1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.5
6 * New native configurations
8 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
9 FreeBSD/powerpc powerpc*-*-freebsd
13 ARM AArch64 aarch64*-*-elf
14 ARM AArch64 GNU/Linux aarch64*-*-linux
15 Lynx 178 PowerPC powerpc-*-lynx*178
16 x86_64/Cygwin x86_64-*-cygwin*
18 * If the configured location of system.gdbinit file (as given by the
19 --with-system-gdbinit option at configure time) is in the
20 data-directory (as specified by --with-gdb-datadir at configure
21 time) or in one of its subdirectories, then GDB will look for the
22 system-wide init file in the directory specified by the
23 --data-directory command-line option.
25 * New command line options:
27 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
28 other initialization files, unlike -nx which disables all of them.
30 * Removed command line options
32 -epoch This was used by the gdb mode in Epoch, an ancient fork of
35 * The 'ptype' and 'whatis' commands now accept an argument to control
38 * 'info proc' now works on some core files.
42 ** Vectors can be created with gdb.Type.vector.
44 ** Python's atexit.register now works in GDB.
46 ** Types can be pretty-printed via a Python API.
48 ** Python 3 is now supported (in addition to Python 2.4 or later)
50 ** New class gdb.Architecture exposes GDB's internal representation
51 of architecture in the Python API.
53 ** New method Frame.architecture returns the gdb.Architecture object
54 corresponding to the frame's architecture.
56 * New Python-based convenience functions:
58 ** $_memeq(buf1, buf2, length)
59 ** $_streq(str1, str2)
61 ** $_regex(str, regex)
63 * The 'cd' command now defaults to using '~' (the home directory) if not
66 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
67 default for GCC since November 2000.
69 * The command 'forward-search' can now be abbreviated as 'fo'.
71 * The command 'info tracepoints' can now display 'installed on target'
72 or 'not installed on target' for each non-pending location of tracepoint.
74 * New configure options
76 --enable-libmcheck/--disable-libmcheck
77 By default, development versions are built with -lmcheck on hosts
78 that support it, in order to help track memory corruption issues.
79 Release versions, on the other hand, are built without -lmcheck
80 by default. The --enable-libmcheck/--disable-libmcheck configure
81 options allow the user to override that default.
83 * New commands (for set/show, see "New options" below)
86 Catch signals. This is similar to "handle", but allows commands and
87 conditions to be attached.
90 List the BFDs known to GDB.
92 python-interactive [command]
94 Start a Python interactive prompt, or evaluate the optional command
95 and print the result of expressions.
98 "py" is a new alias for "python".
100 enable type-printer [name]...
101 disable type-printer [name]...
102 Enable or disable type printers.
104 set debug notification
105 show debug notification
106 Control display of debugging info for async remote notification.
110 ** For the Renesas Super-H architecture, the "regs" command has been removed
111 (has been deprecated in GDB 7.5), and "info all-registers" should be used
116 set print type methods (on|off)
117 show print type methods
118 Control whether method declarations are displayed by "ptype".
119 The default is to show them.
121 set print type typedefs (on|off)
122 show print type typedefs
123 Control whether typedef definitions are displayed by "ptype".
124 The default is to show them.
126 set filename-display basename|relative|absolute
127 show filename-display
128 Control the way in which filenames is displayed.
129 The default is "relative", which preserves previous behavior.
133 ** Command parameter changes are now notified using new async record
134 "=cmd-param-changed".
135 ** Trace frame changes caused by command "tfind" are now notified using
136 new async record "=traceframe-changed".
137 ** The creation, deletion and modification of trace state variables
138 are now notified using new async records "=tsv-created",
139 "=tsv-deleted" and "=tsv-modified".
140 ** The start and stop of process record are now notified using new
141 async record "=record-started" and "=record-stopped".
142 ** Memory changes are now notified using new async record
144 ** The data-disassemble command response will include a "fullname" field
145 containing the absolute file name when GDB can determine it and source
147 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
148 command, to allow pattern filling of memory areas.
149 ** New commands "-catch-load"/"-catch-unload" added for intercepting
150 library load/unload events.
151 ** The response to breakpoint commands and breakpoint async records
152 includes an "installed" field containing a boolean state about each
153 non-pending tracepoint location is whether installed on target or not.
154 ** Output of the "-trace-status" command includes a "trace-file" field
155 containing the name of the trace file being examined. This field is
156 optional, and only present when examining a trace file.
158 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
159 You must have the LZMA library available when configuring GDB for this
160 feature to be enabled. For more information, see:
161 http://fedoraproject.org/wiki/Features/MiniDebugInfo
163 *** Changes in GDB 7.5
165 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
166 for more x32 ABI info.
168 * GDB now supports access to MIPS DSP registers on Linux targets.
170 * GDB now supports debugging microMIPS binaries.
172 * The "info os" command on GNU/Linux can now display information on
173 several new classes of objects managed by the operating system:
174 "info os procgroups" lists process groups
175 "info os files" lists file descriptors
176 "info os sockets" lists internet-domain sockets
177 "info os shm" lists shared-memory regions
178 "info os semaphores" lists semaphores
179 "info os msg" lists message queues
180 "info os modules" lists loaded kernel modules
182 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
183 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
184 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
185 options and inspect the probe arguments using the new $_probe_arg family
186 of convenience variables. You can obtain more information about SystemTap
187 in <http://sourceware.org/systemtap/>.
189 * GDB now supports reversible debugging on ARM, it allows you to
190 debug basic ARM and THUMB instructions, and provides
191 record/replay support.
193 * The option "symbol-reloading" has been deleted as it is no longer used.
197 ** GDB commands implemented in Python can now be put in command class
200 ** The "maint set python print-stack on|off" is now deleted.
202 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
203 apply "flag enum"-style pretty-printing to any enum.
205 ** gdb.lookup_symbol can now work when there is no current frame.
207 ** gdb.Symbol now has a 'line' attribute, holding the line number in
208 the source at which the symbol was defined.
210 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
211 method 'value'. The former indicates whether the symbol needs a
212 frame in order to compute its value, and the latter computes the
215 ** A new method 'referenced_value' on gdb.Value objects which can
216 dereference pointer as well as C++ reference values.
218 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
219 which return the global and static blocks (as gdb.Block objects),
220 of the underlying symbol table, respectively.
222 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
223 object associated with a PC value.
225 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
226 of the address range occupied by code for the current source line.
228 * Go language support.
229 GDB now supports debugging programs written in the Go programming
232 * GDBserver now supports stdio connections.
233 E.g. (gdb) target remote | ssh myhost gdbserver - hello
235 * The binary "gdbtui" can no longer be built or installed.
236 Use "gdb -tui" instead.
238 * GDB will now print "flag" enums specially. A flag enum is one where
239 all the enumerator values have no bits in common when pairwise
240 "and"ed. When printing a value whose type is a flag enum, GDB will
241 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
242 (gdb) print (enum E) 3
245 * The filename part of a linespec will now match trailing components
246 of a source file name. For example, "break gcc/expr.c:1000" will
247 now set a breakpoint in build/gcc/expr.c, but not
250 * The "info proc" and "generate-core-file" commands will now also
251 work on remote targets connected to GDBserver on Linux.
253 * The command "info catch" has been removed. It has been disabled
256 * The "catch exception" and "catch assert" commands now accept
257 a condition at the end of the command, much like the "break"
258 command does. For instance:
260 (gdb) catch exception Constraint_Error if Barrier = True
262 Previously, it was possible to add a condition to such catchpoints,
263 but it had to be done as a second step, after the catchpoint had been
264 created, using the "condition" command.
266 * The "info static-tracepoint-marker" command will now also work on
267 native Linux targets with in-process agent.
269 * GDB can now set breakpoints on inlined functions.
271 * The .gdb_index section has been updated to include symbols for
272 inlined functions. GDB will ignore older .gdb_index sections by
273 default, which could cause symbol files to be loaded more slowly
274 until their .gdb_index sections can be recreated. The new command
275 "set use-deprecated-index-sections on" will cause GDB to use any older
276 .gdb_index sections it finds. This will restore performance, but the
277 ability to set breakpoints on inlined functions will be lost in symbol
278 files with older .gdb_index sections.
280 The .gdb_index section has also been updated to record more information
281 about each symbol. This speeds up the "info variables", "info functions"
282 and "info types" commands when used with programs having the .gdb_index
283 section, as well as speeding up debugging with shared libraries using
284 the .gdb_index section.
286 * Ada support for GDB/MI Variable Objects has been added.
288 * GDB can now support 'breakpoint always-inserted mode' in 'record'
293 ** New command -info-os is the MI equivalent of "info os".
295 ** Output logs ("set logging" and related) now include MI output.
299 ** "set use-deprecated-index-sections on|off"
300 "show use-deprecated-index-sections on|off"
301 Controls the use of deprecated .gdb_index sections.
303 ** "catch load" and "catch unload" can be used to stop when a shared
304 library is loaded or unloaded, respectively.
306 ** "enable count" can be used to auto-disable a breakpoint after
309 ** "info vtbl" can be used to show the virtual method tables for
310 C++ and Java objects.
312 ** "explore" and its sub commands "explore value" and "explore type"
313 can be used to reccursively explore values and types of
314 expressions. These commands are available only if GDB is
315 configured with '--with-python'.
317 ** "info auto-load" shows status of all kinds of auto-loaded files,
318 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
319 sequences of commands files, "info auto-load python-scripts"
320 shows status of auto-loading Python script files,
321 "info auto-load local-gdbinit" shows status of loading init file
322 (.gdbinit) from current directory and "info auto-load libthread-db" shows
323 status of inferior specific thread debugging shared library loading.
325 ** "info auto-load-scripts", "set auto-load-scripts on|off"
326 and "show auto-load-scripts" commands have been deprecated, use their
327 "info auto-load python-scripts", "set auto-load python-scripts on|off"
328 and "show auto-load python-scripts" counterparts instead.
330 ** "dprintf location,format,args..." creates a dynamic printf, which
331 is basically a breakpoint that does a printf and immediately
332 resumes your program's execution, so it is like a printf that you
333 can insert dynamically at runtime instead of at compiletime.
335 ** "set print symbol"
337 Controls whether GDB attempts to display the symbol, if any,
338 corresponding to addresses it prints. This defaults to "on", but
339 you can set it to "off" to restore GDB's previous behavior.
341 * Deprecated commands
343 ** For the Renesas Super-H architecture, the "regs" command has been
344 deprecated, and "info all-registers" should be used instead.
348 Renesas RL78 rl78-*-elf
349 HP OpenVMS ia64 ia64-hp-openvms*
351 * GDBserver supports evaluation of breakpoint conditions. When
352 support is advertised by GDBserver, GDB may be told to send the
353 breakpoint conditions in bytecode form to GDBserver. GDBserver
354 will only report the breakpoint trigger to GDB when its condition
360 show mips compression
361 Select the compressed ISA encoding used in functions that have no symbol
362 information available. The encoding can be set to either of:
365 and is updated automatically from ELF file flags if available.
367 set breakpoint condition-evaluation
368 show breakpoint condition-evaluation
369 Control whether breakpoint conditions are evaluated by GDB ("host") or by
370 GDBserver ("target"). Default option "auto" chooses the most efficient
372 This option can improve debugger efficiency depending on the speed of the
376 Disable auto-loading globally.
379 Show auto-loading setting of all kinds of auto-loaded files.
381 set auto-load gdb-scripts on|off
382 show auto-load gdb-scripts
383 Control auto-loading of GDB canned sequences of commands files.
385 set auto-load python-scripts on|off
386 show auto-load python-scripts
387 Control auto-loading of Python script files.
389 set auto-load local-gdbinit on|off
390 show auto-load local-gdbinit
391 Control loading of init file (.gdbinit) from current directory.
393 set auto-load libthread-db on|off
394 show auto-load libthread-db
395 Control auto-loading of inferior specific thread debugging shared library.
397 set auto-load scripts-directory <dir1>[:<dir2>...]
398 show auto-load scripts-directory
399 Set a list of directories from which to load auto-loaded scripts.
400 Automatically loaded Python scripts and GDB scripts are located in one
401 of the directories listed by this option.
402 The delimiter (':' above) may differ according to the host platform.
404 set auto-load safe-path <dir1>[:<dir2>...]
405 show auto-load safe-path
406 Set a list of directories from which it is safe to auto-load files.
407 The delimiter (':' above) may differ according to the host platform.
409 set debug auto-load on|off
411 Control display of debugging info for auto-loading the files above.
413 set dprintf-style gdb|call|agent
415 Control the way in which a dynamic printf is performed; "gdb"
416 requests a GDB printf command, while "call" causes dprintf to call a
417 function in the inferior. "agent" requests that the target agent
418 (such as GDBserver) do the printing.
420 set dprintf-function <expr>
421 show dprintf-function
422 set dprintf-channel <expr>
424 Set the function and optional first argument to the call when using
425 the "call" style of dynamic printf.
427 set disconnected-dprintf on|off
428 show disconnected-dprintf
429 Control whether agent-style dynamic printfs continue to be in effect
430 after GDB disconnects.
432 * New configure options
435 Configure default value for the 'set auto-load scripts-directory'
436 setting above. It defaults to '$debugdir:$datadir/auto-load',
437 $debugdir representing global debugging info directories (available
438 via 'show debug-file-directory') and $datadir representing GDB's data
439 directory (available via 'show data-directory').
441 --with-auto-load-safe-path
442 Configure default value for the 'set auto-load safe-path' setting
443 above. It defaults to the --with-auto-load-dir setting.
445 --without-auto-load-safe-path
446 Set 'set auto-load safe-path' to '/', effectively disabling this
451 z0/z1 conditional breakpoints extension
453 The z0/z1 breakpoint insertion packets have been extended to carry
454 a list of conditional expressions over to the remote stub depending on the
455 condition evaluation mode. The use of this extension can be controlled
456 via the "set remote conditional-breakpoints-packet" command.
460 Specify the signals which the remote stub may pass to the debugged
461 program without GDB involvement.
463 * New command line options
465 --init-command=FILE, -ix Like --command, -x but execute it
466 before loading inferior.
467 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
468 execute it before loading inferior.
470 *** Changes in GDB 7.4
472 * GDB now handles ambiguous linespecs more consistently; the existing
473 FILE:LINE support has been expanded to other types of linespecs. A
474 breakpoint will now be set on all matching locations in all
475 inferiors, and locations will be added or removed according to
478 * GDB now allows you to skip uninteresting functions and files when
479 stepping with the "skip function" and "skip file" commands.
481 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
482 and "show remote hardware-watchpoint-length-limit". These allows to
483 set or show the maximum length limit (in bytes) of a remote
484 target hardware watchpoint.
486 This allows e.g. to use "unlimited" hardware watchpoints with the
487 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
488 watchpoints are slower than real hardware watchpoints but are
489 significantly faster than gdb software watchpoints.
493 ** The register_pretty_printer function in module gdb.printing now takes
494 an optional `replace' argument. If True, the new printer replaces any
497 ** The "maint set python print-stack on|off" command has been
498 deprecated and will be deleted in GDB 7.5.
499 A new command: "set python print-stack none|full|message" has
500 replaced it. Additionally, the default for "print-stack" is
501 now "message", which just prints the error message without
504 ** A prompt substitution hook (prompt_hook) is now available to the
507 ** A new Python module, gdb.prompt has been added to the GDB Python
508 modules library. This module provides functionality for
509 escape sequences in prompts (used by set/show
510 extended-prompt). These escape sequences are replaced by their
513 ** Python commands and convenience-functions located in
514 'data-directory'/python/gdb/command and
515 'data-directory'/python/gdb/function are now automatically loaded
518 ** Blocks now provide four new attributes. global_block and
519 static_block will return the global and static blocks
520 respectively. is_static and is_global are boolean attributes
521 that indicate if the block is one of those two types.
523 ** Symbols now provide the "type" attribute, the type of the symbol.
525 ** The "gdb.breakpoint" function has been deprecated in favor of
528 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
529 of a function. This class is based on the "finish" command
530 available in the CLI.
532 ** Type objects for struct and union types now allow access to
533 the fields using standard Python dictionary (mapping) methods.
534 For example, "some_type['myfield']" now works, as does
537 ** A new event "gdb.new_objfile" has been added, triggered by loading a
540 ** A new function, "deep_items" has been added to the gdb.types
541 module in the GDB Python modules library. This function returns
542 an iterator over the fields of a struct or union type. Unlike
543 the standard Python "iteritems" method, it will recursively traverse
544 any anonymous fields.
548 ** "*stopped" events can report several new "reason"s, such as
551 ** Breakpoint changes are now notified using new async records, like
552 "=breakpoint-modified".
554 ** New command -ada-task-info.
556 * libthread-db-search-path now supports two special values: $sdir and $pdir.
557 $sdir specifies the default system locations of shared libraries.
558 $pdir specifies the directory where the libpthread used by the application
561 GDB no longer looks in $sdir and $pdir after it has searched the directories
562 mentioned in libthread-db-search-path. If you want to search those
563 directories, they must be specified in libthread-db-search-path.
564 The default value of libthread-db-search-path on GNU/Linux and Solaris
565 systems is now "$sdir:$pdir".
567 $pdir is not supported by gdbserver, it is currently ignored.
568 $sdir is supported by gdbserver.
570 * New configure option --with-iconv-bin.
571 When using the internationalization support like the one in the GNU C
572 library, GDB will invoke the "iconv" program to get a list of supported
573 character sets. If this program lives in a non-standard location, one can
574 use this option to specify where to find it.
576 * When natively debugging programs on PowerPC BookE processors running
577 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
578 watchpoints, which specify a mask in addition to an address to watch.
579 The mask specifies that some bits of an address (the bits which are
580 reset in the mask) should be ignored when matching the address accessed
581 by the inferior against the watchpoint address. See the "PowerPC Embedded"
582 section in the user manual for more details.
584 * The new option --once causes GDBserver to stop listening for connections once
585 the first connection is made. The listening port used by GDBserver will
586 become available after that.
588 * New commands "info macros" and "alias" have been added.
590 * New function parameters suffix @entry specifies value of function parameter
591 at the time the function got called. Entry values are available only since
597 "!" is now an alias of the "shell" command.
598 Note that no space is needed between "!" and SHELL COMMAND.
602 watch EXPRESSION mask MASK_VALUE
603 The watch command now supports the mask argument which allows creation
604 of masked watchpoints, if the current architecture supports this feature.
606 info auto-load-scripts [REGEXP]
607 This command was formerly named "maintenance print section-scripts".
608 It is now generally useful and is no longer a maintenance-only command.
610 info macro [-all] [--] MACRO
611 The info macro command has new options `-all' and `--'. The first for
612 printing all definitions of a macro. The second for explicitly specifying
613 the end of arguments and the beginning of the macro name in case the macro
614 name starts with a hyphen.
616 collect[/s] EXPRESSIONS
617 The tracepoint collect command now takes an optional modifier "/s"
618 that directs it to dereference pointer-to-character types and
619 collect the bytes of memory up to a zero byte. The behavior is
620 similar to what you see when you use the regular print command on a
621 string. An optional integer following the "/s" sets a bound on the
622 number of bytes that will be collected.
625 The trace start command now interprets any supplied arguments as a
626 note to be recorded with the trace run, with an effect similar to
627 setting the variable trace-notes.
630 The trace stop command now interprets any arguments as a note to be
631 mentioned along with the tstatus report that the trace was stopped
632 with a command. The effect is similar to setting the variable
635 * Tracepoints can now be enabled and disabled at any time after a trace
636 experiment has been started using the standard "enable" and "disable"
637 commands. It is now possible to start a trace experiment with no enabled
638 tracepoints; GDB will display a warning, but will allow the experiment to
639 begin, assuming that tracepoints will be enabled as needed while the trace
642 * Fast tracepoints on 32-bit x86-architectures can now be placed at
643 locations with 4-byte instructions, when they were previously
644 limited to locations with instructions of 5 bytes or longer.
648 set debug dwarf2-read
649 show debug dwarf2-read
650 Turns on or off display of debugging messages related to reading
651 DWARF debug info. The default is off.
653 set debug symtab-create
654 show debug symtab-create
655 Turns on or off display of debugging messages related to symbol table
656 creation. The default is off.
660 Set the GDB prompt, and allow escape sequences to be inserted to
661 display miscellaneous information (see 'help set extended-prompt'
662 for the list of sequences). This prompt (and any information
663 accessed through the escape sequences) is updated every time the
666 set print entry-values (both|compact|default|if-needed|no|only|preferred)
667 show print entry-values
668 Set printing of frame argument values at function entry. In some cases
669 GDB can determine the value of function argument which was passed by the
670 function caller, even if the value was modified inside the called function.
672 set debug entry-values
673 show debug entry-values
674 Control display of debugging info for determining frame argument values at
675 function entry and virtual tail call frames.
677 set basenames-may-differ
678 show basenames-may-differ
679 Set whether a source file may have multiple base names.
680 (A "base name" is the name of a file with the directory part removed.
681 Example: The base name of "/home/user/hello.c" is "hello.c".)
682 If set, GDB will canonicalize file names (e.g., expand symlinks)
683 before comparing them. Canonicalization is an expensive operation,
684 but it allows the same file be known by more than one base name.
685 If not set (the default), all source files are assumed to have just
686 one base name, and gdb will do file name comparisons more efficiently.
692 Set a user name and notes for the current and any future trace runs.
693 This is useful for long-running and/or disconnected traces, to
694 inform others (or yourself) as to who is running the trace, supply
695 contact information, or otherwise explain what is going on.
698 show trace-stop-notes
699 Set a note attached to the trace run, that is displayed when the
700 trace has been stopped by a tstop command. This is useful for
701 instance as an explanation, if you are stopping a trace run that was
702 started by someone else.
708 Dynamically enable a tracepoint in a started trace experiment.
712 Dynamically disable a tracepoint in a started trace experiment.
716 Set the user and notes of the trace run.
720 Query the current status of a tracepoint.
724 Query the minimum length of instruction at which a fast tracepoint may
727 * Dcache size (number of lines) and line-size are now runtime-configurable
728 via "set dcache line" and "set dcache line-size" commands.
732 Texas Instruments TMS320C6x tic6x-*-*
736 Renesas RL78 rl78-*-elf
738 *** Changes in GDB 7.3.1
740 * The build failure for NetBSD and OpenBSD targets have now been fixed.
742 *** Changes in GDB 7.3
744 * GDB has a new command: "thread find [REGEXP]".
745 It finds the thread id whose name, target id, or thread extra info
746 matches the given regular expression.
748 * The "catch syscall" command now works on mips*-linux* targets.
750 * The -data-disassemble MI command now supports modes 2 and 3 for
751 dumping the instruction opcodes.
753 * New command line options
755 -data-directory DIR Specify DIR as the "data-directory".
756 This is mostly for testing purposes.
758 * The "maint set python auto-load on|off" command has been renamed to
759 "set auto-load-scripts on|off".
761 * GDB has a new command: "set directories".
762 It is like the "dir" command except that it replaces the
763 source path list instead of augmenting it.
765 * GDB now understands thread names.
767 On GNU/Linux, "info threads" will display the thread name as set by
768 prctl or pthread_setname_np.
770 There is also a new command, "thread name", which can be used to
771 assign a name internally for GDB to display.
774 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
775 has been integrated into GDB.
779 ** The function gdb.Write now accepts an optional keyword 'stream'.
780 This keyword, when provided, will direct the output to either
781 stdout, stderr, or GDB's logging output.
783 ** Parameters can now be be sub-classed in Python, and in particular
784 you may implement the get_set_doc and get_show_doc functions.
785 This improves how Parameter set/show documentation is processed
786 and allows for more dynamic content.
788 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
789 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
790 have an is_valid method.
792 ** Breakpoints can now be sub-classed in Python, and in particular
793 you may implement a 'stop' function that is executed each time
794 the inferior reaches that breakpoint.
796 ** New function gdb.lookup_global_symbol looks up a global symbol.
798 ** GDB values in Python are now callable if the value represents a
799 function. For example, if 'some_value' represents a function that
800 takes two integer parameters and returns a value, you can call
801 that function like so:
803 result = some_value (10,20)
805 ** Module gdb.types has been added.
806 It contains a collection of utilities for working with gdb.Types objects:
807 get_basic_type, has_field, make_enum_dict.
809 ** Module gdb.printing has been added.
810 It contains utilities for writing and registering pretty-printers.
811 New classes: PrettyPrinter, SubPrettyPrinter,
812 RegexpCollectionPrettyPrinter.
813 New function: register_pretty_printer.
815 ** New commands "info pretty-printers", "enable pretty-printer" and
816 "disable pretty-printer" have been added.
818 ** gdb.parameter("directories") is now available.
820 ** New function gdb.newest_frame returns the newest frame in the
823 ** The gdb.InferiorThread class has a new "name" attribute. This
824 holds the thread's name.
826 ** Python Support for Inferior events.
827 Python scripts can add observers to be notified of events
828 occurring in the process being debugged.
829 The following events are currently supported:
830 - gdb.events.cont Continue event.
831 - gdb.events.exited Inferior exited event.
832 - gdb.events.stop Signal received, and Breakpoint hit events.
836 ** GDB now puts template parameters in scope when debugging in an
837 instantiation. For example, if you have:
839 template<int X> int func (void) { return X; }
841 then if you step into func<5>, "print X" will show "5". This
842 feature requires proper debuginfo support from the compiler; it
843 was added to GCC 4.5.
845 ** The motion commands "next", "finish", "until", and "advance" now
846 work better when exceptions are thrown. In particular, GDB will
847 no longer lose control of the inferior; instead, the GDB will
848 stop the inferior at the point at which the exception is caught.
849 This functionality requires a change in the exception handling
850 code that was introduced in GCC 4.5.
852 * GDB now follows GCC's rules on accessing volatile objects when
853 reading or writing target state during expression evaluation.
854 One notable difference to prior behavior is that "print x = 0"
855 no longer generates a read of x; the value of the assignment is
856 now always taken directly from the value being assigned.
858 * GDB now has some support for using labels in the program's source in
859 linespecs. For instance, you can use "advance label" to continue
860 execution to a label.
862 * GDB now has support for reading and writing a new .gdb_index
863 section. This section holds a fast index of DWARF debugging
864 information and can be used to greatly speed up GDB startup and
865 operation. See the documentation for `save gdb-index' for details.
867 * The "watch" command now accepts an optional "-location" argument.
868 When used, this causes GDB to watch the memory referred to by the
869 expression. Such a watchpoint is never deleted due to it going out
872 * GDB now supports thread debugging of core dumps on GNU/Linux.
874 GDB now activates thread debugging using the libthread_db library
875 when debugging GNU/Linux core dumps, similarly to when debugging
876 live processes. As a result, when debugging a core dump file, GDB
877 is now able to display pthread_t ids of threads. For example, "info
878 threads" shows the same output as when debugging the process when it
879 was live. In earlier releases, you'd see something like this:
882 * 1 LWP 6780 main () at main.c:10
884 While now you see this:
887 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
889 It is also now possible to inspect TLS variables when debugging core
892 When debugging a core dump generated on a machine other than the one
893 used to run GDB, you may need to point GDB at the correct
894 libthread_db library with the "set libthread-db-search-path"
895 command. See the user manual for more details on this command.
897 * When natively debugging programs on PowerPC BookE processors running
898 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
899 which stop execution of the inferior whenever it executes an instruction
900 at any address within the specified range. See the "PowerPC Embedded"
901 section in the user manual for more details.
903 * New features in the GDB remote stub, GDBserver
905 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
906 and i686 LynxOS (version 5.x).
908 ** GDBserver is now supported on Blackfin Linux.
910 * New native configurations
912 ia64 HP-UX ia64-*-hpux*
916 Analog Devices, Inc. Blackfin Processor bfin-*
918 * Ada task switching is now supported on sparc-elf targets when
919 debugging a program using the Ravenscar Profile. For more information,
920 see the "Tasking Support when using the Ravenscar Profile" section
921 in the GDB user manual.
923 * Guile support was removed.
925 * New features in the GNU simulator
927 ** The --map-info flag lists all known core mappings.
929 ** CFI flashes may be simulated via the "cfi" device.
931 *** Changes in GDB 7.2
933 * Shared library support for remote targets by default
935 When GDB is configured for a generic, non-OS specific target, like
936 for example, --target=arm-eabi or one of the many *-*-elf targets,
937 GDB now queries remote stubs for loaded shared libraries using the
938 `qXfer:libraries:read' packet. Previously, shared library support
939 was always disabled for such configurations.
943 ** Argument Dependent Lookup (ADL)
945 In C++ ADL lookup directs function search to the namespaces of its
946 arguments even if the namespace has not been imported.
956 Here the compiler will search for `foo' in the namespace of 'b'
957 and find A::foo. GDB now supports this. This construct is commonly
958 used in the Standard Template Library for operators.
960 ** Improved User Defined Operator Support
962 In addition to member operators, GDB now supports lookup of operators
963 defined in a namespace and imported with a `using' directive, operators
964 defined in the global scope, operators imported implicitly from an
965 anonymous namespace, and the ADL operators mentioned in the previous
967 GDB now also supports proper overload resolution for all the previously
968 mentioned flavors of operators.
970 ** static const class members
972 Printing of static const class members that are initialized in the
973 class definition has been fixed.
975 * Windows Thread Information Block access.
977 On Windows targets, GDB now supports displaying the Windows Thread
978 Information Block (TIB) structure. This structure is visible either
979 by using the new command `info w32 thread-information-block' or, by
980 dereferencing the new convenience variable named `$_tlb', a
981 thread-specific pointer to the TIB. This feature is also supported
982 when remote debugging using GDBserver.
986 Static tracepoints are calls in the user program into a tracing
987 library. One such library is a port of the LTTng kernel tracer to
988 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
989 When debugging with GDBserver, GDB now supports combining the GDB
990 tracepoint machinery with such libraries. For example: the user can
991 use GDB to probe a static tracepoint marker (a call from the user
992 program into the tracing library) with the new "strace" command (see
993 "New commands" below). This creates a "static tracepoint" in the
994 breakpoint list, that can be manipulated with the same feature set
995 as fast and regular tracepoints. E.g., collect registers, local and
996 global variables, collect trace state variables, and define
997 tracepoint conditions. In addition, the user can collect extra
998 static tracepoint marker specific data, by collecting the new
999 $_sdata internal variable. When analyzing the trace buffer, you can
1000 inspect $_sdata like any other variable available to GDB. For more
1001 information, see the "Tracepoints" chapter in GDB user manual. New
1002 remote packets have been defined to support static tracepoints, see
1003 the "New remote packets" section below.
1005 * Better reconstruction of tracepoints after disconnected tracing
1007 GDB will attempt to download the original source form of tracepoint
1008 definitions when starting a trace run, and then will upload these
1009 upon reconnection to the target, resulting in a more accurate
1010 reconstruction of the tracepoints that are in use on the target.
1014 You can now exercise direct control over the ways that GDB can
1015 affect your program. For instance, you can disallow the setting of
1016 breakpoints, so that the program can run continuously (assuming
1017 non-stop mode). In addition, the "observer" variable is available
1018 to switch all of the different controls; in observer mode, GDB
1019 cannot affect the target's behavior at all, which is useful for
1020 tasks like diagnosing live systems in the field.
1022 * The new convenience variable $_thread holds the number of the
1025 * New remote packets
1029 Return the address of the Windows Thread Information Block of a given thread.
1033 In response to several of the tracepoint packets, the target may now
1034 also respond with a number of intermediate `qRelocInsn' request
1035 packets before the final result packet, to have GDB handle
1036 relocating an instruction to execute at a different address. This
1037 is particularly useful for stubs that support fast tracepoints. GDB
1038 reports support for this feature in the qSupported packet.
1042 List static tracepoint markers in the target program.
1046 List static tracepoint markers at a given address in the target
1049 qXfer:statictrace:read
1051 Read the static trace data collected (by a `collect $_sdata'
1052 tracepoint action). The remote stub reports support for this packet
1053 to gdb's qSupported query.
1057 Send the current settings of GDB's permission flags.
1061 Send part of the source (textual) form of a tracepoint definition,
1062 which includes location, conditional, and action list.
1064 * The source command now accepts a -s option to force searching for the
1065 script in the source search path even if the script name specifies
1068 * New features in the GDB remote stub, GDBserver
1070 - GDBserver now support tracepoints (including fast tracepoints, and
1071 static tracepoints). The feature is currently supported by the
1072 i386-linux and amd64-linux builds. See the "Tracepoints support
1073 in gdbserver" section in the manual for more information.
1075 GDBserver JIT compiles the tracepoint's conditional agent
1076 expression bytecode into native code whenever possible for low
1077 overhead dynamic tracepoints conditionals. For such tracepoints,
1078 an expression that examines program state is evaluated when the
1079 tracepoint is reached, in order to determine whether to capture
1080 trace data. If the condition is simple and false, processing the
1081 tracepoint finishes very quickly and no data is gathered.
1083 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1084 for static tracepoints support.
1086 - GDBserver now supports x86_64 Windows 64-bit debugging.
1088 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1089 it understands register description.
1091 * The --batch flag now disables pagination and queries.
1093 * X86 general purpose registers
1095 GDB now supports reading/writing byte, word and double-word x86
1096 general purpose registers directly. This means you can use, say,
1097 $ah or $ax to refer, respectively, to the byte register AH and
1098 16-bit word register AX that are actually portions of the 32-bit
1099 register EAX or 64-bit register RAX.
1101 * The `commands' command now accepts a range of breakpoints to modify.
1102 A plain `commands' following a command that creates multiple
1103 breakpoints affects all the breakpoints set by that command. This
1104 applies to breakpoints set by `rbreak', and also applies when a
1105 single `break' command creates multiple breakpoints (e.g.,
1106 breakpoints on overloaded c++ functions).
1108 * The `rbreak' command now accepts a filename specification as part of
1109 its argument, limiting the functions selected by the regex to those
1110 in the specified file.
1112 * Support for remote debugging Windows and SymbianOS shared libraries
1113 from Unix hosts has been improved. Non Windows GDB builds now can
1114 understand target reported file names that follow MS-DOS based file
1115 system semantics, such as file names that include drive letters and
1116 use the backslash character as directory separator. This makes it
1117 possible to transparently use the "set sysroot" and "set
1118 solib-search-path" on Unix hosts to point as host copies of the
1119 target's shared libraries. See the new command "set
1120 target-file-system-kind" described below, and the "Commands to
1121 specify files" section in the user manual for more information.
1125 eval template, expressions...
1126 Convert the values of one or more expressions under the control
1127 of the string template to a command line, and call it.
1129 set target-file-system-kind unix|dos-based|auto
1130 show target-file-system-kind
1131 Set or show the assumed file system kind for target reported file
1134 save breakpoints <filename>
1135 Save all current breakpoint definitions to a file suitable for use
1136 in a later debugging session. To read the saved breakpoint
1137 definitions, use the `source' command.
1139 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1142 info static-tracepoint-markers
1143 Display information about static tracepoint markers in the target.
1145 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1146 Define a static tracepoint by probing a marker at the given
1147 function, line, address, or marker ID.
1151 Enable and disable observer mode.
1153 set may-write-registers on|off
1154 set may-write-memory on|off
1155 set may-insert-breakpoints on|off
1156 set may-insert-tracepoints on|off
1157 set may-insert-fast-tracepoints on|off
1158 set may-interrupt on|off
1159 Set individual permissions for GDB effects on the target. Note that
1160 some of these settings can have undesirable or surprising
1161 consequences, particularly when changed in the middle of a session.
1162 For instance, disabling the writing of memory can prevent
1163 breakpoints from being inserted, cause single-stepping to fail, or
1164 even crash your program, if you disable after breakpoints have been
1165 inserted. However, GDB should not crash.
1167 set record memory-query on|off
1168 show record memory-query
1169 Control whether to stop the inferior if memory changes caused
1170 by an instruction cannot be recorded.
1175 The disassemble command now supports "start,+length" form of two arguments.
1179 ** GDB now provides a new directory location, called the python directory,
1180 where Python scripts written for GDB can be installed. The location
1181 of that directory is <data-directory>/python, where <data-directory>
1182 is the GDB data directory. For more details, see section `Scripting
1183 GDB using Python' in the manual.
1185 ** The GDB Python API now has access to breakpoints, symbols, symbol
1186 tables, program spaces, inferiors, threads and frame's code blocks.
1187 Additionally, GDB Parameters can now be created from the API, and
1188 manipulated via set/show in the CLI.
1190 ** New functions gdb.target_charset, gdb.target_wide_charset,
1191 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1193 ** New exception gdb.GdbError.
1195 ** Pretty-printers are now also looked up in the current program space.
1197 ** Pretty-printers can now be individually enabled and disabled.
1199 ** GDB now looks for names of Python scripts to auto-load in a
1200 special section named `.debug_gdb_scripts', in addition to looking
1201 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1203 * Tracepoint actions were unified with breakpoint commands. In particular,
1204 there are no longer differences in "info break" output for breakpoints and
1205 tracepoints and the "commands" command can be used for both tracepoints and
1206 regular breakpoints.
1210 ARM Symbian arm*-*-symbianelf*
1212 * D language support.
1213 GDB now supports debugging programs written in the D programming
1216 * GDB now supports the extended ptrace interface for PowerPC which is
1217 available since Linux kernel version 2.6.34. This automatically enables
1218 any hardware breakpoints and additional hardware watchpoints available in
1219 the processor. The old ptrace interface exposes just one hardware
1220 watchpoint and no hardware breakpoints.
1222 * GDB is now able to use the Data Value Compare (DVC) register available on
1223 embedded PowerPC processors to implement in hardware simple watchpoint
1224 conditions of the form:
1226 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1228 This works in native GDB running on Linux kernels with the extended ptrace
1229 interface mentioned above.
1231 *** Changes in GDB 7.1
1235 ** Namespace Support
1237 GDB now supports importing of namespaces in C++. This enables the
1238 user to inspect variables from imported namespaces. Support for
1239 namepace aliasing has also been added. So, if a namespace is
1240 aliased in the current scope (e.g. namepace C=A; ) the user can
1241 print variables using the alias (e.g. (gdb) print C::x).
1245 All known bugs relating to the printing of virtual base class were
1246 fixed. It is now possible to call overloaded static methods using a
1251 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1252 and reinterpret_cast<> are now handled by the C++ expression parser.
1256 Xilinx MicroBlaze microblaze-*-*
1261 Xilinx MicroBlaze microblaze
1264 * Multi-program debugging.
1266 GDB now has support for multi-program (a.k.a. multi-executable or
1267 multi-exec) debugging. This allows for debugging multiple inferiors
1268 simultaneously each running a different program under the same GDB
1269 session. See "Debugging Multiple Inferiors and Programs" in the
1270 manual for more information. This implied some user visible changes
1271 in the multi-inferior support. For example, "info inferiors" now
1272 lists inferiors that are not running yet or that have exited
1273 already. See also "New commands" and "New options" below.
1275 * New tracing features
1277 GDB's tracepoint facility now includes several new features:
1279 ** Trace state variables
1281 GDB tracepoints now include support for trace state variables, which
1282 are variables managed by the target agent during a tracing
1283 experiment. They are useful for tracepoints that trigger each
1284 other, so for instance one tracepoint can count hits in a variable,
1285 and then a second tracepoint has a condition that is true when the
1286 count reaches a particular value. Trace state variables share the
1287 $-syntax of GDB convenience variables, and can appear in both
1288 tracepoint actions and condition expressions. Use the "tvariable"
1289 command to create, and "info tvariables" to view; see "Trace State
1290 Variables" in the manual for more detail.
1294 GDB now includes an option for defining fast tracepoints, which
1295 targets may implement more efficiently, such as by installing a jump
1296 into the target agent rather than a trap instruction. The resulting
1297 speedup can be by two orders of magnitude or more, although the
1298 tradeoff is that some program locations on some target architectures
1299 might not allow fast tracepoint installation, for instance if the
1300 instruction to be replaced is shorter than the jump. To request a
1301 fast tracepoint, use the "ftrace" command, with syntax identical to
1302 the regular trace command.
1304 ** Disconnected tracing
1306 It is now possible to detach GDB from the target while it is running
1307 a trace experiment, then reconnect later to see how the experiment
1308 is going. In addition, a new variable disconnected-tracing lets you
1309 tell the target agent whether to continue running a trace if the
1310 connection is lost unexpectedly.
1314 GDB now has the ability to save the trace buffer into a file, and
1315 then use that file as a target, similarly to you can do with
1316 corefiles. You can select trace frames, print data that was
1317 collected in them, and use tstatus to display the state of the
1318 tracing run at the moment that it was saved. To create a trace
1319 file, use "tsave <filename>", and to use it, do "target tfile
1322 ** Circular trace buffer
1324 You can ask the target agent to handle the trace buffer as a
1325 circular buffer, discarding the oldest trace frames to make room for
1326 newer ones, by setting circular-trace-buffer to on. This feature may
1327 not be available for all target agents.
1332 The disassemble command, when invoked with two arguments, now requires
1333 the arguments to be comma-separated.
1336 The info variables command now displays variable definitions. Files
1337 which only declare a variable are not shown.
1340 The source command is now capable of sourcing Python scripts.
1341 This feature is dependent on the debugger being build with Python
1344 Related to this enhancement is also the introduction of a new command
1345 "set script-extension" (see below).
1347 * New commands (for set/show, see "New options" below)
1349 record save [<FILENAME>]
1350 Save a file (in core file format) containing the process record
1351 execution log for replay debugging at a later time.
1353 record restore <FILENAME>
1354 Restore the process record execution log that was saved at an
1355 earlier time, for replay debugging.
1357 add-inferior [-copies <N>] [-exec <FILENAME>]
1360 clone-inferior [-copies <N>] [ID]
1361 Make a new inferior ready to execute the same program another
1362 inferior has loaded.
1367 maint info program-spaces
1368 List the program spaces loaded into GDB.
1370 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1371 show remote interrupt-sequence
1372 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1373 as the sequence to the remote target in order to interrupt the execution.
1374 Ctrl-C is a default. Some system prefers BREAK which is high level of
1375 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1376 Magic SysRq g. It is BREAK signal and character 'g'.
1378 set remote interrupt-on-connect [on | off]
1379 show remote interrupt-on-connect
1380 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1381 remote target when gdb connects to it. This is needed when you debug
1384 set remotebreak [on | off]
1386 Deprecated. Use "set/show remote interrupt-sequence" instead.
1388 tvariable $NAME [ = EXP ]
1389 Create or modify a trace state variable.
1392 List trace state variables and their values.
1394 delete tvariable $NAME ...
1395 Delete one or more trace state variables.
1398 Evaluate the given expressions without collecting anything into the
1399 trace buffer. (Valid in tracepoint actions only.)
1401 ftrace FN / FILE:LINE / *ADDR
1402 Define a fast tracepoint at the given function, line, or address.
1404 * New expression syntax
1406 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1407 GDB now parses 0b101010 identically with 42.
1411 set follow-exec-mode new|same
1412 show follow-exec-mode
1413 Control whether GDB reuses the same inferior across an exec call or
1414 creates a new one. This is useful to be able to restart the old
1415 executable after the inferior having done an exec call.
1417 set default-collect EXPR, ...
1418 show default-collect
1419 Define a list of expressions to be collected at each tracepoint.
1420 This is a useful way to ensure essential items are not overlooked,
1421 such as registers or a critical global variable.
1423 set disconnected-tracing
1424 show disconnected-tracing
1425 If set to 1, the target is instructed to continue tracing if it
1426 loses its connection to GDB. If 0, the target is to stop tracing
1429 set circular-trace-buffer
1430 show circular-trace-buffer
1431 If set to on, the target is instructed to use a circular trace buffer
1432 and discard the oldest trace frames instead of stopping the trace due
1433 to a full trace buffer. If set to off, the trace stops when the buffer
1434 fills up. Some targets may not support this.
1436 set script-extension off|soft|strict
1437 show script-extension
1438 If set to "off", the debugger does not perform any script language
1439 recognition, and all sourced files are assumed to be GDB scripts.
1440 If set to "soft" (the default), files are sourced according to
1441 filename extension, falling back to GDB scripts if the first
1443 If set to "strict", files are sourced according to filename extension.
1445 set ada trust-PAD-over-XVS on|off
1446 show ada trust-PAD-over-XVS
1447 If off, activate a workaround against a bug in the debugging information
1448 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1449 the GCC sources for more information about the GNAT encoding and
1450 PAD types in particular). It is always safe to set this option to
1451 off, but this introduces a slight performance penalty. The default
1454 * Python API Improvements
1456 ** GDB provides the new class gdb.LazyString. This is useful in
1457 some pretty-printing cases. The new method gdb.Value.lazy_string
1458 provides a simple way to create objects of this type.
1460 ** The fields returned by gdb.Type.fields now have an
1461 `is_base_class' attribute.
1463 ** The new method gdb.Type.range returns the range of an array type.
1465 ** The new method gdb.parse_and_eval can be used to parse and
1466 evaluate an expression.
1468 * New remote packets
1471 Define a trace state variable.
1474 Get the current value of a trace state variable.
1477 Set desired tracing behavior upon disconnection.
1480 Set the trace buffer to be linear or circular.
1483 Get data about the tracepoints currently in use.
1487 Process record now works correctly with hardware watchpoints.
1489 Multiple bug fixes have been made to the mips-irix port, making it
1490 much more reliable. In particular:
1491 - Debugging threaded applications is now possible again. Previously,
1492 GDB would hang while starting the program, or while waiting for
1493 the program to stop at a breakpoint.
1494 - Attaching to a running process no longer hangs.
1495 - An error occurring while loading a core file has been fixed.
1496 - Changing the value of the PC register now works again. This fixes
1497 problems observed when using the "jump" command, or when calling
1498 a function from GDB, or even when assigning a new value to $pc.
1499 - With the "finish" and "return" commands, the return value for functions
1500 returning a small array is now correctly printed.
1501 - It is now possible to break on shared library code which gets executed
1502 during a shared library init phase (code executed while executing
1503 their .init section). Previously, the breakpoint would have no effect.
1504 - GDB is now able to backtrace through the signal handler for
1505 non-threaded programs.
1507 PIE (Position Independent Executable) programs debugging is now supported.
1508 This includes debugging execution of PIC (Position Independent Code) shared
1509 libraries although for that, it should be possible to run such libraries as an
1512 *** Changes in GDB 7.0
1514 * GDB now has an interface for JIT compilation. Applications that
1515 dynamically generate code can create symbol files in memory and register
1516 them with GDB. For users, the feature should work transparently, and
1517 for JIT developers, the interface is documented in the GDB manual in the
1518 "JIT Compilation Interface" chapter.
1520 * Tracepoints may now be conditional. The syntax is as for
1521 breakpoints; either an "if" clause appended to the "trace" command,
1522 or the "condition" command is available. GDB sends the condition to
1523 the target for evaluation using the same bytecode format as is used
1524 for tracepoint actions.
1526 * The disassemble command now supports: an optional /r modifier, print the
1527 raw instructions in hex as well as in symbolic form, and an optional /m
1528 modifier to print mixed source+assembly.
1530 * Process record and replay
1532 In a architecture environment that supports ``process record and
1533 replay'', ``process record and replay'' target can record a log of
1534 the process execution, and replay it with both forward and reverse
1537 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1538 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1539 set execution-direction {forward|reverse}, for targets that support
1542 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1543 feature is available with a native GDB running on kernel version
1546 * GDB now has support for multi-byte and wide character sets on the
1547 target. Strings whose character type is wchar_t, char16_t, or
1548 char32_t are now correctly printed. GDB supports wide- and unicode-
1549 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1550 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1551 `printf'. This feature requires iconv to work properly; if your
1552 system does not have a working iconv, GDB can use GNU libiconv. See
1553 the installation instructions for more information.
1555 * GDB now supports automatic retrieval of shared library files from
1556 remote targets. To use this feature, specify a system root that begins
1557 with the `remote:' prefix, either via the `set sysroot' command or via
1558 the `--with-sysroot' configure-time option.
1560 * "info sharedlibrary" now takes an optional regex of libraries to show,
1561 and it now reports if a shared library has no debugging information.
1563 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1564 now complete on file names.
1566 * When completing in expressions, gdb will attempt to limit
1567 completions to allowable structure or union fields, where appropriate.
1568 For instance, consider:
1570 # struct example { int f1; double f2; };
1571 # struct example variable;
1574 If the user types TAB at the end of this command line, the available
1575 completions will be "f1" and "f2".
1577 * Inlined functions are now supported. They show up in backtraces, and
1578 the "step", "next", and "finish" commands handle them automatically.
1580 * GDB now supports the token-splicing (##) and stringification (#)
1581 operators when expanding macros. It also supports variable-arity
1584 * GDB now supports inspecting extra signal information, exported by
1585 the new $_siginfo convenience variable. The feature is currently
1586 implemented on linux ARM, i386 and amd64.
1588 * GDB can now display the VFP floating point registers and NEON vector
1589 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1590 can provide these registers (requires Linux 2.6.30 or later). Remote
1591 and simulator targets may also provide them.
1593 * New remote packets
1596 Search memory for a sequence of bytes.
1599 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1600 operation over reliable transport links. Use of this packet is
1601 controlled by the `set remote noack-packet' command.
1604 Kill the process with the specified process ID. Use this in preference
1605 to `k' when multiprocess protocol extensions are supported.
1608 Obtains additional operating system information
1612 Read or write additional signal information.
1614 * Removed remote protocol undocumented extension
1616 An undocumented extension to the remote protocol's `S' stop reply
1617 packet that permited the stub to pass a process id was removed.
1618 Remote servers should use the `T' stop reply packet instead.
1620 * GDB now supports multiple function calling conventions according to the
1621 DWARF-2 DW_AT_calling_convention function attribute.
1623 * The SH target utilizes the aforementioned change to distinguish between gcc
1624 and Renesas calling convention. It also adds the new CLI commands
1625 `set/show sh calling-convention'.
1627 * GDB can now read compressed debug sections, as produced by GNU gold
1628 with the --compress-debug-sections=zlib flag.
1630 * 64-bit core files are now supported on AIX.
1632 * Thread switching is now supported on Tru64.
1634 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1635 which will be allocated using malloc later in program execution.
1637 * The qXfer:libraries:read remote procotol packet now allows passing a
1638 list of section offsets.
1640 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1641 conditions handling signals delivered during attach or thread creation
1642 have also been fixed.
1644 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1645 From the user's standpoint, all unqualified instances of True and False
1646 are treated as the standard definitions, regardless of context.
1648 * GDB now parses C++ symbol and type names more flexibly. For
1651 template<typename T> class C { };
1654 GDB will now correctly handle all of:
1656 ptype C<char const *>
1657 ptype C<char const*>
1658 ptype C<const char *>
1659 ptype C<const char*>
1661 * New features in the GDB remote stub, gdbserver
1663 - The "--wrapper" command-line argument tells gdbserver to use a
1664 wrapper program to launch programs for debugging.
1666 - On PowerPC and S/390 targets, it is now possible to use a single
1667 gdbserver executable to debug both 32-bit and 64-bit programs.
1668 (This requires gdbserver itself to be built as a 64-bit executable.)
1670 - gdbserver uses the new noack protocol mode for TCP connections to
1671 reduce communications latency, if also supported and enabled in GDB.
1673 - Support for the sparc64-linux-gnu target is now included in
1676 - The amd64-linux build of gdbserver now supports debugging both
1677 32-bit and 64-bit programs.
1679 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1680 now support hardware watchpoints, and will use them automatically
1685 GDB now has support for scripting using Python. Whether this is
1686 available is determined at configure time.
1688 New GDB commands can now be written in Python.
1690 * Ada tasking support
1692 Ada tasks can now be inspected in GDB. The following commands have
1696 Print the list of Ada tasks.
1698 Print detailed information about task number N.
1700 Print the task number of the current task.
1702 Switch the context of debugging to task number N.
1704 * Support for user-defined prefixed commands. The "define" command can
1705 add new commands to existing prefixes, e.g. "target".
1707 * Multi-inferior, multi-process debugging.
1709 GDB now has generalized support for multi-inferior debugging. See
1710 "Debugging Multiple Inferiors" in the manual for more information.
1711 Although availability still depends on target support, the command
1712 set is more uniform now. The GNU/Linux specific multi-forks support
1713 has been migrated to this new framework. This implied some user
1714 visible changes; see "New commands" and also "Removed commands"
1717 * Target descriptions can now describe the target OS ABI. See the
1718 "Target Description Format" section in the user manual for more
1721 * Target descriptions can now describe "compatible" architectures
1722 to indicate that the target can execute applications for a different
1723 architecture in addition to those for the main target architecture.
1724 See the "Target Description Format" section in the user manual for
1727 * Multi-architecture debugging.
1729 GDB now includes general supports for debugging applications on
1730 hybrid systems that use more than one single processor architecture
1731 at the same time. Each such hybrid architecture still requires
1732 specific support to be added. The only hybrid architecture supported
1733 in this version of GDB is the Cell Broadband Engine.
1735 * GDB now supports integrated debugging of Cell/B.E. applications that
1736 use both the PPU and SPU architectures. To enable support for hybrid
1737 Cell/B.E. debugging, you need to configure GDB to support both the
1738 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1739 --enable-targets configure option.
1741 * Non-stop mode debugging.
1743 For some targets, GDB now supports an optional mode of operation in
1744 which you can examine stopped threads while other threads continue
1745 to execute freely. This is referred to as non-stop mode, with the
1746 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1747 section in the user manual for more information.
1749 To be able to support remote non-stop debugging, a remote stub needs
1750 to implement the non-stop mode remote protocol extensions, as
1751 described in the "Remote Non-Stop" section of the user manual. The
1752 GDB remote stub, gdbserver, has been adjusted to support these
1753 extensions on linux targets.
1755 * New commands (for set/show, see "New options" below)
1757 catch syscall [NAME(S) | NUMBER(S)]
1758 Catch system calls. Arguments, which should be names of system
1759 calls or their numbers, mean catch only those syscalls. Without
1760 arguments, every syscall will be caught. When the inferior issues
1761 any of the specified syscalls, GDB will stop and announce the system
1762 call, both when it is called and when its call returns. This
1763 feature is currently available with a native GDB running on the
1764 Linux Kernel, under the following architectures: x86, x86_64,
1765 PowerPC and PowerPC64.
1767 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1769 Search memory for a sequence of bytes.
1771 maint set python print-stack
1772 maint show python print-stack
1773 Show a stack trace when an error is encountered in a Python script.
1776 Invoke CODE by passing it to the Python interpreter.
1781 These allow macros to be defined, undefined, and listed
1785 Show operating system information about processes.
1788 List the inferiors currently under GDB's control.
1791 Switch focus to inferior number NUM.
1794 Detach from inferior number NUM.
1797 Kill inferior number NUM.
1801 set spu stop-on-load
1802 show spu stop-on-load
1803 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1805 set spu auto-flush-cache
1806 show spu auto-flush-cache
1807 Control whether to automatically flush the software-managed cache
1808 during Cell/B.E. debugging.
1810 set sh calling-convention
1811 show sh calling-convention
1812 Control the calling convention used when calling SH target functions.
1815 show debug timestamp
1816 Control display of timestamps with GDB debugging output.
1818 set disassemble-next-line
1819 show disassemble-next-line
1820 Control display of disassembled source lines or instructions when
1823 set remote noack-packet
1824 show remote noack-packet
1825 Set/show the use of remote protocol QStartNoAckMode packet. See above
1826 under "New remote packets."
1828 set remote query-attached-packet
1829 show remote query-attached-packet
1830 Control use of remote protocol `qAttached' (query-attached) packet.
1832 set remote read-siginfo-object
1833 show remote read-siginfo-object
1834 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1837 set remote write-siginfo-object
1838 show remote write-siginfo-object
1839 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1842 set remote reverse-continue
1843 show remote reverse-continue
1844 Control use of remote protocol 'bc' (reverse-continue) packet.
1846 set remote reverse-step
1847 show remote reverse-step
1848 Control use of remote protocol 'bs' (reverse-step) packet.
1850 set displaced-stepping
1851 show displaced-stepping
1852 Control displaced stepping mode. Displaced stepping is a way to
1853 single-step over breakpoints without removing them from the debuggee.
1854 Also known as "out-of-line single-stepping".
1857 show debug displaced
1858 Control display of debugging info for displaced stepping.
1860 maint set internal-error
1861 maint show internal-error
1862 Control what GDB does when an internal error is detected.
1864 maint set internal-warning
1865 maint show internal-warning
1866 Control what GDB does when an internal warning is detected.
1871 Use a wrapper program to launch programs for debugging.
1873 set multiple-symbols (all|ask|cancel)
1874 show multiple-symbols
1875 The value of this variable can be changed to adjust the debugger behavior
1876 when an expression or a breakpoint location contains an ambiguous symbol
1877 name (an overloaded function name, for instance).
1879 set breakpoint always-inserted
1880 show breakpoint always-inserted
1881 Keep breakpoints always inserted in the target, as opposed to inserting
1882 them when resuming the target, and removing them when the target stops.
1883 This option can improve debugger performance on slow remote targets.
1885 set arm fallback-mode (arm|thumb|auto)
1886 show arm fallback-mode
1887 set arm force-mode (arm|thumb|auto)
1889 These commands control how ARM GDB determines whether instructions
1890 are ARM or Thumb. The default for both settings is auto, which uses
1891 the current CPSR value for instructions without symbols; previous
1892 versions of GDB behaved as if "set arm fallback-mode arm".
1894 set disable-randomization
1895 show disable-randomization
1896 Standalone programs run with the virtual address space randomization enabled
1897 by default on some platforms. This option keeps the addresses stable across
1898 multiple debugging sessions.
1902 Control whether other threads are stopped or not when some thread hits
1907 Requests that asynchronous execution is enabled in the target, if available.
1908 In this case, it's possible to resume target in the background, and interact
1909 with GDB while the target is running. "show target-async" displays the
1910 current state of asynchronous execution of the target.
1912 set target-wide-charset
1913 show target-wide-charset
1914 The target-wide-charset is the name of the character set that GDB
1915 uses when printing characters whose type is wchar_t.
1917 set tcp auto-retry (on|off)
1919 set tcp connect-timeout
1920 show tcp connect-timeout
1921 These commands allow GDB to retry failed TCP connections to a remote stub
1922 with a specified timeout period; this is useful if the stub is launched
1923 in parallel with GDB but may not be ready to accept connections immediately.
1925 set libthread-db-search-path
1926 show libthread-db-search-path
1927 Control list of directories which GDB will search for appropriate
1930 set schedule-multiple (on|off)
1931 show schedule-multiple
1932 Allow GDB to resume all threads of all processes or only threads of
1933 the current process.
1937 Use more aggressive caching for accesses to the stack. This improves
1938 performance of remote debugging (particularly backtraces) without
1939 affecting correctness.
1941 set interactive-mode (on|off|auto)
1942 show interactive-mode
1943 Control whether GDB runs in interactive mode (on) or not (off).
1944 When in interactive mode, GDB waits for the user to answer all
1945 queries. Otherwise, GDB does not wait and assumes the default
1946 answer. When set to auto (the default), GDB determines which
1947 mode to use based on the stdin settings.
1952 For program forks, this is replaced by the new more generic `info
1953 inferiors' command. To list checkpoints, you can still use the
1954 `info checkpoints' command, which was an alias for the `info forks'
1958 Replaced by the new `inferior' command. To switch between
1959 checkpoints, you can still use the `restart' command, which was an
1960 alias for the `fork' command.
1963 This is removed, since some targets don't have a notion of
1964 processes. To switch between processes, you can still use the
1965 `inferior' command using GDB's own inferior number.
1968 For program forks, this is replaced by the new more generic `kill
1969 inferior' command. To delete a checkpoint, you can still use the
1970 `delete checkpoint' command, which was an alias for the `delete
1974 For program forks, this is replaced by the new more generic `detach
1975 inferior' command. To detach a checkpoint, you can still use the
1976 `detach checkpoint' command, which was an alias for the `detach
1979 * New native configurations
1981 x86/x86_64 Darwin i[34567]86-*-darwin*
1983 x86_64 MinGW x86_64-*-mingw*
1987 Lattice Mico32 lm32-*
1988 x86 DICOS i[34567]86-*-dicos*
1989 x86_64 DICOS x86_64-*-dicos*
1992 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1993 (mingw32ce) debugging.
1999 These commands were actually not implemented on any target.
2001 *** Changes in GDB 6.8
2003 * New native configurations
2005 NetBSD/hppa hppa*-*netbsd*
2006 Xtensa GNU/Linux xtensa*-*-linux*
2010 NetBSD/hppa hppa*-*-netbsd*
2011 Xtensa GNU/Lunux xtensa*-*-linux*
2013 * Change in command line behavior -- corefiles vs. process ids.
2015 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2016 attaching to process NUMBER fails, GDB no longer attempts to open a
2017 core file named NUMBER. Attaching to a program using the -c option
2018 is no longer supported. Instead, use the '-p' or '--pid' options.
2020 * GDB can now be built as a native debugger for debugging Windows x86
2021 (mingw32) Portable Executable (PE) programs.
2023 * Pending breakpoints no longer change their number when their address
2026 * GDB now supports breakpoints with multiple locations,
2027 including breakpoints on C++ constructors, inside C++ templates,
2028 and in inlined functions.
2030 * GDB's ability to debug optimized code has been improved. GDB more
2031 accurately identifies function bodies and lexical blocks that occupy
2032 more than one contiguous range of addresses.
2034 * Target descriptions can now describe registers for PowerPC.
2036 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2037 registers on PowerPC targets.
2039 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2040 targets even when the libthread_db library is not available.
2042 * The GDB remote stub, gdbserver, now supports the new file transfer
2043 commands (remote put, remote get, and remote delete).
2045 * The GDB remote stub, gdbserver, now supports run and attach in
2046 extended-remote mode.
2048 * hppa*64*-*-hpux11* target broken
2049 The debugger is unable to start a program and fails with the following
2050 error: "Error trying to get information about dynamic linker".
2051 The gdb-6.7 release is also affected.
2053 * GDB now supports the --enable-targets= configure option to allow
2054 building a single GDB executable that supports multiple remote
2055 target architectures.
2057 * GDB now supports debugging C and C++ programs which use the
2058 Decimal Floating Point extension. In addition, the PowerPC target
2059 now has a set of pseudo-registers to inspect decimal float values
2060 stored in two consecutive float registers.
2062 * The -break-insert MI command can optionally create pending
2065 * Improved support for debugging Ada
2066 Many improvements to the Ada language support have been made. These
2068 - Better support for Ada2005 interface types
2069 - Improved handling of arrays and slices in general
2070 - Better support for Taft-amendment types
2071 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2073 - Improved command completion in Ada
2076 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2081 set print frame-arguments (all|scalars|none)
2082 show print frame-arguments
2083 The value of this variable can be changed to control which argument
2084 values should be printed by the debugger when displaying a frame.
2089 Transfer files to and from a remote target, and delete remote files.
2096 Transfer files to and from a remote target, and delete remote files.
2098 * New remote packets
2105 Open, close, read, write, and delete files on the remote system.
2108 Attach to an existing process on the remote system, in extended-remote
2112 Run a new process on the remote system, in extended-remote mode.
2114 *** Changes in GDB 6.7
2116 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2117 bfd, libiberty and opcodes, as revealed by static analysis donated by
2118 Coverity, Inc. (http://scan.coverity.com).
2120 * When looking up multiply-defined global symbols, GDB will now prefer the
2121 symbol definition in the current shared library if it was built using the
2122 -Bsymbolic linker option.
2124 * When the Text User Interface (TUI) is not configured, GDB will now
2125 recognize the -tui command-line option and print a message that the TUI
2128 * The GDB remote stub, gdbserver, now has lower overhead for high
2129 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2131 * GDB for MIPS targets now autodetects whether a remote target provides
2132 32-bit or 64-bit register values.
2134 * Support for C++ member pointers has been improved.
2136 * GDB now understands XML target descriptions, which specify the
2137 target's overall architecture. GDB can read a description from
2138 a local file or over the remote serial protocol.
2140 * Vectors of single-byte data use a new integer type which is not
2141 automatically displayed as character or string data.
2143 * The /s format now works with the print command. It displays
2144 arrays of single-byte integers and pointers to single-byte integers
2147 * Target descriptions can now describe target-specific registers,
2148 for architectures which have implemented the support (currently
2149 only ARM, M68K, and MIPS).
2151 * GDB and the GDB remote stub, gdbserver, now support the XScale
2154 * The GDB remote stub, gdbserver, has been updated to support
2155 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2156 has been rewritten to use the standard GDB remote protocol.
2158 * GDB can now step into C++ functions which are called through thunks.
2160 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2162 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2163 layout. It also supports a TextSeg= and DataSeg= response when only
2164 segment base addresses (rather than offsets) are available.
2166 * The /i format now outputs any trailing branch delay slot instructions
2167 immediately following the last instruction within the count specified.
2169 * The GDB remote protocol "T" stop reply packet now supports a
2170 "library" response. Combined with the new "qXfer:libraries:read"
2171 packet, this response allows GDB to debug shared libraries on targets
2172 where the operating system manages the list of loaded libraries (e.g.
2173 Windows and SymbianOS).
2175 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2176 (DLLs) on Windows and Windows CE targets.
2178 * GDB now supports a faster verification that a .debug file matches its binary
2179 according to its build-id signature, if the signature is present.
2185 Enable or disable hardware flow control (RTS/CTS) on the serial port
2186 when debugging using remote targets.
2188 set mem inaccessible-by-default
2189 show mem inaccessible-by-default
2190 If the target supplies a memory map, for instance via the remote
2191 protocol's "qXfer:memory-map:read" packet, setting this variable
2192 prevents GDB from accessing memory outside the memory map. This
2193 is useful for targets with memory mapped registers or which react
2194 badly to accesses of unmapped address space.
2196 set breakpoint auto-hw
2197 show breakpoint auto-hw
2198 If the target supplies a memory map, for instance via the remote
2199 protocol's "qXfer:memory-map:read" packet, setting this variable
2200 lets GDB use hardware breakpoints automatically for memory regions
2201 where it can not use software breakpoints. This covers both the
2202 "break" command and internal breakpoints used for other commands
2203 including "next" and "finish".
2206 catch exception unhandled
2207 Stop the program execution when Ada exceptions are raised.
2210 Stop the program execution when an Ada assertion failed.
2214 Set an alternate system root for target files. This is a more
2215 general version of "set solib-absolute-prefix", which is now
2216 an alias to "set sysroot".
2219 Provide extended SPU facility status information. This set of
2220 commands is available only when debugging the Cell/B.E. SPU
2223 * New native configurations
2225 OpenBSD/sh sh*-*openbsd*
2228 unset tdesc filename
2230 Use the specified local file as an XML target description, and do
2231 not query the target for its built-in description.
2235 OpenBSD/sh sh*-*-openbsd*
2236 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2237 Toshiba Media Processor mep-elf
2239 * New remote packets
2242 Ignore the specified signals; pass them directly to the debugged program
2243 without stopping other threads or reporting them to GDB.
2245 qXfer:features:read:
2246 Read an XML target description from the target, which describes its
2251 Read or write contents of an spufs file on the target system. These
2252 packets are available only on the Cell/B.E. SPU architecture.
2254 qXfer:libraries:read:
2255 Report the loaded shared libraries. Combined with new "T" packet
2256 response, this packet allows GDB to debug shared libraries on
2257 targets where the operating system manages the list of loaded
2258 libraries (e.g. Windows and SymbianOS).
2262 Support for these obsolete configurations has been removed.
2270 i[34567]86-*-lynxos*
2271 i[34567]86-*-netware*
2272 i[34567]86-*-sco3.2v5*
2273 i[34567]86-*-sco3.2v4*
2275 i[34567]86-*-sysv4.2*
2278 i[34567]86-*-unixware2*
2279 i[34567]86-*-unixware*
2288 * Other removed features
2295 Various m68k-only ROM monitors.
2302 Various Renesas ROM monitors and debugging interfaces for SH and
2307 Support for a Macraigor serial interface to on-chip debugging.
2308 GDB does not directly support the newer parallel or USB
2313 A debug information format. The predecessor to DWARF 2 and
2314 DWARF 3, which are still supported.
2316 Support for the HP aCC compiler on HP-UX/PA-RISC
2318 SOM-encapsulated symbolic debugging information, automatic
2319 invocation of pxdb, and the aCC custom C++ ABI. This does not
2320 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2321 with aCC can still be debugged on an assembly level.
2323 MIPS ".pdr" sections
2325 A MIPS-specific format used to describe stack frame layout
2326 in debugging information.
2330 GDB could work with an older version of Guile to debug
2331 the interpreter and Scheme programs running in it.
2333 set mips stack-arg-size
2334 set mips saved-gpreg-size
2336 Use "set mips abi" to control parameter passing for MIPS.
2338 *** Changes in GDB 6.6
2343 Cell Broadband Engine SPU spu-elf
2345 * GDB can now be configured as a cross-debugger targeting native Windows
2346 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2347 running on a Windows system over TCP/IP to debug Windows programs.
2349 * The GDB remote stub, gdbserver, has been updated to support Windows and
2350 Cygwin debugging. Both single-threaded and multi-threaded programs are
2353 * The "set trust-readonly-sections" command works again. This command was
2354 broken in GDB 6.3, 6.4, and 6.5.
2356 * The "load" command now supports writing to flash memory, if the remote
2357 stub provides the required support.
2359 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2360 longer requires symbolic debug information (e.g. DWARF-2).
2365 unset substitute-path
2366 show substitute-path
2367 Manage a list of substitution rules that GDB uses to rewrite the name
2368 of the directories where the sources are located. This can be useful
2369 for instance when the sources were moved to a different location
2370 between compilation and debugging.
2374 Print each CLI command as it is executed. Each command is prefixed with
2375 a number of `+' symbols representing the nesting depth.
2376 The source command now has a `-v' option to enable the same feature.
2380 The ARM Demon monitor support (RDP protocol, "target rdp").
2382 Kernel Object Display, an embedded debugging feature which only worked with
2383 an obsolete version of Cisco IOS.
2385 The 'set download-write-size' and 'show download-write-size' commands.
2387 * New remote packets
2390 Tell a stub about GDB client features, and request remote target features.
2391 The first feature implemented is PacketSize, which allows the target to
2392 specify the size of packets it can handle - to minimize the number of
2393 packets required and improve performance when connected to a remote
2397 Fetch an OS auxilliary vector from the remote stub. This packet is a
2398 more efficient replacement for qPart:auxv:read.
2400 qXfer:memory-map:read:
2401 Fetch a memory map from the remote stub, including information about
2402 RAM, ROM, and flash memory devices.
2407 Erase and program a flash memory device.
2409 * Removed remote packets
2412 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2413 used it, and only gdbserver implemented it.
2415 *** Changes in GDB 6.5
2419 Renesas M32C/M16C m32c-elf
2421 Morpho Technologies ms1 ms1-elf
2425 init-if-undefined Initialize a convenience variable, but
2426 only if it doesn't already have a value.
2428 The following commands are presently only implemented for native GNU/Linux:
2430 checkpoint Save a snapshot of the program state.
2432 restart <n> Return the program state to a
2433 previously saved state.
2435 info checkpoints List currently saved checkpoints.
2437 delete-checkpoint <n> Delete a previously saved checkpoint.
2439 set|show detach-on-fork Tell gdb whether to detach from a newly
2440 forked process, or to keep debugging it.
2442 info forks List forks of the user program that
2443 are available to be debugged.
2445 fork <n> Switch to debugging one of several
2446 forks of the user program that are
2447 available to be debugged.
2449 delete-fork <n> Delete a fork from the list of forks
2450 that are available to be debugged (and
2451 kill the forked process).
2453 detach-fork <n> Delete a fork from the list of forks
2454 that are available to be debugged (and
2455 allow the process to continue).
2459 Morpho Technologies ms2 ms1-elf
2461 * Improved Windows host support
2463 GDB now builds as a cross debugger hosted on i686-mingw32, including
2464 native console support, and remote communications using either
2465 network sockets or serial ports.
2467 * Improved Modula-2 language support
2469 GDB can now print most types in the Modula-2 syntax. This includes:
2470 basic types, set types, record types, enumerated types, range types,
2471 pointer types and ARRAY types. Procedure var parameters are correctly
2472 printed and hexadecimal addresses and character constants are also
2473 written in the Modula-2 syntax. Best results can be obtained by using
2474 GNU Modula-2 together with the -gdwarf-2 command line option.
2478 The ARM rdi-share module.
2480 The Netware NLM debug server.
2482 *** Changes in GDB 6.4
2484 * New native configurations
2486 OpenBSD/arm arm*-*-openbsd*
2487 OpenBSD/mips64 mips64-*-openbsd*
2491 Morpho Technologies ms1 ms1-elf
2493 * New command line options
2495 --batch-silent As for --batch, but totally silent.
2496 --return-child-result The debugger will exist with the same value
2497 the child (debugged) program exited with.
2498 --eval-command COMMAND, -ex COMMAND
2499 Execute a single GDB CLI command. This may be
2500 specified multiple times and in conjunction
2501 with the --command (-x) option.
2503 * Deprecated commands removed
2505 The following commands, that were deprecated in 2000, have been
2509 set|show arm disassembly-flavor set|show arm disassembler
2510 othernames set arm disassembler
2511 set|show remotedebug set|show debug remote
2512 set|show archdebug set|show debug arch
2513 set|show eventdebug set|show debug event
2516 * New BSD user-level threads support
2518 It is now possible to debug programs using the user-level threads
2519 library on OpenBSD and FreeBSD. Currently supported (target)
2522 FreeBSD/amd64 x86_64-*-freebsd*
2523 FreeBSD/i386 i386-*-freebsd*
2524 OpenBSD/i386 i386-*-openbsd*
2526 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2527 are not yet supported.
2529 * New support for Matsushita MN10300 w/sim added
2530 (Work in progress). mn10300-elf.
2532 * REMOVED configurations and files
2534 VxWorks and the XDR protocol *-*-vxworks
2535 Motorola MCORE mcore-*-*
2536 National Semiconductor NS32000 ns32k-*-*
2538 * New "set print array-indexes" command
2540 After turning this setting "on", GDB prints the index of each element
2541 when displaying arrays. The default is "off" to preserve the previous
2544 * VAX floating point support
2546 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2548 * User-defined command support
2550 In addition to using $arg0..$arg9 for argument passing, it is now possible
2551 to use $argc to determine now many arguments have been passed. See the
2552 section on user-defined commands in the user manual for more information.
2554 *** Changes in GDB 6.3:
2556 * New command line option
2558 GDB now accepts -l followed by a number to set the timeout for remote
2561 * GDB works with GCC -feliminate-dwarf2-dups
2563 GDB now supports a more compact representation of DWARF-2 debug
2564 information using DW_FORM_ref_addr references. These are produced
2565 by GCC with the option -feliminate-dwarf2-dups and also by some
2566 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2567 to use -feliminate-dwarf2-dups.
2569 * Internationalization
2571 When supported by the host system, GDB will be built with
2572 internationalization (libintl). The task of marking up the sources is
2573 continued, we're looking forward to our first translation.
2577 Initial support for debugging programs compiled with the GNAT
2578 implementation of the Ada programming language has been integrated
2579 into GDB. In this release, support is limited to expression evaluation.
2581 * New native configurations
2583 GNU/Linux/m32r m32r-*-linux-gnu
2587 GDB's remote protocol now includes support for the 'p' packet. This
2588 packet is used to fetch individual registers from a remote inferior.
2590 * END-OF-LIFE registers[] compatibility module
2592 GDB's internal register infrastructure has been completely rewritten.
2593 The new infrastructure making possible the implementation of key new
2594 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2597 GDB 6.3 will be the last release to include the the registers[]
2598 compatibility module that allowed out-of-date configurations to
2599 continue to work. This change directly impacts the following
2609 powerpc bdm protocol
2611 Unless there is activity to revive these configurations, they will be
2612 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2614 * OBSOLETE configurations and files
2616 Configurations that have been declared obsolete in this release have
2617 been commented out. Unless there is activity to revive these
2618 configurations, the next release of GDB will have their sources
2619 permanently REMOVED.
2628 *** Changes in GDB 6.2.1:
2630 * MIPS `break main; run' gave an heuristic-fence-post warning
2632 When attempting to run even a simple program, a warning about
2633 heuristic-fence-post being hit would be reported. This problem has
2636 * MIPS IRIX 'long double' crashed GDB
2638 When examining a long double variable, GDB would get a segmentation
2639 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2640 IRIX long double values).
2644 A bug in the VAX stack code was causing problems with the "next"
2645 command. This problem has been fixed.
2647 *** Changes in GDB 6.2:
2649 * Fix for ``many threads''
2651 On GNU/Linux systems that use the NPTL threads library, a program
2652 rapidly creating and deleting threads would confuse GDB leading to the
2655 ptrace: No such process.
2656 thread_db_get_info: cannot get thread info: generic error
2658 This problem has been fixed.
2660 * "-async" and "-noasync" options removed.
2662 Support for the broken "-noasync" option has been removed (it caused
2665 * New ``start'' command.
2667 This command runs the program until the begining of the main procedure.
2669 * New BSD Kernel Data Access Library (libkvm) interface
2671 Using ``target kvm'' it is now possible to debug kernel core dumps and
2672 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2673 platforms. Currently supported (native-only) configurations are:
2675 FreeBSD/amd64 x86_64-*-freebsd*
2676 FreeBSD/i386 i?86-*-freebsd*
2677 NetBSD/i386 i?86-*-netbsd*
2678 NetBSD/m68k m68*-*-netbsd*
2679 NetBSD/sparc sparc-*-netbsd*
2680 OpenBSD/amd64 x86_64-*-openbsd*
2681 OpenBSD/i386 i?86-*-openbsd*
2682 OpenBSD/m68k m68*-openbsd*
2683 OpenBSD/sparc sparc-*-openbsd*
2685 * Signal trampoline code overhauled
2687 Many generic problems with GDB's signal handling code have been fixed.
2688 These include: backtraces through non-contiguous stacks; recognition
2689 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2690 call; backtrace through a signal trampoline; step into and out of
2691 signal handlers; and single-stepping in the signal trampoline.
2693 Please note that kernel bugs are a limiting factor here. These
2694 features have been shown to work on an s390 GNU/Linux system that
2695 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2697 * Cygwin support for DWARF 2 added.
2699 * New native configurations
2701 GNU/Linux/hppa hppa*-*-linux*
2702 OpenBSD/hppa hppa*-*-openbsd*
2703 OpenBSD/m68k m68*-*-openbsd*
2704 OpenBSD/m88k m88*-*-openbsd*
2705 OpenBSD/powerpc powerpc-*-openbsd*
2706 NetBSD/vax vax-*-netbsd*
2707 OpenBSD/vax vax-*-openbsd*
2709 * END-OF-LIFE frame compatibility module
2711 GDB's internal frame infrastructure has been completely rewritten.
2712 The new infrastructure making it possible to support key new features
2713 including DWARF 2 Call Frame Information. To aid in the task of
2714 migrating old configurations to this new infrastructure, a
2715 compatibility module, that allowed old configurations to continue to
2716 work, was also included.
2718 GDB 6.2 will be the last release to include this frame compatibility
2719 module. This change directly impacts the following configurations:
2729 Unless there is activity to revive these configurations, they will be
2730 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2732 * REMOVED configurations and files
2734 Sun 3, running SunOS 3 m68*-*-sunos3*
2735 Sun 3, running SunOS 4 m68*-*-sunos4*
2736 Sun 2, running SunOS 3 m68000-*-sunos3*
2737 Sun 2, running SunOS 4 m68000-*-sunos4*
2738 Motorola 680x0 running LynxOS m68*-*-lynxos*
2739 AT&T 3b1/Unix pc m68*-att-*
2740 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2741 decstation mips-dec-* mips-little-*
2742 riscos mips-*-riscos* mips-*-sysv*
2743 sonymips mips-sony-*
2744 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2746 *** Changes in GDB 6.1.1:
2748 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2750 The TUI (Text-mode User Interface) is now built as part of a default
2751 GDB configuration. It is enabled by either selecting the TUI with the
2752 command line option "-i=tui" or by running the separate "gdbtui"
2753 program. For more information on the TUI, see the manual "Debugging
2756 * Pending breakpoint support (also included in GDB 6.1)
2758 Support has been added to allow you to specify breakpoints in shared
2759 libraries that have not yet been loaded. If a breakpoint location
2760 cannot be found, and the "breakpoint pending" option is set to auto,
2761 GDB queries you if you wish to make the breakpoint pending on a future
2762 shared-library load. If and when GDB resolves the breakpoint symbol,
2763 the pending breakpoint is removed as one or more regular breakpoints
2766 Pending breakpoints are very useful for GCJ Java debugging.
2768 * Fixed ISO-C build problems
2770 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2771 non ISO-C code that stopped them being built using a more strict ISO-C
2772 compiler (e.g., IBM's C compiler).
2774 * Fixed build problem on IRIX 5
2776 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2777 wasn't able to compile compile on an IRIX 5 system.
2779 * Added execute permission to gdb/gdbserver/configure
2781 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2782 permission. This bug would cause configure to fail on a number of
2783 systems (Solaris, IRIX). Ref: server/519.
2785 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2787 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2788 has been updated to use constant array sizes.
2790 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2792 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2793 its generated DWARF Call Frame Info. This encoding was causing GDB to
2794 panic, that panic has been fixed. Ref: gdb/1628.
2796 * Fixed a problem when examining parameters in shared library code.
2798 When examining parameters in optimized shared library code generated
2799 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2800 not available''. GDB now correctly displays the variable's value.
2802 *** Changes in GDB 6.1:
2804 * Removed --with-mmalloc
2806 Support for the mmalloc memory manager has been removed, as it
2807 conflicted with the internal gdb byte cache.
2809 * Changes in AMD64 configurations
2811 The AMD64 target now includes the %cs and %ss registers. As a result
2812 the AMD64 remote protocol has changed; this affects the floating-point
2813 and SSE registers. If you rely on those registers for your debugging,
2814 you should upgrade gdbserver on the remote side.
2816 * Revised SPARC target
2818 The SPARC target has been completely revised, incorporating the
2819 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2820 support for LynxOS and SunOS 4 has been dropped. Calling functions
2821 from within GDB on operating systems with a non-executable stack
2822 (Solaris, OpenBSD) now works.
2826 GDB has a new C++ demangler which does a better job on the mangled
2827 names generated by current versions of g++. It also runs faster, so
2828 with this and other changes gdb should now start faster on large C++
2831 * DWARF 2 Location Expressions
2833 GDB support for location expressions has been extended to support function
2834 arguments and frame bases. Older versions of GDB could crash when they
2837 * C++ nested types and namespaces
2839 GDB's support for nested types and namespaces in C++ has been
2840 improved, especially if you use the DWARF 2 debugging format. (This
2841 is the default for recent versions of GCC on most platforms.)
2842 Specifically, if you have a class "Inner" defined within a class or
2843 namespace "Outer", then GDB realizes that the class's name is
2844 "Outer::Inner", not simply "Inner". This should greatly reduce the
2845 frequency of complaints about not finding RTTI symbols. In addition,
2846 if you are stopped at inside of a function defined within a namespace,
2847 GDB modifies its name lookup accordingly.
2849 * New native configurations
2851 NetBSD/amd64 x86_64-*-netbsd*
2852 OpenBSD/amd64 x86_64-*-openbsd*
2853 OpenBSD/alpha alpha*-*-openbsd*
2854 OpenBSD/sparc sparc-*-openbsd*
2855 OpenBSD/sparc64 sparc64-*-openbsd*
2857 * New debugging protocols
2859 M32R with SDI protocol m32r-*-elf*
2861 * "set prompt-escape-char" command deleted.
2863 The command "set prompt-escape-char" has been deleted. This command,
2864 and its very obscure effet on GDB's prompt, was never documented,
2865 tested, nor mentioned in the NEWS file.
2867 * OBSOLETE configurations and files
2869 Configurations that have been declared obsolete in this release have
2870 been commented out. Unless there is activity to revive these
2871 configurations, the next release of GDB will have their sources
2872 permanently REMOVED.
2874 Sun 3, running SunOS 3 m68*-*-sunos3*
2875 Sun 3, running SunOS 4 m68*-*-sunos4*
2876 Sun 2, running SunOS 3 m68000-*-sunos3*
2877 Sun 2, running SunOS 4 m68000-*-sunos4*
2878 Motorola 680x0 running LynxOS m68*-*-lynxos*
2879 AT&T 3b1/Unix pc m68*-att-*
2880 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2881 decstation mips-dec-* mips-little-*
2882 riscos mips-*-riscos* mips-*-sysv*
2883 sonymips mips-sony-*
2884 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2886 * REMOVED configurations and files
2888 SGI Irix-4.x mips-sgi-irix4 or iris4
2889 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2890 Z8000 simulator z8k-zilog-none or z8ksim
2891 Matsushita MN10200 w/simulator mn10200-*-*
2892 H8/500 simulator h8500-hitachi-hms or h8500hms
2893 HP/PA running BSD hppa*-*-bsd*
2894 HP/PA running OSF/1 hppa*-*-osf*
2895 HP/PA Pro target hppa*-*-pro*
2896 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2897 386BSD i[3456]86-*-bsd*
2898 Sequent family i[3456]86-sequent-sysv4*
2899 i[3456]86-sequent-sysv*
2900 i[3456]86-sequent-bsd*
2901 SPARC running LynxOS sparc-*-lynxos*
2902 SPARC running SunOS 4 sparc-*-sunos4*
2903 Tsqware Sparclet sparclet-*-*
2904 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2906 *** Changes in GDB 6.0:
2910 Support for debugging the Objective-C programming language has been
2911 integrated into GDB.
2913 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2915 DWARF 2's Call Frame Information makes available compiler generated
2916 information that more exactly describes the program's run-time stack.
2917 By using this information, GDB is able to provide more robust stack
2920 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2921 have been updated to use a new backtrace mechanism which includes
2922 DWARF 2 CFI support.
2926 GDB's remote protocol has been extended to include support for hosted
2927 file I/O (where the remote target uses GDB's file system). See GDB's
2928 remote protocol documentation for details.
2930 * All targets using the new architecture framework.
2932 All of GDB's targets have been updated to use the new internal
2933 architecture framework. The way is now open for future GDB releases
2934 to include cross-architecture native debugging support (i386 on amd64,
2937 * GNU/Linux's Thread Local Storage (TLS)
2939 GDB now includes support for for the GNU/Linux implementation of
2940 per-thread variables.
2942 * GNU/Linux's Native POSIX Thread Library (NPTL)
2944 GDB's thread code has been updated to work with either the new
2945 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2947 * Separate debug info.
2949 GDB, in conjunction with BINUTILS, now supports a mechanism for
2950 automatically loading debug information from a separate file. Instead
2951 of shipping full debug and non-debug versions of system libraries,
2952 system integrators can now instead ship just the stripped libraries
2953 and optional debug files.
2955 * DWARF 2 Location Expressions
2957 DWARF 2 Location Expressions allow the compiler to more completely
2958 describe the location of variables (even in optimized code) to the
2961 GDB now includes preliminary support for location expressions (support
2962 for DW_OP_piece is still missing).
2966 A number of long standing bugs that caused GDB to die while starting a
2967 Java application have been fixed. GDB's Java support is now
2968 considered "useable".
2970 * GNU/Linux support for fork, vfork, and exec.
2972 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2973 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2976 * GDB supports logging output to a file
2978 There are two new commands, "set logging" and "show logging", which can be
2979 used to capture GDB's output to a file.
2981 * The meaning of "detach" has changed for gdbserver
2983 The "detach" command will now resume the application, as documented. To
2984 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2987 * d10v, m68hc11 `regs' command deprecated
2989 The `info registers' command has been updated so that it displays the
2990 registers using a format identical to the old `regs' command.
2994 A new command, "maint set profile on/off", has been added. This command can
2995 be used to enable or disable profiling while running GDB, to profile a
2996 session or a set of commands. In addition there is a new configure switch,
2997 "--enable-profiling", which will cause GDB to be compiled with profiling
2998 data, for more informative profiling results.
3000 * Default MI syntax changed to "mi2".
3002 The default MI (machine interface) syntax, enabled by the command line
3003 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3004 "mi1", can be enabled by specifying the option "-i=mi1".
3006 Support for the original "mi0" syntax (included in GDB 5.0) has been
3009 Fix for gdb/192: removed extraneous space when displaying frame level.
3010 Fix for gdb/672: update changelist is now output in mi list format.
3011 Fix for gdb/702: a -var-assign that updates the value now shows up
3012 in a subsequent -var-update.
3014 * New native configurations.
3016 FreeBSD/amd64 x86_64-*-freebsd*
3018 * Multi-arched targets.
3020 HP/PA HPUX11 hppa*-*-hpux*
3021 Renesas M32R/D w/simulator m32r-*-elf*
3023 * OBSOLETE configurations and files
3025 Configurations that have been declared obsolete in this release have
3026 been commented out. Unless there is activity to revive these
3027 configurations, the next release of GDB will have their sources
3028 permanently REMOVED.
3030 Z8000 simulator z8k-zilog-none or z8ksim
3031 Matsushita MN10200 w/simulator mn10200-*-*
3032 H8/500 simulator h8500-hitachi-hms or h8500hms
3033 HP/PA running BSD hppa*-*-bsd*
3034 HP/PA running OSF/1 hppa*-*-osf*
3035 HP/PA Pro target hppa*-*-pro*
3036 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3037 Sequent family i[3456]86-sequent-sysv4*
3038 i[3456]86-sequent-sysv*
3039 i[3456]86-sequent-bsd*
3040 Tsqware Sparclet sparclet-*-*
3041 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3043 * REMOVED configurations and files
3046 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3047 IBM AIX PS/2 i[3456]86-*-aix
3048 i386 running Mach 3.0 i[3456]86-*-mach3*
3049 i386 running Mach i[3456]86-*-mach*
3050 i386 running OSF/1 i[3456]86-*osf1mk*
3051 HP/Apollo 68k Family m68*-apollo*-sysv*,
3053 m68*-hp-bsd*, m68*-hp-hpux*
3054 Argonaut Risc Chip (ARC) arc-*-*
3055 Mitsubishi D30V d30v-*-*
3056 Fujitsu FR30 fr30-*-elf*
3057 OS/9000 i[34]86-*-os9k
3058 I960 with MON960 i960-*-coff
3060 * MIPS $fp behavior changed
3062 The convenience variable $fp, for the MIPS, now consistently returns
3063 the address of the current frame's base. Previously, depending on the
3064 context, $fp could refer to either $sp or the current frame's base
3065 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3066 The GNU Source-Level Debugger''.
3068 *** Changes in GDB 5.3:
3070 * GNU/Linux shared library multi-threaded performance improved.
3072 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3073 `/proc', in preference to `ptrace' for memory reads. This may result
3074 in an improvement in the start-up time of multi-threaded, shared
3075 library applications when run under GDB. One GDB user writes: ``loads
3076 shared libs like mad''.
3078 * ``gdbserver'' now supports multi-threaded applications on some targets
3080 Support for debugging multi-threaded applications which use
3081 the GNU/Linux LinuxThreads package has been added for
3082 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3083 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3085 * GDB now supports C/C++ preprocessor macros.
3087 GDB now expands preprocessor macro invocations in C/C++ expressions,
3088 and provides various commands for showing macro definitions and how
3091 The new command `macro expand EXPRESSION' expands any macro
3092 invocations in expression, and shows the result.
3094 The new command `show macro MACRO-NAME' shows the definition of the
3095 macro named MACRO-NAME, and where it was defined.
3097 Most compilers don't include information about macros in the debugging
3098 information by default. In GCC 3.1, for example, you need to compile
3099 your program with the options `-gdwarf-2 -g3'. If the macro
3100 information is present in the executable, GDB will read it.
3102 * Multi-arched targets.
3104 DEC Alpha (partial) alpha*-*-*
3105 DEC VAX (partial) vax-*-*
3107 National Semiconductor NS32000 (partial) ns32k-*-*
3108 Motorola 68000 (partial) m68k-*-*
3109 Motorola MCORE mcore-*-*
3113 Fujitsu FRV architecture added by Red Hat frv*-*-*
3116 * New native configurations
3118 Alpha NetBSD alpha*-*-netbsd*
3119 SH NetBSD sh*-*-netbsdelf*
3120 MIPS NetBSD mips*-*-netbsd*
3121 UltraSPARC NetBSD sparc64-*-netbsd*
3123 * OBSOLETE configurations and files
3125 Configurations that have been declared obsolete in this release have
3126 been commented out. Unless there is activity to revive these
3127 configurations, the next release of GDB will have their sources
3128 permanently REMOVED.
3130 Mitsubishi D30V d30v-*-*
3131 OS/9000 i[34]86-*-os9k
3132 IBM AIX PS/2 i[3456]86-*-aix
3133 Fujitsu FR30 fr30-*-elf*
3134 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3135 Argonaut Risc Chip (ARC) arc-*-*
3136 i386 running Mach 3.0 i[3456]86-*-mach3*
3137 i386 running Mach i[3456]86-*-mach*
3138 i386 running OSF/1 i[3456]86-*osf1mk*
3139 HP/Apollo 68k Family m68*-apollo*-sysv*,
3141 m68*-hp-bsd*, m68*-hp-hpux*
3142 I960 with MON960 i960-*-coff
3144 * OBSOLETE languages
3146 CHILL, a Pascal like language used by telecommunications companies.
3148 * REMOVED configurations and files
3150 AMD 29k family via UDI a29k-amd-udi, udi29k
3151 A29K VxWorks a29k-*-vxworks
3152 AMD 29000 embedded, using EBMON a29k-none-none
3153 AMD 29000 embedded with COFF a29k-none-coff
3154 AMD 29000 embedded with a.out a29k-none-aout
3156 testsuite/gdb.hp/gdb.threads-hp/ directory
3158 * New command "set max-user-call-depth <nnn>"
3160 This command allows the user to limit the call depth of user-defined
3161 commands. The default is 1024.
3163 * Changes in FreeBSD/i386 native debugging.
3165 Support for the "generate-core-file" has been added.
3167 * New commands "dump", "append", and "restore".
3169 These commands allow data to be copied from target memory
3170 to a bfd-format or binary file (dump and append), and back
3171 from a file into memory (restore).
3173 * Improved "next/step" support on multi-processor Alpha Tru64.
3175 The previous single-step mechanism could cause unpredictable problems,
3176 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3177 of a software single-step mechanism prevents this.
3179 *** Changes in GDB 5.2.1:
3187 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3188 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3189 Fix, by Joel Brobecker imported from mainline.
3191 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3192 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3193 Fix, by Fred Fish, imported from mainline.
3195 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3196 Surprisingly enough, it works now.
3197 By Michal Ludvig, imported from mainline.
3199 i386 hardware watchpoint support:
3200 avoid misses on second run for some targets.
3201 By Pierre Muller, imported from mainline.
3203 *** Changes in GDB 5.2:
3205 * New command "set trust-readonly-sections on[off]".
3207 This command is a hint that tells gdb that read-only sections
3208 really are read-only (ie. that their contents will not change).
3209 In this mode, gdb will go to the object file rather than the
3210 target to read memory from read-only sections (such as ".text").
3211 This can be a significant performance improvement on some
3212 (notably embedded) targets.
3214 * New command "generate-core-file" (or "gcore").
3216 This new gdb command allows the user to drop a core file of the child
3217 process state at any time. So far it's been implemented only for
3218 GNU/Linux and Solaris, but should be relatively easily ported to other
3219 hosts. Argument is core file name (defaults to core.<pid>).
3221 * New command line option
3223 GDB now accepts --pid or -p followed by a process id.
3225 * Change in command line behavior -- corefiles vs. process ids.
3227 There is a subtle behavior in the way in which GDB handles
3228 command line arguments. The first non-flag argument is always
3229 a program to debug, but the second non-flag argument may either
3230 be a corefile or a process id. Previously, GDB would attempt to
3231 open the second argument as a corefile, and if that failed, would
3232 issue a superfluous error message and then attempt to attach it as
3233 a process. Now, if the second argument begins with a non-digit,
3234 it will be treated as a corefile. If it begins with a digit,
3235 GDB will attempt to attach it as a process, and if no such process
3236 is found, will then attempt to open it as a corefile.
3238 * Changes in ARM configurations.
3240 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3241 configuration is fully multi-arch.
3243 * New native configurations
3245 ARM NetBSD arm*-*-netbsd*
3246 x86 OpenBSD i[3456]86-*-openbsd*
3247 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3248 Sparc64 running FreeBSD sparc64-*-freebsd*
3252 Sanyo XStormy16 xstormy16-elf
3254 * OBSOLETE configurations and files
3256 Configurations that have been declared obsolete in this release have
3257 been commented out. Unless there is activity to revive these
3258 configurations, the next release of GDB will have their sources
3259 permanently REMOVED.
3261 AMD 29k family via UDI a29k-amd-udi, udi29k
3262 A29K VxWorks a29k-*-vxworks
3263 AMD 29000 embedded, using EBMON a29k-none-none
3264 AMD 29000 embedded with COFF a29k-none-coff
3265 AMD 29000 embedded with a.out a29k-none-aout
3267 testsuite/gdb.hp/gdb.threads-hp/ directory
3269 * REMOVED configurations and files
3271 TI TMS320C80 tic80-*-*
3273 PowerPC Solaris powerpcle-*-solaris*
3274 PowerPC Windows NT powerpcle-*-cygwin32
3275 PowerPC Netware powerpc-*-netware*
3276 Harris/CXUX m88k m88*-harris-cxux*
3277 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3278 ns32k-utek-sysv* ns32k-utek-*
3279 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3280 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3281 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3282 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3283 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3285 * Changes to command line processing
3287 The new `--args' feature can be used to specify command-line arguments
3288 for the inferior from gdb's command line.
3290 * Changes to key bindings
3292 There is a new `operate-and-get-next' function bound to `C-o'.
3294 *** Changes in GDB 5.1.1
3296 Fix compile problem on DJGPP.
3298 Fix a problem with floating-point registers on the i386 being
3301 Fix to stop GDB crashing on .debug_str debug info.
3303 Numerous documentation fixes.
3305 Numerous testsuite fixes.
3307 *** Changes in GDB 5.1:
3309 * New native configurations
3311 Alpha FreeBSD alpha*-*-freebsd*
3312 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3313 MIPS GNU/Linux mips*-*-linux*
3314 MIPS SGI Irix 6.x mips*-sgi-irix6*
3315 ia64 AIX ia64-*-aix*
3316 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3320 Motorola 68HC11 and 68HC12 m68hc11-elf
3322 UltraSparc running GNU/Linux sparc64-*-linux*
3324 * OBSOLETE configurations and files
3326 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3327 Harris/CXUX m88k m88*-harris-cxux*
3328 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3329 ns32k-utek-sysv* ns32k-utek-*
3330 TI TMS320C80 tic80-*-*
3332 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3333 PowerPC Solaris powerpcle-*-solaris*
3334 PowerPC Windows NT powerpcle-*-cygwin32
3335 PowerPC Netware powerpc-*-netware*
3336 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3337 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3338 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3339 Apple Macintosh (MPW) host N/A
3341 stuff.c (Program to stuff files into a specially prepared space in kdb)
3342 kdb-start.c (Main loop for the standalone kernel debugger)
3344 Configurations that have been declared obsolete in this release have
3345 been commented out. Unless there is activity to revive these
3346 configurations, the next release of GDB will have their sources
3347 permanently REMOVED.
3349 * REMOVED configurations and files
3351 Altos 3068 m68*-altos-*
3352 Convex c1-*-*, c2-*-*
3354 ARM RISCix arm-*-* (as host)
3358 * GDB has been converted to ISO C.
3360 GDB's source code has been converted to ISO C. In particular, the
3361 sources are fully protoized, and rely on standard headers being
3366 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3368 * The MI enabled by default.
3370 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3371 revised and enabled by default. Packages which use GDB as a debugging
3372 engine behind a UI or another front end are encouraged to switch to
3373 using the GDB/MI interface, instead of the old annotations interface
3374 which is now deprecated.
3376 * Support for debugging Pascal programs.
3378 GDB now includes support for debugging Pascal programs. The following
3379 main features are supported:
3381 - Pascal-specific data types such as sets;
3383 - automatic recognition of Pascal sources based on file-name
3386 - Pascal-style display of data types, variables, and functions;
3388 - a Pascal expression parser.
3390 However, some important features are not yet supported.
3392 - Pascal string operations are not supported at all;
3394 - there are some problems with boolean types;
3396 - Pascal type hexadecimal constants are not supported
3397 because they conflict with the internal variables format;
3399 - support for Pascal objects and classes is not full yet;
3401 - unlike Pascal, GDB is case-sensitive for symbol names.
3403 * Changes in completion.
3405 Commands such as `shell', `run' and `set args', which pass arguments
3406 to inferior programs, now complete on file names, similar to what
3407 users expect at the shell prompt.
3409 Commands which accept locations, such as `disassemble', `print',
3410 `breakpoint', `until', etc. now complete on filenames as well as
3411 program symbols. Thus, if you type "break foob TAB", and the source
3412 files linked into the programs include `foobar.c', that file name will
3413 be one of the candidates for completion. However, file names are not
3414 considered for completion after you typed a colon that delimits a file
3415 name from a name of a function in that file, as in "break foo.c:bar".
3417 `set demangle-style' completes on available demangling styles.
3419 * New platform-independent commands:
3421 It is now possible to define a post-hook for a command as well as a
3422 hook that runs before the command. For more details, see the
3423 documentation of `hookpost' in the GDB manual.
3425 * Changes in GNU/Linux native debugging.
3427 Support for debugging multi-threaded programs has been completely
3428 revised for all platforms except m68k and sparc. You can now debug as
3429 many threads as your system allows you to have.
3431 Attach/detach is supported for multi-threaded programs.
3433 Support for SSE registers was added for x86. This doesn't work for
3434 multi-threaded programs though.
3436 * Changes in MIPS configurations.
3438 Multi-arch support is enabled for all MIPS configurations.
3440 GDB can now be built as native debugger on SGI Irix 6.x systems for
3441 debugging n32 executables. (Debugging 64-bit executables is not yet
3444 * Unified support for hardware watchpoints in all x86 configurations.
3446 Most (if not all) native x86 configurations support hardware-assisted
3447 breakpoints and watchpoints in a unified manner. This support
3448 implements debug register sharing between watchpoints, which allows to
3449 put a virtually infinite number of watchpoints on the same address,
3450 and also supports watching regions up to 16 bytes with several debug
3453 The new maintenance command `maintenance show-debug-regs' toggles
3454 debugging print-outs in functions that insert, remove, and test
3455 watchpoints and hardware breakpoints.
3457 * Changes in the DJGPP native configuration.
3459 New command ``info dos sysinfo'' displays assorted information about
3460 the CPU, OS, memory, and DPMI server.
3462 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3463 display information about segment descriptors stored in GDT, LDT, and
3466 New commands ``info dos pde'' and ``info dos pte'' display entries
3467 from Page Directory and Page Tables (for now works with CWSDPMI only).
3468 New command ``info dos address-pte'' displays the Page Table entry for
3469 a given linear address.
3471 GDB can now pass command lines longer than 126 characters to the
3472 program being debugged (requires an update to the libdbg.a library
3473 which is part of the DJGPP development kit).
3475 DWARF2 debug info is now supported.
3477 It is now possible to `step' and `next' through calls to `longjmp'.
3479 * Changes in documentation.
3481 All GDB documentation was converted to GFDL, the GNU Free
3482 Documentation License.
3484 Tracepoints-related commands are now fully documented in the GDB
3487 TUI, the Text-mode User Interface, is now documented in the manual.
3489 Tracepoints-related commands are now fully documented in the GDB
3492 The "GDB Internals" manual now has an index. It also includes
3493 documentation of `ui_out' functions, GDB coding standards, x86
3494 hardware watchpoints, and memory region attributes.
3496 * GDB's version number moved to ``version.in''
3498 The Makefile variable VERSION has been replaced by the file
3499 ``version.in''. People creating GDB distributions should update the
3500 contents of this file.
3504 GUD support is now a standard part of the EMACS distribution.
3506 *** Changes in GDB 5.0:
3508 * Improved support for debugging FP programs on x86 targets
3510 Unified and much-improved support for debugging floating-point
3511 programs on all x86 targets. In particular, ``info float'' now
3512 displays the FP registers in the same format on all x86 targets, with
3513 greater level of detail.
3515 * Improvements and bugfixes in hardware-assisted watchpoints
3517 It is now possible to watch array elements, struct members, and
3518 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3519 on x86 targets no longer erroneously trigger when the address is
3522 * Improvements in the native DJGPP version of GDB
3524 The distribution now includes all the scripts and auxiliary files
3525 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3526 machines ``out of the box''.
3528 The DJGPP version can now debug programs that use signals. It is
3529 possible to catch signals that happened in the debuggee, deliver
3530 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3531 would kill the program being debugged.) Programs that hook hardware
3532 interrupts (keyboard, timer, etc.) can also be debugged.
3534 It is now possible to debug DJGPP programs that redirect their
3535 standard handles or switch them to raw (as opposed to cooked) mode, or
3536 even close them. The command ``run < foo > bar'' works as expected,
3537 and ``info terminal'' reports useful information about the debuggee's
3538 terminal, including raw/cooked mode, redirection, etc.
3540 The DJGPP version now uses termios functions for console I/O, which
3541 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3544 DOS-style file names with drive letters are now fully supported by
3547 It is now possible to debug DJGPP programs that switch their working
3548 directory. It is also possible to rerun the debuggee any number of
3549 times without restarting GDB; thus, you can use the same setup,
3550 breakpoints, etc. for many debugging sessions.
3552 * New native configurations
3554 ARM GNU/Linux arm*-*-linux*
3555 PowerPC GNU/Linux powerpc-*-linux*
3559 Motorola MCore mcore-*-*
3560 x86 VxWorks i[3456]86-*-vxworks*
3561 PowerPC VxWorks powerpc-*-vxworks*
3562 TI TMS320C80 tic80-*-*
3564 * OBSOLETE configurations
3566 Altos 3068 m68*-altos-*
3567 Convex c1-*-*, c2-*-*
3569 ARM RISCix arm-*-* (as host)
3572 Configurations that have been declared obsolete will be commented out,
3573 but the code will be left in place. If there is no activity to revive
3574 these configurations before the next release of GDB, the sources will
3575 be permanently REMOVED.
3577 * Gould support removed
3579 Support for the Gould PowerNode and NP1 has been removed.
3581 * New features for SVR4
3583 On SVR4 native platforms (such as Solaris), if you attach to a process
3584 without first loading a symbol file, GDB will now attempt to locate and
3585 load symbols from the running process's executable file.
3587 * Many C++ enhancements
3589 C++ support has been greatly improved. Overload resolution now works properly
3590 in almost all cases. RTTI support is on the way.
3592 * Remote targets can connect to a sub-program
3594 A popen(3) style serial-device has been added. This device starts a
3595 sub-process (such as a stand-alone simulator) and then communicates
3596 with that. The sub-program to run is specified using the syntax
3597 ``|<program> <args>'' vis:
3599 (gdb) set remotedebug 1
3600 (gdb) target extended-remote |mn10300-elf-sim program-args
3602 * MIPS 64 remote protocol
3604 A long standing bug in the mips64 remote protocol where by GDB
3605 expected certain 32 bit registers (ex SR) to be transfered as 32
3606 instead of 64 bits has been fixed.
3608 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3609 added to provide backward compatibility with older versions of GDB.
3611 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3613 The command ``set remotebinarydownload'' command has been replaced by
3614 ``set remote X-packet''. Other commands in ``set remote'' family
3615 include ``set remote P-packet''.
3617 * Breakpoint commands accept ranges.
3619 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3620 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3621 ``tracepoint passcount'' also accepts a range of tracepoints.
3623 * ``apropos'' command added.
3625 The ``apropos'' command searches through command names and
3626 documentation strings, printing out matches, making it much easier to
3627 try to find a command that does what you are looking for.
3631 A new machine oriented interface (MI) has been added to GDB. This
3632 interface is designed for debug environments running GDB as a separate
3633 process. This is part of the long term libGDB project. See the
3634 "GDB/MI" chapter of the GDB manual for further information. It can be
3635 enabled by configuring with:
3637 .../configure --enable-gdbmi
3639 *** Changes in GDB-4.18:
3641 * New native configurations
3643 HP-UX 10.20 hppa*-*-hpux10.20
3644 HP-UX 11.x hppa*-*-hpux11.0*
3645 M68K GNU/Linux m68*-*-linux*
3649 Fujitsu FR30 fr30-*-elf*
3650 Intel StrongARM strongarm-*-*
3651 Mitsubishi D30V d30v-*-*
3653 * OBSOLETE configurations
3655 Gould PowerNode, NP1 np1-*-*, pn-*-*
3657 Configurations that have been declared obsolete will be commented out,
3658 but the code will be left in place. If there is no activity to revive
3659 these configurations before the next release of GDB, the sources will
3660 be permanently REMOVED.
3664 As a compatibility experiment, GDB's source files buildsym.h and
3665 buildsym.c have been converted to pure standard C, no longer
3666 containing any K&R compatibility code. We believe that all systems in
3667 use today either come with a standard C compiler, or have a GCC port
3668 available. If this is not true, please report the affected
3669 configuration to bug-gdb@gnu.org immediately. See the README file for
3670 information about getting a standard C compiler if you don't have one
3675 GDB now uses readline 2.2.
3677 * set extension-language
3679 You can now control the mapping between filename extensions and source
3680 languages by using the `set extension-language' command. For instance,
3681 you can ask GDB to treat .c files as C++ by saying
3682 set extension-language .c c++
3683 The command `info extensions' lists all of the recognized extensions
3684 and their associated languages.
3686 * Setting processor type for PowerPC and RS/6000
3688 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3689 you can use the `set processor' command to specify what variant of the
3690 PowerPC family you are debugging. The command
3694 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3695 following PowerPC and RS6000 variants:
3697 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3698 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3700 403GC IBM PowerPC 403GC
3701 505 Motorola PowerPC 505
3702 860 Motorola PowerPC 860 or 850
3703 601 Motorola PowerPC 601
3704 602 Motorola PowerPC 602
3705 603 Motorola/IBM PowerPC 603 or 603e
3706 604 Motorola PowerPC 604 or 604e
3707 750 Motorola/IBM PowerPC 750 or 750
3709 At the moment, this command just tells GDB what to name the
3710 special-purpose processor registers. Since almost all the affected
3711 registers are inaccessible to user-level programs, this command is
3712 only useful for remote debugging in its present form.
3716 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3717 more extensive support for HP-UX. Added features include shared
3718 library support, kernel threads and hardware watchpoints for 11.00,
3719 support for HP's ANSI C and C++ compilers, and a compatibility mode
3720 for xdb and dbx commands.
3724 HP's donation includes the new concept of catchpoints, which is a
3725 generalization of the old catch command. On HP-UX, it is now possible
3726 to catch exec, fork, and vfork, as well as library loading.
3728 This means that the existing catch command has changed; its first
3729 argument now specifies the type of catch to be set up. See the
3730 output of "help catch" for a list of catchpoint types.
3732 * Debugging across forks
3734 On HP-UX, you can choose which process to debug when a fork() happens
3739 HP has donated a curses-based terminal user interface (TUI). To get
3740 it, build with --enable-tui. Although this can be enabled for any
3741 configuration, at present it only works for native HP debugging.
3743 * GDB remote protocol additions
3745 A new protocol packet 'X' that writes binary data is now available.
3746 Default behavior is to try 'X', then drop back to 'M' if the stub
3747 fails to respond. The settable variable `remotebinarydownload'
3748 allows explicit control over the use of 'X'.
3750 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3751 full 64-bit address. The command
3753 set remoteaddresssize 32
3755 can be used to revert to the old behaviour. For existing remote stubs
3756 the change should not be noticed, as the additional address information
3759 In order to assist in debugging stubs, you may use the maintenance
3760 command `packet' to send any text string to the stub. For instance,
3762 maint packet heythere
3764 sends the packet "$heythere#<checksum>". Note that it is very easy to
3765 disrupt a debugging session by sending the wrong packet at the wrong
3768 The compare-sections command allows you to compare section data on the
3769 target to what is in the executable file without uploading or
3770 downloading, by comparing CRC checksums.
3772 * Tracing can collect general expressions
3774 You may now collect general expressions at tracepoints. This requires
3775 further additions to the target-side stub; see tracepoint.c and
3776 doc/agentexpr.texi for further details.
3778 * mask-address variable for Mips
3780 For Mips targets, you may control the zeroing of the upper 32 bits of
3781 a 64-bit address by entering `set mask-address on'. This is mainly
3782 of interest to users of embedded R4xxx and R5xxx processors.
3784 * Higher serial baud rates
3786 GDB's serial code now allows you to specify baud rates 57600, 115200,
3787 230400, and 460800 baud. (Note that your host system may not be able
3788 to achieve all of these rates.)
3792 The i960 configuration now includes an initial implementation of a
3793 builtin simulator, contributed by Jim Wilson.
3796 *** Changes in GDB-4.17:
3798 * New native configurations
3800 Alpha GNU/Linux alpha*-*-linux*
3801 Unixware 2.x i[3456]86-unixware2*
3802 Irix 6.x mips*-sgi-irix6*
3803 PowerPC GNU/Linux powerpc-*-linux*
3804 PowerPC Solaris powerpcle-*-solaris*
3805 Sparc GNU/Linux sparc-*-linux*
3806 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3810 Argonaut Risc Chip (ARC) arc-*-*
3811 Hitachi H8/300S h8300*-*-*
3812 Matsushita MN10200 w/simulator mn10200-*-*
3813 Matsushita MN10300 w/simulator mn10300-*-*
3814 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3815 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3816 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3817 Mitsubishi D10V w/simulator d10v-*-*
3818 Mitsubishi M32R/D w/simulator m32r-*-elf*
3819 Tsqware Sparclet sparclet-*-*
3820 NEC V850 w/simulator v850-*-*
3822 * New debugging protocols
3824 ARM with RDI protocol arm*-*-*
3825 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3826 DDB and LSI variants of PMON protocol mips*-*-*
3827 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3828 PowerPC with SDS protocol powerpc{,le}-*-eabi
3829 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3833 All configurations can now understand and use the DWARF 2 debugging
3834 format. The choice is automatic, if the symbol file contains DWARF 2
3839 GDB now includes basic Java language support. This support is
3840 only useful with Java compilers that produce native machine code.
3842 * solib-absolute-prefix and solib-search-path
3844 For SunOS and SVR4 shared libraries, you may now set the prefix for
3845 loading absolute shared library symbol files, and the search path for
3846 locating non-absolute shared library symbol files.
3848 * Live range splitting
3850 GDB can now effectively debug code for which GCC has performed live
3851 range splitting as part of its optimization. See gdb/doc/LRS for
3852 more details on the expected format of the stabs information.
3856 GDB's support for the GNU Hurd, including thread debugging, has been
3857 updated to work with current versions of the Hurd.
3861 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3862 instruction set. ARM GDB automatically detects when Thumb
3863 instructions are in use, and adjusts disassembly and backtracing
3868 GDB's MIPS target configurations now handle the MIP16 16-bit
3873 GDB now includes support for overlays; if an executable has been
3874 linked such that multiple sections are based at the same address, GDB
3875 will decide which section to use for symbolic info. You can choose to
3876 control the decision manually, using overlay commands, or implement
3877 additional target-side support and use "overlay load-target" to bring
3878 in the overlay mapping. Do "help overlay" for more detail.
3882 The command "info symbol <address>" displays information about
3883 the symbol at the specified address.
3887 The standard remote protocol now includes an extension that allows
3888 asynchronous collection and display of trace data. This requires
3889 extensive support in the target-side debugging stub. Tracing mode
3890 includes a new interaction mode in GDB and new commands: see the
3891 file tracepoint.c for more details.
3895 Configurations for embedded MIPS now include a simulator contributed
3896 by Cygnus Solutions. The simulator supports the instruction sets
3897 of most MIPS variants.
3901 Sparc configurations may now include the ERC32 simulator contributed
3902 by the European Space Agency. The simulator is not built into
3903 Sparc targets by default; configure with --enable-sim to include it.
3907 For target configurations that may include multiple variants of a
3908 basic architecture (such as MIPS and SH), you may now set the
3909 architecture explicitly. "set arch" sets, "info arch" lists
3910 the possible architectures.
3912 *** Changes in GDB-4.16:
3914 * New native configurations
3916 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3917 M68K NetBSD m68k-*-netbsd*
3918 PowerPC AIX 4.x powerpc-*-aix*
3919 PowerPC MacOS powerpc-*-macos*
3920 PowerPC Windows NT powerpcle-*-cygwin32
3921 RS/6000 AIX 4.x rs6000-*-aix4*
3925 ARM with RDP protocol arm-*-*
3926 I960 with MON960 i960-*-coff
3927 MIPS VxWorks mips*-*-vxworks*
3928 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3929 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3931 Matra Sparclet sparclet-*-*
3935 The powerpc-eabi configuration now includes the PSIM simulator,
3936 contributed by Andrew Cagney, with assistance from Mike Meissner.
3937 PSIM is a very elaborate model of the PowerPC, including not only
3938 basic instruction set execution, but also details of execution unit
3939 performance and I/O hardware. See sim/ppc/README for more details.
3943 GDB now works with Solaris 2.5.
3945 * Windows 95/NT native
3947 GDB will now work as a native debugger on Windows 95 and Windows NT.
3948 To build it from source, you must use the "gnu-win32" environment,
3949 which uses a DLL to emulate enough of Unix to run the GNU tools.
3950 Further information, binaries, and sources are available at
3951 ftp.cygnus.com, under pub/gnu-win32.
3953 * dont-repeat command
3955 If a user-defined command includes the command `dont-repeat', then the
3956 command will not be repeated if the user just types return. This is
3957 useful if the command is time-consuming to run, so that accidental
3958 extra keystrokes don't run the same command many times.
3960 * Send break instead of ^C
3962 The standard remote protocol now includes an option to send a break
3963 rather than a ^C to the target in order to interrupt it. By default,
3964 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3966 * Remote protocol timeout
3968 The standard remote protocol includes a new variable `remotetimeout'
3969 that allows you to set the number of seconds before GDB gives up trying
3970 to read from the target. The default value is 2.
3972 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3974 By default GDB will automatically keep track of objects as they are
3975 loaded and unloaded by the dynamic linker. By using the command `set
3976 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3977 when shared library events occur, thus allowing you to set breakpoints
3978 in shared libraries which are explicitly loaded by the inferior.
3980 Note this feature does not work on hpux8. On hpux9 you must link
3981 /usr/lib/end.o into your program. This feature should work
3982 automatically on hpux10.
3984 * Irix 5.x hardware watchpoint support
3986 Irix 5 configurations now support the use of hardware watchpoints.
3988 * Mips protocol "SYN garbage limit"
3990 When debugging a Mips target using the `target mips' protocol, you
3991 may set the number of characters that GDB will ignore by setting
3992 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3993 every character. The default value is 1050.
3995 * Recording and replaying remote debug sessions
3997 If you set `remotelogfile' to the name of a file, gdb will write to it
3998 a recording of a remote debug session. This recording may then be
3999 replayed back to gdb using "gdbreplay". See gdbserver/README for
4000 details. This is useful when you have a problem with GDB while doing
4001 remote debugging; you can make a recording of the session and send it
4002 to someone else, who can then recreate the problem.
4004 * Speedups for remote debugging
4006 GDB includes speedups for downloading and stepping MIPS systems using
4007 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4008 and more efficient S-record downloading.
4010 * Memory use reductions and statistics collection
4012 GDB now uses less memory and reports statistics about memory usage.
4013 Try the `maint print statistics' command, for example.
4015 *** Changes in GDB-4.15:
4017 * Psymtabs for XCOFF
4019 The symbol reader for AIX GDB now uses partial symbol tables. This
4020 can greatly improve startup time, especially for large executables.
4022 * Remote targets use caching
4024 Remote targets now use a data cache to speed up communication with the
4025 remote side. The data cache could lead to incorrect results because
4026 it doesn't know about volatile variables, thus making it impossible to
4027 debug targets which use memory mapped I/O devices. `set remotecache
4028 off' turns the the data cache off.
4030 * Remote targets may have threads
4032 The standard remote protocol now includes support for multiple threads
4033 in the target system, using new protocol commands 'H' and 'T'. See
4034 gdb/remote.c for details.
4038 If GDB is configured with `--enable-netrom', then it will include
4039 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4040 acts as though it is a bank of ROM on the target board, but you can
4041 write into it over the network. GDB's support consists only of
4042 support for fast loading into the emulated ROM; to debug, you must use
4043 another protocol, such as standard remote protocol. The usual
4044 sequence is something like
4046 target nrom <netrom-hostname>
4048 target remote <netrom-hostname>:1235
4052 GDB now includes support for the Apple Macintosh, as a host only. It
4053 may be run as either an MPW tool or as a standalone application, and
4054 it can debug through the serial port. All the usual GDB commands are
4055 available, but to the target command, you must supply "serial" as the
4056 device type instead of "/dev/ttyXX". See mpw-README in the main
4057 directory for more information on how to build. The MPW configuration
4058 scripts */mpw-config.in support only a few targets, and only the
4059 mips-idt-ecoff target has been tested.
4063 GDB configuration now uses autoconf. This is not user-visible,
4064 but does simplify configuration and building.
4068 GDB now supports hpux10.
4070 *** Changes in GDB-4.14:
4072 * New native configurations
4074 x86 FreeBSD i[345]86-*-freebsd
4075 x86 NetBSD i[345]86-*-netbsd
4076 NS32k NetBSD ns32k-*-netbsd
4077 Sparc NetBSD sparc-*-netbsd
4081 A29K VxWorks a29k-*-vxworks
4082 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4083 CPU32 EST-300 emulator m68*-*-est*
4084 PowerPC ELF powerpc-*-elf
4087 * Alpha OSF/1 support for procfs
4089 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4090 possible to attach to running processes. As the mounting of the /proc
4091 filesystem is optional on the Alpha, GDB automatically determines
4092 the availability of /proc during startup. This can lead to problems
4093 if /proc is unmounted after GDB has been started.
4095 * Arguments to user-defined commands
4097 User commands may accept up to 10 arguments separated by whitespace.
4098 Arguments are accessed within the user command via $arg0..$arg9. A
4101 print $arg0 + $arg1 + $arg2
4103 To execute the command use:
4106 Defines the command "adder" which prints the sum of its three arguments.
4107 Note the arguments are text substitutions, so they may reference variables,
4108 use complex expressions, or even perform inferior function calls.
4110 * New `if' and `while' commands
4112 This makes it possible to write more sophisticated user-defined
4113 commands. Both commands take a single argument, which is the
4114 expression to evaluate, and must be followed by the commands to
4115 execute, one per line, if the expression is nonzero, the list being
4116 terminated by the word `end'. The `if' command list may include an
4117 `else' word, which causes the following commands to be executed only
4118 if the expression is zero.
4120 * Fortran source language mode
4122 GDB now includes partial support for Fortran 77. It will recognize
4123 Fortran programs and can evaluate a subset of Fortran expressions, but
4124 variables and functions may not be handled correctly. GDB will work
4125 with G77, but does not yet know much about symbols emitted by other
4128 * Better HPUX support
4130 Most debugging facilities now work on dynamic executables for HPPAs
4131 running hpux9 or later. You can attach to running dynamically linked
4132 processes, but by default the dynamic libraries will be read-only, so
4133 for instance you won't be able to put breakpoints in them. To change
4134 that behavior do the following before running the program:
4140 This will cause the libraries to be mapped private and read-write.
4141 To revert to the normal behavior, do this:
4147 You cannot set breakpoints or examine data in the library until after
4148 the library is loaded if the function/data symbols do not have
4151 GDB can now also read debug symbols produced by the HP C compiler on
4152 HPPAs (sorry, no C++, Fortran or 68k support).
4154 * Target byte order now dynamically selectable
4156 You can choose which byte order to use with a target system, via the
4157 commands "set endian big" and "set endian little", and you can see the
4158 current setting by using "show endian". You can also give the command
4159 "set endian auto", in which case GDB will use the byte order
4160 associated with the executable. Currently, only embedded MIPS
4161 configurations support dynamic selection of target byte order.
4163 * New DOS host serial code
4165 This version uses DPMI interrupts to handle buffered I/O, so you
4166 no longer need to run asynctsr when debugging boards connected to
4169 *** Changes in GDB-4.13:
4171 * New "complete" command
4173 This lists all the possible completions for the rest of the line, if it
4174 were to be given as a command itself. This is intended for use by emacs.
4176 * Trailing space optional in prompt
4178 "set prompt" no longer adds a space for you after the prompt you set. This
4179 allows you to set a prompt which ends in a space or one that does not.
4181 * Breakpoint hit counts
4183 "info break" now displays a count of the number of times the breakpoint
4184 has been hit. This is especially useful in conjunction with "ignore"; you
4185 can ignore a large number of breakpoint hits, look at the breakpoint info
4186 to see how many times the breakpoint was hit, then run again, ignoring one
4187 less than that number, and this will get you quickly to the last hit of
4190 * Ability to stop printing at NULL character
4192 "set print null-stop" will cause GDB to stop printing the characters of
4193 an array when the first NULL is encountered. This is useful when large
4194 arrays actually contain only short strings.
4196 * Shared library breakpoints
4198 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4199 breakpoints in shared libraries before the executable is run.
4201 * Hardware watchpoints
4203 There is a new hardware breakpoint for the watch command for sparclite
4204 targets. See gdb/sparclite/hw_breakpoint.note.
4206 Hardware watchpoints are also now supported under GNU/Linux.
4210 Annotations have been added. These are for use with graphical interfaces,
4211 and are still experimental. Currently only gdba.el uses these.
4213 * Improved Irix 5 support
4215 GDB now works properly with Irix 5.2.
4217 * Improved HPPA support
4219 GDB now works properly with the latest GCC and GAS.
4221 * New native configurations
4223 Sequent PTX4 i[34]86-sequent-ptx4
4224 HPPA running OSF/1 hppa*-*-osf*
4225 Atari TT running SVR4 m68*-*-sysv4*
4226 RS/6000 LynxOS rs6000-*-lynxos*
4230 OS/9000 i[34]86-*-os9k
4231 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4234 * Hitachi SH7000 and E7000-PC ICE support
4236 There is now support for communicating with the Hitachi E7000-PC ICE.
4237 This is available automatically when GDB is configured for the SH.
4241 As usual, a variety of small fixes and improvements, both generic
4242 and configuration-specific. See the ChangeLog for more detail.
4244 *** Changes in GDB-4.12:
4246 * Irix 5 is now supported
4250 GDB-4.12 on the HPPA has a number of changes which make it unable
4251 to debug the output from the currently released versions of GCC and
4252 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4253 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4254 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4257 *** Changes in GDB-4.11:
4259 * User visible changes:
4263 The "set remotedebug" option is now consistent between the mips remote
4264 target, remote targets using the gdb-specific protocol, UDI (AMD's
4265 debug protocol for the 29k) and the 88k bug monitor. It is now an
4266 integer specifying a debug level (normally 0 or 1, but 2 means more
4267 debugging info for the mips target).
4269 * DEC Alpha native support
4271 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4272 debug info, but GDB works fairly well with the DEC compiler and should
4273 work with a future GCC release. See the README file for a few
4274 Alpha-specific notes.
4276 * Preliminary thread implementation
4278 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4280 * LynxOS native and target support for 386
4282 This release has been hosted on LynxOS 2.2, and also can be configured
4283 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4286 * Improvements in C++ mangling/demangling.
4288 This release has much better g++ debugging, specifically in name
4289 mangling/demangling, virtual function calls, print virtual table,
4290 call methods, ...etc.
4292 *** Changes in GDB-4.10:
4294 * User visible changes:
4296 Remote debugging using the GDB-specific (`target remote') protocol now
4297 supports the `load' command. This is only useful if you have some
4298 other way of getting the stub to the target system, and you can put it
4299 somewhere in memory where it won't get clobbered by the download.
4301 Filename completion now works.
4303 When run under emacs mode, the "info line" command now causes the
4304 arrow to point to the line specified. Also, "info line" prints
4305 addresses in symbolic form (as well as hex).
4307 All vxworks based targets now support a user settable option, called
4308 vxworks-timeout. This option represents the number of seconds gdb
4309 should wait for responses to rpc's. You might want to use this if
4310 your vxworks target is, perhaps, a slow software simulator or happens
4311 to be on the far side of a thin network line.
4315 This release contains support for using a DEC alpha as a GDB host for
4316 cross debugging. Native alpha debugging is not supported yet.
4319 *** Changes in GDB-4.9:
4323 This is the first GDB release which is accompanied by a matching testsuite.
4324 The testsuite requires installation of dejagnu, which should be available
4325 via ftp from most sites that carry GNU software.
4329 'Cfront' style demangling has had its name changed to 'ARM' style, to
4330 emphasize that it was written from the specifications in the C++ Annotated
4331 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4332 disclaimers, it still generated too much confusion with users attempting to
4333 use gdb with AT&T cfront.
4337 GDB now uses a standard remote interface to a simulator library.
4338 So far, the library contains simulators for the Zilog Z8001/2, the
4339 Hitachi H8/300, H8/500 and Super-H.
4341 * New targets supported
4343 H8/300 simulator h8300-hitachi-hms or h8300hms
4344 H8/500 simulator h8500-hitachi-hms or h8500hms
4345 SH simulator sh-hitachi-hms or sh
4346 Z8000 simulator z8k-zilog-none or z8ksim
4347 IDT MIPS board over serial line mips-idt-ecoff
4349 Cross-debugging to GO32 targets is supported. It requires a custom
4350 version of the i386-stub.c module which is integrated with the
4351 GO32 memory extender.
4353 * New remote protocols
4355 MIPS remote debugging protocol.
4357 * New source languages supported
4359 This version includes preliminary support for Chill, a Pascal like language
4360 used by telecommunications companies. Chill support is also being integrated
4361 into the GNU compiler, but we don't know when it will be publically available.
4364 *** Changes in GDB-4.8:
4366 * HP Precision Architecture supported
4368 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4369 version of this support was available as a set of patches from the
4370 University of Utah. GDB does not support debugging of programs
4371 compiled with the HP compiler, because HP will not document their file
4372 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4373 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4375 Many problems in the preliminary version have been fixed.
4377 * Faster and better demangling
4379 We have improved template demangling and fixed numerous bugs in the GNU style
4380 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4381 character types (wchar_t) are now supported. Demangling of each symbol is now
4382 only done once, and is cached when the symbol table for a file is read in.
4383 This results in a small increase in memory usage for C programs, a moderate
4384 increase in memory usage for C++ programs, and a fantastic speedup in
4387 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4388 from the specifications in the Annotated Reference Manual, which AT&T's
4389 compiler does not actually implement.
4391 * G++ multiple inheritance compiler problem
4393 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4394 inheritance lattices was reworked to properly discover ambiguities. We
4395 recently found an example which causes this new algorithm to fail in a
4396 very subtle way, producing bad debug information for those classes.
4397 The file 'gcc.patch' (in this directory) can be applied to gcc to
4398 circumvent the problem. A future GCC release will contain a complete
4401 The previous G++ debug info problem (mentioned below for the gdb-4.7
4402 release) is fixed in gcc version 2.3.2.
4404 * Improved configure script
4406 The `configure' script will now attempt to guess your system type if
4407 you don't supply a host system type. The old scheme of supplying a
4408 host system triplet is preferable over using this. All the magic is
4409 done in the new `config.guess' script. Examine it for details.
4411 We have also brought our configure script much more in line with the FSF's
4412 version. It now supports the --with-xxx options. In particular,
4413 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4414 The resulting GDB will not be able to read arbitrary object file formats --
4415 only the format ``expected'' to be used on the configured target system.
4416 We hope to make this the default in a future release.
4418 * Documentation improvements
4420 There's new internal documentation on how to modify GDB, and how to
4421 produce clean changes to the code. We implore people to read it
4422 before submitting changes.
4424 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4425 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4426 `info' files are also provided. To build `info' files from scratch,
4427 you will need the latest `makeinfo' release, which will be available in
4428 a future texinfo-X.Y release.
4430 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4431 We're not sure exactly which versions have this problem, but it has
4432 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4433 or better. If that isn't possible, there is a patch in
4434 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4435 around this problem.
4439 GDB now supports array constants that can be used in expressions typed in by
4440 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4441 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4444 The new directory `gdb/sparclite' contains a program that demonstrates
4445 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4447 * New native hosts supported
4449 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4450 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4452 * New targets supported
4454 AMD 29k family via UDI a29k-amd-udi or udi29k
4456 * New file formats supported
4458 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4459 HPUX core files, and SCO 3.2v2 core files.
4463 Attaching to processes now works again; thanks for the many bug reports.
4465 We have also stomped on a bunch of core dumps caused by
4466 printf_filtered("%s") problems.
4468 We eliminated a copyright problem on the rpc and ptrace header files
4469 for VxWorks, which was discovered at the last minute during the 4.7
4470 release. You should now be able to build a VxWorks GDB.
4472 You can now interrupt gdb while an attached process is running. This
4473 will cause the attached process to stop, and give control back to GDB.
4475 We fixed problems caused by using too many file descriptors
4476 for reading symbols from object files and libraries. This was
4477 especially a problem for programs that used many (~100) shared
4480 The `step' command now only enters a subroutine if there is line number
4481 information for the subroutine. Otherwise it acts like the `next'
4482 command. Previously, `step' would enter subroutines if there was
4483 any debugging information about the routine. This avoids problems
4484 when using `cc -g1' on MIPS machines.
4486 * Internal improvements
4488 GDB's internal interfaces have been improved to make it easier to support
4489 debugging of multiple languages in the future.
4491 GDB now uses a common structure for symbol information internally.
4492 Minimal symbols (derived from linkage symbols in object files), partial
4493 symbols (from a quick scan of debug information), and full symbols
4494 contain a common subset of information, making it easier to write
4495 shared code that handles any of them.
4497 * New command line options
4499 We now accept --silent as an alias for --quiet.
4503 The memory-mapped-malloc library is now licensed under the GNU Library
4504 General Public License.
4506 *** Changes in GDB-4.7:
4508 * Host/native/target split
4510 GDB has had some major internal surgery to untangle the support for
4511 hosts and remote targets. Now, when you configure GDB for a remote
4512 target, it will no longer load in all of the support for debugging
4513 local programs on the host. When fully completed and tested, this will
4514 ensure that arbitrary host/target combinations are possible.
4516 The primary conceptual shift is to separate the non-portable code in
4517 GDB into three categories. Host specific code is required any time GDB
4518 is compiled on that host, regardless of the target. Target specific
4519 code relates to the peculiarities of the target, but can be compiled on
4520 any host. Native specific code is everything else: it can only be
4521 built when the host and target are the same system. Child process
4522 handling and core file support are two common `native' examples.
4524 GDB's use of /proc for controlling Unix child processes is now cleaner.
4525 It has been split out into a single module under the `target_ops' vector,
4526 plus two native-dependent functions for each system that uses /proc.
4528 * New hosts supported
4530 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4531 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4532 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4534 * New targets supported
4536 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4537 68030 and CPU32 m68030-*-*, m68332-*-*
4539 * New native hosts supported
4541 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4542 (386bsd is not well tested yet)
4543 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4545 * New file formats supported
4547 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4548 supports reading of `a.out.adobe' object files, which are an a.out
4549 format extended with minimal information about multiple sections.
4553 `show copying' is the same as the old `info copying'.
4554 `show warranty' is the same as `info warrantee'.
4555 These were renamed for consistency. The old commands continue to work.
4557 `info handle' is a new alias for `info signals'.
4559 You can now define pre-command hooks, which attach arbitrary command
4560 scripts to any command. The commands in the hook will be executed
4561 prior to the user's command. You can also create a hook which will be
4562 executed whenever the program stops. See gdb.texinfo.
4566 We now deal with Cfront style name mangling, and can even extract type
4567 info from mangled symbols. GDB can automatically figure out which
4568 symbol mangling style your C++ compiler uses.
4570 Calling of methods and virtual functions has been improved as well.
4574 The crash that occured when debugging Sun Ansi-C compiled binaries is
4575 fixed. This was due to mishandling of the extra N_SO stabs output
4578 We also finally got Ultrix 4.2 running in house, and fixed core file
4579 support, with help from a dozen people on the net.
4581 John M. Farrell discovered that the reason that single-stepping was so
4582 slow on all of the Mips based platforms (primarily SGI and DEC) was
4583 that we were trying to demangle and lookup a symbol used for internal
4584 purposes on every instruction that was being stepped through. Changing
4585 the name of that symbol so that it couldn't be mistaken for a C++
4586 mangled symbol sped things up a great deal.
4588 Rich Pixley sped up symbol lookups in general by getting much smarter
4589 about when C++ symbol mangling is necessary. This should make symbol
4590 completion (TAB on the command line) much faster. It's not as fast as
4591 we'd like, but it's significantly faster than gdb-4.6.
4595 A new user controllable variable 'call_scratch_address' can
4596 specify the location of a scratch area to be used when GDB
4597 calls a function in the target. This is necessary because the
4598 usual method of putting the scratch area on the stack does not work
4599 in systems that have separate instruction and data spaces.
4601 We integrated changes to support the 29k UDI (Universal Debugger
4602 Interface), but discovered at the last minute that we didn't have all
4603 of the appropriate copyright paperwork. We are working with AMD to
4604 resolve this, and hope to have it available soon.
4608 We have sped up the remote serial line protocol, especially for targets
4609 with lots of registers. It now supports a new `expedited status' ('T')
4610 message which can be used in place of the existing 'S' status message.
4611 This allows the remote stub to send only the registers that GDB
4612 needs to make a quick decision about single-stepping or conditional
4613 breakpoints, eliminating the need to fetch the entire register set for
4614 each instruction being stepped through.
4616 The GDB remote serial protocol now implements a write-through cache for
4617 registers, only re-reading the registers if the target has run.
4619 There is also a new remote serial stub for SPARC processors. You can
4620 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4621 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4622 processor with a serial port.
4626 Configure.in files have become much easier to read and modify. A new
4627 `table driven' format makes it more obvious what configurations are
4628 supported, and what files each one uses.
4632 There is a new opcodes library which will eventually contain all of the
4633 disassembly routines and opcode tables. At present, it only contains
4634 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4635 disassembler (binutils/objdump) to share these routines.
4637 The libiberty library is now copylefted under the GNU Library General
4638 Public License. This allows more liberal use, and was done so libg++
4639 can use it. This makes no difference to GDB, since the Library License
4640 grants all the rights from the General Public License.
4644 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4645 reference to the stabs symbol info used by the debugger. It is (as far
4646 as we know) the only published document on this fascinating topic. We
4647 encourage you to read it, compare it to the stabs information on your
4648 system, and send improvements on the document in general (to
4649 bug-gdb@prep.ai.mit.edu).
4651 And, of course, many bugs have been fixed.
4654 *** Changes in GDB-4.6:
4656 * Better support for C++ function names
4658 GDB now accepts as input the "demangled form" of C++ overloaded function
4659 names and member function names, and can do command completion on such names
4660 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4661 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4662 Make use of command completion, it is your friend.
4664 GDB also now accepts a variety of C++ mangled symbol formats. They are
4665 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4666 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4667 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4668 for the list of formats.
4670 * G++ symbol mangling problem
4672 Recent versions of gcc have a bug in how they emit debugging information for
4673 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4674 directory) can be applied to gcc to fix the problem. Alternatively, if you
4675 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4676 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4677 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4680 * New 'maintenance' command
4682 All of the commands related to hacking GDB internals have been moved out of
4683 the main command set, and now live behind the 'maintenance' command. This
4684 can also be abbreviated as 'mt'. The following changes were made:
4686 dump-me -> maintenance dump-me
4687 info all-breakpoints -> maintenance info breakpoints
4688 printmsyms -> maintenance print msyms
4689 printobjfiles -> maintenance print objfiles
4690 printpsyms -> maintenance print psymbols
4691 printsyms -> maintenance print symbols
4693 The following commands are new:
4695 maintenance demangle Call internal GDB demangler routine to
4696 demangle a C++ link name and prints the result.
4697 maintenance print type Print a type chain for a given symbol
4699 * Change to .gdbinit file processing
4701 We now read the $HOME/.gdbinit file before processing the argv arguments
4702 (e.g. reading symbol files or core files). This allows global parameters to
4703 be set, which will apply during the symbol reading. The ./.gdbinit is still
4704 read after argv processing.
4706 * New hosts supported
4708 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4710 GNU/Linux support i386-unknown-linux or linux
4712 We are also including code to support the HP/PA running BSD and HPUX. This
4713 is almost guaranteed not to work, as we didn't have time to test or build it
4714 for this release. We are including it so that the more adventurous (or
4715 masochistic) of you can play with it. We also had major problems with the
4716 fact that the compiler that we got from HP doesn't support the -g option.
4719 * New targets supported
4721 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4723 * More smarts about finding #include files
4725 GDB now remembers the compilation directory for all include files, and for
4726 all files from which C is generated (like yacc and lex sources). This
4727 greatly improves GDB's ability to find yacc/lex sources, and include files,
4728 especially if you are debugging your program from a directory different from
4729 the one that contains your sources.
4731 We also fixed a bug which caused difficulty with listing and setting
4732 breakpoints in include files which contain C code. (In the past, you had to
4733 try twice in order to list an include file that you hadn't looked at before.)
4735 * Interesting infernals change
4737 GDB now deals with arbitrary numbers of sections, where the symbols for each
4738 section must be relocated relative to that section's landing place in the
4739 target's address space. This work was needed to support ELF with embedded
4740 stabs used by Solaris-2.0.
4742 * Bug fixes (of course!)
4744 There have been loads of fixes for the following things:
4745 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4746 i960, stabs, DOS(GO32), procfs, etc...
4748 See the ChangeLog for details.
4750 *** Changes in GDB-4.5:
4752 * New machines supported (host and target)
4754 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4756 SGI Irix-4.x mips-sgi-irix4 or iris4
4758 * New malloc package
4760 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4761 Mmalloc is capable of handling mutiple heaps of memory. It is also
4762 capable of saving a heap to a file, and then mapping it back in later.
4763 This can be used to greatly speedup the startup of GDB by using a
4764 pre-parsed symbol table which lives in a mmalloc managed heap. For
4765 more details, please read mmalloc/mmalloc.texi.
4769 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4770 'help info proc' for details.
4772 * MIPS ecoff symbol table format
4774 The code that reads MIPS symbol table format is now supported on all hosts.
4775 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4778 * File name changes for MS-DOS
4780 Many files in the config directories have been renamed to make it easier to
4781 support GDB on MS-DOSe systems (which have very restrictive file name
4782 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4783 environment) is close to working but has some remaining problems. Note
4784 that debugging of DOS programs is not supported, due to limitations
4785 in the ``operating system'', but it can be used to host cross-debugging.
4787 * Cross byte order fixes
4789 Many fixes have been made to support cross debugging of Sparc and MIPS
4790 targets from hosts whose byte order differs.
4792 * New -mapped and -readnow options
4794 If memory-mapped files are available on your system through the 'mmap'
4795 system call, you can use the -mapped option on the `file' or
4796 `symbol-file' commands to cause GDB to write the symbols from your
4797 program into a reusable file. If the program you are debugging is
4798 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4799 Future GDB debugging sessions will notice the presence of this file,
4800 and will quickly map in symbol information from it, rather than reading
4801 the symbol table from the executable program. Using the '-mapped'
4802 option in a GDB `file' or `symbol-file' command has the same effect as
4803 starting GDB with the '-mapped' command-line option.
4805 You can cause GDB to read the entire symbol table immediately by using
4806 the '-readnow' option with any of the commands that load symbol table
4807 information (or on the GDB command line). This makes the command
4808 slower, but makes future operations faster.
4810 The -mapped and -readnow options are typically combined in order to
4811 build a `fred.syms' file that contains complete symbol information.
4812 A simple GDB invocation to do nothing but build a `.syms' file for future
4815 gdb -batch -nx -mapped -readnow programname
4817 The `.syms' file is specific to the host machine on which GDB is run.
4818 It holds an exact image of GDB's internal symbol table. It cannot be
4819 shared across multiple host platforms.
4821 * longjmp() handling
4823 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4824 siglongjmp() without losing control. This feature has not yet been ported to
4825 all systems. It currently works on many 386 platforms, all MIPS-based
4826 platforms (SGI, DECstation, etc), and Sun3/4.
4830 Preliminary work has been put in to support the new Solaris OS from Sun. At
4831 this time, it can control and debug processes, but it is not capable of
4836 As always, many many bug fixes. The major areas were with g++, and mipsread.
4837 People using the MIPS-based platforms should experience fewer mysterious
4838 crashes and trashed symbol tables.
4840 *** Changes in GDB-4.4:
4842 * New machines supported (host and target)
4844 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4846 BSD Reno on Vax vax-dec-bsd
4847 Ultrix on Vax vax-dec-ultrix
4849 * New machines supported (target)
4851 AMD 29000 embedded, using EBMON a29k-none-none
4855 GDB continues to improve its handling of C++. `References' work better.
4856 The demangler has also been improved, and now deals with symbols mangled as
4857 per the Annotated C++ Reference Guide.
4859 GDB also now handles `stabs' symbol information embedded in MIPS
4860 `ecoff' symbol tables. Since the ecoff format was not easily
4861 extensible to handle new languages such as C++, this appeared to be a
4862 good way to put C++ debugging info into MIPS binaries. This option
4863 will be supported in the GNU C compiler, version 2, when it is
4866 * New features for SVR4
4868 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4869 shared libraries. Debugging dynamically linked programs should present
4870 only minor differences from debugging statically linked programs.
4872 The `info proc' command will print out information about any process
4873 on an SVR4 system (including the one you are debugging). At the moment,
4874 it prints the address mappings of the process.
4876 If you bring up GDB on another SVR4 system, please send mail to
4877 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4879 * Better dynamic linking support in SunOS
4881 Reading symbols from shared libraries which contain debugging symbols
4882 now works properly. However, there remain issues such as automatic
4883 skipping of `transfer vector' code during function calls, which
4884 make it harder to debug code in a shared library, than to debug the
4885 same code linked statically.
4889 GDB is now using the latest `getopt' routines from the FSF. This
4890 version accepts the -- prefix for options with long names. GDB will
4891 continue to accept the old forms (-option and +option) as well.
4892 Various single letter abbreviations for options have been explicity
4893 added to the option table so that they won't get overshadowed in the
4894 future by other options that begin with the same letter.
4898 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4899 Many assorted bugs have been handled. Many more remain to be handled.
4900 See the various ChangeLog files (primarily in gdb and bfd) for details.
4903 *** Changes in GDB-4.3:
4905 * New machines supported (host and target)
4907 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4908 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4909 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4911 * Almost SCO Unix support
4913 We had hoped to support:
4914 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4915 (except for core file support), but we discovered very late in the release
4916 that it has problems with process groups that render gdb unusable. Sorry
4917 about that. I encourage people to fix it and post the fixes.
4919 * Preliminary ELF and DWARF support
4921 GDB can read ELF object files on System V Release 4, and can handle
4922 debugging records for C, in DWARF format, in ELF files. This support
4923 is preliminary. If you bring up GDB on another SVR4 system, please
4924 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4929 GDB now uses the latest `readline' library. One user-visible change
4930 is that two tabs will list possible command completions, which previously
4931 required typing M-? (meta-question mark, or ESC ?).
4935 The `stepi' bug that many of you noticed has been squashed.
4936 Many bugs in C++ have been handled. Many more remain to be handled.
4937 See the various ChangeLog files (primarily in gdb and bfd) for details.
4939 * State of the MIPS world (in case you wondered):
4941 GDB can understand the symbol tables emitted by the compilers
4942 supplied by most vendors of MIPS-based machines, including DEC. These
4943 symbol tables are in a format that essentially nobody else uses.
4945 Some versions of gcc come with an assembler post-processor called
4946 mips-tfile. This program is required if you want to do source-level
4947 debugging of gcc-compiled programs. I believe FSF does not ship
4948 mips-tfile with gcc version 1, but it will eventually come with gcc
4951 Debugging of g++ output remains a problem. g++ version 1.xx does not
4952 really support it at all. (If you're lucky, you should be able to get
4953 line numbers and stack traces to work, but no parameters or local
4954 variables.) With some work it should be possible to improve the
4957 When gcc version 2 is released, you will have somewhat better luck.
4958 However, even then you will get confusing results for inheritance and
4961 We will eventually provide full debugging of g++ output on
4962 DECstations. This will probably involve some kind of stabs-in-ecoff
4963 encapulation, but the details have not been worked out yet.
4966 *** Changes in GDB-4.2:
4968 * Improved configuration
4970 Only one copy of `configure' exists now, and it is not self-modifying.
4971 Porting BFD is simpler.
4975 The `step' and `next' commands now only stop at the first instruction
4976 of a source line. This prevents the multiple stops that used to occur
4977 in switch statements, for-loops, etc. `Step' continues to stop if a
4978 function that has debugging information is called within the line.
4982 Lots of small bugs fixed. More remain.
4984 * New host supported (not target)
4986 Intel 386 PC clone running Mach i386-none-mach
4989 *** Changes in GDB-4.1:
4991 * Multiple source language support
4993 GDB now has internal scaffolding to handle several source languages.
4994 It determines the type of each source file from its filename extension,
4995 and will switch expression parsing and number formatting to match the
4996 language of the function in the currently selected stack frame.
4997 You can also specifically set the language to be used, with
4998 `set language c' or `set language modula-2'.
5002 GDB now has preliminary support for the GNU Modula-2 compiler,
5003 currently under development at the State University of New York at
5004 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5005 continue through the fall of 1991 and into 1992.
5007 Other Modula-2 compilers are currently not supported, and attempting to
5008 debug programs compiled with them will likely result in an error as the
5009 symbol table is read. Feel free to work on it, though!
5011 There are hooks in GDB for strict type checking and range checking,
5012 in the `Modula-2 philosophy', but they do not currently work.
5016 GDB can now write to executable and core files (e.g. patch
5017 a variable's value). You must turn this switch on, specify
5018 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5019 by assigning a new value to a variable. Modifications take
5022 * Automatic SunOS shared library reading
5024 When you run your program, GDB automatically determines where its
5025 shared libraries (if any) have been loaded, and reads their symbols.
5026 The `share' command is no longer needed. This also works when
5027 examining core files.
5031 You can specify the number of lines that the `list' command shows.
5034 * New machines supported (host and target)
5036 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5037 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5038 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5040 * New hosts supported (not targets)
5042 IBM RT/PC: romp-ibm-aix or rtpc
5044 * New targets supported (not hosts)
5046 AMD 29000 embedded with COFF a29k-none-coff
5047 AMD 29000 embedded with a.out a29k-none-aout
5048 Ultracomputer remote kernel debug a29k-nyu-kern
5050 * New remote interfaces
5056 *** Changes in GDB-4.0:
5060 Wide output is wrapped at good places to make the output more readable.
5062 Gdb now supports cross-debugging from a host machine of one type to a
5063 target machine of another type. Communication with the target system
5064 is over serial lines. The ``target'' command handles connecting to the
5065 remote system; the ``load'' command will download a program into the
5066 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5067 also supports debugging of realtime processes running under VxWorks,
5068 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5069 stub on the target system.
5071 New CPUs supported include the AMD 29000 and Intel 960.
5073 GDB now reads object files and symbol tables via a ``binary file''
5074 library, which allows a single copy of GDB to debug programs of multiple
5075 object file types such as a.out and coff.
5077 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5078 refcard.dvi and refcard.ps are available to format it).
5081 * Control-Variable user interface simplified
5083 All variables that control the operation of the debugger can be set
5084 by the ``set'' command, and displayed by the ``show'' command.
5086 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5087 ``Show prompt'' produces the response:
5088 Gdb's prompt is new-gdb=>.
5090 What follows are the NEW set commands. The command ``help set'' will
5091 print a complete list of old and new set commands. ``help set FOO''
5092 will give a longer description of the variable FOO. ``show'' will show
5093 all of the variable descriptions and their current settings.
5095 confirm on/off: Enables warning questions for operations that are
5096 hard to recover from, e.g. rerunning the program while
5097 it is already running. Default is ON.
5099 editing on/off: Enables EMACS style command line editing
5100 of input. Previous lines can be recalled with
5101 control-P, the current line can be edited with control-B,
5102 you can search for commands with control-R, etc.
5105 history filename NAME: NAME is where the gdb command history
5106 will be stored. The default is .gdb_history,
5107 or the value of the environment variable
5110 history size N: The size, in commands, of the command history. The
5111 default is 256, or the value of the environment variable
5114 history save on/off: If this value is set to ON, the history file will
5115 be saved after exiting gdb. If set to OFF, the
5116 file will not be saved. The default is OFF.
5118 history expansion on/off: If this value is set to ON, then csh-like
5119 history expansion will be performed on
5120 command line input. The default is OFF.
5122 radix N: Sets the default radix for input and output. It can be set
5123 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5124 in the current radix, so "set radix 10" is always a no-op.
5126 height N: This integer value is the number of lines on a page. Default
5127 is 24, the current `stty rows'' setting, or the ``li#''
5128 setting from the termcap entry matching the environment
5131 width N: This integer value is the number of characters on a line.
5132 Default is 80, the current `stty cols'' setting, or the ``co#''
5133 setting from the termcap entry matching the environment
5136 Note: ``set screensize'' is obsolete. Use ``set height'' and
5137 ``set width'' instead.
5139 print address on/off: Print memory addresses in various command displays,
5140 such as stack traces and structure values. Gdb looks
5141 more ``symbolic'' if you turn this off; it looks more
5142 ``machine level'' with it on. Default is ON.
5144 print array on/off: Prettyprint arrays. New convenient format! Default
5147 print demangle on/off: Print C++ symbols in "source" form if on,
5150 print asm-demangle on/off: Same, for assembler level printouts
5153 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5156 * Support for Epoch Environment.
5158 The epoch environment is a version of Emacs v18 with windowing. One
5159 new command, ``inspect'', is identical to ``print'', except that if you
5160 are running in the epoch environment, the value is printed in its own
5164 * Support for Shared Libraries
5166 GDB can now debug programs and core files that use SunOS shared libraries.
5167 Symbols from a shared library cannot be referenced
5168 before the shared library has been linked with the program (this
5169 happens after you type ``run'' and before the function main() is entered).
5170 At any time after this linking (including when examining core files
5171 from dynamically linked programs), gdb reads the symbols from each
5172 shared library when you type the ``sharedlibrary'' command.
5173 It can be abbreviated ``share''.
5175 sharedlibrary REGEXP: Load shared object library symbols for files
5176 matching a unix regular expression. No argument
5177 indicates to load symbols for all shared libraries.
5179 info sharedlibrary: Status of loaded shared libraries.
5184 A watchpoint stops execution of a program whenever the value of an
5185 expression changes. Checking for this slows down execution
5186 tremendously whenever you are in the scope of the expression, but is
5187 quite useful for catching tough ``bit-spreader'' or pointer misuse
5188 problems. Some machines such as the 386 have hardware for doing this
5189 more quickly, and future versions of gdb will use this hardware.
5191 watch EXP: Set a watchpoint (breakpoint) for an expression.
5193 info watchpoints: Information about your watchpoints.
5195 delete N: Deletes watchpoint number N (same as breakpoints).
5196 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5197 enable N: Re-enables watchpoint number N (same as breakpoints).
5200 * C++ multiple inheritance
5202 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5205 * C++ exception handling
5207 Gdb now supports limited C++ exception handling. Besides the existing
5208 ability to breakpoint on an exception handler, gdb can breakpoint on
5209 the raising of an exception (before the stack is peeled back to the
5212 catch FOO: If there is a FOO exception handler in the dynamic scope,
5213 set a breakpoint to catch exceptions which may be raised there.
5214 Multiple exceptions (``catch foo bar baz'') may be caught.
5216 info catch: Lists all exceptions which may be caught in the
5217 current stack frame.
5220 * Minor command changes
5222 The command ``call func (arg, arg, ...)'' now acts like the print
5223 command, except it does not print or save a value if the function's result
5224 is void. This is similar to dbx usage.
5226 The ``up'' and ``down'' commands now always print the frame they end up
5227 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5228 frames without printing.
5230 * New directory command
5232 'dir' now adds directories to the FRONT of the source search path.
5233 The path starts off empty. Source files that contain debug information
5234 about the directory in which they were compiled can be found even
5235 with an empty path; Sun CC and GCC include this information. If GDB can't
5236 find your source file in the current directory, type "dir .".
5238 * Configuring GDB for compilation
5240 For normal use, type ``./configure host''. See README or gdb.texinfo
5243 GDB now handles cross debugging. If you are remotely debugging between
5244 two different machines, type ``./configure host -target=targ''.
5245 Host is the machine where GDB will run; targ is the machine
5246 where the program that you are debugging will run.