1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.6
6 * New convenience function "$_isvoid", to check whether an expression
7 is void. A void expression is an expression where the type of the
8 result is "void". For example, some convenience variables may be
9 "void" when evaluated (e.g., "$_exitcode" before the execution of
10 the program being debugged; or an undefined convenience variable).
11 Another example, when calling a function whose return type is
14 * The "maintenance print objfiles" command now takes an optional regexp.
16 * The "catch syscall" command now works on arm*-linux* targets.
18 * GDB now consistently shows "<not saved>" when printing values of
19 registers the debug info indicates have not been saved in the frame
20 and there's nowhere to retrieve them from
21 (callee-saved/call-clobbered registers):
26 (gdb) info registers rax
29 Before, the former would print "<optimized out>", and the latter
30 "*value not available*".
34 ** Frame filters and frame decorators have been added.
38 Nios II ELF nios2*-*-elf
39 Nios II GNU/Linux nios2*-*-linux
40 Texas Instruments MSP430 msp430*-*-elf
42 * Removed native configurations
44 Support for these a.out NetBSD and OpenBSD obsolete configurations has
45 been removed. ELF variants of these configurations are kept supported.
47 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
48 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
49 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
50 i[34567]86-*-openbsd3.[0-3]
51 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
52 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
53 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
57 Like "catch throw", but catches a re-thrown exception.
59 Renamed from old "maint check-symtabs".
61 Perform consistency checks on symtabs.
63 Expand symtabs matching an optional regexp.
66 Display the details of GDB configure-time options.
68 maint set|show per-command
69 maint set|show per-command space
70 maint set|show per-command time
71 maint set|show per-command symtab
72 Enable display of per-command gdb resource usage.
76 set debug symfile off|on
78 Control display of debugging info regarding reading symbol files and
79 symbol tables within those files
81 set print raw frame-arguments
82 show print raw frame-arguments
83 Set/show whether to print frame arguments in raw mode,
84 disregarding any defined pretty-printers.
86 set remote trace-status-packet
87 show remote trace-status-packet
88 Set/show the use of remote protocol qTStatus packet.
92 Control display of debugging messages related to Nios II targets.
96 Control whether target-assisted range stepping is enabled.
98 * You can now use a literal value 'unlimited' for options that
99 interpret 0 or -1 as meaning "unlimited". E.g., "set
100 trace-buffer-size unlimited" is now an alias for "set
101 trace-buffer-size -1" and "set height unlimited" is now an alias for
104 * New command-line options
106 Display the details of GDB configure-time options.
108 * The command 'tsave' can now support new option '-ctf' to save trace
109 buffer in Common Trace Format.
111 * Newly installed $prefix/bin/gcore acts as a shell interface for the
114 * GDB now implements the the C++ 'typeid' operator.
116 * The new convenience variable $_exception holds the exception being
117 thrown or caught at an exception-related catchpoint.
119 * The exception-related catchpoints, like "catch throw", now accept a
120 regular expression which can be used to filter exceptions by type.
124 ** The -trace-save MI command can optionally save trace buffer in Common
127 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
129 ** The command -data-list-register-values now accepts an optional
130 "--skip-unavailable" option. When used, only the available registers
133 ** The new command -trace-frame-collected dumps collected variables,
134 computed expressions, tvars, memory and registers in a traceframe.
136 ** The commands -stack-list-locals, -stack-list-arguments and
137 -stack-list-variables now accept an option "--skip-unavailable".
138 When used, only the available locals or arguments are displayed.
140 * New system-wide configuration scripts
141 A GDB installation now provides scripts suitable for use as system-wide
142 configuration scripts for the following systems:
146 * GDB now supports target-assigned range stepping with remote targets.
147 This improves the performance of stepping source lines by reducing
148 the number of control packets from/to GDB. See "New remote packets"
151 * GDB now understands the element 'tvar' in the XML traceframe info.
152 It has the id of the collected trace state variables.
154 * On S/390 targets that provide the transactional-execution feature,
155 the program interruption transaction diagnostic block (TDB) is now
156 represented as a number of additional "registers" in GDB.
162 The vCont packet supports a new 'r' action, that tells the remote
163 stub to step through an address range itself, without GDB
164 involvemement at each single-step.
166 qXfer:libraries-svr4:read's annex
167 The previously unused annex of the qXfer:libraries-svr4:read packet
168 is now used to support passing an argument list. The remote stub
169 reports support for this argument list to GDB's qSupported query.
170 The defined arguments are "start" and "prev", used to reduce work
171 necessary for library list updating, resulting in significant
174 * New features in the GDB remote stub, GDBserver
176 ** GDBserver now supports target-assisted range stepping. Currently
177 enabled on x86/x86_64 GNU/Linux targets.
179 ** GDBserver now adds element 'tvar' in the XML in the reply to
180 'qXfer:traceframe-info:read'. It has the id of the collected
181 trace state variables.
183 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
186 * New 'z' formatter for printing and examining memory, this displays the
187 value as hexadecimal zero padded on the left to the size of the type.
189 * GDB can now use Windows x64 unwinding data.
191 *** Changes in GDB 7.6
193 * Target record has been renamed to record-full.
194 Record/replay is now enabled with the "record full" command.
195 This also affects settings that are associated with full record/replay
196 that have been moved from "set/show record" to "set/show record full":
198 set|show record full insn-number-max
199 set|show record full stop-at-limit
200 set|show record full memory-query
202 * A new record target "record-btrace" has been added. The new target
203 uses hardware support to record the control-flow of a process. It
204 does not support replaying the execution, but it implements the
205 below new commands for investigating the recorded execution log.
206 This new recording method can be enabled using:
210 The "record-btrace" target is only available on Intel Atom processors
211 and requires a Linux kernel 2.6.32 or later.
213 * Two new commands have been added for record/replay to give information
214 about the recorded execution without having to replay the execution.
215 The commands are only supported by "record btrace".
217 record instruction-history prints the execution history at
218 instruction granularity
220 record function-call-history prints the execution history at
223 * New native configurations
225 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
226 FreeBSD/powerpc powerpc*-*-freebsd
227 x86_64/Cygwin x86_64-*-cygwin*
228 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
232 ARM AArch64 aarch64*-*-elf
233 ARM AArch64 GNU/Linux aarch64*-*-linux
234 Lynx 178 PowerPC powerpc-*-lynx*178
235 x86_64/Cygwin x86_64-*-cygwin*
236 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
238 * If the configured location of system.gdbinit file (as given by the
239 --with-system-gdbinit option at configure time) is in the
240 data-directory (as specified by --with-gdb-datadir at configure
241 time) or in one of its subdirectories, then GDB will look for the
242 system-wide init file in the directory specified by the
243 --data-directory command-line option.
245 * New command line options:
247 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
248 other initialization files, unlike -nx which disables all of them.
250 * Removed command line options
252 -epoch This was used by the gdb mode in Epoch, an ancient fork of
255 * The 'ptype' and 'whatis' commands now accept an argument to control
258 * 'info proc' now works on some core files.
262 ** Vectors can be created with gdb.Type.vector.
264 ** Python's atexit.register now works in GDB.
266 ** Types can be pretty-printed via a Python API.
268 ** Python 3 is now supported (in addition to Python 2.4 or later)
270 ** New class gdb.Architecture exposes GDB's internal representation
271 of architecture in the Python API.
273 ** New method Frame.architecture returns the gdb.Architecture object
274 corresponding to the frame's architecture.
276 * New Python-based convenience functions:
278 ** $_memeq(buf1, buf2, length)
279 ** $_streq(str1, str2)
281 ** $_regex(str, regex)
283 * The 'cd' command now defaults to using '~' (the home directory) if not
286 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
287 default for GCC since November 2000.
289 * The command 'forward-search' can now be abbreviated as 'fo'.
291 * The command 'info tracepoints' can now display 'installed on target'
292 or 'not installed on target' for each non-pending location of tracepoint.
294 * New configure options
296 --enable-libmcheck/--disable-libmcheck
297 By default, development versions are built with -lmcheck on hosts
298 that support it, in order to help track memory corruption issues.
299 Release versions, on the other hand, are built without -lmcheck
300 by default. The --enable-libmcheck/--disable-libmcheck configure
301 options allow the user to override that default.
302 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
303 This configure option allows the user to build GDB with
304 libbabeltrace using which GDB can read Common Trace Format data.
306 * New commands (for set/show, see "New options" below)
309 Catch signals. This is similar to "handle", but allows commands and
310 conditions to be attached.
313 List the BFDs known to GDB.
315 python-interactive [command]
317 Start a Python interactive prompt, or evaluate the optional command
318 and print the result of expressions.
321 "py" is a new alias for "python".
323 enable type-printer [name]...
324 disable type-printer [name]...
325 Enable or disable type printers.
329 ** For the Renesas Super-H architecture, the "regs" command has been removed
330 (has been deprecated in GDB 7.5), and "info all-registers" should be used
335 set print type methods (on|off)
336 show print type methods
337 Control whether method declarations are displayed by "ptype".
338 The default is to show them.
340 set print type typedefs (on|off)
341 show print type typedefs
342 Control whether typedef definitions are displayed by "ptype".
343 The default is to show them.
345 set filename-display basename|relative|absolute
346 show filename-display
347 Control the way in which filenames is displayed.
348 The default is "relative", which preserves previous behavior.
350 set trace-buffer-size
351 show trace-buffer-size
352 Request target to change the size of trace buffer.
354 set remote trace-buffer-size-packet auto|on|off
355 show remote trace-buffer-size-packet
356 Control the use of the remote protocol `QTBuffer:size' packet.
360 Control display of debugging messages related to ARM AArch64.
363 set debug coff-pe-read
364 show debug coff-pe-read
365 Control display of debugging messages related to reading of COFF/PE
370 Control display of debugging messages related to Mach-O symbols
373 set debug notification
374 show debug notification
375 Control display of debugging info for async remote notification.
379 ** Command parameter changes are now notified using new async record
380 "=cmd-param-changed".
381 ** Trace frame changes caused by command "tfind" are now notified using
382 new async record "=traceframe-changed".
383 ** The creation, deletion and modification of trace state variables
384 are now notified using new async records "=tsv-created",
385 "=tsv-deleted" and "=tsv-modified".
386 ** The start and stop of process record are now notified using new
387 async record "=record-started" and "=record-stopped".
388 ** Memory changes are now notified using new async record
390 ** The data-disassemble command response will include a "fullname" field
391 containing the absolute file name when source has been requested.
392 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
393 command, to allow pattern filling of memory areas.
394 ** New commands "-catch-load"/"-catch-unload" added for intercepting
395 library load/unload events.
396 ** The response to breakpoint commands and breakpoint async records
397 includes an "installed" field containing a boolean state about each
398 non-pending tracepoint location is whether installed on target or not.
399 ** Output of the "-trace-status" command includes a "trace-file" field
400 containing the name of the trace file being examined. This field is
401 optional, and only present when examining a trace file.
402 ** The "fullname" field is now always present along with the "file" field,
403 even if the file cannot be found by GDB.
405 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
406 You must have the LZMA library available when configuring GDB for this
407 feature to be enabled. For more information, see:
408 http://fedoraproject.org/wiki/Features/MiniDebugInfo
413 Set the size of trace buffer. The remote stub reports support for this
414 packet to gdb's qSupported query.
417 Enable Branch Trace Store (BTS)-based branch tracing for the current
418 thread. The remote stub reports support for this packet to gdb's
422 Disable branch tracing for the current thread. The remote stub reports
423 support for this packet to gdb's qSupported query.
426 Read the traced branches for the current thread. The remote stub
427 reports support for this packet to gdb's qSupported query.
429 *** Changes in GDB 7.5
431 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
432 for more x32 ABI info.
434 * GDB now supports access to MIPS DSP registers on Linux targets.
436 * GDB now supports debugging microMIPS binaries.
438 * The "info os" command on GNU/Linux can now display information on
439 several new classes of objects managed by the operating system:
440 "info os procgroups" lists process groups
441 "info os files" lists file descriptors
442 "info os sockets" lists internet-domain sockets
443 "info os shm" lists shared-memory regions
444 "info os semaphores" lists semaphores
445 "info os msg" lists message queues
446 "info os modules" lists loaded kernel modules
448 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
449 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
450 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
451 options and inspect the probe arguments using the new $_probe_arg family
452 of convenience variables. You can obtain more information about SystemTap
453 in <http://sourceware.org/systemtap/>.
455 * GDB now supports reversible debugging on ARM, it allows you to
456 debug basic ARM and THUMB instructions, and provides
457 record/replay support.
459 * The option "symbol-reloading" has been deleted as it is no longer used.
463 ** GDB commands implemented in Python can now be put in command class
466 ** The "maint set python print-stack on|off" is now deleted.
468 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
469 apply "flag enum"-style pretty-printing to any enum.
471 ** gdb.lookup_symbol can now work when there is no current frame.
473 ** gdb.Symbol now has a 'line' attribute, holding the line number in
474 the source at which the symbol was defined.
476 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
477 method 'value'. The former indicates whether the symbol needs a
478 frame in order to compute its value, and the latter computes the
481 ** A new method 'referenced_value' on gdb.Value objects which can
482 dereference pointer as well as C++ reference values.
484 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
485 which return the global and static blocks (as gdb.Block objects),
486 of the underlying symbol table, respectively.
488 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
489 object associated with a PC value.
491 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
492 of the address range occupied by code for the current source line.
494 * Go language support.
495 GDB now supports debugging programs written in the Go programming
498 * GDBserver now supports stdio connections.
499 E.g. (gdb) target remote | ssh myhost gdbserver - hello
501 * The binary "gdbtui" can no longer be built or installed.
502 Use "gdb -tui" instead.
504 * GDB will now print "flag" enums specially. A flag enum is one where
505 all the enumerator values have no bits in common when pairwise
506 "and"ed. When printing a value whose type is a flag enum, GDB will
507 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
508 (gdb) print (enum E) 3
511 * The filename part of a linespec will now match trailing components
512 of a source file name. For example, "break gcc/expr.c:1000" will
513 now set a breakpoint in build/gcc/expr.c, but not
516 * The "info proc" and "generate-core-file" commands will now also
517 work on remote targets connected to GDBserver on Linux.
519 * The command "info catch" has been removed. It has been disabled
522 * The "catch exception" and "catch assert" commands now accept
523 a condition at the end of the command, much like the "break"
524 command does. For instance:
526 (gdb) catch exception Constraint_Error if Barrier = True
528 Previously, it was possible to add a condition to such catchpoints,
529 but it had to be done as a second step, after the catchpoint had been
530 created, using the "condition" command.
532 * The "info static-tracepoint-marker" command will now also work on
533 native Linux targets with in-process agent.
535 * GDB can now set breakpoints on inlined functions.
537 * The .gdb_index section has been updated to include symbols for
538 inlined functions. GDB will ignore older .gdb_index sections by
539 default, which could cause symbol files to be loaded more slowly
540 until their .gdb_index sections can be recreated. The new command
541 "set use-deprecated-index-sections on" will cause GDB to use any older
542 .gdb_index sections it finds. This will restore performance, but the
543 ability to set breakpoints on inlined functions will be lost in symbol
544 files with older .gdb_index sections.
546 The .gdb_index section has also been updated to record more information
547 about each symbol. This speeds up the "info variables", "info functions"
548 and "info types" commands when used with programs having the .gdb_index
549 section, as well as speeding up debugging with shared libraries using
550 the .gdb_index section.
552 * Ada support for GDB/MI Variable Objects has been added.
554 * GDB can now support 'breakpoint always-inserted mode' in 'record'
559 ** New command -info-os is the MI equivalent of "info os".
561 ** Output logs ("set logging" and related) now include MI output.
565 ** "set use-deprecated-index-sections on|off"
566 "show use-deprecated-index-sections on|off"
567 Controls the use of deprecated .gdb_index sections.
569 ** "catch load" and "catch unload" can be used to stop when a shared
570 library is loaded or unloaded, respectively.
572 ** "enable count" can be used to auto-disable a breakpoint after
575 ** "info vtbl" can be used to show the virtual method tables for
576 C++ and Java objects.
578 ** "explore" and its sub commands "explore value" and "explore type"
579 can be used to reccursively explore values and types of
580 expressions. These commands are available only if GDB is
581 configured with '--with-python'.
583 ** "info auto-load" shows status of all kinds of auto-loaded files,
584 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
585 sequences of commands files, "info auto-load python-scripts"
586 shows status of auto-loading Python script files,
587 "info auto-load local-gdbinit" shows status of loading init file
588 (.gdbinit) from current directory and "info auto-load libthread-db" shows
589 status of inferior specific thread debugging shared library loading.
591 ** "info auto-load-scripts", "set auto-load-scripts on|off"
592 and "show auto-load-scripts" commands have been deprecated, use their
593 "info auto-load python-scripts", "set auto-load python-scripts on|off"
594 and "show auto-load python-scripts" counterparts instead.
596 ** "dprintf location,format,args..." creates a dynamic printf, which
597 is basically a breakpoint that does a printf and immediately
598 resumes your program's execution, so it is like a printf that you
599 can insert dynamically at runtime instead of at compiletime.
601 ** "set print symbol"
603 Controls whether GDB attempts to display the symbol, if any,
604 corresponding to addresses it prints. This defaults to "on", but
605 you can set it to "off" to restore GDB's previous behavior.
607 * Deprecated commands
609 ** For the Renesas Super-H architecture, the "regs" command has been
610 deprecated, and "info all-registers" should be used instead.
614 Renesas RL78 rl78-*-elf
615 HP OpenVMS ia64 ia64-hp-openvms*
617 * GDBserver supports evaluation of breakpoint conditions. When
618 support is advertised by GDBserver, GDB may be told to send the
619 breakpoint conditions in bytecode form to GDBserver. GDBserver
620 will only report the breakpoint trigger to GDB when its condition
626 show mips compression
627 Select the compressed ISA encoding used in functions that have no symbol
628 information available. The encoding can be set to either of:
631 and is updated automatically from ELF file flags if available.
633 set breakpoint condition-evaluation
634 show breakpoint condition-evaluation
635 Control whether breakpoint conditions are evaluated by GDB ("host") or by
636 GDBserver ("target"). Default option "auto" chooses the most efficient
638 This option can improve debugger efficiency depending on the speed of the
642 Disable auto-loading globally.
645 Show auto-loading setting of all kinds of auto-loaded files.
647 set auto-load gdb-scripts on|off
648 show auto-load gdb-scripts
649 Control auto-loading of GDB canned sequences of commands files.
651 set auto-load python-scripts on|off
652 show auto-load python-scripts
653 Control auto-loading of Python script files.
655 set auto-load local-gdbinit on|off
656 show auto-load local-gdbinit
657 Control loading of init file (.gdbinit) from current directory.
659 set auto-load libthread-db on|off
660 show auto-load libthread-db
661 Control auto-loading of inferior specific thread debugging shared library.
663 set auto-load scripts-directory <dir1>[:<dir2>...]
664 show auto-load scripts-directory
665 Set a list of directories from which to load auto-loaded scripts.
666 Automatically loaded Python scripts and GDB scripts are located in one
667 of the directories listed by this option.
668 The delimiter (':' above) may differ according to the host platform.
670 set auto-load safe-path <dir1>[:<dir2>...]
671 show auto-load safe-path
672 Set a list of directories from which it is safe to auto-load files.
673 The delimiter (':' above) may differ according to the host platform.
675 set debug auto-load on|off
677 Control display of debugging info for auto-loading the files above.
679 set dprintf-style gdb|call|agent
681 Control the way in which a dynamic printf is performed; "gdb"
682 requests a GDB printf command, while "call" causes dprintf to call a
683 function in the inferior. "agent" requests that the target agent
684 (such as GDBserver) do the printing.
686 set dprintf-function <expr>
687 show dprintf-function
688 set dprintf-channel <expr>
690 Set the function and optional first argument to the call when using
691 the "call" style of dynamic printf.
693 set disconnected-dprintf on|off
694 show disconnected-dprintf
695 Control whether agent-style dynamic printfs continue to be in effect
696 after GDB disconnects.
698 * New configure options
701 Configure default value for the 'set auto-load scripts-directory'
702 setting above. It defaults to '$debugdir:$datadir/auto-load',
703 $debugdir representing global debugging info directories (available
704 via 'show debug-file-directory') and $datadir representing GDB's data
705 directory (available via 'show data-directory').
707 --with-auto-load-safe-path
708 Configure default value for the 'set auto-load safe-path' setting
709 above. It defaults to the --with-auto-load-dir setting.
711 --without-auto-load-safe-path
712 Set 'set auto-load safe-path' to '/', effectively disabling this
717 z0/z1 conditional breakpoints extension
719 The z0/z1 breakpoint insertion packets have been extended to carry
720 a list of conditional expressions over to the remote stub depending on the
721 condition evaluation mode. The use of this extension can be controlled
722 via the "set remote conditional-breakpoints-packet" command.
726 Specify the signals which the remote stub may pass to the debugged
727 program without GDB involvement.
729 * New command line options
731 --init-command=FILE, -ix Like --command, -x but execute it
732 before loading inferior.
733 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
734 execute it before loading inferior.
736 *** Changes in GDB 7.4
738 * GDB now handles ambiguous linespecs more consistently; the existing
739 FILE:LINE support has been expanded to other types of linespecs. A
740 breakpoint will now be set on all matching locations in all
741 inferiors, and locations will be added or removed according to
744 * GDB now allows you to skip uninteresting functions and files when
745 stepping with the "skip function" and "skip file" commands.
747 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
748 and "show remote hardware-watchpoint-length-limit". These allows to
749 set or show the maximum length limit (in bytes) of a remote
750 target hardware watchpoint.
752 This allows e.g. to use "unlimited" hardware watchpoints with the
753 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
754 watchpoints are slower than real hardware watchpoints but are
755 significantly faster than gdb software watchpoints.
759 ** The register_pretty_printer function in module gdb.printing now takes
760 an optional `replace' argument. If True, the new printer replaces any
763 ** The "maint set python print-stack on|off" command has been
764 deprecated and will be deleted in GDB 7.5.
765 A new command: "set python print-stack none|full|message" has
766 replaced it. Additionally, the default for "print-stack" is
767 now "message", which just prints the error message without
770 ** A prompt substitution hook (prompt_hook) is now available to the
773 ** A new Python module, gdb.prompt has been added to the GDB Python
774 modules library. This module provides functionality for
775 escape sequences in prompts (used by set/show
776 extended-prompt). These escape sequences are replaced by their
779 ** Python commands and convenience-functions located in
780 'data-directory'/python/gdb/command and
781 'data-directory'/python/gdb/function are now automatically loaded
784 ** Blocks now provide four new attributes. global_block and
785 static_block will return the global and static blocks
786 respectively. is_static and is_global are boolean attributes
787 that indicate if the block is one of those two types.
789 ** Symbols now provide the "type" attribute, the type of the symbol.
791 ** The "gdb.breakpoint" function has been deprecated in favor of
794 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
795 of a function. This class is based on the "finish" command
796 available in the CLI.
798 ** Type objects for struct and union types now allow access to
799 the fields using standard Python dictionary (mapping) methods.
800 For example, "some_type['myfield']" now works, as does
803 ** A new event "gdb.new_objfile" has been added, triggered by loading a
806 ** A new function, "deep_items" has been added to the gdb.types
807 module in the GDB Python modules library. This function returns
808 an iterator over the fields of a struct or union type. Unlike
809 the standard Python "iteritems" method, it will recursively traverse
810 any anonymous fields.
814 ** "*stopped" events can report several new "reason"s, such as
817 ** Breakpoint changes are now notified using new async records, like
818 "=breakpoint-modified".
820 ** New command -ada-task-info.
822 * libthread-db-search-path now supports two special values: $sdir and $pdir.
823 $sdir specifies the default system locations of shared libraries.
824 $pdir specifies the directory where the libpthread used by the application
827 GDB no longer looks in $sdir and $pdir after it has searched the directories
828 mentioned in libthread-db-search-path. If you want to search those
829 directories, they must be specified in libthread-db-search-path.
830 The default value of libthread-db-search-path on GNU/Linux and Solaris
831 systems is now "$sdir:$pdir".
833 $pdir is not supported by gdbserver, it is currently ignored.
834 $sdir is supported by gdbserver.
836 * New configure option --with-iconv-bin.
837 When using the internationalization support like the one in the GNU C
838 library, GDB will invoke the "iconv" program to get a list of supported
839 character sets. If this program lives in a non-standard location, one can
840 use this option to specify where to find it.
842 * When natively debugging programs on PowerPC BookE processors running
843 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
844 watchpoints, which specify a mask in addition to an address to watch.
845 The mask specifies that some bits of an address (the bits which are
846 reset in the mask) should be ignored when matching the address accessed
847 by the inferior against the watchpoint address. See the "PowerPC Embedded"
848 section in the user manual for more details.
850 * The new option --once causes GDBserver to stop listening for connections once
851 the first connection is made. The listening port used by GDBserver will
852 become available after that.
854 * New commands "info macros" and "alias" have been added.
856 * New function parameters suffix @entry specifies value of function parameter
857 at the time the function got called. Entry values are available only since
863 "!" is now an alias of the "shell" command.
864 Note that no space is needed between "!" and SHELL COMMAND.
868 watch EXPRESSION mask MASK_VALUE
869 The watch command now supports the mask argument which allows creation
870 of masked watchpoints, if the current architecture supports this feature.
872 info auto-load-scripts [REGEXP]
873 This command was formerly named "maintenance print section-scripts".
874 It is now generally useful and is no longer a maintenance-only command.
876 info macro [-all] [--] MACRO
877 The info macro command has new options `-all' and `--'. The first for
878 printing all definitions of a macro. The second for explicitly specifying
879 the end of arguments and the beginning of the macro name in case the macro
880 name starts with a hyphen.
882 collect[/s] EXPRESSIONS
883 The tracepoint collect command now takes an optional modifier "/s"
884 that directs it to dereference pointer-to-character types and
885 collect the bytes of memory up to a zero byte. The behavior is
886 similar to what you see when you use the regular print command on a
887 string. An optional integer following the "/s" sets a bound on the
888 number of bytes that will be collected.
891 The trace start command now interprets any supplied arguments as a
892 note to be recorded with the trace run, with an effect similar to
893 setting the variable trace-notes.
896 The trace stop command now interprets any arguments as a note to be
897 mentioned along with the tstatus report that the trace was stopped
898 with a command. The effect is similar to setting the variable
901 * Tracepoints can now be enabled and disabled at any time after a trace
902 experiment has been started using the standard "enable" and "disable"
903 commands. It is now possible to start a trace experiment with no enabled
904 tracepoints; GDB will display a warning, but will allow the experiment to
905 begin, assuming that tracepoints will be enabled as needed while the trace
908 * Fast tracepoints on 32-bit x86-architectures can now be placed at
909 locations with 4-byte instructions, when they were previously
910 limited to locations with instructions of 5 bytes or longer.
914 set debug dwarf2-read
915 show debug dwarf2-read
916 Turns on or off display of debugging messages related to reading
917 DWARF debug info. The default is off.
919 set debug symtab-create
920 show debug symtab-create
921 Turns on or off display of debugging messages related to symbol table
922 creation. The default is off.
926 Set the GDB prompt, and allow escape sequences to be inserted to
927 display miscellaneous information (see 'help set extended-prompt'
928 for the list of sequences). This prompt (and any information
929 accessed through the escape sequences) is updated every time the
932 set print entry-values (both|compact|default|if-needed|no|only|preferred)
933 show print entry-values
934 Set printing of frame argument values at function entry. In some cases
935 GDB can determine the value of function argument which was passed by the
936 function caller, even if the value was modified inside the called function.
938 set debug entry-values
939 show debug entry-values
940 Control display of debugging info for determining frame argument values at
941 function entry and virtual tail call frames.
943 set basenames-may-differ
944 show basenames-may-differ
945 Set whether a source file may have multiple base names.
946 (A "base name" is the name of a file with the directory part removed.
947 Example: The base name of "/home/user/hello.c" is "hello.c".)
948 If set, GDB will canonicalize file names (e.g., expand symlinks)
949 before comparing them. Canonicalization is an expensive operation,
950 but it allows the same file be known by more than one base name.
951 If not set (the default), all source files are assumed to have just
952 one base name, and gdb will do file name comparisons more efficiently.
958 Set a user name and notes for the current and any future trace runs.
959 This is useful for long-running and/or disconnected traces, to
960 inform others (or yourself) as to who is running the trace, supply
961 contact information, or otherwise explain what is going on.
964 show trace-stop-notes
965 Set a note attached to the trace run, that is displayed when the
966 trace has been stopped by a tstop command. This is useful for
967 instance as an explanation, if you are stopping a trace run that was
968 started by someone else.
974 Dynamically enable a tracepoint in a started trace experiment.
978 Dynamically disable a tracepoint in a started trace experiment.
982 Set the user and notes of the trace run.
986 Query the current status of a tracepoint.
990 Query the minimum length of instruction at which a fast tracepoint may
993 * Dcache size (number of lines) and line-size are now runtime-configurable
994 via "set dcache line" and "set dcache line-size" commands.
998 Texas Instruments TMS320C6x tic6x-*-*
1002 Renesas RL78 rl78-*-elf
1004 *** Changes in GDB 7.3.1
1006 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1008 *** Changes in GDB 7.3
1010 * GDB has a new command: "thread find [REGEXP]".
1011 It finds the thread id whose name, target id, or thread extra info
1012 matches the given regular expression.
1014 * The "catch syscall" command now works on mips*-linux* targets.
1016 * The -data-disassemble MI command now supports modes 2 and 3 for
1017 dumping the instruction opcodes.
1019 * New command line options
1021 -data-directory DIR Specify DIR as the "data-directory".
1022 This is mostly for testing purposes.
1024 * The "maint set python auto-load on|off" command has been renamed to
1025 "set auto-load-scripts on|off".
1027 * GDB has a new command: "set directories".
1028 It is like the "dir" command except that it replaces the
1029 source path list instead of augmenting it.
1031 * GDB now understands thread names.
1033 On GNU/Linux, "info threads" will display the thread name as set by
1034 prctl or pthread_setname_np.
1036 There is also a new command, "thread name", which can be used to
1037 assign a name internally for GDB to display.
1040 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1041 has been integrated into GDB.
1045 ** The function gdb.Write now accepts an optional keyword 'stream'.
1046 This keyword, when provided, will direct the output to either
1047 stdout, stderr, or GDB's logging output.
1049 ** Parameters can now be be sub-classed in Python, and in particular
1050 you may implement the get_set_doc and get_show_doc functions.
1051 This improves how Parameter set/show documentation is processed
1052 and allows for more dynamic content.
1054 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1055 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1056 have an is_valid method.
1058 ** Breakpoints can now be sub-classed in Python, and in particular
1059 you may implement a 'stop' function that is executed each time
1060 the inferior reaches that breakpoint.
1062 ** New function gdb.lookup_global_symbol looks up a global symbol.
1064 ** GDB values in Python are now callable if the value represents a
1065 function. For example, if 'some_value' represents a function that
1066 takes two integer parameters and returns a value, you can call
1067 that function like so:
1069 result = some_value (10,20)
1071 ** Module gdb.types has been added.
1072 It contains a collection of utilities for working with gdb.Types objects:
1073 get_basic_type, has_field, make_enum_dict.
1075 ** Module gdb.printing has been added.
1076 It contains utilities for writing and registering pretty-printers.
1077 New classes: PrettyPrinter, SubPrettyPrinter,
1078 RegexpCollectionPrettyPrinter.
1079 New function: register_pretty_printer.
1081 ** New commands "info pretty-printers", "enable pretty-printer" and
1082 "disable pretty-printer" have been added.
1084 ** gdb.parameter("directories") is now available.
1086 ** New function gdb.newest_frame returns the newest frame in the
1089 ** The gdb.InferiorThread class has a new "name" attribute. This
1090 holds the thread's name.
1092 ** Python Support for Inferior events.
1093 Python scripts can add observers to be notified of events
1094 occurring in the process being debugged.
1095 The following events are currently supported:
1096 - gdb.events.cont Continue event.
1097 - gdb.events.exited Inferior exited event.
1098 - gdb.events.stop Signal received, and Breakpoint hit events.
1102 ** GDB now puts template parameters in scope when debugging in an
1103 instantiation. For example, if you have:
1105 template<int X> int func (void) { return X; }
1107 then if you step into func<5>, "print X" will show "5". This
1108 feature requires proper debuginfo support from the compiler; it
1109 was added to GCC 4.5.
1111 ** The motion commands "next", "finish", "until", and "advance" now
1112 work better when exceptions are thrown. In particular, GDB will
1113 no longer lose control of the inferior; instead, the GDB will
1114 stop the inferior at the point at which the exception is caught.
1115 This functionality requires a change in the exception handling
1116 code that was introduced in GCC 4.5.
1118 * GDB now follows GCC's rules on accessing volatile objects when
1119 reading or writing target state during expression evaluation.
1120 One notable difference to prior behavior is that "print x = 0"
1121 no longer generates a read of x; the value of the assignment is
1122 now always taken directly from the value being assigned.
1124 * GDB now has some support for using labels in the program's source in
1125 linespecs. For instance, you can use "advance label" to continue
1126 execution to a label.
1128 * GDB now has support for reading and writing a new .gdb_index
1129 section. This section holds a fast index of DWARF debugging
1130 information and can be used to greatly speed up GDB startup and
1131 operation. See the documentation for `save gdb-index' for details.
1133 * The "watch" command now accepts an optional "-location" argument.
1134 When used, this causes GDB to watch the memory referred to by the
1135 expression. Such a watchpoint is never deleted due to it going out
1138 * GDB now supports thread debugging of core dumps on GNU/Linux.
1140 GDB now activates thread debugging using the libthread_db library
1141 when debugging GNU/Linux core dumps, similarly to when debugging
1142 live processes. As a result, when debugging a core dump file, GDB
1143 is now able to display pthread_t ids of threads. For example, "info
1144 threads" shows the same output as when debugging the process when it
1145 was live. In earlier releases, you'd see something like this:
1148 * 1 LWP 6780 main () at main.c:10
1150 While now you see this:
1153 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1155 It is also now possible to inspect TLS variables when debugging core
1158 When debugging a core dump generated on a machine other than the one
1159 used to run GDB, you may need to point GDB at the correct
1160 libthread_db library with the "set libthread-db-search-path"
1161 command. See the user manual for more details on this command.
1163 * When natively debugging programs on PowerPC BookE processors running
1164 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1165 which stop execution of the inferior whenever it executes an instruction
1166 at any address within the specified range. See the "PowerPC Embedded"
1167 section in the user manual for more details.
1169 * New features in the GDB remote stub, GDBserver
1171 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1172 and i686 LynxOS (version 5.x).
1174 ** GDBserver is now supported on Blackfin Linux.
1176 * New native configurations
1178 ia64 HP-UX ia64-*-hpux*
1182 Analog Devices, Inc. Blackfin Processor bfin-*
1184 * Ada task switching is now supported on sparc-elf targets when
1185 debugging a program using the Ravenscar Profile. For more information,
1186 see the "Tasking Support when using the Ravenscar Profile" section
1187 in the GDB user manual.
1189 * Guile support was removed.
1191 * New features in the GNU simulator
1193 ** The --map-info flag lists all known core mappings.
1195 ** CFI flashes may be simulated via the "cfi" device.
1197 *** Changes in GDB 7.2
1199 * Shared library support for remote targets by default
1201 When GDB is configured for a generic, non-OS specific target, like
1202 for example, --target=arm-eabi or one of the many *-*-elf targets,
1203 GDB now queries remote stubs for loaded shared libraries using the
1204 `qXfer:libraries:read' packet. Previously, shared library support
1205 was always disabled for such configurations.
1209 ** Argument Dependent Lookup (ADL)
1211 In C++ ADL lookup directs function search to the namespaces of its
1212 arguments even if the namespace has not been imported.
1222 Here the compiler will search for `foo' in the namespace of 'b'
1223 and find A::foo. GDB now supports this. This construct is commonly
1224 used in the Standard Template Library for operators.
1226 ** Improved User Defined Operator Support
1228 In addition to member operators, GDB now supports lookup of operators
1229 defined in a namespace and imported with a `using' directive, operators
1230 defined in the global scope, operators imported implicitly from an
1231 anonymous namespace, and the ADL operators mentioned in the previous
1233 GDB now also supports proper overload resolution for all the previously
1234 mentioned flavors of operators.
1236 ** static const class members
1238 Printing of static const class members that are initialized in the
1239 class definition has been fixed.
1241 * Windows Thread Information Block access.
1243 On Windows targets, GDB now supports displaying the Windows Thread
1244 Information Block (TIB) structure. This structure is visible either
1245 by using the new command `info w32 thread-information-block' or, by
1246 dereferencing the new convenience variable named `$_tlb', a
1247 thread-specific pointer to the TIB. This feature is also supported
1248 when remote debugging using GDBserver.
1250 * Static tracepoints
1252 Static tracepoints are calls in the user program into a tracing
1253 library. One such library is a port of the LTTng kernel tracer to
1254 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1255 When debugging with GDBserver, GDB now supports combining the GDB
1256 tracepoint machinery with such libraries. For example: the user can
1257 use GDB to probe a static tracepoint marker (a call from the user
1258 program into the tracing library) with the new "strace" command (see
1259 "New commands" below). This creates a "static tracepoint" in the
1260 breakpoint list, that can be manipulated with the same feature set
1261 as fast and regular tracepoints. E.g., collect registers, local and
1262 global variables, collect trace state variables, and define
1263 tracepoint conditions. In addition, the user can collect extra
1264 static tracepoint marker specific data, by collecting the new
1265 $_sdata internal variable. When analyzing the trace buffer, you can
1266 inspect $_sdata like any other variable available to GDB. For more
1267 information, see the "Tracepoints" chapter in GDB user manual. New
1268 remote packets have been defined to support static tracepoints, see
1269 the "New remote packets" section below.
1271 * Better reconstruction of tracepoints after disconnected tracing
1273 GDB will attempt to download the original source form of tracepoint
1274 definitions when starting a trace run, and then will upload these
1275 upon reconnection to the target, resulting in a more accurate
1276 reconstruction of the tracepoints that are in use on the target.
1280 You can now exercise direct control over the ways that GDB can
1281 affect your program. For instance, you can disallow the setting of
1282 breakpoints, so that the program can run continuously (assuming
1283 non-stop mode). In addition, the "observer" variable is available
1284 to switch all of the different controls; in observer mode, GDB
1285 cannot affect the target's behavior at all, which is useful for
1286 tasks like diagnosing live systems in the field.
1288 * The new convenience variable $_thread holds the number of the
1291 * New remote packets
1295 Return the address of the Windows Thread Information Block of a given thread.
1299 In response to several of the tracepoint packets, the target may now
1300 also respond with a number of intermediate `qRelocInsn' request
1301 packets before the final result packet, to have GDB handle
1302 relocating an instruction to execute at a different address. This
1303 is particularly useful for stubs that support fast tracepoints. GDB
1304 reports support for this feature in the qSupported packet.
1308 List static tracepoint markers in the target program.
1312 List static tracepoint markers at a given address in the target
1315 qXfer:statictrace:read
1317 Read the static trace data collected (by a `collect $_sdata'
1318 tracepoint action). The remote stub reports support for this packet
1319 to gdb's qSupported query.
1323 Send the current settings of GDB's permission flags.
1327 Send part of the source (textual) form of a tracepoint definition,
1328 which includes location, conditional, and action list.
1330 * The source command now accepts a -s option to force searching for the
1331 script in the source search path even if the script name specifies
1334 * New features in the GDB remote stub, GDBserver
1336 - GDBserver now support tracepoints (including fast tracepoints, and
1337 static tracepoints). The feature is currently supported by the
1338 i386-linux and amd64-linux builds. See the "Tracepoints support
1339 in gdbserver" section in the manual for more information.
1341 GDBserver JIT compiles the tracepoint's conditional agent
1342 expression bytecode into native code whenever possible for low
1343 overhead dynamic tracepoints conditionals. For such tracepoints,
1344 an expression that examines program state is evaluated when the
1345 tracepoint is reached, in order to determine whether to capture
1346 trace data. If the condition is simple and false, processing the
1347 tracepoint finishes very quickly and no data is gathered.
1349 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1350 for static tracepoints support.
1352 - GDBserver now supports x86_64 Windows 64-bit debugging.
1354 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1355 it understands register description.
1357 * The --batch flag now disables pagination and queries.
1359 * X86 general purpose registers
1361 GDB now supports reading/writing byte, word and double-word x86
1362 general purpose registers directly. This means you can use, say,
1363 $ah or $ax to refer, respectively, to the byte register AH and
1364 16-bit word register AX that are actually portions of the 32-bit
1365 register EAX or 64-bit register RAX.
1367 * The `commands' command now accepts a range of breakpoints to modify.
1368 A plain `commands' following a command that creates multiple
1369 breakpoints affects all the breakpoints set by that command. This
1370 applies to breakpoints set by `rbreak', and also applies when a
1371 single `break' command creates multiple breakpoints (e.g.,
1372 breakpoints on overloaded c++ functions).
1374 * The `rbreak' command now accepts a filename specification as part of
1375 its argument, limiting the functions selected by the regex to those
1376 in the specified file.
1378 * Support for remote debugging Windows and SymbianOS shared libraries
1379 from Unix hosts has been improved. Non Windows GDB builds now can
1380 understand target reported file names that follow MS-DOS based file
1381 system semantics, such as file names that include drive letters and
1382 use the backslash character as directory separator. This makes it
1383 possible to transparently use the "set sysroot" and "set
1384 solib-search-path" on Unix hosts to point as host copies of the
1385 target's shared libraries. See the new command "set
1386 target-file-system-kind" described below, and the "Commands to
1387 specify files" section in the user manual for more information.
1391 eval template, expressions...
1392 Convert the values of one or more expressions under the control
1393 of the string template to a command line, and call it.
1395 set target-file-system-kind unix|dos-based|auto
1396 show target-file-system-kind
1397 Set or show the assumed file system kind for target reported file
1400 save breakpoints <filename>
1401 Save all current breakpoint definitions to a file suitable for use
1402 in a later debugging session. To read the saved breakpoint
1403 definitions, use the `source' command.
1405 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1408 info static-tracepoint-markers
1409 Display information about static tracepoint markers in the target.
1411 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1412 Define a static tracepoint by probing a marker at the given
1413 function, line, address, or marker ID.
1417 Enable and disable observer mode.
1419 set may-write-registers on|off
1420 set may-write-memory on|off
1421 set may-insert-breakpoints on|off
1422 set may-insert-tracepoints on|off
1423 set may-insert-fast-tracepoints on|off
1424 set may-interrupt on|off
1425 Set individual permissions for GDB effects on the target. Note that
1426 some of these settings can have undesirable or surprising
1427 consequences, particularly when changed in the middle of a session.
1428 For instance, disabling the writing of memory can prevent
1429 breakpoints from being inserted, cause single-stepping to fail, or
1430 even crash your program, if you disable after breakpoints have been
1431 inserted. However, GDB should not crash.
1433 set record memory-query on|off
1434 show record memory-query
1435 Control whether to stop the inferior if memory changes caused
1436 by an instruction cannot be recorded.
1441 The disassemble command now supports "start,+length" form of two arguments.
1445 ** GDB now provides a new directory location, called the python directory,
1446 where Python scripts written for GDB can be installed. The location
1447 of that directory is <data-directory>/python, where <data-directory>
1448 is the GDB data directory. For more details, see section `Scripting
1449 GDB using Python' in the manual.
1451 ** The GDB Python API now has access to breakpoints, symbols, symbol
1452 tables, program spaces, inferiors, threads and frame's code blocks.
1453 Additionally, GDB Parameters can now be created from the API, and
1454 manipulated via set/show in the CLI.
1456 ** New functions gdb.target_charset, gdb.target_wide_charset,
1457 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1459 ** New exception gdb.GdbError.
1461 ** Pretty-printers are now also looked up in the current program space.
1463 ** Pretty-printers can now be individually enabled and disabled.
1465 ** GDB now looks for names of Python scripts to auto-load in a
1466 special section named `.debug_gdb_scripts', in addition to looking
1467 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1469 * Tracepoint actions were unified with breakpoint commands. In particular,
1470 there are no longer differences in "info break" output for breakpoints and
1471 tracepoints and the "commands" command can be used for both tracepoints and
1472 regular breakpoints.
1476 ARM Symbian arm*-*-symbianelf*
1478 * D language support.
1479 GDB now supports debugging programs written in the D programming
1482 * GDB now supports the extended ptrace interface for PowerPC which is
1483 available since Linux kernel version 2.6.34. This automatically enables
1484 any hardware breakpoints and additional hardware watchpoints available in
1485 the processor. The old ptrace interface exposes just one hardware
1486 watchpoint and no hardware breakpoints.
1488 * GDB is now able to use the Data Value Compare (DVC) register available on
1489 embedded PowerPC processors to implement in hardware simple watchpoint
1490 conditions of the form:
1492 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1494 This works in native GDB running on Linux kernels with the extended ptrace
1495 interface mentioned above.
1497 *** Changes in GDB 7.1
1501 ** Namespace Support
1503 GDB now supports importing of namespaces in C++. This enables the
1504 user to inspect variables from imported namespaces. Support for
1505 namepace aliasing has also been added. So, if a namespace is
1506 aliased in the current scope (e.g. namepace C=A; ) the user can
1507 print variables using the alias (e.g. (gdb) print C::x).
1511 All known bugs relating to the printing of virtual base class were
1512 fixed. It is now possible to call overloaded static methods using a
1517 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1518 and reinterpret_cast<> are now handled by the C++ expression parser.
1522 Xilinx MicroBlaze microblaze-*-*
1527 Xilinx MicroBlaze microblaze
1530 * Multi-program debugging.
1532 GDB now has support for multi-program (a.k.a. multi-executable or
1533 multi-exec) debugging. This allows for debugging multiple inferiors
1534 simultaneously each running a different program under the same GDB
1535 session. See "Debugging Multiple Inferiors and Programs" in the
1536 manual for more information. This implied some user visible changes
1537 in the multi-inferior support. For example, "info inferiors" now
1538 lists inferiors that are not running yet or that have exited
1539 already. See also "New commands" and "New options" below.
1541 * New tracing features
1543 GDB's tracepoint facility now includes several new features:
1545 ** Trace state variables
1547 GDB tracepoints now include support for trace state variables, which
1548 are variables managed by the target agent during a tracing
1549 experiment. They are useful for tracepoints that trigger each
1550 other, so for instance one tracepoint can count hits in a variable,
1551 and then a second tracepoint has a condition that is true when the
1552 count reaches a particular value. Trace state variables share the
1553 $-syntax of GDB convenience variables, and can appear in both
1554 tracepoint actions and condition expressions. Use the "tvariable"
1555 command to create, and "info tvariables" to view; see "Trace State
1556 Variables" in the manual for more detail.
1560 GDB now includes an option for defining fast tracepoints, which
1561 targets may implement more efficiently, such as by installing a jump
1562 into the target agent rather than a trap instruction. The resulting
1563 speedup can be by two orders of magnitude or more, although the
1564 tradeoff is that some program locations on some target architectures
1565 might not allow fast tracepoint installation, for instance if the
1566 instruction to be replaced is shorter than the jump. To request a
1567 fast tracepoint, use the "ftrace" command, with syntax identical to
1568 the regular trace command.
1570 ** Disconnected tracing
1572 It is now possible to detach GDB from the target while it is running
1573 a trace experiment, then reconnect later to see how the experiment
1574 is going. In addition, a new variable disconnected-tracing lets you
1575 tell the target agent whether to continue running a trace if the
1576 connection is lost unexpectedly.
1580 GDB now has the ability to save the trace buffer into a file, and
1581 then use that file as a target, similarly to you can do with
1582 corefiles. You can select trace frames, print data that was
1583 collected in them, and use tstatus to display the state of the
1584 tracing run at the moment that it was saved. To create a trace
1585 file, use "tsave <filename>", and to use it, do "target tfile
1588 ** Circular trace buffer
1590 You can ask the target agent to handle the trace buffer as a
1591 circular buffer, discarding the oldest trace frames to make room for
1592 newer ones, by setting circular-trace-buffer to on. This feature may
1593 not be available for all target agents.
1598 The disassemble command, when invoked with two arguments, now requires
1599 the arguments to be comma-separated.
1602 The info variables command now displays variable definitions. Files
1603 which only declare a variable are not shown.
1606 The source command is now capable of sourcing Python scripts.
1607 This feature is dependent on the debugger being build with Python
1610 Related to this enhancement is also the introduction of a new command
1611 "set script-extension" (see below).
1613 * New commands (for set/show, see "New options" below)
1615 record save [<FILENAME>]
1616 Save a file (in core file format) containing the process record
1617 execution log for replay debugging at a later time.
1619 record restore <FILENAME>
1620 Restore the process record execution log that was saved at an
1621 earlier time, for replay debugging.
1623 add-inferior [-copies <N>] [-exec <FILENAME>]
1626 clone-inferior [-copies <N>] [ID]
1627 Make a new inferior ready to execute the same program another
1628 inferior has loaded.
1633 maint info program-spaces
1634 List the program spaces loaded into GDB.
1636 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1637 show remote interrupt-sequence
1638 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1639 as the sequence to the remote target in order to interrupt the execution.
1640 Ctrl-C is a default. Some system prefers BREAK which is high level of
1641 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1642 Magic SysRq g. It is BREAK signal and character 'g'.
1644 set remote interrupt-on-connect [on | off]
1645 show remote interrupt-on-connect
1646 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1647 remote target when gdb connects to it. This is needed when you debug
1650 set remotebreak [on | off]
1652 Deprecated. Use "set/show remote interrupt-sequence" instead.
1654 tvariable $NAME [ = EXP ]
1655 Create or modify a trace state variable.
1658 List trace state variables and their values.
1660 delete tvariable $NAME ...
1661 Delete one or more trace state variables.
1664 Evaluate the given expressions without collecting anything into the
1665 trace buffer. (Valid in tracepoint actions only.)
1667 ftrace FN / FILE:LINE / *ADDR
1668 Define a fast tracepoint at the given function, line, or address.
1670 * New expression syntax
1672 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1673 GDB now parses 0b101010 identically with 42.
1677 set follow-exec-mode new|same
1678 show follow-exec-mode
1679 Control whether GDB reuses the same inferior across an exec call or
1680 creates a new one. This is useful to be able to restart the old
1681 executable after the inferior having done an exec call.
1683 set default-collect EXPR, ...
1684 show default-collect
1685 Define a list of expressions to be collected at each tracepoint.
1686 This is a useful way to ensure essential items are not overlooked,
1687 such as registers or a critical global variable.
1689 set disconnected-tracing
1690 show disconnected-tracing
1691 If set to 1, the target is instructed to continue tracing if it
1692 loses its connection to GDB. If 0, the target is to stop tracing
1695 set circular-trace-buffer
1696 show circular-trace-buffer
1697 If set to on, the target is instructed to use a circular trace buffer
1698 and discard the oldest trace frames instead of stopping the trace due
1699 to a full trace buffer. If set to off, the trace stops when the buffer
1700 fills up. Some targets may not support this.
1702 set script-extension off|soft|strict
1703 show script-extension
1704 If set to "off", the debugger does not perform any script language
1705 recognition, and all sourced files are assumed to be GDB scripts.
1706 If set to "soft" (the default), files are sourced according to
1707 filename extension, falling back to GDB scripts if the first
1709 If set to "strict", files are sourced according to filename extension.
1711 set ada trust-PAD-over-XVS on|off
1712 show ada trust-PAD-over-XVS
1713 If off, activate a workaround against a bug in the debugging information
1714 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1715 the GCC sources for more information about the GNAT encoding and
1716 PAD types in particular). It is always safe to set this option to
1717 off, but this introduces a slight performance penalty. The default
1720 * Python API Improvements
1722 ** GDB provides the new class gdb.LazyString. This is useful in
1723 some pretty-printing cases. The new method gdb.Value.lazy_string
1724 provides a simple way to create objects of this type.
1726 ** The fields returned by gdb.Type.fields now have an
1727 `is_base_class' attribute.
1729 ** The new method gdb.Type.range returns the range of an array type.
1731 ** The new method gdb.parse_and_eval can be used to parse and
1732 evaluate an expression.
1734 * New remote packets
1737 Define a trace state variable.
1740 Get the current value of a trace state variable.
1743 Set desired tracing behavior upon disconnection.
1746 Set the trace buffer to be linear or circular.
1749 Get data about the tracepoints currently in use.
1753 Process record now works correctly with hardware watchpoints.
1755 Multiple bug fixes have been made to the mips-irix port, making it
1756 much more reliable. In particular:
1757 - Debugging threaded applications is now possible again. Previously,
1758 GDB would hang while starting the program, or while waiting for
1759 the program to stop at a breakpoint.
1760 - Attaching to a running process no longer hangs.
1761 - An error occurring while loading a core file has been fixed.
1762 - Changing the value of the PC register now works again. This fixes
1763 problems observed when using the "jump" command, or when calling
1764 a function from GDB, or even when assigning a new value to $pc.
1765 - With the "finish" and "return" commands, the return value for functions
1766 returning a small array is now correctly printed.
1767 - It is now possible to break on shared library code which gets executed
1768 during a shared library init phase (code executed while executing
1769 their .init section). Previously, the breakpoint would have no effect.
1770 - GDB is now able to backtrace through the signal handler for
1771 non-threaded programs.
1773 PIE (Position Independent Executable) programs debugging is now supported.
1774 This includes debugging execution of PIC (Position Independent Code) shared
1775 libraries although for that, it should be possible to run such libraries as an
1778 *** Changes in GDB 7.0
1780 * GDB now has an interface for JIT compilation. Applications that
1781 dynamically generate code can create symbol files in memory and register
1782 them with GDB. For users, the feature should work transparently, and
1783 for JIT developers, the interface is documented in the GDB manual in the
1784 "JIT Compilation Interface" chapter.
1786 * Tracepoints may now be conditional. The syntax is as for
1787 breakpoints; either an "if" clause appended to the "trace" command,
1788 or the "condition" command is available. GDB sends the condition to
1789 the target for evaluation using the same bytecode format as is used
1790 for tracepoint actions.
1792 * The disassemble command now supports: an optional /r modifier, print the
1793 raw instructions in hex as well as in symbolic form, and an optional /m
1794 modifier to print mixed source+assembly.
1796 * Process record and replay
1798 In a architecture environment that supports ``process record and
1799 replay'', ``process record and replay'' target can record a log of
1800 the process execution, and replay it with both forward and reverse
1803 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1804 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1805 set execution-direction {forward|reverse}, for targets that support
1808 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1809 feature is available with a native GDB running on kernel version
1812 * GDB now has support for multi-byte and wide character sets on the
1813 target. Strings whose character type is wchar_t, char16_t, or
1814 char32_t are now correctly printed. GDB supports wide- and unicode-
1815 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1816 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1817 `printf'. This feature requires iconv to work properly; if your
1818 system does not have a working iconv, GDB can use GNU libiconv. See
1819 the installation instructions for more information.
1821 * GDB now supports automatic retrieval of shared library files from
1822 remote targets. To use this feature, specify a system root that begins
1823 with the `remote:' prefix, either via the `set sysroot' command or via
1824 the `--with-sysroot' configure-time option.
1826 * "info sharedlibrary" now takes an optional regex of libraries to show,
1827 and it now reports if a shared library has no debugging information.
1829 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1830 now complete on file names.
1832 * When completing in expressions, gdb will attempt to limit
1833 completions to allowable structure or union fields, where appropriate.
1834 For instance, consider:
1836 # struct example { int f1; double f2; };
1837 # struct example variable;
1840 If the user types TAB at the end of this command line, the available
1841 completions will be "f1" and "f2".
1843 * Inlined functions are now supported. They show up in backtraces, and
1844 the "step", "next", and "finish" commands handle them automatically.
1846 * GDB now supports the token-splicing (##) and stringification (#)
1847 operators when expanding macros. It also supports variable-arity
1850 * GDB now supports inspecting extra signal information, exported by
1851 the new $_siginfo convenience variable. The feature is currently
1852 implemented on linux ARM, i386 and amd64.
1854 * GDB can now display the VFP floating point registers and NEON vector
1855 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1856 can provide these registers (requires Linux 2.6.30 or later). Remote
1857 and simulator targets may also provide them.
1859 * New remote packets
1862 Search memory for a sequence of bytes.
1865 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1866 operation over reliable transport links. Use of this packet is
1867 controlled by the `set remote noack-packet' command.
1870 Kill the process with the specified process ID. Use this in preference
1871 to `k' when multiprocess protocol extensions are supported.
1874 Obtains additional operating system information
1878 Read or write additional signal information.
1880 * Removed remote protocol undocumented extension
1882 An undocumented extension to the remote protocol's `S' stop reply
1883 packet that permited the stub to pass a process id was removed.
1884 Remote servers should use the `T' stop reply packet instead.
1886 * GDB now supports multiple function calling conventions according to the
1887 DWARF-2 DW_AT_calling_convention function attribute.
1889 * The SH target utilizes the aforementioned change to distinguish between gcc
1890 and Renesas calling convention. It also adds the new CLI commands
1891 `set/show sh calling-convention'.
1893 * GDB can now read compressed debug sections, as produced by GNU gold
1894 with the --compress-debug-sections=zlib flag.
1896 * 64-bit core files are now supported on AIX.
1898 * Thread switching is now supported on Tru64.
1900 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1901 which will be allocated using malloc later in program execution.
1903 * The qXfer:libraries:read remote procotol packet now allows passing a
1904 list of section offsets.
1906 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1907 conditions handling signals delivered during attach or thread creation
1908 have also been fixed.
1910 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1911 From the user's standpoint, all unqualified instances of True and False
1912 are treated as the standard definitions, regardless of context.
1914 * GDB now parses C++ symbol and type names more flexibly. For
1917 template<typename T> class C { };
1920 GDB will now correctly handle all of:
1922 ptype C<char const *>
1923 ptype C<char const*>
1924 ptype C<const char *>
1925 ptype C<const char*>
1927 * New features in the GDB remote stub, gdbserver
1929 - The "--wrapper" command-line argument tells gdbserver to use a
1930 wrapper program to launch programs for debugging.
1932 - On PowerPC and S/390 targets, it is now possible to use a single
1933 gdbserver executable to debug both 32-bit and 64-bit programs.
1934 (This requires gdbserver itself to be built as a 64-bit executable.)
1936 - gdbserver uses the new noack protocol mode for TCP connections to
1937 reduce communications latency, if also supported and enabled in GDB.
1939 - Support for the sparc64-linux-gnu target is now included in
1942 - The amd64-linux build of gdbserver now supports debugging both
1943 32-bit and 64-bit programs.
1945 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1946 now support hardware watchpoints, and will use them automatically
1951 GDB now has support for scripting using Python. Whether this is
1952 available is determined at configure time.
1954 New GDB commands can now be written in Python.
1956 * Ada tasking support
1958 Ada tasks can now be inspected in GDB. The following commands have
1962 Print the list of Ada tasks.
1964 Print detailed information about task number N.
1966 Print the task number of the current task.
1968 Switch the context of debugging to task number N.
1970 * Support for user-defined prefixed commands. The "define" command can
1971 add new commands to existing prefixes, e.g. "target".
1973 * Multi-inferior, multi-process debugging.
1975 GDB now has generalized support for multi-inferior debugging. See
1976 "Debugging Multiple Inferiors" in the manual for more information.
1977 Although availability still depends on target support, the command
1978 set is more uniform now. The GNU/Linux specific multi-forks support
1979 has been migrated to this new framework. This implied some user
1980 visible changes; see "New commands" and also "Removed commands"
1983 * Target descriptions can now describe the target OS ABI. See the
1984 "Target Description Format" section in the user manual for more
1987 * Target descriptions can now describe "compatible" architectures
1988 to indicate that the target can execute applications for a different
1989 architecture in addition to those for the main target architecture.
1990 See the "Target Description Format" section in the user manual for
1993 * Multi-architecture debugging.
1995 GDB now includes general supports for debugging applications on
1996 hybrid systems that use more than one single processor architecture
1997 at the same time. Each such hybrid architecture still requires
1998 specific support to be added. The only hybrid architecture supported
1999 in this version of GDB is the Cell Broadband Engine.
2001 * GDB now supports integrated debugging of Cell/B.E. applications that
2002 use both the PPU and SPU architectures. To enable support for hybrid
2003 Cell/B.E. debugging, you need to configure GDB to support both the
2004 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2005 --enable-targets configure option.
2007 * Non-stop mode debugging.
2009 For some targets, GDB now supports an optional mode of operation in
2010 which you can examine stopped threads while other threads continue
2011 to execute freely. This is referred to as non-stop mode, with the
2012 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2013 section in the user manual for more information.
2015 To be able to support remote non-stop debugging, a remote stub needs
2016 to implement the non-stop mode remote protocol extensions, as
2017 described in the "Remote Non-Stop" section of the user manual. The
2018 GDB remote stub, gdbserver, has been adjusted to support these
2019 extensions on linux targets.
2021 * New commands (for set/show, see "New options" below)
2023 catch syscall [NAME(S) | NUMBER(S)]
2024 Catch system calls. Arguments, which should be names of system
2025 calls or their numbers, mean catch only those syscalls. Without
2026 arguments, every syscall will be caught. When the inferior issues
2027 any of the specified syscalls, GDB will stop and announce the system
2028 call, both when it is called and when its call returns. This
2029 feature is currently available with a native GDB running on the
2030 Linux Kernel, under the following architectures: x86, x86_64,
2031 PowerPC and PowerPC64.
2033 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2035 Search memory for a sequence of bytes.
2037 maint set python print-stack
2038 maint show python print-stack
2039 Show a stack trace when an error is encountered in a Python script.
2042 Invoke CODE by passing it to the Python interpreter.
2047 These allow macros to be defined, undefined, and listed
2051 Show operating system information about processes.
2054 List the inferiors currently under GDB's control.
2057 Switch focus to inferior number NUM.
2060 Detach from inferior number NUM.
2063 Kill inferior number NUM.
2067 set spu stop-on-load
2068 show spu stop-on-load
2069 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2071 set spu auto-flush-cache
2072 show spu auto-flush-cache
2073 Control whether to automatically flush the software-managed cache
2074 during Cell/B.E. debugging.
2076 set sh calling-convention
2077 show sh calling-convention
2078 Control the calling convention used when calling SH target functions.
2081 show debug timestamp
2082 Control display of timestamps with GDB debugging output.
2084 set disassemble-next-line
2085 show disassemble-next-line
2086 Control display of disassembled source lines or instructions when
2089 set remote noack-packet
2090 show remote noack-packet
2091 Set/show the use of remote protocol QStartNoAckMode packet. See above
2092 under "New remote packets."
2094 set remote query-attached-packet
2095 show remote query-attached-packet
2096 Control use of remote protocol `qAttached' (query-attached) packet.
2098 set remote read-siginfo-object
2099 show remote read-siginfo-object
2100 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2103 set remote write-siginfo-object
2104 show remote write-siginfo-object
2105 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2108 set remote reverse-continue
2109 show remote reverse-continue
2110 Control use of remote protocol 'bc' (reverse-continue) packet.
2112 set remote reverse-step
2113 show remote reverse-step
2114 Control use of remote protocol 'bs' (reverse-step) packet.
2116 set displaced-stepping
2117 show displaced-stepping
2118 Control displaced stepping mode. Displaced stepping is a way to
2119 single-step over breakpoints without removing them from the debuggee.
2120 Also known as "out-of-line single-stepping".
2123 show debug displaced
2124 Control display of debugging info for displaced stepping.
2126 maint set internal-error
2127 maint show internal-error
2128 Control what GDB does when an internal error is detected.
2130 maint set internal-warning
2131 maint show internal-warning
2132 Control what GDB does when an internal warning is detected.
2137 Use a wrapper program to launch programs for debugging.
2139 set multiple-symbols (all|ask|cancel)
2140 show multiple-symbols
2141 The value of this variable can be changed to adjust the debugger behavior
2142 when an expression or a breakpoint location contains an ambiguous symbol
2143 name (an overloaded function name, for instance).
2145 set breakpoint always-inserted
2146 show breakpoint always-inserted
2147 Keep breakpoints always inserted in the target, as opposed to inserting
2148 them when resuming the target, and removing them when the target stops.
2149 This option can improve debugger performance on slow remote targets.
2151 set arm fallback-mode (arm|thumb|auto)
2152 show arm fallback-mode
2153 set arm force-mode (arm|thumb|auto)
2155 These commands control how ARM GDB determines whether instructions
2156 are ARM or Thumb. The default for both settings is auto, which uses
2157 the current CPSR value for instructions without symbols; previous
2158 versions of GDB behaved as if "set arm fallback-mode arm".
2160 set disable-randomization
2161 show disable-randomization
2162 Standalone programs run with the virtual address space randomization enabled
2163 by default on some platforms. This option keeps the addresses stable across
2164 multiple debugging sessions.
2168 Control whether other threads are stopped or not when some thread hits
2173 Requests that asynchronous execution is enabled in the target, if available.
2174 In this case, it's possible to resume target in the background, and interact
2175 with GDB while the target is running. "show target-async" displays the
2176 current state of asynchronous execution of the target.
2178 set target-wide-charset
2179 show target-wide-charset
2180 The target-wide-charset is the name of the character set that GDB
2181 uses when printing characters whose type is wchar_t.
2183 set tcp auto-retry (on|off)
2185 set tcp connect-timeout
2186 show tcp connect-timeout
2187 These commands allow GDB to retry failed TCP connections to a remote stub
2188 with a specified timeout period; this is useful if the stub is launched
2189 in parallel with GDB but may not be ready to accept connections immediately.
2191 set libthread-db-search-path
2192 show libthread-db-search-path
2193 Control list of directories which GDB will search for appropriate
2196 set schedule-multiple (on|off)
2197 show schedule-multiple
2198 Allow GDB to resume all threads of all processes or only threads of
2199 the current process.
2203 Use more aggressive caching for accesses to the stack. This improves
2204 performance of remote debugging (particularly backtraces) without
2205 affecting correctness.
2207 set interactive-mode (on|off|auto)
2208 show interactive-mode
2209 Control whether GDB runs in interactive mode (on) or not (off).
2210 When in interactive mode, GDB waits for the user to answer all
2211 queries. Otherwise, GDB does not wait and assumes the default
2212 answer. When set to auto (the default), GDB determines which
2213 mode to use based on the stdin settings.
2218 For program forks, this is replaced by the new more generic `info
2219 inferiors' command. To list checkpoints, you can still use the
2220 `info checkpoints' command, which was an alias for the `info forks'
2224 Replaced by the new `inferior' command. To switch between
2225 checkpoints, you can still use the `restart' command, which was an
2226 alias for the `fork' command.
2229 This is removed, since some targets don't have a notion of
2230 processes. To switch between processes, you can still use the
2231 `inferior' command using GDB's own inferior number.
2234 For program forks, this is replaced by the new more generic `kill
2235 inferior' command. To delete a checkpoint, you can still use the
2236 `delete checkpoint' command, which was an alias for the `delete
2240 For program forks, this is replaced by the new more generic `detach
2241 inferior' command. To detach a checkpoint, you can still use the
2242 `detach checkpoint' command, which was an alias for the `detach
2245 * New native configurations
2247 x86/x86_64 Darwin i[34567]86-*-darwin*
2249 x86_64 MinGW x86_64-*-mingw*
2253 Lattice Mico32 lm32-*
2254 x86 DICOS i[34567]86-*-dicos*
2255 x86_64 DICOS x86_64-*-dicos*
2258 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2259 (mingw32ce) debugging.
2265 These commands were actually not implemented on any target.
2267 *** Changes in GDB 6.8
2269 * New native configurations
2271 NetBSD/hppa hppa*-*netbsd*
2272 Xtensa GNU/Linux xtensa*-*-linux*
2276 NetBSD/hppa hppa*-*-netbsd*
2277 Xtensa GNU/Lunux xtensa*-*-linux*
2279 * Change in command line behavior -- corefiles vs. process ids.
2281 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2282 attaching to process NUMBER fails, GDB no longer attempts to open a
2283 core file named NUMBER. Attaching to a program using the -c option
2284 is no longer supported. Instead, use the '-p' or '--pid' options.
2286 * GDB can now be built as a native debugger for debugging Windows x86
2287 (mingw32) Portable Executable (PE) programs.
2289 * Pending breakpoints no longer change their number when their address
2292 * GDB now supports breakpoints with multiple locations,
2293 including breakpoints on C++ constructors, inside C++ templates,
2294 and in inlined functions.
2296 * GDB's ability to debug optimized code has been improved. GDB more
2297 accurately identifies function bodies and lexical blocks that occupy
2298 more than one contiguous range of addresses.
2300 * Target descriptions can now describe registers for PowerPC.
2302 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2303 registers on PowerPC targets.
2305 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2306 targets even when the libthread_db library is not available.
2308 * The GDB remote stub, gdbserver, now supports the new file transfer
2309 commands (remote put, remote get, and remote delete).
2311 * The GDB remote stub, gdbserver, now supports run and attach in
2312 extended-remote mode.
2314 * hppa*64*-*-hpux11* target broken
2315 The debugger is unable to start a program and fails with the following
2316 error: "Error trying to get information about dynamic linker".
2317 The gdb-6.7 release is also affected.
2319 * GDB now supports the --enable-targets= configure option to allow
2320 building a single GDB executable that supports multiple remote
2321 target architectures.
2323 * GDB now supports debugging C and C++ programs which use the
2324 Decimal Floating Point extension. In addition, the PowerPC target
2325 now has a set of pseudo-registers to inspect decimal float values
2326 stored in two consecutive float registers.
2328 * The -break-insert MI command can optionally create pending
2331 * Improved support for debugging Ada
2332 Many improvements to the Ada language support have been made. These
2334 - Better support for Ada2005 interface types
2335 - Improved handling of arrays and slices in general
2336 - Better support for Taft-amendment types
2337 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2339 - Improved command completion in Ada
2342 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2347 set print frame-arguments (all|scalars|none)
2348 show print frame-arguments
2349 The value of this variable can be changed to control which argument
2350 values should be printed by the debugger when displaying a frame.
2355 Transfer files to and from a remote target, and delete remote files.
2362 Transfer files to and from a remote target, and delete remote files.
2364 * New remote packets
2371 Open, close, read, write, and delete files on the remote system.
2374 Attach to an existing process on the remote system, in extended-remote
2378 Run a new process on the remote system, in extended-remote mode.
2380 *** Changes in GDB 6.7
2382 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2383 bfd, libiberty and opcodes, as revealed by static analysis donated by
2384 Coverity, Inc. (http://scan.coverity.com).
2386 * When looking up multiply-defined global symbols, GDB will now prefer the
2387 symbol definition in the current shared library if it was built using the
2388 -Bsymbolic linker option.
2390 * When the Text User Interface (TUI) is not configured, GDB will now
2391 recognize the -tui command-line option and print a message that the TUI
2394 * The GDB remote stub, gdbserver, now has lower overhead for high
2395 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2397 * GDB for MIPS targets now autodetects whether a remote target provides
2398 32-bit or 64-bit register values.
2400 * Support for C++ member pointers has been improved.
2402 * GDB now understands XML target descriptions, which specify the
2403 target's overall architecture. GDB can read a description from
2404 a local file or over the remote serial protocol.
2406 * Vectors of single-byte data use a new integer type which is not
2407 automatically displayed as character or string data.
2409 * The /s format now works with the print command. It displays
2410 arrays of single-byte integers and pointers to single-byte integers
2413 * Target descriptions can now describe target-specific registers,
2414 for architectures which have implemented the support (currently
2415 only ARM, M68K, and MIPS).
2417 * GDB and the GDB remote stub, gdbserver, now support the XScale
2420 * The GDB remote stub, gdbserver, has been updated to support
2421 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2422 has been rewritten to use the standard GDB remote protocol.
2424 * GDB can now step into C++ functions which are called through thunks.
2426 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2428 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2429 layout. It also supports a TextSeg= and DataSeg= response when only
2430 segment base addresses (rather than offsets) are available.
2432 * The /i format now outputs any trailing branch delay slot instructions
2433 immediately following the last instruction within the count specified.
2435 * The GDB remote protocol "T" stop reply packet now supports a
2436 "library" response. Combined with the new "qXfer:libraries:read"
2437 packet, this response allows GDB to debug shared libraries on targets
2438 where the operating system manages the list of loaded libraries (e.g.
2439 Windows and SymbianOS).
2441 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2442 (DLLs) on Windows and Windows CE targets.
2444 * GDB now supports a faster verification that a .debug file matches its binary
2445 according to its build-id signature, if the signature is present.
2451 Enable or disable hardware flow control (RTS/CTS) on the serial port
2452 when debugging using remote targets.
2454 set mem inaccessible-by-default
2455 show mem inaccessible-by-default
2456 If the target supplies a memory map, for instance via the remote
2457 protocol's "qXfer:memory-map:read" packet, setting this variable
2458 prevents GDB from accessing memory outside the memory map. This
2459 is useful for targets with memory mapped registers or which react
2460 badly to accesses of unmapped address space.
2462 set breakpoint auto-hw
2463 show breakpoint auto-hw
2464 If the target supplies a memory map, for instance via the remote
2465 protocol's "qXfer:memory-map:read" packet, setting this variable
2466 lets GDB use hardware breakpoints automatically for memory regions
2467 where it can not use software breakpoints. This covers both the
2468 "break" command and internal breakpoints used for other commands
2469 including "next" and "finish".
2472 catch exception unhandled
2473 Stop the program execution when Ada exceptions are raised.
2476 Stop the program execution when an Ada assertion failed.
2480 Set an alternate system root for target files. This is a more
2481 general version of "set solib-absolute-prefix", which is now
2482 an alias to "set sysroot".
2485 Provide extended SPU facility status information. This set of
2486 commands is available only when debugging the Cell/B.E. SPU
2489 * New native configurations
2491 OpenBSD/sh sh*-*openbsd*
2494 unset tdesc filename
2496 Use the specified local file as an XML target description, and do
2497 not query the target for its built-in description.
2501 OpenBSD/sh sh*-*-openbsd*
2502 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2503 Toshiba Media Processor mep-elf
2505 * New remote packets
2508 Ignore the specified signals; pass them directly to the debugged program
2509 without stopping other threads or reporting them to GDB.
2511 qXfer:features:read:
2512 Read an XML target description from the target, which describes its
2517 Read or write contents of an spufs file on the target system. These
2518 packets are available only on the Cell/B.E. SPU architecture.
2520 qXfer:libraries:read:
2521 Report the loaded shared libraries. Combined with new "T" packet
2522 response, this packet allows GDB to debug shared libraries on
2523 targets where the operating system manages the list of loaded
2524 libraries (e.g. Windows and SymbianOS).
2528 Support for these obsolete configurations has been removed.
2536 i[34567]86-*-lynxos*
2537 i[34567]86-*-netware*
2538 i[34567]86-*-sco3.2v5*
2539 i[34567]86-*-sco3.2v4*
2541 i[34567]86-*-sysv4.2*
2544 i[34567]86-*-unixware2*
2545 i[34567]86-*-unixware*
2554 * Other removed features
2561 Various m68k-only ROM monitors.
2568 Various Renesas ROM monitors and debugging interfaces for SH and
2573 Support for a Macraigor serial interface to on-chip debugging.
2574 GDB does not directly support the newer parallel or USB
2579 A debug information format. The predecessor to DWARF 2 and
2580 DWARF 3, which are still supported.
2582 Support for the HP aCC compiler on HP-UX/PA-RISC
2584 SOM-encapsulated symbolic debugging information, automatic
2585 invocation of pxdb, and the aCC custom C++ ABI. This does not
2586 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2587 with aCC can still be debugged on an assembly level.
2589 MIPS ".pdr" sections
2591 A MIPS-specific format used to describe stack frame layout
2592 in debugging information.
2596 GDB could work with an older version of Guile to debug
2597 the interpreter and Scheme programs running in it.
2599 set mips stack-arg-size
2600 set mips saved-gpreg-size
2602 Use "set mips abi" to control parameter passing for MIPS.
2604 *** Changes in GDB 6.6
2609 Cell Broadband Engine SPU spu-elf
2611 * GDB can now be configured as a cross-debugger targeting native Windows
2612 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2613 running on a Windows system over TCP/IP to debug Windows programs.
2615 * The GDB remote stub, gdbserver, has been updated to support Windows and
2616 Cygwin debugging. Both single-threaded and multi-threaded programs are
2619 * The "set trust-readonly-sections" command works again. This command was
2620 broken in GDB 6.3, 6.4, and 6.5.
2622 * The "load" command now supports writing to flash memory, if the remote
2623 stub provides the required support.
2625 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2626 longer requires symbolic debug information (e.g. DWARF-2).
2631 unset substitute-path
2632 show substitute-path
2633 Manage a list of substitution rules that GDB uses to rewrite the name
2634 of the directories where the sources are located. This can be useful
2635 for instance when the sources were moved to a different location
2636 between compilation and debugging.
2640 Print each CLI command as it is executed. Each command is prefixed with
2641 a number of `+' symbols representing the nesting depth.
2642 The source command now has a `-v' option to enable the same feature.
2646 The ARM Demon monitor support (RDP protocol, "target rdp").
2648 Kernel Object Display, an embedded debugging feature which only worked with
2649 an obsolete version of Cisco IOS.
2651 The 'set download-write-size' and 'show download-write-size' commands.
2653 * New remote packets
2656 Tell a stub about GDB client features, and request remote target features.
2657 The first feature implemented is PacketSize, which allows the target to
2658 specify the size of packets it can handle - to minimize the number of
2659 packets required and improve performance when connected to a remote
2663 Fetch an OS auxilliary vector from the remote stub. This packet is a
2664 more efficient replacement for qPart:auxv:read.
2666 qXfer:memory-map:read:
2667 Fetch a memory map from the remote stub, including information about
2668 RAM, ROM, and flash memory devices.
2673 Erase and program a flash memory device.
2675 * Removed remote packets
2678 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2679 used it, and only gdbserver implemented it.
2681 *** Changes in GDB 6.5
2685 Renesas M32C/M16C m32c-elf
2687 Morpho Technologies ms1 ms1-elf
2691 init-if-undefined Initialize a convenience variable, but
2692 only if it doesn't already have a value.
2694 The following commands are presently only implemented for native GNU/Linux:
2696 checkpoint Save a snapshot of the program state.
2698 restart <n> Return the program state to a
2699 previously saved state.
2701 info checkpoints List currently saved checkpoints.
2703 delete-checkpoint <n> Delete a previously saved checkpoint.
2705 set|show detach-on-fork Tell gdb whether to detach from a newly
2706 forked process, or to keep debugging it.
2708 info forks List forks of the user program that
2709 are available to be debugged.
2711 fork <n> Switch to debugging one of several
2712 forks of the user program that are
2713 available to be debugged.
2715 delete-fork <n> Delete a fork from the list of forks
2716 that are available to be debugged (and
2717 kill the forked process).
2719 detach-fork <n> Delete a fork from the list of forks
2720 that are available to be debugged (and
2721 allow the process to continue).
2725 Morpho Technologies ms2 ms1-elf
2727 * Improved Windows host support
2729 GDB now builds as a cross debugger hosted on i686-mingw32, including
2730 native console support, and remote communications using either
2731 network sockets or serial ports.
2733 * Improved Modula-2 language support
2735 GDB can now print most types in the Modula-2 syntax. This includes:
2736 basic types, set types, record types, enumerated types, range types,
2737 pointer types and ARRAY types. Procedure var parameters are correctly
2738 printed and hexadecimal addresses and character constants are also
2739 written in the Modula-2 syntax. Best results can be obtained by using
2740 GNU Modula-2 together with the -gdwarf-2 command line option.
2744 The ARM rdi-share module.
2746 The Netware NLM debug server.
2748 *** Changes in GDB 6.4
2750 * New native configurations
2752 OpenBSD/arm arm*-*-openbsd*
2753 OpenBSD/mips64 mips64-*-openbsd*
2757 Morpho Technologies ms1 ms1-elf
2759 * New command line options
2761 --batch-silent As for --batch, but totally silent.
2762 --return-child-result The debugger will exist with the same value
2763 the child (debugged) program exited with.
2764 --eval-command COMMAND, -ex COMMAND
2765 Execute a single GDB CLI command. This may be
2766 specified multiple times and in conjunction
2767 with the --command (-x) option.
2769 * Deprecated commands removed
2771 The following commands, that were deprecated in 2000, have been
2775 set|show arm disassembly-flavor set|show arm disassembler
2776 othernames set arm disassembler
2777 set|show remotedebug set|show debug remote
2778 set|show archdebug set|show debug arch
2779 set|show eventdebug set|show debug event
2782 * New BSD user-level threads support
2784 It is now possible to debug programs using the user-level threads
2785 library on OpenBSD and FreeBSD. Currently supported (target)
2788 FreeBSD/amd64 x86_64-*-freebsd*
2789 FreeBSD/i386 i386-*-freebsd*
2790 OpenBSD/i386 i386-*-openbsd*
2792 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2793 are not yet supported.
2795 * New support for Matsushita MN10300 w/sim added
2796 (Work in progress). mn10300-elf.
2798 * REMOVED configurations and files
2800 VxWorks and the XDR protocol *-*-vxworks
2801 Motorola MCORE mcore-*-*
2802 National Semiconductor NS32000 ns32k-*-*
2804 * New "set print array-indexes" command
2806 After turning this setting "on", GDB prints the index of each element
2807 when displaying arrays. The default is "off" to preserve the previous
2810 * VAX floating point support
2812 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2814 * User-defined command support
2816 In addition to using $arg0..$arg9 for argument passing, it is now possible
2817 to use $argc to determine now many arguments have been passed. See the
2818 section on user-defined commands in the user manual for more information.
2820 *** Changes in GDB 6.3:
2822 * New command line option
2824 GDB now accepts -l followed by a number to set the timeout for remote
2827 * GDB works with GCC -feliminate-dwarf2-dups
2829 GDB now supports a more compact representation of DWARF-2 debug
2830 information using DW_FORM_ref_addr references. These are produced
2831 by GCC with the option -feliminate-dwarf2-dups and also by some
2832 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2833 to use -feliminate-dwarf2-dups.
2835 * Internationalization
2837 When supported by the host system, GDB will be built with
2838 internationalization (libintl). The task of marking up the sources is
2839 continued, we're looking forward to our first translation.
2843 Initial support for debugging programs compiled with the GNAT
2844 implementation of the Ada programming language has been integrated
2845 into GDB. In this release, support is limited to expression evaluation.
2847 * New native configurations
2849 GNU/Linux/m32r m32r-*-linux-gnu
2853 GDB's remote protocol now includes support for the 'p' packet. This
2854 packet is used to fetch individual registers from a remote inferior.
2856 * END-OF-LIFE registers[] compatibility module
2858 GDB's internal register infrastructure has been completely rewritten.
2859 The new infrastructure making possible the implementation of key new
2860 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2863 GDB 6.3 will be the last release to include the the registers[]
2864 compatibility module that allowed out-of-date configurations to
2865 continue to work. This change directly impacts the following
2875 powerpc bdm protocol
2877 Unless there is activity to revive these configurations, they will be
2878 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2880 * OBSOLETE configurations and files
2882 Configurations that have been declared obsolete in this release have
2883 been commented out. Unless there is activity to revive these
2884 configurations, the next release of GDB will have their sources
2885 permanently REMOVED.
2894 *** Changes in GDB 6.2.1:
2896 * MIPS `break main; run' gave an heuristic-fence-post warning
2898 When attempting to run even a simple program, a warning about
2899 heuristic-fence-post being hit would be reported. This problem has
2902 * MIPS IRIX 'long double' crashed GDB
2904 When examining a long double variable, GDB would get a segmentation
2905 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2906 IRIX long double values).
2910 A bug in the VAX stack code was causing problems with the "next"
2911 command. This problem has been fixed.
2913 *** Changes in GDB 6.2:
2915 * Fix for ``many threads''
2917 On GNU/Linux systems that use the NPTL threads library, a program
2918 rapidly creating and deleting threads would confuse GDB leading to the
2921 ptrace: No such process.
2922 thread_db_get_info: cannot get thread info: generic error
2924 This problem has been fixed.
2926 * "-async" and "-noasync" options removed.
2928 Support for the broken "-noasync" option has been removed (it caused
2931 * New ``start'' command.
2933 This command runs the program until the begining of the main procedure.
2935 * New BSD Kernel Data Access Library (libkvm) interface
2937 Using ``target kvm'' it is now possible to debug kernel core dumps and
2938 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2939 platforms. Currently supported (native-only) configurations are:
2941 FreeBSD/amd64 x86_64-*-freebsd*
2942 FreeBSD/i386 i?86-*-freebsd*
2943 NetBSD/i386 i?86-*-netbsd*
2944 NetBSD/m68k m68*-*-netbsd*
2945 NetBSD/sparc sparc-*-netbsd*
2946 OpenBSD/amd64 x86_64-*-openbsd*
2947 OpenBSD/i386 i?86-*-openbsd*
2948 OpenBSD/m68k m68*-openbsd*
2949 OpenBSD/sparc sparc-*-openbsd*
2951 * Signal trampoline code overhauled
2953 Many generic problems with GDB's signal handling code have been fixed.
2954 These include: backtraces through non-contiguous stacks; recognition
2955 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2956 call; backtrace through a signal trampoline; step into and out of
2957 signal handlers; and single-stepping in the signal trampoline.
2959 Please note that kernel bugs are a limiting factor here. These
2960 features have been shown to work on an s390 GNU/Linux system that
2961 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2963 * Cygwin support for DWARF 2 added.
2965 * New native configurations
2967 GNU/Linux/hppa hppa*-*-linux*
2968 OpenBSD/hppa hppa*-*-openbsd*
2969 OpenBSD/m68k m68*-*-openbsd*
2970 OpenBSD/m88k m88*-*-openbsd*
2971 OpenBSD/powerpc powerpc-*-openbsd*
2972 NetBSD/vax vax-*-netbsd*
2973 OpenBSD/vax vax-*-openbsd*
2975 * END-OF-LIFE frame compatibility module
2977 GDB's internal frame infrastructure has been completely rewritten.
2978 The new infrastructure making it possible to support key new features
2979 including DWARF 2 Call Frame Information. To aid in the task of
2980 migrating old configurations to this new infrastructure, a
2981 compatibility module, that allowed old configurations to continue to
2982 work, was also included.
2984 GDB 6.2 will be the last release to include this frame compatibility
2985 module. This change directly impacts the following configurations:
2995 Unless there is activity to revive these configurations, they will be
2996 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2998 * REMOVED configurations and files
3000 Sun 3, running SunOS 3 m68*-*-sunos3*
3001 Sun 3, running SunOS 4 m68*-*-sunos4*
3002 Sun 2, running SunOS 3 m68000-*-sunos3*
3003 Sun 2, running SunOS 4 m68000-*-sunos4*
3004 Motorola 680x0 running LynxOS m68*-*-lynxos*
3005 AT&T 3b1/Unix pc m68*-att-*
3006 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3007 decstation mips-dec-* mips-little-*
3008 riscos mips-*-riscos* mips-*-sysv*
3009 sonymips mips-sony-*
3010 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3012 *** Changes in GDB 6.1.1:
3014 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3016 The TUI (Text-mode User Interface) is now built as part of a default
3017 GDB configuration. It is enabled by either selecting the TUI with the
3018 command line option "-i=tui" or by running the separate "gdbtui"
3019 program. For more information on the TUI, see the manual "Debugging
3022 * Pending breakpoint support (also included in GDB 6.1)
3024 Support has been added to allow you to specify breakpoints in shared
3025 libraries that have not yet been loaded. If a breakpoint location
3026 cannot be found, and the "breakpoint pending" option is set to auto,
3027 GDB queries you if you wish to make the breakpoint pending on a future
3028 shared-library load. If and when GDB resolves the breakpoint symbol,
3029 the pending breakpoint is removed as one or more regular breakpoints
3032 Pending breakpoints are very useful for GCJ Java debugging.
3034 * Fixed ISO-C build problems
3036 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3037 non ISO-C code that stopped them being built using a more strict ISO-C
3038 compiler (e.g., IBM's C compiler).
3040 * Fixed build problem on IRIX 5
3042 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3043 wasn't able to compile compile on an IRIX 5 system.
3045 * Added execute permission to gdb/gdbserver/configure
3047 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3048 permission. This bug would cause configure to fail on a number of
3049 systems (Solaris, IRIX). Ref: server/519.
3051 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3053 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3054 has been updated to use constant array sizes.
3056 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3058 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3059 its generated DWARF Call Frame Info. This encoding was causing GDB to
3060 panic, that panic has been fixed. Ref: gdb/1628.
3062 * Fixed a problem when examining parameters in shared library code.
3064 When examining parameters in optimized shared library code generated
3065 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3066 not available''. GDB now correctly displays the variable's value.
3068 *** Changes in GDB 6.1:
3070 * Removed --with-mmalloc
3072 Support for the mmalloc memory manager has been removed, as it
3073 conflicted with the internal gdb byte cache.
3075 * Changes in AMD64 configurations
3077 The AMD64 target now includes the %cs and %ss registers. As a result
3078 the AMD64 remote protocol has changed; this affects the floating-point
3079 and SSE registers. If you rely on those registers for your debugging,
3080 you should upgrade gdbserver on the remote side.
3082 * Revised SPARC target
3084 The SPARC target has been completely revised, incorporating the
3085 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3086 support for LynxOS and SunOS 4 has been dropped. Calling functions
3087 from within GDB on operating systems with a non-executable stack
3088 (Solaris, OpenBSD) now works.
3092 GDB has a new C++ demangler which does a better job on the mangled
3093 names generated by current versions of g++. It also runs faster, so
3094 with this and other changes gdb should now start faster on large C++
3097 * DWARF 2 Location Expressions
3099 GDB support for location expressions has been extended to support function
3100 arguments and frame bases. Older versions of GDB could crash when they
3103 * C++ nested types and namespaces
3105 GDB's support for nested types and namespaces in C++ has been
3106 improved, especially if you use the DWARF 2 debugging format. (This
3107 is the default for recent versions of GCC on most platforms.)
3108 Specifically, if you have a class "Inner" defined within a class or
3109 namespace "Outer", then GDB realizes that the class's name is
3110 "Outer::Inner", not simply "Inner". This should greatly reduce the
3111 frequency of complaints about not finding RTTI symbols. In addition,
3112 if you are stopped at inside of a function defined within a namespace,
3113 GDB modifies its name lookup accordingly.
3115 * New native configurations
3117 NetBSD/amd64 x86_64-*-netbsd*
3118 OpenBSD/amd64 x86_64-*-openbsd*
3119 OpenBSD/alpha alpha*-*-openbsd*
3120 OpenBSD/sparc sparc-*-openbsd*
3121 OpenBSD/sparc64 sparc64-*-openbsd*
3123 * New debugging protocols
3125 M32R with SDI protocol m32r-*-elf*
3127 * "set prompt-escape-char" command deleted.
3129 The command "set prompt-escape-char" has been deleted. This command,
3130 and its very obscure effet on GDB's prompt, was never documented,
3131 tested, nor mentioned in the NEWS file.
3133 * OBSOLETE configurations and files
3135 Configurations that have been declared obsolete in this release have
3136 been commented out. Unless there is activity to revive these
3137 configurations, the next release of GDB will have their sources
3138 permanently REMOVED.
3140 Sun 3, running SunOS 3 m68*-*-sunos3*
3141 Sun 3, running SunOS 4 m68*-*-sunos4*
3142 Sun 2, running SunOS 3 m68000-*-sunos3*
3143 Sun 2, running SunOS 4 m68000-*-sunos4*
3144 Motorola 680x0 running LynxOS m68*-*-lynxos*
3145 AT&T 3b1/Unix pc m68*-att-*
3146 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3147 decstation mips-dec-* mips-little-*
3148 riscos mips-*-riscos* mips-*-sysv*
3149 sonymips mips-sony-*
3150 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3152 * REMOVED configurations and files
3154 SGI Irix-4.x mips-sgi-irix4 or iris4
3155 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3156 Z8000 simulator z8k-zilog-none or z8ksim
3157 Matsushita MN10200 w/simulator mn10200-*-*
3158 H8/500 simulator h8500-hitachi-hms or h8500hms
3159 HP/PA running BSD hppa*-*-bsd*
3160 HP/PA running OSF/1 hppa*-*-osf*
3161 HP/PA Pro target hppa*-*-pro*
3162 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3163 386BSD i[3456]86-*-bsd*
3164 Sequent family i[3456]86-sequent-sysv4*
3165 i[3456]86-sequent-sysv*
3166 i[3456]86-sequent-bsd*
3167 SPARC running LynxOS sparc-*-lynxos*
3168 SPARC running SunOS 4 sparc-*-sunos4*
3169 Tsqware Sparclet sparclet-*-*
3170 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3172 *** Changes in GDB 6.0:
3176 Support for debugging the Objective-C programming language has been
3177 integrated into GDB.
3179 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3181 DWARF 2's Call Frame Information makes available compiler generated
3182 information that more exactly describes the program's run-time stack.
3183 By using this information, GDB is able to provide more robust stack
3186 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3187 have been updated to use a new backtrace mechanism which includes
3188 DWARF 2 CFI support.
3192 GDB's remote protocol has been extended to include support for hosted
3193 file I/O (where the remote target uses GDB's file system). See GDB's
3194 remote protocol documentation for details.
3196 * All targets using the new architecture framework.
3198 All of GDB's targets have been updated to use the new internal
3199 architecture framework. The way is now open for future GDB releases
3200 to include cross-architecture native debugging support (i386 on amd64,
3203 * GNU/Linux's Thread Local Storage (TLS)
3205 GDB now includes support for for the GNU/Linux implementation of
3206 per-thread variables.
3208 * GNU/Linux's Native POSIX Thread Library (NPTL)
3210 GDB's thread code has been updated to work with either the new
3211 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3213 * Separate debug info.
3215 GDB, in conjunction with BINUTILS, now supports a mechanism for
3216 automatically loading debug information from a separate file. Instead
3217 of shipping full debug and non-debug versions of system libraries,
3218 system integrators can now instead ship just the stripped libraries
3219 and optional debug files.
3221 * DWARF 2 Location Expressions
3223 DWARF 2 Location Expressions allow the compiler to more completely
3224 describe the location of variables (even in optimized code) to the
3227 GDB now includes preliminary support for location expressions (support
3228 for DW_OP_piece is still missing).
3232 A number of long standing bugs that caused GDB to die while starting a
3233 Java application have been fixed. GDB's Java support is now
3234 considered "useable".
3236 * GNU/Linux support for fork, vfork, and exec.
3238 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3239 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3242 * GDB supports logging output to a file
3244 There are two new commands, "set logging" and "show logging", which can be
3245 used to capture GDB's output to a file.
3247 * The meaning of "detach" has changed for gdbserver
3249 The "detach" command will now resume the application, as documented. To
3250 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3253 * d10v, m68hc11 `regs' command deprecated
3255 The `info registers' command has been updated so that it displays the
3256 registers using a format identical to the old `regs' command.
3260 A new command, "maint set profile on/off", has been added. This command can
3261 be used to enable or disable profiling while running GDB, to profile a
3262 session or a set of commands. In addition there is a new configure switch,
3263 "--enable-profiling", which will cause GDB to be compiled with profiling
3264 data, for more informative profiling results.
3266 * Default MI syntax changed to "mi2".
3268 The default MI (machine interface) syntax, enabled by the command line
3269 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3270 "mi1", can be enabled by specifying the option "-i=mi1".
3272 Support for the original "mi0" syntax (included in GDB 5.0) has been
3275 Fix for gdb/192: removed extraneous space when displaying frame level.
3276 Fix for gdb/672: update changelist is now output in mi list format.
3277 Fix for gdb/702: a -var-assign that updates the value now shows up
3278 in a subsequent -var-update.
3280 * New native configurations.
3282 FreeBSD/amd64 x86_64-*-freebsd*
3284 * Multi-arched targets.
3286 HP/PA HPUX11 hppa*-*-hpux*
3287 Renesas M32R/D w/simulator m32r-*-elf*
3289 * OBSOLETE configurations and files
3291 Configurations that have been declared obsolete in this release have
3292 been commented out. Unless there is activity to revive these
3293 configurations, the next release of GDB will have their sources
3294 permanently REMOVED.
3296 Z8000 simulator z8k-zilog-none or z8ksim
3297 Matsushita MN10200 w/simulator mn10200-*-*
3298 H8/500 simulator h8500-hitachi-hms or h8500hms
3299 HP/PA running BSD hppa*-*-bsd*
3300 HP/PA running OSF/1 hppa*-*-osf*
3301 HP/PA Pro target hppa*-*-pro*
3302 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3303 Sequent family i[3456]86-sequent-sysv4*
3304 i[3456]86-sequent-sysv*
3305 i[3456]86-sequent-bsd*
3306 Tsqware Sparclet sparclet-*-*
3307 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3309 * REMOVED configurations and files
3312 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3313 IBM AIX PS/2 i[3456]86-*-aix
3314 i386 running Mach 3.0 i[3456]86-*-mach3*
3315 i386 running Mach i[3456]86-*-mach*
3316 i386 running OSF/1 i[3456]86-*osf1mk*
3317 HP/Apollo 68k Family m68*-apollo*-sysv*,
3319 m68*-hp-bsd*, m68*-hp-hpux*
3320 Argonaut Risc Chip (ARC) arc-*-*
3321 Mitsubishi D30V d30v-*-*
3322 Fujitsu FR30 fr30-*-elf*
3323 OS/9000 i[34]86-*-os9k
3324 I960 with MON960 i960-*-coff
3326 * MIPS $fp behavior changed
3328 The convenience variable $fp, for the MIPS, now consistently returns
3329 the address of the current frame's base. Previously, depending on the
3330 context, $fp could refer to either $sp or the current frame's base
3331 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3332 The GNU Source-Level Debugger''.
3334 *** Changes in GDB 5.3:
3336 * GNU/Linux shared library multi-threaded performance improved.
3338 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3339 `/proc', in preference to `ptrace' for memory reads. This may result
3340 in an improvement in the start-up time of multi-threaded, shared
3341 library applications when run under GDB. One GDB user writes: ``loads
3342 shared libs like mad''.
3344 * ``gdbserver'' now supports multi-threaded applications on some targets
3346 Support for debugging multi-threaded applications which use
3347 the GNU/Linux LinuxThreads package has been added for
3348 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3349 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3351 * GDB now supports C/C++ preprocessor macros.
3353 GDB now expands preprocessor macro invocations in C/C++ expressions,
3354 and provides various commands for showing macro definitions and how
3357 The new command `macro expand EXPRESSION' expands any macro
3358 invocations in expression, and shows the result.
3360 The new command `show macro MACRO-NAME' shows the definition of the
3361 macro named MACRO-NAME, and where it was defined.
3363 Most compilers don't include information about macros in the debugging
3364 information by default. In GCC 3.1, for example, you need to compile
3365 your program with the options `-gdwarf-2 -g3'. If the macro
3366 information is present in the executable, GDB will read it.
3368 * Multi-arched targets.
3370 DEC Alpha (partial) alpha*-*-*
3371 DEC VAX (partial) vax-*-*
3373 National Semiconductor NS32000 (partial) ns32k-*-*
3374 Motorola 68000 (partial) m68k-*-*
3375 Motorola MCORE mcore-*-*
3379 Fujitsu FRV architecture added by Red Hat frv*-*-*
3382 * New native configurations
3384 Alpha NetBSD alpha*-*-netbsd*
3385 SH NetBSD sh*-*-netbsdelf*
3386 MIPS NetBSD mips*-*-netbsd*
3387 UltraSPARC NetBSD sparc64-*-netbsd*
3389 * OBSOLETE configurations and files
3391 Configurations that have been declared obsolete in this release have
3392 been commented out. Unless there is activity to revive these
3393 configurations, the next release of GDB will have their sources
3394 permanently REMOVED.
3396 Mitsubishi D30V d30v-*-*
3397 OS/9000 i[34]86-*-os9k
3398 IBM AIX PS/2 i[3456]86-*-aix
3399 Fujitsu FR30 fr30-*-elf*
3400 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3401 Argonaut Risc Chip (ARC) arc-*-*
3402 i386 running Mach 3.0 i[3456]86-*-mach3*
3403 i386 running Mach i[3456]86-*-mach*
3404 i386 running OSF/1 i[3456]86-*osf1mk*
3405 HP/Apollo 68k Family m68*-apollo*-sysv*,
3407 m68*-hp-bsd*, m68*-hp-hpux*
3408 I960 with MON960 i960-*-coff
3410 * OBSOLETE languages
3412 CHILL, a Pascal like language used by telecommunications companies.
3414 * REMOVED configurations and files
3416 AMD 29k family via UDI a29k-amd-udi, udi29k
3417 A29K VxWorks a29k-*-vxworks
3418 AMD 29000 embedded, using EBMON a29k-none-none
3419 AMD 29000 embedded with COFF a29k-none-coff
3420 AMD 29000 embedded with a.out a29k-none-aout
3422 testsuite/gdb.hp/gdb.threads-hp/ directory
3424 * New command "set max-user-call-depth <nnn>"
3426 This command allows the user to limit the call depth of user-defined
3427 commands. The default is 1024.
3429 * Changes in FreeBSD/i386 native debugging.
3431 Support for the "generate-core-file" has been added.
3433 * New commands "dump", "append", and "restore".
3435 These commands allow data to be copied from target memory
3436 to a bfd-format or binary file (dump and append), and back
3437 from a file into memory (restore).
3439 * Improved "next/step" support on multi-processor Alpha Tru64.
3441 The previous single-step mechanism could cause unpredictable problems,
3442 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3443 of a software single-step mechanism prevents this.
3445 *** Changes in GDB 5.2.1:
3453 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3454 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3455 Fix, by Joel Brobecker imported from mainline.
3457 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3458 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3459 Fix, by Fred Fish, imported from mainline.
3461 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3462 Surprisingly enough, it works now.
3463 By Michal Ludvig, imported from mainline.
3465 i386 hardware watchpoint support:
3466 avoid misses on second run for some targets.
3467 By Pierre Muller, imported from mainline.
3469 *** Changes in GDB 5.2:
3471 * New command "set trust-readonly-sections on[off]".
3473 This command is a hint that tells gdb that read-only sections
3474 really are read-only (ie. that their contents will not change).
3475 In this mode, gdb will go to the object file rather than the
3476 target to read memory from read-only sections (such as ".text").
3477 This can be a significant performance improvement on some
3478 (notably embedded) targets.
3480 * New command "generate-core-file" (or "gcore").
3482 This new gdb command allows the user to drop a core file of the child
3483 process state at any time. So far it's been implemented only for
3484 GNU/Linux and Solaris, but should be relatively easily ported to other
3485 hosts. Argument is core file name (defaults to core.<pid>).
3487 * New command line option
3489 GDB now accepts --pid or -p followed by a process id.
3491 * Change in command line behavior -- corefiles vs. process ids.
3493 There is a subtle behavior in the way in which GDB handles
3494 command line arguments. The first non-flag argument is always
3495 a program to debug, but the second non-flag argument may either
3496 be a corefile or a process id. Previously, GDB would attempt to
3497 open the second argument as a corefile, and if that failed, would
3498 issue a superfluous error message and then attempt to attach it as
3499 a process. Now, if the second argument begins with a non-digit,
3500 it will be treated as a corefile. If it begins with a digit,
3501 GDB will attempt to attach it as a process, and if no such process
3502 is found, will then attempt to open it as a corefile.
3504 * Changes in ARM configurations.
3506 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3507 configuration is fully multi-arch.
3509 * New native configurations
3511 ARM NetBSD arm*-*-netbsd*
3512 x86 OpenBSD i[3456]86-*-openbsd*
3513 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3514 Sparc64 running FreeBSD sparc64-*-freebsd*
3518 Sanyo XStormy16 xstormy16-elf
3520 * OBSOLETE configurations and files
3522 Configurations that have been declared obsolete in this release have
3523 been commented out. Unless there is activity to revive these
3524 configurations, the next release of GDB will have their sources
3525 permanently REMOVED.
3527 AMD 29k family via UDI a29k-amd-udi, udi29k
3528 A29K VxWorks a29k-*-vxworks
3529 AMD 29000 embedded, using EBMON a29k-none-none
3530 AMD 29000 embedded with COFF a29k-none-coff
3531 AMD 29000 embedded with a.out a29k-none-aout
3533 testsuite/gdb.hp/gdb.threads-hp/ directory
3535 * REMOVED configurations and files
3537 TI TMS320C80 tic80-*-*
3539 PowerPC Solaris powerpcle-*-solaris*
3540 PowerPC Windows NT powerpcle-*-cygwin32
3541 PowerPC Netware powerpc-*-netware*
3542 Harris/CXUX m88k m88*-harris-cxux*
3543 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3544 ns32k-utek-sysv* ns32k-utek-*
3545 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3546 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3547 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3548 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3549 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3551 * Changes to command line processing
3553 The new `--args' feature can be used to specify command-line arguments
3554 for the inferior from gdb's command line.
3556 * Changes to key bindings
3558 There is a new `operate-and-get-next' function bound to `C-o'.
3560 *** Changes in GDB 5.1.1
3562 Fix compile problem on DJGPP.
3564 Fix a problem with floating-point registers on the i386 being
3567 Fix to stop GDB crashing on .debug_str debug info.
3569 Numerous documentation fixes.
3571 Numerous testsuite fixes.
3573 *** Changes in GDB 5.1:
3575 * New native configurations
3577 Alpha FreeBSD alpha*-*-freebsd*
3578 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3579 MIPS GNU/Linux mips*-*-linux*
3580 MIPS SGI Irix 6.x mips*-sgi-irix6*
3581 ia64 AIX ia64-*-aix*
3582 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3586 Motorola 68HC11 and 68HC12 m68hc11-elf
3588 UltraSparc running GNU/Linux sparc64-*-linux*
3590 * OBSOLETE configurations and files
3592 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3593 Harris/CXUX m88k m88*-harris-cxux*
3594 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3595 ns32k-utek-sysv* ns32k-utek-*
3596 TI TMS320C80 tic80-*-*
3598 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3599 PowerPC Solaris powerpcle-*-solaris*
3600 PowerPC Windows NT powerpcle-*-cygwin32
3601 PowerPC Netware powerpc-*-netware*
3602 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3603 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3604 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3605 Apple Macintosh (MPW) host N/A
3607 stuff.c (Program to stuff files into a specially prepared space in kdb)
3608 kdb-start.c (Main loop for the standalone kernel debugger)
3610 Configurations that have been declared obsolete in this release have
3611 been commented out. Unless there is activity to revive these
3612 configurations, the next release of GDB will have their sources
3613 permanently REMOVED.
3615 * REMOVED configurations and files
3617 Altos 3068 m68*-altos-*
3618 Convex c1-*-*, c2-*-*
3620 ARM RISCix arm-*-* (as host)
3624 * GDB has been converted to ISO C.
3626 GDB's source code has been converted to ISO C. In particular, the
3627 sources are fully protoized, and rely on standard headers being
3632 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3634 * The MI enabled by default.
3636 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3637 revised and enabled by default. Packages which use GDB as a debugging
3638 engine behind a UI or another front end are encouraged to switch to
3639 using the GDB/MI interface, instead of the old annotations interface
3640 which is now deprecated.
3642 * Support for debugging Pascal programs.
3644 GDB now includes support for debugging Pascal programs. The following
3645 main features are supported:
3647 - Pascal-specific data types such as sets;
3649 - automatic recognition of Pascal sources based on file-name
3652 - Pascal-style display of data types, variables, and functions;
3654 - a Pascal expression parser.
3656 However, some important features are not yet supported.
3658 - Pascal string operations are not supported at all;
3660 - there are some problems with boolean types;
3662 - Pascal type hexadecimal constants are not supported
3663 because they conflict with the internal variables format;
3665 - support for Pascal objects and classes is not full yet;
3667 - unlike Pascal, GDB is case-sensitive for symbol names.
3669 * Changes in completion.
3671 Commands such as `shell', `run' and `set args', which pass arguments
3672 to inferior programs, now complete on file names, similar to what
3673 users expect at the shell prompt.
3675 Commands which accept locations, such as `disassemble', `print',
3676 `breakpoint', `until', etc. now complete on filenames as well as
3677 program symbols. Thus, if you type "break foob TAB", and the source
3678 files linked into the programs include `foobar.c', that file name will
3679 be one of the candidates for completion. However, file names are not
3680 considered for completion after you typed a colon that delimits a file
3681 name from a name of a function in that file, as in "break foo.c:bar".
3683 `set demangle-style' completes on available demangling styles.
3685 * New platform-independent commands:
3687 It is now possible to define a post-hook for a command as well as a
3688 hook that runs before the command. For more details, see the
3689 documentation of `hookpost' in the GDB manual.
3691 * Changes in GNU/Linux native debugging.
3693 Support for debugging multi-threaded programs has been completely
3694 revised for all platforms except m68k and sparc. You can now debug as
3695 many threads as your system allows you to have.
3697 Attach/detach is supported for multi-threaded programs.
3699 Support for SSE registers was added for x86. This doesn't work for
3700 multi-threaded programs though.
3702 * Changes in MIPS configurations.
3704 Multi-arch support is enabled for all MIPS configurations.
3706 GDB can now be built as native debugger on SGI Irix 6.x systems for
3707 debugging n32 executables. (Debugging 64-bit executables is not yet
3710 * Unified support for hardware watchpoints in all x86 configurations.
3712 Most (if not all) native x86 configurations support hardware-assisted
3713 breakpoints and watchpoints in a unified manner. This support
3714 implements debug register sharing between watchpoints, which allows to
3715 put a virtually infinite number of watchpoints on the same address,
3716 and also supports watching regions up to 16 bytes with several debug
3719 The new maintenance command `maintenance show-debug-regs' toggles
3720 debugging print-outs in functions that insert, remove, and test
3721 watchpoints and hardware breakpoints.
3723 * Changes in the DJGPP native configuration.
3725 New command ``info dos sysinfo'' displays assorted information about
3726 the CPU, OS, memory, and DPMI server.
3728 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3729 display information about segment descriptors stored in GDT, LDT, and
3732 New commands ``info dos pde'' and ``info dos pte'' display entries
3733 from Page Directory and Page Tables (for now works with CWSDPMI only).
3734 New command ``info dos address-pte'' displays the Page Table entry for
3735 a given linear address.
3737 GDB can now pass command lines longer than 126 characters to the
3738 program being debugged (requires an update to the libdbg.a library
3739 which is part of the DJGPP development kit).
3741 DWARF2 debug info is now supported.
3743 It is now possible to `step' and `next' through calls to `longjmp'.
3745 * Changes in documentation.
3747 All GDB documentation was converted to GFDL, the GNU Free
3748 Documentation License.
3750 Tracepoints-related commands are now fully documented in the GDB
3753 TUI, the Text-mode User Interface, is now documented in the manual.
3755 Tracepoints-related commands are now fully documented in the GDB
3758 The "GDB Internals" manual now has an index. It also includes
3759 documentation of `ui_out' functions, GDB coding standards, x86
3760 hardware watchpoints, and memory region attributes.
3762 * GDB's version number moved to ``version.in''
3764 The Makefile variable VERSION has been replaced by the file
3765 ``version.in''. People creating GDB distributions should update the
3766 contents of this file.
3770 GUD support is now a standard part of the EMACS distribution.
3772 *** Changes in GDB 5.0:
3774 * Improved support for debugging FP programs on x86 targets
3776 Unified and much-improved support for debugging floating-point
3777 programs on all x86 targets. In particular, ``info float'' now
3778 displays the FP registers in the same format on all x86 targets, with
3779 greater level of detail.
3781 * Improvements and bugfixes in hardware-assisted watchpoints
3783 It is now possible to watch array elements, struct members, and
3784 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3785 on x86 targets no longer erroneously trigger when the address is
3788 * Improvements in the native DJGPP version of GDB
3790 The distribution now includes all the scripts and auxiliary files
3791 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3792 machines ``out of the box''.
3794 The DJGPP version can now debug programs that use signals. It is
3795 possible to catch signals that happened in the debuggee, deliver
3796 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3797 would kill the program being debugged.) Programs that hook hardware
3798 interrupts (keyboard, timer, etc.) can also be debugged.
3800 It is now possible to debug DJGPP programs that redirect their
3801 standard handles or switch them to raw (as opposed to cooked) mode, or
3802 even close them. The command ``run < foo > bar'' works as expected,
3803 and ``info terminal'' reports useful information about the debuggee's
3804 terminal, including raw/cooked mode, redirection, etc.
3806 The DJGPP version now uses termios functions for console I/O, which
3807 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3810 DOS-style file names with drive letters are now fully supported by
3813 It is now possible to debug DJGPP programs that switch their working
3814 directory. It is also possible to rerun the debuggee any number of
3815 times without restarting GDB; thus, you can use the same setup,
3816 breakpoints, etc. for many debugging sessions.
3818 * New native configurations
3820 ARM GNU/Linux arm*-*-linux*
3821 PowerPC GNU/Linux powerpc-*-linux*
3825 Motorola MCore mcore-*-*
3826 x86 VxWorks i[3456]86-*-vxworks*
3827 PowerPC VxWorks powerpc-*-vxworks*
3828 TI TMS320C80 tic80-*-*
3830 * OBSOLETE configurations
3832 Altos 3068 m68*-altos-*
3833 Convex c1-*-*, c2-*-*
3835 ARM RISCix arm-*-* (as host)
3838 Configurations that have been declared obsolete will be commented out,
3839 but the code will be left in place. If there is no activity to revive
3840 these configurations before the next release of GDB, the sources will
3841 be permanently REMOVED.
3843 * Gould support removed
3845 Support for the Gould PowerNode and NP1 has been removed.
3847 * New features for SVR4
3849 On SVR4 native platforms (such as Solaris), if you attach to a process
3850 without first loading a symbol file, GDB will now attempt to locate and
3851 load symbols from the running process's executable file.
3853 * Many C++ enhancements
3855 C++ support has been greatly improved. Overload resolution now works properly
3856 in almost all cases. RTTI support is on the way.
3858 * Remote targets can connect to a sub-program
3860 A popen(3) style serial-device has been added. This device starts a
3861 sub-process (such as a stand-alone simulator) and then communicates
3862 with that. The sub-program to run is specified using the syntax
3863 ``|<program> <args>'' vis:
3865 (gdb) set remotedebug 1
3866 (gdb) target extended-remote |mn10300-elf-sim program-args
3868 * MIPS 64 remote protocol
3870 A long standing bug in the mips64 remote protocol where by GDB
3871 expected certain 32 bit registers (ex SR) to be transfered as 32
3872 instead of 64 bits has been fixed.
3874 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3875 added to provide backward compatibility with older versions of GDB.
3877 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3879 The command ``set remotebinarydownload'' command has been replaced by
3880 ``set remote X-packet''. Other commands in ``set remote'' family
3881 include ``set remote P-packet''.
3883 * Breakpoint commands accept ranges.
3885 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3886 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3887 ``tracepoint passcount'' also accepts a range of tracepoints.
3889 * ``apropos'' command added.
3891 The ``apropos'' command searches through command names and
3892 documentation strings, printing out matches, making it much easier to
3893 try to find a command that does what you are looking for.
3897 A new machine oriented interface (MI) has been added to GDB. This
3898 interface is designed for debug environments running GDB as a separate
3899 process. This is part of the long term libGDB project. See the
3900 "GDB/MI" chapter of the GDB manual for further information. It can be
3901 enabled by configuring with:
3903 .../configure --enable-gdbmi
3905 *** Changes in GDB-4.18:
3907 * New native configurations
3909 HP-UX 10.20 hppa*-*-hpux10.20
3910 HP-UX 11.x hppa*-*-hpux11.0*
3911 M68K GNU/Linux m68*-*-linux*
3915 Fujitsu FR30 fr30-*-elf*
3916 Intel StrongARM strongarm-*-*
3917 Mitsubishi D30V d30v-*-*
3919 * OBSOLETE configurations
3921 Gould PowerNode, NP1 np1-*-*, pn-*-*
3923 Configurations that have been declared obsolete will be commented out,
3924 but the code will be left in place. If there is no activity to revive
3925 these configurations before the next release of GDB, the sources will
3926 be permanently REMOVED.
3930 As a compatibility experiment, GDB's source files buildsym.h and
3931 buildsym.c have been converted to pure standard C, no longer
3932 containing any K&R compatibility code. We believe that all systems in
3933 use today either come with a standard C compiler, or have a GCC port
3934 available. If this is not true, please report the affected
3935 configuration to bug-gdb@gnu.org immediately. See the README file for
3936 information about getting a standard C compiler if you don't have one
3941 GDB now uses readline 2.2.
3943 * set extension-language
3945 You can now control the mapping between filename extensions and source
3946 languages by using the `set extension-language' command. For instance,
3947 you can ask GDB to treat .c files as C++ by saying
3948 set extension-language .c c++
3949 The command `info extensions' lists all of the recognized extensions
3950 and their associated languages.
3952 * Setting processor type for PowerPC and RS/6000
3954 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3955 you can use the `set processor' command to specify what variant of the
3956 PowerPC family you are debugging. The command
3960 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3961 following PowerPC and RS6000 variants:
3963 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3964 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3966 403GC IBM PowerPC 403GC
3967 505 Motorola PowerPC 505
3968 860 Motorola PowerPC 860 or 850
3969 601 Motorola PowerPC 601
3970 602 Motorola PowerPC 602
3971 603 Motorola/IBM PowerPC 603 or 603e
3972 604 Motorola PowerPC 604 or 604e
3973 750 Motorola/IBM PowerPC 750 or 750
3975 At the moment, this command just tells GDB what to name the
3976 special-purpose processor registers. Since almost all the affected
3977 registers are inaccessible to user-level programs, this command is
3978 only useful for remote debugging in its present form.
3982 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3983 more extensive support for HP-UX. Added features include shared
3984 library support, kernel threads and hardware watchpoints for 11.00,
3985 support for HP's ANSI C and C++ compilers, and a compatibility mode
3986 for xdb and dbx commands.
3990 HP's donation includes the new concept of catchpoints, which is a
3991 generalization of the old catch command. On HP-UX, it is now possible
3992 to catch exec, fork, and vfork, as well as library loading.
3994 This means that the existing catch command has changed; its first
3995 argument now specifies the type of catch to be set up. See the
3996 output of "help catch" for a list of catchpoint types.
3998 * Debugging across forks
4000 On HP-UX, you can choose which process to debug when a fork() happens
4005 HP has donated a curses-based terminal user interface (TUI). To get
4006 it, build with --enable-tui. Although this can be enabled for any
4007 configuration, at present it only works for native HP debugging.
4009 * GDB remote protocol additions
4011 A new protocol packet 'X' that writes binary data is now available.
4012 Default behavior is to try 'X', then drop back to 'M' if the stub
4013 fails to respond. The settable variable `remotebinarydownload'
4014 allows explicit control over the use of 'X'.
4016 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4017 full 64-bit address. The command
4019 set remoteaddresssize 32
4021 can be used to revert to the old behaviour. For existing remote stubs
4022 the change should not be noticed, as the additional address information
4025 In order to assist in debugging stubs, you may use the maintenance
4026 command `packet' to send any text string to the stub. For instance,
4028 maint packet heythere
4030 sends the packet "$heythere#<checksum>". Note that it is very easy to
4031 disrupt a debugging session by sending the wrong packet at the wrong
4034 The compare-sections command allows you to compare section data on the
4035 target to what is in the executable file without uploading or
4036 downloading, by comparing CRC checksums.
4038 * Tracing can collect general expressions
4040 You may now collect general expressions at tracepoints. This requires
4041 further additions to the target-side stub; see tracepoint.c and
4042 doc/agentexpr.texi for further details.
4044 * mask-address variable for Mips
4046 For Mips targets, you may control the zeroing of the upper 32 bits of
4047 a 64-bit address by entering `set mask-address on'. This is mainly
4048 of interest to users of embedded R4xxx and R5xxx processors.
4050 * Higher serial baud rates
4052 GDB's serial code now allows you to specify baud rates 57600, 115200,
4053 230400, and 460800 baud. (Note that your host system may not be able
4054 to achieve all of these rates.)
4058 The i960 configuration now includes an initial implementation of a
4059 builtin simulator, contributed by Jim Wilson.
4062 *** Changes in GDB-4.17:
4064 * New native configurations
4066 Alpha GNU/Linux alpha*-*-linux*
4067 Unixware 2.x i[3456]86-unixware2*
4068 Irix 6.x mips*-sgi-irix6*
4069 PowerPC GNU/Linux powerpc-*-linux*
4070 PowerPC Solaris powerpcle-*-solaris*
4071 Sparc GNU/Linux sparc-*-linux*
4072 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4076 Argonaut Risc Chip (ARC) arc-*-*
4077 Hitachi H8/300S h8300*-*-*
4078 Matsushita MN10200 w/simulator mn10200-*-*
4079 Matsushita MN10300 w/simulator mn10300-*-*
4080 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4081 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4082 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4083 Mitsubishi D10V w/simulator d10v-*-*
4084 Mitsubishi M32R/D w/simulator m32r-*-elf*
4085 Tsqware Sparclet sparclet-*-*
4086 NEC V850 w/simulator v850-*-*
4088 * New debugging protocols
4090 ARM with RDI protocol arm*-*-*
4091 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4092 DDB and LSI variants of PMON protocol mips*-*-*
4093 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4094 PowerPC with SDS protocol powerpc{,le}-*-eabi
4095 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4099 All configurations can now understand and use the DWARF 2 debugging
4100 format. The choice is automatic, if the symbol file contains DWARF 2
4105 GDB now includes basic Java language support. This support is
4106 only useful with Java compilers that produce native machine code.
4108 * solib-absolute-prefix and solib-search-path
4110 For SunOS and SVR4 shared libraries, you may now set the prefix for
4111 loading absolute shared library symbol files, and the search path for
4112 locating non-absolute shared library symbol files.
4114 * Live range splitting
4116 GDB can now effectively debug code for which GCC has performed live
4117 range splitting as part of its optimization. See gdb/doc/LRS for
4118 more details on the expected format of the stabs information.
4122 GDB's support for the GNU Hurd, including thread debugging, has been
4123 updated to work with current versions of the Hurd.
4127 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4128 instruction set. ARM GDB automatically detects when Thumb
4129 instructions are in use, and adjusts disassembly and backtracing
4134 GDB's MIPS target configurations now handle the MIP16 16-bit
4139 GDB now includes support for overlays; if an executable has been
4140 linked such that multiple sections are based at the same address, GDB
4141 will decide which section to use for symbolic info. You can choose to
4142 control the decision manually, using overlay commands, or implement
4143 additional target-side support and use "overlay load-target" to bring
4144 in the overlay mapping. Do "help overlay" for more detail.
4148 The command "info symbol <address>" displays information about
4149 the symbol at the specified address.
4153 The standard remote protocol now includes an extension that allows
4154 asynchronous collection and display of trace data. This requires
4155 extensive support in the target-side debugging stub. Tracing mode
4156 includes a new interaction mode in GDB and new commands: see the
4157 file tracepoint.c for more details.
4161 Configurations for embedded MIPS now include a simulator contributed
4162 by Cygnus Solutions. The simulator supports the instruction sets
4163 of most MIPS variants.
4167 Sparc configurations may now include the ERC32 simulator contributed
4168 by the European Space Agency. The simulator is not built into
4169 Sparc targets by default; configure with --enable-sim to include it.
4173 For target configurations that may include multiple variants of a
4174 basic architecture (such as MIPS and SH), you may now set the
4175 architecture explicitly. "set arch" sets, "info arch" lists
4176 the possible architectures.
4178 *** Changes in GDB-4.16:
4180 * New native configurations
4182 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4183 M68K NetBSD m68k-*-netbsd*
4184 PowerPC AIX 4.x powerpc-*-aix*
4185 PowerPC MacOS powerpc-*-macos*
4186 PowerPC Windows NT powerpcle-*-cygwin32
4187 RS/6000 AIX 4.x rs6000-*-aix4*
4191 ARM with RDP protocol arm-*-*
4192 I960 with MON960 i960-*-coff
4193 MIPS VxWorks mips*-*-vxworks*
4194 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4195 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4197 Matra Sparclet sparclet-*-*
4201 The powerpc-eabi configuration now includes the PSIM simulator,
4202 contributed by Andrew Cagney, with assistance from Mike Meissner.
4203 PSIM is a very elaborate model of the PowerPC, including not only
4204 basic instruction set execution, but also details of execution unit
4205 performance and I/O hardware. See sim/ppc/README for more details.
4209 GDB now works with Solaris 2.5.
4211 * Windows 95/NT native
4213 GDB will now work as a native debugger on Windows 95 and Windows NT.
4214 To build it from source, you must use the "gnu-win32" environment,
4215 which uses a DLL to emulate enough of Unix to run the GNU tools.
4216 Further information, binaries, and sources are available at
4217 ftp.cygnus.com, under pub/gnu-win32.
4219 * dont-repeat command
4221 If a user-defined command includes the command `dont-repeat', then the
4222 command will not be repeated if the user just types return. This is
4223 useful if the command is time-consuming to run, so that accidental
4224 extra keystrokes don't run the same command many times.
4226 * Send break instead of ^C
4228 The standard remote protocol now includes an option to send a break
4229 rather than a ^C to the target in order to interrupt it. By default,
4230 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4232 * Remote protocol timeout
4234 The standard remote protocol includes a new variable `remotetimeout'
4235 that allows you to set the number of seconds before GDB gives up trying
4236 to read from the target. The default value is 2.
4238 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4240 By default GDB will automatically keep track of objects as they are
4241 loaded and unloaded by the dynamic linker. By using the command `set
4242 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4243 when shared library events occur, thus allowing you to set breakpoints
4244 in shared libraries which are explicitly loaded by the inferior.
4246 Note this feature does not work on hpux8. On hpux9 you must link
4247 /usr/lib/end.o into your program. This feature should work
4248 automatically on hpux10.
4250 * Irix 5.x hardware watchpoint support
4252 Irix 5 configurations now support the use of hardware watchpoints.
4254 * Mips protocol "SYN garbage limit"
4256 When debugging a Mips target using the `target mips' protocol, you
4257 may set the number of characters that GDB will ignore by setting
4258 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4259 every character. The default value is 1050.
4261 * Recording and replaying remote debug sessions
4263 If you set `remotelogfile' to the name of a file, gdb will write to it
4264 a recording of a remote debug session. This recording may then be
4265 replayed back to gdb using "gdbreplay". See gdbserver/README for
4266 details. This is useful when you have a problem with GDB while doing
4267 remote debugging; you can make a recording of the session and send it
4268 to someone else, who can then recreate the problem.
4270 * Speedups for remote debugging
4272 GDB includes speedups for downloading and stepping MIPS systems using
4273 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4274 and more efficient S-record downloading.
4276 * Memory use reductions and statistics collection
4278 GDB now uses less memory and reports statistics about memory usage.
4279 Try the `maint print statistics' command, for example.
4281 *** Changes in GDB-4.15:
4283 * Psymtabs for XCOFF
4285 The symbol reader for AIX GDB now uses partial symbol tables. This
4286 can greatly improve startup time, especially for large executables.
4288 * Remote targets use caching
4290 Remote targets now use a data cache to speed up communication with the
4291 remote side. The data cache could lead to incorrect results because
4292 it doesn't know about volatile variables, thus making it impossible to
4293 debug targets which use memory mapped I/O devices. `set remotecache
4294 off' turns the the data cache off.
4296 * Remote targets may have threads
4298 The standard remote protocol now includes support for multiple threads
4299 in the target system, using new protocol commands 'H' and 'T'. See
4300 gdb/remote.c for details.
4304 If GDB is configured with `--enable-netrom', then it will include
4305 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4306 acts as though it is a bank of ROM on the target board, but you can
4307 write into it over the network. GDB's support consists only of
4308 support for fast loading into the emulated ROM; to debug, you must use
4309 another protocol, such as standard remote protocol. The usual
4310 sequence is something like
4312 target nrom <netrom-hostname>
4314 target remote <netrom-hostname>:1235
4318 GDB now includes support for the Apple Macintosh, as a host only. It
4319 may be run as either an MPW tool or as a standalone application, and
4320 it can debug through the serial port. All the usual GDB commands are
4321 available, but to the target command, you must supply "serial" as the
4322 device type instead of "/dev/ttyXX". See mpw-README in the main
4323 directory for more information on how to build. The MPW configuration
4324 scripts */mpw-config.in support only a few targets, and only the
4325 mips-idt-ecoff target has been tested.
4329 GDB configuration now uses autoconf. This is not user-visible,
4330 but does simplify configuration and building.
4334 GDB now supports hpux10.
4336 *** Changes in GDB-4.14:
4338 * New native configurations
4340 x86 FreeBSD i[345]86-*-freebsd
4341 x86 NetBSD i[345]86-*-netbsd
4342 NS32k NetBSD ns32k-*-netbsd
4343 Sparc NetBSD sparc-*-netbsd
4347 A29K VxWorks a29k-*-vxworks
4348 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4349 CPU32 EST-300 emulator m68*-*-est*
4350 PowerPC ELF powerpc-*-elf
4353 * Alpha OSF/1 support for procfs
4355 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4356 possible to attach to running processes. As the mounting of the /proc
4357 filesystem is optional on the Alpha, GDB automatically determines
4358 the availability of /proc during startup. This can lead to problems
4359 if /proc is unmounted after GDB has been started.
4361 * Arguments to user-defined commands
4363 User commands may accept up to 10 arguments separated by whitespace.
4364 Arguments are accessed within the user command via $arg0..$arg9. A
4367 print $arg0 + $arg1 + $arg2
4369 To execute the command use:
4372 Defines the command "adder" which prints the sum of its three arguments.
4373 Note the arguments are text substitutions, so they may reference variables,
4374 use complex expressions, or even perform inferior function calls.
4376 * New `if' and `while' commands
4378 This makes it possible to write more sophisticated user-defined
4379 commands. Both commands take a single argument, which is the
4380 expression to evaluate, and must be followed by the commands to
4381 execute, one per line, if the expression is nonzero, the list being
4382 terminated by the word `end'. The `if' command list may include an
4383 `else' word, which causes the following commands to be executed only
4384 if the expression is zero.
4386 * Fortran source language mode
4388 GDB now includes partial support for Fortran 77. It will recognize
4389 Fortran programs and can evaluate a subset of Fortran expressions, but
4390 variables and functions may not be handled correctly. GDB will work
4391 with G77, but does not yet know much about symbols emitted by other
4394 * Better HPUX support
4396 Most debugging facilities now work on dynamic executables for HPPAs
4397 running hpux9 or later. You can attach to running dynamically linked
4398 processes, but by default the dynamic libraries will be read-only, so
4399 for instance you won't be able to put breakpoints in them. To change
4400 that behavior do the following before running the program:
4406 This will cause the libraries to be mapped private and read-write.
4407 To revert to the normal behavior, do this:
4413 You cannot set breakpoints or examine data in the library until after
4414 the library is loaded if the function/data symbols do not have
4417 GDB can now also read debug symbols produced by the HP C compiler on
4418 HPPAs (sorry, no C++, Fortran or 68k support).
4420 * Target byte order now dynamically selectable
4422 You can choose which byte order to use with a target system, via the
4423 commands "set endian big" and "set endian little", and you can see the
4424 current setting by using "show endian". You can also give the command
4425 "set endian auto", in which case GDB will use the byte order
4426 associated with the executable. Currently, only embedded MIPS
4427 configurations support dynamic selection of target byte order.
4429 * New DOS host serial code
4431 This version uses DPMI interrupts to handle buffered I/O, so you
4432 no longer need to run asynctsr when debugging boards connected to
4435 *** Changes in GDB-4.13:
4437 * New "complete" command
4439 This lists all the possible completions for the rest of the line, if it
4440 were to be given as a command itself. This is intended for use by emacs.
4442 * Trailing space optional in prompt
4444 "set prompt" no longer adds a space for you after the prompt you set. This
4445 allows you to set a prompt which ends in a space or one that does not.
4447 * Breakpoint hit counts
4449 "info break" now displays a count of the number of times the breakpoint
4450 has been hit. This is especially useful in conjunction with "ignore"; you
4451 can ignore a large number of breakpoint hits, look at the breakpoint info
4452 to see how many times the breakpoint was hit, then run again, ignoring one
4453 less than that number, and this will get you quickly to the last hit of
4456 * Ability to stop printing at NULL character
4458 "set print null-stop" will cause GDB to stop printing the characters of
4459 an array when the first NULL is encountered. This is useful when large
4460 arrays actually contain only short strings.
4462 * Shared library breakpoints
4464 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4465 breakpoints in shared libraries before the executable is run.
4467 * Hardware watchpoints
4469 There is a new hardware breakpoint for the watch command for sparclite
4470 targets. See gdb/sparclite/hw_breakpoint.note.
4472 Hardware watchpoints are also now supported under GNU/Linux.
4476 Annotations have been added. These are for use with graphical interfaces,
4477 and are still experimental. Currently only gdba.el uses these.
4479 * Improved Irix 5 support
4481 GDB now works properly with Irix 5.2.
4483 * Improved HPPA support
4485 GDB now works properly with the latest GCC and GAS.
4487 * New native configurations
4489 Sequent PTX4 i[34]86-sequent-ptx4
4490 HPPA running OSF/1 hppa*-*-osf*
4491 Atari TT running SVR4 m68*-*-sysv4*
4492 RS/6000 LynxOS rs6000-*-lynxos*
4496 OS/9000 i[34]86-*-os9k
4497 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4500 * Hitachi SH7000 and E7000-PC ICE support
4502 There is now support for communicating with the Hitachi E7000-PC ICE.
4503 This is available automatically when GDB is configured for the SH.
4507 As usual, a variety of small fixes and improvements, both generic
4508 and configuration-specific. See the ChangeLog for more detail.
4510 *** Changes in GDB-4.12:
4512 * Irix 5 is now supported
4516 GDB-4.12 on the HPPA has a number of changes which make it unable
4517 to debug the output from the currently released versions of GCC and
4518 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4519 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4520 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4523 *** Changes in GDB-4.11:
4525 * User visible changes:
4529 The "set remotedebug" option is now consistent between the mips remote
4530 target, remote targets using the gdb-specific protocol, UDI (AMD's
4531 debug protocol for the 29k) and the 88k bug monitor. It is now an
4532 integer specifying a debug level (normally 0 or 1, but 2 means more
4533 debugging info for the mips target).
4535 * DEC Alpha native support
4537 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4538 debug info, but GDB works fairly well with the DEC compiler and should
4539 work with a future GCC release. See the README file for a few
4540 Alpha-specific notes.
4542 * Preliminary thread implementation
4544 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4546 * LynxOS native and target support for 386
4548 This release has been hosted on LynxOS 2.2, and also can be configured
4549 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4552 * Improvements in C++ mangling/demangling.
4554 This release has much better g++ debugging, specifically in name
4555 mangling/demangling, virtual function calls, print virtual table,
4556 call methods, ...etc.
4558 *** Changes in GDB-4.10:
4560 * User visible changes:
4562 Remote debugging using the GDB-specific (`target remote') protocol now
4563 supports the `load' command. This is only useful if you have some
4564 other way of getting the stub to the target system, and you can put it
4565 somewhere in memory where it won't get clobbered by the download.
4567 Filename completion now works.
4569 When run under emacs mode, the "info line" command now causes the
4570 arrow to point to the line specified. Also, "info line" prints
4571 addresses in symbolic form (as well as hex).
4573 All vxworks based targets now support a user settable option, called
4574 vxworks-timeout. This option represents the number of seconds gdb
4575 should wait for responses to rpc's. You might want to use this if
4576 your vxworks target is, perhaps, a slow software simulator or happens
4577 to be on the far side of a thin network line.
4581 This release contains support for using a DEC alpha as a GDB host for
4582 cross debugging. Native alpha debugging is not supported yet.
4585 *** Changes in GDB-4.9:
4589 This is the first GDB release which is accompanied by a matching testsuite.
4590 The testsuite requires installation of dejagnu, which should be available
4591 via ftp from most sites that carry GNU software.
4595 'Cfront' style demangling has had its name changed to 'ARM' style, to
4596 emphasize that it was written from the specifications in the C++ Annotated
4597 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4598 disclaimers, it still generated too much confusion with users attempting to
4599 use gdb with AT&T cfront.
4603 GDB now uses a standard remote interface to a simulator library.
4604 So far, the library contains simulators for the Zilog Z8001/2, the
4605 Hitachi H8/300, H8/500 and Super-H.
4607 * New targets supported
4609 H8/300 simulator h8300-hitachi-hms or h8300hms
4610 H8/500 simulator h8500-hitachi-hms or h8500hms
4611 SH simulator sh-hitachi-hms or sh
4612 Z8000 simulator z8k-zilog-none or z8ksim
4613 IDT MIPS board over serial line mips-idt-ecoff
4615 Cross-debugging to GO32 targets is supported. It requires a custom
4616 version of the i386-stub.c module which is integrated with the
4617 GO32 memory extender.
4619 * New remote protocols
4621 MIPS remote debugging protocol.
4623 * New source languages supported
4625 This version includes preliminary support for Chill, a Pascal like language
4626 used by telecommunications companies. Chill support is also being integrated
4627 into the GNU compiler, but we don't know when it will be publically available.
4630 *** Changes in GDB-4.8:
4632 * HP Precision Architecture supported
4634 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4635 version of this support was available as a set of patches from the
4636 University of Utah. GDB does not support debugging of programs
4637 compiled with the HP compiler, because HP will not document their file
4638 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4639 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4641 Many problems in the preliminary version have been fixed.
4643 * Faster and better demangling
4645 We have improved template demangling and fixed numerous bugs in the GNU style
4646 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4647 character types (wchar_t) are now supported. Demangling of each symbol is now
4648 only done once, and is cached when the symbol table for a file is read in.
4649 This results in a small increase in memory usage for C programs, a moderate
4650 increase in memory usage for C++ programs, and a fantastic speedup in
4653 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4654 from the specifications in the Annotated Reference Manual, which AT&T's
4655 compiler does not actually implement.
4657 * G++ multiple inheritance compiler problem
4659 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4660 inheritance lattices was reworked to properly discover ambiguities. We
4661 recently found an example which causes this new algorithm to fail in a
4662 very subtle way, producing bad debug information for those classes.
4663 The file 'gcc.patch' (in this directory) can be applied to gcc to
4664 circumvent the problem. A future GCC release will contain a complete
4667 The previous G++ debug info problem (mentioned below for the gdb-4.7
4668 release) is fixed in gcc version 2.3.2.
4670 * Improved configure script
4672 The `configure' script will now attempt to guess your system type if
4673 you don't supply a host system type. The old scheme of supplying a
4674 host system triplet is preferable over using this. All the magic is
4675 done in the new `config.guess' script. Examine it for details.
4677 We have also brought our configure script much more in line with the FSF's
4678 version. It now supports the --with-xxx options. In particular,
4679 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4680 The resulting GDB will not be able to read arbitrary object file formats --
4681 only the format ``expected'' to be used on the configured target system.
4682 We hope to make this the default in a future release.
4684 * Documentation improvements
4686 There's new internal documentation on how to modify GDB, and how to
4687 produce clean changes to the code. We implore people to read it
4688 before submitting changes.
4690 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4691 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4692 `info' files are also provided. To build `info' files from scratch,
4693 you will need the latest `makeinfo' release, which will be available in
4694 a future texinfo-X.Y release.
4696 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4697 We're not sure exactly which versions have this problem, but it has
4698 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4699 or better. If that isn't possible, there is a patch in
4700 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4701 around this problem.
4705 GDB now supports array constants that can be used in expressions typed in by
4706 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4707 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4710 The new directory `gdb/sparclite' contains a program that demonstrates
4711 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4713 * New native hosts supported
4715 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4716 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4718 * New targets supported
4720 AMD 29k family via UDI a29k-amd-udi or udi29k
4722 * New file formats supported
4724 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4725 HPUX core files, and SCO 3.2v2 core files.
4729 Attaching to processes now works again; thanks for the many bug reports.
4731 We have also stomped on a bunch of core dumps caused by
4732 printf_filtered("%s") problems.
4734 We eliminated a copyright problem on the rpc and ptrace header files
4735 for VxWorks, which was discovered at the last minute during the 4.7
4736 release. You should now be able to build a VxWorks GDB.
4738 You can now interrupt gdb while an attached process is running. This
4739 will cause the attached process to stop, and give control back to GDB.
4741 We fixed problems caused by using too many file descriptors
4742 for reading symbols from object files and libraries. This was
4743 especially a problem for programs that used many (~100) shared
4746 The `step' command now only enters a subroutine if there is line number
4747 information for the subroutine. Otherwise it acts like the `next'
4748 command. Previously, `step' would enter subroutines if there was
4749 any debugging information about the routine. This avoids problems
4750 when using `cc -g1' on MIPS machines.
4752 * Internal improvements
4754 GDB's internal interfaces have been improved to make it easier to support
4755 debugging of multiple languages in the future.
4757 GDB now uses a common structure for symbol information internally.
4758 Minimal symbols (derived from linkage symbols in object files), partial
4759 symbols (from a quick scan of debug information), and full symbols
4760 contain a common subset of information, making it easier to write
4761 shared code that handles any of them.
4763 * New command line options
4765 We now accept --silent as an alias for --quiet.
4769 The memory-mapped-malloc library is now licensed under the GNU Library
4770 General Public License.
4772 *** Changes in GDB-4.7:
4774 * Host/native/target split
4776 GDB has had some major internal surgery to untangle the support for
4777 hosts and remote targets. Now, when you configure GDB for a remote
4778 target, it will no longer load in all of the support for debugging
4779 local programs on the host. When fully completed and tested, this will
4780 ensure that arbitrary host/target combinations are possible.
4782 The primary conceptual shift is to separate the non-portable code in
4783 GDB into three categories. Host specific code is required any time GDB
4784 is compiled on that host, regardless of the target. Target specific
4785 code relates to the peculiarities of the target, but can be compiled on
4786 any host. Native specific code is everything else: it can only be
4787 built when the host and target are the same system. Child process
4788 handling and core file support are two common `native' examples.
4790 GDB's use of /proc for controlling Unix child processes is now cleaner.
4791 It has been split out into a single module under the `target_ops' vector,
4792 plus two native-dependent functions for each system that uses /proc.
4794 * New hosts supported
4796 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4797 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4798 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4800 * New targets supported
4802 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4803 68030 and CPU32 m68030-*-*, m68332-*-*
4805 * New native hosts supported
4807 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4808 (386bsd is not well tested yet)
4809 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4811 * New file formats supported
4813 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4814 supports reading of `a.out.adobe' object files, which are an a.out
4815 format extended with minimal information about multiple sections.
4819 `show copying' is the same as the old `info copying'.
4820 `show warranty' is the same as `info warrantee'.
4821 These were renamed for consistency. The old commands continue to work.
4823 `info handle' is a new alias for `info signals'.
4825 You can now define pre-command hooks, which attach arbitrary command
4826 scripts to any command. The commands in the hook will be executed
4827 prior to the user's command. You can also create a hook which will be
4828 executed whenever the program stops. See gdb.texinfo.
4832 We now deal with Cfront style name mangling, and can even extract type
4833 info from mangled symbols. GDB can automatically figure out which
4834 symbol mangling style your C++ compiler uses.
4836 Calling of methods and virtual functions has been improved as well.
4840 The crash that occured when debugging Sun Ansi-C compiled binaries is
4841 fixed. This was due to mishandling of the extra N_SO stabs output
4844 We also finally got Ultrix 4.2 running in house, and fixed core file
4845 support, with help from a dozen people on the net.
4847 John M. Farrell discovered that the reason that single-stepping was so
4848 slow on all of the Mips based platforms (primarily SGI and DEC) was
4849 that we were trying to demangle and lookup a symbol used for internal
4850 purposes on every instruction that was being stepped through. Changing
4851 the name of that symbol so that it couldn't be mistaken for a C++
4852 mangled symbol sped things up a great deal.
4854 Rich Pixley sped up symbol lookups in general by getting much smarter
4855 about when C++ symbol mangling is necessary. This should make symbol
4856 completion (TAB on the command line) much faster. It's not as fast as
4857 we'd like, but it's significantly faster than gdb-4.6.
4861 A new user controllable variable 'call_scratch_address' can
4862 specify the location of a scratch area to be used when GDB
4863 calls a function in the target. This is necessary because the
4864 usual method of putting the scratch area on the stack does not work
4865 in systems that have separate instruction and data spaces.
4867 We integrated changes to support the 29k UDI (Universal Debugger
4868 Interface), but discovered at the last minute that we didn't have all
4869 of the appropriate copyright paperwork. We are working with AMD to
4870 resolve this, and hope to have it available soon.
4874 We have sped up the remote serial line protocol, especially for targets
4875 with lots of registers. It now supports a new `expedited status' ('T')
4876 message which can be used in place of the existing 'S' status message.
4877 This allows the remote stub to send only the registers that GDB
4878 needs to make a quick decision about single-stepping or conditional
4879 breakpoints, eliminating the need to fetch the entire register set for
4880 each instruction being stepped through.
4882 The GDB remote serial protocol now implements a write-through cache for
4883 registers, only re-reading the registers if the target has run.
4885 There is also a new remote serial stub for SPARC processors. You can
4886 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4887 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4888 processor with a serial port.
4892 Configure.in files have become much easier to read and modify. A new
4893 `table driven' format makes it more obvious what configurations are
4894 supported, and what files each one uses.
4898 There is a new opcodes library which will eventually contain all of the
4899 disassembly routines and opcode tables. At present, it only contains
4900 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4901 disassembler (binutils/objdump) to share these routines.
4903 The libiberty library is now copylefted under the GNU Library General
4904 Public License. This allows more liberal use, and was done so libg++
4905 can use it. This makes no difference to GDB, since the Library License
4906 grants all the rights from the General Public License.
4910 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4911 reference to the stabs symbol info used by the debugger. It is (as far
4912 as we know) the only published document on this fascinating topic. We
4913 encourage you to read it, compare it to the stabs information on your
4914 system, and send improvements on the document in general (to
4915 bug-gdb@prep.ai.mit.edu).
4917 And, of course, many bugs have been fixed.
4920 *** Changes in GDB-4.6:
4922 * Better support for C++ function names
4924 GDB now accepts as input the "demangled form" of C++ overloaded function
4925 names and member function names, and can do command completion on such names
4926 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4927 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4928 Make use of command completion, it is your friend.
4930 GDB also now accepts a variety of C++ mangled symbol formats. They are
4931 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4932 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4933 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4934 for the list of formats.
4936 * G++ symbol mangling problem
4938 Recent versions of gcc have a bug in how they emit debugging information for
4939 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4940 directory) can be applied to gcc to fix the problem. Alternatively, if you
4941 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4942 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4943 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4946 * New 'maintenance' command
4948 All of the commands related to hacking GDB internals have been moved out of
4949 the main command set, and now live behind the 'maintenance' command. This
4950 can also be abbreviated as 'mt'. The following changes were made:
4952 dump-me -> maintenance dump-me
4953 info all-breakpoints -> maintenance info breakpoints
4954 printmsyms -> maintenance print msyms
4955 printobjfiles -> maintenance print objfiles
4956 printpsyms -> maintenance print psymbols
4957 printsyms -> maintenance print symbols
4959 The following commands are new:
4961 maintenance demangle Call internal GDB demangler routine to
4962 demangle a C++ link name and prints the result.
4963 maintenance print type Print a type chain for a given symbol
4965 * Change to .gdbinit file processing
4967 We now read the $HOME/.gdbinit file before processing the argv arguments
4968 (e.g. reading symbol files or core files). This allows global parameters to
4969 be set, which will apply during the symbol reading. The ./.gdbinit is still
4970 read after argv processing.
4972 * New hosts supported
4974 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4976 GNU/Linux support i386-unknown-linux or linux
4978 We are also including code to support the HP/PA running BSD and HPUX. This
4979 is almost guaranteed not to work, as we didn't have time to test or build it
4980 for this release. We are including it so that the more adventurous (or
4981 masochistic) of you can play with it. We also had major problems with the
4982 fact that the compiler that we got from HP doesn't support the -g option.
4985 * New targets supported
4987 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4989 * More smarts about finding #include files
4991 GDB now remembers the compilation directory for all include files, and for
4992 all files from which C is generated (like yacc and lex sources). This
4993 greatly improves GDB's ability to find yacc/lex sources, and include files,
4994 especially if you are debugging your program from a directory different from
4995 the one that contains your sources.
4997 We also fixed a bug which caused difficulty with listing and setting
4998 breakpoints in include files which contain C code. (In the past, you had to
4999 try twice in order to list an include file that you hadn't looked at before.)
5001 * Interesting infernals change
5003 GDB now deals with arbitrary numbers of sections, where the symbols for each
5004 section must be relocated relative to that section's landing place in the
5005 target's address space. This work was needed to support ELF with embedded
5006 stabs used by Solaris-2.0.
5008 * Bug fixes (of course!)
5010 There have been loads of fixes for the following things:
5011 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5012 i960, stabs, DOS(GO32), procfs, etc...
5014 See the ChangeLog for details.
5016 *** Changes in GDB-4.5:
5018 * New machines supported (host and target)
5020 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5022 SGI Irix-4.x mips-sgi-irix4 or iris4
5024 * New malloc package
5026 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5027 Mmalloc is capable of handling mutiple heaps of memory. It is also
5028 capable of saving a heap to a file, and then mapping it back in later.
5029 This can be used to greatly speedup the startup of GDB by using a
5030 pre-parsed symbol table which lives in a mmalloc managed heap. For
5031 more details, please read mmalloc/mmalloc.texi.
5035 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5036 'help info proc' for details.
5038 * MIPS ecoff symbol table format
5040 The code that reads MIPS symbol table format is now supported on all hosts.
5041 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5044 * File name changes for MS-DOS
5046 Many files in the config directories have been renamed to make it easier to
5047 support GDB on MS-DOSe systems (which have very restrictive file name
5048 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5049 environment) is close to working but has some remaining problems. Note
5050 that debugging of DOS programs is not supported, due to limitations
5051 in the ``operating system'', but it can be used to host cross-debugging.
5053 * Cross byte order fixes
5055 Many fixes have been made to support cross debugging of Sparc and MIPS
5056 targets from hosts whose byte order differs.
5058 * New -mapped and -readnow options
5060 If memory-mapped files are available on your system through the 'mmap'
5061 system call, you can use the -mapped option on the `file' or
5062 `symbol-file' commands to cause GDB to write the symbols from your
5063 program into a reusable file. If the program you are debugging is
5064 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5065 Future GDB debugging sessions will notice the presence of this file,
5066 and will quickly map in symbol information from it, rather than reading
5067 the symbol table from the executable program. Using the '-mapped'
5068 option in a GDB `file' or `symbol-file' command has the same effect as
5069 starting GDB with the '-mapped' command-line option.
5071 You can cause GDB to read the entire symbol table immediately by using
5072 the '-readnow' option with any of the commands that load symbol table
5073 information (or on the GDB command line). This makes the command
5074 slower, but makes future operations faster.
5076 The -mapped and -readnow options are typically combined in order to
5077 build a `fred.syms' file that contains complete symbol information.
5078 A simple GDB invocation to do nothing but build a `.syms' file for future
5081 gdb -batch -nx -mapped -readnow programname
5083 The `.syms' file is specific to the host machine on which GDB is run.
5084 It holds an exact image of GDB's internal symbol table. It cannot be
5085 shared across multiple host platforms.
5087 * longjmp() handling
5089 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5090 siglongjmp() without losing control. This feature has not yet been ported to
5091 all systems. It currently works on many 386 platforms, all MIPS-based
5092 platforms (SGI, DECstation, etc), and Sun3/4.
5096 Preliminary work has been put in to support the new Solaris OS from Sun. At
5097 this time, it can control and debug processes, but it is not capable of
5102 As always, many many bug fixes. The major areas were with g++, and mipsread.
5103 People using the MIPS-based platforms should experience fewer mysterious
5104 crashes and trashed symbol tables.
5106 *** Changes in GDB-4.4:
5108 * New machines supported (host and target)
5110 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5112 BSD Reno on Vax vax-dec-bsd
5113 Ultrix on Vax vax-dec-ultrix
5115 * New machines supported (target)
5117 AMD 29000 embedded, using EBMON a29k-none-none
5121 GDB continues to improve its handling of C++. `References' work better.
5122 The demangler has also been improved, and now deals with symbols mangled as
5123 per the Annotated C++ Reference Guide.
5125 GDB also now handles `stabs' symbol information embedded in MIPS
5126 `ecoff' symbol tables. Since the ecoff format was not easily
5127 extensible to handle new languages such as C++, this appeared to be a
5128 good way to put C++ debugging info into MIPS binaries. This option
5129 will be supported in the GNU C compiler, version 2, when it is
5132 * New features for SVR4
5134 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5135 shared libraries. Debugging dynamically linked programs should present
5136 only minor differences from debugging statically linked programs.
5138 The `info proc' command will print out information about any process
5139 on an SVR4 system (including the one you are debugging). At the moment,
5140 it prints the address mappings of the process.
5142 If you bring up GDB on another SVR4 system, please send mail to
5143 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5145 * Better dynamic linking support in SunOS
5147 Reading symbols from shared libraries which contain debugging symbols
5148 now works properly. However, there remain issues such as automatic
5149 skipping of `transfer vector' code during function calls, which
5150 make it harder to debug code in a shared library, than to debug the
5151 same code linked statically.
5155 GDB is now using the latest `getopt' routines from the FSF. This
5156 version accepts the -- prefix for options with long names. GDB will
5157 continue to accept the old forms (-option and +option) as well.
5158 Various single letter abbreviations for options have been explicity
5159 added to the option table so that they won't get overshadowed in the
5160 future by other options that begin with the same letter.
5164 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5165 Many assorted bugs have been handled. Many more remain to be handled.
5166 See the various ChangeLog files (primarily in gdb and bfd) for details.
5169 *** Changes in GDB-4.3:
5171 * New machines supported (host and target)
5173 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5174 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5175 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5177 * Almost SCO Unix support
5179 We had hoped to support:
5180 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5181 (except for core file support), but we discovered very late in the release
5182 that it has problems with process groups that render gdb unusable. Sorry
5183 about that. I encourage people to fix it and post the fixes.
5185 * Preliminary ELF and DWARF support
5187 GDB can read ELF object files on System V Release 4, and can handle
5188 debugging records for C, in DWARF format, in ELF files. This support
5189 is preliminary. If you bring up GDB on another SVR4 system, please
5190 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5195 GDB now uses the latest `readline' library. One user-visible change
5196 is that two tabs will list possible command completions, which previously
5197 required typing M-? (meta-question mark, or ESC ?).
5201 The `stepi' bug that many of you noticed has been squashed.
5202 Many bugs in C++ have been handled. Many more remain to be handled.
5203 See the various ChangeLog files (primarily in gdb and bfd) for details.
5205 * State of the MIPS world (in case you wondered):
5207 GDB can understand the symbol tables emitted by the compilers
5208 supplied by most vendors of MIPS-based machines, including DEC. These
5209 symbol tables are in a format that essentially nobody else uses.
5211 Some versions of gcc come with an assembler post-processor called
5212 mips-tfile. This program is required if you want to do source-level
5213 debugging of gcc-compiled programs. I believe FSF does not ship
5214 mips-tfile with gcc version 1, but it will eventually come with gcc
5217 Debugging of g++ output remains a problem. g++ version 1.xx does not
5218 really support it at all. (If you're lucky, you should be able to get
5219 line numbers and stack traces to work, but no parameters or local
5220 variables.) With some work it should be possible to improve the
5223 When gcc version 2 is released, you will have somewhat better luck.
5224 However, even then you will get confusing results for inheritance and
5227 We will eventually provide full debugging of g++ output on
5228 DECstations. This will probably involve some kind of stabs-in-ecoff
5229 encapulation, but the details have not been worked out yet.
5232 *** Changes in GDB-4.2:
5234 * Improved configuration
5236 Only one copy of `configure' exists now, and it is not self-modifying.
5237 Porting BFD is simpler.
5241 The `step' and `next' commands now only stop at the first instruction
5242 of a source line. This prevents the multiple stops that used to occur
5243 in switch statements, for-loops, etc. `Step' continues to stop if a
5244 function that has debugging information is called within the line.
5248 Lots of small bugs fixed. More remain.
5250 * New host supported (not target)
5252 Intel 386 PC clone running Mach i386-none-mach
5255 *** Changes in GDB-4.1:
5257 * Multiple source language support
5259 GDB now has internal scaffolding to handle several source languages.
5260 It determines the type of each source file from its filename extension,
5261 and will switch expression parsing and number formatting to match the
5262 language of the function in the currently selected stack frame.
5263 You can also specifically set the language to be used, with
5264 `set language c' or `set language modula-2'.
5268 GDB now has preliminary support for the GNU Modula-2 compiler,
5269 currently under development at the State University of New York at
5270 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5271 continue through the fall of 1991 and into 1992.
5273 Other Modula-2 compilers are currently not supported, and attempting to
5274 debug programs compiled with them will likely result in an error as the
5275 symbol table is read. Feel free to work on it, though!
5277 There are hooks in GDB for strict type checking and range checking,
5278 in the `Modula-2 philosophy', but they do not currently work.
5282 GDB can now write to executable and core files (e.g. patch
5283 a variable's value). You must turn this switch on, specify
5284 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5285 by assigning a new value to a variable. Modifications take
5288 * Automatic SunOS shared library reading
5290 When you run your program, GDB automatically determines where its
5291 shared libraries (if any) have been loaded, and reads their symbols.
5292 The `share' command is no longer needed. This also works when
5293 examining core files.
5297 You can specify the number of lines that the `list' command shows.
5300 * New machines supported (host and target)
5302 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5303 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5304 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5306 * New hosts supported (not targets)
5308 IBM RT/PC: romp-ibm-aix or rtpc
5310 * New targets supported (not hosts)
5312 AMD 29000 embedded with COFF a29k-none-coff
5313 AMD 29000 embedded with a.out a29k-none-aout
5314 Ultracomputer remote kernel debug a29k-nyu-kern
5316 * New remote interfaces
5322 *** Changes in GDB-4.0:
5326 Wide output is wrapped at good places to make the output more readable.
5328 Gdb now supports cross-debugging from a host machine of one type to a
5329 target machine of another type. Communication with the target system
5330 is over serial lines. The ``target'' command handles connecting to the
5331 remote system; the ``load'' command will download a program into the
5332 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5333 also supports debugging of realtime processes running under VxWorks,
5334 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5335 stub on the target system.
5337 New CPUs supported include the AMD 29000 and Intel 960.
5339 GDB now reads object files and symbol tables via a ``binary file''
5340 library, which allows a single copy of GDB to debug programs of multiple
5341 object file types such as a.out and coff.
5343 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5344 refcard.dvi and refcard.ps are available to format it).
5347 * Control-Variable user interface simplified
5349 All variables that control the operation of the debugger can be set
5350 by the ``set'' command, and displayed by the ``show'' command.
5352 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5353 ``Show prompt'' produces the response:
5354 Gdb's prompt is new-gdb=>.
5356 What follows are the NEW set commands. The command ``help set'' will
5357 print a complete list of old and new set commands. ``help set FOO''
5358 will give a longer description of the variable FOO. ``show'' will show
5359 all of the variable descriptions and their current settings.
5361 confirm on/off: Enables warning questions for operations that are
5362 hard to recover from, e.g. rerunning the program while
5363 it is already running. Default is ON.
5365 editing on/off: Enables EMACS style command line editing
5366 of input. Previous lines can be recalled with
5367 control-P, the current line can be edited with control-B,
5368 you can search for commands with control-R, etc.
5371 history filename NAME: NAME is where the gdb command history
5372 will be stored. The default is .gdb_history,
5373 or the value of the environment variable
5376 history size N: The size, in commands, of the command history. The
5377 default is 256, or the value of the environment variable
5380 history save on/off: If this value is set to ON, the history file will
5381 be saved after exiting gdb. If set to OFF, the
5382 file will not be saved. The default is OFF.
5384 history expansion on/off: If this value is set to ON, then csh-like
5385 history expansion will be performed on
5386 command line input. The default is OFF.
5388 radix N: Sets the default radix for input and output. It can be set
5389 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5390 in the current radix, so "set radix 10" is always a no-op.
5392 height N: This integer value is the number of lines on a page. Default
5393 is 24, the current `stty rows'' setting, or the ``li#''
5394 setting from the termcap entry matching the environment
5397 width N: This integer value is the number of characters on a line.
5398 Default is 80, the current `stty cols'' setting, or the ``co#''
5399 setting from the termcap entry matching the environment
5402 Note: ``set screensize'' is obsolete. Use ``set height'' and
5403 ``set width'' instead.
5405 print address on/off: Print memory addresses in various command displays,
5406 such as stack traces and structure values. Gdb looks
5407 more ``symbolic'' if you turn this off; it looks more
5408 ``machine level'' with it on. Default is ON.
5410 print array on/off: Prettyprint arrays. New convenient format! Default
5413 print demangle on/off: Print C++ symbols in "source" form if on,
5416 print asm-demangle on/off: Same, for assembler level printouts
5419 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5422 * Support for Epoch Environment.
5424 The epoch environment is a version of Emacs v18 with windowing. One
5425 new command, ``inspect'', is identical to ``print'', except that if you
5426 are running in the epoch environment, the value is printed in its own
5430 * Support for Shared Libraries
5432 GDB can now debug programs and core files that use SunOS shared libraries.
5433 Symbols from a shared library cannot be referenced
5434 before the shared library has been linked with the program (this
5435 happens after you type ``run'' and before the function main() is entered).
5436 At any time after this linking (including when examining core files
5437 from dynamically linked programs), gdb reads the symbols from each
5438 shared library when you type the ``sharedlibrary'' command.
5439 It can be abbreviated ``share''.
5441 sharedlibrary REGEXP: Load shared object library symbols for files
5442 matching a unix regular expression. No argument
5443 indicates to load symbols for all shared libraries.
5445 info sharedlibrary: Status of loaded shared libraries.
5450 A watchpoint stops execution of a program whenever the value of an
5451 expression changes. Checking for this slows down execution
5452 tremendously whenever you are in the scope of the expression, but is
5453 quite useful for catching tough ``bit-spreader'' or pointer misuse
5454 problems. Some machines such as the 386 have hardware for doing this
5455 more quickly, and future versions of gdb will use this hardware.
5457 watch EXP: Set a watchpoint (breakpoint) for an expression.
5459 info watchpoints: Information about your watchpoints.
5461 delete N: Deletes watchpoint number N (same as breakpoints).
5462 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5463 enable N: Re-enables watchpoint number N (same as breakpoints).
5466 * C++ multiple inheritance
5468 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5471 * C++ exception handling
5473 Gdb now supports limited C++ exception handling. Besides the existing
5474 ability to breakpoint on an exception handler, gdb can breakpoint on
5475 the raising of an exception (before the stack is peeled back to the
5478 catch FOO: If there is a FOO exception handler in the dynamic scope,
5479 set a breakpoint to catch exceptions which may be raised there.
5480 Multiple exceptions (``catch foo bar baz'') may be caught.
5482 info catch: Lists all exceptions which may be caught in the
5483 current stack frame.
5486 * Minor command changes
5488 The command ``call func (arg, arg, ...)'' now acts like the print
5489 command, except it does not print or save a value if the function's result
5490 is void. This is similar to dbx usage.
5492 The ``up'' and ``down'' commands now always print the frame they end up
5493 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5494 frames without printing.
5496 * New directory command
5498 'dir' now adds directories to the FRONT of the source search path.
5499 The path starts off empty. Source files that contain debug information
5500 about the directory in which they were compiled can be found even
5501 with an empty path; Sun CC and GCC include this information. If GDB can't
5502 find your source file in the current directory, type "dir .".
5504 * Configuring GDB for compilation
5506 For normal use, type ``./configure host''. See README or gdb.texinfo
5509 GDB now handles cross debugging. If you are remotely debugging between
5510 two different machines, type ``./configure host -target=targ''.
5511 Host is the machine where GDB will run; targ is the machine
5512 where the program that you are debugging will run.