1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.6
8 ** Frame filters and frame decorators have been added.
12 Nios II ELF nios2*-*-elf
13 Nios II GNU/Linux nios2*-*-linux
17 Like "catch throw", but catches a re-thrown exception.
20 Display the details of GDB configure-time options.
22 maint set|show per-command
23 maint set|show per-command space
24 maint set|show per-command time
25 maint set|show per-command symtab
26 Enable display of per-command gdb resource usage.
30 set remote trace-status-packet
31 show remote trace-status-packet
32 Set/show the use of remote protocol qTStatus packet.
36 Control display of debugging messages related to Nios II targets.
38 * You can now use a literal value 'unlimited' for options that
39 interpret 0 or -1 as meaning "unlimited". E.g., "set
40 trace-buffer-size unlimited" is now an alias for "set
41 trace-buffer-size -1" and "set height unlimited" is now an alias for
44 * New command-line options
46 Display the details of GDB configure-time options.
48 * The command 'tsave' can now support new option '-ctf' to save trace
49 buffer in Common Trace Format.
51 * Newly installed $prefix/bin/gcore acts as a shell interface for the
54 * GDB now implements the the C++ 'typeid' operator.
56 * The new convenience variable $_exception holds the exception being
57 thrown or caught at an exception-related catchpoint.
59 * The exception-related catchpoints, like "catch throw", now accept a
60 regular expression which can be used to filter exceptions by type.
64 ** The -trace-save MI command can optionally save trace buffer in Common
67 *** Changes in GDB 7.6
69 * Target record has been renamed to record-full.
70 Record/replay is now enabled with the "record full" command.
71 This also affects settings that are associated with full record/replay
72 that have been moved from "set/show record" to "set/show record full":
74 set|show record full insn-number-max
75 set|show record full stop-at-limit
76 set|show record full memory-query
78 * A new record target "record-btrace" has been added. The new target
79 uses hardware support to record the control-flow of a process. It
80 does not support replaying the execution, but it implements the
81 below new commands for investigating the recorded execution log.
82 This new recording method can be enabled using:
86 The "record-btrace" target is only available on Intel Atom processors
87 and requires a Linux kernel 2.6.32 or later.
89 * Two new commands have been added for record/replay to give information
90 about the recorded execution without having to replay the execution.
91 The commands are only supported by "record btrace".
93 record instruction-history prints the execution history at
94 instruction granularity
96 record function-call-history prints the execution history at
99 * New native configurations
101 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
102 FreeBSD/powerpc powerpc*-*-freebsd
103 x86_64/Cygwin x86_64-*-cygwin*
104 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
108 ARM AArch64 aarch64*-*-elf
109 ARM AArch64 GNU/Linux aarch64*-*-linux
110 Lynx 178 PowerPC powerpc-*-lynx*178
111 x86_64/Cygwin x86_64-*-cygwin*
112 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
114 * If the configured location of system.gdbinit file (as given by the
115 --with-system-gdbinit option at configure time) is in the
116 data-directory (as specified by --with-gdb-datadir at configure
117 time) or in one of its subdirectories, then GDB will look for the
118 system-wide init file in the directory specified by the
119 --data-directory command-line option.
121 * New command line options:
123 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
124 other initialization files, unlike -nx which disables all of them.
126 * Removed command line options
128 -epoch This was used by the gdb mode in Epoch, an ancient fork of
131 * The 'ptype' and 'whatis' commands now accept an argument to control
134 * 'info proc' now works on some core files.
138 ** Vectors can be created with gdb.Type.vector.
140 ** Python's atexit.register now works in GDB.
142 ** Types can be pretty-printed via a Python API.
144 ** Python 3 is now supported (in addition to Python 2.4 or later)
146 ** New class gdb.Architecture exposes GDB's internal representation
147 of architecture in the Python API.
149 ** New method Frame.architecture returns the gdb.Architecture object
150 corresponding to the frame's architecture.
152 * New Python-based convenience functions:
154 ** $_memeq(buf1, buf2, length)
155 ** $_streq(str1, str2)
157 ** $_regex(str, regex)
159 * The 'cd' command now defaults to using '~' (the home directory) if not
162 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
163 default for GCC since November 2000.
165 * The command 'forward-search' can now be abbreviated as 'fo'.
167 * The command 'info tracepoints' can now display 'installed on target'
168 or 'not installed on target' for each non-pending location of tracepoint.
170 * New configure options
172 --enable-libmcheck/--disable-libmcheck
173 By default, development versions are built with -lmcheck on hosts
174 that support it, in order to help track memory corruption issues.
175 Release versions, on the other hand, are built without -lmcheck
176 by default. The --enable-libmcheck/--disable-libmcheck configure
177 options allow the user to override that default.
178 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
179 This configure option allows the user to build GDB with
180 libbabeltrace using which GDB can read Common Trace Format data.
182 * New commands (for set/show, see "New options" below)
185 Catch signals. This is similar to "handle", but allows commands and
186 conditions to be attached.
189 List the BFDs known to GDB.
191 python-interactive [command]
193 Start a Python interactive prompt, or evaluate the optional command
194 and print the result of expressions.
197 "py" is a new alias for "python".
199 enable type-printer [name]...
200 disable type-printer [name]...
201 Enable or disable type printers.
205 ** For the Renesas Super-H architecture, the "regs" command has been removed
206 (has been deprecated in GDB 7.5), and "info all-registers" should be used
211 set print type methods (on|off)
212 show print type methods
213 Control whether method declarations are displayed by "ptype".
214 The default is to show them.
216 set print type typedefs (on|off)
217 show print type typedefs
218 Control whether typedef definitions are displayed by "ptype".
219 The default is to show them.
221 set filename-display basename|relative|absolute
222 show filename-display
223 Control the way in which filenames is displayed.
224 The default is "relative", which preserves previous behavior.
226 set trace-buffer-size
227 show trace-buffer-size
228 Request target to change the size of trace buffer.
230 set remote trace-buffer-size-packet auto|on|off
231 show remote trace-buffer-size-packet
232 Control the use of the remote protocol `QTBuffer:size' packet.
236 Control display of debugging messages related to ARM AArch64.
239 set debug coff-pe-read
240 show debug coff-pe-read
241 Control display of debugging messages related to reading of COFF/PE
246 Control display of debugging messages related to Mach-O symbols
249 set debug notification
250 show debug notification
251 Control display of debugging info for async remote notification.
255 ** Command parameter changes are now notified using new async record
256 "=cmd-param-changed".
257 ** Trace frame changes caused by command "tfind" are now notified using
258 new async record "=traceframe-changed".
259 ** The creation, deletion and modification of trace state variables
260 are now notified using new async records "=tsv-created",
261 "=tsv-deleted" and "=tsv-modified".
262 ** The start and stop of process record are now notified using new
263 async record "=record-started" and "=record-stopped".
264 ** Memory changes are now notified using new async record
266 ** The data-disassemble command response will include a "fullname" field
267 containing the absolute file name when source has been requested.
268 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
269 command, to allow pattern filling of memory areas.
270 ** New commands "-catch-load"/"-catch-unload" added for intercepting
271 library load/unload events.
272 ** The response to breakpoint commands and breakpoint async records
273 includes an "installed" field containing a boolean state about each
274 non-pending tracepoint location is whether installed on target or not.
275 ** Output of the "-trace-status" command includes a "trace-file" field
276 containing the name of the trace file being examined. This field is
277 optional, and only present when examining a trace file.
278 ** The "fullname" field is now always present along with the "file" field,
279 even if the file cannot be found by GDB.
281 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
282 You must have the LZMA library available when configuring GDB for this
283 feature to be enabled. For more information, see:
284 http://fedoraproject.org/wiki/Features/MiniDebugInfo
289 Set the size of trace buffer. The remote stub reports support for this
290 packet to gdb's qSupported query.
293 Enable Branch Trace Store (BTS)-based branch tracing for the current
294 thread. The remote stub reports support for this packet to gdb's
298 Disable branch tracing for the current thread. The remote stub reports
299 support for this packet to gdb's qSupported query.
302 Read the traced branches for the current thread. The remote stub
303 reports support for this packet to gdb's qSupported query.
305 *** Changes in GDB 7.5
307 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
308 for more x32 ABI info.
310 * GDB now supports access to MIPS DSP registers on Linux targets.
312 * GDB now supports debugging microMIPS binaries.
314 * The "info os" command on GNU/Linux can now display information on
315 several new classes of objects managed by the operating system:
316 "info os procgroups" lists process groups
317 "info os files" lists file descriptors
318 "info os sockets" lists internet-domain sockets
319 "info os shm" lists shared-memory regions
320 "info os semaphores" lists semaphores
321 "info os msg" lists message queues
322 "info os modules" lists loaded kernel modules
324 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
325 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
326 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
327 options and inspect the probe arguments using the new $_probe_arg family
328 of convenience variables. You can obtain more information about SystemTap
329 in <http://sourceware.org/systemtap/>.
331 * GDB now supports reversible debugging on ARM, it allows you to
332 debug basic ARM and THUMB instructions, and provides
333 record/replay support.
335 * The option "symbol-reloading" has been deleted as it is no longer used.
339 ** GDB commands implemented in Python can now be put in command class
342 ** The "maint set python print-stack on|off" is now deleted.
344 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
345 apply "flag enum"-style pretty-printing to any enum.
347 ** gdb.lookup_symbol can now work when there is no current frame.
349 ** gdb.Symbol now has a 'line' attribute, holding the line number in
350 the source at which the symbol was defined.
352 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
353 method 'value'. The former indicates whether the symbol needs a
354 frame in order to compute its value, and the latter computes the
357 ** A new method 'referenced_value' on gdb.Value objects which can
358 dereference pointer as well as C++ reference values.
360 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
361 which return the global and static blocks (as gdb.Block objects),
362 of the underlying symbol table, respectively.
364 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
365 object associated with a PC value.
367 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
368 of the address range occupied by code for the current source line.
370 * Go language support.
371 GDB now supports debugging programs written in the Go programming
374 * GDBserver now supports stdio connections.
375 E.g. (gdb) target remote | ssh myhost gdbserver - hello
377 * The binary "gdbtui" can no longer be built or installed.
378 Use "gdb -tui" instead.
380 * GDB will now print "flag" enums specially. A flag enum is one where
381 all the enumerator values have no bits in common when pairwise
382 "and"ed. When printing a value whose type is a flag enum, GDB will
383 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
384 (gdb) print (enum E) 3
387 * The filename part of a linespec will now match trailing components
388 of a source file name. For example, "break gcc/expr.c:1000" will
389 now set a breakpoint in build/gcc/expr.c, but not
392 * The "info proc" and "generate-core-file" commands will now also
393 work on remote targets connected to GDBserver on Linux.
395 * The command "info catch" has been removed. It has been disabled
398 * The "catch exception" and "catch assert" commands now accept
399 a condition at the end of the command, much like the "break"
400 command does. For instance:
402 (gdb) catch exception Constraint_Error if Barrier = True
404 Previously, it was possible to add a condition to such catchpoints,
405 but it had to be done as a second step, after the catchpoint had been
406 created, using the "condition" command.
408 * The "info static-tracepoint-marker" command will now also work on
409 native Linux targets with in-process agent.
411 * GDB can now set breakpoints on inlined functions.
413 * The .gdb_index section has been updated to include symbols for
414 inlined functions. GDB will ignore older .gdb_index sections by
415 default, which could cause symbol files to be loaded more slowly
416 until their .gdb_index sections can be recreated. The new command
417 "set use-deprecated-index-sections on" will cause GDB to use any older
418 .gdb_index sections it finds. This will restore performance, but the
419 ability to set breakpoints on inlined functions will be lost in symbol
420 files with older .gdb_index sections.
422 The .gdb_index section has also been updated to record more information
423 about each symbol. This speeds up the "info variables", "info functions"
424 and "info types" commands when used with programs having the .gdb_index
425 section, as well as speeding up debugging with shared libraries using
426 the .gdb_index section.
428 * Ada support for GDB/MI Variable Objects has been added.
430 * GDB can now support 'breakpoint always-inserted mode' in 'record'
435 ** New command -info-os is the MI equivalent of "info os".
437 ** Output logs ("set logging" and related) now include MI output.
441 ** "set use-deprecated-index-sections on|off"
442 "show use-deprecated-index-sections on|off"
443 Controls the use of deprecated .gdb_index sections.
445 ** "catch load" and "catch unload" can be used to stop when a shared
446 library is loaded or unloaded, respectively.
448 ** "enable count" can be used to auto-disable a breakpoint after
451 ** "info vtbl" can be used to show the virtual method tables for
452 C++ and Java objects.
454 ** "explore" and its sub commands "explore value" and "explore type"
455 can be used to reccursively explore values and types of
456 expressions. These commands are available only if GDB is
457 configured with '--with-python'.
459 ** "info auto-load" shows status of all kinds of auto-loaded files,
460 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
461 sequences of commands files, "info auto-load python-scripts"
462 shows status of auto-loading Python script files,
463 "info auto-load local-gdbinit" shows status of loading init file
464 (.gdbinit) from current directory and "info auto-load libthread-db" shows
465 status of inferior specific thread debugging shared library loading.
467 ** "info auto-load-scripts", "set auto-load-scripts on|off"
468 and "show auto-load-scripts" commands have been deprecated, use their
469 "info auto-load python-scripts", "set auto-load python-scripts on|off"
470 and "show auto-load python-scripts" counterparts instead.
472 ** "dprintf location,format,args..." creates a dynamic printf, which
473 is basically a breakpoint that does a printf and immediately
474 resumes your program's execution, so it is like a printf that you
475 can insert dynamically at runtime instead of at compiletime.
477 ** "set print symbol"
479 Controls whether GDB attempts to display the symbol, if any,
480 corresponding to addresses it prints. This defaults to "on", but
481 you can set it to "off" to restore GDB's previous behavior.
483 * Deprecated commands
485 ** For the Renesas Super-H architecture, the "regs" command has been
486 deprecated, and "info all-registers" should be used instead.
490 Renesas RL78 rl78-*-elf
491 HP OpenVMS ia64 ia64-hp-openvms*
493 * GDBserver supports evaluation of breakpoint conditions. When
494 support is advertised by GDBserver, GDB may be told to send the
495 breakpoint conditions in bytecode form to GDBserver. GDBserver
496 will only report the breakpoint trigger to GDB when its condition
502 show mips compression
503 Select the compressed ISA encoding used in functions that have no symbol
504 information available. The encoding can be set to either of:
507 and is updated automatically from ELF file flags if available.
509 set breakpoint condition-evaluation
510 show breakpoint condition-evaluation
511 Control whether breakpoint conditions are evaluated by GDB ("host") or by
512 GDBserver ("target"). Default option "auto" chooses the most efficient
514 This option can improve debugger efficiency depending on the speed of the
518 Disable auto-loading globally.
521 Show auto-loading setting of all kinds of auto-loaded files.
523 set auto-load gdb-scripts on|off
524 show auto-load gdb-scripts
525 Control auto-loading of GDB canned sequences of commands files.
527 set auto-load python-scripts on|off
528 show auto-load python-scripts
529 Control auto-loading of Python script files.
531 set auto-load local-gdbinit on|off
532 show auto-load local-gdbinit
533 Control loading of init file (.gdbinit) from current directory.
535 set auto-load libthread-db on|off
536 show auto-load libthread-db
537 Control auto-loading of inferior specific thread debugging shared library.
539 set auto-load scripts-directory <dir1>[:<dir2>...]
540 show auto-load scripts-directory
541 Set a list of directories from which to load auto-loaded scripts.
542 Automatically loaded Python scripts and GDB scripts are located in one
543 of the directories listed by this option.
544 The delimiter (':' above) may differ according to the host platform.
546 set auto-load safe-path <dir1>[:<dir2>...]
547 show auto-load safe-path
548 Set a list of directories from which it is safe to auto-load files.
549 The delimiter (':' above) may differ according to the host platform.
551 set debug auto-load on|off
553 Control display of debugging info for auto-loading the files above.
555 set dprintf-style gdb|call|agent
557 Control the way in which a dynamic printf is performed; "gdb"
558 requests a GDB printf command, while "call" causes dprintf to call a
559 function in the inferior. "agent" requests that the target agent
560 (such as GDBserver) do the printing.
562 set dprintf-function <expr>
563 show dprintf-function
564 set dprintf-channel <expr>
566 Set the function and optional first argument to the call when using
567 the "call" style of dynamic printf.
569 set disconnected-dprintf on|off
570 show disconnected-dprintf
571 Control whether agent-style dynamic printfs continue to be in effect
572 after GDB disconnects.
574 * New configure options
577 Configure default value for the 'set auto-load scripts-directory'
578 setting above. It defaults to '$debugdir:$datadir/auto-load',
579 $debugdir representing global debugging info directories (available
580 via 'show debug-file-directory') and $datadir representing GDB's data
581 directory (available via 'show data-directory').
583 --with-auto-load-safe-path
584 Configure default value for the 'set auto-load safe-path' setting
585 above. It defaults to the --with-auto-load-dir setting.
587 --without-auto-load-safe-path
588 Set 'set auto-load safe-path' to '/', effectively disabling this
593 z0/z1 conditional breakpoints extension
595 The z0/z1 breakpoint insertion packets have been extended to carry
596 a list of conditional expressions over to the remote stub depending on the
597 condition evaluation mode. The use of this extension can be controlled
598 via the "set remote conditional-breakpoints-packet" command.
602 Specify the signals which the remote stub may pass to the debugged
603 program without GDB involvement.
605 * New command line options
607 --init-command=FILE, -ix Like --command, -x but execute it
608 before loading inferior.
609 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
610 execute it before loading inferior.
612 *** Changes in GDB 7.4
614 * GDB now handles ambiguous linespecs more consistently; the existing
615 FILE:LINE support has been expanded to other types of linespecs. A
616 breakpoint will now be set on all matching locations in all
617 inferiors, and locations will be added or removed according to
620 * GDB now allows you to skip uninteresting functions and files when
621 stepping with the "skip function" and "skip file" commands.
623 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
624 and "show remote hardware-watchpoint-length-limit". These allows to
625 set or show the maximum length limit (in bytes) of a remote
626 target hardware watchpoint.
628 This allows e.g. to use "unlimited" hardware watchpoints with the
629 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
630 watchpoints are slower than real hardware watchpoints but are
631 significantly faster than gdb software watchpoints.
635 ** The register_pretty_printer function in module gdb.printing now takes
636 an optional `replace' argument. If True, the new printer replaces any
639 ** The "maint set python print-stack on|off" command has been
640 deprecated and will be deleted in GDB 7.5.
641 A new command: "set python print-stack none|full|message" has
642 replaced it. Additionally, the default for "print-stack" is
643 now "message", which just prints the error message without
646 ** A prompt substitution hook (prompt_hook) is now available to the
649 ** A new Python module, gdb.prompt has been added to the GDB Python
650 modules library. This module provides functionality for
651 escape sequences in prompts (used by set/show
652 extended-prompt). These escape sequences are replaced by their
655 ** Python commands and convenience-functions located in
656 'data-directory'/python/gdb/command and
657 'data-directory'/python/gdb/function are now automatically loaded
660 ** Blocks now provide four new attributes. global_block and
661 static_block will return the global and static blocks
662 respectively. is_static and is_global are boolean attributes
663 that indicate if the block is one of those two types.
665 ** Symbols now provide the "type" attribute, the type of the symbol.
667 ** The "gdb.breakpoint" function has been deprecated in favor of
670 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
671 of a function. This class is based on the "finish" command
672 available in the CLI.
674 ** Type objects for struct and union types now allow access to
675 the fields using standard Python dictionary (mapping) methods.
676 For example, "some_type['myfield']" now works, as does
679 ** A new event "gdb.new_objfile" has been added, triggered by loading a
682 ** A new function, "deep_items" has been added to the gdb.types
683 module in the GDB Python modules library. This function returns
684 an iterator over the fields of a struct or union type. Unlike
685 the standard Python "iteritems" method, it will recursively traverse
686 any anonymous fields.
690 ** "*stopped" events can report several new "reason"s, such as
693 ** Breakpoint changes are now notified using new async records, like
694 "=breakpoint-modified".
696 ** New command -ada-task-info.
698 * libthread-db-search-path now supports two special values: $sdir and $pdir.
699 $sdir specifies the default system locations of shared libraries.
700 $pdir specifies the directory where the libpthread used by the application
703 GDB no longer looks in $sdir and $pdir after it has searched the directories
704 mentioned in libthread-db-search-path. If you want to search those
705 directories, they must be specified in libthread-db-search-path.
706 The default value of libthread-db-search-path on GNU/Linux and Solaris
707 systems is now "$sdir:$pdir".
709 $pdir is not supported by gdbserver, it is currently ignored.
710 $sdir is supported by gdbserver.
712 * New configure option --with-iconv-bin.
713 When using the internationalization support like the one in the GNU C
714 library, GDB will invoke the "iconv" program to get a list of supported
715 character sets. If this program lives in a non-standard location, one can
716 use this option to specify where to find it.
718 * When natively debugging programs on PowerPC BookE processors running
719 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
720 watchpoints, which specify a mask in addition to an address to watch.
721 The mask specifies that some bits of an address (the bits which are
722 reset in the mask) should be ignored when matching the address accessed
723 by the inferior against the watchpoint address. See the "PowerPC Embedded"
724 section in the user manual for more details.
726 * The new option --once causes GDBserver to stop listening for connections once
727 the first connection is made. The listening port used by GDBserver will
728 become available after that.
730 * New commands "info macros" and "alias" have been added.
732 * New function parameters suffix @entry specifies value of function parameter
733 at the time the function got called. Entry values are available only since
739 "!" is now an alias of the "shell" command.
740 Note that no space is needed between "!" and SHELL COMMAND.
744 watch EXPRESSION mask MASK_VALUE
745 The watch command now supports the mask argument which allows creation
746 of masked watchpoints, if the current architecture supports this feature.
748 info auto-load-scripts [REGEXP]
749 This command was formerly named "maintenance print section-scripts".
750 It is now generally useful and is no longer a maintenance-only command.
752 info macro [-all] [--] MACRO
753 The info macro command has new options `-all' and `--'. The first for
754 printing all definitions of a macro. The second for explicitly specifying
755 the end of arguments and the beginning of the macro name in case the macro
756 name starts with a hyphen.
758 collect[/s] EXPRESSIONS
759 The tracepoint collect command now takes an optional modifier "/s"
760 that directs it to dereference pointer-to-character types and
761 collect the bytes of memory up to a zero byte. The behavior is
762 similar to what you see when you use the regular print command on a
763 string. An optional integer following the "/s" sets a bound on the
764 number of bytes that will be collected.
767 The trace start command now interprets any supplied arguments as a
768 note to be recorded with the trace run, with an effect similar to
769 setting the variable trace-notes.
772 The trace stop command now interprets any arguments as a note to be
773 mentioned along with the tstatus report that the trace was stopped
774 with a command. The effect is similar to setting the variable
777 * Tracepoints can now be enabled and disabled at any time after a trace
778 experiment has been started using the standard "enable" and "disable"
779 commands. It is now possible to start a trace experiment with no enabled
780 tracepoints; GDB will display a warning, but will allow the experiment to
781 begin, assuming that tracepoints will be enabled as needed while the trace
784 * Fast tracepoints on 32-bit x86-architectures can now be placed at
785 locations with 4-byte instructions, when they were previously
786 limited to locations with instructions of 5 bytes or longer.
790 set debug dwarf2-read
791 show debug dwarf2-read
792 Turns on or off display of debugging messages related to reading
793 DWARF debug info. The default is off.
795 set debug symtab-create
796 show debug symtab-create
797 Turns on or off display of debugging messages related to symbol table
798 creation. The default is off.
802 Set the GDB prompt, and allow escape sequences to be inserted to
803 display miscellaneous information (see 'help set extended-prompt'
804 for the list of sequences). This prompt (and any information
805 accessed through the escape sequences) is updated every time the
808 set print entry-values (both|compact|default|if-needed|no|only|preferred)
809 show print entry-values
810 Set printing of frame argument values at function entry. In some cases
811 GDB can determine the value of function argument which was passed by the
812 function caller, even if the value was modified inside the called function.
814 set debug entry-values
815 show debug entry-values
816 Control display of debugging info for determining frame argument values at
817 function entry and virtual tail call frames.
819 set basenames-may-differ
820 show basenames-may-differ
821 Set whether a source file may have multiple base names.
822 (A "base name" is the name of a file with the directory part removed.
823 Example: The base name of "/home/user/hello.c" is "hello.c".)
824 If set, GDB will canonicalize file names (e.g., expand symlinks)
825 before comparing them. Canonicalization is an expensive operation,
826 but it allows the same file be known by more than one base name.
827 If not set (the default), all source files are assumed to have just
828 one base name, and gdb will do file name comparisons more efficiently.
834 Set a user name and notes for the current and any future trace runs.
835 This is useful for long-running and/or disconnected traces, to
836 inform others (or yourself) as to who is running the trace, supply
837 contact information, or otherwise explain what is going on.
840 show trace-stop-notes
841 Set a note attached to the trace run, that is displayed when the
842 trace has been stopped by a tstop command. This is useful for
843 instance as an explanation, if you are stopping a trace run that was
844 started by someone else.
850 Dynamically enable a tracepoint in a started trace experiment.
854 Dynamically disable a tracepoint in a started trace experiment.
858 Set the user and notes of the trace run.
862 Query the current status of a tracepoint.
866 Query the minimum length of instruction at which a fast tracepoint may
869 * Dcache size (number of lines) and line-size are now runtime-configurable
870 via "set dcache line" and "set dcache line-size" commands.
874 Texas Instruments TMS320C6x tic6x-*-*
878 Renesas RL78 rl78-*-elf
880 *** Changes in GDB 7.3.1
882 * The build failure for NetBSD and OpenBSD targets have now been fixed.
884 *** Changes in GDB 7.3
886 * GDB has a new command: "thread find [REGEXP]".
887 It finds the thread id whose name, target id, or thread extra info
888 matches the given regular expression.
890 * The "catch syscall" command now works on mips*-linux* targets.
892 * The -data-disassemble MI command now supports modes 2 and 3 for
893 dumping the instruction opcodes.
895 * New command line options
897 -data-directory DIR Specify DIR as the "data-directory".
898 This is mostly for testing purposes.
900 * The "maint set python auto-load on|off" command has been renamed to
901 "set auto-load-scripts on|off".
903 * GDB has a new command: "set directories".
904 It is like the "dir" command except that it replaces the
905 source path list instead of augmenting it.
907 * GDB now understands thread names.
909 On GNU/Linux, "info threads" will display the thread name as set by
910 prctl or pthread_setname_np.
912 There is also a new command, "thread name", which can be used to
913 assign a name internally for GDB to display.
916 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
917 has been integrated into GDB.
921 ** The function gdb.Write now accepts an optional keyword 'stream'.
922 This keyword, when provided, will direct the output to either
923 stdout, stderr, or GDB's logging output.
925 ** Parameters can now be be sub-classed in Python, and in particular
926 you may implement the get_set_doc and get_show_doc functions.
927 This improves how Parameter set/show documentation is processed
928 and allows for more dynamic content.
930 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
931 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
932 have an is_valid method.
934 ** Breakpoints can now be sub-classed in Python, and in particular
935 you may implement a 'stop' function that is executed each time
936 the inferior reaches that breakpoint.
938 ** New function gdb.lookup_global_symbol looks up a global symbol.
940 ** GDB values in Python are now callable if the value represents a
941 function. For example, if 'some_value' represents a function that
942 takes two integer parameters and returns a value, you can call
943 that function like so:
945 result = some_value (10,20)
947 ** Module gdb.types has been added.
948 It contains a collection of utilities for working with gdb.Types objects:
949 get_basic_type, has_field, make_enum_dict.
951 ** Module gdb.printing has been added.
952 It contains utilities for writing and registering pretty-printers.
953 New classes: PrettyPrinter, SubPrettyPrinter,
954 RegexpCollectionPrettyPrinter.
955 New function: register_pretty_printer.
957 ** New commands "info pretty-printers", "enable pretty-printer" and
958 "disable pretty-printer" have been added.
960 ** gdb.parameter("directories") is now available.
962 ** New function gdb.newest_frame returns the newest frame in the
965 ** The gdb.InferiorThread class has a new "name" attribute. This
966 holds the thread's name.
968 ** Python Support for Inferior events.
969 Python scripts can add observers to be notified of events
970 occurring in the process being debugged.
971 The following events are currently supported:
972 - gdb.events.cont Continue event.
973 - gdb.events.exited Inferior exited event.
974 - gdb.events.stop Signal received, and Breakpoint hit events.
978 ** GDB now puts template parameters in scope when debugging in an
979 instantiation. For example, if you have:
981 template<int X> int func (void) { return X; }
983 then if you step into func<5>, "print X" will show "5". This
984 feature requires proper debuginfo support from the compiler; it
985 was added to GCC 4.5.
987 ** The motion commands "next", "finish", "until", and "advance" now
988 work better when exceptions are thrown. In particular, GDB will
989 no longer lose control of the inferior; instead, the GDB will
990 stop the inferior at the point at which the exception is caught.
991 This functionality requires a change in the exception handling
992 code that was introduced in GCC 4.5.
994 * GDB now follows GCC's rules on accessing volatile objects when
995 reading or writing target state during expression evaluation.
996 One notable difference to prior behavior is that "print x = 0"
997 no longer generates a read of x; the value of the assignment is
998 now always taken directly from the value being assigned.
1000 * GDB now has some support for using labels in the program's source in
1001 linespecs. For instance, you can use "advance label" to continue
1002 execution to a label.
1004 * GDB now has support for reading and writing a new .gdb_index
1005 section. This section holds a fast index of DWARF debugging
1006 information and can be used to greatly speed up GDB startup and
1007 operation. See the documentation for `save gdb-index' for details.
1009 * The "watch" command now accepts an optional "-location" argument.
1010 When used, this causes GDB to watch the memory referred to by the
1011 expression. Such a watchpoint is never deleted due to it going out
1014 * GDB now supports thread debugging of core dumps on GNU/Linux.
1016 GDB now activates thread debugging using the libthread_db library
1017 when debugging GNU/Linux core dumps, similarly to when debugging
1018 live processes. As a result, when debugging a core dump file, GDB
1019 is now able to display pthread_t ids of threads. For example, "info
1020 threads" shows the same output as when debugging the process when it
1021 was live. In earlier releases, you'd see something like this:
1024 * 1 LWP 6780 main () at main.c:10
1026 While now you see this:
1029 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1031 It is also now possible to inspect TLS variables when debugging core
1034 When debugging a core dump generated on a machine other than the one
1035 used to run GDB, you may need to point GDB at the correct
1036 libthread_db library with the "set libthread-db-search-path"
1037 command. See the user manual for more details on this command.
1039 * When natively debugging programs on PowerPC BookE processors running
1040 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1041 which stop execution of the inferior whenever it executes an instruction
1042 at any address within the specified range. See the "PowerPC Embedded"
1043 section in the user manual for more details.
1045 * New features in the GDB remote stub, GDBserver
1047 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1048 and i686 LynxOS (version 5.x).
1050 ** GDBserver is now supported on Blackfin Linux.
1052 * New native configurations
1054 ia64 HP-UX ia64-*-hpux*
1058 Analog Devices, Inc. Blackfin Processor bfin-*
1060 * Ada task switching is now supported on sparc-elf targets when
1061 debugging a program using the Ravenscar Profile. For more information,
1062 see the "Tasking Support when using the Ravenscar Profile" section
1063 in the GDB user manual.
1065 * Guile support was removed.
1067 * New features in the GNU simulator
1069 ** The --map-info flag lists all known core mappings.
1071 ** CFI flashes may be simulated via the "cfi" device.
1073 *** Changes in GDB 7.2
1075 * Shared library support for remote targets by default
1077 When GDB is configured for a generic, non-OS specific target, like
1078 for example, --target=arm-eabi or one of the many *-*-elf targets,
1079 GDB now queries remote stubs for loaded shared libraries using the
1080 `qXfer:libraries:read' packet. Previously, shared library support
1081 was always disabled for such configurations.
1085 ** Argument Dependent Lookup (ADL)
1087 In C++ ADL lookup directs function search to the namespaces of its
1088 arguments even if the namespace has not been imported.
1098 Here the compiler will search for `foo' in the namespace of 'b'
1099 and find A::foo. GDB now supports this. This construct is commonly
1100 used in the Standard Template Library for operators.
1102 ** Improved User Defined Operator Support
1104 In addition to member operators, GDB now supports lookup of operators
1105 defined in a namespace and imported with a `using' directive, operators
1106 defined in the global scope, operators imported implicitly from an
1107 anonymous namespace, and the ADL operators mentioned in the previous
1109 GDB now also supports proper overload resolution for all the previously
1110 mentioned flavors of operators.
1112 ** static const class members
1114 Printing of static const class members that are initialized in the
1115 class definition has been fixed.
1117 * Windows Thread Information Block access.
1119 On Windows targets, GDB now supports displaying the Windows Thread
1120 Information Block (TIB) structure. This structure is visible either
1121 by using the new command `info w32 thread-information-block' or, by
1122 dereferencing the new convenience variable named `$_tlb', a
1123 thread-specific pointer to the TIB. This feature is also supported
1124 when remote debugging using GDBserver.
1126 * Static tracepoints
1128 Static tracepoints are calls in the user program into a tracing
1129 library. One such library is a port of the LTTng kernel tracer to
1130 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1131 When debugging with GDBserver, GDB now supports combining the GDB
1132 tracepoint machinery with such libraries. For example: the user can
1133 use GDB to probe a static tracepoint marker (a call from the user
1134 program into the tracing library) with the new "strace" command (see
1135 "New commands" below). This creates a "static tracepoint" in the
1136 breakpoint list, that can be manipulated with the same feature set
1137 as fast and regular tracepoints. E.g., collect registers, local and
1138 global variables, collect trace state variables, and define
1139 tracepoint conditions. In addition, the user can collect extra
1140 static tracepoint marker specific data, by collecting the new
1141 $_sdata internal variable. When analyzing the trace buffer, you can
1142 inspect $_sdata like any other variable available to GDB. For more
1143 information, see the "Tracepoints" chapter in GDB user manual. New
1144 remote packets have been defined to support static tracepoints, see
1145 the "New remote packets" section below.
1147 * Better reconstruction of tracepoints after disconnected tracing
1149 GDB will attempt to download the original source form of tracepoint
1150 definitions when starting a trace run, and then will upload these
1151 upon reconnection to the target, resulting in a more accurate
1152 reconstruction of the tracepoints that are in use on the target.
1156 You can now exercise direct control over the ways that GDB can
1157 affect your program. For instance, you can disallow the setting of
1158 breakpoints, so that the program can run continuously (assuming
1159 non-stop mode). In addition, the "observer" variable is available
1160 to switch all of the different controls; in observer mode, GDB
1161 cannot affect the target's behavior at all, which is useful for
1162 tasks like diagnosing live systems in the field.
1164 * The new convenience variable $_thread holds the number of the
1167 * New remote packets
1171 Return the address of the Windows Thread Information Block of a given thread.
1175 In response to several of the tracepoint packets, the target may now
1176 also respond with a number of intermediate `qRelocInsn' request
1177 packets before the final result packet, to have GDB handle
1178 relocating an instruction to execute at a different address. This
1179 is particularly useful for stubs that support fast tracepoints. GDB
1180 reports support for this feature in the qSupported packet.
1184 List static tracepoint markers in the target program.
1188 List static tracepoint markers at a given address in the target
1191 qXfer:statictrace:read
1193 Read the static trace data collected (by a `collect $_sdata'
1194 tracepoint action). The remote stub reports support for this packet
1195 to gdb's qSupported query.
1199 Send the current settings of GDB's permission flags.
1203 Send part of the source (textual) form of a tracepoint definition,
1204 which includes location, conditional, and action list.
1206 * The source command now accepts a -s option to force searching for the
1207 script in the source search path even if the script name specifies
1210 * New features in the GDB remote stub, GDBserver
1212 - GDBserver now support tracepoints (including fast tracepoints, and
1213 static tracepoints). The feature is currently supported by the
1214 i386-linux and amd64-linux builds. See the "Tracepoints support
1215 in gdbserver" section in the manual for more information.
1217 GDBserver JIT compiles the tracepoint's conditional agent
1218 expression bytecode into native code whenever possible for low
1219 overhead dynamic tracepoints conditionals. For such tracepoints,
1220 an expression that examines program state is evaluated when the
1221 tracepoint is reached, in order to determine whether to capture
1222 trace data. If the condition is simple and false, processing the
1223 tracepoint finishes very quickly and no data is gathered.
1225 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1226 for static tracepoints support.
1228 - GDBserver now supports x86_64 Windows 64-bit debugging.
1230 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1231 it understands register description.
1233 * The --batch flag now disables pagination and queries.
1235 * X86 general purpose registers
1237 GDB now supports reading/writing byte, word and double-word x86
1238 general purpose registers directly. This means you can use, say,
1239 $ah or $ax to refer, respectively, to the byte register AH and
1240 16-bit word register AX that are actually portions of the 32-bit
1241 register EAX or 64-bit register RAX.
1243 * The `commands' command now accepts a range of breakpoints to modify.
1244 A plain `commands' following a command that creates multiple
1245 breakpoints affects all the breakpoints set by that command. This
1246 applies to breakpoints set by `rbreak', and also applies when a
1247 single `break' command creates multiple breakpoints (e.g.,
1248 breakpoints on overloaded c++ functions).
1250 * The `rbreak' command now accepts a filename specification as part of
1251 its argument, limiting the functions selected by the regex to those
1252 in the specified file.
1254 * Support for remote debugging Windows and SymbianOS shared libraries
1255 from Unix hosts has been improved. Non Windows GDB builds now can
1256 understand target reported file names that follow MS-DOS based file
1257 system semantics, such as file names that include drive letters and
1258 use the backslash character as directory separator. This makes it
1259 possible to transparently use the "set sysroot" and "set
1260 solib-search-path" on Unix hosts to point as host copies of the
1261 target's shared libraries. See the new command "set
1262 target-file-system-kind" described below, and the "Commands to
1263 specify files" section in the user manual for more information.
1267 eval template, expressions...
1268 Convert the values of one or more expressions under the control
1269 of the string template to a command line, and call it.
1271 set target-file-system-kind unix|dos-based|auto
1272 show target-file-system-kind
1273 Set or show the assumed file system kind for target reported file
1276 save breakpoints <filename>
1277 Save all current breakpoint definitions to a file suitable for use
1278 in a later debugging session. To read the saved breakpoint
1279 definitions, use the `source' command.
1281 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1284 info static-tracepoint-markers
1285 Display information about static tracepoint markers in the target.
1287 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1288 Define a static tracepoint by probing a marker at the given
1289 function, line, address, or marker ID.
1293 Enable and disable observer mode.
1295 set may-write-registers on|off
1296 set may-write-memory on|off
1297 set may-insert-breakpoints on|off
1298 set may-insert-tracepoints on|off
1299 set may-insert-fast-tracepoints on|off
1300 set may-interrupt on|off
1301 Set individual permissions for GDB effects on the target. Note that
1302 some of these settings can have undesirable or surprising
1303 consequences, particularly when changed in the middle of a session.
1304 For instance, disabling the writing of memory can prevent
1305 breakpoints from being inserted, cause single-stepping to fail, or
1306 even crash your program, if you disable after breakpoints have been
1307 inserted. However, GDB should not crash.
1309 set record memory-query on|off
1310 show record memory-query
1311 Control whether to stop the inferior if memory changes caused
1312 by an instruction cannot be recorded.
1317 The disassemble command now supports "start,+length" form of two arguments.
1321 ** GDB now provides a new directory location, called the python directory,
1322 where Python scripts written for GDB can be installed. The location
1323 of that directory is <data-directory>/python, where <data-directory>
1324 is the GDB data directory. For more details, see section `Scripting
1325 GDB using Python' in the manual.
1327 ** The GDB Python API now has access to breakpoints, symbols, symbol
1328 tables, program spaces, inferiors, threads and frame's code blocks.
1329 Additionally, GDB Parameters can now be created from the API, and
1330 manipulated via set/show in the CLI.
1332 ** New functions gdb.target_charset, gdb.target_wide_charset,
1333 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1335 ** New exception gdb.GdbError.
1337 ** Pretty-printers are now also looked up in the current program space.
1339 ** Pretty-printers can now be individually enabled and disabled.
1341 ** GDB now looks for names of Python scripts to auto-load in a
1342 special section named `.debug_gdb_scripts', in addition to looking
1343 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1345 * Tracepoint actions were unified with breakpoint commands. In particular,
1346 there are no longer differences in "info break" output for breakpoints and
1347 tracepoints and the "commands" command can be used for both tracepoints and
1348 regular breakpoints.
1352 ARM Symbian arm*-*-symbianelf*
1354 * D language support.
1355 GDB now supports debugging programs written in the D programming
1358 * GDB now supports the extended ptrace interface for PowerPC which is
1359 available since Linux kernel version 2.6.34. This automatically enables
1360 any hardware breakpoints and additional hardware watchpoints available in
1361 the processor. The old ptrace interface exposes just one hardware
1362 watchpoint and no hardware breakpoints.
1364 * GDB is now able to use the Data Value Compare (DVC) register available on
1365 embedded PowerPC processors to implement in hardware simple watchpoint
1366 conditions of the form:
1368 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1370 This works in native GDB running on Linux kernels with the extended ptrace
1371 interface mentioned above.
1373 *** Changes in GDB 7.1
1377 ** Namespace Support
1379 GDB now supports importing of namespaces in C++. This enables the
1380 user to inspect variables from imported namespaces. Support for
1381 namepace aliasing has also been added. So, if a namespace is
1382 aliased in the current scope (e.g. namepace C=A; ) the user can
1383 print variables using the alias (e.g. (gdb) print C::x).
1387 All known bugs relating to the printing of virtual base class were
1388 fixed. It is now possible to call overloaded static methods using a
1393 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1394 and reinterpret_cast<> are now handled by the C++ expression parser.
1398 Xilinx MicroBlaze microblaze-*-*
1403 Xilinx MicroBlaze microblaze
1406 * Multi-program debugging.
1408 GDB now has support for multi-program (a.k.a. multi-executable or
1409 multi-exec) debugging. This allows for debugging multiple inferiors
1410 simultaneously each running a different program under the same GDB
1411 session. See "Debugging Multiple Inferiors and Programs" in the
1412 manual for more information. This implied some user visible changes
1413 in the multi-inferior support. For example, "info inferiors" now
1414 lists inferiors that are not running yet or that have exited
1415 already. See also "New commands" and "New options" below.
1417 * New tracing features
1419 GDB's tracepoint facility now includes several new features:
1421 ** Trace state variables
1423 GDB tracepoints now include support for trace state variables, which
1424 are variables managed by the target agent during a tracing
1425 experiment. They are useful for tracepoints that trigger each
1426 other, so for instance one tracepoint can count hits in a variable,
1427 and then a second tracepoint has a condition that is true when the
1428 count reaches a particular value. Trace state variables share the
1429 $-syntax of GDB convenience variables, and can appear in both
1430 tracepoint actions and condition expressions. Use the "tvariable"
1431 command to create, and "info tvariables" to view; see "Trace State
1432 Variables" in the manual for more detail.
1436 GDB now includes an option for defining fast tracepoints, which
1437 targets may implement more efficiently, such as by installing a jump
1438 into the target agent rather than a trap instruction. The resulting
1439 speedup can be by two orders of magnitude or more, although the
1440 tradeoff is that some program locations on some target architectures
1441 might not allow fast tracepoint installation, for instance if the
1442 instruction to be replaced is shorter than the jump. To request a
1443 fast tracepoint, use the "ftrace" command, with syntax identical to
1444 the regular trace command.
1446 ** Disconnected tracing
1448 It is now possible to detach GDB from the target while it is running
1449 a trace experiment, then reconnect later to see how the experiment
1450 is going. In addition, a new variable disconnected-tracing lets you
1451 tell the target agent whether to continue running a trace if the
1452 connection is lost unexpectedly.
1456 GDB now has the ability to save the trace buffer into a file, and
1457 then use that file as a target, similarly to you can do with
1458 corefiles. You can select trace frames, print data that was
1459 collected in them, and use tstatus to display the state of the
1460 tracing run at the moment that it was saved. To create a trace
1461 file, use "tsave <filename>", and to use it, do "target tfile
1464 ** Circular trace buffer
1466 You can ask the target agent to handle the trace buffer as a
1467 circular buffer, discarding the oldest trace frames to make room for
1468 newer ones, by setting circular-trace-buffer to on. This feature may
1469 not be available for all target agents.
1474 The disassemble command, when invoked with two arguments, now requires
1475 the arguments to be comma-separated.
1478 The info variables command now displays variable definitions. Files
1479 which only declare a variable are not shown.
1482 The source command is now capable of sourcing Python scripts.
1483 This feature is dependent on the debugger being build with Python
1486 Related to this enhancement is also the introduction of a new command
1487 "set script-extension" (see below).
1489 * New commands (for set/show, see "New options" below)
1491 record save [<FILENAME>]
1492 Save a file (in core file format) containing the process record
1493 execution log for replay debugging at a later time.
1495 record restore <FILENAME>
1496 Restore the process record execution log that was saved at an
1497 earlier time, for replay debugging.
1499 add-inferior [-copies <N>] [-exec <FILENAME>]
1502 clone-inferior [-copies <N>] [ID]
1503 Make a new inferior ready to execute the same program another
1504 inferior has loaded.
1509 maint info program-spaces
1510 List the program spaces loaded into GDB.
1512 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1513 show remote interrupt-sequence
1514 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1515 as the sequence to the remote target in order to interrupt the execution.
1516 Ctrl-C is a default. Some system prefers BREAK which is high level of
1517 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1518 Magic SysRq g. It is BREAK signal and character 'g'.
1520 set remote interrupt-on-connect [on | off]
1521 show remote interrupt-on-connect
1522 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1523 remote target when gdb connects to it. This is needed when you debug
1526 set remotebreak [on | off]
1528 Deprecated. Use "set/show remote interrupt-sequence" instead.
1530 tvariable $NAME [ = EXP ]
1531 Create or modify a trace state variable.
1534 List trace state variables and their values.
1536 delete tvariable $NAME ...
1537 Delete one or more trace state variables.
1540 Evaluate the given expressions without collecting anything into the
1541 trace buffer. (Valid in tracepoint actions only.)
1543 ftrace FN / FILE:LINE / *ADDR
1544 Define a fast tracepoint at the given function, line, or address.
1546 * New expression syntax
1548 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1549 GDB now parses 0b101010 identically with 42.
1553 set follow-exec-mode new|same
1554 show follow-exec-mode
1555 Control whether GDB reuses the same inferior across an exec call or
1556 creates a new one. This is useful to be able to restart the old
1557 executable after the inferior having done an exec call.
1559 set default-collect EXPR, ...
1560 show default-collect
1561 Define a list of expressions to be collected at each tracepoint.
1562 This is a useful way to ensure essential items are not overlooked,
1563 such as registers or a critical global variable.
1565 set disconnected-tracing
1566 show disconnected-tracing
1567 If set to 1, the target is instructed to continue tracing if it
1568 loses its connection to GDB. If 0, the target is to stop tracing
1571 set circular-trace-buffer
1572 show circular-trace-buffer
1573 If set to on, the target is instructed to use a circular trace buffer
1574 and discard the oldest trace frames instead of stopping the trace due
1575 to a full trace buffer. If set to off, the trace stops when the buffer
1576 fills up. Some targets may not support this.
1578 set script-extension off|soft|strict
1579 show script-extension
1580 If set to "off", the debugger does not perform any script language
1581 recognition, and all sourced files are assumed to be GDB scripts.
1582 If set to "soft" (the default), files are sourced according to
1583 filename extension, falling back to GDB scripts if the first
1585 If set to "strict", files are sourced according to filename extension.
1587 set ada trust-PAD-over-XVS on|off
1588 show ada trust-PAD-over-XVS
1589 If off, activate a workaround against a bug in the debugging information
1590 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1591 the GCC sources for more information about the GNAT encoding and
1592 PAD types in particular). It is always safe to set this option to
1593 off, but this introduces a slight performance penalty. The default
1596 * Python API Improvements
1598 ** GDB provides the new class gdb.LazyString. This is useful in
1599 some pretty-printing cases. The new method gdb.Value.lazy_string
1600 provides a simple way to create objects of this type.
1602 ** The fields returned by gdb.Type.fields now have an
1603 `is_base_class' attribute.
1605 ** The new method gdb.Type.range returns the range of an array type.
1607 ** The new method gdb.parse_and_eval can be used to parse and
1608 evaluate an expression.
1610 * New remote packets
1613 Define a trace state variable.
1616 Get the current value of a trace state variable.
1619 Set desired tracing behavior upon disconnection.
1622 Set the trace buffer to be linear or circular.
1625 Get data about the tracepoints currently in use.
1629 Process record now works correctly with hardware watchpoints.
1631 Multiple bug fixes have been made to the mips-irix port, making it
1632 much more reliable. In particular:
1633 - Debugging threaded applications is now possible again. Previously,
1634 GDB would hang while starting the program, or while waiting for
1635 the program to stop at a breakpoint.
1636 - Attaching to a running process no longer hangs.
1637 - An error occurring while loading a core file has been fixed.
1638 - Changing the value of the PC register now works again. This fixes
1639 problems observed when using the "jump" command, or when calling
1640 a function from GDB, or even when assigning a new value to $pc.
1641 - With the "finish" and "return" commands, the return value for functions
1642 returning a small array is now correctly printed.
1643 - It is now possible to break on shared library code which gets executed
1644 during a shared library init phase (code executed while executing
1645 their .init section). Previously, the breakpoint would have no effect.
1646 - GDB is now able to backtrace through the signal handler for
1647 non-threaded programs.
1649 PIE (Position Independent Executable) programs debugging is now supported.
1650 This includes debugging execution of PIC (Position Independent Code) shared
1651 libraries although for that, it should be possible to run such libraries as an
1654 *** Changes in GDB 7.0
1656 * GDB now has an interface for JIT compilation. Applications that
1657 dynamically generate code can create symbol files in memory and register
1658 them with GDB. For users, the feature should work transparently, and
1659 for JIT developers, the interface is documented in the GDB manual in the
1660 "JIT Compilation Interface" chapter.
1662 * Tracepoints may now be conditional. The syntax is as for
1663 breakpoints; either an "if" clause appended to the "trace" command,
1664 or the "condition" command is available. GDB sends the condition to
1665 the target for evaluation using the same bytecode format as is used
1666 for tracepoint actions.
1668 * The disassemble command now supports: an optional /r modifier, print the
1669 raw instructions in hex as well as in symbolic form, and an optional /m
1670 modifier to print mixed source+assembly.
1672 * Process record and replay
1674 In a architecture environment that supports ``process record and
1675 replay'', ``process record and replay'' target can record a log of
1676 the process execution, and replay it with both forward and reverse
1679 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1680 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1681 set execution-direction {forward|reverse}, for targets that support
1684 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1685 feature is available with a native GDB running on kernel version
1688 * GDB now has support for multi-byte and wide character sets on the
1689 target. Strings whose character type is wchar_t, char16_t, or
1690 char32_t are now correctly printed. GDB supports wide- and unicode-
1691 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1692 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1693 `printf'. This feature requires iconv to work properly; if your
1694 system does not have a working iconv, GDB can use GNU libiconv. See
1695 the installation instructions for more information.
1697 * GDB now supports automatic retrieval of shared library files from
1698 remote targets. To use this feature, specify a system root that begins
1699 with the `remote:' prefix, either via the `set sysroot' command or via
1700 the `--with-sysroot' configure-time option.
1702 * "info sharedlibrary" now takes an optional regex of libraries to show,
1703 and it now reports if a shared library has no debugging information.
1705 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1706 now complete on file names.
1708 * When completing in expressions, gdb will attempt to limit
1709 completions to allowable structure or union fields, where appropriate.
1710 For instance, consider:
1712 # struct example { int f1; double f2; };
1713 # struct example variable;
1716 If the user types TAB at the end of this command line, the available
1717 completions will be "f1" and "f2".
1719 * Inlined functions are now supported. They show up in backtraces, and
1720 the "step", "next", and "finish" commands handle them automatically.
1722 * GDB now supports the token-splicing (##) and stringification (#)
1723 operators when expanding macros. It also supports variable-arity
1726 * GDB now supports inspecting extra signal information, exported by
1727 the new $_siginfo convenience variable. The feature is currently
1728 implemented on linux ARM, i386 and amd64.
1730 * GDB can now display the VFP floating point registers and NEON vector
1731 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1732 can provide these registers (requires Linux 2.6.30 or later). Remote
1733 and simulator targets may also provide them.
1735 * New remote packets
1738 Search memory for a sequence of bytes.
1741 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1742 operation over reliable transport links. Use of this packet is
1743 controlled by the `set remote noack-packet' command.
1746 Kill the process with the specified process ID. Use this in preference
1747 to `k' when multiprocess protocol extensions are supported.
1750 Obtains additional operating system information
1754 Read or write additional signal information.
1756 * Removed remote protocol undocumented extension
1758 An undocumented extension to the remote protocol's `S' stop reply
1759 packet that permited the stub to pass a process id was removed.
1760 Remote servers should use the `T' stop reply packet instead.
1762 * GDB now supports multiple function calling conventions according to the
1763 DWARF-2 DW_AT_calling_convention function attribute.
1765 * The SH target utilizes the aforementioned change to distinguish between gcc
1766 and Renesas calling convention. It also adds the new CLI commands
1767 `set/show sh calling-convention'.
1769 * GDB can now read compressed debug sections, as produced by GNU gold
1770 with the --compress-debug-sections=zlib flag.
1772 * 64-bit core files are now supported on AIX.
1774 * Thread switching is now supported on Tru64.
1776 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1777 which will be allocated using malloc later in program execution.
1779 * The qXfer:libraries:read remote procotol packet now allows passing a
1780 list of section offsets.
1782 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1783 conditions handling signals delivered during attach or thread creation
1784 have also been fixed.
1786 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1787 From the user's standpoint, all unqualified instances of True and False
1788 are treated as the standard definitions, regardless of context.
1790 * GDB now parses C++ symbol and type names more flexibly. For
1793 template<typename T> class C { };
1796 GDB will now correctly handle all of:
1798 ptype C<char const *>
1799 ptype C<char const*>
1800 ptype C<const char *>
1801 ptype C<const char*>
1803 * New features in the GDB remote stub, gdbserver
1805 - The "--wrapper" command-line argument tells gdbserver to use a
1806 wrapper program to launch programs for debugging.
1808 - On PowerPC and S/390 targets, it is now possible to use a single
1809 gdbserver executable to debug both 32-bit and 64-bit programs.
1810 (This requires gdbserver itself to be built as a 64-bit executable.)
1812 - gdbserver uses the new noack protocol mode for TCP connections to
1813 reduce communications latency, if also supported and enabled in GDB.
1815 - Support for the sparc64-linux-gnu target is now included in
1818 - The amd64-linux build of gdbserver now supports debugging both
1819 32-bit and 64-bit programs.
1821 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1822 now support hardware watchpoints, and will use them automatically
1827 GDB now has support for scripting using Python. Whether this is
1828 available is determined at configure time.
1830 New GDB commands can now be written in Python.
1832 * Ada tasking support
1834 Ada tasks can now be inspected in GDB. The following commands have
1838 Print the list of Ada tasks.
1840 Print detailed information about task number N.
1842 Print the task number of the current task.
1844 Switch the context of debugging to task number N.
1846 * Support for user-defined prefixed commands. The "define" command can
1847 add new commands to existing prefixes, e.g. "target".
1849 * Multi-inferior, multi-process debugging.
1851 GDB now has generalized support for multi-inferior debugging. See
1852 "Debugging Multiple Inferiors" in the manual for more information.
1853 Although availability still depends on target support, the command
1854 set is more uniform now. The GNU/Linux specific multi-forks support
1855 has been migrated to this new framework. This implied some user
1856 visible changes; see "New commands" and also "Removed commands"
1859 * Target descriptions can now describe the target OS ABI. See the
1860 "Target Description Format" section in the user manual for more
1863 * Target descriptions can now describe "compatible" architectures
1864 to indicate that the target can execute applications for a different
1865 architecture in addition to those for the main target architecture.
1866 See the "Target Description Format" section in the user manual for
1869 * Multi-architecture debugging.
1871 GDB now includes general supports for debugging applications on
1872 hybrid systems that use more than one single processor architecture
1873 at the same time. Each such hybrid architecture still requires
1874 specific support to be added. The only hybrid architecture supported
1875 in this version of GDB is the Cell Broadband Engine.
1877 * GDB now supports integrated debugging of Cell/B.E. applications that
1878 use both the PPU and SPU architectures. To enable support for hybrid
1879 Cell/B.E. debugging, you need to configure GDB to support both the
1880 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1881 --enable-targets configure option.
1883 * Non-stop mode debugging.
1885 For some targets, GDB now supports an optional mode of operation in
1886 which you can examine stopped threads while other threads continue
1887 to execute freely. This is referred to as non-stop mode, with the
1888 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1889 section in the user manual for more information.
1891 To be able to support remote non-stop debugging, a remote stub needs
1892 to implement the non-stop mode remote protocol extensions, as
1893 described in the "Remote Non-Stop" section of the user manual. The
1894 GDB remote stub, gdbserver, has been adjusted to support these
1895 extensions on linux targets.
1897 * New commands (for set/show, see "New options" below)
1899 catch syscall [NAME(S) | NUMBER(S)]
1900 Catch system calls. Arguments, which should be names of system
1901 calls or their numbers, mean catch only those syscalls. Without
1902 arguments, every syscall will be caught. When the inferior issues
1903 any of the specified syscalls, GDB will stop and announce the system
1904 call, both when it is called and when its call returns. This
1905 feature is currently available with a native GDB running on the
1906 Linux Kernel, under the following architectures: x86, x86_64,
1907 PowerPC and PowerPC64.
1909 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1911 Search memory for a sequence of bytes.
1913 maint set python print-stack
1914 maint show python print-stack
1915 Show a stack trace when an error is encountered in a Python script.
1918 Invoke CODE by passing it to the Python interpreter.
1923 These allow macros to be defined, undefined, and listed
1927 Show operating system information about processes.
1930 List the inferiors currently under GDB's control.
1933 Switch focus to inferior number NUM.
1936 Detach from inferior number NUM.
1939 Kill inferior number NUM.
1943 set spu stop-on-load
1944 show spu stop-on-load
1945 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1947 set spu auto-flush-cache
1948 show spu auto-flush-cache
1949 Control whether to automatically flush the software-managed cache
1950 during Cell/B.E. debugging.
1952 set sh calling-convention
1953 show sh calling-convention
1954 Control the calling convention used when calling SH target functions.
1957 show debug timestamp
1958 Control display of timestamps with GDB debugging output.
1960 set disassemble-next-line
1961 show disassemble-next-line
1962 Control display of disassembled source lines or instructions when
1965 set remote noack-packet
1966 show remote noack-packet
1967 Set/show the use of remote protocol QStartNoAckMode packet. See above
1968 under "New remote packets."
1970 set remote query-attached-packet
1971 show remote query-attached-packet
1972 Control use of remote protocol `qAttached' (query-attached) packet.
1974 set remote read-siginfo-object
1975 show remote read-siginfo-object
1976 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1979 set remote write-siginfo-object
1980 show remote write-siginfo-object
1981 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1984 set remote reverse-continue
1985 show remote reverse-continue
1986 Control use of remote protocol 'bc' (reverse-continue) packet.
1988 set remote reverse-step
1989 show remote reverse-step
1990 Control use of remote protocol 'bs' (reverse-step) packet.
1992 set displaced-stepping
1993 show displaced-stepping
1994 Control displaced stepping mode. Displaced stepping is a way to
1995 single-step over breakpoints without removing them from the debuggee.
1996 Also known as "out-of-line single-stepping".
1999 show debug displaced
2000 Control display of debugging info for displaced stepping.
2002 maint set internal-error
2003 maint show internal-error
2004 Control what GDB does when an internal error is detected.
2006 maint set internal-warning
2007 maint show internal-warning
2008 Control what GDB does when an internal warning is detected.
2013 Use a wrapper program to launch programs for debugging.
2015 set multiple-symbols (all|ask|cancel)
2016 show multiple-symbols
2017 The value of this variable can be changed to adjust the debugger behavior
2018 when an expression or a breakpoint location contains an ambiguous symbol
2019 name (an overloaded function name, for instance).
2021 set breakpoint always-inserted
2022 show breakpoint always-inserted
2023 Keep breakpoints always inserted in the target, as opposed to inserting
2024 them when resuming the target, and removing them when the target stops.
2025 This option can improve debugger performance on slow remote targets.
2027 set arm fallback-mode (arm|thumb|auto)
2028 show arm fallback-mode
2029 set arm force-mode (arm|thumb|auto)
2031 These commands control how ARM GDB determines whether instructions
2032 are ARM or Thumb. The default for both settings is auto, which uses
2033 the current CPSR value for instructions without symbols; previous
2034 versions of GDB behaved as if "set arm fallback-mode arm".
2036 set disable-randomization
2037 show disable-randomization
2038 Standalone programs run with the virtual address space randomization enabled
2039 by default on some platforms. This option keeps the addresses stable across
2040 multiple debugging sessions.
2044 Control whether other threads are stopped or not when some thread hits
2049 Requests that asynchronous execution is enabled in the target, if available.
2050 In this case, it's possible to resume target in the background, and interact
2051 with GDB while the target is running. "show target-async" displays the
2052 current state of asynchronous execution of the target.
2054 set target-wide-charset
2055 show target-wide-charset
2056 The target-wide-charset is the name of the character set that GDB
2057 uses when printing characters whose type is wchar_t.
2059 set tcp auto-retry (on|off)
2061 set tcp connect-timeout
2062 show tcp connect-timeout
2063 These commands allow GDB to retry failed TCP connections to a remote stub
2064 with a specified timeout period; this is useful if the stub is launched
2065 in parallel with GDB but may not be ready to accept connections immediately.
2067 set libthread-db-search-path
2068 show libthread-db-search-path
2069 Control list of directories which GDB will search for appropriate
2072 set schedule-multiple (on|off)
2073 show schedule-multiple
2074 Allow GDB to resume all threads of all processes or only threads of
2075 the current process.
2079 Use more aggressive caching for accesses to the stack. This improves
2080 performance of remote debugging (particularly backtraces) without
2081 affecting correctness.
2083 set interactive-mode (on|off|auto)
2084 show interactive-mode
2085 Control whether GDB runs in interactive mode (on) or not (off).
2086 When in interactive mode, GDB waits for the user to answer all
2087 queries. Otherwise, GDB does not wait and assumes the default
2088 answer. When set to auto (the default), GDB determines which
2089 mode to use based on the stdin settings.
2094 For program forks, this is replaced by the new more generic `info
2095 inferiors' command. To list checkpoints, you can still use the
2096 `info checkpoints' command, which was an alias for the `info forks'
2100 Replaced by the new `inferior' command. To switch between
2101 checkpoints, you can still use the `restart' command, which was an
2102 alias for the `fork' command.
2105 This is removed, since some targets don't have a notion of
2106 processes. To switch between processes, you can still use the
2107 `inferior' command using GDB's own inferior number.
2110 For program forks, this is replaced by the new more generic `kill
2111 inferior' command. To delete a checkpoint, you can still use the
2112 `delete checkpoint' command, which was an alias for the `delete
2116 For program forks, this is replaced by the new more generic `detach
2117 inferior' command. To detach a checkpoint, you can still use the
2118 `detach checkpoint' command, which was an alias for the `detach
2121 * New native configurations
2123 x86/x86_64 Darwin i[34567]86-*-darwin*
2125 x86_64 MinGW x86_64-*-mingw*
2129 Lattice Mico32 lm32-*
2130 x86 DICOS i[34567]86-*-dicos*
2131 x86_64 DICOS x86_64-*-dicos*
2134 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2135 (mingw32ce) debugging.
2141 These commands were actually not implemented on any target.
2143 *** Changes in GDB 6.8
2145 * New native configurations
2147 NetBSD/hppa hppa*-*netbsd*
2148 Xtensa GNU/Linux xtensa*-*-linux*
2152 NetBSD/hppa hppa*-*-netbsd*
2153 Xtensa GNU/Lunux xtensa*-*-linux*
2155 * Change in command line behavior -- corefiles vs. process ids.
2157 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2158 attaching to process NUMBER fails, GDB no longer attempts to open a
2159 core file named NUMBER. Attaching to a program using the -c option
2160 is no longer supported. Instead, use the '-p' or '--pid' options.
2162 * GDB can now be built as a native debugger for debugging Windows x86
2163 (mingw32) Portable Executable (PE) programs.
2165 * Pending breakpoints no longer change their number when their address
2168 * GDB now supports breakpoints with multiple locations,
2169 including breakpoints on C++ constructors, inside C++ templates,
2170 and in inlined functions.
2172 * GDB's ability to debug optimized code has been improved. GDB more
2173 accurately identifies function bodies and lexical blocks that occupy
2174 more than one contiguous range of addresses.
2176 * Target descriptions can now describe registers for PowerPC.
2178 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2179 registers on PowerPC targets.
2181 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2182 targets even when the libthread_db library is not available.
2184 * The GDB remote stub, gdbserver, now supports the new file transfer
2185 commands (remote put, remote get, and remote delete).
2187 * The GDB remote stub, gdbserver, now supports run and attach in
2188 extended-remote mode.
2190 * hppa*64*-*-hpux11* target broken
2191 The debugger is unable to start a program and fails with the following
2192 error: "Error trying to get information about dynamic linker".
2193 The gdb-6.7 release is also affected.
2195 * GDB now supports the --enable-targets= configure option to allow
2196 building a single GDB executable that supports multiple remote
2197 target architectures.
2199 * GDB now supports debugging C and C++ programs which use the
2200 Decimal Floating Point extension. In addition, the PowerPC target
2201 now has a set of pseudo-registers to inspect decimal float values
2202 stored in two consecutive float registers.
2204 * The -break-insert MI command can optionally create pending
2207 * Improved support for debugging Ada
2208 Many improvements to the Ada language support have been made. These
2210 - Better support for Ada2005 interface types
2211 - Improved handling of arrays and slices in general
2212 - Better support for Taft-amendment types
2213 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2215 - Improved command completion in Ada
2218 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2223 set print frame-arguments (all|scalars|none)
2224 show print frame-arguments
2225 The value of this variable can be changed to control which argument
2226 values should be printed by the debugger when displaying a frame.
2231 Transfer files to and from a remote target, and delete remote files.
2238 Transfer files to and from a remote target, and delete remote files.
2240 * New remote packets
2247 Open, close, read, write, and delete files on the remote system.
2250 Attach to an existing process on the remote system, in extended-remote
2254 Run a new process on the remote system, in extended-remote mode.
2256 *** Changes in GDB 6.7
2258 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2259 bfd, libiberty and opcodes, as revealed by static analysis donated by
2260 Coverity, Inc. (http://scan.coverity.com).
2262 * When looking up multiply-defined global symbols, GDB will now prefer the
2263 symbol definition in the current shared library if it was built using the
2264 -Bsymbolic linker option.
2266 * When the Text User Interface (TUI) is not configured, GDB will now
2267 recognize the -tui command-line option and print a message that the TUI
2270 * The GDB remote stub, gdbserver, now has lower overhead for high
2271 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2273 * GDB for MIPS targets now autodetects whether a remote target provides
2274 32-bit or 64-bit register values.
2276 * Support for C++ member pointers has been improved.
2278 * GDB now understands XML target descriptions, which specify the
2279 target's overall architecture. GDB can read a description from
2280 a local file or over the remote serial protocol.
2282 * Vectors of single-byte data use a new integer type which is not
2283 automatically displayed as character or string data.
2285 * The /s format now works with the print command. It displays
2286 arrays of single-byte integers and pointers to single-byte integers
2289 * Target descriptions can now describe target-specific registers,
2290 for architectures which have implemented the support (currently
2291 only ARM, M68K, and MIPS).
2293 * GDB and the GDB remote stub, gdbserver, now support the XScale
2296 * The GDB remote stub, gdbserver, has been updated to support
2297 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2298 has been rewritten to use the standard GDB remote protocol.
2300 * GDB can now step into C++ functions which are called through thunks.
2302 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2304 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2305 layout. It also supports a TextSeg= and DataSeg= response when only
2306 segment base addresses (rather than offsets) are available.
2308 * The /i format now outputs any trailing branch delay slot instructions
2309 immediately following the last instruction within the count specified.
2311 * The GDB remote protocol "T" stop reply packet now supports a
2312 "library" response. Combined with the new "qXfer:libraries:read"
2313 packet, this response allows GDB to debug shared libraries on targets
2314 where the operating system manages the list of loaded libraries (e.g.
2315 Windows and SymbianOS).
2317 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2318 (DLLs) on Windows and Windows CE targets.
2320 * GDB now supports a faster verification that a .debug file matches its binary
2321 according to its build-id signature, if the signature is present.
2327 Enable or disable hardware flow control (RTS/CTS) on the serial port
2328 when debugging using remote targets.
2330 set mem inaccessible-by-default
2331 show mem inaccessible-by-default
2332 If the target supplies a memory map, for instance via the remote
2333 protocol's "qXfer:memory-map:read" packet, setting this variable
2334 prevents GDB from accessing memory outside the memory map. This
2335 is useful for targets with memory mapped registers or which react
2336 badly to accesses of unmapped address space.
2338 set breakpoint auto-hw
2339 show breakpoint auto-hw
2340 If the target supplies a memory map, for instance via the remote
2341 protocol's "qXfer:memory-map:read" packet, setting this variable
2342 lets GDB use hardware breakpoints automatically for memory regions
2343 where it can not use software breakpoints. This covers both the
2344 "break" command and internal breakpoints used for other commands
2345 including "next" and "finish".
2348 catch exception unhandled
2349 Stop the program execution when Ada exceptions are raised.
2352 Stop the program execution when an Ada assertion failed.
2356 Set an alternate system root for target files. This is a more
2357 general version of "set solib-absolute-prefix", which is now
2358 an alias to "set sysroot".
2361 Provide extended SPU facility status information. This set of
2362 commands is available only when debugging the Cell/B.E. SPU
2365 * New native configurations
2367 OpenBSD/sh sh*-*openbsd*
2370 unset tdesc filename
2372 Use the specified local file as an XML target description, and do
2373 not query the target for its built-in description.
2377 OpenBSD/sh sh*-*-openbsd*
2378 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2379 Toshiba Media Processor mep-elf
2381 * New remote packets
2384 Ignore the specified signals; pass them directly to the debugged program
2385 without stopping other threads or reporting them to GDB.
2387 qXfer:features:read:
2388 Read an XML target description from the target, which describes its
2393 Read or write contents of an spufs file on the target system. These
2394 packets are available only on the Cell/B.E. SPU architecture.
2396 qXfer:libraries:read:
2397 Report the loaded shared libraries. Combined with new "T" packet
2398 response, this packet allows GDB to debug shared libraries on
2399 targets where the operating system manages the list of loaded
2400 libraries (e.g. Windows and SymbianOS).
2404 Support for these obsolete configurations has been removed.
2412 i[34567]86-*-lynxos*
2413 i[34567]86-*-netware*
2414 i[34567]86-*-sco3.2v5*
2415 i[34567]86-*-sco3.2v4*
2417 i[34567]86-*-sysv4.2*
2420 i[34567]86-*-unixware2*
2421 i[34567]86-*-unixware*
2430 * Other removed features
2437 Various m68k-only ROM monitors.
2444 Various Renesas ROM monitors and debugging interfaces for SH and
2449 Support for a Macraigor serial interface to on-chip debugging.
2450 GDB does not directly support the newer parallel or USB
2455 A debug information format. The predecessor to DWARF 2 and
2456 DWARF 3, which are still supported.
2458 Support for the HP aCC compiler on HP-UX/PA-RISC
2460 SOM-encapsulated symbolic debugging information, automatic
2461 invocation of pxdb, and the aCC custom C++ ABI. This does not
2462 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2463 with aCC can still be debugged on an assembly level.
2465 MIPS ".pdr" sections
2467 A MIPS-specific format used to describe stack frame layout
2468 in debugging information.
2472 GDB could work with an older version of Guile to debug
2473 the interpreter and Scheme programs running in it.
2475 set mips stack-arg-size
2476 set mips saved-gpreg-size
2478 Use "set mips abi" to control parameter passing for MIPS.
2480 *** Changes in GDB 6.6
2485 Cell Broadband Engine SPU spu-elf
2487 * GDB can now be configured as a cross-debugger targeting native Windows
2488 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2489 running on a Windows system over TCP/IP to debug Windows programs.
2491 * The GDB remote stub, gdbserver, has been updated to support Windows and
2492 Cygwin debugging. Both single-threaded and multi-threaded programs are
2495 * The "set trust-readonly-sections" command works again. This command was
2496 broken in GDB 6.3, 6.4, and 6.5.
2498 * The "load" command now supports writing to flash memory, if the remote
2499 stub provides the required support.
2501 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2502 longer requires symbolic debug information (e.g. DWARF-2).
2507 unset substitute-path
2508 show substitute-path
2509 Manage a list of substitution rules that GDB uses to rewrite the name
2510 of the directories where the sources are located. This can be useful
2511 for instance when the sources were moved to a different location
2512 between compilation and debugging.
2516 Print each CLI command as it is executed. Each command is prefixed with
2517 a number of `+' symbols representing the nesting depth.
2518 The source command now has a `-v' option to enable the same feature.
2522 The ARM Demon monitor support (RDP protocol, "target rdp").
2524 Kernel Object Display, an embedded debugging feature which only worked with
2525 an obsolete version of Cisco IOS.
2527 The 'set download-write-size' and 'show download-write-size' commands.
2529 * New remote packets
2532 Tell a stub about GDB client features, and request remote target features.
2533 The first feature implemented is PacketSize, which allows the target to
2534 specify the size of packets it can handle - to minimize the number of
2535 packets required and improve performance when connected to a remote
2539 Fetch an OS auxilliary vector from the remote stub. This packet is a
2540 more efficient replacement for qPart:auxv:read.
2542 qXfer:memory-map:read:
2543 Fetch a memory map from the remote stub, including information about
2544 RAM, ROM, and flash memory devices.
2549 Erase and program a flash memory device.
2551 * Removed remote packets
2554 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2555 used it, and only gdbserver implemented it.
2557 *** Changes in GDB 6.5
2561 Renesas M32C/M16C m32c-elf
2563 Morpho Technologies ms1 ms1-elf
2567 init-if-undefined Initialize a convenience variable, but
2568 only if it doesn't already have a value.
2570 The following commands are presently only implemented for native GNU/Linux:
2572 checkpoint Save a snapshot of the program state.
2574 restart <n> Return the program state to a
2575 previously saved state.
2577 info checkpoints List currently saved checkpoints.
2579 delete-checkpoint <n> Delete a previously saved checkpoint.
2581 set|show detach-on-fork Tell gdb whether to detach from a newly
2582 forked process, or to keep debugging it.
2584 info forks List forks of the user program that
2585 are available to be debugged.
2587 fork <n> Switch to debugging one of several
2588 forks of the user program that are
2589 available to be debugged.
2591 delete-fork <n> Delete a fork from the list of forks
2592 that are available to be debugged (and
2593 kill the forked process).
2595 detach-fork <n> Delete a fork from the list of forks
2596 that are available to be debugged (and
2597 allow the process to continue).
2601 Morpho Technologies ms2 ms1-elf
2603 * Improved Windows host support
2605 GDB now builds as a cross debugger hosted on i686-mingw32, including
2606 native console support, and remote communications using either
2607 network sockets or serial ports.
2609 * Improved Modula-2 language support
2611 GDB can now print most types in the Modula-2 syntax. This includes:
2612 basic types, set types, record types, enumerated types, range types,
2613 pointer types and ARRAY types. Procedure var parameters are correctly
2614 printed and hexadecimal addresses and character constants are also
2615 written in the Modula-2 syntax. Best results can be obtained by using
2616 GNU Modula-2 together with the -gdwarf-2 command line option.
2620 The ARM rdi-share module.
2622 The Netware NLM debug server.
2624 *** Changes in GDB 6.4
2626 * New native configurations
2628 OpenBSD/arm arm*-*-openbsd*
2629 OpenBSD/mips64 mips64-*-openbsd*
2633 Morpho Technologies ms1 ms1-elf
2635 * New command line options
2637 --batch-silent As for --batch, but totally silent.
2638 --return-child-result The debugger will exist with the same value
2639 the child (debugged) program exited with.
2640 --eval-command COMMAND, -ex COMMAND
2641 Execute a single GDB CLI command. This may be
2642 specified multiple times and in conjunction
2643 with the --command (-x) option.
2645 * Deprecated commands removed
2647 The following commands, that were deprecated in 2000, have been
2651 set|show arm disassembly-flavor set|show arm disassembler
2652 othernames set arm disassembler
2653 set|show remotedebug set|show debug remote
2654 set|show archdebug set|show debug arch
2655 set|show eventdebug set|show debug event
2658 * New BSD user-level threads support
2660 It is now possible to debug programs using the user-level threads
2661 library on OpenBSD and FreeBSD. Currently supported (target)
2664 FreeBSD/amd64 x86_64-*-freebsd*
2665 FreeBSD/i386 i386-*-freebsd*
2666 OpenBSD/i386 i386-*-openbsd*
2668 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2669 are not yet supported.
2671 * New support for Matsushita MN10300 w/sim added
2672 (Work in progress). mn10300-elf.
2674 * REMOVED configurations and files
2676 VxWorks and the XDR protocol *-*-vxworks
2677 Motorola MCORE mcore-*-*
2678 National Semiconductor NS32000 ns32k-*-*
2680 * New "set print array-indexes" command
2682 After turning this setting "on", GDB prints the index of each element
2683 when displaying arrays. The default is "off" to preserve the previous
2686 * VAX floating point support
2688 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2690 * User-defined command support
2692 In addition to using $arg0..$arg9 for argument passing, it is now possible
2693 to use $argc to determine now many arguments have been passed. See the
2694 section on user-defined commands in the user manual for more information.
2696 *** Changes in GDB 6.3:
2698 * New command line option
2700 GDB now accepts -l followed by a number to set the timeout for remote
2703 * GDB works with GCC -feliminate-dwarf2-dups
2705 GDB now supports a more compact representation of DWARF-2 debug
2706 information using DW_FORM_ref_addr references. These are produced
2707 by GCC with the option -feliminate-dwarf2-dups and also by some
2708 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2709 to use -feliminate-dwarf2-dups.
2711 * Internationalization
2713 When supported by the host system, GDB will be built with
2714 internationalization (libintl). The task of marking up the sources is
2715 continued, we're looking forward to our first translation.
2719 Initial support for debugging programs compiled with the GNAT
2720 implementation of the Ada programming language has been integrated
2721 into GDB. In this release, support is limited to expression evaluation.
2723 * New native configurations
2725 GNU/Linux/m32r m32r-*-linux-gnu
2729 GDB's remote protocol now includes support for the 'p' packet. This
2730 packet is used to fetch individual registers from a remote inferior.
2732 * END-OF-LIFE registers[] compatibility module
2734 GDB's internal register infrastructure has been completely rewritten.
2735 The new infrastructure making possible the implementation of key new
2736 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2739 GDB 6.3 will be the last release to include the the registers[]
2740 compatibility module that allowed out-of-date configurations to
2741 continue to work. This change directly impacts the following
2751 powerpc bdm protocol
2753 Unless there is activity to revive these configurations, they will be
2754 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2756 * OBSOLETE configurations and files
2758 Configurations that have been declared obsolete in this release have
2759 been commented out. Unless there is activity to revive these
2760 configurations, the next release of GDB will have their sources
2761 permanently REMOVED.
2770 *** Changes in GDB 6.2.1:
2772 * MIPS `break main; run' gave an heuristic-fence-post warning
2774 When attempting to run even a simple program, a warning about
2775 heuristic-fence-post being hit would be reported. This problem has
2778 * MIPS IRIX 'long double' crashed GDB
2780 When examining a long double variable, GDB would get a segmentation
2781 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2782 IRIX long double values).
2786 A bug in the VAX stack code was causing problems with the "next"
2787 command. This problem has been fixed.
2789 *** Changes in GDB 6.2:
2791 * Fix for ``many threads''
2793 On GNU/Linux systems that use the NPTL threads library, a program
2794 rapidly creating and deleting threads would confuse GDB leading to the
2797 ptrace: No such process.
2798 thread_db_get_info: cannot get thread info: generic error
2800 This problem has been fixed.
2802 * "-async" and "-noasync" options removed.
2804 Support for the broken "-noasync" option has been removed (it caused
2807 * New ``start'' command.
2809 This command runs the program until the begining of the main procedure.
2811 * New BSD Kernel Data Access Library (libkvm) interface
2813 Using ``target kvm'' it is now possible to debug kernel core dumps and
2814 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2815 platforms. Currently supported (native-only) configurations are:
2817 FreeBSD/amd64 x86_64-*-freebsd*
2818 FreeBSD/i386 i?86-*-freebsd*
2819 NetBSD/i386 i?86-*-netbsd*
2820 NetBSD/m68k m68*-*-netbsd*
2821 NetBSD/sparc sparc-*-netbsd*
2822 OpenBSD/amd64 x86_64-*-openbsd*
2823 OpenBSD/i386 i?86-*-openbsd*
2824 OpenBSD/m68k m68*-openbsd*
2825 OpenBSD/sparc sparc-*-openbsd*
2827 * Signal trampoline code overhauled
2829 Many generic problems with GDB's signal handling code have been fixed.
2830 These include: backtraces through non-contiguous stacks; recognition
2831 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2832 call; backtrace through a signal trampoline; step into and out of
2833 signal handlers; and single-stepping in the signal trampoline.
2835 Please note that kernel bugs are a limiting factor here. These
2836 features have been shown to work on an s390 GNU/Linux system that
2837 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2839 * Cygwin support for DWARF 2 added.
2841 * New native configurations
2843 GNU/Linux/hppa hppa*-*-linux*
2844 OpenBSD/hppa hppa*-*-openbsd*
2845 OpenBSD/m68k m68*-*-openbsd*
2846 OpenBSD/m88k m88*-*-openbsd*
2847 OpenBSD/powerpc powerpc-*-openbsd*
2848 NetBSD/vax vax-*-netbsd*
2849 OpenBSD/vax vax-*-openbsd*
2851 * END-OF-LIFE frame compatibility module
2853 GDB's internal frame infrastructure has been completely rewritten.
2854 The new infrastructure making it possible to support key new features
2855 including DWARF 2 Call Frame Information. To aid in the task of
2856 migrating old configurations to this new infrastructure, a
2857 compatibility module, that allowed old configurations to continue to
2858 work, was also included.
2860 GDB 6.2 will be the last release to include this frame compatibility
2861 module. This change directly impacts the following configurations:
2871 Unless there is activity to revive these configurations, they will be
2872 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2874 * REMOVED configurations and files
2876 Sun 3, running SunOS 3 m68*-*-sunos3*
2877 Sun 3, running SunOS 4 m68*-*-sunos4*
2878 Sun 2, running SunOS 3 m68000-*-sunos3*
2879 Sun 2, running SunOS 4 m68000-*-sunos4*
2880 Motorola 680x0 running LynxOS m68*-*-lynxos*
2881 AT&T 3b1/Unix pc m68*-att-*
2882 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2883 decstation mips-dec-* mips-little-*
2884 riscos mips-*-riscos* mips-*-sysv*
2885 sonymips mips-sony-*
2886 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2888 *** Changes in GDB 6.1.1:
2890 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2892 The TUI (Text-mode User Interface) is now built as part of a default
2893 GDB configuration. It is enabled by either selecting the TUI with the
2894 command line option "-i=tui" or by running the separate "gdbtui"
2895 program. For more information on the TUI, see the manual "Debugging
2898 * Pending breakpoint support (also included in GDB 6.1)
2900 Support has been added to allow you to specify breakpoints in shared
2901 libraries that have not yet been loaded. If a breakpoint location
2902 cannot be found, and the "breakpoint pending" option is set to auto,
2903 GDB queries you if you wish to make the breakpoint pending on a future
2904 shared-library load. If and when GDB resolves the breakpoint symbol,
2905 the pending breakpoint is removed as one or more regular breakpoints
2908 Pending breakpoints are very useful for GCJ Java debugging.
2910 * Fixed ISO-C build problems
2912 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2913 non ISO-C code that stopped them being built using a more strict ISO-C
2914 compiler (e.g., IBM's C compiler).
2916 * Fixed build problem on IRIX 5
2918 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2919 wasn't able to compile compile on an IRIX 5 system.
2921 * Added execute permission to gdb/gdbserver/configure
2923 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2924 permission. This bug would cause configure to fail on a number of
2925 systems (Solaris, IRIX). Ref: server/519.
2927 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2929 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2930 has been updated to use constant array sizes.
2932 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2934 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2935 its generated DWARF Call Frame Info. This encoding was causing GDB to
2936 panic, that panic has been fixed. Ref: gdb/1628.
2938 * Fixed a problem when examining parameters in shared library code.
2940 When examining parameters in optimized shared library code generated
2941 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2942 not available''. GDB now correctly displays the variable's value.
2944 *** Changes in GDB 6.1:
2946 * Removed --with-mmalloc
2948 Support for the mmalloc memory manager has been removed, as it
2949 conflicted with the internal gdb byte cache.
2951 * Changes in AMD64 configurations
2953 The AMD64 target now includes the %cs and %ss registers. As a result
2954 the AMD64 remote protocol has changed; this affects the floating-point
2955 and SSE registers. If you rely on those registers for your debugging,
2956 you should upgrade gdbserver on the remote side.
2958 * Revised SPARC target
2960 The SPARC target has been completely revised, incorporating the
2961 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2962 support for LynxOS and SunOS 4 has been dropped. Calling functions
2963 from within GDB on operating systems with a non-executable stack
2964 (Solaris, OpenBSD) now works.
2968 GDB has a new C++ demangler which does a better job on the mangled
2969 names generated by current versions of g++. It also runs faster, so
2970 with this and other changes gdb should now start faster on large C++
2973 * DWARF 2 Location Expressions
2975 GDB support for location expressions has been extended to support function
2976 arguments and frame bases. Older versions of GDB could crash when they
2979 * C++ nested types and namespaces
2981 GDB's support for nested types and namespaces in C++ has been
2982 improved, especially if you use the DWARF 2 debugging format. (This
2983 is the default for recent versions of GCC on most platforms.)
2984 Specifically, if you have a class "Inner" defined within a class or
2985 namespace "Outer", then GDB realizes that the class's name is
2986 "Outer::Inner", not simply "Inner". This should greatly reduce the
2987 frequency of complaints about not finding RTTI symbols. In addition,
2988 if you are stopped at inside of a function defined within a namespace,
2989 GDB modifies its name lookup accordingly.
2991 * New native configurations
2993 NetBSD/amd64 x86_64-*-netbsd*
2994 OpenBSD/amd64 x86_64-*-openbsd*
2995 OpenBSD/alpha alpha*-*-openbsd*
2996 OpenBSD/sparc sparc-*-openbsd*
2997 OpenBSD/sparc64 sparc64-*-openbsd*
2999 * New debugging protocols
3001 M32R with SDI protocol m32r-*-elf*
3003 * "set prompt-escape-char" command deleted.
3005 The command "set prompt-escape-char" has been deleted. This command,
3006 and its very obscure effet on GDB's prompt, was never documented,
3007 tested, nor mentioned in the NEWS file.
3009 * OBSOLETE configurations and files
3011 Configurations that have been declared obsolete in this release have
3012 been commented out. Unless there is activity to revive these
3013 configurations, the next release of GDB will have their sources
3014 permanently REMOVED.
3016 Sun 3, running SunOS 3 m68*-*-sunos3*
3017 Sun 3, running SunOS 4 m68*-*-sunos4*
3018 Sun 2, running SunOS 3 m68000-*-sunos3*
3019 Sun 2, running SunOS 4 m68000-*-sunos4*
3020 Motorola 680x0 running LynxOS m68*-*-lynxos*
3021 AT&T 3b1/Unix pc m68*-att-*
3022 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3023 decstation mips-dec-* mips-little-*
3024 riscos mips-*-riscos* mips-*-sysv*
3025 sonymips mips-sony-*
3026 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3028 * REMOVED configurations and files
3030 SGI Irix-4.x mips-sgi-irix4 or iris4
3031 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3032 Z8000 simulator z8k-zilog-none or z8ksim
3033 Matsushita MN10200 w/simulator mn10200-*-*
3034 H8/500 simulator h8500-hitachi-hms or h8500hms
3035 HP/PA running BSD hppa*-*-bsd*
3036 HP/PA running OSF/1 hppa*-*-osf*
3037 HP/PA Pro target hppa*-*-pro*
3038 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3039 386BSD i[3456]86-*-bsd*
3040 Sequent family i[3456]86-sequent-sysv4*
3041 i[3456]86-sequent-sysv*
3042 i[3456]86-sequent-bsd*
3043 SPARC running LynxOS sparc-*-lynxos*
3044 SPARC running SunOS 4 sparc-*-sunos4*
3045 Tsqware Sparclet sparclet-*-*
3046 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3048 *** Changes in GDB 6.0:
3052 Support for debugging the Objective-C programming language has been
3053 integrated into GDB.
3055 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3057 DWARF 2's Call Frame Information makes available compiler generated
3058 information that more exactly describes the program's run-time stack.
3059 By using this information, GDB is able to provide more robust stack
3062 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3063 have been updated to use a new backtrace mechanism which includes
3064 DWARF 2 CFI support.
3068 GDB's remote protocol has been extended to include support for hosted
3069 file I/O (where the remote target uses GDB's file system). See GDB's
3070 remote protocol documentation for details.
3072 * All targets using the new architecture framework.
3074 All of GDB's targets have been updated to use the new internal
3075 architecture framework. The way is now open for future GDB releases
3076 to include cross-architecture native debugging support (i386 on amd64,
3079 * GNU/Linux's Thread Local Storage (TLS)
3081 GDB now includes support for for the GNU/Linux implementation of
3082 per-thread variables.
3084 * GNU/Linux's Native POSIX Thread Library (NPTL)
3086 GDB's thread code has been updated to work with either the new
3087 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3089 * Separate debug info.
3091 GDB, in conjunction with BINUTILS, now supports a mechanism for
3092 automatically loading debug information from a separate file. Instead
3093 of shipping full debug and non-debug versions of system libraries,
3094 system integrators can now instead ship just the stripped libraries
3095 and optional debug files.
3097 * DWARF 2 Location Expressions
3099 DWARF 2 Location Expressions allow the compiler to more completely
3100 describe the location of variables (even in optimized code) to the
3103 GDB now includes preliminary support for location expressions (support
3104 for DW_OP_piece is still missing).
3108 A number of long standing bugs that caused GDB to die while starting a
3109 Java application have been fixed. GDB's Java support is now
3110 considered "useable".
3112 * GNU/Linux support for fork, vfork, and exec.
3114 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3115 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3118 * GDB supports logging output to a file
3120 There are two new commands, "set logging" and "show logging", which can be
3121 used to capture GDB's output to a file.
3123 * The meaning of "detach" has changed for gdbserver
3125 The "detach" command will now resume the application, as documented. To
3126 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3129 * d10v, m68hc11 `regs' command deprecated
3131 The `info registers' command has been updated so that it displays the
3132 registers using a format identical to the old `regs' command.
3136 A new command, "maint set profile on/off", has been added. This command can
3137 be used to enable or disable profiling while running GDB, to profile a
3138 session or a set of commands. In addition there is a new configure switch,
3139 "--enable-profiling", which will cause GDB to be compiled with profiling
3140 data, for more informative profiling results.
3142 * Default MI syntax changed to "mi2".
3144 The default MI (machine interface) syntax, enabled by the command line
3145 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3146 "mi1", can be enabled by specifying the option "-i=mi1".
3148 Support for the original "mi0" syntax (included in GDB 5.0) has been
3151 Fix for gdb/192: removed extraneous space when displaying frame level.
3152 Fix for gdb/672: update changelist is now output in mi list format.
3153 Fix for gdb/702: a -var-assign that updates the value now shows up
3154 in a subsequent -var-update.
3156 * New native configurations.
3158 FreeBSD/amd64 x86_64-*-freebsd*
3160 * Multi-arched targets.
3162 HP/PA HPUX11 hppa*-*-hpux*
3163 Renesas M32R/D w/simulator m32r-*-elf*
3165 * OBSOLETE configurations and files
3167 Configurations that have been declared obsolete in this release have
3168 been commented out. Unless there is activity to revive these
3169 configurations, the next release of GDB will have their sources
3170 permanently REMOVED.
3172 Z8000 simulator z8k-zilog-none or z8ksim
3173 Matsushita MN10200 w/simulator mn10200-*-*
3174 H8/500 simulator h8500-hitachi-hms or h8500hms
3175 HP/PA running BSD hppa*-*-bsd*
3176 HP/PA running OSF/1 hppa*-*-osf*
3177 HP/PA Pro target hppa*-*-pro*
3178 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3179 Sequent family i[3456]86-sequent-sysv4*
3180 i[3456]86-sequent-sysv*
3181 i[3456]86-sequent-bsd*
3182 Tsqware Sparclet sparclet-*-*
3183 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3185 * REMOVED configurations and files
3188 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3189 IBM AIX PS/2 i[3456]86-*-aix
3190 i386 running Mach 3.0 i[3456]86-*-mach3*
3191 i386 running Mach i[3456]86-*-mach*
3192 i386 running OSF/1 i[3456]86-*osf1mk*
3193 HP/Apollo 68k Family m68*-apollo*-sysv*,
3195 m68*-hp-bsd*, m68*-hp-hpux*
3196 Argonaut Risc Chip (ARC) arc-*-*
3197 Mitsubishi D30V d30v-*-*
3198 Fujitsu FR30 fr30-*-elf*
3199 OS/9000 i[34]86-*-os9k
3200 I960 with MON960 i960-*-coff
3202 * MIPS $fp behavior changed
3204 The convenience variable $fp, for the MIPS, now consistently returns
3205 the address of the current frame's base. Previously, depending on the
3206 context, $fp could refer to either $sp or the current frame's base
3207 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3208 The GNU Source-Level Debugger''.
3210 *** Changes in GDB 5.3:
3212 * GNU/Linux shared library multi-threaded performance improved.
3214 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3215 `/proc', in preference to `ptrace' for memory reads. This may result
3216 in an improvement in the start-up time of multi-threaded, shared
3217 library applications when run under GDB. One GDB user writes: ``loads
3218 shared libs like mad''.
3220 * ``gdbserver'' now supports multi-threaded applications on some targets
3222 Support for debugging multi-threaded applications which use
3223 the GNU/Linux LinuxThreads package has been added for
3224 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3225 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3227 * GDB now supports C/C++ preprocessor macros.
3229 GDB now expands preprocessor macro invocations in C/C++ expressions,
3230 and provides various commands for showing macro definitions and how
3233 The new command `macro expand EXPRESSION' expands any macro
3234 invocations in expression, and shows the result.
3236 The new command `show macro MACRO-NAME' shows the definition of the
3237 macro named MACRO-NAME, and where it was defined.
3239 Most compilers don't include information about macros in the debugging
3240 information by default. In GCC 3.1, for example, you need to compile
3241 your program with the options `-gdwarf-2 -g3'. If the macro
3242 information is present in the executable, GDB will read it.
3244 * Multi-arched targets.
3246 DEC Alpha (partial) alpha*-*-*
3247 DEC VAX (partial) vax-*-*
3249 National Semiconductor NS32000 (partial) ns32k-*-*
3250 Motorola 68000 (partial) m68k-*-*
3251 Motorola MCORE mcore-*-*
3255 Fujitsu FRV architecture added by Red Hat frv*-*-*
3258 * New native configurations
3260 Alpha NetBSD alpha*-*-netbsd*
3261 SH NetBSD sh*-*-netbsdelf*
3262 MIPS NetBSD mips*-*-netbsd*
3263 UltraSPARC NetBSD sparc64-*-netbsd*
3265 * OBSOLETE configurations and files
3267 Configurations that have been declared obsolete in this release have
3268 been commented out. Unless there is activity to revive these
3269 configurations, the next release of GDB will have their sources
3270 permanently REMOVED.
3272 Mitsubishi D30V d30v-*-*
3273 OS/9000 i[34]86-*-os9k
3274 IBM AIX PS/2 i[3456]86-*-aix
3275 Fujitsu FR30 fr30-*-elf*
3276 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3277 Argonaut Risc Chip (ARC) arc-*-*
3278 i386 running Mach 3.0 i[3456]86-*-mach3*
3279 i386 running Mach i[3456]86-*-mach*
3280 i386 running OSF/1 i[3456]86-*osf1mk*
3281 HP/Apollo 68k Family m68*-apollo*-sysv*,
3283 m68*-hp-bsd*, m68*-hp-hpux*
3284 I960 with MON960 i960-*-coff
3286 * OBSOLETE languages
3288 CHILL, a Pascal like language used by telecommunications companies.
3290 * REMOVED configurations and files
3292 AMD 29k family via UDI a29k-amd-udi, udi29k
3293 A29K VxWorks a29k-*-vxworks
3294 AMD 29000 embedded, using EBMON a29k-none-none
3295 AMD 29000 embedded with COFF a29k-none-coff
3296 AMD 29000 embedded with a.out a29k-none-aout
3298 testsuite/gdb.hp/gdb.threads-hp/ directory
3300 * New command "set max-user-call-depth <nnn>"
3302 This command allows the user to limit the call depth of user-defined
3303 commands. The default is 1024.
3305 * Changes in FreeBSD/i386 native debugging.
3307 Support for the "generate-core-file" has been added.
3309 * New commands "dump", "append", and "restore".
3311 These commands allow data to be copied from target memory
3312 to a bfd-format or binary file (dump and append), and back
3313 from a file into memory (restore).
3315 * Improved "next/step" support on multi-processor Alpha Tru64.
3317 The previous single-step mechanism could cause unpredictable problems,
3318 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3319 of a software single-step mechanism prevents this.
3321 *** Changes in GDB 5.2.1:
3329 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3330 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3331 Fix, by Joel Brobecker imported from mainline.
3333 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3334 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3335 Fix, by Fred Fish, imported from mainline.
3337 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3338 Surprisingly enough, it works now.
3339 By Michal Ludvig, imported from mainline.
3341 i386 hardware watchpoint support:
3342 avoid misses on second run for some targets.
3343 By Pierre Muller, imported from mainline.
3345 *** Changes in GDB 5.2:
3347 * New command "set trust-readonly-sections on[off]".
3349 This command is a hint that tells gdb that read-only sections
3350 really are read-only (ie. that their contents will not change).
3351 In this mode, gdb will go to the object file rather than the
3352 target to read memory from read-only sections (such as ".text").
3353 This can be a significant performance improvement on some
3354 (notably embedded) targets.
3356 * New command "generate-core-file" (or "gcore").
3358 This new gdb command allows the user to drop a core file of the child
3359 process state at any time. So far it's been implemented only for
3360 GNU/Linux and Solaris, but should be relatively easily ported to other
3361 hosts. Argument is core file name (defaults to core.<pid>).
3363 * New command line option
3365 GDB now accepts --pid or -p followed by a process id.
3367 * Change in command line behavior -- corefiles vs. process ids.
3369 There is a subtle behavior in the way in which GDB handles
3370 command line arguments. The first non-flag argument is always
3371 a program to debug, but the second non-flag argument may either
3372 be a corefile or a process id. Previously, GDB would attempt to
3373 open the second argument as a corefile, and if that failed, would
3374 issue a superfluous error message and then attempt to attach it as
3375 a process. Now, if the second argument begins with a non-digit,
3376 it will be treated as a corefile. If it begins with a digit,
3377 GDB will attempt to attach it as a process, and if no such process
3378 is found, will then attempt to open it as a corefile.
3380 * Changes in ARM configurations.
3382 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3383 configuration is fully multi-arch.
3385 * New native configurations
3387 ARM NetBSD arm*-*-netbsd*
3388 x86 OpenBSD i[3456]86-*-openbsd*
3389 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3390 Sparc64 running FreeBSD sparc64-*-freebsd*
3394 Sanyo XStormy16 xstormy16-elf
3396 * OBSOLETE configurations and files
3398 Configurations that have been declared obsolete in this release have
3399 been commented out. Unless there is activity to revive these
3400 configurations, the next release of GDB will have their sources
3401 permanently REMOVED.
3403 AMD 29k family via UDI a29k-amd-udi, udi29k
3404 A29K VxWorks a29k-*-vxworks
3405 AMD 29000 embedded, using EBMON a29k-none-none
3406 AMD 29000 embedded with COFF a29k-none-coff
3407 AMD 29000 embedded with a.out a29k-none-aout
3409 testsuite/gdb.hp/gdb.threads-hp/ directory
3411 * REMOVED configurations and files
3413 TI TMS320C80 tic80-*-*
3415 PowerPC Solaris powerpcle-*-solaris*
3416 PowerPC Windows NT powerpcle-*-cygwin32
3417 PowerPC Netware powerpc-*-netware*
3418 Harris/CXUX m88k m88*-harris-cxux*
3419 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3420 ns32k-utek-sysv* ns32k-utek-*
3421 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3422 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3423 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3424 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3425 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3427 * Changes to command line processing
3429 The new `--args' feature can be used to specify command-line arguments
3430 for the inferior from gdb's command line.
3432 * Changes to key bindings
3434 There is a new `operate-and-get-next' function bound to `C-o'.
3436 *** Changes in GDB 5.1.1
3438 Fix compile problem on DJGPP.
3440 Fix a problem with floating-point registers on the i386 being
3443 Fix to stop GDB crashing on .debug_str debug info.
3445 Numerous documentation fixes.
3447 Numerous testsuite fixes.
3449 *** Changes in GDB 5.1:
3451 * New native configurations
3453 Alpha FreeBSD alpha*-*-freebsd*
3454 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3455 MIPS GNU/Linux mips*-*-linux*
3456 MIPS SGI Irix 6.x mips*-sgi-irix6*
3457 ia64 AIX ia64-*-aix*
3458 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3462 Motorola 68HC11 and 68HC12 m68hc11-elf
3464 UltraSparc running GNU/Linux sparc64-*-linux*
3466 * OBSOLETE configurations and files
3468 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3469 Harris/CXUX m88k m88*-harris-cxux*
3470 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3471 ns32k-utek-sysv* ns32k-utek-*
3472 TI TMS320C80 tic80-*-*
3474 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3475 PowerPC Solaris powerpcle-*-solaris*
3476 PowerPC Windows NT powerpcle-*-cygwin32
3477 PowerPC Netware powerpc-*-netware*
3478 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3479 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3480 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3481 Apple Macintosh (MPW) host N/A
3483 stuff.c (Program to stuff files into a specially prepared space in kdb)
3484 kdb-start.c (Main loop for the standalone kernel debugger)
3486 Configurations that have been declared obsolete in this release have
3487 been commented out. Unless there is activity to revive these
3488 configurations, the next release of GDB will have their sources
3489 permanently REMOVED.
3491 * REMOVED configurations and files
3493 Altos 3068 m68*-altos-*
3494 Convex c1-*-*, c2-*-*
3496 ARM RISCix arm-*-* (as host)
3500 * GDB has been converted to ISO C.
3502 GDB's source code has been converted to ISO C. In particular, the
3503 sources are fully protoized, and rely on standard headers being
3508 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3510 * The MI enabled by default.
3512 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3513 revised and enabled by default. Packages which use GDB as a debugging
3514 engine behind a UI or another front end are encouraged to switch to
3515 using the GDB/MI interface, instead of the old annotations interface
3516 which is now deprecated.
3518 * Support for debugging Pascal programs.
3520 GDB now includes support for debugging Pascal programs. The following
3521 main features are supported:
3523 - Pascal-specific data types such as sets;
3525 - automatic recognition of Pascal sources based on file-name
3528 - Pascal-style display of data types, variables, and functions;
3530 - a Pascal expression parser.
3532 However, some important features are not yet supported.
3534 - Pascal string operations are not supported at all;
3536 - there are some problems with boolean types;
3538 - Pascal type hexadecimal constants are not supported
3539 because they conflict with the internal variables format;
3541 - support for Pascal objects and classes is not full yet;
3543 - unlike Pascal, GDB is case-sensitive for symbol names.
3545 * Changes in completion.
3547 Commands such as `shell', `run' and `set args', which pass arguments
3548 to inferior programs, now complete on file names, similar to what
3549 users expect at the shell prompt.
3551 Commands which accept locations, such as `disassemble', `print',
3552 `breakpoint', `until', etc. now complete on filenames as well as
3553 program symbols. Thus, if you type "break foob TAB", and the source
3554 files linked into the programs include `foobar.c', that file name will
3555 be one of the candidates for completion. However, file names are not
3556 considered for completion after you typed a colon that delimits a file
3557 name from a name of a function in that file, as in "break foo.c:bar".
3559 `set demangle-style' completes on available demangling styles.
3561 * New platform-independent commands:
3563 It is now possible to define a post-hook for a command as well as a
3564 hook that runs before the command. For more details, see the
3565 documentation of `hookpost' in the GDB manual.
3567 * Changes in GNU/Linux native debugging.
3569 Support for debugging multi-threaded programs has been completely
3570 revised for all platforms except m68k and sparc. You can now debug as
3571 many threads as your system allows you to have.
3573 Attach/detach is supported for multi-threaded programs.
3575 Support for SSE registers was added for x86. This doesn't work for
3576 multi-threaded programs though.
3578 * Changes in MIPS configurations.
3580 Multi-arch support is enabled for all MIPS configurations.
3582 GDB can now be built as native debugger on SGI Irix 6.x systems for
3583 debugging n32 executables. (Debugging 64-bit executables is not yet
3586 * Unified support for hardware watchpoints in all x86 configurations.
3588 Most (if not all) native x86 configurations support hardware-assisted
3589 breakpoints and watchpoints in a unified manner. This support
3590 implements debug register sharing between watchpoints, which allows to
3591 put a virtually infinite number of watchpoints on the same address,
3592 and also supports watching regions up to 16 bytes with several debug
3595 The new maintenance command `maintenance show-debug-regs' toggles
3596 debugging print-outs in functions that insert, remove, and test
3597 watchpoints and hardware breakpoints.
3599 * Changes in the DJGPP native configuration.
3601 New command ``info dos sysinfo'' displays assorted information about
3602 the CPU, OS, memory, and DPMI server.
3604 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3605 display information about segment descriptors stored in GDT, LDT, and
3608 New commands ``info dos pde'' and ``info dos pte'' display entries
3609 from Page Directory and Page Tables (for now works with CWSDPMI only).
3610 New command ``info dos address-pte'' displays the Page Table entry for
3611 a given linear address.
3613 GDB can now pass command lines longer than 126 characters to the
3614 program being debugged (requires an update to the libdbg.a library
3615 which is part of the DJGPP development kit).
3617 DWARF2 debug info is now supported.
3619 It is now possible to `step' and `next' through calls to `longjmp'.
3621 * Changes in documentation.
3623 All GDB documentation was converted to GFDL, the GNU Free
3624 Documentation License.
3626 Tracepoints-related commands are now fully documented in the GDB
3629 TUI, the Text-mode User Interface, is now documented in the manual.
3631 Tracepoints-related commands are now fully documented in the GDB
3634 The "GDB Internals" manual now has an index. It also includes
3635 documentation of `ui_out' functions, GDB coding standards, x86
3636 hardware watchpoints, and memory region attributes.
3638 * GDB's version number moved to ``version.in''
3640 The Makefile variable VERSION has been replaced by the file
3641 ``version.in''. People creating GDB distributions should update the
3642 contents of this file.
3646 GUD support is now a standard part of the EMACS distribution.
3648 *** Changes in GDB 5.0:
3650 * Improved support for debugging FP programs on x86 targets
3652 Unified and much-improved support for debugging floating-point
3653 programs on all x86 targets. In particular, ``info float'' now
3654 displays the FP registers in the same format on all x86 targets, with
3655 greater level of detail.
3657 * Improvements and bugfixes in hardware-assisted watchpoints
3659 It is now possible to watch array elements, struct members, and
3660 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3661 on x86 targets no longer erroneously trigger when the address is
3664 * Improvements in the native DJGPP version of GDB
3666 The distribution now includes all the scripts and auxiliary files
3667 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3668 machines ``out of the box''.
3670 The DJGPP version can now debug programs that use signals. It is
3671 possible to catch signals that happened in the debuggee, deliver
3672 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3673 would kill the program being debugged.) Programs that hook hardware
3674 interrupts (keyboard, timer, etc.) can also be debugged.
3676 It is now possible to debug DJGPP programs that redirect their
3677 standard handles or switch them to raw (as opposed to cooked) mode, or
3678 even close them. The command ``run < foo > bar'' works as expected,
3679 and ``info terminal'' reports useful information about the debuggee's
3680 terminal, including raw/cooked mode, redirection, etc.
3682 The DJGPP version now uses termios functions for console I/O, which
3683 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3686 DOS-style file names with drive letters are now fully supported by
3689 It is now possible to debug DJGPP programs that switch their working
3690 directory. It is also possible to rerun the debuggee any number of
3691 times without restarting GDB; thus, you can use the same setup,
3692 breakpoints, etc. for many debugging sessions.
3694 * New native configurations
3696 ARM GNU/Linux arm*-*-linux*
3697 PowerPC GNU/Linux powerpc-*-linux*
3701 Motorola MCore mcore-*-*
3702 x86 VxWorks i[3456]86-*-vxworks*
3703 PowerPC VxWorks powerpc-*-vxworks*
3704 TI TMS320C80 tic80-*-*
3706 * OBSOLETE configurations
3708 Altos 3068 m68*-altos-*
3709 Convex c1-*-*, c2-*-*
3711 ARM RISCix arm-*-* (as host)
3714 Configurations that have been declared obsolete will be commented out,
3715 but the code will be left in place. If there is no activity to revive
3716 these configurations before the next release of GDB, the sources will
3717 be permanently REMOVED.
3719 * Gould support removed
3721 Support for the Gould PowerNode and NP1 has been removed.
3723 * New features for SVR4
3725 On SVR4 native platforms (such as Solaris), if you attach to a process
3726 without first loading a symbol file, GDB will now attempt to locate and
3727 load symbols from the running process's executable file.
3729 * Many C++ enhancements
3731 C++ support has been greatly improved. Overload resolution now works properly
3732 in almost all cases. RTTI support is on the way.
3734 * Remote targets can connect to a sub-program
3736 A popen(3) style serial-device has been added. This device starts a
3737 sub-process (such as a stand-alone simulator) and then communicates
3738 with that. The sub-program to run is specified using the syntax
3739 ``|<program> <args>'' vis:
3741 (gdb) set remotedebug 1
3742 (gdb) target extended-remote |mn10300-elf-sim program-args
3744 * MIPS 64 remote protocol
3746 A long standing bug in the mips64 remote protocol where by GDB
3747 expected certain 32 bit registers (ex SR) to be transfered as 32
3748 instead of 64 bits has been fixed.
3750 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3751 added to provide backward compatibility with older versions of GDB.
3753 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3755 The command ``set remotebinarydownload'' command has been replaced by
3756 ``set remote X-packet''. Other commands in ``set remote'' family
3757 include ``set remote P-packet''.
3759 * Breakpoint commands accept ranges.
3761 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3762 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3763 ``tracepoint passcount'' also accepts a range of tracepoints.
3765 * ``apropos'' command added.
3767 The ``apropos'' command searches through command names and
3768 documentation strings, printing out matches, making it much easier to
3769 try to find a command that does what you are looking for.
3773 A new machine oriented interface (MI) has been added to GDB. This
3774 interface is designed for debug environments running GDB as a separate
3775 process. This is part of the long term libGDB project. See the
3776 "GDB/MI" chapter of the GDB manual for further information. It can be
3777 enabled by configuring with:
3779 .../configure --enable-gdbmi
3781 *** Changes in GDB-4.18:
3783 * New native configurations
3785 HP-UX 10.20 hppa*-*-hpux10.20
3786 HP-UX 11.x hppa*-*-hpux11.0*
3787 M68K GNU/Linux m68*-*-linux*
3791 Fujitsu FR30 fr30-*-elf*
3792 Intel StrongARM strongarm-*-*
3793 Mitsubishi D30V d30v-*-*
3795 * OBSOLETE configurations
3797 Gould PowerNode, NP1 np1-*-*, pn-*-*
3799 Configurations that have been declared obsolete will be commented out,
3800 but the code will be left in place. If there is no activity to revive
3801 these configurations before the next release of GDB, the sources will
3802 be permanently REMOVED.
3806 As a compatibility experiment, GDB's source files buildsym.h and
3807 buildsym.c have been converted to pure standard C, no longer
3808 containing any K&R compatibility code. We believe that all systems in
3809 use today either come with a standard C compiler, or have a GCC port
3810 available. If this is not true, please report the affected
3811 configuration to bug-gdb@gnu.org immediately. See the README file for
3812 information about getting a standard C compiler if you don't have one
3817 GDB now uses readline 2.2.
3819 * set extension-language
3821 You can now control the mapping between filename extensions and source
3822 languages by using the `set extension-language' command. For instance,
3823 you can ask GDB to treat .c files as C++ by saying
3824 set extension-language .c c++
3825 The command `info extensions' lists all of the recognized extensions
3826 and their associated languages.
3828 * Setting processor type for PowerPC and RS/6000
3830 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3831 you can use the `set processor' command to specify what variant of the
3832 PowerPC family you are debugging. The command
3836 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3837 following PowerPC and RS6000 variants:
3839 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3840 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3842 403GC IBM PowerPC 403GC
3843 505 Motorola PowerPC 505
3844 860 Motorola PowerPC 860 or 850
3845 601 Motorola PowerPC 601
3846 602 Motorola PowerPC 602
3847 603 Motorola/IBM PowerPC 603 or 603e
3848 604 Motorola PowerPC 604 or 604e
3849 750 Motorola/IBM PowerPC 750 or 750
3851 At the moment, this command just tells GDB what to name the
3852 special-purpose processor registers. Since almost all the affected
3853 registers are inaccessible to user-level programs, this command is
3854 only useful for remote debugging in its present form.
3858 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3859 more extensive support for HP-UX. Added features include shared
3860 library support, kernel threads and hardware watchpoints for 11.00,
3861 support for HP's ANSI C and C++ compilers, and a compatibility mode
3862 for xdb and dbx commands.
3866 HP's donation includes the new concept of catchpoints, which is a
3867 generalization of the old catch command. On HP-UX, it is now possible
3868 to catch exec, fork, and vfork, as well as library loading.
3870 This means that the existing catch command has changed; its first
3871 argument now specifies the type of catch to be set up. See the
3872 output of "help catch" for a list of catchpoint types.
3874 * Debugging across forks
3876 On HP-UX, you can choose which process to debug when a fork() happens
3881 HP has donated a curses-based terminal user interface (TUI). To get
3882 it, build with --enable-tui. Although this can be enabled for any
3883 configuration, at present it only works for native HP debugging.
3885 * GDB remote protocol additions
3887 A new protocol packet 'X' that writes binary data is now available.
3888 Default behavior is to try 'X', then drop back to 'M' if the stub
3889 fails to respond. The settable variable `remotebinarydownload'
3890 allows explicit control over the use of 'X'.
3892 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3893 full 64-bit address. The command
3895 set remoteaddresssize 32
3897 can be used to revert to the old behaviour. For existing remote stubs
3898 the change should not be noticed, as the additional address information
3901 In order to assist in debugging stubs, you may use the maintenance
3902 command `packet' to send any text string to the stub. For instance,
3904 maint packet heythere
3906 sends the packet "$heythere#<checksum>". Note that it is very easy to
3907 disrupt a debugging session by sending the wrong packet at the wrong
3910 The compare-sections command allows you to compare section data on the
3911 target to what is in the executable file without uploading or
3912 downloading, by comparing CRC checksums.
3914 * Tracing can collect general expressions
3916 You may now collect general expressions at tracepoints. This requires
3917 further additions to the target-side stub; see tracepoint.c and
3918 doc/agentexpr.texi for further details.
3920 * mask-address variable for Mips
3922 For Mips targets, you may control the zeroing of the upper 32 bits of
3923 a 64-bit address by entering `set mask-address on'. This is mainly
3924 of interest to users of embedded R4xxx and R5xxx processors.
3926 * Higher serial baud rates
3928 GDB's serial code now allows you to specify baud rates 57600, 115200,
3929 230400, and 460800 baud. (Note that your host system may not be able
3930 to achieve all of these rates.)
3934 The i960 configuration now includes an initial implementation of a
3935 builtin simulator, contributed by Jim Wilson.
3938 *** Changes in GDB-4.17:
3940 * New native configurations
3942 Alpha GNU/Linux alpha*-*-linux*
3943 Unixware 2.x i[3456]86-unixware2*
3944 Irix 6.x mips*-sgi-irix6*
3945 PowerPC GNU/Linux powerpc-*-linux*
3946 PowerPC Solaris powerpcle-*-solaris*
3947 Sparc GNU/Linux sparc-*-linux*
3948 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3952 Argonaut Risc Chip (ARC) arc-*-*
3953 Hitachi H8/300S h8300*-*-*
3954 Matsushita MN10200 w/simulator mn10200-*-*
3955 Matsushita MN10300 w/simulator mn10300-*-*
3956 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3957 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3958 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3959 Mitsubishi D10V w/simulator d10v-*-*
3960 Mitsubishi M32R/D w/simulator m32r-*-elf*
3961 Tsqware Sparclet sparclet-*-*
3962 NEC V850 w/simulator v850-*-*
3964 * New debugging protocols
3966 ARM with RDI protocol arm*-*-*
3967 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3968 DDB and LSI variants of PMON protocol mips*-*-*
3969 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3970 PowerPC with SDS protocol powerpc{,le}-*-eabi
3971 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3975 All configurations can now understand and use the DWARF 2 debugging
3976 format. The choice is automatic, if the symbol file contains DWARF 2
3981 GDB now includes basic Java language support. This support is
3982 only useful with Java compilers that produce native machine code.
3984 * solib-absolute-prefix and solib-search-path
3986 For SunOS and SVR4 shared libraries, you may now set the prefix for
3987 loading absolute shared library symbol files, and the search path for
3988 locating non-absolute shared library symbol files.
3990 * Live range splitting
3992 GDB can now effectively debug code for which GCC has performed live
3993 range splitting as part of its optimization. See gdb/doc/LRS for
3994 more details on the expected format of the stabs information.
3998 GDB's support for the GNU Hurd, including thread debugging, has been
3999 updated to work with current versions of the Hurd.
4003 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4004 instruction set. ARM GDB automatically detects when Thumb
4005 instructions are in use, and adjusts disassembly and backtracing
4010 GDB's MIPS target configurations now handle the MIP16 16-bit
4015 GDB now includes support for overlays; if an executable has been
4016 linked such that multiple sections are based at the same address, GDB
4017 will decide which section to use for symbolic info. You can choose to
4018 control the decision manually, using overlay commands, or implement
4019 additional target-side support and use "overlay load-target" to bring
4020 in the overlay mapping. Do "help overlay" for more detail.
4024 The command "info symbol <address>" displays information about
4025 the symbol at the specified address.
4029 The standard remote protocol now includes an extension that allows
4030 asynchronous collection and display of trace data. This requires
4031 extensive support in the target-side debugging stub. Tracing mode
4032 includes a new interaction mode in GDB and new commands: see the
4033 file tracepoint.c for more details.
4037 Configurations for embedded MIPS now include a simulator contributed
4038 by Cygnus Solutions. The simulator supports the instruction sets
4039 of most MIPS variants.
4043 Sparc configurations may now include the ERC32 simulator contributed
4044 by the European Space Agency. The simulator is not built into
4045 Sparc targets by default; configure with --enable-sim to include it.
4049 For target configurations that may include multiple variants of a
4050 basic architecture (such as MIPS and SH), you may now set the
4051 architecture explicitly. "set arch" sets, "info arch" lists
4052 the possible architectures.
4054 *** Changes in GDB-4.16:
4056 * New native configurations
4058 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4059 M68K NetBSD m68k-*-netbsd*
4060 PowerPC AIX 4.x powerpc-*-aix*
4061 PowerPC MacOS powerpc-*-macos*
4062 PowerPC Windows NT powerpcle-*-cygwin32
4063 RS/6000 AIX 4.x rs6000-*-aix4*
4067 ARM with RDP protocol arm-*-*
4068 I960 with MON960 i960-*-coff
4069 MIPS VxWorks mips*-*-vxworks*
4070 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4071 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4073 Matra Sparclet sparclet-*-*
4077 The powerpc-eabi configuration now includes the PSIM simulator,
4078 contributed by Andrew Cagney, with assistance from Mike Meissner.
4079 PSIM is a very elaborate model of the PowerPC, including not only
4080 basic instruction set execution, but also details of execution unit
4081 performance and I/O hardware. See sim/ppc/README for more details.
4085 GDB now works with Solaris 2.5.
4087 * Windows 95/NT native
4089 GDB will now work as a native debugger on Windows 95 and Windows NT.
4090 To build it from source, you must use the "gnu-win32" environment,
4091 which uses a DLL to emulate enough of Unix to run the GNU tools.
4092 Further information, binaries, and sources are available at
4093 ftp.cygnus.com, under pub/gnu-win32.
4095 * dont-repeat command
4097 If a user-defined command includes the command `dont-repeat', then the
4098 command will not be repeated if the user just types return. This is
4099 useful if the command is time-consuming to run, so that accidental
4100 extra keystrokes don't run the same command many times.
4102 * Send break instead of ^C
4104 The standard remote protocol now includes an option to send a break
4105 rather than a ^C to the target in order to interrupt it. By default,
4106 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4108 * Remote protocol timeout
4110 The standard remote protocol includes a new variable `remotetimeout'
4111 that allows you to set the number of seconds before GDB gives up trying
4112 to read from the target. The default value is 2.
4114 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4116 By default GDB will automatically keep track of objects as they are
4117 loaded and unloaded by the dynamic linker. By using the command `set
4118 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4119 when shared library events occur, thus allowing you to set breakpoints
4120 in shared libraries which are explicitly loaded by the inferior.
4122 Note this feature does not work on hpux8. On hpux9 you must link
4123 /usr/lib/end.o into your program. This feature should work
4124 automatically on hpux10.
4126 * Irix 5.x hardware watchpoint support
4128 Irix 5 configurations now support the use of hardware watchpoints.
4130 * Mips protocol "SYN garbage limit"
4132 When debugging a Mips target using the `target mips' protocol, you
4133 may set the number of characters that GDB will ignore by setting
4134 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4135 every character. The default value is 1050.
4137 * Recording and replaying remote debug sessions
4139 If you set `remotelogfile' to the name of a file, gdb will write to it
4140 a recording of a remote debug session. This recording may then be
4141 replayed back to gdb using "gdbreplay". See gdbserver/README for
4142 details. This is useful when you have a problem with GDB while doing
4143 remote debugging; you can make a recording of the session and send it
4144 to someone else, who can then recreate the problem.
4146 * Speedups for remote debugging
4148 GDB includes speedups for downloading and stepping MIPS systems using
4149 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4150 and more efficient S-record downloading.
4152 * Memory use reductions and statistics collection
4154 GDB now uses less memory and reports statistics about memory usage.
4155 Try the `maint print statistics' command, for example.
4157 *** Changes in GDB-4.15:
4159 * Psymtabs for XCOFF
4161 The symbol reader for AIX GDB now uses partial symbol tables. This
4162 can greatly improve startup time, especially for large executables.
4164 * Remote targets use caching
4166 Remote targets now use a data cache to speed up communication with the
4167 remote side. The data cache could lead to incorrect results because
4168 it doesn't know about volatile variables, thus making it impossible to
4169 debug targets which use memory mapped I/O devices. `set remotecache
4170 off' turns the the data cache off.
4172 * Remote targets may have threads
4174 The standard remote protocol now includes support for multiple threads
4175 in the target system, using new protocol commands 'H' and 'T'. See
4176 gdb/remote.c for details.
4180 If GDB is configured with `--enable-netrom', then it will include
4181 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4182 acts as though it is a bank of ROM on the target board, but you can
4183 write into it over the network. GDB's support consists only of
4184 support for fast loading into the emulated ROM; to debug, you must use
4185 another protocol, such as standard remote protocol. The usual
4186 sequence is something like
4188 target nrom <netrom-hostname>
4190 target remote <netrom-hostname>:1235
4194 GDB now includes support for the Apple Macintosh, as a host only. It
4195 may be run as either an MPW tool or as a standalone application, and
4196 it can debug through the serial port. All the usual GDB commands are
4197 available, but to the target command, you must supply "serial" as the
4198 device type instead of "/dev/ttyXX". See mpw-README in the main
4199 directory for more information on how to build. The MPW configuration
4200 scripts */mpw-config.in support only a few targets, and only the
4201 mips-idt-ecoff target has been tested.
4205 GDB configuration now uses autoconf. This is not user-visible,
4206 but does simplify configuration and building.
4210 GDB now supports hpux10.
4212 *** Changes in GDB-4.14:
4214 * New native configurations
4216 x86 FreeBSD i[345]86-*-freebsd
4217 x86 NetBSD i[345]86-*-netbsd
4218 NS32k NetBSD ns32k-*-netbsd
4219 Sparc NetBSD sparc-*-netbsd
4223 A29K VxWorks a29k-*-vxworks
4224 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4225 CPU32 EST-300 emulator m68*-*-est*
4226 PowerPC ELF powerpc-*-elf
4229 * Alpha OSF/1 support for procfs
4231 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4232 possible to attach to running processes. As the mounting of the /proc
4233 filesystem is optional on the Alpha, GDB automatically determines
4234 the availability of /proc during startup. This can lead to problems
4235 if /proc is unmounted after GDB has been started.
4237 * Arguments to user-defined commands
4239 User commands may accept up to 10 arguments separated by whitespace.
4240 Arguments are accessed within the user command via $arg0..$arg9. A
4243 print $arg0 + $arg1 + $arg2
4245 To execute the command use:
4248 Defines the command "adder" which prints the sum of its three arguments.
4249 Note the arguments are text substitutions, so they may reference variables,
4250 use complex expressions, or even perform inferior function calls.
4252 * New `if' and `while' commands
4254 This makes it possible to write more sophisticated user-defined
4255 commands. Both commands take a single argument, which is the
4256 expression to evaluate, and must be followed by the commands to
4257 execute, one per line, if the expression is nonzero, the list being
4258 terminated by the word `end'. The `if' command list may include an
4259 `else' word, which causes the following commands to be executed only
4260 if the expression is zero.
4262 * Fortran source language mode
4264 GDB now includes partial support for Fortran 77. It will recognize
4265 Fortran programs and can evaluate a subset of Fortran expressions, but
4266 variables and functions may not be handled correctly. GDB will work
4267 with G77, but does not yet know much about symbols emitted by other
4270 * Better HPUX support
4272 Most debugging facilities now work on dynamic executables for HPPAs
4273 running hpux9 or later. You can attach to running dynamically linked
4274 processes, but by default the dynamic libraries will be read-only, so
4275 for instance you won't be able to put breakpoints in them. To change
4276 that behavior do the following before running the program:
4282 This will cause the libraries to be mapped private and read-write.
4283 To revert to the normal behavior, do this:
4289 You cannot set breakpoints or examine data in the library until after
4290 the library is loaded if the function/data symbols do not have
4293 GDB can now also read debug symbols produced by the HP C compiler on
4294 HPPAs (sorry, no C++, Fortran or 68k support).
4296 * Target byte order now dynamically selectable
4298 You can choose which byte order to use with a target system, via the
4299 commands "set endian big" and "set endian little", and you can see the
4300 current setting by using "show endian". You can also give the command
4301 "set endian auto", in which case GDB will use the byte order
4302 associated with the executable. Currently, only embedded MIPS
4303 configurations support dynamic selection of target byte order.
4305 * New DOS host serial code
4307 This version uses DPMI interrupts to handle buffered I/O, so you
4308 no longer need to run asynctsr when debugging boards connected to
4311 *** Changes in GDB-4.13:
4313 * New "complete" command
4315 This lists all the possible completions for the rest of the line, if it
4316 were to be given as a command itself. This is intended for use by emacs.
4318 * Trailing space optional in prompt
4320 "set prompt" no longer adds a space for you after the prompt you set. This
4321 allows you to set a prompt which ends in a space or one that does not.
4323 * Breakpoint hit counts
4325 "info break" now displays a count of the number of times the breakpoint
4326 has been hit. This is especially useful in conjunction with "ignore"; you
4327 can ignore a large number of breakpoint hits, look at the breakpoint info
4328 to see how many times the breakpoint was hit, then run again, ignoring one
4329 less than that number, and this will get you quickly to the last hit of
4332 * Ability to stop printing at NULL character
4334 "set print null-stop" will cause GDB to stop printing the characters of
4335 an array when the first NULL is encountered. This is useful when large
4336 arrays actually contain only short strings.
4338 * Shared library breakpoints
4340 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4341 breakpoints in shared libraries before the executable is run.
4343 * Hardware watchpoints
4345 There is a new hardware breakpoint for the watch command for sparclite
4346 targets. See gdb/sparclite/hw_breakpoint.note.
4348 Hardware watchpoints are also now supported under GNU/Linux.
4352 Annotations have been added. These are for use with graphical interfaces,
4353 and are still experimental. Currently only gdba.el uses these.
4355 * Improved Irix 5 support
4357 GDB now works properly with Irix 5.2.
4359 * Improved HPPA support
4361 GDB now works properly with the latest GCC and GAS.
4363 * New native configurations
4365 Sequent PTX4 i[34]86-sequent-ptx4
4366 HPPA running OSF/1 hppa*-*-osf*
4367 Atari TT running SVR4 m68*-*-sysv4*
4368 RS/6000 LynxOS rs6000-*-lynxos*
4372 OS/9000 i[34]86-*-os9k
4373 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4376 * Hitachi SH7000 and E7000-PC ICE support
4378 There is now support for communicating with the Hitachi E7000-PC ICE.
4379 This is available automatically when GDB is configured for the SH.
4383 As usual, a variety of small fixes and improvements, both generic
4384 and configuration-specific. See the ChangeLog for more detail.
4386 *** Changes in GDB-4.12:
4388 * Irix 5 is now supported
4392 GDB-4.12 on the HPPA has a number of changes which make it unable
4393 to debug the output from the currently released versions of GCC and
4394 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4395 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4396 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4399 *** Changes in GDB-4.11:
4401 * User visible changes:
4405 The "set remotedebug" option is now consistent between the mips remote
4406 target, remote targets using the gdb-specific protocol, UDI (AMD's
4407 debug protocol for the 29k) and the 88k bug monitor. It is now an
4408 integer specifying a debug level (normally 0 or 1, but 2 means more
4409 debugging info for the mips target).
4411 * DEC Alpha native support
4413 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4414 debug info, but GDB works fairly well with the DEC compiler and should
4415 work with a future GCC release. See the README file for a few
4416 Alpha-specific notes.
4418 * Preliminary thread implementation
4420 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4422 * LynxOS native and target support for 386
4424 This release has been hosted on LynxOS 2.2, and also can be configured
4425 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4428 * Improvements in C++ mangling/demangling.
4430 This release has much better g++ debugging, specifically in name
4431 mangling/demangling, virtual function calls, print virtual table,
4432 call methods, ...etc.
4434 *** Changes in GDB-4.10:
4436 * User visible changes:
4438 Remote debugging using the GDB-specific (`target remote') protocol now
4439 supports the `load' command. This is only useful if you have some
4440 other way of getting the stub to the target system, and you can put it
4441 somewhere in memory where it won't get clobbered by the download.
4443 Filename completion now works.
4445 When run under emacs mode, the "info line" command now causes the
4446 arrow to point to the line specified. Also, "info line" prints
4447 addresses in symbolic form (as well as hex).
4449 All vxworks based targets now support a user settable option, called
4450 vxworks-timeout. This option represents the number of seconds gdb
4451 should wait for responses to rpc's. You might want to use this if
4452 your vxworks target is, perhaps, a slow software simulator or happens
4453 to be on the far side of a thin network line.
4457 This release contains support for using a DEC alpha as a GDB host for
4458 cross debugging. Native alpha debugging is not supported yet.
4461 *** Changes in GDB-4.9:
4465 This is the first GDB release which is accompanied by a matching testsuite.
4466 The testsuite requires installation of dejagnu, which should be available
4467 via ftp from most sites that carry GNU software.
4471 'Cfront' style demangling has had its name changed to 'ARM' style, to
4472 emphasize that it was written from the specifications in the C++ Annotated
4473 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4474 disclaimers, it still generated too much confusion with users attempting to
4475 use gdb with AT&T cfront.
4479 GDB now uses a standard remote interface to a simulator library.
4480 So far, the library contains simulators for the Zilog Z8001/2, the
4481 Hitachi H8/300, H8/500 and Super-H.
4483 * New targets supported
4485 H8/300 simulator h8300-hitachi-hms or h8300hms
4486 H8/500 simulator h8500-hitachi-hms or h8500hms
4487 SH simulator sh-hitachi-hms or sh
4488 Z8000 simulator z8k-zilog-none or z8ksim
4489 IDT MIPS board over serial line mips-idt-ecoff
4491 Cross-debugging to GO32 targets is supported. It requires a custom
4492 version of the i386-stub.c module which is integrated with the
4493 GO32 memory extender.
4495 * New remote protocols
4497 MIPS remote debugging protocol.
4499 * New source languages supported
4501 This version includes preliminary support for Chill, a Pascal like language
4502 used by telecommunications companies. Chill support is also being integrated
4503 into the GNU compiler, but we don't know when it will be publically available.
4506 *** Changes in GDB-4.8:
4508 * HP Precision Architecture supported
4510 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4511 version of this support was available as a set of patches from the
4512 University of Utah. GDB does not support debugging of programs
4513 compiled with the HP compiler, because HP will not document their file
4514 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4515 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4517 Many problems in the preliminary version have been fixed.
4519 * Faster and better demangling
4521 We have improved template demangling and fixed numerous bugs in the GNU style
4522 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4523 character types (wchar_t) are now supported. Demangling of each symbol is now
4524 only done once, and is cached when the symbol table for a file is read in.
4525 This results in a small increase in memory usage for C programs, a moderate
4526 increase in memory usage for C++ programs, and a fantastic speedup in
4529 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4530 from the specifications in the Annotated Reference Manual, which AT&T's
4531 compiler does not actually implement.
4533 * G++ multiple inheritance compiler problem
4535 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4536 inheritance lattices was reworked to properly discover ambiguities. We
4537 recently found an example which causes this new algorithm to fail in a
4538 very subtle way, producing bad debug information for those classes.
4539 The file 'gcc.patch' (in this directory) can be applied to gcc to
4540 circumvent the problem. A future GCC release will contain a complete
4543 The previous G++ debug info problem (mentioned below for the gdb-4.7
4544 release) is fixed in gcc version 2.3.2.
4546 * Improved configure script
4548 The `configure' script will now attempt to guess your system type if
4549 you don't supply a host system type. The old scheme of supplying a
4550 host system triplet is preferable over using this. All the magic is
4551 done in the new `config.guess' script. Examine it for details.
4553 We have also brought our configure script much more in line with the FSF's
4554 version. It now supports the --with-xxx options. In particular,
4555 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4556 The resulting GDB will not be able to read arbitrary object file formats --
4557 only the format ``expected'' to be used on the configured target system.
4558 We hope to make this the default in a future release.
4560 * Documentation improvements
4562 There's new internal documentation on how to modify GDB, and how to
4563 produce clean changes to the code. We implore people to read it
4564 before submitting changes.
4566 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4567 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4568 `info' files are also provided. To build `info' files from scratch,
4569 you will need the latest `makeinfo' release, which will be available in
4570 a future texinfo-X.Y release.
4572 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4573 We're not sure exactly which versions have this problem, but it has
4574 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4575 or better. If that isn't possible, there is a patch in
4576 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4577 around this problem.
4581 GDB now supports array constants that can be used in expressions typed in by
4582 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4583 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4586 The new directory `gdb/sparclite' contains a program that demonstrates
4587 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4589 * New native hosts supported
4591 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4592 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4594 * New targets supported
4596 AMD 29k family via UDI a29k-amd-udi or udi29k
4598 * New file formats supported
4600 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4601 HPUX core files, and SCO 3.2v2 core files.
4605 Attaching to processes now works again; thanks for the many bug reports.
4607 We have also stomped on a bunch of core dumps caused by
4608 printf_filtered("%s") problems.
4610 We eliminated a copyright problem on the rpc and ptrace header files
4611 for VxWorks, which was discovered at the last minute during the 4.7
4612 release. You should now be able to build a VxWorks GDB.
4614 You can now interrupt gdb while an attached process is running. This
4615 will cause the attached process to stop, and give control back to GDB.
4617 We fixed problems caused by using too many file descriptors
4618 for reading symbols from object files and libraries. This was
4619 especially a problem for programs that used many (~100) shared
4622 The `step' command now only enters a subroutine if there is line number
4623 information for the subroutine. Otherwise it acts like the `next'
4624 command. Previously, `step' would enter subroutines if there was
4625 any debugging information about the routine. This avoids problems
4626 when using `cc -g1' on MIPS machines.
4628 * Internal improvements
4630 GDB's internal interfaces have been improved to make it easier to support
4631 debugging of multiple languages in the future.
4633 GDB now uses a common structure for symbol information internally.
4634 Minimal symbols (derived from linkage symbols in object files), partial
4635 symbols (from a quick scan of debug information), and full symbols
4636 contain a common subset of information, making it easier to write
4637 shared code that handles any of them.
4639 * New command line options
4641 We now accept --silent as an alias for --quiet.
4645 The memory-mapped-malloc library is now licensed under the GNU Library
4646 General Public License.
4648 *** Changes in GDB-4.7:
4650 * Host/native/target split
4652 GDB has had some major internal surgery to untangle the support for
4653 hosts and remote targets. Now, when you configure GDB for a remote
4654 target, it will no longer load in all of the support for debugging
4655 local programs on the host. When fully completed and tested, this will
4656 ensure that arbitrary host/target combinations are possible.
4658 The primary conceptual shift is to separate the non-portable code in
4659 GDB into three categories. Host specific code is required any time GDB
4660 is compiled on that host, regardless of the target. Target specific
4661 code relates to the peculiarities of the target, but can be compiled on
4662 any host. Native specific code is everything else: it can only be
4663 built when the host and target are the same system. Child process
4664 handling and core file support are two common `native' examples.
4666 GDB's use of /proc for controlling Unix child processes is now cleaner.
4667 It has been split out into a single module under the `target_ops' vector,
4668 plus two native-dependent functions for each system that uses /proc.
4670 * New hosts supported
4672 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4673 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4674 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4676 * New targets supported
4678 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4679 68030 and CPU32 m68030-*-*, m68332-*-*
4681 * New native hosts supported
4683 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4684 (386bsd is not well tested yet)
4685 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4687 * New file formats supported
4689 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4690 supports reading of `a.out.adobe' object files, which are an a.out
4691 format extended with minimal information about multiple sections.
4695 `show copying' is the same as the old `info copying'.
4696 `show warranty' is the same as `info warrantee'.
4697 These were renamed for consistency. The old commands continue to work.
4699 `info handle' is a new alias for `info signals'.
4701 You can now define pre-command hooks, which attach arbitrary command
4702 scripts to any command. The commands in the hook will be executed
4703 prior to the user's command. You can also create a hook which will be
4704 executed whenever the program stops. See gdb.texinfo.
4708 We now deal with Cfront style name mangling, and can even extract type
4709 info from mangled symbols. GDB can automatically figure out which
4710 symbol mangling style your C++ compiler uses.
4712 Calling of methods and virtual functions has been improved as well.
4716 The crash that occured when debugging Sun Ansi-C compiled binaries is
4717 fixed. This was due to mishandling of the extra N_SO stabs output
4720 We also finally got Ultrix 4.2 running in house, and fixed core file
4721 support, with help from a dozen people on the net.
4723 John M. Farrell discovered that the reason that single-stepping was so
4724 slow on all of the Mips based platforms (primarily SGI and DEC) was
4725 that we were trying to demangle and lookup a symbol used for internal
4726 purposes on every instruction that was being stepped through. Changing
4727 the name of that symbol so that it couldn't be mistaken for a C++
4728 mangled symbol sped things up a great deal.
4730 Rich Pixley sped up symbol lookups in general by getting much smarter
4731 about when C++ symbol mangling is necessary. This should make symbol
4732 completion (TAB on the command line) much faster. It's not as fast as
4733 we'd like, but it's significantly faster than gdb-4.6.
4737 A new user controllable variable 'call_scratch_address' can
4738 specify the location of a scratch area to be used when GDB
4739 calls a function in the target. This is necessary because the
4740 usual method of putting the scratch area on the stack does not work
4741 in systems that have separate instruction and data spaces.
4743 We integrated changes to support the 29k UDI (Universal Debugger
4744 Interface), but discovered at the last minute that we didn't have all
4745 of the appropriate copyright paperwork. We are working with AMD to
4746 resolve this, and hope to have it available soon.
4750 We have sped up the remote serial line protocol, especially for targets
4751 with lots of registers. It now supports a new `expedited status' ('T')
4752 message which can be used in place of the existing 'S' status message.
4753 This allows the remote stub to send only the registers that GDB
4754 needs to make a quick decision about single-stepping or conditional
4755 breakpoints, eliminating the need to fetch the entire register set for
4756 each instruction being stepped through.
4758 The GDB remote serial protocol now implements a write-through cache for
4759 registers, only re-reading the registers if the target has run.
4761 There is also a new remote serial stub for SPARC processors. You can
4762 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4763 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4764 processor with a serial port.
4768 Configure.in files have become much easier to read and modify. A new
4769 `table driven' format makes it more obvious what configurations are
4770 supported, and what files each one uses.
4774 There is a new opcodes library which will eventually contain all of the
4775 disassembly routines and opcode tables. At present, it only contains
4776 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4777 disassembler (binutils/objdump) to share these routines.
4779 The libiberty library is now copylefted under the GNU Library General
4780 Public License. This allows more liberal use, and was done so libg++
4781 can use it. This makes no difference to GDB, since the Library License
4782 grants all the rights from the General Public License.
4786 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4787 reference to the stabs symbol info used by the debugger. It is (as far
4788 as we know) the only published document on this fascinating topic. We
4789 encourage you to read it, compare it to the stabs information on your
4790 system, and send improvements on the document in general (to
4791 bug-gdb@prep.ai.mit.edu).
4793 And, of course, many bugs have been fixed.
4796 *** Changes in GDB-4.6:
4798 * Better support for C++ function names
4800 GDB now accepts as input the "demangled form" of C++ overloaded function
4801 names and member function names, and can do command completion on such names
4802 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4803 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4804 Make use of command completion, it is your friend.
4806 GDB also now accepts a variety of C++ mangled symbol formats. They are
4807 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4808 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4809 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4810 for the list of formats.
4812 * G++ symbol mangling problem
4814 Recent versions of gcc have a bug in how they emit debugging information for
4815 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4816 directory) can be applied to gcc to fix the problem. Alternatively, if you
4817 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4818 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4819 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4822 * New 'maintenance' command
4824 All of the commands related to hacking GDB internals have been moved out of
4825 the main command set, and now live behind the 'maintenance' command. This
4826 can also be abbreviated as 'mt'. The following changes were made:
4828 dump-me -> maintenance dump-me
4829 info all-breakpoints -> maintenance info breakpoints
4830 printmsyms -> maintenance print msyms
4831 printobjfiles -> maintenance print objfiles
4832 printpsyms -> maintenance print psymbols
4833 printsyms -> maintenance print symbols
4835 The following commands are new:
4837 maintenance demangle Call internal GDB demangler routine to
4838 demangle a C++ link name and prints the result.
4839 maintenance print type Print a type chain for a given symbol
4841 * Change to .gdbinit file processing
4843 We now read the $HOME/.gdbinit file before processing the argv arguments
4844 (e.g. reading symbol files or core files). This allows global parameters to
4845 be set, which will apply during the symbol reading. The ./.gdbinit is still
4846 read after argv processing.
4848 * New hosts supported
4850 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4852 GNU/Linux support i386-unknown-linux or linux
4854 We are also including code to support the HP/PA running BSD and HPUX. This
4855 is almost guaranteed not to work, as we didn't have time to test or build it
4856 for this release. We are including it so that the more adventurous (or
4857 masochistic) of you can play with it. We also had major problems with the
4858 fact that the compiler that we got from HP doesn't support the -g option.
4861 * New targets supported
4863 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4865 * More smarts about finding #include files
4867 GDB now remembers the compilation directory for all include files, and for
4868 all files from which C is generated (like yacc and lex sources). This
4869 greatly improves GDB's ability to find yacc/lex sources, and include files,
4870 especially if you are debugging your program from a directory different from
4871 the one that contains your sources.
4873 We also fixed a bug which caused difficulty with listing and setting
4874 breakpoints in include files which contain C code. (In the past, you had to
4875 try twice in order to list an include file that you hadn't looked at before.)
4877 * Interesting infernals change
4879 GDB now deals with arbitrary numbers of sections, where the symbols for each
4880 section must be relocated relative to that section's landing place in the
4881 target's address space. This work was needed to support ELF with embedded
4882 stabs used by Solaris-2.0.
4884 * Bug fixes (of course!)
4886 There have been loads of fixes for the following things:
4887 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4888 i960, stabs, DOS(GO32), procfs, etc...
4890 See the ChangeLog for details.
4892 *** Changes in GDB-4.5:
4894 * New machines supported (host and target)
4896 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4898 SGI Irix-4.x mips-sgi-irix4 or iris4
4900 * New malloc package
4902 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4903 Mmalloc is capable of handling mutiple heaps of memory. It is also
4904 capable of saving a heap to a file, and then mapping it back in later.
4905 This can be used to greatly speedup the startup of GDB by using a
4906 pre-parsed symbol table which lives in a mmalloc managed heap. For
4907 more details, please read mmalloc/mmalloc.texi.
4911 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4912 'help info proc' for details.
4914 * MIPS ecoff symbol table format
4916 The code that reads MIPS symbol table format is now supported on all hosts.
4917 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4920 * File name changes for MS-DOS
4922 Many files in the config directories have been renamed to make it easier to
4923 support GDB on MS-DOSe systems (which have very restrictive file name
4924 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4925 environment) is close to working but has some remaining problems. Note
4926 that debugging of DOS programs is not supported, due to limitations
4927 in the ``operating system'', but it can be used to host cross-debugging.
4929 * Cross byte order fixes
4931 Many fixes have been made to support cross debugging of Sparc and MIPS
4932 targets from hosts whose byte order differs.
4934 * New -mapped and -readnow options
4936 If memory-mapped files are available on your system through the 'mmap'
4937 system call, you can use the -mapped option on the `file' or
4938 `symbol-file' commands to cause GDB to write the symbols from your
4939 program into a reusable file. If the program you are debugging is
4940 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4941 Future GDB debugging sessions will notice the presence of this file,
4942 and will quickly map in symbol information from it, rather than reading
4943 the symbol table from the executable program. Using the '-mapped'
4944 option in a GDB `file' or `symbol-file' command has the same effect as
4945 starting GDB with the '-mapped' command-line option.
4947 You can cause GDB to read the entire symbol table immediately by using
4948 the '-readnow' option with any of the commands that load symbol table
4949 information (or on the GDB command line). This makes the command
4950 slower, but makes future operations faster.
4952 The -mapped and -readnow options are typically combined in order to
4953 build a `fred.syms' file that contains complete symbol information.
4954 A simple GDB invocation to do nothing but build a `.syms' file for future
4957 gdb -batch -nx -mapped -readnow programname
4959 The `.syms' file is specific to the host machine on which GDB is run.
4960 It holds an exact image of GDB's internal symbol table. It cannot be
4961 shared across multiple host platforms.
4963 * longjmp() handling
4965 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4966 siglongjmp() without losing control. This feature has not yet been ported to
4967 all systems. It currently works on many 386 platforms, all MIPS-based
4968 platforms (SGI, DECstation, etc), and Sun3/4.
4972 Preliminary work has been put in to support the new Solaris OS from Sun. At
4973 this time, it can control and debug processes, but it is not capable of
4978 As always, many many bug fixes. The major areas were with g++, and mipsread.
4979 People using the MIPS-based platforms should experience fewer mysterious
4980 crashes and trashed symbol tables.
4982 *** Changes in GDB-4.4:
4984 * New machines supported (host and target)
4986 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4988 BSD Reno on Vax vax-dec-bsd
4989 Ultrix on Vax vax-dec-ultrix
4991 * New machines supported (target)
4993 AMD 29000 embedded, using EBMON a29k-none-none
4997 GDB continues to improve its handling of C++. `References' work better.
4998 The demangler has also been improved, and now deals with symbols mangled as
4999 per the Annotated C++ Reference Guide.
5001 GDB also now handles `stabs' symbol information embedded in MIPS
5002 `ecoff' symbol tables. Since the ecoff format was not easily
5003 extensible to handle new languages such as C++, this appeared to be a
5004 good way to put C++ debugging info into MIPS binaries. This option
5005 will be supported in the GNU C compiler, version 2, when it is
5008 * New features for SVR4
5010 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5011 shared libraries. Debugging dynamically linked programs should present
5012 only minor differences from debugging statically linked programs.
5014 The `info proc' command will print out information about any process
5015 on an SVR4 system (including the one you are debugging). At the moment,
5016 it prints the address mappings of the process.
5018 If you bring up GDB on another SVR4 system, please send mail to
5019 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5021 * Better dynamic linking support in SunOS
5023 Reading symbols from shared libraries which contain debugging symbols
5024 now works properly. However, there remain issues such as automatic
5025 skipping of `transfer vector' code during function calls, which
5026 make it harder to debug code in a shared library, than to debug the
5027 same code linked statically.
5031 GDB is now using the latest `getopt' routines from the FSF. This
5032 version accepts the -- prefix for options with long names. GDB will
5033 continue to accept the old forms (-option and +option) as well.
5034 Various single letter abbreviations for options have been explicity
5035 added to the option table so that they won't get overshadowed in the
5036 future by other options that begin with the same letter.
5040 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5041 Many assorted bugs have been handled. Many more remain to be handled.
5042 See the various ChangeLog files (primarily in gdb and bfd) for details.
5045 *** Changes in GDB-4.3:
5047 * New machines supported (host and target)
5049 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5050 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5051 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5053 * Almost SCO Unix support
5055 We had hoped to support:
5056 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5057 (except for core file support), but we discovered very late in the release
5058 that it has problems with process groups that render gdb unusable. Sorry
5059 about that. I encourage people to fix it and post the fixes.
5061 * Preliminary ELF and DWARF support
5063 GDB can read ELF object files on System V Release 4, and can handle
5064 debugging records for C, in DWARF format, in ELF files. This support
5065 is preliminary. If you bring up GDB on another SVR4 system, please
5066 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5071 GDB now uses the latest `readline' library. One user-visible change
5072 is that two tabs will list possible command completions, which previously
5073 required typing M-? (meta-question mark, or ESC ?).
5077 The `stepi' bug that many of you noticed has been squashed.
5078 Many bugs in C++ have been handled. Many more remain to be handled.
5079 See the various ChangeLog files (primarily in gdb and bfd) for details.
5081 * State of the MIPS world (in case you wondered):
5083 GDB can understand the symbol tables emitted by the compilers
5084 supplied by most vendors of MIPS-based machines, including DEC. These
5085 symbol tables are in a format that essentially nobody else uses.
5087 Some versions of gcc come with an assembler post-processor called
5088 mips-tfile. This program is required if you want to do source-level
5089 debugging of gcc-compiled programs. I believe FSF does not ship
5090 mips-tfile with gcc version 1, but it will eventually come with gcc
5093 Debugging of g++ output remains a problem. g++ version 1.xx does not
5094 really support it at all. (If you're lucky, you should be able to get
5095 line numbers and stack traces to work, but no parameters or local
5096 variables.) With some work it should be possible to improve the
5099 When gcc version 2 is released, you will have somewhat better luck.
5100 However, even then you will get confusing results for inheritance and
5103 We will eventually provide full debugging of g++ output on
5104 DECstations. This will probably involve some kind of stabs-in-ecoff
5105 encapulation, but the details have not been worked out yet.
5108 *** Changes in GDB-4.2:
5110 * Improved configuration
5112 Only one copy of `configure' exists now, and it is not self-modifying.
5113 Porting BFD is simpler.
5117 The `step' and `next' commands now only stop at the first instruction
5118 of a source line. This prevents the multiple stops that used to occur
5119 in switch statements, for-loops, etc. `Step' continues to stop if a
5120 function that has debugging information is called within the line.
5124 Lots of small bugs fixed. More remain.
5126 * New host supported (not target)
5128 Intel 386 PC clone running Mach i386-none-mach
5131 *** Changes in GDB-4.1:
5133 * Multiple source language support
5135 GDB now has internal scaffolding to handle several source languages.
5136 It determines the type of each source file from its filename extension,
5137 and will switch expression parsing and number formatting to match the
5138 language of the function in the currently selected stack frame.
5139 You can also specifically set the language to be used, with
5140 `set language c' or `set language modula-2'.
5144 GDB now has preliminary support for the GNU Modula-2 compiler,
5145 currently under development at the State University of New York at
5146 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5147 continue through the fall of 1991 and into 1992.
5149 Other Modula-2 compilers are currently not supported, and attempting to
5150 debug programs compiled with them will likely result in an error as the
5151 symbol table is read. Feel free to work on it, though!
5153 There are hooks in GDB for strict type checking and range checking,
5154 in the `Modula-2 philosophy', but they do not currently work.
5158 GDB can now write to executable and core files (e.g. patch
5159 a variable's value). You must turn this switch on, specify
5160 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5161 by assigning a new value to a variable. Modifications take
5164 * Automatic SunOS shared library reading
5166 When you run your program, GDB automatically determines where its
5167 shared libraries (if any) have been loaded, and reads their symbols.
5168 The `share' command is no longer needed. This also works when
5169 examining core files.
5173 You can specify the number of lines that the `list' command shows.
5176 * New machines supported (host and target)
5178 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5179 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5180 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5182 * New hosts supported (not targets)
5184 IBM RT/PC: romp-ibm-aix or rtpc
5186 * New targets supported (not hosts)
5188 AMD 29000 embedded with COFF a29k-none-coff
5189 AMD 29000 embedded with a.out a29k-none-aout
5190 Ultracomputer remote kernel debug a29k-nyu-kern
5192 * New remote interfaces
5198 *** Changes in GDB-4.0:
5202 Wide output is wrapped at good places to make the output more readable.
5204 Gdb now supports cross-debugging from a host machine of one type to a
5205 target machine of another type. Communication with the target system
5206 is over serial lines. The ``target'' command handles connecting to the
5207 remote system; the ``load'' command will download a program into the
5208 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5209 also supports debugging of realtime processes running under VxWorks,
5210 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5211 stub on the target system.
5213 New CPUs supported include the AMD 29000 and Intel 960.
5215 GDB now reads object files and symbol tables via a ``binary file''
5216 library, which allows a single copy of GDB to debug programs of multiple
5217 object file types such as a.out and coff.
5219 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5220 refcard.dvi and refcard.ps are available to format it).
5223 * Control-Variable user interface simplified
5225 All variables that control the operation of the debugger can be set
5226 by the ``set'' command, and displayed by the ``show'' command.
5228 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5229 ``Show prompt'' produces the response:
5230 Gdb's prompt is new-gdb=>.
5232 What follows are the NEW set commands. The command ``help set'' will
5233 print a complete list of old and new set commands. ``help set FOO''
5234 will give a longer description of the variable FOO. ``show'' will show
5235 all of the variable descriptions and their current settings.
5237 confirm on/off: Enables warning questions for operations that are
5238 hard to recover from, e.g. rerunning the program while
5239 it is already running. Default is ON.
5241 editing on/off: Enables EMACS style command line editing
5242 of input. Previous lines can be recalled with
5243 control-P, the current line can be edited with control-B,
5244 you can search for commands with control-R, etc.
5247 history filename NAME: NAME is where the gdb command history
5248 will be stored. The default is .gdb_history,
5249 or the value of the environment variable
5252 history size N: The size, in commands, of the command history. The
5253 default is 256, or the value of the environment variable
5256 history save on/off: If this value is set to ON, the history file will
5257 be saved after exiting gdb. If set to OFF, the
5258 file will not be saved. The default is OFF.
5260 history expansion on/off: If this value is set to ON, then csh-like
5261 history expansion will be performed on
5262 command line input. The default is OFF.
5264 radix N: Sets the default radix for input and output. It can be set
5265 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5266 in the current radix, so "set radix 10" is always a no-op.
5268 height N: This integer value is the number of lines on a page. Default
5269 is 24, the current `stty rows'' setting, or the ``li#''
5270 setting from the termcap entry matching the environment
5273 width N: This integer value is the number of characters on a line.
5274 Default is 80, the current `stty cols'' setting, or the ``co#''
5275 setting from the termcap entry matching the environment
5278 Note: ``set screensize'' is obsolete. Use ``set height'' and
5279 ``set width'' instead.
5281 print address on/off: Print memory addresses in various command displays,
5282 such as stack traces and structure values. Gdb looks
5283 more ``symbolic'' if you turn this off; it looks more
5284 ``machine level'' with it on. Default is ON.
5286 print array on/off: Prettyprint arrays. New convenient format! Default
5289 print demangle on/off: Print C++ symbols in "source" form if on,
5292 print asm-demangle on/off: Same, for assembler level printouts
5295 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5298 * Support for Epoch Environment.
5300 The epoch environment is a version of Emacs v18 with windowing. One
5301 new command, ``inspect'', is identical to ``print'', except that if you
5302 are running in the epoch environment, the value is printed in its own
5306 * Support for Shared Libraries
5308 GDB can now debug programs and core files that use SunOS shared libraries.
5309 Symbols from a shared library cannot be referenced
5310 before the shared library has been linked with the program (this
5311 happens after you type ``run'' and before the function main() is entered).
5312 At any time after this linking (including when examining core files
5313 from dynamically linked programs), gdb reads the symbols from each
5314 shared library when you type the ``sharedlibrary'' command.
5315 It can be abbreviated ``share''.
5317 sharedlibrary REGEXP: Load shared object library symbols for files
5318 matching a unix regular expression. No argument
5319 indicates to load symbols for all shared libraries.
5321 info sharedlibrary: Status of loaded shared libraries.
5326 A watchpoint stops execution of a program whenever the value of an
5327 expression changes. Checking for this slows down execution
5328 tremendously whenever you are in the scope of the expression, but is
5329 quite useful for catching tough ``bit-spreader'' or pointer misuse
5330 problems. Some machines such as the 386 have hardware for doing this
5331 more quickly, and future versions of gdb will use this hardware.
5333 watch EXP: Set a watchpoint (breakpoint) for an expression.
5335 info watchpoints: Information about your watchpoints.
5337 delete N: Deletes watchpoint number N (same as breakpoints).
5338 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5339 enable N: Re-enables watchpoint number N (same as breakpoints).
5342 * C++ multiple inheritance
5344 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5347 * C++ exception handling
5349 Gdb now supports limited C++ exception handling. Besides the existing
5350 ability to breakpoint on an exception handler, gdb can breakpoint on
5351 the raising of an exception (before the stack is peeled back to the
5354 catch FOO: If there is a FOO exception handler in the dynamic scope,
5355 set a breakpoint to catch exceptions which may be raised there.
5356 Multiple exceptions (``catch foo bar baz'') may be caught.
5358 info catch: Lists all exceptions which may be caught in the
5359 current stack frame.
5362 * Minor command changes
5364 The command ``call func (arg, arg, ...)'' now acts like the print
5365 command, except it does not print or save a value if the function's result
5366 is void. This is similar to dbx usage.
5368 The ``up'' and ``down'' commands now always print the frame they end up
5369 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5370 frames without printing.
5372 * New directory command
5374 'dir' now adds directories to the FRONT of the source search path.
5375 The path starts off empty. Source files that contain debug information
5376 about the directory in which they were compiled can be found even
5377 with an empty path; Sun CC and GCC include this information. If GDB can't
5378 find your source file in the current directory, type "dir .".
5380 * Configuring GDB for compilation
5382 For normal use, type ``./configure host''. See README or gdb.texinfo
5385 GDB now handles cross debugging. If you are remotely debugging between
5386 two different machines, type ``./configure host -target=targ''.
5387 Host is the machine where GDB will run; targ is the machine
5388 where the program that you are debugging will run.