 understand target reported file names that follow MS-DOS based file
1673 system semantics, such as file names that include drive letters and
1674 use the backslash character as directory separator. This makes it
1675 possible to transparently use the "set sysroot" and "set
1676 solib-search-path" on Unix hosts to point as host copies of the
1677 target's shared libraries. See the new command "set
1678 target-file-system-kind" described below, and the "Commands to
1679 specify files" section in the user manual for more information.
1683 eval template, expressions...
1684 Convert the values of one or more expressions under the control
1685 of the string template to a command line, and call it.
1687 set target-file-system-kind unix|dos-based|auto
1688 show target-file-system-kind
1689 Set or show the assumed file system kind for target reported file
1692 save breakpoints <filename>
1693 Save all current breakpoint definitions to a file suitable for use
1694 in a later debugging session. To read the saved breakpoint
1695 definitions, use the `source' command.
1697 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1700 info static-tracepoint-markers
1701 Display information about static tracepoint markers in the target.
1703 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1704 Define a static tracepoint by probing a marker at the given
1705 function, line, address, or marker ID.
1709 Enable and disable observer mode.
1711 set may-write-registers on|off
1712 set may-write-memory on|off
1713 set may-insert-breakpoints on|off
1714 set may-insert-tracepoints on|off
1715 set may-insert-fast-tracepoints on|off
1716 set may-interrupt on|off
1717 Set individual permissions for GDB effects on the target. Note that
1718 some of these settings can have undesirable or surprising
1719 consequences, particularly when changed in the middle of a session.
1720 For instance, disabling the writing of memory can prevent
1721 breakpoints from being inserted, cause single-stepping to fail, or
1722 even crash your program, if you disable after breakpoints have been
1723 inserted. However, GDB should not crash.
1725 set record memory-query on|off
1726 show record memory-query
1727 Control whether to stop the inferior if memory changes caused
1728 by an instruction cannot be recorded.
1733 The disassemble command now supports "start,+length" form of two arguments.
1737 ** GDB now provides a new directory location, called the python directory,
1738 where Python scripts written for GDB can be installed. The location
1739 of that directory is <data-directory>/python, where <data-directory>
1740 is the GDB data directory. For more details, see section `Scripting
1741 GDB using Python' in the manual.
1743 ** The GDB Python API now has access to breakpoints, symbols, symbol
1744 tables, program spaces, inferiors, threads and frame's code blocks.
1745 Additionally, GDB Parameters can now be created from the API, and
1746 manipulated via set/show in the CLI.
1748 ** New functions gdb.target_charset, gdb.target_wide_charset,
1749 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1751 ** New exception gdb.GdbError.
1753 ** Pretty-printers are now also looked up in the current program space.
1755 ** Pretty-printers can now be individually enabled and disabled.
1757 ** GDB now looks for names of Python scripts to auto-load in a
1758 special section named `.debug_gdb_scripts', in addition to looking
1759 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1761 * Tracepoint actions were unified with breakpoint commands. In particular,
1762 there are no longer differences in "info break" output for breakpoints and
1763 tracepoints and the "commands" command can be used for both tracepoints and
1764 regular breakpoints.
1768 ARM Symbian arm*-*-symbianelf*
1770 * D language support.
1771 GDB now supports debugging programs written in the D programming
1774 * GDB now supports the extended ptrace interface for PowerPC which is
1775 available since Linux kernel version 2.6.34. This automatically enables
1776 any hardware breakpoints and additional hardware watchpoints available in
1777 the processor. The old ptrace interface exposes just one hardware
1778 watchpoint and no hardware breakpoints.
1780 * GDB is now able to use the Data Value Compare (DVC) register available on
1781 embedded PowerPC processors to implement in hardware simple watchpoint
1782 conditions of the form:
1784 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1786 This works in native GDB running on Linux kernels with the extended ptrace
1787 interface mentioned above.
1789 *** Changes in GDB 7.1
1793 ** Namespace Support
1795 GDB now supports importing of namespaces in C++. This enables the
1796 user to inspect variables from imported namespaces. Support for
1797 namepace aliasing has also been added. So, if a namespace is
1798 aliased in the current scope (e.g. namepace C=A; ) the user can
1799 print variables using the alias (e.g. (gdb) print C::x).
1803 All known bugs relating to the printing of virtual base class were
1804 fixed. It is now possible to call overloaded static methods using a
1809 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1810 and reinterpret_cast<> are now handled by the C++ expression parser.
1814 Xilinx MicroBlaze microblaze-*-*
1819 Xilinx MicroBlaze microblaze
1822 * Multi-program debugging.
1824 GDB now has support for multi-program (a.k.a. multi-executable or
1825 multi-exec) debugging. This allows for debugging multiple inferiors
1826 simultaneously each running a different program under the same GDB
1827 session. See "Debugging Multiple Inferiors and Programs" in the
1828 manual for more information. This implied some user visible changes
1829 in the multi-inferior support. For example, "info inferiors" now
1830 lists inferiors that are not running yet or that have exited
1831 already. See also "New commands" and "New options" below.
1833 * New tracing features
1835 GDB's tracepoint facility now includes several new features:
1837 ** Trace state variables
1839 GDB tracepoints now include support for trace state variables, which
1840 are variables managed by the target agent during a tracing
1841 experiment. They are useful for tracepoints that trigger each
1842 other, so for instance one tracepoint can count hits in a variable,
1843 and then a second tracepoint has a condition that is true when the
1844 count reaches a particular value. Trace state variables share the
1845 $-syntax of GDB convenience variables, and can appear in both
1846 tracepoint actions and condition expressions. Use the "tvariable"
1847 command to create, and "info tvariables" to view; see "Trace State
1848 Variables" in the manual for more detail.
1852 GDB now includes an option for defining fast tracepoints, which
1853 targets may implement more efficiently, such as by installing a jump
1854 into the target agent rather than a trap instruction. The resulting
1855 speedup can be by two orders of magnitude or more, although the
1856 tradeoff is that some program locations on some target architectures
1857 might not allow fast tracepoint installation, for instance if the
1858 instruction to be replaced is shorter than the jump. To request a
1859 fast tracepoint, use the "ftrace" command, with syntax identical to
1860 the regular trace command.
1862 ** Disconnected tracing
1864 It is now possible to detach GDB from the target while it is running
1865 a trace experiment, then reconnect later to see how the experiment
1866 is going. In addition, a new variable disconnected-tracing lets you
1867 tell the target agent whether to continue running a trace if the
1868 connection is lost unexpectedly.
1872 GDB now has the ability to save the trace buffer into a file, and
1873 then use that file as a target, similarly to you can do with
1874 corefiles. You can select trace frames, print data that was
1875 collected in them, and use tstatus to display the state of the
1876 tracing run at the moment that it was saved. To create a trace
1877 file, use "tsave <filename>", and to use it, do "target tfile
1880 ** Circular trace buffer
1882 You can ask the target agent to handle the trace buffer as a
1883 circular buffer, discarding the oldest trace frames to make room for
1884 newer ones, by setting circular-trace-buffer to on. This feature may
1885 not be available for all target agents.
1890 The disassemble command, when invoked with two arguments, now requires
1891 the arguments to be comma-separated.
1894 The info variables command now displays variable definitions. Files
1895 which only declare a variable are not shown.
1898 The source command is now capable of sourcing Python scripts.
1899 This feature is dependent on the debugger being build with Python
1902 Related to this enhancement is also the introduction of a new command
1903 "set script-extension" (see below).
1905 * New commands (for set/show, see "New options" below)
1907 record save [<FILENAME>]
1908 Save a file (in core file format) containing the process record
1909 execution log for replay debugging at a later time.
1911 record restore <FILENAME>
1912 Restore the process record execution log that was saved at an
1913 earlier time, for replay debugging.
1915 add-inferior [-copies <N>] [-exec <FILENAME>]
1918 clone-inferior [-copies <N>] [ID]
1919 Make a new inferior ready to execute the same program another
1920 inferior has loaded.
1925 maint info program-spaces
1926 List the program spaces loaded into GDB.
1928 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1929 show remote interrupt-sequence
1930 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1931 as the sequence to the remote target in order to interrupt the execution.
1932 Ctrl-C is a default. Some system prefers BREAK which is high level of
1933 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1934 Magic SysRq g. It is BREAK signal and character 'g'.
1936 set remote interrupt-on-connect [on | off]
1937 show remote interrupt-on-connect
1938 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1939 remote target when gdb connects to it. This is needed when you debug
1942 set remotebreak [on | off]
1944 Deprecated. Use "set/show remote interrupt-sequence" instead.
1946 tvariable $NAME [ = EXP ]
1947 Create or modify a trace state variable.
1950 List trace state variables and their values.
1952 delete tvariable $NAME ...
1953 Delete one or more trace state variables.
1956 Evaluate the given expressions without collecting anything into the
1957 trace buffer. (Valid in tracepoint actions only.)
1959 ftrace FN / FILE:LINE / *ADDR
1960 Define a fast tracepoint at the given function, line, or address.
1962 * New expression syntax
1964 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1965 GDB now parses 0b101010 identically with 42.
1969 set follow-exec-mode new|same
1970 show follow-exec-mode
1971 Control whether GDB reuses the same inferior across an exec call or
1972 creates a new one. This is useful to be able to restart the old
1973 executable after the inferior having done an exec call.
1975 set default-collect EXPR, ...
1976 show default-collect
1977 Define a list of expressions to be collected at each tracepoint.
1978 This is a useful way to ensure essential items are not overlooked,
1979 such as registers or a critical global variable.
1981 set disconnected-tracing
1982 show disconnected-tracing
1983 If set to 1, the target is instructed to continue tracing if it
1984 loses its connection to GDB. If 0, the target is to stop tracing
1987 set circular-trace-buffer
1988 show circular-trace-buffer
1989 If set to on, the target is instructed to use a circular trace buffer
1990 and discard the oldest trace frames instead of stopping the trace due
1991 to a full trace buffer. If set to off, the trace stops when the buffer
1992 fills up. Some targets may not support this.
1994 set script-extension off|soft|strict
1995 show script-extension
1996 If set to "off", the debugger does not perform any script language
1997 recognition, and all sourced files are assumed to be GDB scripts.
1998 If set to "soft" (the default), files are sourced according to
1999 filename extension, falling back to GDB scripts if the first
2001 If set to "strict", files are sourced according to filename extension.
2003 set ada trust-PAD-over-XVS on|off
2004 show ada trust-PAD-over-XVS
2005 If off, activate a workaround against a bug in the debugging information
2006 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2007 the GCC sources for more information about the GNAT encoding and
2008 PAD types in particular). It is always safe to set this option to
2009 off, but this introduces a slight performance penalty. The default
2012 * Python API Improvements
2014 ** GDB provides the new class gdb.LazyString. This is useful in
2015 some pretty-printing cases. The new method gdb.Value.lazy_string
2016 provides a simple way to create objects of this type.
2018 ** The fields returned by gdb.Type.fields now have an
2019 `is_base_class' attribute.
2021 ** The new method gdb.Type.range returns the range of an array type.
2023 ** The new method gdb.parse_and_eval can be used to parse and
2024 evaluate an expression.
2026 * New remote packets
2029 Define a trace state variable.
2032 Get the current value of a trace state variable.
2035 Set desired tracing behavior upon disconnection.
2038 Set the trace buffer to be linear or circular.
2041 Get data about the tracepoints currently in use.
2045 Process record now works correctly with hardware watchpoints.
2047 Multiple bug fixes have been made to the mips-irix port, making it
2048 much more reliable. In particular:
2049 - Debugging threaded applications is now possible again. Previously,
2050 GDB would hang while starting the program, or while waiting for
2051 the program to stop at a breakpoint.
2052 - Attaching to a running process no longer hangs.
2053 - An error occurring while loading a core file has been fixed.
2054 - Changing the value of the PC register now works again. This fixes
2055 problems observed when using the "jump" command, or when calling
2056 a function from GDB, or even when assigning a new value to $pc.
2057 - With the "finish" and "return" commands, the return value for functions
2058 returning a small array is now correctly printed.
2059 - It is now possible to break on shared library code which gets executed
2060 during a shared library init phase (code executed while executing
2061 their .init section). Previously, the breakpoint would have no effect.
2062 - GDB is now able to backtrace through the signal handler for
2063 non-threaded programs.
2065 PIE (Position Independent Executable) programs debugging is now supported.
2066 This includes debugging execution of PIC (Position Independent Code) shared
2067 libraries although for that, it should be possible to run such libraries as an
2070 *** Changes in GDB 7.0
2072 * GDB now has an interface for JIT compilation. Applications that
2073 dynamically generate code can create symbol files in memory and register
2074 them with GDB. For users, the feature should work transparently, and
2075 for JIT developers, the interface is documented in the GDB manual in the
2076 "JIT Compilation Interface" chapter.
2078 * Tracepoints may now be conditional. The syntax is as for
2079 breakpoints; either an "if" clause appended to the "trace" command,
2080 or the "condition" command is available. GDB sends the condition to
2081 the target for evaluation using the same bytecode format as is used
2082 for tracepoint actions.
2084 * The disassemble command now supports: an optional /r modifier, print the
2085 raw instructions in hex as well as in symbolic form, and an optional /m
2086 modifier to print mixed source+assembly.
2088 * Process record and replay
2090 In a architecture environment that supports ``process record and
2091 replay'', ``process record and replay'' target can record a log of
2092 the process execution, and replay it with both forward and reverse
2095 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2096 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2097 set execution-direction {forward|reverse}, for targets that support
2100 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2101 feature is available with a native GDB running on kernel version
2104 * GDB now has support for multi-byte and wide character sets on the
2105 target. Strings whose character type is wchar_t, char16_t, or
2106 char32_t are now correctly printed. GDB supports wide- and unicode-
2107 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2108 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2109 `printf'. This feature requires iconv to work properly; if your
2110 system does not have a working iconv, GDB can use GNU libiconv. See
2111 the installation instructions for more information.
2113 * GDB now supports automatic retrieval of shared library files from
2114 remote targets. To use this feature, specify a system root that begins
2115 with the `remote:' prefix, either via the `set sysroot' command or via
2116 the `--with-sysroot' configure-time option.
2118 * "info sharedlibrary" now takes an optional regex of libraries to show,
2119 and it now reports if a shared library has no debugging information.
2121 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2122 now complete on file names.
2124 * When completing in expressions, gdb will attempt to limit
2125 completions to allowable structure or union fields, where appropriate.
2126 For instance, consider:
2128 # struct example { int f1; double f2; };
2129 # struct example variable;
2132 If the user types TAB at the end of this command line, the available
2133 completions will be "f1" and "f2".
2135 * Inlined functions are now supported. They show up in backtraces, and
2136 the "step", "next", and "finish" commands handle them automatically.
2138 * GDB now supports the token-splicing (##) and stringification (#)
2139 operators when expanding macros. It also supports variable-arity
2142 * GDB now supports inspecting extra signal information, exported by
2143 the new $_siginfo convenience variable. The feature is currently
2144 implemented on linux ARM, i386 and amd64.
2146 * GDB can now display the VFP floating point registers and NEON vector
2147 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2148 can provide these registers (requires Linux 2.6.30 or later). Remote
2149 and simulator targets may also provide them.
2151 * New remote packets
2154 Search memory for a sequence of bytes.
2157 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2158 operation over reliable transport links. Use of this packet is
2159 controlled by the `set remote noack-packet' command.
2162 Kill the process with the specified process ID. Use this in preference
2163 to `k' when multiprocess protocol extensions are supported.
2166 Obtains additional operating system information
2170 Read or write additional signal information.
2172 * Removed remote protocol undocumented extension
2174 An undocumented extension to the remote protocol's `S' stop reply
2175 packet that permited the stub to pass a process id was removed.
2176 Remote servers should use the `T' stop reply packet instead.
2178 * GDB now supports multiple function calling conventions according to the
2179 DWARF-2 DW_AT_calling_convention function attribute.
2181 * The SH target utilizes the aforementioned change to distinguish between gcc
2182 and Renesas calling convention. It also adds the new CLI commands
2183 `set/show sh calling-convention'.
2185 * GDB can now read compressed debug sections, as produced by GNU gold
2186 with the --compress-debug-sections=zlib flag.
2188 * 64-bit core files are now supported on AIX.
2190 * Thread switching is now supported on Tru64.
2192 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2193 which will be allocated using malloc later in program execution.
2195 * The qXfer:libraries:read remote procotol packet now allows passing a
2196 list of section offsets.
2198 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2199 conditions handling signals delivered during attach or thread creation
2200 have also been fixed.
2202 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2203 From the user's standpoint, all unqualified instances of True and False
2204 are treated as the standard definitions, regardless of context.
2206 * GDB now parses C++ symbol and type names more flexibly. For
2209 template<typename T> class C { };
2212 GDB will now correctly handle all of:
2214 ptype C<char const *>
2215 ptype C<char const*>
2216 ptype C<const char *>
2217 ptype C<const char*>
2219 * New features in the GDB remote stub, gdbserver
2221 - The "--wrapper" command-line argument tells gdbserver to use a
2222 wrapper program to launch programs for debugging.
2224 - On PowerPC and S/390 targets, it is now possible to use a single
2225 gdbserver executable to debug both 32-bit and 64-bit programs.
2226 (This requires gdbserver itself to be built as a 64-bit executable.)
2228 - gdbserver uses the new noack protocol mode for TCP connections to
2229 reduce communications latency, if also supported and enabled in GDB.
2231 - Support for the sparc64-linux-gnu target is now included in
2234 - The amd64-linux build of gdbserver now supports debugging both
2235 32-bit and 64-bit programs.
2237 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2238 now support hardware watchpoints, and will use them automatically
2243 GDB now has support for scripting using Python. Whether this is
2244 available is determined at configure time.
2246 New GDB commands can now be written in Python.
2248 * Ada tasking support
2250 Ada tasks can now be inspected in GDB. The following commands have
2254 Print the list of Ada tasks.
2256 Print detailed information about task number N.
2258 Print the task number of the current task.
2260 Switch the context of debugging to task number N.
2262 * Support for user-defined prefixed commands. The "define" command can
2263 add new commands to existing prefixes, e.g. "target".
2265 * Multi-inferior, multi-process debugging.
2267 GDB now has generalized support for multi-inferior debugging. See
2268 "Debugging Multiple Inferiors" in the manual for more information.
2269 Although availability still depends on target support, the command
2270 set is more uniform now. The GNU/Linux specific multi-forks support
2271 has been migrated to this new framework. This implied some user
2272 visible changes; see "New commands" and also "Removed commands"
2275 * Target descriptions can now describe the target OS ABI. See the
2276 "Target Description Format" section in the user manual for more
2279 * Target descriptions can now describe "compatible" architectures
2280 to indicate that the target can execute applications for a different
2281 architecture in addition to those for the main target architecture.
2282 See the "Target Description Format" section in the user manual for
2285 * Multi-architecture debugging.
2287 GDB now includes general supports for debugging applications on
2288 hybrid systems that use more than one single processor architecture
2289 at the same time. Each such hybrid architecture still requires
2290 specific support to be added. The only hybrid architecture supported
2291 in this version of GDB is the Cell Broadband Engine.
2293 * GDB now supports integrated debugging of Cell/B.E. applications that
2294 use both the PPU and SPU architectures. To enable support for hybrid
2295 Cell/B.E. debugging, you need to configure GDB to support both the
2296 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2297 --enable-targets configure option.
2299 * Non-stop mode debugging.
2301 For some targets, GDB now supports an optional mode of operation in
2302 which you can examine stopped threads while other threads continue
2303 to execute freely. This is referred to as non-stop mode, with the
2304 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2305 section in the user manual for more information.
2307 To be able to support remote non-stop debugging, a remote stub needs
2308 to implement the non-stop mode remote protocol extensions, as
2309 described in the "Remote Non-Stop" section of the user manual. The
2310 GDB remote stub, gdbserver, has been adjusted to support these
2311 extensions on linux targets.
2313 * New commands (for set/show, see "New options" below)
2315 catch syscall [NAME(S) | NUMBER(S)]
2316 Catch system calls. Arguments, which should be names of system
2317 calls or their numbers, mean catch only those syscalls. Without
2318 arguments, every syscall will be caught. When the inferior issues
2319 any of the specified syscalls, GDB will stop and announce the system
2320 call, both when it is called and when its call returns. This
2321 feature is currently available with a native GDB running on the
2322 Linux Kernel, under the following architectures: x86, x86_64,
2323 PowerPC and PowerPC64.
2325 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2327 Search memory for a sequence of bytes.
2329 maint set python print-stack
2330 maint show python print-stack
2331 Show a stack trace when an error is encountered in a Python script.
2334 Invoke CODE by passing it to the Python interpreter.
2339 These allow macros to be defined, undefined, and listed
2343 Show operating system information about processes.
2346 List the inferiors currently under GDB's control.
2349 Switch focus to inferior number NUM.
2352 Detach from inferior number NUM.
2355 Kill inferior number NUM.
2359 set spu stop-on-load
2360 show spu stop-on-load
2361 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2363 set spu auto-flush-cache
2364 show spu auto-flush-cache
2365 Control whether to automatically flush the software-managed cache
2366 during Cell/B.E. debugging.
2368 set sh calling-convention
2369 show sh calling-convention
2370 Control the calling convention used when calling SH target functions.
2373 show debug timestamp
2374 Control display of timestamps with GDB debugging output.
2376 set disassemble-next-line
2377 show disassemble-next-line
2378 Control display of disassembled source lines or instructions when
2381 set remote noack-packet
2382 show remote noack-packet
2383 Set/show the use of remote protocol QStartNoAckMode packet. See above
2384 under "New remote packets."
2386 set remote query-attached-packet
2387 show remote query-attached-packet
2388 Control use of remote protocol `qAttached' (query-attached) packet.
2390 set remote read-siginfo-object
2391 show remote read-siginfo-object
2392 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2395 set remote write-siginfo-object
2396 show remote write-siginfo-object
2397 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2400 set remote reverse-continue
2401 show remote reverse-continue
2402 Control use of remote protocol 'bc' (reverse-continue) packet.
2404 set remote reverse-step
2405 show remote reverse-step
2406 Control use of remote protocol 'bs' (reverse-step) packet.
2408 set displaced-stepping
2409 show displaced-stepping
2410 Control displaced stepping mode. Displaced stepping is a way to
2411 single-step over breakpoints without removing them from the debuggee.
2412 Also known as "out-of-line single-stepping".
2415 show debug displaced
2416 Control display of debugging info for displaced stepping.
2418 maint set internal-error
2419 maint show internal-error
2420 Control what GDB does when an internal error is detected.
2422 maint set internal-warning
2423 maint show internal-warning
2424 Control what GDB does when an internal warning is detected.
2429 Use a wrapper program to launch programs for debugging.
2431 set multiple-symbols (all|ask|cancel)
2432 show multiple-symbols
2433 The value of this variable can be changed to adjust the debugger behavior
2434 when an expression or a breakpoint location contains an ambiguous symbol
2435 name (an overloaded function name, for instance).
2437 set breakpoint always-inserted
2438 show breakpoint always-inserted
2439 Keep breakpoints always inserted in the target, as opposed to inserting
2440 them when resuming the target, and removing them when the target stops.
2441 This option can improve debugger performance on slow remote targets.
2443 set arm fallback-mode (arm|thumb|auto)
2444 show arm fallback-mode
2445 set arm force-mode (arm|thumb|auto)
2447 These commands control how ARM GDB determines whether instructions
2448 are ARM or Thumb. The default for both settings is auto, which uses
2449 the current CPSR value for instructions without symbols; previous
2450 versions of GDB behaved as if "set arm fallback-mode arm".
2452 set disable-randomization
2453 show disable-randomization
2454 Standalone programs run with the virtual address space randomization enabled
2455 by default on some platforms. This option keeps the addresses stable across
2456 multiple debugging sessions.
2460 Control whether other threads are stopped or not when some thread hits
2465 Requests that asynchronous execution is enabled in the target, if available.
2466 In this case, it's possible to resume target in the background, and interact
2467 with GDB while the target is running. "show target-async" displays the
2468 current state of asynchronous execution of the target.
2470 set target-wide-charset
2471 show target-wide-charset
2472 The target-wide-charset is the name of the character set that GDB
2473 uses when printing characters whose type is wchar_t.
2475 set tcp auto-retry (on|off)
2477 set tcp connect-timeout
2478 show tcp connect-timeout
2479 These commands allow GDB to retry failed TCP connections to a remote stub
2480 with a specified timeout period; this is useful if the stub is launched
2481 in parallel with GDB but may not be ready to accept connections immediately.
2483 set libthread-db-search-path
2484 show libthread-db-search-path
2485 Control list of directories which GDB will search for appropriate
2488 set schedule-multiple (on|off)
2489 show schedule-multiple
2490 Allow GDB to resume all threads of all processes or only threads of
2491 the current process.
2495 Use more aggressive caching for accesses to the stack. This improves
2496 performance of remote debugging (particularly backtraces) without
2497 affecting correctness.
2499 set interactive-mode (on|off|auto)
2500 show interactive-mode
2501 Control whether GDB runs in interactive mode (on) or not (off).
2502 When in interactive mode, GDB waits for the user to answer all
2503 queries. Otherwise, GDB does not wait and assumes the default
2504 answer. When set to auto (the default), GDB determines which
2505 mode to use based on the stdin settings.
2510 For program forks, this is replaced by the new more generic `info
2511 inferiors' command. To list checkpoints, you can still use the
2512 `info checkpoints' command, which was an alias for the `info forks'
2516 Replaced by the new `inferior' command. To switch between
2517 checkpoints, you can still use the `restart' command, which was an
2518 alias for the `fork' command.
2521 This is removed, since some targets don't have a notion of
2522 processes. To switch between processes, you can still use the
2523 `inferior' command using GDB's own inferior number.
2526 For program forks, this is replaced by the new more generic `kill
2527 inferior' command. To delete a checkpoint, you can still use the
2528 `delete checkpoint' command, which was an alias for the `delete
2532 For program forks, this is replaced by the new more generic `detach
2533 inferior' command. To detach a checkpoint, you can still use the
2534 `detach checkpoint' command, which was an alias for the `detach
2537 * New native configurations
2539 x86/x86_64 Darwin i[34567]86-*-darwin*
2541 x86_64 MinGW x86_64-*-mingw*
2545 Lattice Mico32 lm32-*
2546 x86 DICOS i[34567]86-*-dicos*
2547 x86_64 DICOS x86_64-*-dicos*
2550 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2551 (mingw32ce) debugging.
2557 These commands were actually not implemented on any target.
2559 *** Changes in GDB 6.8
2561 * New native configurations
2563 NetBSD/hppa hppa*-*netbsd*
2564 Xtensa GNU/Linux xtensa*-*-linux*
2568 NetBSD/hppa hppa*-*-netbsd*
2569 Xtensa GNU/Lunux xtensa*-*-linux*
2571 * Change in command line behavior -- corefiles vs. process ids.
2573 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2574 attaching to process NUMBER fails, GDB no longer attempts to open a
2575 core file named NUMBER. Attaching to a program using the -c option
2576 is no longer supported. Instead, use the '-p' or '--pid' options.
2578 * GDB can now be built as a native debugger for debugging Windows x86
2579 (mingw32) Portable Executable (PE) programs.
2581 * Pending breakpoints no longer change their number when their address
2584 * GDB now supports breakpoints with multiple locations,
2585 including breakpoints on C++ constructors, inside C++ templates,
2586 and in inlined functions.
2588 * GDB's ability to debug optimized code has been improved. GDB more
2589 accurately identifies function bodies and lexical blocks that occupy
2590 more than one contiguous range of addresses.
2592 * Target descriptions can now describe registers for PowerPC.
2594 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2595 registers on PowerPC targets.
2597 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2598 targets even when the libthread_db library is not available.
2600 * The GDB remote stub, gdbserver, now supports the new file transfer
2601 commands (remote put, remote get, and remote delete).
2603 * The GDB remote stub, gdbserver, now supports run and attach in
2604 extended-remote mode.
2606 * hppa*64*-*-hpux11* target broken
2607 The debugger is unable to start a program and fails with the following
2608 error: "Error trying to get information about dynamic linker".
2609 The gdb-6.7 release is also affected.
2611 * GDB now supports the --enable-targets= configure option to allow
2612 building a single GDB executable that supports multiple remote
2613 target architectures.
2615 * GDB now supports debugging C and C++ programs which use the
2616 Decimal Floating Point extension. In addition, the PowerPC target
2617 now has a set of pseudo-registers to inspect decimal float values
2618 stored in two consecutive float registers.
2620 * The -break-insert MI command can optionally create pending
2623 * Improved support for debugging Ada
2624 Many improvements to the Ada language support have been made. These
2626 - Better support for Ada2005 interface types
2627 - Improved handling of arrays and slices in general
2628 - Better support for Taft-amendment types
2629 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2631 - Improved command completion in Ada
2634 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2639 set print frame-arguments (all|scalars|none)
2640 show print frame-arguments
2641 The value of this variable can be changed to control which argument
2642 values should be printed by the debugger when displaying a frame.
2647 Transfer files to and from a remote target, and delete remote files.
2654 Transfer files to and from a remote target, and delete remote files.
2656 * New remote packets
2663 Open, close, read, write, and delete files on the remote system.
2666 Attach to an existing process on the remote system, in extended-remote
2670 Run a new process on the remote system, in extended-remote mode.
2672 *** Changes in GDB 6.7
2674 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2675 bfd, libiberty and opcodes, as revealed by static analysis donated by
2676 Coverity, Inc. (http://scan.coverity.com).
2678 * When looking up multiply-defined global symbols, GDB will now prefer the
2679 symbol definition in the current shared library if it was built using the
2680 -Bsymbolic linker option.
2682 * When the Text User Interface (TUI) is not configured, GDB will now
2683 recognize the -tui command-line option and print a message that the TUI
2686 * The GDB remote stub, gdbserver, now has lower overhead for high
2687 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2689 * GDB for MIPS targets now autodetects whether a remote target provides
2690 32-bit or 64-bit register values.
2692 * Support for C++ member pointers has been improved.
2694 * GDB now understands XML target descriptions, which specify the
2695 target's overall architecture. GDB can read a description from
2696 a local file or over the remote serial protocol.
2698 * Vectors of single-byte data use a new integer type which is not
2699 automatically displayed as character or string data.
2701 * The /s format now works with the print command. It displays
2702 arrays of single-byte integers and pointers to single-byte integers
2705 * Target descriptions can now describe target-specific registers,
2706 for architectures which have implemented the support (currently
2707 only ARM, M68K, and MIPS).
2709 * GDB and the GDB remote stub, gdbserver, now support the XScale
2712 * The GDB remote stub, gdbserver, has been updated to support
2713 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2714 has been rewritten to use the standard GDB remote protocol.
2716 * GDB can now step into C++ functions which are called through thunks.
2718 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2720 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2721 layout. It also supports a TextSeg= and DataSeg= response when only
2722 segment base addresses (rather than offsets) are available.
2724 * The /i format now outputs any trailing branch delay slot instructions
2725 immediately following the last instruction within the count specified.
2727 * The GDB remote protocol "T" stop reply packet now supports a
2728 "library" response. Combined with the new "qXfer:libraries:read"
2729 packet, this response allows GDB to debug shared libraries on targets
2730 where the operating system manages the list of loaded libraries (e.g.
2731 Windows and SymbianOS).
2733 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2734 (DLLs) on Windows and Windows CE targets.
2736 * GDB now supports a faster verification that a .debug file matches its binary
2737 according to its build-id signature, if the signature is present.
2743 Enable or disable hardware flow control (RTS/CTS) on the serial port
2744 when debugging using remote targets.
2746 set mem inaccessible-by-default
2747 show mem inaccessible-by-default
2748 If the target supplies a memory map, for instance via the remote
2749 protocol's "qXfer:memory-map:read" packet, setting this variable
2750 prevents GDB from accessing memory outside the memory map. This
2751 is useful for targets with memory mapped registers or which react
2752 badly to accesses of unmapped address space.
2754 set breakpoint auto-hw
2755 show breakpoint auto-hw
2756 If the target supplies a memory map, for instance via the remote
2757 protocol's "qXfer:memory-map:read" packet, setting this variable
2758 lets GDB use hardware breakpoints automatically for memory regions
2759 where it can not use software breakpoints. This covers both the
2760 "break" command and internal breakpoints used for other commands
2761 including "next" and "finish".
2764 catch exception unhandled
2765 Stop the program execution when Ada exceptions are raised.
2768 Stop the program execution when an Ada assertion failed.
2772 Set an alternate system root for target files. This is a more
2773 general version of "set solib-absolute-prefix", which is now
2774 an alias to "set sysroot".
2777 Provide extended SPU facility status information. This set of
2778 commands is available only when debugging the Cell/B.E. SPU
2781 * New native configurations
2783 OpenBSD/sh sh*-*openbsd*
2786 unset tdesc filename
2788 Use the specified local file as an XML target description, and do
2789 not query the target for its built-in description.
2793 OpenBSD/sh sh*-*-openbsd*
2794 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2795 Toshiba Media Processor mep-elf
2797 * New remote packets
2800 Ignore the specified signals; pass them directly to the debugged program
2801 without stopping other threads or reporting them to GDB.
2803 qXfer:features:read:
2804 Read an XML target description from the target, which describes its
2809 Read or write contents of an spufs file on the target system. These
2810 packets are available only on the Cell/B.E. SPU architecture.
2812 qXfer:libraries:read:
2813 Report the loaded shared libraries. Combined with new "T" packet
2814 response, this packet allows GDB to debug shared libraries on
2815 targets where the operating system manages the list of loaded
2816 libraries (e.g. Windows and SymbianOS).
2820 Support for these obsolete configurations has been removed.
2828 i[34567]86-*-lynxos*
2829 i[34567]86-*-netware*
2830 i[34567]86-*-sco3.2v5*
2831 i[34567]86-*-sco3.2v4*
2833 i[34567]86-*-sysv4.2*
2836 i[34567]86-*-unixware2*
2837 i[34567]86-*-unixware*
2846 * Other removed features
2853 Various m68k-only ROM monitors.
2860 Various Renesas ROM monitors and debugging interfaces for SH and
2865 Support for a Macraigor serial interface to on-chip debugging.
2866 GDB does not directly support the newer parallel or USB
2871 A debug information format. The predecessor to DWARF 2 and
2872 DWARF 3, which are still supported.
2874 Support for the HP aCC compiler on HP-UX/PA-RISC
2876 SOM-encapsulated symbolic debugging information, automatic
2877 invocation of pxdb, and the aCC custom C++ ABI. This does not
2878 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2879 with aCC can still be debugged on an assembly level.
2881 MIPS ".pdr" sections
2883 A MIPS-specific format used to describe stack frame layout
2884 in debugging information.
2888 GDB could work with an older version of Guile to debug
2889 the interpreter and Scheme programs running in it.
2891 set mips stack-arg-size
2892 set mips saved-gpreg-size
2894 Use "set mips abi" to control parameter passing for MIPS.
2896 *** Changes in GDB 6.6
2901 Cell Broadband Engine SPU spu-elf
2903 * GDB can now be configured as a cross-debugger targeting native Windows
2904 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2905 running on a Windows system over TCP/IP to debug Windows programs.
2907 * The GDB remote stub, gdbserver, has been updated to support Windows and
2908 Cygwin debugging. Both single-threaded and multi-threaded programs are
2911 * The "set trust-readonly-sections" command works again. This command was
2912 broken in GDB 6.3, 6.4, and 6.5.
2914 * The "load" command now supports writing to flash memory, if the remote
2915 stub provides the required support.
2917 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2918 longer requires symbolic debug information (e.g. DWARF-2).
2923 unset substitute-path
2924 show substitute-path
2925 Manage a list of substitution rules that GDB uses to rewrite the name
2926 of the directories where the sources are located. This can be useful
2927 for instance when the sources were moved to a different location
2928 between compilation and debugging.
2932 Print each CLI command as it is executed. Each command is prefixed with
2933 a number of `+' symbols representing the nesting depth.
2934 The source command now has a `-v' option to enable the same feature.
2938 The ARM Demon monitor support (RDP protocol, "target rdp").
2940 Kernel Object Display, an embedded debugging feature which only worked with
2941 an obsolete version of Cisco IOS.
2943 The 'set download-write-size' and 'show download-write-size' commands.
2945 * New remote packets
2948 Tell a stub about GDB client features, and request remote target features.
2949 The first feature implemented is PacketSize, which allows the target to
2950 specify the size of packets it can handle - to minimize the number of
2951 packets required and improve performance when connected to a remote
2955 Fetch an OS auxilliary vector from the remote stub. This packet is a
2956 more efficient replacement for qPart:auxv:read.
2958 qXfer:memory-map:read:
2959 Fetch a memory map from the remote stub, including information about
2960 RAM, ROM, and flash memory devices.
2965 Erase and program a flash memory device.
2967 * Removed remote packets
2970 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2971 used it, and only gdbserver implemented it.
2973 *** Changes in GDB 6.5
2977 Renesas M32C/M16C m32c-elf
2979 Morpho Technologies ms1 ms1-elf
2983 init-if-undefined Initialize a convenience variable, but
2984 only if it doesn't already have a value.
2986 The following commands are presently only implemented for native GNU/Linux:
2988 checkpoint Save a snapshot of the program state.
2990 restart <n> Return the program state to a
2991 previously saved state.
2993 info checkpoints List currently saved checkpoints.
2995 delete-checkpoint <n> Delete a previously saved checkpoint.
2997 set|show detach-on-fork Tell gdb whether to detach from a newly
2998 forked process, or to keep debugging it.
3000 info forks List forks of the user program that
3001 are available to be debugged.
3003 fork <n> Switch to debugging one of several
3004 forks of the user program that are
3005 available to be debugged.
3007 delete-fork <n> Delete a fork from the list of forks
3008 that are available to be debugged (and
3009 kill the forked process).
3011 detach-fork <n> Delete a fork from the list of forks
3012 that are available to be debugged (and
3013 allow the process to continue).
3017 Morpho Technologies ms2 ms1-elf
3019 * Improved Windows host support
3021 GDB now builds as a cross debugger hosted on i686-mingw32, including
3022 native console support, and remote communications using either
3023 network sockets or serial ports.
3025 * Improved Modula-2 language support
3027 GDB can now print most types in the Modula-2 syntax. This includes:
3028 basic types, set types, record types, enumerated types, range types,
3029 pointer types and ARRAY types. Procedure var parameters are correctly
3030 printed and hexadecimal addresses and character constants are also
3031 written in the Modula-2 syntax. Best results can be obtained by using
3032 GNU Modula-2 together with the -gdwarf-2 command line option.
3036 The ARM rdi-share module.
3038 The Netware NLM debug server.
3040 *** Changes in GDB 6.4
3042 * New native configurations
3044 OpenBSD/arm arm*-*-openbsd*
3045 OpenBSD/mips64 mips64-*-openbsd*
3049 Morpho Technologies ms1 ms1-elf
3051 * New command line options
3053 --batch-silent As for --batch, but totally silent.
3054 --return-child-result The debugger will exist with the same value
3055 the child (debugged) program exited with.
3056 --eval-command COMMAND, -ex COMMAND
3057 Execute a single GDB CLI command. This may be
3058 specified multiple times and in conjunction
3059 with the --command (-x) option.
3061 * Deprecated commands removed
3063 The following commands, that were deprecated in 2000, have been
3067 set|show arm disassembly-flavor set|show arm disassembler
3068 othernames set arm disassembler
3069 set|show remotedebug set|show debug remote
3070 set|show archdebug set|show debug arch
3071 set|show eventdebug set|show debug event
3074 * New BSD user-level threads support
3076 It is now possible to debug programs using the user-level threads
3077 library on OpenBSD and FreeBSD. Currently supported (target)
3080 FreeBSD/amd64 x86_64-*-freebsd*
3081 FreeBSD/i386 i386-*-freebsd*
3082 OpenBSD/i386 i386-*-openbsd*
3084 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3085 are not yet supported.
3087 * New support for Matsushita MN10300 w/sim added
3088 (Work in progress). mn10300-elf.
3090 * REMOVED configurations and files
3092 VxWorks and the XDR protocol *-*-vxworks
3093 Motorola MCORE mcore-*-*
3094 National Semiconductor NS32000 ns32k-*-*
3096 * New "set print array-indexes" command
3098 After turning this setting "on", GDB prints the index of each element
3099 when displaying arrays. The default is "off" to preserve the previous
3102 * VAX floating point support
3104 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3106 * User-defined command support
3108 In addition to using $arg0..$arg9 for argument passing, it is now possible
3109 to use $argc to determine now many arguments have been passed. See the
3110 section on user-defined commands in the user manual for more information.
3112 *** Changes in GDB 6.3:
3114 * New command line option
3116 GDB now accepts -l followed by a number to set the timeout for remote
3119 * GDB works with GCC -feliminate-dwarf2-dups
3121 GDB now supports a more compact representation of DWARF-2 debug
3122 information using DW_FORM_ref_addr references. These are produced
3123 by GCC with the option -feliminate-dwarf2-dups and also by some
3124 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3125 to use -feliminate-dwarf2-dups.
3127 * Internationalization
3129 When supported by the host system, GDB will be built with
3130 internationalization (libintl). The task of marking up the sources is
3131 continued, we're looking forward to our first translation.
3135 Initial support for debugging programs compiled with the GNAT
3136 implementation of the Ada programming language has been integrated
3137 into GDB. In this release, support is limited to expression evaluation.
3139 * New native configurations
3141 GNU/Linux/m32r m32r-*-linux-gnu
3145 GDB's remote protocol now includes support for the 'p' packet. This
3146 packet is used to fetch individual registers from a remote inferior.
3148 * END-OF-LIFE registers[] compatibility module
3150 GDB's internal register infrastructure has been completely rewritten.
3151 The new infrastructure making possible the implementation of key new
3152 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3155 GDB 6.3 will be the last release to include the the registers[]
3156 compatibility module that allowed out-of-date configurations to
3157 continue to work. This change directly impacts the following
3167 powerpc bdm protocol
3169 Unless there is activity to revive these configurations, they will be
3170 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3172 * OBSOLETE configurations and files
3174 Configurations that have been declared obsolete in this release have
3175 been commented out. Unless there is activity to revive these
3176 configurations, the next release of GDB will have their sources
3177 permanently REMOVED.
3186 *** Changes in GDB 6.2.1:
3188 * MIPS `break main; run' gave an heuristic-fence-post warning
3190 When attempting to run even a simple program, a warning about
3191 heuristic-fence-post being hit would be reported. This problem has
3194 * MIPS IRIX 'long double' crashed GDB
3196 When examining a long double variable, GDB would get a segmentation
3197 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3198 IRIX long double values).
3202 A bug in the VAX stack code was causing problems with the "next"
3203 command. This problem has been fixed.
3205 *** Changes in GDB 6.2:
3207 * Fix for ``many threads''
3209 On GNU/Linux systems that use the NPTL threads library, a program
3210 rapidly creating and deleting threads would confuse GDB leading to the
3213 ptrace: No such process.
3214 thread_db_get_info: cannot get thread info: generic error
3216 This problem has been fixed.
3218 * "-async" and "-noasync" options removed.
3220 Support for the broken "-noasync" option has been removed (it caused
3223 * New ``start'' command.
3225 This command runs the program until the begining of the main procedure.
3227 * New BSD Kernel Data Access Library (libkvm) interface
3229 Using ``target kvm'' it is now possible to debug kernel core dumps and
3230 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3231 platforms. Currently supported (native-only) configurations are:
3233 FreeBSD/amd64 x86_64-*-freebsd*
3234 FreeBSD/i386 i?86-*-freebsd*
3235 NetBSD/i386 i?86-*-netbsd*
3236 NetBSD/m68k m68*-*-netbsd*
3237 NetBSD/sparc sparc-*-netbsd*
3238 OpenBSD/amd64 x86_64-*-openbsd*
3239 OpenBSD/i386 i?86-*-openbsd*
3240 OpenBSD/m68k m68*-openbsd*
3241 OpenBSD/sparc sparc-*-openbsd*
3243 * Signal trampoline code overhauled
3245 Many generic problems with GDB's signal handling code have been fixed.
3246 These include: backtraces through non-contiguous stacks; recognition
3247 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3248 call; backtrace through a signal trampoline; step into and out of
3249 signal handlers; and single-stepping in the signal trampoline.
3251 Please note that kernel bugs are a limiting factor here. These
3252 features have been shown to work on an s390 GNU/Linux system that
3253 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3255 * Cygwin support for DWARF 2 added.
3257 * New native configurations
3259 GNU/Linux/hppa hppa*-*-linux*
3260 OpenBSD/hppa hppa*-*-openbsd*
3261 OpenBSD/m68k m68*-*-openbsd*
3262 OpenBSD/m88k m88*-*-openbsd*
3263 OpenBSD/powerpc powerpc-*-openbsd*
3264 NetBSD/vax vax-*-netbsd*
3265 OpenBSD/vax vax-*-openbsd*
3267 * END-OF-LIFE frame compatibility module
3269 GDB's internal frame infrastructure has been completely rewritten.
3270 The new infrastructure making it possible to support key new features
3271 including DWARF 2 Call Frame Information. To aid in the task of
3272 migrating old configurations to this new infrastructure, a
3273 compatibility module, that allowed old configurations to continue to
3274 work, was also included.
3276 GDB 6.2 will be the last release to include this frame compatibility
3277 module. This change directly impacts the following configurations:
3287 Unless there is activity to revive these configurations, they will be
3288 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3290 * REMOVED configurations and files
3292 Sun 3, running SunOS 3 m68*-*-sunos3*
3293 Sun 3, running SunOS 4 m68*-*-sunos4*
3294 Sun 2, running SunOS 3 m68000-*-sunos3*
3295 Sun 2, running SunOS 4 m68000-*-sunos4*
3296 Motorola 680x0 running LynxOS m68*-*-lynxos*
3297 AT&T 3b1/Unix pc m68*-att-*
3298 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3299 decstation mips-dec-* mips-little-*
3300 riscos mips-*-riscos* mips-*-sysv*
3301 sonymips mips-sony-*
3302 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3304 *** Changes in GDB 6.1.1:
3306 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3308 The TUI (Text-mode User Interface) is now built as part of a default
3309 GDB configuration. It is enabled by either selecting the TUI with the
3310 command line option "-i=tui" or by running the separate "gdbtui"
3311 program. For more information on the TUI, see the manual "Debugging
3314 * Pending breakpoint support (also included in GDB 6.1)
3316 Support has been added to allow you to specify breakpoints in shared
3317 libraries that have not yet been loaded. If a breakpoint location
3318 cannot be found, and the "breakpoint pending" option is set to auto,
3319 GDB queries you if you wish to make the breakpoint pending on a future
3320 shared-library load. If and when GDB resolves the breakpoint symbol,
3321 the pending breakpoint is removed as one or more regular breakpoints
3324 Pending breakpoints are very useful for GCJ Java debugging.
3326 * Fixed ISO-C build problems
3328 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3329 non ISO-C code that stopped them being built using a more strict ISO-C
3330 compiler (e.g., IBM's C compiler).
3332 * Fixed build problem on IRIX 5
3334 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3335 wasn't able to compile compile on an IRIX 5 system.
3337 * Added execute permission to gdb/gdbserver/configure
3339 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3340 permission. This bug would cause configure to fail on a number of
3341 systems (Solaris, IRIX). Ref: server/519.
3343 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3345 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3346 has been updated to use constant array sizes.
3348 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3350 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3351 its generated DWARF Call Frame Info. This encoding was causing GDB to
3352 panic, that panic has been fixed. Ref: gdb/1628.
3354 * Fixed a problem when examining parameters in shared library code.
3356 When examining parameters in optimized shared library code generated
3357 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3358 not available''. GDB now correctly displays the variable's value.
3360 *** Changes in GDB 6.1:
3362 * Removed --with-mmalloc
3364 Support for the mmalloc memory manager has been removed, as it
3365 conflicted with the internal gdb byte cache.
3367 * Changes in AMD64 configurations
3369 The AMD64 target now includes the %cs and %ss registers. As a result
3370 the AMD64 remote protocol has changed; this affects the floating-point
3371 and SSE registers. If you rely on those registers for your debugging,
3372 you should upgrade gdbserver on the remote side.
3374 * Revised SPARC target
3376 The SPARC target has been completely revised, incorporating the
3377 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3378 support for LynxOS and SunOS 4 has been dropped. Calling functions
3379 from within GDB on operating systems with a non-executable stack
3380 (Solaris, OpenBSD) now works.
3384 GDB has a new C++ demangler which does a better job on the mangled
3385 names generated by current versions of g++. It also runs faster, so
3386 with this and other changes gdb should now start faster on large C++
3389 * DWARF 2 Location Expressions
3391 GDB support for location expressions has been extended to support function
3392 arguments and frame bases. Older versions of GDB could crash when they
3395 * C++ nested types and namespaces
3397 GDB's support for nested types and namespaces in C++ has been
3398 improved, especially if you use the DWARF 2 debugging format. (This
3399 is the default for recent versions of GCC on most platforms.)
3400 Specifically, if you have a class "Inner" defined within a class or
3401 namespace "Outer", then GDB realizes that the class's name is
3402 "Outer::Inner", not simply "Inner". This should greatly reduce the
3403 frequency of complaints about not finding RTTI symbols. In addition,
3404 if you are stopped at inside of a function defined within a namespace,
3405 GDB modifies its name lookup accordingly.
3407 * New native configurations
3409 NetBSD/amd64 x86_64-*-netbsd*
3410 OpenBSD/amd64 x86_64-*-openbsd*
3411 OpenBSD/alpha alpha*-*-openbsd*
3412 OpenBSD/sparc sparc-*-openbsd*
3413 OpenBSD/sparc64 sparc64-*-openbsd*
3415 * New debugging protocols
3417 M32R with SDI protocol m32r-*-elf*
3419 * "set prompt-escape-char" command deleted.
3421 The command "set prompt-escape-char" has been deleted. This command,
3422 and its very obscure effet on GDB's prompt, was never documented,
3423 tested, nor mentioned in the NEWS file.
3425 * OBSOLETE configurations and files
3427 Configurations that have been declared obsolete in this release have
3428 been commented out. Unless there is activity to revive these
3429 configurations, the next release of GDB will have their sources
3430 permanently REMOVED.
3432 Sun 3, running SunOS 3 m68*-*-sunos3*
3433 Sun 3, running SunOS 4 m68*-*-sunos4*
3434 Sun 2, running SunOS 3 m68000-*-sunos3*
3435 Sun 2, running SunOS 4 m68000-*-sunos4*
3436 Motorola 680x0 running LynxOS m68*-*-lynxos*
3437 AT&T 3b1/Unix pc m68*-att-*
3438 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3439 decstation mips-dec-* mips-little-*
3440 riscos mips-*-riscos* mips-*-sysv*
3441 sonymips mips-sony-*
3442 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3444 * REMOVED configurations and files
3446 SGI Irix-4.x mips-sgi-irix4 or iris4
3447 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3448 Z8000 simulator z8k-zilog-none or z8ksim
3449 Matsushita MN10200 w/simulator mn10200-*-*
3450 H8/500 simulator h8500-hitachi-hms or h8500hms
3451 HP/PA running BSD hppa*-*-bsd*
3452 HP/PA running OSF/1 hppa*-*-osf*
3453 HP/PA Pro target hppa*-*-pro*
3454 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3455 386BSD i[3456]86-*-bsd*
3456 Sequent family i[3456]86-sequent-sysv4*
3457 i[3456]86-sequent-sysv*
3458 i[3456]86-sequent-bsd*
3459 SPARC running LynxOS sparc-*-lynxos*
3460 SPARC running SunOS 4 sparc-*-sunos4*
3461 Tsqware Sparclet sparclet-*-*
3462 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3464 *** Changes in GDB 6.0:
3468 Support for debugging the Objective-C programming language has been
3469 integrated into GDB.
3471 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3473 DWARF 2's Call Frame Information makes available compiler generated
3474 information that more exactly describes the program's run-time stack.
3475 By using this information, GDB is able to provide more robust stack
3478 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3479 have been updated to use a new backtrace mechanism which includes
3480 DWARF 2 CFI support.
3484 GDB's remote protocol has been extended to include support for hosted
3485 file I/O (where the remote target uses GDB's file system). See GDB's
3486 remote protocol documentation for details.
3488 * All targets using the new architecture framework.
3490 All of GDB's targets have been updated to use the new internal
3491 architecture framework. The way is now open for future GDB releases
3492 to include cross-architecture native debugging support (i386 on amd64,
3495 * GNU/Linux's Thread Local Storage (TLS)
3497 GDB now includes support for for the GNU/Linux implementation of
3498 per-thread variables.
3500 * GNU/Linux's Native POSIX Thread Library (NPTL)
3502 GDB's thread code has been updated to work with either the new
3503 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3505 * Separate debug info.
3507 GDB, in conjunction with BINUTILS, now supports a mechanism for
3508 automatically loading debug information from a separate file. Instead
3509 of shipping full debug and non-debug versions of system libraries,
3510 system integrators can now instead ship just the stripped libraries
3511 and optional debug files.
3513 * DWARF 2 Location Expressions
3515 DWARF 2 Location Expressions allow the compiler to more completely
3516 describe the location of variables (even in optimized code) to the
3519 GDB now includes preliminary support for location expressions (support
3520 for DW_OP_piece is still missing).
3524 A number of long standing bugs that caused GDB to die while starting a
3525 Java application have been fixed. GDB's Java support is now
3526 considered "useable".
3528 * GNU/Linux support for fork, vfork, and exec.
3530 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3531 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3534 * GDB supports logging output to a file
3536 There are two new commands, "set logging" and "show logging", which can be
3537 used to capture GDB's output to a file.
3539 * The meaning of "detach" has changed for gdbserver
3541 The "detach" command will now resume the application, as documented. To
3542 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3545 * d10v, m68hc11 `regs' command deprecated
3547 The `info registers' command has been updated so that it displays the
3548 registers using a format identical to the old `regs' command.
3552 A new command, "maint set profile on/off", has been added. This command can
3553 be used to enable or disable profiling while running GDB, to profile a
3554 session or a set of commands. In addition there is a new configure switch,
3555 "--enable-profiling", which will cause GDB to be compiled with profiling
3556 data, for more informative profiling results.
3558 * Default MI syntax changed to "mi2".
3560 The default MI (machine interface) syntax, enabled by the command line
3561 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3562 "mi1", can be enabled by specifying the option "-i=mi1".
3564 Support for the original "mi0" syntax (included in GDB 5.0) has been
3567 Fix for gdb/192: removed extraneous space when displaying frame level.
3568 Fix for gdb/672: update changelist is now output in mi list format.
3569 Fix for gdb/702: a -var-assign that updates the value now shows up
3570 in a subsequent -var-update.
3572 * New native configurations.
3574 FreeBSD/amd64 x86_64-*-freebsd*
3576 * Multi-arched targets.
3578 HP/PA HPUX11 hppa*-*-hpux*
3579 Renesas M32R/D w/simulator m32r-*-elf*
3581 * OBSOLETE configurations and files
3583 Configurations that have been declared obsolete in this release have
3584 been commented out. Unless there is activity to revive these
3585 configurations, the next release of GDB will have their sources
3586 permanently REMOVED.
3588 Z8000 simulator z8k-zilog-none or z8ksim
3589 Matsushita MN10200 w/simulator mn10200-*-*
3590 H8/500 simulator h8500-hitachi-hms or h8500hms
3591 HP/PA running BSD hppa*-*-bsd*
3592 HP/PA running OSF/1 hppa*-*-osf*
3593 HP/PA Pro target hppa*-*-pro*
3594 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3595 Sequent family i[3456]86-sequent-sysv4*
3596 i[3456]86-sequent-sysv*
3597 i[3456]86-sequent-bsd*
3598 Tsqware Sparclet sparclet-*-*
3599 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3601 * REMOVED configurations and files
3604 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3605 IBM AIX PS/2 i[3456]86-*-aix
3606 i386 running Mach 3.0 i[3456]86-*-mach3*
3607 i386 running Mach i[3456]86-*-mach*
3608 i386 running OSF/1 i[3456]86-*osf1mk*
3609 HP/Apollo 68k Family m68*-apollo*-sysv*,
3611 m68*-hp-bsd*, m68*-hp-hpux*
3612 Argonaut Risc Chip (ARC) arc-*-*
3613 Mitsubishi D30V d30v-*-*
3614 Fujitsu FR30 fr30-*-elf*
3615 OS/9000 i[34]86-*-os9k
3616 I960 with MON960 i960-*-coff
3618 * MIPS $fp behavior changed
3620 The convenience variable $fp, for the MIPS, now consistently returns
3621 the address of the current frame's base. Previously, depending on the
3622 context, $fp could refer to either $sp or the current frame's base
3623 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3624 The GNU Source-Level Debugger''.
3626 *** Changes in GDB 5.3:
3628 * GNU/Linux shared library multi-threaded performance improved.
3630 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3631 `/proc', in preference to `ptrace' for memory reads. This may result
3632 in an improvement in the start-up time of multi-threaded, shared
3633 library applications when run under GDB. One GDB user writes: ``loads
3634 shared libs like mad''.
3636 * ``gdbserver'' now supports multi-threaded applications on some targets
3638 Support for debugging multi-threaded applications which use
3639 the GNU/Linux LinuxThreads package has been added for
3640 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3641 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3643 * GDB now supports C/C++ preprocessor macros.
3645 GDB now expands preprocessor macro invocations in C/C++ expressions,
3646 and provides various commands for showing macro definitions and how
3649 The new command `macro expand EXPRESSION' expands any macro
3650 invocations in expression, and shows the result.
3652 The new command `show macro MACRO-NAME' shows the definition of the
3653 macro named MACRO-NAME, and where it was defined.
3655 Most compilers don't include information about macros in the debugging
3656 information by default. In GCC 3.1, for example, you need to compile
3657 your program with the options `-gdwarf-2 -g3'. If the macro
3658 information is present in the executable, GDB will read it.
3660 * Multi-arched targets.
3662 DEC Alpha (partial) alpha*-*-*
3663 DEC VAX (partial) vax-*-*
3665 National Semiconductor NS32000 (partial) ns32k-*-*
3666 Motorola 68000 (partial) m68k-*-*
3667 Motorola MCORE mcore-*-*
3671 Fujitsu FRV architecture added by Red Hat frv*-*-*
3674 * New native configurations
3676 Alpha NetBSD alpha*-*-netbsd*
3677 SH NetBSD sh*-*-netbsdelf*
3678 MIPS NetBSD mips*-*-netbsd*
3679 UltraSPARC NetBSD sparc64-*-netbsd*
3681 * OBSOLETE configurations and files
3683 Configurations that have been declared obsolete in this release have
3684 been commented out. Unless there is activity to revive these
3685 configurations, the next release of GDB will have their sources
3686 permanently REMOVED.
3688 Mitsubishi D30V d30v-*-*
3689 OS/9000 i[34]86-*-os9k
3690 IBM AIX PS/2 i[3456]86-*-aix
3691 Fujitsu FR30 fr30-*-elf*
3692 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3693 Argonaut Risc Chip (ARC) arc-*-*
3694 i386 running Mach 3.0 i[3456]86-*-mach3*
3695 i386 running Mach i[3456]86-*-mach*
3696 i386 running OSF/1 i[3456]86-*osf1mk*
3697 HP/Apollo 68k Family m68*-apollo*-sysv*,
3699 m68*-hp-bsd*, m68*-hp-hpux*
3700 I960 with MON960 i960-*-coff
3702 * OBSOLETE languages
3704 CHILL, a Pascal like language used by telecommunications companies.
3706 * REMOVED configurations and files
3708 AMD 29k family via UDI a29k-amd-udi, udi29k
3709 A29K VxWorks a29k-*-vxworks
3710 AMD 29000 embedded, using EBMON a29k-none-none
3711 AMD 29000 embedded with COFF a29k-none-coff
3712 AMD 29000 embedded with a.out a29k-none-aout
3714 testsuite/gdb.hp/gdb.threads-hp/ directory
3716 * New command "set max-user-call-depth <nnn>"
3718 This command allows the user to limit the call depth of user-defined
3719 commands. The default is 1024.
3721 * Changes in FreeBSD/i386 native debugging.
3723 Support for the "generate-core-file" has been added.
3725 * New commands "dump", "append", and "restore".
3727 These commands allow data to be copied from target memory
3728 to a bfd-format or binary file (dump and append), and back
3729 from a file into memory (restore).
3731 * Improved "next/step" support on multi-processor Alpha Tru64.
3733 The previous single-step mechanism could cause unpredictable problems,
3734 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3735 of a software single-step mechanism prevents this.
3737 *** Changes in GDB 5.2.1:
3745 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3746 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3747 Fix, by Joel Brobecker imported from mainline.
3749 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3750 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3751 Fix, by Fred Fish, imported from mainline.
3753 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3754 Surprisingly enough, it works now.
3755 By Michal Ludvig, imported from mainline.
3757 i386 hardware watchpoint support:
3758 avoid misses on second run for some targets.
3759 By Pierre Muller, imported from mainline.
3761 *** Changes in GDB 5.2:
3763 * New command "set trust-readonly-sections on[off]".
3765 This command is a hint that tells gdb that read-only sections
3766 really are read-only (ie. that their contents will not change).
3767 In this mode, gdb will go to the object file rather than the
3768 target to read memory from read-only sections (such as ".text").
3769 This can be a significant performance improvement on some
3770 (notably embedded) targets.
3772 * New command "generate-core-file" (or "gcore").
3774 This new gdb command allows the user to drop a core file of the child
3775 process state at any time. So far it's been implemented only for
3776 GNU/Linux and Solaris, but should be relatively easily ported to other
3777 hosts. Argument is core file name (defaults to core.<pid>).
3779 * New command line option
3781 GDB now accepts --pid or -p followed by a process id.
3783 * Change in command line behavior -- corefiles vs. process ids.
3785 There is a subtle behavior in the way in which GDB handles
3786 command line arguments. The first non-flag argument is always
3787 a program to debug, but the second non-flag argument may either
3788 be a corefile or a process id. Previously, GDB would attempt to
3789 open the second argument as a corefile, and if that failed, would
3790 issue a superfluous error message and then attempt to attach it as
3791 a process. Now, if the second argument begins with a non-digit,
3792 it will be treated as a corefile. If it begins with a digit,
3793 GDB will attempt to attach it as a process, and if no such process
3794 is found, will then attempt to open it as a corefile.
3796 * Changes in ARM configurations.
3798 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3799 configuration is fully multi-arch.
3801 * New native configurations
3803 ARM NetBSD arm*-*-netbsd*
3804 x86 OpenBSD i[3456]86-*-openbsd*
3805 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3806 Sparc64 running FreeBSD sparc64-*-freebsd*
3810 Sanyo XStormy16 xstormy16-elf
3812 * OBSOLETE configurations and files
3814 Configurations that have been declared obsolete in this release have
3815 been commented out. Unless there is activity to revive these
3816 configurations, the next release of GDB will have their sources
3817 permanently REMOVED.
3819 AMD 29k family via UDI a29k-amd-udi, udi29k
3820 A29K VxWorks a29k-*-vxworks
3821 AMD 29000 embedded, using EBMON a29k-none-none
3822 AMD 29000 embedded with COFF a29k-none-coff
3823 AMD 29000 embedded with a.out a29k-none-aout
3825 testsuite/gdb.hp/gdb.threads-hp/ directory
3827 * REMOVED configurations and files
3829 TI TMS320C80 tic80-*-*
3831 PowerPC Solaris powerpcle-*-solaris*
3832 PowerPC Windows NT powerpcle-*-cygwin32
3833 PowerPC Netware powerpc-*-netware*
3834 Harris/CXUX m88k m88*-harris-cxux*
3835 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3836 ns32k-utek-sysv* ns32k-utek-*
3837 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3838 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3839 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3840 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3841 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3843 * Changes to command line processing
3845 The new `--args' feature can be used to specify command-line arguments
3846 for the inferior from gdb's command line.
3848 * Changes to key bindings
3850 There is a new `operate-and-get-next' function bound to `C-o'.
3852 *** Changes in GDB 5.1.1
3854 Fix compile problem on DJGPP.
3856 Fix a problem with floating-point registers on the i386 being
3859 Fix to stop GDB crashing on .debug_str debug info.
3861 Numerous documentation fixes.
3863 Numerous testsuite fixes.
3865 *** Changes in GDB 5.1:
3867 * New native configurations
3869 Alpha FreeBSD alpha*-*-freebsd*
3870 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3871 MIPS GNU/Linux mips*-*-linux*
3872 MIPS SGI Irix 6.x mips*-sgi-irix6*
3873 ia64 AIX ia64-*-aix*
3874 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3878 Motorola 68HC11 and 68HC12 m68hc11-elf
3880 UltraSparc running GNU/Linux sparc64-*-linux*
3882 * OBSOLETE configurations and files
3884 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3885 Harris/CXUX m88k m88*-harris-cxux*
3886 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3887 ns32k-utek-sysv* ns32k-utek-*
3888 TI TMS320C80 tic80-*-*
3890 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3891 PowerPC Solaris powerpcle-*-solaris*
3892 PowerPC Windows NT powerpcle-*-cygwin32
3893 PowerPC Netware powerpc-*-netware*
3894 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3895 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3896 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3897 Apple Macintosh (MPW) host N/A
3899 stuff.c (Program to stuff files into a specially prepared space in kdb)
3900 kdb-start.c (Main loop for the standalone kernel debugger)
3902 Configurations that have been declared obsolete in this release have
3903 been commented out. Unless there is activity to revive these
3904 configurations, the next release of GDB will have their sources
3905 permanently REMOVED.
3907 * REMOVED configurations and files
3909 Altos 3068 m68*-altos-*
3910 Convex c1-*-*, c2-*-*
3912 ARM RISCix arm-*-* (as host)
3916 * GDB has been converted to ISO C.
3918 GDB's source code has been converted to ISO C. In particular, the
3919 sources are fully protoized, and rely on standard headers being
3924 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3926 * The MI enabled by default.
3928 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3929 revised and enabled by default. Packages which use GDB as a debugging
3930 engine behind a UI or another front end are encouraged to switch to
3931 using the GDB/MI interface, instead of the old annotations interface
3932 which is now deprecated.
3934 * Support for debugging Pascal programs.
3936 GDB now includes support for debugging Pascal programs. The following
3937 main features are supported:
3939 - Pascal-specific data types such as sets;
3941 - automatic recognition of Pascal sources based on file-name
3944 - Pascal-style display of data types, variables, and functions;
3946 - a Pascal expression parser.
3948 However, some important features are not yet supported.
3950 - Pascal string operations are not supported at all;
3952 - there are some problems with boolean types;
3954 - Pascal type hexadecimal constants are not supported
3955 because they conflict with the internal variables format;
3957 - support for Pascal objects and classes is not full yet;
3959 - unlike Pascal, GDB is case-sensitive for symbol names.
3961 * Changes in completion.
3963 Commands such as `shell', `run' and `set args', which pass arguments
3964 to inferior programs, now complete on file names, similar to what
3965 users expect at the shell prompt.
3967 Commands which accept locations, such as `disassemble', `print',
3968 `breakpoint', `until', etc. now complete on filenames as well as
3969 program symbols. Thus, if you type "break foob TAB", and the source
3970 files linked into the programs include `foobar.c', that file name will
3971 be one of the candidates for completion. However, file names are not
3972 considered for completion after you typed a colon that delimits a file
3973 name from a name of a function in that file, as in "break foo.c:bar".
3975 `set demangle-style' completes on available demangling styles.
3977 * New platform-independent commands:
3979 It is now possible to define a post-hook for a command as well as a
3980 hook that runs before the command. For more details, see the
3981 documentation of `hookpost' in the GDB manual.
3983 * Changes in GNU/Linux native debugging.
3985 Support for debugging multi-threaded programs has been completely
3986 revised for all platforms except m68k and sparc. You can now debug as
3987 many threads as your system allows you to have.
3989 Attach/detach is supported for multi-threaded programs.
3991 Support for SSE registers was added for x86. This doesn't work for
3992 multi-threaded programs though.
3994 * Changes in MIPS configurations.
3996 Multi-arch support is enabled for all MIPS configurations.
3998 GDB can now be built as native debugger on SGI Irix 6.x systems for
3999 debugging n32 executables. (Debugging 64-bit executables is not yet
4002 * Unified support for hardware watchpoints in all x86 configurations.
4004 Most (if not all) native x86 configurations support hardware-assisted
4005 breakpoints and watchpoints in a unified manner. This support
4006 implements debug register sharing between watchpoints, which allows to
4007 put a virtually infinite number of watchpoints on the same address,
4008 and also supports watching regions up to 16 bytes with several debug
4011 The new maintenance command `maintenance show-debug-regs' toggles
4012 debugging print-outs in functions that insert, remove, and test
4013 watchpoints and hardware breakpoints.
4015 * Changes in the DJGPP native configuration.
4017 New command ``info dos sysinfo'' displays assorted information about
4018 the CPU, OS, memory, and DPMI server.
4020 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4021 display information about segment descriptors stored in GDT, LDT, and
4024 New commands ``info dos pde'' and ``info dos pte'' display entries
4025 from Page Directory and Page Tables (for now works with CWSDPMI only).
4026 New command ``info dos address-pte'' displays the Page Table entry for
4027 a given linear address.
4029 GDB can now pass command lines longer than 126 characters to the
4030 program being debugged (requires an update to the libdbg.a library
4031 which is part of the DJGPP development kit).
4033 DWARF2 debug info is now supported.
4035 It is now possible to `step' and `next' through calls to `longjmp'.
4037 * Changes in documentation.
4039 All GDB documentation was converted to GFDL, the GNU Free
4040 Documentation License.
4042 Tracepoints-related commands are now fully documented in the GDB
4045 TUI, the Text-mode User Interface, is now documented in the manual.
4047 Tracepoints-related commands are now fully documented in the GDB
4050 The "GDB Internals" manual now has an index. It also includes
4051 documentation of `ui_out' functions, GDB coding standards, x86
4052 hardware watchpoints, and memory region attributes.
4054 * GDB's version number moved to ``version.in''
4056 The Makefile variable VERSION has been replaced by the file
4057 ``version.in''. People creating GDB distributions should update the
4058 contents of this file.
4062 GUD support is now a standard part of the EMACS distribution.
4064 *** Changes in GDB 5.0:
4066 * Improved support for debugging FP programs on x86 targets
4068 Unified and much-improved support for debugging floating-point
4069 programs on all x86 targets. In particular, ``info float'' now
4070 displays the FP registers in the same format on all x86 targets, with
4071 greater level of detail.
4073 * Improvements and bugfixes in hardware-assisted watchpoints
4075 It is now possible to watch array elements, struct members, and
4076 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4077 on x86 targets no longer erroneously trigger when the address is
4080 * Improvements in the native DJGPP version of GDB
4082 The distribution now includes all the scripts and auxiliary files
4083 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4084 machines ``out of the box''.
4086 The DJGPP version can now debug programs that use signals. It is
4087 possible to catch signals that happened in the debuggee, deliver
4088 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4089 would kill the program being debugged.) Programs that hook hardware
4090 interrupts (keyboard, timer, etc.) can also be debugged.
4092 It is now possible to debug DJGPP programs that redirect their
4093 standard handles or switch them to raw (as opposed to cooked) mode, or
4094 even close them. The command ``run < foo > bar'' works as expected,
4095 and ``info terminal'' reports useful information about the debuggee's
4096 terminal, including raw/cooked mode, redirection, etc.
4098 The DJGPP version now uses termios functions for console I/O, which
4099 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4102 DOS-style file names with drive letters are now fully supported by
4105 It is now possible to debug DJGPP programs that switch their working
4106 directory. It is also possible to rerun the debuggee any number of
4107 times without restarting GDB; thus, you can use the same setup,
4108 breakpoints, etc. for many debugging sessions.
4110 * New native configurations
4112 ARM GNU/Linux arm*-*-linux*
4113 PowerPC GNU/Linux powerpc-*-linux*
4117 Motorola MCore mcore-*-*
4118 x86 VxWorks i[3456]86-*-vxworks*
4119 PowerPC VxWorks powerpc-*-vxworks*
4120 TI TMS320C80 tic80-*-*
4122 * OBSOLETE configurations
4124 Altos 3068 m68*-altos-*
4125 Convex c1-*-*, c2-*-*
4127 ARM RISCix arm-*-* (as host)
4130 Configurations that have been declared obsolete will be commented out,
4131 but the code will be left in place. If there is no activity to revive
4132 these configurations before the next release of GDB, the sources will
4133 be permanently REMOVED.
4135 * Gould support removed
4137 Support for the Gould PowerNode and NP1 has been removed.
4139 * New features for SVR4
4141 On SVR4 native platforms (such as Solaris), if you attach to a process
4142 without first loading a symbol file, GDB will now attempt to locate and
4143 load symbols from the running process's executable file.
4145 * Many C++ enhancements
4147 C++ support has been greatly improved. Overload resolution now works properly
4148 in almost all cases. RTTI support is on the way.
4150 * Remote targets can connect to a sub-program
4152 A popen(3) style serial-device has been added. This device starts a
4153 sub-process (such as a stand-alone simulator) and then communicates
4154 with that. The sub-program to run is specified using the syntax
4155 ``|<program> <args>'' vis:
4157 (gdb) set remotedebug 1
4158 (gdb) target extended-remote |mn10300-elf-sim program-args
4160 * MIPS 64 remote protocol
4162 A long standing bug in the mips64 remote protocol where by GDB
4163 expected certain 32 bit registers (ex SR) to be transfered as 32
4164 instead of 64 bits has been fixed.
4166 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4167 added to provide backward compatibility with older versions of GDB.
4169 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4171 The command ``set remotebinarydownload'' command has been replaced by
4172 ``set remote X-packet''. Other commands in ``set remote'' family
4173 include ``set remote P-packet''.
4175 * Breakpoint commands accept ranges.
4177 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4178 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4179 ``tracepoint passcount'' also accepts a range of tracepoints.
4181 * ``apropos'' command added.
4183 The ``apropos'' command searches through command names and
4184 documentation strings, printing out matches, making it much easier to
4185 try to find a command that does what you are looking for.
4189 A new machine oriented interface (MI) has been added to GDB. This
4190 interface is designed for debug environments running GDB as a separate
4191 process. This is part of the long term libGDB project. See the
4192 "GDB/MI" chapter of the GDB manual for further information. It can be
4193 enabled by configuring with:
4195 .../configure --enable-gdbmi
4197 *** Changes in GDB-4.18:
4199 * New native configurations
4201 HP-UX 10.20 hppa*-*-hpux10.20
4202 HP-UX 11.x hppa*-*-hpux11.0*
4203 M68K GNU/Linux m68*-*-linux*
4207 Fujitsu FR30 fr30-*-elf*
4208 Intel StrongARM strongarm-*-*
4209 Mitsubishi D30V d30v-*-*
4211 * OBSOLETE configurations
4213 Gould PowerNode, NP1 np1-*-*, pn-*-*
4215 Configurations that have been declared obsolete will be commented out,
4216 but the code will be left in place. If there is no activity to revive
4217 these configurations before the next release of GDB, the sources will
4218 be permanently REMOVED.
4222 As a compatibility experiment, GDB's source files buildsym.h and
4223 buildsym.c have been converted to pure standard C, no longer
4224 containing any K&R compatibility code. We believe that all systems in
4225 use today either come with a standard C compiler, or have a GCC port
4226 available. If this is not true, please report the affected
4227 configuration to bug-gdb@gnu.org immediately. See the README file for
4228 information about getting a standard C compiler if you don't have one
4233 GDB now uses readline 2.2.
4235 * set extension-language
4237 You can now control the mapping between filename extensions and source
4238 languages by using the `set extension-language' command. For instance,
4239 you can ask GDB to treat .c files as C++ by saying
4240 set extension-language .c c++
4241 The command `info extensions' lists all of the recognized extensions
4242 and their associated languages.
4244 * Setting processor type for PowerPC and RS/6000
4246 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4247 you can use the `set processor' command to specify what variant of the
4248 PowerPC family you are debugging. The command
4252 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4253 following PowerPC and RS6000 variants:
4255 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4256 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4258 403GC IBM PowerPC 403GC
4259 505 Motorola PowerPC 505
4260 860 Motorola PowerPC 860 or 850
4261 601 Motorola PowerPC 601
4262 602 Motorola PowerPC 602
4263 603 Motorola/IBM PowerPC 603 or 603e
4264 604 Motorola PowerPC 604 or 604e
4265 750 Motorola/IBM PowerPC 750 or 750
4267 At the moment, this command just tells GDB what to name the
4268 special-purpose processor registers. Since almost all the affected
4269 registers are inaccessible to user-level programs, this command is
4270 only useful for remote debugging in its present form.
4274 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4275 more extensive support for HP-UX. Added features include shared
4276 library support, kernel threads and hardware watchpoints for 11.00,
4277 support for HP's ANSI C and C++ compilers, and a compatibility mode
4278 for xdb and dbx commands.
4282 HP's donation includes the new concept of catchpoints, which is a
4283 generalization of the old catch command. On HP-UX, it is now possible
4284 to catch exec, fork, and vfork, as well as library loading.
4286 This means that the existing catch command has changed; its first
4287 argument now specifies the type of catch to be set up. See the
4288 output of "help catch" for a list of catchpoint types.
4290 * Debugging across forks
4292 On HP-UX, you can choose which process to debug when a fork() happens
4297 HP has donated a curses-based terminal user interface (TUI). To get
4298 it, build with --enable-tui. Although this can be enabled for any
4299 configuration, at present it only works for native HP debugging.
4301 * GDB remote protocol additions
4303 A new protocol packet 'X' that writes binary data is now available.
4304 Default behavior is to try 'X', then drop back to 'M' if the stub
4305 fails to respond. The settable variable `remotebinarydownload'
4306 allows explicit control over the use of 'X'.
4308 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4309 full 64-bit address. The command
4311 set remoteaddresssize 32
4313 can be used to revert to the old behaviour. For existing remote stubs
4314 the change should not be noticed, as the additional address information
4317 In order to assist in debugging stubs, you may use the maintenance
4318 command `packet' to send any text string to the stub. For instance,
4320 maint packet heythere
4322 sends the packet "$heythere#<checksum>". Note that it is very easy to
4323 disrupt a debugging session by sending the wrong packet at the wrong
4326 The compare-sections command allows you to compare section data on the
4327 target to what is in the executable file without uploading or
4328 downloading, by comparing CRC checksums.
4330 * Tracing can collect general expressions
4332 You may now collect general expressions at tracepoints. This requires
4333 further additions to the target-side stub; see tracepoint.c and
4334 doc/agentexpr.texi for further details.
4336 * mask-address variable for Mips
4338 For Mips targets, you may control the zeroing of the upper 32 bits of
4339 a 64-bit address by entering `set mask-address on'. This is mainly
4340 of interest to users of embedded R4xxx and R5xxx processors.
4342 * Higher serial baud rates
4344 GDB's serial code now allows you to specify baud rates 57600, 115200,
4345 230400, and 460800 baud. (Note that your host system may not be able
4346 to achieve all of these rates.)
4350 The i960 configuration now includes an initial implementation of a
4351 builtin simulator, contributed by Jim Wilson.
4354 *** Changes in GDB-4.17:
4356 * New native configurations
4358 Alpha GNU/Linux alpha*-*-linux*
4359 Unixware 2.x i[3456]86-unixware2*
4360 Irix 6.x mips*-sgi-irix6*
4361 PowerPC GNU/Linux powerpc-*-linux*
4362 PowerPC Solaris powerpcle-*-solaris*
4363 Sparc GNU/Linux sparc-*-linux*
4364 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4368 Argonaut Risc Chip (ARC) arc-*-*
4369 Hitachi H8/300S h8300*-*-*
4370 Matsushita MN10200 w/simulator mn10200-*-*
4371 Matsushita MN10300 w/simulator mn10300-*-*
4372 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4373 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4374 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4375 Mitsubishi D10V w/simulator d10v-*-*
4376 Mitsubishi M32R/D w/simulator m32r-*-elf*
4377 Tsqware Sparclet sparclet-*-*
4378 NEC V850 w/simulator v850-*-*
4380 * New debugging protocols
4382 ARM with RDI protocol arm*-*-*
4383 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4384 DDB and LSI variants of PMON protocol mips*-*-*
4385 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4386 PowerPC with SDS protocol powerpc{,le}-*-eabi
4387 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4391 All configurations can now understand and use the DWARF 2 debugging
4392 format. The choice is automatic, if the symbol file contains DWARF 2
4397 GDB now includes basic Java language support. This support is
4398 only useful with Java compilers that produce native machine code.
4400 * solib-absolute-prefix and solib-search-path
4402 For SunOS and SVR4 shared libraries, you may now set the prefix for
4403 loading absolute shared library symbol files, and the search path for
4404 locating non-absolute shared library symbol files.
4406 * Live range splitting
4408 GDB can now effectively debug code for which GCC has performed live
4409 range splitting as part of its optimization. See gdb/doc/LRS for
4410 more details on the expected format of the stabs information.
4414 GDB's support for the GNU Hurd, including thread debugging, has been
4415 updated to work with current versions of the Hurd.
4419 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4420 instruction set. ARM GDB automatically detects when Thumb
4421 instructions are in use, and adjusts disassembly and backtracing
4426 GDB's MIPS target configurations now handle the MIP16 16-bit
4431 GDB now includes support for overlays; if an executable has been
4432 linked such that multiple sections are based at the same address, GDB
4433 will decide which section to use for symbolic info. You can choose to
4434 control the decision manually, using overlay commands, or implement
4435 additional target-side support and use "overlay load-target" to bring
4436 in the overlay mapping. Do "help overlay" for more detail.
4440 The command "info symbol <address>" displays information about
4441 the symbol at the specified address.
4445 The standard remote protocol now includes an extension that allows
4446 asynchronous collection and display of trace data. This requires
4447 extensive support in the target-side debugging stub. Tracing mode
4448 includes a new interaction mode in GDB and new commands: see the
4449 file tracepoint.c for more details.
4453 Configurations for embedded MIPS now include a simulator contributed
4454 by Cygnus Solutions. The simulator supports the instruction sets
4455 of most MIPS variants.
4459 Sparc configurations may now include the ERC32 simulator contributed
4460 by the European Space Agency. The simulator is not built into
4461 Sparc targets by default; configure with --enable-sim to include it.
4465 For target configurations that may include multiple variants of a
4466 basic architecture (such as MIPS and SH), you may now set the
4467 architecture explicitly. "set arch" sets, "info arch" lists
4468 the possible architectures.
4470 *** Changes in GDB-4.16:
4472 * New native configurations
4474 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4475 M68K NetBSD m68k-*-netbsd*
4476 PowerPC AIX 4.x powerpc-*-aix*
4477 PowerPC MacOS powerpc-*-macos*
4478 PowerPC Windows NT powerpcle-*-cygwin32
4479 RS/6000 AIX 4.x rs6000-*-aix4*
4483 ARM with RDP protocol arm-*-*
4484 I960 with MON960 i960-*-coff
4485 MIPS VxWorks mips*-*-vxworks*
4486 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4487 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4489 Matra Sparclet sparclet-*-*
4493 The powerpc-eabi configuration now includes the PSIM simulator,
4494 contributed by Andrew Cagney, with assistance from Mike Meissner.
4495 PSIM is a very elaborate model of the PowerPC, including not only
4496 basic instruction set execution, but also details of execution unit
4497 performance and I/O hardware. See sim/ppc/README for more details.
4501 GDB now works with Solaris 2.5.
4503 * Windows 95/NT native
4505 GDB will now work as a native debugger on Windows 95 and Windows NT.
4506 To build it from source, you must use the "gnu-win32" environment,
4507 which uses a DLL to emulate enough of Unix to run the GNU tools.
4508 Further information, binaries, and sources are available at
4509 ftp.cygnus.com, under pub/gnu-win32.
4511 * dont-repeat command
4513 If a user-defined command includes the command `dont-repeat', then the
4514 command will not be repeated if the user just types return. This is
4515 useful if the command is time-consuming to run, so that accidental
4516 extra keystrokes don't run the same command many times.
4518 * Send break instead of ^C
4520 The standard remote protocol now includes an option to send a break
4521 rather than a ^C to the target in order to interrupt it. By default,
4522 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4524 * Remote protocol timeout
4526 The standard remote protocol includes a new variable `remotetimeout'
4527 that allows you to set the number of seconds before GDB gives up trying
4528 to read from the target. The default value is 2.
4530 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4532 By default GDB will automatically keep track of objects as they are
4533 loaded and unloaded by the dynamic linker. By using the command `set
4534 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4535 when shared library events occur, thus allowing you to set breakpoints
4536 in shared libraries which are explicitly loaded by the inferior.
4538 Note this feature does not work on hpux8. On hpux9 you must link
4539 /usr/lib/end.o into your program. This feature should work
4540 automatically on hpux10.
4542 * Irix 5.x hardware watchpoint support
4544 Irix 5 configurations now support the use of hardware watchpoints.
4546 * Mips protocol "SYN garbage limit"
4548 When debugging a Mips target using the `target mips' protocol, you
4549 may set the number of characters that GDB will ignore by setting
4550 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4551 every character. The default value is 1050.
4553 * Recording and replaying remote debug sessions
4555 If you set `remotelogfile' to the name of a file, gdb will write to it
4556 a recording of a remote debug session. This recording may then be
4557 replayed back to gdb using "gdbreplay". See gdbserver/README for
4558 details. This is useful when you have a problem with GDB while doing
4559 remote debugging; you can make a recording of the session and send it
4560 to someone else, who can then recreate the problem.
4562 * Speedups for remote debugging
4564 GDB includes speedups for downloading and stepping MIPS systems using
4565 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4566 and more efficient S-record downloading.
4568 * Memory use reductions and statistics collection
4570 GDB now uses less memory and reports statistics about memory usage.
4571 Try the `maint print statistics' command, for example.
4573 *** Changes in GDB-4.15:
4575 * Psymtabs for XCOFF
4577 The symbol reader for AIX GDB now uses partial symbol tables. This
4578 can greatly improve startup time, especially for large executables.
4580 * Remote targets use caching
4582 Remote targets now use a data cache to speed up communication with the
4583 remote side. The data cache could lead to incorrect results because
4584 it doesn't know about volatile variables, thus making it impossible to
4585 debug targets which use memory mapped I/O devices. `set remotecache
4586 off' turns the the data cache off.
4588 * Remote targets may have threads
4590 The standard remote protocol now includes support for multiple threads
4591 in the target system, using new protocol commands 'H' and 'T'. See
4592 gdb/remote.c for details.
4596 If GDB is configured with `--enable-netrom', then it will include
4597 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4598 acts as though it is a bank of ROM on the target board, but you can
4599 write into it over the network. GDB's support consists only of
4600 support for fast loading into the emulated ROM; to debug, you must use
4601 another protocol, such as standard remote protocol. The usual
4602 sequence is something like
4604 target nrom <netrom-hostname>
4606 target remote <netrom-hostname>:1235
4610 GDB now includes support for the Apple Macintosh, as a host only. It
4611 may be run as either an MPW tool or as a standalone application, and
4612 it can debug through the serial port. All the usual GDB commands are
4613 available, but to the target command, you must supply "serial" as the
4614 device type instead of "/dev/ttyXX". See mpw-README in the main
4615 directory for more information on how to build. The MPW configuration
4616 scripts */mpw-config.in support only a few targets, and only the
4617 mips-idt-ecoff target has been tested.
4621 GDB configuration now uses autoconf. This is not user-visible,
4622 but does simplify configuration and building.
4626 GDB now supports hpux10.
4628 *** Changes in GDB-4.14:
4630 * New native configurations
4632 x86 FreeBSD i[345]86-*-freebsd
4633 x86 NetBSD i[345]86-*-netbsd
4634 NS32k NetBSD ns32k-*-netbsd
4635 Sparc NetBSD sparc-*-netbsd
4639 A29K VxWorks a29k-*-vxworks
4640 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4641 CPU32 EST-300 emulator m68*-*-est*
4642 PowerPC ELF powerpc-*-elf
4645 * Alpha OSF/1 support for procfs
4647 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4648 possible to attach to running processes. As the mounting of the /proc
4649 filesystem is optional on the Alpha, GDB automatically determines
4650 the availability of /proc during startup. This can lead to problems
4651 if /proc is unmounted after GDB has been started.
4653 * Arguments to user-defined commands
4655 User commands may accept up to 10 arguments separated by whitespace.
4656 Arguments are accessed within the user command via $arg0..$arg9. A
4659 print $arg0 + $arg1 + $arg2
4661 To execute the command use:
4664 Defines the command "adder" which prints the sum of its three arguments.
4665 Note the arguments are text substitutions, so they may reference variables,
4666 use complex expressions, or even perform inferior function calls.
4668 * New `if' and `while' commands
4670 This makes it possible to write more sophisticated user-defined
4671 commands. Both commands take a single argument, which is the
4672 expression to evaluate, and must be followed by the commands to
4673 execute, one per line, if the expression is nonzero, the list being
4674 terminated by the word `end'. The `if' command list may include an
4675 `else' word, which causes the following commands to be executed only
4676 if the expression is zero.
4678 * Fortran source language mode
4680 GDB now includes partial support for Fortran 77. It will recognize
4681 Fortran programs and can evaluate a subset of Fortran expressions, but
4682 variables and functions may not be handled correctly. GDB will work
4683 with G77, but does not yet know much about symbols emitted by other
4686 * Better HPUX support
4688 Most debugging facilities now work on dynamic executables for HPPAs
4689 running hpux9 or later. You can attach to running dynamically linked
4690 processes, but by default the dynamic libraries will be read-only, so
4691 for instance you won't be able to put breakpoints in them. To change
4692 that behavior do the following before running the program:
4698 This will cause the libraries to be mapped private and read-write.
4699 To revert to the normal behavior, do this:
4705 You cannot set breakpoints or examine data in the library until after
4706 the library is loaded if the function/data symbols do not have
4709 GDB can now also read debug symbols produced by the HP C compiler on
4710 HPPAs (sorry, no C++, Fortran or 68k support).
4712 * Target byte order now dynamically selectable
4714 You can choose which byte order to use with a target system, via the
4715 commands "set endian big" and "set endian little", and you can see the
4716 current setting by using "show endian". You can also give the command
4717 "set endian auto", in which case GDB will use the byte order
4718 associated with the executable. Currently, only embedded MIPS
4719 configurations support dynamic selection of target byte order.
4721 * New DOS host serial code
4723 This version uses DPMI interrupts to handle buffered I/O, so you
4724 no longer need to run asynctsr when debugging boards connected to
4727 *** Changes in GDB-4.13:
4729 * New "complete" command
4731 This lists all the possible completions for the rest of the line, if it
4732 were to be given as a command itself. This is intended for use by emacs.
4734 * Trailing space optional in prompt
4736 "set prompt" no longer adds a space for you after the prompt you set. This
4737 allows you to set a prompt which ends in a space or one that does not.
4739 * Breakpoint hit counts
4741 "info break" now displays a count of the number of times the breakpoint
4742 has been hit. This is especially useful in conjunction with "ignore"; you
4743 can ignore a large number of breakpoint hits, look at the breakpoint info
4744 to see how many times the breakpoint was hit, then run again, ignoring one
4745 less than that number, and this will get you quickly to the last hit of
4748 * Ability to stop printing at NULL character
4750 "set print null-stop" will cause GDB to stop printing the characters of
4751 an array when the first NULL is encountered. This is useful when large
4752 arrays actually contain only short strings.
4754 * Shared library breakpoints
4756 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4757 breakpoints in shared libraries before the executable is run.
4759 * Hardware watchpoints
4761 There is a new hardware breakpoint for the watch command for sparclite
4762 targets. See gdb/sparclite/hw_breakpoint.note.
4764 Hardware watchpoints are also now supported under GNU/Linux.
4768 Annotations have been added. These are for use with graphical interfaces,
4769 and are still experimental. Currently only gdba.el uses these.
4771 * Improved Irix 5 support
4773 GDB now works properly with Irix 5.2.
4775 * Improved HPPA support
4777 GDB now works properly with the latest GCC and GAS.
4779 * New native configurations
4781 Sequent PTX4 i[34]86-sequent-ptx4
4782 HPPA running OSF/1 hppa*-*-osf*
4783 Atari TT running SVR4 m68*-*-sysv4*
4784 RS/6000 LynxOS rs6000-*-lynxos*
4788 OS/9000 i[34]86-*-os9k
4789 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4792 * Hitachi SH7000 and E7000-PC ICE support
4794 There is now support for communicating with the Hitachi E7000-PC ICE.
4795 This is available automatically when GDB is configured for the SH.
4799 As usual, a variety of small fixes and improvements, both generic
4800 and configuration-specific. See the ChangeLog for more detail.
4802 *** Changes in GDB-4.12:
4804 * Irix 5 is now supported
4808 GDB-4.12 on the HPPA has a number of changes which make it unable
4809 to debug the output from the currently released versions of GCC and
4810 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4811 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4812 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4815 *** Changes in GDB-4.11:
4817 * User visible changes:
4821 The "set remotedebug" option is now consistent between the mips remote
4822 target, remote targets using the gdb-specific protocol, UDI (AMD's
4823 debug protocol for the 29k) and the 88k bug monitor. It is now an
4824 integer specifying a debug level (normally 0 or 1, but 2 means more
4825 debugging info for the mips target).
4827 * DEC Alpha native support
4829 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4830 debug info, but GDB works fairly well with the DEC compiler and should
4831 work with a future GCC release. See the README file for a few
4832 Alpha-specific notes.
4834 * Preliminary thread implementation
4836 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4838 * LynxOS native and target support for 386
4840 This release has been hosted on LynxOS 2.2, and also can be configured
4841 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4844 * Improvements in C++ mangling/demangling.
4846 This release has much better g++ debugging, specifically in name
4847 mangling/demangling, virtual function calls, print virtual table,
4848 call methods, ...etc.
4850 *** Changes in GDB-4.10:
4852 * User visible changes:
4854 Remote debugging using the GDB-specific (`target remote') protocol now
4855 supports the `load' command. This is only useful if you have some
4856 other way of getting the stub to the target system, and you can put it
4857 somewhere in memory where it won't get clobbered by the download.
4859 Filename completion now works.
4861 When run under emacs mode, the "info line" command now causes the
4862 arrow to point to the line specified. Also, "info line" prints
4863 addresses in symbolic form (as well as hex).
4865 All vxworks based targets now support a user settable option, called
4866 vxworks-timeout. This option represents the number of seconds gdb
4867 should wait for responses to rpc's. You might want to use this if
4868 your vxworks target is, perhaps, a slow software simulator or happens
4869 to be on the far side of a thin network line.
4873 This release contains support for using a DEC alpha as a GDB host for
4874 cross debugging. Native alpha debugging is not supported yet.
4877 *** Changes in GDB-4.9:
4881 This is the first GDB release which is accompanied by a matching testsuite.
4882 The testsuite requires installation of dejagnu, which should be available
4883 via ftp from most sites that carry GNU software.
4887 'Cfront' style demangling has had its name changed to 'ARM' style, to
4888 emphasize that it was written from the specifications in the C++ Annotated
4889 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4890 disclaimers, it still generated too much confusion with users attempting to
4891 use gdb with AT&T cfront.
4895 GDB now uses a standard remote interface to a simulator library.
4896 So far, the library contains simulators for the Zilog Z8001/2, the
4897 Hitachi H8/300, H8/500 and Super-H.
4899 * New targets supported
4901 H8/300 simulator h8300-hitachi-hms or h8300hms
4902 H8/500 simulator h8500-hitachi-hms or h8500hms
4903 SH simulator sh-hitachi-hms or sh
4904 Z8000 simulator z8k-zilog-none or z8ksim
4905 IDT MIPS board over serial line mips-idt-ecoff
4907 Cross-debugging to GO32 targets is supported. It requires a custom
4908 version of the i386-stub.c module which is integrated with the
4909 GO32 memory extender.
4911 * New remote protocols
4913 MIPS remote debugging protocol.
4915 * New source languages supported
4917 This version includes preliminary support for Chill, a Pascal like language
4918 used by telecommunications companies. Chill support is also being integrated
4919 into the GNU compiler, but we don't know when it will be publically available.
4922 *** Changes in GDB-4.8:
4924 * HP Precision Architecture supported
4926 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4927 version of this support was available as a set of patches from the
4928 University of Utah. GDB does not support debugging of programs
4929 compiled with the HP compiler, because HP will not document their file
4930 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4931 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4933 Many problems in the preliminary version have been fixed.
4935 * Faster and better demangling
4937 We have improved template demangling and fixed numerous bugs in the GNU style
4938 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4939 character types (wchar_t) are now supported. Demangling of each symbol is now
4940 only done once, and is cached when the symbol table for a file is read in.
4941 This results in a small increase in memory usage for C programs, a moderate
4942 increase in memory usage for C++ programs, and a fantastic speedup in
4945 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4946 from the specifications in the Annotated Reference Manual, which AT&T's
4947 compiler does not actually implement.
4949 * G++ multiple inheritance compiler problem
4951 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4952 inheritance lattices was reworked to properly discover ambiguities. We
4953 recently found an example which causes this new algorithm to fail in a
4954 very subtle way, producing bad debug information for those classes.
4955 The file 'gcc.patch' (in this directory) can be applied to gcc to
4956 circumvent the problem. A future GCC release will contain a complete
4959 The previous G++ debug info problem (mentioned below for the gdb-4.7
4960 release) is fixed in gcc version 2.3.2.
4962 * Improved configure script
4964 The `configure' script will now attempt to guess your system type if
4965 you don't supply a host system type. The old scheme of supplying a
4966 host system triplet is preferable over using this. All the magic is
4967 done in the new `config.guess' script. Examine it for details.
4969 We have also brought our configure script much more in line with the FSF's
4970 version. It now supports the --with-xxx options. In particular,
4971 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4972 The resulting GDB will not be able to read arbitrary object file formats --
4973 only the format ``expected'' to be used on the configured target system.
4974 We hope to make this the default in a future release.
4976 * Documentation improvements
4978 There's new internal documentation on how to modify GDB, and how to
4979 produce clean changes to the code. We implore people to read it
4980 before submitting changes.
4982 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4983 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4984 `info' files are also provided. To build `info' files from scratch,
4985 you will need the latest `makeinfo' release, which will be available in
4986 a future texinfo-X.Y release.
4988 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4989 We're not sure exactly which versions have this problem, but it has
4990 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4991 or better. If that isn't possible, there is a patch in
4992 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4993 around this problem.
4997 GDB now supports array constants that can be used in expressions typed in by
4998 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4999 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5002 The new directory `gdb/sparclite' contains a program that demonstrates
5003 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5005 * New native hosts supported
5007 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5008 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5010 * New targets supported
5012 AMD 29k family via UDI a29k-amd-udi or udi29k
5014 * New file formats supported
5016 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5017 HPUX core files, and SCO 3.2v2 core files.
5021 Attaching to processes now works again; thanks for the many bug reports.
5023 We have also stomped on a bunch of core dumps caused by
5024 printf_filtered("%s") problems.
5026 We eliminated a copyright problem on the rpc and ptrace header files
5027 for VxWorks, which was discovered at the last minute during the 4.7
5028 release. You should now be able to build a VxWorks GDB.
5030 You can now interrupt gdb while an attached process is running. This
5031 will cause the attached process to stop, and give control back to GDB.
5033 We fixed problems caused by using too many file descriptors
5034 for reading symbols from object files and libraries. This was
5035 especially a problem for programs that used many (~100) shared
5038 The `step' command now only enters a subroutine if there is line number
5039 information for the subroutine. Otherwise it acts like the `next'
5040 command. Previously, `step' would enter subroutines if there was
5041 any debugging information about the routine. This avoids problems
5042 when using `cc -g1' on MIPS machines.
5044 * Internal improvements
5046 GDB's internal interfaces have been improved to make it easier to support
5047 debugging of multiple languages in the future.
5049 GDB now uses a common structure for symbol information internally.
5050 Minimal symbols (derived from linkage symbols in object files), partial
5051 symbols (from a quick scan of debug information), and full symbols
5052 contain a common subset of information, making it easier to write
5053 shared code that handles any of them.
5055 * New command line options
5057 We now accept --silent as an alias for --quiet.
5061 The memory-mapped-malloc library is now licensed under the GNU Library
5062 General Public License.
5064 *** Changes in GDB-4.7:
5066 * Host/native/target split
5068 GDB has had some major internal surgery to untangle the support for
5069 hosts and remote targets. Now, when you configure GDB for a remote
5070 target, it will no longer load in all of the support for debugging
5071 local programs on the host. When fully completed and tested, this will
5072 ensure that arbitrary host/target combinations are possible.
5074 The primary conceptual shift is to separate the non-portable code in
5075 GDB into three categories. Host specific code is required any time GDB
5076 is compiled on that host, regardless of the target. Target specific
5077 code relates to the peculiarities of the target, but can be compiled on
5078 any host. Native specific code is everything else: it can only be
5079 built when the host and target are the same system. Child process
5080 handling and core file support are two common `native' examples.
5082 GDB's use of /proc for controlling Unix child processes is now cleaner.
5083 It has been split out into a single module under the `target_ops' vector,
5084 plus two native-dependent functions for each system that uses /proc.
5086 * New hosts supported
5088 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5089 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5090 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5092 * New targets supported
5094 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5095 68030 and CPU32 m68030-*-*, m68332-*-*
5097 * New native hosts supported
5099 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5100 (386bsd is not well tested yet)
5101 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5103 * New file formats supported
5105 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5106 supports reading of `a.out.adobe' object files, which are an a.out
5107 format extended with minimal information about multiple sections.
5111 `show copying' is the same as the old `info copying'.
5112 `show warranty' is the same as `info warrantee'.
5113 These were renamed for consistency. The old commands continue to work.
5115 `info handle' is a new alias for `info signals'.
5117 You can now define pre-command hooks, which attach arbitrary command
5118 scripts to any command. The commands in the hook will be executed
5119 prior to the user's command. You can also create a hook which will be
5120 executed whenever the program stops. See gdb.texinfo.
5124 We now deal with Cfront style name mangling, and can even extract type
5125 info from mangled symbols. GDB can automatically figure out which
5126 symbol mangling style your C++ compiler uses.
5128 Calling of methods and virtual functions has been improved as well.
5132 The crash that occured when debugging Sun Ansi-C compiled binaries is
5133 fixed. This was due to mishandling of the extra N_SO stabs output
5136 We also finally got Ultrix 4.2 running in house, and fixed core file
5137 support, with help from a dozen people on the net.
5139 John M. Farrell discovered that the reason that single-stepping was so
5140 slow on all of the Mips based platforms (primarily SGI and DEC) was
5141 that we were trying to demangle and lookup a symbol used for internal
5142 purposes on every instruction that was being stepped through. Changing
5143 the name of that symbol so that it couldn't be mistaken for a C++
5144 mangled symbol sped things up a great deal.
5146 Rich Pixley sped up symbol lookups in general by getting much smarter
5147 about when C++ symbol mangling is necessary. This should make symbol
5148 completion (TAB on the command line) much faster. It's not as fast as
5149 we'd like, but it's significantly faster than gdb-4.6.
5153 A new user controllable variable 'call_scratch_address' can
5154 specify the location of a scratch area to be used when GDB
5155 calls a function in the target. This is necessary because the
5156 usual method of putting the scratch area on the stack does not work
5157 in systems that have separate instruction and data spaces.
5159 We integrated changes to support the 29k UDI (Universal Debugger
5160 Interface), but discovered at the last minute that we didn't have all
5161 of the appropriate copyright paperwork. We are working with AMD to
5162 resolve this, and hope to have it available soon.
5166 We have sped up the remote serial line protocol, especially for targets
5167 with lots of registers. It now supports a new `expedited status' ('T')
5168 message which can be used in place of the existing 'S' status message.
5169 This allows the remote stub to send only the registers that GDB
5170 needs to make a quick decision about single-stepping or conditional
5171 breakpoints, eliminating the need to fetch the entire register set for
5172 each instruction being stepped through.
5174 The GDB remote serial protocol now implements a write-through cache for
5175 registers, only re-reading the registers if the target has run.
5177 There is also a new remote serial stub for SPARC processors. You can
5178 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5179 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5180 processor with a serial port.
5184 Configure.in files have become much easier to read and modify. A new
5185 `table driven' format makes it more obvious what configurations are
5186 supported, and what files each one uses.
5190 There is a new opcodes library which will eventually contain all of the
5191 disassembly routines and opcode tables. At present, it only contains
5192 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5193 disassembler (binutils/objdump) to share these routines.
5195 The libiberty library is now copylefted under the GNU Library General
5196 Public License. This allows more liberal use, and was done so libg++
5197 can use it. This makes no difference to GDB, since the Library License
5198 grants all the rights from the General Public License.
5202 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5203 reference to the stabs symbol info used by the debugger. It is (as far
5204 as we know) the only published document on this fascinating topic. We
5205 encourage you to read it, compare it to the stabs information on your
5206 system, and send improvements on the document in general (to
5207 bug-gdb@prep.ai.mit.edu).
5209 And, of course, many bugs have been fixed.
5212 *** Changes in GDB-4.6:
5214 * Better support for C++ function names
5216 GDB now accepts as input the "demangled form" of C++ overloaded function
5217 names and member function names, and can do command completion on such names
5218 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5219 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5220 Make use of command completion, it is your friend.
5222 GDB also now accepts a variety of C++ mangled symbol formats. They are
5223 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5224 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5225 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5226 for the list of formats.
5228 * G++ symbol mangling problem
5230 Recent versions of gcc have a bug in how they emit debugging information for
5231 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5232 directory) can be applied to gcc to fix the problem. Alternatively, if you
5233 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5234 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5235 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5238 * New 'maintenance' command
5240 All of the commands related to hacking GDB internals have been moved out of
5241 the main command set, and now live behind the 'maintenance' command. This
5242 can also be abbreviated as 'mt'. The following changes were made:
5244 dump-me -> maintenance dump-me
5245 info all-breakpoints -> maintenance info breakpoints
5246 printmsyms -> maintenance print msyms
5247 printobjfiles -> maintenance print objfiles
5248 printpsyms -> maintenance print psymbols
5249 printsyms -> maintenance print symbols
5251 The following commands are new:
5253 maintenance demangle Call internal GDB demangler routine to
5254 demangle a C++ link name and prints the result.
5255 maintenance print type Print a type chain for a given symbol
5257 * Change to .gdbinit file processing
5259 We now read the $HOME/.gdbinit file before processing the argv arguments
5260 (e.g. reading symbol files or core files). This allows global parameters to
5261 be set, which will apply during the symbol reading. The ./.gdbinit is still
5262 read after argv processing.
5264 * New hosts supported
5266 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5268 GNU/Linux support i386-unknown-linux or linux
5270 We are also including code to support the HP/PA running BSD and HPUX. This
5271 is almost guaranteed not to work, as we didn't have time to test or build it
5272 for this release. We are including it so that the more adventurous (or
5273 masochistic) of you can play with it. We also had major problems with the
5274 fact that the compiler that we got from HP doesn't support the -g option.
5277 * New targets supported
5279 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5281 * More smarts about finding #include files
5283 GDB now remembers the compilation directory for all include files, and for
5284 all files from which C is generated (like yacc and lex sources). This
5285 greatly improves GDB's ability to find yacc/lex sources, and include files,
5286 especially if you are debugging your program from a directory different from
5287 the one that contains your sources.
5289 We also fixed a bug which caused difficulty with listing and setting
5290 breakpoints in include files which contain C code. (In the past, you had to
5291 try twice in order to list an include file that you hadn't looked at before.)
5293 * Interesting infernals change
5295 GDB now deals with arbitrary numbers of sections, where the symbols for each
5296 section must be relocated relative to that section's landing place in the
5297 target's address space. This work was needed to support ELF with embedded
5298 stabs used by Solaris-2.0.
5300 * Bug fixes (of course!)
5302 There have been loads of fixes for the following things:
5303 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5304 i960, stabs, DOS(GO32), procfs, etc...
5306 See the ChangeLog for details.
5308 *** Changes in GDB-4.5:
5310 * New machines supported (host and target)
5312 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5314 SGI Irix-4.x mips-sgi-irix4 or iris4
5316 * New malloc package
5318 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5319 Mmalloc is capable of handling mutiple heaps of memory. It is also
5320 capable of saving a heap to a file, and then mapping it back in later.
5321 This can be used to greatly speedup the startup of GDB by using a
5322 pre-parsed symbol table which lives in a mmalloc managed heap. For
5323 more details, please read mmalloc/mmalloc.texi.
5327 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5328 'help info proc' for details.
5330 * MIPS ecoff symbol table format
5332 The code that reads MIPS symbol table format is now supported on all hosts.
5333 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5336 * File name changes for MS-DOS
5338 Many files in the config directories have been renamed to make it easier to
5339 support GDB on MS-DOSe systems (which have very restrictive file name
5340 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5341 environment) is close to working but has some remaining problems. Note
5342 that debugging of DOS programs is not supported, due to limitations
5343 in the ``operating system'', but it can be used to host cross-debugging.
5345 * Cross byte order fixes
5347 Many fixes have been made to support cross debugging of Sparc and MIPS
5348 targets from hosts whose byte order differs.
5350 * New -mapped and -readnow options
5352 If memory-mapped files are available on your system through the 'mmap'
5353 system call, you can use the -mapped option on the `file' or
5354 `symbol-file' commands to cause GDB to write the symbols from your
5355 program into a reusable file. If the program you are debugging is
5356 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5357 Future GDB debugging sessions will notice the presence of this file,
5358 and will quickly map in symbol information from it, rather than reading
5359 the symbol table from the executable program. Using the '-mapped'
5360 option in a GDB `file' or `symbol-file' command has the same effect as
5361 starting GDB with the '-mapped' command-line option.
5363 You can cause GDB to read the entire symbol table immediately by using
5364 the '-readnow' option with any of the commands that load symbol table
5365 information (or on the GDB command line). This makes the command
5366 slower, but makes future operations faster.
5368 The -mapped and -readnow options are typically combined in order to
5369 build a `fred.syms' file that contains complete symbol information.
5370 A simple GDB invocation to do nothing but build a `.syms' file for future
5373 gdb -batch -nx -mapped -readnow programname
5375 The `.syms' file is specific to the host machine on which GDB is run.
5376 It holds an exact image of GDB's internal symbol table. It cannot be
5377 shared across multiple host platforms.
5379 * longjmp() handling
5381 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5382 siglongjmp() without losing control. This feature has not yet been ported to
5383 all systems. It currently works on many 386 platforms, all MIPS-based
5384 platforms (SGI, DECstation, etc), and Sun3/4.
5388 Preliminary work has been put in to support the new Solaris OS from Sun. At
5389 this time, it can control and debug processes, but it is not capable of
5394 As always, many many bug fixes. The major areas were with g++, and mipsread.
5395 People using the MIPS-based platforms should experience fewer mysterious
5396 crashes and trashed symbol tables.
5398 *** Changes in GDB-4.4:
5400 * New machines supported (host and target)
5402 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5404 BSD Reno on Vax vax-dec-bsd
5405 Ultrix on Vax vax-dec-ultrix
5407 * New machines supported (target)
5409 AMD 29000 embedded, using EBMON a29k-none-none
5413 GDB continues to improve its handling of C++. `References' work better.
5414 The demangler has also been improved, and now deals with symbols mangled as
5415 per the Annotated C++ Reference Guide.
5417 GDB also now handles `stabs' symbol information embedded in MIPS
5418 `ecoff' symbol tables. Since the ecoff format was not easily
5419 extensible to handle new languages such as C++, this appeared to be a
5420 good way to put C++ debugging info into MIPS binaries. This option
5421 will be supported in the GNU C compiler, version 2, when it is
5424 * New features for SVR4
5426 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5427 shared libraries. Debugging dynamically linked programs should present
5428 only minor differences from debugging statically linked programs.
5430 The `info proc' command will print out information about any process
5431 on an SVR4 system (including the one you are debugging). At the moment,
5432 it prints the address mappings of the process.
5434 If you bring up GDB on another SVR4 system, please send mail to
5435 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5437 * Better dynamic linking support in SunOS
5439 Reading symbols from shared libraries which contain debugging symbols
5440 now works properly. However, there remain issues such as automatic
5441 skipping of `transfer vector' code during function calls, which
5442 make it harder to debug code in a shared library, than to debug the
5443 same code linked statically.
5447 GDB is now using the latest `getopt' routines from the FSF. This
5448 version accepts the -- prefix for options with long names. GDB will
5449 continue to accept the old forms (-option and +option) as well.
5450 Various single letter abbreviations for options have been explicity
5451 added to the option table so that they won't get overshadowed in the
5452 future by other options that begin with the same letter.
5456 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5457 Many assorted bugs have been handled. Many more remain to be handled.
5458 See the various ChangeLog files (primarily in gdb and bfd) for details.
5461 *** Changes in GDB-4.3:
5463 * New machines supported (host and target)
5465 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5466 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5467 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5469 * Almost SCO Unix support
5471 We had hoped to support:
5472 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5473 (except for core file support), but we discovered very late in the release
5474 that it has problems with process groups that render gdb unusable. Sorry
5475 about that. I encourage people to fix it and post the fixes.
5477 * Preliminary ELF and DWARF support
5479 GDB can read ELF object files on System V Release 4, and can handle
5480 debugging records for C, in DWARF format, in ELF files. This support
5481 is preliminary. If you bring up GDB on another SVR4 system, please
5482 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5487 GDB now uses the latest `readline' library. One user-visible change
5488 is that two tabs will list possible command completions, which previously
5489 required typing M-? (meta-question mark, or ESC ?).
5493 The `stepi' bug that many of you noticed has been squashed.
5494 Many bugs in C++ have been handled. Many more remain to be handled.
5495 See the various ChangeLog files (primarily in gdb and bfd) for details.
5497 * State of the MIPS world (in case you wondered):
5499 GDB can understand the symbol tables emitted by the compilers
5500 supplied by most vendors of MIPS-based machines, including DEC. These
5501 symbol tables are in a format that essentially nobody else uses.
5503 Some versions of gcc come with an assembler post-processor called
5504 mips-tfile. This program is required if you want to do source-level
5505 debugging of gcc-compiled programs. I believe FSF does not ship
5506 mips-tfile with gcc version 1, but it will eventually come with gcc
5509 Debugging of g++ output remains a problem. g++ version 1.xx does not
5510 really support it at all. (If you're lucky, you should be able to get
5511 line numbers and stack traces to work, but no parameters or local
5512 variables.) With some work it should be possible to improve the
5515 When gcc version 2 is released, you will have somewhat better luck.
5516 However, even then you will get confusing results for inheritance and
5519 We will eventually provide full debugging of g++ output on
5520 DECstations. This will probably involve some kind of stabs-in-ecoff
5521 encapulation, but the details have not been worked out yet.
5524 *** Changes in GDB-4.2:
5526 * Improved configuration
5528 Only one copy of `configure' exists now, and it is not self-modifying.
5529 Porting BFD is simpler.
5533 The `step' and `next' commands now only stop at the first instruction
5534 of a source line. This prevents the multiple stops that used to occur
5535 in switch statements, for-loops, etc. `Step' continues to stop if a
5536 function that has debugging information is called within the line.
5540 Lots of small bugs fixed. More remain.
5542 * New host supported (not target)
5544 Intel 386 PC clone running Mach i386-none-mach
5547 *** Changes in GDB-4.1:
5549 * Multiple source language support
5551 GDB now has internal scaffolding to handle several source languages.
5552 It determines the type of each source file from its filename extension,
5553 and will switch expression parsing and number formatting to match the
5554 language of the function in the currently selected stack frame.
5555 You can also specifically set the language to be used, with
5556 `set language c' or `set language modula-2'.
5560 GDB now has preliminary support for the GNU Modula-2 compiler,
5561 currently under development at the State University of New York at
5562 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5563 continue through the fall of 1991 and into 1992.
5565 Other Modula-2 compilers are currently not supported, and attempting to
5566 debug programs compiled with them will likely result in an error as the
5567 symbol table is read. Feel free to work on it, though!
5569 There are hooks in GDB for strict type checking and range checking,
5570 in the `Modula-2 philosophy', but they do not currently work.
5574 GDB can now write to executable and core files (e.g. patch
5575 a variable's value). You must turn this switch on, specify
5576 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5577 by assigning a new value to a variable. Modifications take
5580 * Automatic SunOS shared library reading
5582 When you run your program, GDB automatically determines where its
5583 shared libraries (if any) have been loaded, and reads their symbols.
5584 The `share' command is no longer needed. This also works when
5585 examining core files.
5589 You can specify the number of lines that the `list' command shows.
5592 * New machines supported (host and target)
5594 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5595 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5596 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5598 * New hosts supported (not targets)
5600 IBM RT/PC: romp-ibm-aix or rtpc
5602 * New targets supported (not hosts)
5604 AMD 29000 embedded with COFF a29k-none-coff
5605 AMD 29000 embedded with a.out a29k-none-aout
5606 Ultracomputer remote kernel debug a29k-nyu-kern
5608 * New remote interfaces
5614 *** Changes in GDB-4.0:
5618 Wide output is wrapped at good places to make the output more readable.
5620 Gdb now supports cross-debugging from a host machine of one type to a
5621 target machine of another type. Communication with the target system
5622 is over serial lines. The ``target'' command handles connecting to the
5623 remote system; the ``load'' command will download a program into the
5624 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5625 also supports debugging of realtime processes running under VxWorks,
5626 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5627 stub on the target system.
5629 New CPUs supported include the AMD 29000 and Intel 960.
5631 GDB now reads object files and symbol tables via a ``binary file''
5632 library, which allows a single copy of GDB to debug programs of multiple
5633 object file types such as a.out and coff.
5635 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5636 refcard.dvi and refcard.ps are available to format it).
5639 * Control-Variable user interface simplified
5641 All variables that control the operation of the debugger can be set
5642 by the ``set'' command, and displayed by the ``show'' command.
5644 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5645 ``Show prompt'' produces the response:
5646 Gdb's prompt is new-gdb=>.
5648 What follows are the NEW set commands. The command ``help set'' will
5649 print a complete list of old and new set commands. ``help set FOO''
5650 will give a longer description of the variable FOO. ``show'' will show
5651 all of the variable descriptions and their current settings.
5653 confirm on/off: Enables warning questions for operations that are
5654 hard to recover from, e.g. rerunning the program while
5655 it is already running. Default is ON.
5657 editing on/off: Enables EMACS style command line editing
5658 of input. Previous lines can be recalled with
5659 control-P, the current line can be edited with control-B,
5660 you can search for commands with control-R, etc.
5663 history filename NAME: NAME is where the gdb command history
5664 will be stored. The default is .gdb_history,
5665 or the value of the environment variable
5668 history size N: The size, in commands, of the command history. The
5669 default is 256, or the value of the environment variable
5672 history save on/off: If this value is set to ON, the history file will
5673 be saved after exiting gdb. If set to OFF, the
5674 file will not be saved. The default is OFF.
5676 history expansion on/off: If this value is set to ON, then csh-like
5677 history expansion will be performed on
5678 command line input. The default is OFF.
5680 radix N: Sets the default radix for input and output. It can be set
5681 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5682 in the current radix, so "set radix 10" is always a no-op.
5684 height N: This integer value is the number of lines on a page. Default
5685 is 24, the current `stty rows'' setting, or the ``li#''
5686 setting from the termcap entry matching the environment
5689 width N: This integer value is the number of characters on a line.
5690 Default is 80, the current `stty cols'' setting, or the ``co#''
5691 setting from the termcap entry matching the environment
5694 Note: ``set screensize'' is obsolete. Use ``set height'' and
5695 ``set width'' instead.
5697 print address on/off: Print memory addresses in various command displays,
5698 such as stack traces and structure values. Gdb looks
5699 more ``symbolic'' if you turn this off; it looks more
5700 ``machine level'' with it on. Default is ON.
5702 print array on/off: Prettyprint arrays. New convenient format! Default
5705 print demangle on/off: Print C++ symbols in "source" form if on,
5708 print asm-demangle on/off: Same, for assembler level printouts
5711 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5714 * Support for Epoch Environment.
5716 The epoch environment is a version of Emacs v18 with windowing. One
5717 new command, ``inspect'', is identical to ``print'', except that if you
5718 are running in the epoch environment, the value is printed in its own
5722 * Support for Shared Libraries
5724 GDB can now debug programs and core files that use SunOS shared libraries.
5725 Symbols from a shared library cannot be referenced
5726 before the shared library has been linked with the program (this
5727 happens after you type ``run'' and before the function main() is entered).
5728 At any time after this linking (including when examining core files
5729 from dynamically linked programs), gdb reads the symbols from each
5730 shared library when you type the ``sharedlibrary'' command.
5731 It can be abbreviated ``share''.
5733 sharedlibrary REGEXP: Load shared object library symbols for files
5734 matching a unix regular expression. No argument
5735 indicates to load symbols for all shared libraries.
5737 info sharedlibrary: Status of loaded shared libraries.
5742 A watchpoint stops execution of a program whenever the value of an
5743 expression changes. Checking for this slows down execution
5744 tremendously whenever you are in the scope of the expression, but is
5745 quite useful for catching tough ``bit-spreader'' or pointer misuse
5746 problems. Some machines such as the 386 have hardware for doing this
5747 more quickly, and future versions of gdb will use this hardware.
5749 watch EXP: Set a watchpoint (breakpoint) for an expression.
5751 info watchpoints: Information about your watchpoints.
5753 delete N: Deletes watchpoint number N (same as breakpoints).
5754 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5755 enable N: Re-enables watchpoint number N (same as breakpoints).
5758 * C++ multiple inheritance
5760 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5763 * C++ exception handling
5765 Gdb now supports limited C++ exception handling. Besides the existing
5766 ability to breakpoint on an exception handler, gdb can breakpoint on
5767 the raising of an exception (before the stack is peeled back to the
5770 catch FOO: If there is a FOO exception handler in the dynamic scope,
5771 set a breakpoint to catch exceptions which may be raised there.
5772 Multiple exceptions (``catch foo bar baz'') may be caught.
5774 info catch: Lists all exceptions which may be caught in the
5775 current stack frame.
5778 * Minor command changes
5780 The command ``call func (arg, arg, ...)'' now acts like the print
5781 command, except it does not print or save a value if the function's result
5782 is void. This is similar to dbx usage.
5784 The ``up'' and ``down'' commands now always print the frame they end up
5785 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5786 frames without printing.
5788 * New directory command
5790 'dir' now adds directories to the FRONT of the source search path.
5791 The path starts off empty. Source files that contain debug information
5792 about the directory in which they were compiled can be found even
5793 with an empty path; Sun CC and GCC include this information. If GDB can't
5794 find your source file in the current directory, type "dir .".
5796 * Configuring GDB for compilation
5798 For normal use, type ``./configure host''. See README or gdb.texinfo
5801 GDB now handles cross debugging. If you are remotely debugging between
5802 two different machines, type ``./configure host -target=targ''.
5803 Host is the machine where GDB will run; targ is the machine
5804 where the program that you are debugging will run.