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.
108 set trace-buffer-size
109 show trace-buffer-size
110 Request target to change the size of trace buffer.
114 ** For the Renesas Super-H architecture, the "regs" command has been removed
115 (has been deprecated in GDB 7.5), and "info all-registers" should be used
120 set print type methods (on|off)
121 show print type methods
122 Control whether method declarations are displayed by "ptype".
123 The default is to show them.
125 set print type typedefs (on|off)
126 show print type typedefs
127 Control whether typedef definitions are displayed by "ptype".
128 The default is to show them.
130 set filename-display basename|relative|absolute
131 show filename-display
132 Control the way in which filenames is displayed.
133 The default is "relative", which preserves previous behavior.
137 ** Command parameter changes are now notified using new async record
138 "=cmd-param-changed".
139 ** Trace frame changes caused by command "tfind" are now notified using
140 new async record "=traceframe-changed".
141 ** The creation, deletion and modification of trace state variables
142 are now notified using new async records "=tsv-created",
143 "=tsv-deleted" and "=tsv-modified".
144 ** The start and stop of process record are now notified using new
145 async record "=record-started" and "=record-stopped".
146 ** Memory changes are now notified using new async record
148 ** The data-disassemble command response will include a "fullname" field
149 containing the absolute file name when GDB can determine it and source
151 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
152 command, to allow pattern filling of memory areas.
153 ** New commands "-catch-load"/"-catch-unload" added for intercepting
154 library load/unload events.
155 ** The response to breakpoint commands and breakpoint async records
156 includes an "installed" field containing a boolean state about each
157 non-pending tracepoint location is whether installed on target or not.
158 ** Output of the "-trace-status" command includes a "trace-file" field
159 containing the name of the trace file being examined. This field is
160 optional, and only present when examining a trace file.
162 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
163 You must have the LZMA library available when configuring GDB for this
164 feature to be enabled. For more information, see:
165 http://fedoraproject.org/wiki/Features/MiniDebugInfo
170 Set the size of trace buffer. The remote stub reports support for this
171 packet to gdb's qSupported query.
173 *** Changes in GDB 7.5
175 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
176 for more x32 ABI info.
178 * GDB now supports access to MIPS DSP registers on Linux targets.
180 * GDB now supports debugging microMIPS binaries.
182 * The "info os" command on GNU/Linux can now display information on
183 several new classes of objects managed by the operating system:
184 "info os procgroups" lists process groups
185 "info os files" lists file descriptors
186 "info os sockets" lists internet-domain sockets
187 "info os shm" lists shared-memory regions
188 "info os semaphores" lists semaphores
189 "info os msg" lists message queues
190 "info os modules" lists loaded kernel modules
192 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
193 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
194 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
195 options and inspect the probe arguments using the new $_probe_arg family
196 of convenience variables. You can obtain more information about SystemTap
197 in <http://sourceware.org/systemtap/>.
199 * GDB now supports reversible debugging on ARM, it allows you to
200 debug basic ARM and THUMB instructions, and provides
201 record/replay support.
203 * The option "symbol-reloading" has been deleted as it is no longer used.
207 ** GDB commands implemented in Python can now be put in command class
210 ** The "maint set python print-stack on|off" is now deleted.
212 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
213 apply "flag enum"-style pretty-printing to any enum.
215 ** gdb.lookup_symbol can now work when there is no current frame.
217 ** gdb.Symbol now has a 'line' attribute, holding the line number in
218 the source at which the symbol was defined.
220 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
221 method 'value'. The former indicates whether the symbol needs a
222 frame in order to compute its value, and the latter computes the
225 ** A new method 'referenced_value' on gdb.Value objects which can
226 dereference pointer as well as C++ reference values.
228 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
229 which return the global and static blocks (as gdb.Block objects),
230 of the underlying symbol table, respectively.
232 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
233 object associated with a PC value.
235 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
236 of the address range occupied by code for the current source line.
238 * Go language support.
239 GDB now supports debugging programs written in the Go programming
242 * GDBserver now supports stdio connections.
243 E.g. (gdb) target remote | ssh myhost gdbserver - hello
245 * The binary "gdbtui" can no longer be built or installed.
246 Use "gdb -tui" instead.
248 * GDB will now print "flag" enums specially. A flag enum is one where
249 all the enumerator values have no bits in common when pairwise
250 "and"ed. When printing a value whose type is a flag enum, GDB will
251 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
252 (gdb) print (enum E) 3
255 * The filename part of a linespec will now match trailing components
256 of a source file name. For example, "break gcc/expr.c:1000" will
257 now set a breakpoint in build/gcc/expr.c, but not
260 * The "info proc" and "generate-core-file" commands will now also
261 work on remote targets connected to GDBserver on Linux.
263 * The command "info catch" has been removed. It has been disabled
266 * The "catch exception" and "catch assert" commands now accept
267 a condition at the end of the command, much like the "break"
268 command does. For instance:
270 (gdb) catch exception Constraint_Error if Barrier = True
272 Previously, it was possible to add a condition to such catchpoints,
273 but it had to be done as a second step, after the catchpoint had been
274 created, using the "condition" command.
276 * The "info static-tracepoint-marker" command will now also work on
277 native Linux targets with in-process agent.
279 * GDB can now set breakpoints on inlined functions.
281 * The .gdb_index section has been updated to include symbols for
282 inlined functions. GDB will ignore older .gdb_index sections by
283 default, which could cause symbol files to be loaded more slowly
284 until their .gdb_index sections can be recreated. The new command
285 "set use-deprecated-index-sections on" will cause GDB to use any older
286 .gdb_index sections it finds. This will restore performance, but the
287 ability to set breakpoints on inlined functions will be lost in symbol
288 files with older .gdb_index sections.
290 The .gdb_index section has also been updated to record more information
291 about each symbol. This speeds up the "info variables", "info functions"
292 and "info types" commands when used with programs having the .gdb_index
293 section, as well as speeding up debugging with shared libraries using
294 the .gdb_index section.
296 * Ada support for GDB/MI Variable Objects has been added.
298 * GDB can now support 'breakpoint always-inserted mode' in 'record'
303 ** New command -info-os is the MI equivalent of "info os".
305 ** Output logs ("set logging" and related) now include MI output.
309 ** "set use-deprecated-index-sections on|off"
310 "show use-deprecated-index-sections on|off"
311 Controls the use of deprecated .gdb_index sections.
313 ** "catch load" and "catch unload" can be used to stop when a shared
314 library is loaded or unloaded, respectively.
316 ** "enable count" can be used to auto-disable a breakpoint after
319 ** "info vtbl" can be used to show the virtual method tables for
320 C++ and Java objects.
322 ** "explore" and its sub commands "explore value" and "explore type"
323 can be used to reccursively explore values and types of
324 expressions. These commands are available only if GDB is
325 configured with '--with-python'.
327 ** "info auto-load" shows status of all kinds of auto-loaded files,
328 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
329 sequences of commands files, "info auto-load python-scripts"
330 shows status of auto-loading Python script files,
331 "info auto-load local-gdbinit" shows status of loading init file
332 (.gdbinit) from current directory and "info auto-load libthread-db" shows
333 status of inferior specific thread debugging shared library loading.
335 ** "info auto-load-scripts", "set auto-load-scripts on|off"
336 and "show auto-load-scripts" commands have been deprecated, use their
337 "info auto-load python-scripts", "set auto-load python-scripts on|off"
338 and "show auto-load python-scripts" counterparts instead.
340 ** "dprintf location,format,args..." creates a dynamic printf, which
341 is basically a breakpoint that does a printf and immediately
342 resumes your program's execution, so it is like a printf that you
343 can insert dynamically at runtime instead of at compiletime.
345 ** "set print symbol"
347 Controls whether GDB attempts to display the symbol, if any,
348 corresponding to addresses it prints. This defaults to "on", but
349 you can set it to "off" to restore GDB's previous behavior.
351 * Deprecated commands
353 ** For the Renesas Super-H architecture, the "regs" command has been
354 deprecated, and "info all-registers" should be used instead.
358 Renesas RL78 rl78-*-elf
359 HP OpenVMS ia64 ia64-hp-openvms*
361 * GDBserver supports evaluation of breakpoint conditions. When
362 support is advertised by GDBserver, GDB may be told to send the
363 breakpoint conditions in bytecode form to GDBserver. GDBserver
364 will only report the breakpoint trigger to GDB when its condition
370 show mips compression
371 Select the compressed ISA encoding used in functions that have no symbol
372 information available. The encoding can be set to either of:
375 and is updated automatically from ELF file flags if available.
377 set breakpoint condition-evaluation
378 show breakpoint condition-evaluation
379 Control whether breakpoint conditions are evaluated by GDB ("host") or by
380 GDBserver ("target"). Default option "auto" chooses the most efficient
382 This option can improve debugger efficiency depending on the speed of the
386 Disable auto-loading globally.
389 Show auto-loading setting of all kinds of auto-loaded files.
391 set auto-load gdb-scripts on|off
392 show auto-load gdb-scripts
393 Control auto-loading of GDB canned sequences of commands files.
395 set auto-load python-scripts on|off
396 show auto-load python-scripts
397 Control auto-loading of Python script files.
399 set auto-load local-gdbinit on|off
400 show auto-load local-gdbinit
401 Control loading of init file (.gdbinit) from current directory.
403 set auto-load libthread-db on|off
404 show auto-load libthread-db
405 Control auto-loading of inferior specific thread debugging shared library.
407 set auto-load scripts-directory <dir1>[:<dir2>...]
408 show auto-load scripts-directory
409 Set a list of directories from which to load auto-loaded scripts.
410 Automatically loaded Python scripts and GDB scripts are located in one
411 of the directories listed by this option.
412 The delimiter (':' above) may differ according to the host platform.
414 set auto-load safe-path <dir1>[:<dir2>...]
415 show auto-load safe-path
416 Set a list of directories from which it is safe to auto-load files.
417 The delimiter (':' above) may differ according to the host platform.
419 set debug auto-load on|off
421 Control display of debugging info for auto-loading the files above.
423 set dprintf-style gdb|call|agent
425 Control the way in which a dynamic printf is performed; "gdb"
426 requests a GDB printf command, while "call" causes dprintf to call a
427 function in the inferior. "agent" requests that the target agent
428 (such as GDBserver) do the printing.
430 set dprintf-function <expr>
431 show dprintf-function
432 set dprintf-channel <expr>
434 Set the function and optional first argument to the call when using
435 the "call" style of dynamic printf.
437 set disconnected-dprintf on|off
438 show disconnected-dprintf
439 Control whether agent-style dynamic printfs continue to be in effect
440 after GDB disconnects.
442 * New configure options
445 Configure default value for the 'set auto-load scripts-directory'
446 setting above. It defaults to '$debugdir:$datadir/auto-load',
447 $debugdir representing global debugging info directories (available
448 via 'show debug-file-directory') and $datadir representing GDB's data
449 directory (available via 'show data-directory').
451 --with-auto-load-safe-path
452 Configure default value for the 'set auto-load safe-path' setting
453 above. It defaults to the --with-auto-load-dir setting.
455 --without-auto-load-safe-path
456 Set 'set auto-load safe-path' to '/', effectively disabling this
461 z0/z1 conditional breakpoints extension
463 The z0/z1 breakpoint insertion packets have been extended to carry
464 a list of conditional expressions over to the remote stub depending on the
465 condition evaluation mode. The use of this extension can be controlled
466 via the "set remote conditional-breakpoints-packet" command.
470 Specify the signals which the remote stub may pass to the debugged
471 program without GDB involvement.
473 * New command line options
475 --init-command=FILE, -ix Like --command, -x but execute it
476 before loading inferior.
477 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
478 execute it before loading inferior.
480 *** Changes in GDB 7.4
482 * GDB now handles ambiguous linespecs more consistently; the existing
483 FILE:LINE support has been expanded to other types of linespecs. A
484 breakpoint will now be set on all matching locations in all
485 inferiors, and locations will be added or removed according to
488 * GDB now allows you to skip uninteresting functions and files when
489 stepping with the "skip function" and "skip file" commands.
491 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
492 and "show remote hardware-watchpoint-length-limit". These allows to
493 set or show the maximum length limit (in bytes) of a remote
494 target hardware watchpoint.
496 This allows e.g. to use "unlimited" hardware watchpoints with the
497 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
498 watchpoints are slower than real hardware watchpoints but are
499 significantly faster than gdb software watchpoints.
503 ** The register_pretty_printer function in module gdb.printing now takes
504 an optional `replace' argument. If True, the new printer replaces any
507 ** The "maint set python print-stack on|off" command has been
508 deprecated and will be deleted in GDB 7.5.
509 A new command: "set python print-stack none|full|message" has
510 replaced it. Additionally, the default for "print-stack" is
511 now "message", which just prints the error message without
514 ** A prompt substitution hook (prompt_hook) is now available to the
517 ** A new Python module, gdb.prompt has been added to the GDB Python
518 modules library. This module provides functionality for
519 escape sequences in prompts (used by set/show
520 extended-prompt). These escape sequences are replaced by their
523 ** Python commands and convenience-functions located in
524 'data-directory'/python/gdb/command and
525 'data-directory'/python/gdb/function are now automatically loaded
528 ** Blocks now provide four new attributes. global_block and
529 static_block will return the global and static blocks
530 respectively. is_static and is_global are boolean attributes
531 that indicate if the block is one of those two types.
533 ** Symbols now provide the "type" attribute, the type of the symbol.
535 ** The "gdb.breakpoint" function has been deprecated in favor of
538 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
539 of a function. This class is based on the "finish" command
540 available in the CLI.
542 ** Type objects for struct and union types now allow access to
543 the fields using standard Python dictionary (mapping) methods.
544 For example, "some_type['myfield']" now works, as does
547 ** A new event "gdb.new_objfile" has been added, triggered by loading a
550 ** A new function, "deep_items" has been added to the gdb.types
551 module in the GDB Python modules library. This function returns
552 an iterator over the fields of a struct or union type. Unlike
553 the standard Python "iteritems" method, it will recursively traverse
554 any anonymous fields.
558 ** "*stopped" events can report several new "reason"s, such as
561 ** Breakpoint changes are now notified using new async records, like
562 "=breakpoint-modified".
564 ** New command -ada-task-info.
566 * libthread-db-search-path now supports two special values: $sdir and $pdir.
567 $sdir specifies the default system locations of shared libraries.
568 $pdir specifies the directory where the libpthread used by the application
571 GDB no longer looks in $sdir and $pdir after it has searched the directories
572 mentioned in libthread-db-search-path. If you want to search those
573 directories, they must be specified in libthread-db-search-path.
574 The default value of libthread-db-search-path on GNU/Linux and Solaris
575 systems is now "$sdir:$pdir".
577 $pdir is not supported by gdbserver, it is currently ignored.
578 $sdir is supported by gdbserver.
580 * New configure option --with-iconv-bin.
581 When using the internationalization support like the one in the GNU C
582 library, GDB will invoke the "iconv" program to get a list of supported
583 character sets. If this program lives in a non-standard location, one can
584 use this option to specify where to find it.
586 * When natively debugging programs on PowerPC BookE processors running
587 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
588 watchpoints, which specify a mask in addition to an address to watch.
589 The mask specifies that some bits of an address (the bits which are
590 reset in the mask) should be ignored when matching the address accessed
591 by the inferior against the watchpoint address. See the "PowerPC Embedded"
592 section in the user manual for more details.
594 * The new option --once causes GDBserver to stop listening for connections once
595 the first connection is made. The listening port used by GDBserver will
596 become available after that.
598 * New commands "info macros" and "alias" have been added.
600 * New function parameters suffix @entry specifies value of function parameter
601 at the time the function got called. Entry values are available only since
607 "!" is now an alias of the "shell" command.
608 Note that no space is needed between "!" and SHELL COMMAND.
612 watch EXPRESSION mask MASK_VALUE
613 The watch command now supports the mask argument which allows creation
614 of masked watchpoints, if the current architecture supports this feature.
616 info auto-load-scripts [REGEXP]
617 This command was formerly named "maintenance print section-scripts".
618 It is now generally useful and is no longer a maintenance-only command.
620 info macro [-all] [--] MACRO
621 The info macro command has new options `-all' and `--'. The first for
622 printing all definitions of a macro. The second for explicitly specifying
623 the end of arguments and the beginning of the macro name in case the macro
624 name starts with a hyphen.
626 collect[/s] EXPRESSIONS
627 The tracepoint collect command now takes an optional modifier "/s"
628 that directs it to dereference pointer-to-character types and
629 collect the bytes of memory up to a zero byte. The behavior is
630 similar to what you see when you use the regular print command on a
631 string. An optional integer following the "/s" sets a bound on the
632 number of bytes that will be collected.
635 The trace start command now interprets any supplied arguments as a
636 note to be recorded with the trace run, with an effect similar to
637 setting the variable trace-notes.
640 The trace stop command now interprets any arguments as a note to be
641 mentioned along with the tstatus report that the trace was stopped
642 with a command. The effect is similar to setting the variable
645 * Tracepoints can now be enabled and disabled at any time after a trace
646 experiment has been started using the standard "enable" and "disable"
647 commands. It is now possible to start a trace experiment with no enabled
648 tracepoints; GDB will display a warning, but will allow the experiment to
649 begin, assuming that tracepoints will be enabled as needed while the trace
652 * Fast tracepoints on 32-bit x86-architectures can now be placed at
653 locations with 4-byte instructions, when they were previously
654 limited to locations with instructions of 5 bytes or longer.
658 set debug dwarf2-read
659 show debug dwarf2-read
660 Turns on or off display of debugging messages related to reading
661 DWARF debug info. The default is off.
663 set debug symtab-create
664 show debug symtab-create
665 Turns on or off display of debugging messages related to symbol table
666 creation. The default is off.
670 Set the GDB prompt, and allow escape sequences to be inserted to
671 display miscellaneous information (see 'help set extended-prompt'
672 for the list of sequences). This prompt (and any information
673 accessed through the escape sequences) is updated every time the
676 set print entry-values (both|compact|default|if-needed|no|only|preferred)
677 show print entry-values
678 Set printing of frame argument values at function entry. In some cases
679 GDB can determine the value of function argument which was passed by the
680 function caller, even if the value was modified inside the called function.
682 set debug entry-values
683 show debug entry-values
684 Control display of debugging info for determining frame argument values at
685 function entry and virtual tail call frames.
687 set basenames-may-differ
688 show basenames-may-differ
689 Set whether a source file may have multiple base names.
690 (A "base name" is the name of a file with the directory part removed.
691 Example: The base name of "/home/user/hello.c" is "hello.c".)
692 If set, GDB will canonicalize file names (e.g., expand symlinks)
693 before comparing them. Canonicalization is an expensive operation,
694 but it allows the same file be known by more than one base name.
695 If not set (the default), all source files are assumed to have just
696 one base name, and gdb will do file name comparisons more efficiently.
702 Set a user name and notes for the current and any future trace runs.
703 This is useful for long-running and/or disconnected traces, to
704 inform others (or yourself) as to who is running the trace, supply
705 contact information, or otherwise explain what is going on.
708 show trace-stop-notes
709 Set a note attached to the trace run, that is displayed when the
710 trace has been stopped by a tstop command. This is useful for
711 instance as an explanation, if you are stopping a trace run that was
712 started by someone else.
718 Dynamically enable a tracepoint in a started trace experiment.
722 Dynamically disable a tracepoint in a started trace experiment.
726 Set the user and notes of the trace run.
730 Query the current status of a tracepoint.
734 Query the minimum length of instruction at which a fast tracepoint may
737 * Dcache size (number of lines) and line-size are now runtime-configurable
738 via "set dcache line" and "set dcache line-size" commands.
742 Texas Instruments TMS320C6x tic6x-*-*
746 Renesas RL78 rl78-*-elf
748 *** Changes in GDB 7.3.1
750 * The build failure for NetBSD and OpenBSD targets have now been fixed.
752 *** Changes in GDB 7.3
754 * GDB has a new command: "thread find [REGEXP]".
755 It finds the thread id whose name, target id, or thread extra info
756 matches the given regular expression.
758 * The "catch syscall" command now works on mips*-linux* targets.
760 * The -data-disassemble MI command now supports modes 2 and 3 for
761 dumping the instruction opcodes.
763 * New command line options
765 -data-directory DIR Specify DIR as the "data-directory".
766 This is mostly for testing purposes.
768 * The "maint set python auto-load on|off" command has been renamed to
769 "set auto-load-scripts on|off".
771 * GDB has a new command: "set directories".
772 It is like the "dir" command except that it replaces the
773 source path list instead of augmenting it.
775 * GDB now understands thread names.
777 On GNU/Linux, "info threads" will display the thread name as set by
778 prctl or pthread_setname_np.
780 There is also a new command, "thread name", which can be used to
781 assign a name internally for GDB to display.
784 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
785 has been integrated into GDB.
789 ** The function gdb.Write now accepts an optional keyword 'stream'.
790 This keyword, when provided, will direct the output to either
791 stdout, stderr, or GDB's logging output.
793 ** Parameters can now be be sub-classed in Python, and in particular
794 you may implement the get_set_doc and get_show_doc functions.
795 This improves how Parameter set/show documentation is processed
796 and allows for more dynamic content.
798 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
799 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
800 have an is_valid method.
802 ** Breakpoints can now be sub-classed in Python, and in particular
803 you may implement a 'stop' function that is executed each time
804 the inferior reaches that breakpoint.
806 ** New function gdb.lookup_global_symbol looks up a global symbol.
808 ** GDB values in Python are now callable if the value represents a
809 function. For example, if 'some_value' represents a function that
810 takes two integer parameters and returns a value, you can call
811 that function like so:
813 result = some_value (10,20)
815 ** Module gdb.types has been added.
816 It contains a collection of utilities for working with gdb.Types objects:
817 get_basic_type, has_field, make_enum_dict.
819 ** Module gdb.printing has been added.
820 It contains utilities for writing and registering pretty-printers.
821 New classes: PrettyPrinter, SubPrettyPrinter,
822 RegexpCollectionPrettyPrinter.
823 New function: register_pretty_printer.
825 ** New commands "info pretty-printers", "enable pretty-printer" and
826 "disable pretty-printer" have been added.
828 ** gdb.parameter("directories") is now available.
830 ** New function gdb.newest_frame returns the newest frame in the
833 ** The gdb.InferiorThread class has a new "name" attribute. This
834 holds the thread's name.
836 ** Python Support for Inferior events.
837 Python scripts can add observers to be notified of events
838 occurring in the process being debugged.
839 The following events are currently supported:
840 - gdb.events.cont Continue event.
841 - gdb.events.exited Inferior exited event.
842 - gdb.events.stop Signal received, and Breakpoint hit events.
846 ** GDB now puts template parameters in scope when debugging in an
847 instantiation. For example, if you have:
849 template<int X> int func (void) { return X; }
851 then if you step into func<5>, "print X" will show "5". This
852 feature requires proper debuginfo support from the compiler; it
853 was added to GCC 4.5.
855 ** The motion commands "next", "finish", "until", and "advance" now
856 work better when exceptions are thrown. In particular, GDB will
857 no longer lose control of the inferior; instead, the GDB will
858 stop the inferior at the point at which the exception is caught.
859 This functionality requires a change in the exception handling
860 code that was introduced in GCC 4.5.
862 * GDB now follows GCC's rules on accessing volatile objects when
863 reading or writing target state during expression evaluation.
864 One notable difference to prior behavior is that "print x = 0"
865 no longer generates a read of x; the value of the assignment is
866 now always taken directly from the value being assigned.
868 * GDB now has some support for using labels in the program's source in
869 linespecs. For instance, you can use "advance label" to continue
870 execution to a label.
872 * GDB now has support for reading and writing a new .gdb_index
873 section. This section holds a fast index of DWARF debugging
874 information and can be used to greatly speed up GDB startup and
875 operation. See the documentation for `save gdb-index' for details.
877 * The "watch" command now accepts an optional "-location" argument.
878 When used, this causes GDB to watch the memory referred to by the
879 expression. Such a watchpoint is never deleted due to it going out
882 * GDB now supports thread debugging of core dumps on GNU/Linux.
884 GDB now activates thread debugging using the libthread_db library
885 when debugging GNU/Linux core dumps, similarly to when debugging
886 live processes. As a result, when debugging a core dump file, GDB
887 is now able to display pthread_t ids of threads. For example, "info
888 threads" shows the same output as when debugging the process when it
889 was live. In earlier releases, you'd see something like this:
892 * 1 LWP 6780 main () at main.c:10
894 While now you see this:
897 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
899 It is also now possible to inspect TLS variables when debugging core
902 When debugging a core dump generated on a machine other than the one
903 used to run GDB, you may need to point GDB at the correct
904 libthread_db library with the "set libthread-db-search-path"
905 command. See the user manual for more details on this command.
907 * When natively debugging programs on PowerPC BookE processors running
908 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
909 which stop execution of the inferior whenever it executes an instruction
910 at any address within the specified range. See the "PowerPC Embedded"
911 section in the user manual for more details.
913 * New features in the GDB remote stub, GDBserver
915 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
916 and i686 LynxOS (version 5.x).
918 ** GDBserver is now supported on Blackfin Linux.
920 * New native configurations
922 ia64 HP-UX ia64-*-hpux*
926 Analog Devices, Inc. Blackfin Processor bfin-*
928 * Ada task switching is now supported on sparc-elf targets when
929 debugging a program using the Ravenscar Profile. For more information,
930 see the "Tasking Support when using the Ravenscar Profile" section
931 in the GDB user manual.
933 * Guile support was removed.
935 * New features in the GNU simulator
937 ** The --map-info flag lists all known core mappings.
939 ** CFI flashes may be simulated via the "cfi" device.
941 *** Changes in GDB 7.2
943 * Shared library support for remote targets by default
945 When GDB is configured for a generic, non-OS specific target, like
946 for example, --target=arm-eabi or one of the many *-*-elf targets,
947 GDB now queries remote stubs for loaded shared libraries using the
948 `qXfer:libraries:read' packet. Previously, shared library support
949 was always disabled for such configurations.
953 ** Argument Dependent Lookup (ADL)
955 In C++ ADL lookup directs function search to the namespaces of its
956 arguments even if the namespace has not been imported.
966 Here the compiler will search for `foo' in the namespace of 'b'
967 and find A::foo. GDB now supports this. This construct is commonly
968 used in the Standard Template Library for operators.
970 ** Improved User Defined Operator Support
972 In addition to member operators, GDB now supports lookup of operators
973 defined in a namespace and imported with a `using' directive, operators
974 defined in the global scope, operators imported implicitly from an
975 anonymous namespace, and the ADL operators mentioned in the previous
977 GDB now also supports proper overload resolution for all the previously
978 mentioned flavors of operators.
980 ** static const class members
982 Printing of static const class members that are initialized in the
983 class definition has been fixed.
985 * Windows Thread Information Block access.
987 On Windows targets, GDB now supports displaying the Windows Thread
988 Information Block (TIB) structure. This structure is visible either
989 by using the new command `info w32 thread-information-block' or, by
990 dereferencing the new convenience variable named `$_tlb', a
991 thread-specific pointer to the TIB. This feature is also supported
992 when remote debugging using GDBserver.
996 Static tracepoints are calls in the user program into a tracing
997 library. One such library is a port of the LTTng kernel tracer to
998 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
999 When debugging with GDBserver, GDB now supports combining the GDB
1000 tracepoint machinery with such libraries. For example: the user can
1001 use GDB to probe a static tracepoint marker (a call from the user
1002 program into the tracing library) with the new "strace" command (see
1003 "New commands" below). This creates a "static tracepoint" in the
1004 breakpoint list, that can be manipulated with the same feature set
1005 as fast and regular tracepoints. E.g., collect registers, local and
1006 global variables, collect trace state variables, and define
1007 tracepoint conditions. In addition, the user can collect extra
1008 static tracepoint marker specific data, by collecting the new
1009 $_sdata internal variable. When analyzing the trace buffer, you can
1010 inspect $_sdata like any other variable available to GDB. For more
1011 information, see the "Tracepoints" chapter in GDB user manual. New
1012 remote packets have been defined to support static tracepoints, see
1013 the "New remote packets" section below.
1015 * Better reconstruction of tracepoints after disconnected tracing
1017 GDB will attempt to download the original source form of tracepoint
1018 definitions when starting a trace run, and then will upload these
1019 upon reconnection to the target, resulting in a more accurate
1020 reconstruction of the tracepoints that are in use on the target.
1024 You can now exercise direct control over the ways that GDB can
1025 affect your program. For instance, you can disallow the setting of
1026 breakpoints, so that the program can run continuously (assuming
1027 non-stop mode). In addition, the "observer" variable is available
1028 to switch all of the different controls; in observer mode, GDB
1029 cannot affect the target's behavior at all, which is useful for
1030 tasks like diagnosing live systems in the field.
1032 * The new convenience variable $_thread holds the number of the
1035 * New remote packets
1039 Return the address of the Windows Thread Information Block of a given thread.
1043 In response to several of the tracepoint packets, the target may now
1044 also respond with a number of intermediate `qRelocInsn' request
1045 packets before the final result packet, to have GDB handle
1046 relocating an instruction to execute at a different address. This
1047 is particularly useful for stubs that support fast tracepoints. GDB
1048 reports support for this feature in the qSupported packet.
1052 List static tracepoint markers in the target program.
1056 List static tracepoint markers at a given address in the target
1059 qXfer:statictrace:read
1061 Read the static trace data collected (by a `collect $_sdata'
1062 tracepoint action). The remote stub reports support for this packet
1063 to gdb's qSupported query.
1067 Send the current settings of GDB's permission flags.
1071 Send part of the source (textual) form of a tracepoint definition,
1072 which includes location, conditional, and action list.
1074 * The source command now accepts a -s option to force searching for the
1075 script in the source search path even if the script name specifies
1078 * New features in the GDB remote stub, GDBserver
1080 - GDBserver now support tracepoints (including fast tracepoints, and
1081 static tracepoints). The feature is currently supported by the
1082 i386-linux and amd64-linux builds. See the "Tracepoints support
1083 in gdbserver" section in the manual for more information.
1085 GDBserver JIT compiles the tracepoint's conditional agent
1086 expression bytecode into native code whenever possible for low
1087 overhead dynamic tracepoints conditionals. For such tracepoints,
1088 an expression that examines program state is evaluated when the
1089 tracepoint is reached, in order to determine whether to capture
1090 trace data. If the condition is simple and false, processing the
1091 tracepoint finishes very quickly and no data is gathered.
1093 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1094 for static tracepoints support.
1096 - GDBserver now supports x86_64 Windows 64-bit debugging.
1098 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1099 it understands register description.
1101 * The --batch flag now disables pagination and queries.
1103 * X86 general purpose registers
1105 GDB now supports reading/writing byte, word and double-word x86
1106 general purpose registers directly. This means you can use, say,
1107 $ah or $ax to refer, respectively, to the byte register AH and
1108 16-bit word register AX that are actually portions of the 32-bit
1109 register EAX or 64-bit register RAX.
1111 * The `commands' command now accepts a range of breakpoints to modify.
1112 A plain `commands' following a command that creates multiple
1113 breakpoints affects all the breakpoints set by that command. This
1114 applies to breakpoints set by `rbreak', and also applies when a
1115 single `break' command creates multiple breakpoints (e.g.,
1116 breakpoints on overloaded c++ functions).
1118 * The `rbreak' command now accepts a filename specification as part of
1119 its argument, limiting the functions selected by the regex to those
1120 in the specified file.
1122 * Support for remote debugging Windows and SymbianOS shared libraries
1123 from Unix hosts has been improved. Non Windows GDB builds now can
1124 understand target reported file names that follow MS-DOS based file
1125 system semantics, such as file names that include drive letters and
1126 use the backslash character as directory separator. This makes it
1127 possible to transparently use the "set sysroot" and "set
1128 solib-search-path" on Unix hosts to point as host copies of the
1129 target's shared libraries. See the new command "set
1130 target-file-system-kind" described below, and the "Commands to
1131 specify files" section in the user manual for more information.
1135 eval template, expressions...
1136 Convert the values of one or more expressions under the control
1137 of the string template to a command line, and call it.
1139 set target-file-system-kind unix|dos-based|auto
1140 show target-file-system-kind
1141 Set or show the assumed file system kind for target reported file
1144 save breakpoints <filename>
1145 Save all current breakpoint definitions to a file suitable for use
1146 in a later debugging session. To read the saved breakpoint
1147 definitions, use the `source' command.
1149 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1152 info static-tracepoint-markers
1153 Display information about static tracepoint markers in the target.
1155 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1156 Define a static tracepoint by probing a marker at the given
1157 function, line, address, or marker ID.
1161 Enable and disable observer mode.
1163 set may-write-registers on|off
1164 set may-write-memory on|off
1165 set may-insert-breakpoints on|off
1166 set may-insert-tracepoints on|off
1167 set may-insert-fast-tracepoints on|off
1168 set may-interrupt on|off
1169 Set individual permissions for GDB effects on the target. Note that
1170 some of these settings can have undesirable or surprising
1171 consequences, particularly when changed in the middle of a session.
1172 For instance, disabling the writing of memory can prevent
1173 breakpoints from being inserted, cause single-stepping to fail, or
1174 even crash your program, if you disable after breakpoints have been
1175 inserted. However, GDB should not crash.
1177 set record memory-query on|off
1178 show record memory-query
1179 Control whether to stop the inferior if memory changes caused
1180 by an instruction cannot be recorded.
1185 The disassemble command now supports "start,+length" form of two arguments.
1189 ** GDB now provides a new directory location, called the python directory,
1190 where Python scripts written for GDB can be installed. The location
1191 of that directory is <data-directory>/python, where <data-directory>
1192 is the GDB data directory. For more details, see section `Scripting
1193 GDB using Python' in the manual.
1195 ** The GDB Python API now has access to breakpoints, symbols, symbol
1196 tables, program spaces, inferiors, threads and frame's code blocks.
1197 Additionally, GDB Parameters can now be created from the API, and
1198 manipulated via set/show in the CLI.
1200 ** New functions gdb.target_charset, gdb.target_wide_charset,
1201 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1203 ** New exception gdb.GdbError.
1205 ** Pretty-printers are now also looked up in the current program space.
1207 ** Pretty-printers can now be individually enabled and disabled.
1209 ** GDB now looks for names of Python scripts to auto-load in a
1210 special section named `.debug_gdb_scripts', in addition to looking
1211 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1213 * Tracepoint actions were unified with breakpoint commands. In particular,
1214 there are no longer differences in "info break" output for breakpoints and
1215 tracepoints and the "commands" command can be used for both tracepoints and
1216 regular breakpoints.
1220 ARM Symbian arm*-*-symbianelf*
1222 * D language support.
1223 GDB now supports debugging programs written in the D programming
1226 * GDB now supports the extended ptrace interface for PowerPC which is
1227 available since Linux kernel version 2.6.34. This automatically enables
1228 any hardware breakpoints and additional hardware watchpoints available in
1229 the processor. The old ptrace interface exposes just one hardware
1230 watchpoint and no hardware breakpoints.
1232 * GDB is now able to use the Data Value Compare (DVC) register available on
1233 embedded PowerPC processors to implement in hardware simple watchpoint
1234 conditions of the form:
1236 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1238 This works in native GDB running on Linux kernels with the extended ptrace
1239 interface mentioned above.
1241 *** Changes in GDB 7.1
1245 ** Namespace Support
1247 GDB now supports importing of namespaces in C++. This enables the
1248 user to inspect variables from imported namespaces. Support for
1249 namepace aliasing has also been added. So, if a namespace is
1250 aliased in the current scope (e.g. namepace C=A; ) the user can
1251 print variables using the alias (e.g. (gdb) print C::x).
1255 All known bugs relating to the printing of virtual base class were
1256 fixed. It is now possible to call overloaded static methods using a
1261 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1262 and reinterpret_cast<> are now handled by the C++ expression parser.
1266 Xilinx MicroBlaze microblaze-*-*
1271 Xilinx MicroBlaze microblaze
1274 * Multi-program debugging.
1276 GDB now has support for multi-program (a.k.a. multi-executable or
1277 multi-exec) debugging. This allows for debugging multiple inferiors
1278 simultaneously each running a different program under the same GDB
1279 session. See "Debugging Multiple Inferiors and Programs" in the
1280 manual for more information. This implied some user visible changes
1281 in the multi-inferior support. For example, "info inferiors" now
1282 lists inferiors that are not running yet or that have exited
1283 already. See also "New commands" and "New options" below.
1285 * New tracing features
1287 GDB's tracepoint facility now includes several new features:
1289 ** Trace state variables
1291 GDB tracepoints now include support for trace state variables, which
1292 are variables managed by the target agent during a tracing
1293 experiment. They are useful for tracepoints that trigger each
1294 other, so for instance one tracepoint can count hits in a variable,
1295 and then a second tracepoint has a condition that is true when the
1296 count reaches a particular value. Trace state variables share the
1297 $-syntax of GDB convenience variables, and can appear in both
1298 tracepoint actions and condition expressions. Use the "tvariable"
1299 command to create, and "info tvariables" to view; see "Trace State
1300 Variables" in the manual for more detail.
1304 GDB now includes an option for defining fast tracepoints, which
1305 targets may implement more efficiently, such as by installing a jump
1306 into the target agent rather than a trap instruction. The resulting
1307 speedup can be by two orders of magnitude or more, although the
1308 tradeoff is that some program locations on some target architectures
1309 might not allow fast tracepoint installation, for instance if the
1310 instruction to be replaced is shorter than the jump. To request a
1311 fast tracepoint, use the "ftrace" command, with syntax identical to
1312 the regular trace command.
1314 ** Disconnected tracing
1316 It is now possible to detach GDB from the target while it is running
1317 a trace experiment, then reconnect later to see how the experiment
1318 is going. In addition, a new variable disconnected-tracing lets you
1319 tell the target agent whether to continue running a trace if the
1320 connection is lost unexpectedly.
1324 GDB now has the ability to save the trace buffer into a file, and
1325 then use that file as a target, similarly to you can do with
1326 corefiles. You can select trace frames, print data that was
1327 collected in them, and use tstatus to display the state of the
1328 tracing run at the moment that it was saved. To create a trace
1329 file, use "tsave <filename>", and to use it, do "target tfile
1332 ** Circular trace buffer
1334 You can ask the target agent to handle the trace buffer as a
1335 circular buffer, discarding the oldest trace frames to make room for
1336 newer ones, by setting circular-trace-buffer to on. This feature may
1337 not be available for all target agents.
1342 The disassemble command, when invoked with two arguments, now requires
1343 the arguments to be comma-separated.
1346 The info variables command now displays variable definitions. Files
1347 which only declare a variable are not shown.
1350 The source command is now capable of sourcing Python scripts.
1351 This feature is dependent on the debugger being build with Python
1354 Related to this enhancement is also the introduction of a new command
1355 "set script-extension" (see below).
1357 * New commands (for set/show, see "New options" below)
1359 record save [<FILENAME>]
1360 Save a file (in core file format) containing the process record
1361 execution log for replay debugging at a later time.
1363 record restore <FILENAME>
1364 Restore the process record execution log that was saved at an
1365 earlier time, for replay debugging.
1367 add-inferior [-copies <N>] [-exec <FILENAME>]
1370 clone-inferior [-copies <N>] [ID]
1371 Make a new inferior ready to execute the same program another
1372 inferior has loaded.
1377 maint info program-spaces
1378 List the program spaces loaded into GDB.
1380 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1381 show remote interrupt-sequence
1382 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1383 as the sequence to the remote target in order to interrupt the execution.
1384 Ctrl-C is a default. Some system prefers BREAK which is high level of
1385 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1386 Magic SysRq g. It is BREAK signal and character 'g'.
1388 set remote interrupt-on-connect [on | off]
1389 show remote interrupt-on-connect
1390 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1391 remote target when gdb connects to it. This is needed when you debug
1394 set remotebreak [on | off]
1396 Deprecated. Use "set/show remote interrupt-sequence" instead.
1398 tvariable $NAME [ = EXP ]
1399 Create or modify a trace state variable.
1402 List trace state variables and their values.
1404 delete tvariable $NAME ...
1405 Delete one or more trace state variables.
1408 Evaluate the given expressions without collecting anything into the
1409 trace buffer. (Valid in tracepoint actions only.)
1411 ftrace FN / FILE:LINE / *ADDR
1412 Define a fast tracepoint at the given function, line, or address.
1414 * New expression syntax
1416 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1417 GDB now parses 0b101010 identically with 42.
1421 set follow-exec-mode new|same
1422 show follow-exec-mode
1423 Control whether GDB reuses the same inferior across an exec call or
1424 creates a new one. This is useful to be able to restart the old
1425 executable after the inferior having done an exec call.
1427 set default-collect EXPR, ...
1428 show default-collect
1429 Define a list of expressions to be collected at each tracepoint.
1430 This is a useful way to ensure essential items are not overlooked,
1431 such as registers or a critical global variable.
1433 set disconnected-tracing
1434 show disconnected-tracing
1435 If set to 1, the target is instructed to continue tracing if it
1436 loses its connection to GDB. If 0, the target is to stop tracing
1439 set circular-trace-buffer
1440 show circular-trace-buffer
1441 If set to on, the target is instructed to use a circular trace buffer
1442 and discard the oldest trace frames instead of stopping the trace due
1443 to a full trace buffer. If set to off, the trace stops when the buffer
1444 fills up. Some targets may not support this.
1446 set script-extension off|soft|strict
1447 show script-extension
1448 If set to "off", the debugger does not perform any script language
1449 recognition, and all sourced files are assumed to be GDB scripts.
1450 If set to "soft" (the default), files are sourced according to
1451 filename extension, falling back to GDB scripts if the first
1453 If set to "strict", files are sourced according to filename extension.
1455 set ada trust-PAD-over-XVS on|off
1456 show ada trust-PAD-over-XVS
1457 If off, activate a workaround against a bug in the debugging information
1458 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1459 the GCC sources for more information about the GNAT encoding and
1460 PAD types in particular). It is always safe to set this option to
1461 off, but this introduces a slight performance penalty. The default
1464 * Python API Improvements
1466 ** GDB provides the new class gdb.LazyString. This is useful in
1467 some pretty-printing cases. The new method gdb.Value.lazy_string
1468 provides a simple way to create objects of this type.
1470 ** The fields returned by gdb.Type.fields now have an
1471 `is_base_class' attribute.
1473 ** The new method gdb.Type.range returns the range of an array type.
1475 ** The new method gdb.parse_and_eval can be used to parse and
1476 evaluate an expression.
1478 * New remote packets
1481 Define a trace state variable.
1484 Get the current value of a trace state variable.
1487 Set desired tracing behavior upon disconnection.
1490 Set the trace buffer to be linear or circular.
1493 Get data about the tracepoints currently in use.
1497 Process record now works correctly with hardware watchpoints.
1499 Multiple bug fixes have been made to the mips-irix port, making it
1500 much more reliable. In particular:
1501 - Debugging threaded applications is now possible again. Previously,
1502 GDB would hang while starting the program, or while waiting for
1503 the program to stop at a breakpoint.
1504 - Attaching to a running process no longer hangs.
1505 - An error occurring while loading a core file has been fixed.
1506 - Changing the value of the PC register now works again. This fixes
1507 problems observed when using the "jump" command, or when calling
1508 a function from GDB, or even when assigning a new value to $pc.
1509 - With the "finish" and "return" commands, the return value for functions
1510 returning a small array is now correctly printed.
1511 - It is now possible to break on shared library code which gets executed
1512 during a shared library init phase (code executed while executing
1513 their .init section). Previously, the breakpoint would have no effect.
1514 - GDB is now able to backtrace through the signal handler for
1515 non-threaded programs.
1517 PIE (Position Independent Executable) programs debugging is now supported.
1518 This includes debugging execution of PIC (Position Independent Code) shared
1519 libraries although for that, it should be possible to run such libraries as an
1522 *** Changes in GDB 7.0
1524 * GDB now has an interface for JIT compilation. Applications that
1525 dynamically generate code can create symbol files in memory and register
1526 them with GDB. For users, the feature should work transparently, and
1527 for JIT developers, the interface is documented in the GDB manual in the
1528 "JIT Compilation Interface" chapter.
1530 * Tracepoints may now be conditional. The syntax is as for
1531 breakpoints; either an "if" clause appended to the "trace" command,
1532 or the "condition" command is available. GDB sends the condition to
1533 the target for evaluation using the same bytecode format as is used
1534 for tracepoint actions.
1536 * The disassemble command now supports: an optional /r modifier, print the
1537 raw instructions in hex as well as in symbolic form, and an optional /m
1538 modifier to print mixed source+assembly.
1540 * Process record and replay
1542 In a architecture environment that supports ``process record and
1543 replay'', ``process record and replay'' target can record a log of
1544 the process execution, and replay it with both forward and reverse
1547 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1548 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1549 set execution-direction {forward|reverse}, for targets that support
1552 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1553 feature is available with a native GDB running on kernel version
1556 * GDB now has support for multi-byte and wide character sets on the
1557 target. Strings whose character type is wchar_t, char16_t, or
1558 char32_t are now correctly printed. GDB supports wide- and unicode-
1559 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1560 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1561 `printf'. This feature requires iconv to work properly; if your
1562 system does not have a working iconv, GDB can use GNU libiconv. See
1563 the installation instructions for more information.
1565 * GDB now supports automatic retrieval of shared library files from
1566 remote targets. To use this feature, specify a system root that begins
1567 with the `remote:' prefix, either via the `set sysroot' command or via
1568 the `--with-sysroot' configure-time option.
1570 * "info sharedlibrary" now takes an optional regex of libraries to show,
1571 and it now reports if a shared library has no debugging information.
1573 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1574 now complete on file names.
1576 * When completing in expressions, gdb will attempt to limit
1577 completions to allowable structure or union fields, where appropriate.
1578 For instance, consider:
1580 # struct example { int f1; double f2; };
1581 # struct example variable;
1584 If the user types TAB at the end of this command line, the available
1585 completions will be "f1" and "f2".
1587 * Inlined functions are now supported. They show up in backtraces, and
1588 the "step", "next", and "finish" commands handle them automatically.
1590 * GDB now supports the token-splicing (##) and stringification (#)
1591 operators when expanding macros. It also supports variable-arity
1594 * GDB now supports inspecting extra signal information, exported by
1595 the new $_siginfo convenience variable. The feature is currently
1596 implemented on linux ARM, i386 and amd64.
1598 * GDB can now display the VFP floating point registers and NEON vector
1599 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1600 can provide these registers (requires Linux 2.6.30 or later). Remote
1601 and simulator targets may also provide them.
1603 * New remote packets
1606 Search memory for a sequence of bytes.
1609 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1610 operation over reliable transport links. Use of this packet is
1611 controlled by the `set remote noack-packet' command.
1614 Kill the process with the specified process ID. Use this in preference
1615 to `k' when multiprocess protocol extensions are supported.
1618 Obtains additional operating system information
1622 Read or write additional signal information.
1624 * Removed remote protocol undocumented extension
1626 An undocumented extension to the remote protocol's `S' stop reply
1627 packet that permited the stub to pass a process id was removed.
1628 Remote servers should use the `T' stop reply packet instead.
1630 * GDB now supports multiple function calling conventions according to the
1631 DWARF-2 DW_AT_calling_convention function attribute.
1633 * The SH target utilizes the aforementioned change to distinguish between gcc
1634 and Renesas calling convention. It also adds the new CLI commands
1635 `set/show sh calling-convention'.
1637 * GDB can now read compressed debug sections, as produced by GNU gold
1638 with the --compress-debug-sections=zlib flag.
1640 * 64-bit core files are now supported on AIX.
1642 * Thread switching is now supported on Tru64.
1644 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1645 which will be allocated using malloc later in program execution.
1647 * The qXfer:libraries:read remote procotol packet now allows passing a
1648 list of section offsets.
1650 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1651 conditions handling signals delivered during attach or thread creation
1652 have also been fixed.
1654 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1655 From the user's standpoint, all unqualified instances of True and False
1656 are treated as the standard definitions, regardless of context.
1658 * GDB now parses C++ symbol and type names more flexibly. For
1661 template<typename T> class C { };
1664 GDB will now correctly handle all of:
1666 ptype C<char const *>
1667 ptype C<char const*>
1668 ptype C<const char *>
1669 ptype C<const char*>
1671 * New features in the GDB remote stub, gdbserver
1673 - The "--wrapper" command-line argument tells gdbserver to use a
1674 wrapper program to launch programs for debugging.
1676 - On PowerPC and S/390 targets, it is now possible to use a single
1677 gdbserver executable to debug both 32-bit and 64-bit programs.
1678 (This requires gdbserver itself to be built as a 64-bit executable.)
1680 - gdbserver uses the new noack protocol mode for TCP connections to
1681 reduce communications latency, if also supported and enabled in GDB.
1683 - Support for the sparc64-linux-gnu target is now included in
1686 - The amd64-linux build of gdbserver now supports debugging both
1687 32-bit and 64-bit programs.
1689 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1690 now support hardware watchpoints, and will use them automatically
1695 GDB now has support for scripting using Python. Whether this is
1696 available is determined at configure time.
1698 New GDB commands can now be written in Python.
1700 * Ada tasking support
1702 Ada tasks can now be inspected in GDB. The following commands have
1706 Print the list of Ada tasks.
1708 Print detailed information about task number N.
1710 Print the task number of the current task.
1712 Switch the context of debugging to task number N.
1714 * Support for user-defined prefixed commands. The "define" command can
1715 add new commands to existing prefixes, e.g. "target".
1717 * Multi-inferior, multi-process debugging.
1719 GDB now has generalized support for multi-inferior debugging. See
1720 "Debugging Multiple Inferiors" in the manual for more information.
1721 Although availability still depends on target support, the command
1722 set is more uniform now. The GNU/Linux specific multi-forks support
1723 has been migrated to this new framework. This implied some user
1724 visible changes; see "New commands" and also "Removed commands"
1727 * Target descriptions can now describe the target OS ABI. See the
1728 "Target Description Format" section in the user manual for more
1731 * Target descriptions can now describe "compatible" architectures
1732 to indicate that the target can execute applications for a different
1733 architecture in addition to those for the main target architecture.
1734 See the "Target Description Format" section in the user manual for
1737 * Multi-architecture debugging.
1739 GDB now includes general supports for debugging applications on
1740 hybrid systems that use more than one single processor architecture
1741 at the same time. Each such hybrid architecture still requires
1742 specific support to be added. The only hybrid architecture supported
1743 in this version of GDB is the Cell Broadband Engine.
1745 * GDB now supports integrated debugging of Cell/B.E. applications that
1746 use both the PPU and SPU architectures. To enable support for hybrid
1747 Cell/B.E. debugging, you need to configure GDB to support both the
1748 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1749 --enable-targets configure option.
1751 * Non-stop mode debugging.
1753 For some targets, GDB now supports an optional mode of operation in
1754 which you can examine stopped threads while other threads continue
1755 to execute freely. This is referred to as non-stop mode, with the
1756 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1757 section in the user manual for more information.
1759 To be able to support remote non-stop debugging, a remote stub needs
1760 to implement the non-stop mode remote protocol extensions, as
1761 described in the "Remote Non-Stop" section of the user manual. The
1762 GDB remote stub, gdbserver, has been adjusted to support these
1763 extensions on linux targets.
1765 * New commands (for set/show, see "New options" below)
1767 catch syscall [NAME(S) | NUMBER(S)]
1768 Catch system calls. Arguments, which should be names of system
1769 calls or their numbers, mean catch only those syscalls. Without
1770 arguments, every syscall will be caught. When the inferior issues
1771 any of the specified syscalls, GDB will stop and announce the system
1772 call, both when it is called and when its call returns. This
1773 feature is currently available with a native GDB running on the
1774 Linux Kernel, under the following architectures: x86, x86_64,
1775 PowerPC and PowerPC64.
1777 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1779 Search memory for a sequence of bytes.
1781 maint set python print-stack
1782 maint show python print-stack
1783 Show a stack trace when an error is encountered in a Python script.
1786 Invoke CODE by passing it to the Python interpreter.
1791 These allow macros to be defined, undefined, and listed
1795 Show operating system information about processes.
1798 List the inferiors currently under GDB's control.
1801 Switch focus to inferior number NUM.
1804 Detach from inferior number NUM.
1807 Kill inferior number NUM.
1811 set spu stop-on-load
1812 show spu stop-on-load
1813 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1815 set spu auto-flush-cache
1816 show spu auto-flush-cache
1817 Control whether to automatically flush the software-managed cache
1818 during Cell/B.E. debugging.
1820 set sh calling-convention
1821 show sh calling-convention
1822 Control the calling convention used when calling SH target functions.
1825 show debug timestamp
1826 Control display of timestamps with GDB debugging output.
1828 set disassemble-next-line
1829 show disassemble-next-line
1830 Control display of disassembled source lines or instructions when
1833 set remote noack-packet
1834 show remote noack-packet
1835 Set/show the use of remote protocol QStartNoAckMode packet. See above
1836 under "New remote packets."
1838 set remote query-attached-packet
1839 show remote query-attached-packet
1840 Control use of remote protocol `qAttached' (query-attached) packet.
1842 set remote read-siginfo-object
1843 show remote read-siginfo-object
1844 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1847 set remote write-siginfo-object
1848 show remote write-siginfo-object
1849 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1852 set remote reverse-continue
1853 show remote reverse-continue
1854 Control use of remote protocol 'bc' (reverse-continue) packet.
1856 set remote reverse-step
1857 show remote reverse-step
1858 Control use of remote protocol 'bs' (reverse-step) packet.
1860 set displaced-stepping
1861 show displaced-stepping
1862 Control displaced stepping mode. Displaced stepping is a way to
1863 single-step over breakpoints without removing them from the debuggee.
1864 Also known as "out-of-line single-stepping".
1867 show debug displaced
1868 Control display of debugging info for displaced stepping.
1870 maint set internal-error
1871 maint show internal-error
1872 Control what GDB does when an internal error is detected.
1874 maint set internal-warning
1875 maint show internal-warning
1876 Control what GDB does when an internal warning is detected.
1881 Use a wrapper program to launch programs for debugging.
1883 set multiple-symbols (all|ask|cancel)
1884 show multiple-symbols
1885 The value of this variable can be changed to adjust the debugger behavior
1886 when an expression or a breakpoint location contains an ambiguous symbol
1887 name (an overloaded function name, for instance).
1889 set breakpoint always-inserted
1890 show breakpoint always-inserted
1891 Keep breakpoints always inserted in the target, as opposed to inserting
1892 them when resuming the target, and removing them when the target stops.
1893 This option can improve debugger performance on slow remote targets.
1895 set arm fallback-mode (arm|thumb|auto)
1896 show arm fallback-mode
1897 set arm force-mode (arm|thumb|auto)
1899 These commands control how ARM GDB determines whether instructions
1900 are ARM or Thumb. The default for both settings is auto, which uses
1901 the current CPSR value for instructions without symbols; previous
1902 versions of GDB behaved as if "set arm fallback-mode arm".
1904 set disable-randomization
1905 show disable-randomization
1906 Standalone programs run with the virtual address space randomization enabled
1907 by default on some platforms. This option keeps the addresses stable across
1908 multiple debugging sessions.
1912 Control whether other threads are stopped or not when some thread hits
1917 Requests that asynchronous execution is enabled in the target, if available.
1918 In this case, it's possible to resume target in the background, and interact
1919 with GDB while the target is running. "show target-async" displays the
1920 current state of asynchronous execution of the target.
1922 set target-wide-charset
1923 show target-wide-charset
1924 The target-wide-charset is the name of the character set that GDB
1925 uses when printing characters whose type is wchar_t.
1927 set tcp auto-retry (on|off)
1929 set tcp connect-timeout
1930 show tcp connect-timeout
1931 These commands allow GDB to retry failed TCP connections to a remote stub
1932 with a specified timeout period; this is useful if the stub is launched
1933 in parallel with GDB but may not be ready to accept connections immediately.
1935 set libthread-db-search-path
1936 show libthread-db-search-path
1937 Control list of directories which GDB will search for appropriate
1940 set schedule-multiple (on|off)
1941 show schedule-multiple
1942 Allow GDB to resume all threads of all processes or only threads of
1943 the current process.
1947 Use more aggressive caching for accesses to the stack. This improves
1948 performance of remote debugging (particularly backtraces) without
1949 affecting correctness.
1951 set interactive-mode (on|off|auto)
1952 show interactive-mode
1953 Control whether GDB runs in interactive mode (on) or not (off).
1954 When in interactive mode, GDB waits for the user to answer all
1955 queries. Otherwise, GDB does not wait and assumes the default
1956 answer. When set to auto (the default), GDB determines which
1957 mode to use based on the stdin settings.
1962 For program forks, this is replaced by the new more generic `info
1963 inferiors' command. To list checkpoints, you can still use the
1964 `info checkpoints' command, which was an alias for the `info forks'
1968 Replaced by the new `inferior' command. To switch between
1969 checkpoints, you can still use the `restart' command, which was an
1970 alias for the `fork' command.
1973 This is removed, since some targets don't have a notion of
1974 processes. To switch between processes, you can still use the
1975 `inferior' command using GDB's own inferior number.
1978 For program forks, this is replaced by the new more generic `kill
1979 inferior' command. To delete a checkpoint, you can still use the
1980 `delete checkpoint' command, which was an alias for the `delete
1984 For program forks, this is replaced by the new more generic `detach
1985 inferior' command. To detach a checkpoint, you can still use the
1986 `detach checkpoint' command, which was an alias for the `detach
1989 * New native configurations
1991 x86/x86_64 Darwin i[34567]86-*-darwin*
1993 x86_64 MinGW x86_64-*-mingw*
1997 Lattice Mico32 lm32-*
1998 x86 DICOS i[34567]86-*-dicos*
1999 x86_64 DICOS x86_64-*-dicos*
2002 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2003 (mingw32ce) debugging.
2009 These commands were actually not implemented on any target.
2011 *** Changes in GDB 6.8
2013 * New native configurations
2015 NetBSD/hppa hppa*-*netbsd*
2016 Xtensa GNU/Linux xtensa*-*-linux*
2020 NetBSD/hppa hppa*-*-netbsd*
2021 Xtensa GNU/Lunux xtensa*-*-linux*
2023 * Change in command line behavior -- corefiles vs. process ids.
2025 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2026 attaching to process NUMBER fails, GDB no longer attempts to open a
2027 core file named NUMBER. Attaching to a program using the -c option
2028 is no longer supported. Instead, use the '-p' or '--pid' options.
2030 * GDB can now be built as a native debugger for debugging Windows x86
2031 (mingw32) Portable Executable (PE) programs.
2033 * Pending breakpoints no longer change their number when their address
2036 * GDB now supports breakpoints with multiple locations,
2037 including breakpoints on C++ constructors, inside C++ templates,
2038 and in inlined functions.
2040 * GDB's ability to debug optimized code has been improved. GDB more
2041 accurately identifies function bodies and lexical blocks that occupy
2042 more than one contiguous range of addresses.
2044 * Target descriptions can now describe registers for PowerPC.
2046 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2047 registers on PowerPC targets.
2049 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2050 targets even when the libthread_db library is not available.
2052 * The GDB remote stub, gdbserver, now supports the new file transfer
2053 commands (remote put, remote get, and remote delete).
2055 * The GDB remote stub, gdbserver, now supports run and attach in
2056 extended-remote mode.
2058 * hppa*64*-*-hpux11* target broken
2059 The debugger is unable to start a program and fails with the following
2060 error: "Error trying to get information about dynamic linker".
2061 The gdb-6.7 release is also affected.
2063 * GDB now supports the --enable-targets= configure option to allow
2064 building a single GDB executable that supports multiple remote
2065 target architectures.
2067 * GDB now supports debugging C and C++ programs which use the
2068 Decimal Floating Point extension. In addition, the PowerPC target
2069 now has a set of pseudo-registers to inspect decimal float values
2070 stored in two consecutive float registers.
2072 * The -break-insert MI command can optionally create pending
2075 * Improved support for debugging Ada
2076 Many improvements to the Ada language support have been made. These
2078 - Better support for Ada2005 interface types
2079 - Improved handling of arrays and slices in general
2080 - Better support for Taft-amendment types
2081 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2083 - Improved command completion in Ada
2086 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2091 set print frame-arguments (all|scalars|none)
2092 show print frame-arguments
2093 The value of this variable can be changed to control which argument
2094 values should be printed by the debugger when displaying a frame.
2099 Transfer files to and from a remote target, and delete remote files.
2106 Transfer files to and from a remote target, and delete remote files.
2108 * New remote packets
2115 Open, close, read, write, and delete files on the remote system.
2118 Attach to an existing process on the remote system, in extended-remote
2122 Run a new process on the remote system, in extended-remote mode.
2124 *** Changes in GDB 6.7
2126 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2127 bfd, libiberty and opcodes, as revealed by static analysis donated by
2128 Coverity, Inc. (http://scan.coverity.com).
2130 * When looking up multiply-defined global symbols, GDB will now prefer the
2131 symbol definition in the current shared library if it was built using the
2132 -Bsymbolic linker option.
2134 * When the Text User Interface (TUI) is not configured, GDB will now
2135 recognize the -tui command-line option and print a message that the TUI
2138 * The GDB remote stub, gdbserver, now has lower overhead for high
2139 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2141 * GDB for MIPS targets now autodetects whether a remote target provides
2142 32-bit or 64-bit register values.
2144 * Support for C++ member pointers has been improved.
2146 * GDB now understands XML target descriptions, which specify the
2147 target's overall architecture. GDB can read a description from
2148 a local file or over the remote serial protocol.
2150 * Vectors of single-byte data use a new integer type which is not
2151 automatically displayed as character or string data.
2153 * The /s format now works with the print command. It displays
2154 arrays of single-byte integers and pointers to single-byte integers
2157 * Target descriptions can now describe target-specific registers,
2158 for architectures which have implemented the support (currently
2159 only ARM, M68K, and MIPS).
2161 * GDB and the GDB remote stub, gdbserver, now support the XScale
2164 * The GDB remote stub, gdbserver, has been updated to support
2165 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2166 has been rewritten to use the standard GDB remote protocol.
2168 * GDB can now step into C++ functions which are called through thunks.
2170 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2172 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2173 layout. It also supports a TextSeg= and DataSeg= response when only
2174 segment base addresses (rather than offsets) are available.
2176 * The /i format now outputs any trailing branch delay slot instructions
2177 immediately following the last instruction within the count specified.
2179 * The GDB remote protocol "T" stop reply packet now supports a
2180 "library" response. Combined with the new "qXfer:libraries:read"
2181 packet, this response allows GDB to debug shared libraries on targets
2182 where the operating system manages the list of loaded libraries (e.g.
2183 Windows and SymbianOS).
2185 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2186 (DLLs) on Windows and Windows CE targets.
2188 * GDB now supports a faster verification that a .debug file matches its binary
2189 according to its build-id signature, if the signature is present.
2195 Enable or disable hardware flow control (RTS/CTS) on the serial port
2196 when debugging using remote targets.
2198 set mem inaccessible-by-default
2199 show mem inaccessible-by-default
2200 If the target supplies a memory map, for instance via the remote
2201 protocol's "qXfer:memory-map:read" packet, setting this variable
2202 prevents GDB from accessing memory outside the memory map. This
2203 is useful for targets with memory mapped registers or which react
2204 badly to accesses of unmapped address space.
2206 set breakpoint auto-hw
2207 show breakpoint auto-hw
2208 If the target supplies a memory map, for instance via the remote
2209 protocol's "qXfer:memory-map:read" packet, setting this variable
2210 lets GDB use hardware breakpoints automatically for memory regions
2211 where it can not use software breakpoints. This covers both the
2212 "break" command and internal breakpoints used for other commands
2213 including "next" and "finish".
2216 catch exception unhandled
2217 Stop the program execution when Ada exceptions are raised.
2220 Stop the program execution when an Ada assertion failed.
2224 Set an alternate system root for target files. This is a more
2225 general version of "set solib-absolute-prefix", which is now
2226 an alias to "set sysroot".
2229 Provide extended SPU facility status information. This set of
2230 commands is available only when debugging the Cell/B.E. SPU
2233 * New native configurations
2235 OpenBSD/sh sh*-*openbsd*
2238 unset tdesc filename
2240 Use the specified local file as an XML target description, and do
2241 not query the target for its built-in description.
2245 OpenBSD/sh sh*-*-openbsd*
2246 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2247 Toshiba Media Processor mep-elf
2249 * New remote packets
2252 Ignore the specified signals; pass them directly to the debugged program
2253 without stopping other threads or reporting them to GDB.
2255 qXfer:features:read:
2256 Read an XML target description from the target, which describes its
2261 Read or write contents of an spufs file on the target system. These
2262 packets are available only on the Cell/B.E. SPU architecture.
2264 qXfer:libraries:read:
2265 Report the loaded shared libraries. Combined with new "T" packet
2266 response, this packet allows GDB to debug shared libraries on
2267 targets where the operating system manages the list of loaded
2268 libraries (e.g. Windows and SymbianOS).
2272 Support for these obsolete configurations has been removed.
2280 i[34567]86-*-lynxos*
2281 i[34567]86-*-netware*
2282 i[34567]86-*-sco3.2v5*
2283 i[34567]86-*-sco3.2v4*
2285 i[34567]86-*-sysv4.2*
2288 i[34567]86-*-unixware2*
2289 i[34567]86-*-unixware*
2298 * Other removed features
2305 Various m68k-only ROM monitors.
2312 Various Renesas ROM monitors and debugging interfaces for SH and
2317 Support for a Macraigor serial interface to on-chip debugging.
2318 GDB does not directly support the newer parallel or USB
2323 A debug information format. The predecessor to DWARF 2 and
2324 DWARF 3, which are still supported.
2326 Support for the HP aCC compiler on HP-UX/PA-RISC
2328 SOM-encapsulated symbolic debugging information, automatic
2329 invocation of pxdb, and the aCC custom C++ ABI. This does not
2330 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2331 with aCC can still be debugged on an assembly level.
2333 MIPS ".pdr" sections
2335 A MIPS-specific format used to describe stack frame layout
2336 in debugging information.
2340 GDB could work with an older version of Guile to debug
2341 the interpreter and Scheme programs running in it.
2343 set mips stack-arg-size
2344 set mips saved-gpreg-size
2346 Use "set mips abi" to control parameter passing for MIPS.
2348 *** Changes in GDB 6.6
2353 Cell Broadband Engine SPU spu-elf
2355 * GDB can now be configured as a cross-debugger targeting native Windows
2356 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2357 running on a Windows system over TCP/IP to debug Windows programs.
2359 * The GDB remote stub, gdbserver, has been updated to support Windows and
2360 Cygwin debugging. Both single-threaded and multi-threaded programs are
2363 * The "set trust-readonly-sections" command works again. This command was
2364 broken in GDB 6.3, 6.4, and 6.5.
2366 * The "load" command now supports writing to flash memory, if the remote
2367 stub provides the required support.
2369 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2370 longer requires symbolic debug information (e.g. DWARF-2).
2375 unset substitute-path
2376 show substitute-path
2377 Manage a list of substitution rules that GDB uses to rewrite the name
2378 of the directories where the sources are located. This can be useful
2379 for instance when the sources were moved to a different location
2380 between compilation and debugging.
2384 Print each CLI command as it is executed. Each command is prefixed with
2385 a number of `+' symbols representing the nesting depth.
2386 The source command now has a `-v' option to enable the same feature.
2390 The ARM Demon monitor support (RDP protocol, "target rdp").
2392 Kernel Object Display, an embedded debugging feature which only worked with
2393 an obsolete version of Cisco IOS.
2395 The 'set download-write-size' and 'show download-write-size' commands.
2397 * New remote packets
2400 Tell a stub about GDB client features, and request remote target features.
2401 The first feature implemented is PacketSize, which allows the target to
2402 specify the size of packets it can handle - to minimize the number of
2403 packets required and improve performance when connected to a remote
2407 Fetch an OS auxilliary vector from the remote stub. This packet is a
2408 more efficient replacement for qPart:auxv:read.
2410 qXfer:memory-map:read:
2411 Fetch a memory map from the remote stub, including information about
2412 RAM, ROM, and flash memory devices.
2417 Erase and program a flash memory device.
2419 * Removed remote packets
2422 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2423 used it, and only gdbserver implemented it.
2425 *** Changes in GDB 6.5
2429 Renesas M32C/M16C m32c-elf
2431 Morpho Technologies ms1 ms1-elf
2435 init-if-undefined Initialize a convenience variable, but
2436 only if it doesn't already have a value.
2438 The following commands are presently only implemented for native GNU/Linux:
2440 checkpoint Save a snapshot of the program state.
2442 restart <n> Return the program state to a
2443 previously saved state.
2445 info checkpoints List currently saved checkpoints.
2447 delete-checkpoint <n> Delete a previously saved checkpoint.
2449 set|show detach-on-fork Tell gdb whether to detach from a newly
2450 forked process, or to keep debugging it.
2452 info forks List forks of the user program that
2453 are available to be debugged.
2455 fork <n> Switch to debugging one of several
2456 forks of the user program that are
2457 available to be debugged.
2459 delete-fork <n> Delete a fork from the list of forks
2460 that are available to be debugged (and
2461 kill the forked process).
2463 detach-fork <n> Delete a fork from the list of forks
2464 that are available to be debugged (and
2465 allow the process to continue).
2469 Morpho Technologies ms2 ms1-elf
2471 * Improved Windows host support
2473 GDB now builds as a cross debugger hosted on i686-mingw32, including
2474 native console support, and remote communications using either
2475 network sockets or serial ports.
2477 * Improved Modula-2 language support
2479 GDB can now print most types in the Modula-2 syntax. This includes:
2480 basic types, set types, record types, enumerated types, range types,
2481 pointer types and ARRAY types. Procedure var parameters are correctly
2482 printed and hexadecimal addresses and character constants are also
2483 written in the Modula-2 syntax. Best results can be obtained by using
2484 GNU Modula-2 together with the -gdwarf-2 command line option.
2488 The ARM rdi-share module.
2490 The Netware NLM debug server.
2492 *** Changes in GDB 6.4
2494 * New native configurations
2496 OpenBSD/arm arm*-*-openbsd*
2497 OpenBSD/mips64 mips64-*-openbsd*
2501 Morpho Technologies ms1 ms1-elf
2503 * New command line options
2505 --batch-silent As for --batch, but totally silent.
2506 --return-child-result The debugger will exist with the same value
2507 the child (debugged) program exited with.
2508 --eval-command COMMAND, -ex COMMAND
2509 Execute a single GDB CLI command. This may be
2510 specified multiple times and in conjunction
2511 with the --command (-x) option.
2513 * Deprecated commands removed
2515 The following commands, that were deprecated in 2000, have been
2519 set|show arm disassembly-flavor set|show arm disassembler
2520 othernames set arm disassembler
2521 set|show remotedebug set|show debug remote
2522 set|show archdebug set|show debug arch
2523 set|show eventdebug set|show debug event
2526 * New BSD user-level threads support
2528 It is now possible to debug programs using the user-level threads
2529 library on OpenBSD and FreeBSD. Currently supported (target)
2532 FreeBSD/amd64 x86_64-*-freebsd*
2533 FreeBSD/i386 i386-*-freebsd*
2534 OpenBSD/i386 i386-*-openbsd*
2536 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2537 are not yet supported.
2539 * New support for Matsushita MN10300 w/sim added
2540 (Work in progress). mn10300-elf.
2542 * REMOVED configurations and files
2544 VxWorks and the XDR protocol *-*-vxworks
2545 Motorola MCORE mcore-*-*
2546 National Semiconductor NS32000 ns32k-*-*
2548 * New "set print array-indexes" command
2550 After turning this setting "on", GDB prints the index of each element
2551 when displaying arrays. The default is "off" to preserve the previous
2554 * VAX floating point support
2556 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2558 * User-defined command support
2560 In addition to using $arg0..$arg9 for argument passing, it is now possible
2561 to use $argc to determine now many arguments have been passed. See the
2562 section on user-defined commands in the user manual for more information.
2564 *** Changes in GDB 6.3:
2566 * New command line option
2568 GDB now accepts -l followed by a number to set the timeout for remote
2571 * GDB works with GCC -feliminate-dwarf2-dups
2573 GDB now supports a more compact representation of DWARF-2 debug
2574 information using DW_FORM_ref_addr references. These are produced
2575 by GCC with the option -feliminate-dwarf2-dups and also by some
2576 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2577 to use -feliminate-dwarf2-dups.
2579 * Internationalization
2581 When supported by the host system, GDB will be built with
2582 internationalization (libintl). The task of marking up the sources is
2583 continued, we're looking forward to our first translation.
2587 Initial support for debugging programs compiled with the GNAT
2588 implementation of the Ada programming language has been integrated
2589 into GDB. In this release, support is limited to expression evaluation.
2591 * New native configurations
2593 GNU/Linux/m32r m32r-*-linux-gnu
2597 GDB's remote protocol now includes support for the 'p' packet. This
2598 packet is used to fetch individual registers from a remote inferior.
2600 * END-OF-LIFE registers[] compatibility module
2602 GDB's internal register infrastructure has been completely rewritten.
2603 The new infrastructure making possible the implementation of key new
2604 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2607 GDB 6.3 will be the last release to include the the registers[]
2608 compatibility module that allowed out-of-date configurations to
2609 continue to work. This change directly impacts the following
2619 powerpc bdm protocol
2621 Unless there is activity to revive these configurations, they will be
2622 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2624 * OBSOLETE configurations and files
2626 Configurations that have been declared obsolete in this release have
2627 been commented out. Unless there is activity to revive these
2628 configurations, the next release of GDB will have their sources
2629 permanently REMOVED.
2638 *** Changes in GDB 6.2.1:
2640 * MIPS `break main; run' gave an heuristic-fence-post warning
2642 When attempting to run even a simple program, a warning about
2643 heuristic-fence-post being hit would be reported. This problem has
2646 * MIPS IRIX 'long double' crashed GDB
2648 When examining a long double variable, GDB would get a segmentation
2649 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2650 IRIX long double values).
2654 A bug in the VAX stack code was causing problems with the "next"
2655 command. This problem has been fixed.
2657 *** Changes in GDB 6.2:
2659 * Fix for ``many threads''
2661 On GNU/Linux systems that use the NPTL threads library, a program
2662 rapidly creating and deleting threads would confuse GDB leading to the
2665 ptrace: No such process.
2666 thread_db_get_info: cannot get thread info: generic error
2668 This problem has been fixed.
2670 * "-async" and "-noasync" options removed.
2672 Support for the broken "-noasync" option has been removed (it caused
2675 * New ``start'' command.
2677 This command runs the program until the begining of the main procedure.
2679 * New BSD Kernel Data Access Library (libkvm) interface
2681 Using ``target kvm'' it is now possible to debug kernel core dumps and
2682 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2683 platforms. Currently supported (native-only) configurations are:
2685 FreeBSD/amd64 x86_64-*-freebsd*
2686 FreeBSD/i386 i?86-*-freebsd*
2687 NetBSD/i386 i?86-*-netbsd*
2688 NetBSD/m68k m68*-*-netbsd*
2689 NetBSD/sparc sparc-*-netbsd*
2690 OpenBSD/amd64 x86_64-*-openbsd*
2691 OpenBSD/i386 i?86-*-openbsd*
2692 OpenBSD/m68k m68*-openbsd*
2693 OpenBSD/sparc sparc-*-openbsd*
2695 * Signal trampoline code overhauled
2697 Many generic problems with GDB's signal handling code have been fixed.
2698 These include: backtraces through non-contiguous stacks; recognition
2699 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2700 call; backtrace through a signal trampoline; step into and out of
2701 signal handlers; and single-stepping in the signal trampoline.
2703 Please note that kernel bugs are a limiting factor here. These
2704 features have been shown to work on an s390 GNU/Linux system that
2705 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2707 * Cygwin support for DWARF 2 added.
2709 * New native configurations
2711 GNU/Linux/hppa hppa*-*-linux*
2712 OpenBSD/hppa hppa*-*-openbsd*
2713 OpenBSD/m68k m68*-*-openbsd*
2714 OpenBSD/m88k m88*-*-openbsd*
2715 OpenBSD/powerpc powerpc-*-openbsd*
2716 NetBSD/vax vax-*-netbsd*
2717 OpenBSD/vax vax-*-openbsd*
2719 * END-OF-LIFE frame compatibility module
2721 GDB's internal frame infrastructure has been completely rewritten.
2722 The new infrastructure making it possible to support key new features
2723 including DWARF 2 Call Frame Information. To aid in the task of
2724 migrating old configurations to this new infrastructure, a
2725 compatibility module, that allowed old configurations to continue to
2726 work, was also included.
2728 GDB 6.2 will be the last release to include this frame compatibility
2729 module. This change directly impacts the following configurations:
2739 Unless there is activity to revive these configurations, they will be
2740 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2742 * REMOVED configurations and files
2744 Sun 3, running SunOS 3 m68*-*-sunos3*
2745 Sun 3, running SunOS 4 m68*-*-sunos4*
2746 Sun 2, running SunOS 3 m68000-*-sunos3*
2747 Sun 2, running SunOS 4 m68000-*-sunos4*
2748 Motorola 680x0 running LynxOS m68*-*-lynxos*
2749 AT&T 3b1/Unix pc m68*-att-*
2750 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2751 decstation mips-dec-* mips-little-*
2752 riscos mips-*-riscos* mips-*-sysv*
2753 sonymips mips-sony-*
2754 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2756 *** Changes in GDB 6.1.1:
2758 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2760 The TUI (Text-mode User Interface) is now built as part of a default
2761 GDB configuration. It is enabled by either selecting the TUI with the
2762 command line option "-i=tui" or by running the separate "gdbtui"
2763 program. For more information on the TUI, see the manual "Debugging
2766 * Pending breakpoint support (also included in GDB 6.1)
2768 Support has been added to allow you to specify breakpoints in shared
2769 libraries that have not yet been loaded. If a breakpoint location
2770 cannot be found, and the "breakpoint pending" option is set to auto,
2771 GDB queries you if you wish to make the breakpoint pending on a future
2772 shared-library load. If and when GDB resolves the breakpoint symbol,
2773 the pending breakpoint is removed as one or more regular breakpoints
2776 Pending breakpoints are very useful for GCJ Java debugging.
2778 * Fixed ISO-C build problems
2780 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2781 non ISO-C code that stopped them being built using a more strict ISO-C
2782 compiler (e.g., IBM's C compiler).
2784 * Fixed build problem on IRIX 5
2786 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2787 wasn't able to compile compile on an IRIX 5 system.
2789 * Added execute permission to gdb/gdbserver/configure
2791 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2792 permission. This bug would cause configure to fail on a number of
2793 systems (Solaris, IRIX). Ref: server/519.
2795 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2797 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2798 has been updated to use constant array sizes.
2800 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2802 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2803 its generated DWARF Call Frame Info. This encoding was causing GDB to
2804 panic, that panic has been fixed. Ref: gdb/1628.
2806 * Fixed a problem when examining parameters in shared library code.
2808 When examining parameters in optimized shared library code generated
2809 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2810 not available''. GDB now correctly displays the variable's value.
2812 *** Changes in GDB 6.1:
2814 * Removed --with-mmalloc
2816 Support for the mmalloc memory manager has been removed, as it
2817 conflicted with the internal gdb byte cache.
2819 * Changes in AMD64 configurations
2821 The AMD64 target now includes the %cs and %ss registers. As a result
2822 the AMD64 remote protocol has changed; this affects the floating-point
2823 and SSE registers. If you rely on those registers for your debugging,
2824 you should upgrade gdbserver on the remote side.
2826 * Revised SPARC target
2828 The SPARC target has been completely revised, incorporating the
2829 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2830 support for LynxOS and SunOS 4 has been dropped. Calling functions
2831 from within GDB on operating systems with a non-executable stack
2832 (Solaris, OpenBSD) now works.
2836 GDB has a new C++ demangler which does a better job on the mangled
2837 names generated by current versions of g++. It also runs faster, so
2838 with this and other changes gdb should now start faster on large C++
2841 * DWARF 2 Location Expressions
2843 GDB support for location expressions has been extended to support function
2844 arguments and frame bases. Older versions of GDB could crash when they
2847 * C++ nested types and namespaces
2849 GDB's support for nested types and namespaces in C++ has been
2850 improved, especially if you use the DWARF 2 debugging format. (This
2851 is the default for recent versions of GCC on most platforms.)
2852 Specifically, if you have a class "Inner" defined within a class or
2853 namespace "Outer", then GDB realizes that the class's name is
2854 "Outer::Inner", not simply "Inner". This should greatly reduce the
2855 frequency of complaints about not finding RTTI symbols. In addition,
2856 if you are stopped at inside of a function defined within a namespace,
2857 GDB modifies its name lookup accordingly.
2859 * New native configurations
2861 NetBSD/amd64 x86_64-*-netbsd*
2862 OpenBSD/amd64 x86_64-*-openbsd*
2863 OpenBSD/alpha alpha*-*-openbsd*
2864 OpenBSD/sparc sparc-*-openbsd*
2865 OpenBSD/sparc64 sparc64-*-openbsd*
2867 * New debugging protocols
2869 M32R with SDI protocol m32r-*-elf*
2871 * "set prompt-escape-char" command deleted.
2873 The command "set prompt-escape-char" has been deleted. This command,
2874 and its very obscure effet on GDB's prompt, was never documented,
2875 tested, nor mentioned in the NEWS file.
2877 * OBSOLETE configurations and files
2879 Configurations that have been declared obsolete in this release have
2880 been commented out. Unless there is activity to revive these
2881 configurations, the next release of GDB will have their sources
2882 permanently REMOVED.
2884 Sun 3, running SunOS 3 m68*-*-sunos3*
2885 Sun 3, running SunOS 4 m68*-*-sunos4*
2886 Sun 2, running SunOS 3 m68000-*-sunos3*
2887 Sun 2, running SunOS 4 m68000-*-sunos4*
2888 Motorola 680x0 running LynxOS m68*-*-lynxos*
2889 AT&T 3b1/Unix pc m68*-att-*
2890 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2891 decstation mips-dec-* mips-little-*
2892 riscos mips-*-riscos* mips-*-sysv*
2893 sonymips mips-sony-*
2894 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2896 * REMOVED configurations and files
2898 SGI Irix-4.x mips-sgi-irix4 or iris4
2899 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2900 Z8000 simulator z8k-zilog-none or z8ksim
2901 Matsushita MN10200 w/simulator mn10200-*-*
2902 H8/500 simulator h8500-hitachi-hms or h8500hms
2903 HP/PA running BSD hppa*-*-bsd*
2904 HP/PA running OSF/1 hppa*-*-osf*
2905 HP/PA Pro target hppa*-*-pro*
2906 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2907 386BSD i[3456]86-*-bsd*
2908 Sequent family i[3456]86-sequent-sysv4*
2909 i[3456]86-sequent-sysv*
2910 i[3456]86-sequent-bsd*
2911 SPARC running LynxOS sparc-*-lynxos*
2912 SPARC running SunOS 4 sparc-*-sunos4*
2913 Tsqware Sparclet sparclet-*-*
2914 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2916 *** Changes in GDB 6.0:
2920 Support for debugging the Objective-C programming language has been
2921 integrated into GDB.
2923 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2925 DWARF 2's Call Frame Information makes available compiler generated
2926 information that more exactly describes the program's run-time stack.
2927 By using this information, GDB is able to provide more robust stack
2930 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2931 have been updated to use a new backtrace mechanism which includes
2932 DWARF 2 CFI support.
2936 GDB's remote protocol has been extended to include support for hosted
2937 file I/O (where the remote target uses GDB's file system). See GDB's
2938 remote protocol documentation for details.
2940 * All targets using the new architecture framework.
2942 All of GDB's targets have been updated to use the new internal
2943 architecture framework. The way is now open for future GDB releases
2944 to include cross-architecture native debugging support (i386 on amd64,
2947 * GNU/Linux's Thread Local Storage (TLS)
2949 GDB now includes support for for the GNU/Linux implementation of
2950 per-thread variables.
2952 * GNU/Linux's Native POSIX Thread Library (NPTL)
2954 GDB's thread code has been updated to work with either the new
2955 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2957 * Separate debug info.
2959 GDB, in conjunction with BINUTILS, now supports a mechanism for
2960 automatically loading debug information from a separate file. Instead
2961 of shipping full debug and non-debug versions of system libraries,
2962 system integrators can now instead ship just the stripped libraries
2963 and optional debug files.
2965 * DWARF 2 Location Expressions
2967 DWARF 2 Location Expressions allow the compiler to more completely
2968 describe the location of variables (even in optimized code) to the
2971 GDB now includes preliminary support for location expressions (support
2972 for DW_OP_piece is still missing).
2976 A number of long standing bugs that caused GDB to die while starting a
2977 Java application have been fixed. GDB's Java support is now
2978 considered "useable".
2980 * GNU/Linux support for fork, vfork, and exec.
2982 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2983 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2986 * GDB supports logging output to a file
2988 There are two new commands, "set logging" and "show logging", which can be
2989 used to capture GDB's output to a file.
2991 * The meaning of "detach" has changed for gdbserver
2993 The "detach" command will now resume the application, as documented. To
2994 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2997 * d10v, m68hc11 `regs' command deprecated
2999 The `info registers' command has been updated so that it displays the
3000 registers using a format identical to the old `regs' command.
3004 A new command, "maint set profile on/off", has been added. This command can
3005 be used to enable or disable profiling while running GDB, to profile a
3006 session or a set of commands. In addition there is a new configure switch,
3007 "--enable-profiling", which will cause GDB to be compiled with profiling
3008 data, for more informative profiling results.
3010 * Default MI syntax changed to "mi2".
3012 The default MI (machine interface) syntax, enabled by the command line
3013 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3014 "mi1", can be enabled by specifying the option "-i=mi1".
3016 Support for the original "mi0" syntax (included in GDB 5.0) has been
3019 Fix for gdb/192: removed extraneous space when displaying frame level.
3020 Fix for gdb/672: update changelist is now output in mi list format.
3021 Fix for gdb/702: a -var-assign that updates the value now shows up
3022 in a subsequent -var-update.
3024 * New native configurations.
3026 FreeBSD/amd64 x86_64-*-freebsd*
3028 * Multi-arched targets.
3030 HP/PA HPUX11 hppa*-*-hpux*
3031 Renesas M32R/D w/simulator m32r-*-elf*
3033 * OBSOLETE configurations and files
3035 Configurations that have been declared obsolete in this release have
3036 been commented out. Unless there is activity to revive these
3037 configurations, the next release of GDB will have their sources
3038 permanently REMOVED.
3040 Z8000 simulator z8k-zilog-none or z8ksim
3041 Matsushita MN10200 w/simulator mn10200-*-*
3042 H8/500 simulator h8500-hitachi-hms or h8500hms
3043 HP/PA running BSD hppa*-*-bsd*
3044 HP/PA running OSF/1 hppa*-*-osf*
3045 HP/PA Pro target hppa*-*-pro*
3046 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3047 Sequent family i[3456]86-sequent-sysv4*
3048 i[3456]86-sequent-sysv*
3049 i[3456]86-sequent-bsd*
3050 Tsqware Sparclet sparclet-*-*
3051 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3053 * REMOVED configurations and files
3056 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3057 IBM AIX PS/2 i[3456]86-*-aix
3058 i386 running Mach 3.0 i[3456]86-*-mach3*
3059 i386 running Mach i[3456]86-*-mach*
3060 i386 running OSF/1 i[3456]86-*osf1mk*
3061 HP/Apollo 68k Family m68*-apollo*-sysv*,
3063 m68*-hp-bsd*, m68*-hp-hpux*
3064 Argonaut Risc Chip (ARC) arc-*-*
3065 Mitsubishi D30V d30v-*-*
3066 Fujitsu FR30 fr30-*-elf*
3067 OS/9000 i[34]86-*-os9k
3068 I960 with MON960 i960-*-coff
3070 * MIPS $fp behavior changed
3072 The convenience variable $fp, for the MIPS, now consistently returns
3073 the address of the current frame's base. Previously, depending on the
3074 context, $fp could refer to either $sp or the current frame's base
3075 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3076 The GNU Source-Level Debugger''.
3078 *** Changes in GDB 5.3:
3080 * GNU/Linux shared library multi-threaded performance improved.
3082 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3083 `/proc', in preference to `ptrace' for memory reads. This may result
3084 in an improvement in the start-up time of multi-threaded, shared
3085 library applications when run under GDB. One GDB user writes: ``loads
3086 shared libs like mad''.
3088 * ``gdbserver'' now supports multi-threaded applications on some targets
3090 Support for debugging multi-threaded applications which use
3091 the GNU/Linux LinuxThreads package has been added for
3092 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3093 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3095 * GDB now supports C/C++ preprocessor macros.
3097 GDB now expands preprocessor macro invocations in C/C++ expressions,
3098 and provides various commands for showing macro definitions and how
3101 The new command `macro expand EXPRESSION' expands any macro
3102 invocations in expression, and shows the result.
3104 The new command `show macro MACRO-NAME' shows the definition of the
3105 macro named MACRO-NAME, and where it was defined.
3107 Most compilers don't include information about macros in the debugging
3108 information by default. In GCC 3.1, for example, you need to compile
3109 your program with the options `-gdwarf-2 -g3'. If the macro
3110 information is present in the executable, GDB will read it.
3112 * Multi-arched targets.
3114 DEC Alpha (partial) alpha*-*-*
3115 DEC VAX (partial) vax-*-*
3117 National Semiconductor NS32000 (partial) ns32k-*-*
3118 Motorola 68000 (partial) m68k-*-*
3119 Motorola MCORE mcore-*-*
3123 Fujitsu FRV architecture added by Red Hat frv*-*-*
3126 * New native configurations
3128 Alpha NetBSD alpha*-*-netbsd*
3129 SH NetBSD sh*-*-netbsdelf*
3130 MIPS NetBSD mips*-*-netbsd*
3131 UltraSPARC NetBSD sparc64-*-netbsd*
3133 * OBSOLETE configurations and files
3135 Configurations that have been declared obsolete in this release have
3136 been commented out. Unless there is activity to revive these
3137 configurations, the next release of GDB will have their sources
3138 permanently REMOVED.
3140 Mitsubishi D30V d30v-*-*
3141 OS/9000 i[34]86-*-os9k
3142 IBM AIX PS/2 i[3456]86-*-aix
3143 Fujitsu FR30 fr30-*-elf*
3144 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3145 Argonaut Risc Chip (ARC) arc-*-*
3146 i386 running Mach 3.0 i[3456]86-*-mach3*
3147 i386 running Mach i[3456]86-*-mach*
3148 i386 running OSF/1 i[3456]86-*osf1mk*
3149 HP/Apollo 68k Family m68*-apollo*-sysv*,
3151 m68*-hp-bsd*, m68*-hp-hpux*
3152 I960 with MON960 i960-*-coff
3154 * OBSOLETE languages
3156 CHILL, a Pascal like language used by telecommunications companies.
3158 * REMOVED configurations and files
3160 AMD 29k family via UDI a29k-amd-udi, udi29k
3161 A29K VxWorks a29k-*-vxworks
3162 AMD 29000 embedded, using EBMON a29k-none-none
3163 AMD 29000 embedded with COFF a29k-none-coff
3164 AMD 29000 embedded with a.out a29k-none-aout
3166 testsuite/gdb.hp/gdb.threads-hp/ directory
3168 * New command "set max-user-call-depth <nnn>"
3170 This command allows the user to limit the call depth of user-defined
3171 commands. The default is 1024.
3173 * Changes in FreeBSD/i386 native debugging.
3175 Support for the "generate-core-file" has been added.
3177 * New commands "dump", "append", and "restore".
3179 These commands allow data to be copied from target memory
3180 to a bfd-format or binary file (dump and append), and back
3181 from a file into memory (restore).
3183 * Improved "next/step" support on multi-processor Alpha Tru64.
3185 The previous single-step mechanism could cause unpredictable problems,
3186 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3187 of a software single-step mechanism prevents this.
3189 *** Changes in GDB 5.2.1:
3197 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3198 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3199 Fix, by Joel Brobecker imported from mainline.
3201 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3202 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3203 Fix, by Fred Fish, imported from mainline.
3205 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3206 Surprisingly enough, it works now.
3207 By Michal Ludvig, imported from mainline.
3209 i386 hardware watchpoint support:
3210 avoid misses on second run for some targets.
3211 By Pierre Muller, imported from mainline.
3213 *** Changes in GDB 5.2:
3215 * New command "set trust-readonly-sections on[off]".
3217 This command is a hint that tells gdb that read-only sections
3218 really are read-only (ie. that their contents will not change).
3219 In this mode, gdb will go to the object file rather than the
3220 target to read memory from read-only sections (such as ".text").
3221 This can be a significant performance improvement on some
3222 (notably embedded) targets.
3224 * New command "generate-core-file" (or "gcore").
3226 This new gdb command allows the user to drop a core file of the child
3227 process state at any time. So far it's been implemented only for
3228 GNU/Linux and Solaris, but should be relatively easily ported to other
3229 hosts. Argument is core file name (defaults to core.<pid>).
3231 * New command line option
3233 GDB now accepts --pid or -p followed by a process id.
3235 * Change in command line behavior -- corefiles vs. process ids.
3237 There is a subtle behavior in the way in which GDB handles
3238 command line arguments. The first non-flag argument is always
3239 a program to debug, but the second non-flag argument may either
3240 be a corefile or a process id. Previously, GDB would attempt to
3241 open the second argument as a corefile, and if that failed, would
3242 issue a superfluous error message and then attempt to attach it as
3243 a process. Now, if the second argument begins with a non-digit,
3244 it will be treated as a corefile. If it begins with a digit,
3245 GDB will attempt to attach it as a process, and if no such process
3246 is found, will then attempt to open it as a corefile.
3248 * Changes in ARM configurations.
3250 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3251 configuration is fully multi-arch.
3253 * New native configurations
3255 ARM NetBSD arm*-*-netbsd*
3256 x86 OpenBSD i[3456]86-*-openbsd*
3257 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3258 Sparc64 running FreeBSD sparc64-*-freebsd*
3262 Sanyo XStormy16 xstormy16-elf
3264 * OBSOLETE configurations and files
3266 Configurations that have been declared obsolete in this release have
3267 been commented out. Unless there is activity to revive these
3268 configurations, the next release of GDB will have their sources
3269 permanently REMOVED.
3271 AMD 29k family via UDI a29k-amd-udi, udi29k
3272 A29K VxWorks a29k-*-vxworks
3273 AMD 29000 embedded, using EBMON a29k-none-none
3274 AMD 29000 embedded with COFF a29k-none-coff
3275 AMD 29000 embedded with a.out a29k-none-aout
3277 testsuite/gdb.hp/gdb.threads-hp/ directory
3279 * REMOVED configurations and files
3281 TI TMS320C80 tic80-*-*
3283 PowerPC Solaris powerpcle-*-solaris*
3284 PowerPC Windows NT powerpcle-*-cygwin32
3285 PowerPC Netware powerpc-*-netware*
3286 Harris/CXUX m88k m88*-harris-cxux*
3287 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3288 ns32k-utek-sysv* ns32k-utek-*
3289 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3290 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3291 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3292 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3293 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3295 * Changes to command line processing
3297 The new `--args' feature can be used to specify command-line arguments
3298 for the inferior from gdb's command line.
3300 * Changes to key bindings
3302 There is a new `operate-and-get-next' function bound to `C-o'.
3304 *** Changes in GDB 5.1.1
3306 Fix compile problem on DJGPP.
3308 Fix a problem with floating-point registers on the i386 being
3311 Fix to stop GDB crashing on .debug_str debug info.
3313 Numerous documentation fixes.
3315 Numerous testsuite fixes.
3317 *** Changes in GDB 5.1:
3319 * New native configurations
3321 Alpha FreeBSD alpha*-*-freebsd*
3322 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3323 MIPS GNU/Linux mips*-*-linux*
3324 MIPS SGI Irix 6.x mips*-sgi-irix6*
3325 ia64 AIX ia64-*-aix*
3326 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3330 Motorola 68HC11 and 68HC12 m68hc11-elf
3332 UltraSparc running GNU/Linux sparc64-*-linux*
3334 * OBSOLETE configurations and files
3336 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3337 Harris/CXUX m88k m88*-harris-cxux*
3338 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3339 ns32k-utek-sysv* ns32k-utek-*
3340 TI TMS320C80 tic80-*-*
3342 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3343 PowerPC Solaris powerpcle-*-solaris*
3344 PowerPC Windows NT powerpcle-*-cygwin32
3345 PowerPC Netware powerpc-*-netware*
3346 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3347 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3348 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3349 Apple Macintosh (MPW) host N/A
3351 stuff.c (Program to stuff files into a specially prepared space in kdb)
3352 kdb-start.c (Main loop for the standalone kernel debugger)
3354 Configurations that have been declared obsolete in this release have
3355 been commented out. Unless there is activity to revive these
3356 configurations, the next release of GDB will have their sources
3357 permanently REMOVED.
3359 * REMOVED configurations and files
3361 Altos 3068 m68*-altos-*
3362 Convex c1-*-*, c2-*-*
3364 ARM RISCix arm-*-* (as host)
3368 * GDB has been converted to ISO C.
3370 GDB's source code has been converted to ISO C. In particular, the
3371 sources are fully protoized, and rely on standard headers being
3376 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3378 * The MI enabled by default.
3380 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3381 revised and enabled by default. Packages which use GDB as a debugging
3382 engine behind a UI or another front end are encouraged to switch to
3383 using the GDB/MI interface, instead of the old annotations interface
3384 which is now deprecated.
3386 * Support for debugging Pascal programs.
3388 GDB now includes support for debugging Pascal programs. The following
3389 main features are supported:
3391 - Pascal-specific data types such as sets;
3393 - automatic recognition of Pascal sources based on file-name
3396 - Pascal-style display of data types, variables, and functions;
3398 - a Pascal expression parser.
3400 However, some important features are not yet supported.
3402 - Pascal string operations are not supported at all;
3404 - there are some problems with boolean types;
3406 - Pascal type hexadecimal constants are not supported
3407 because they conflict with the internal variables format;
3409 - support for Pascal objects and classes is not full yet;
3411 - unlike Pascal, GDB is case-sensitive for symbol names.
3413 * Changes in completion.
3415 Commands such as `shell', `run' and `set args', which pass arguments
3416 to inferior programs, now complete on file names, similar to what
3417 users expect at the shell prompt.
3419 Commands which accept locations, such as `disassemble', `print',
3420 `breakpoint', `until', etc. now complete on filenames as well as
3421 program symbols. Thus, if you type "break foob TAB", and the source
3422 files linked into the programs include `foobar.c', that file name will
3423 be one of the candidates for completion. However, file names are not
3424 considered for completion after you typed a colon that delimits a file
3425 name from a name of a function in that file, as in "break foo.c:bar".
3427 `set demangle-style' completes on available demangling styles.
3429 * New platform-independent commands:
3431 It is now possible to define a post-hook for a command as well as a
3432 hook that runs before the command. For more details, see the
3433 documentation of `hookpost' in the GDB manual.
3435 * Changes in GNU/Linux native debugging.
3437 Support for debugging multi-threaded programs has been completely
3438 revised for all platforms except m68k and sparc. You can now debug as
3439 many threads as your system allows you to have.
3441 Attach/detach is supported for multi-threaded programs.
3443 Support for SSE registers was added for x86. This doesn't work for
3444 multi-threaded programs though.
3446 * Changes in MIPS configurations.
3448 Multi-arch support is enabled for all MIPS configurations.
3450 GDB can now be built as native debugger on SGI Irix 6.x systems for
3451 debugging n32 executables. (Debugging 64-bit executables is not yet
3454 * Unified support for hardware watchpoints in all x86 configurations.
3456 Most (if not all) native x86 configurations support hardware-assisted
3457 breakpoints and watchpoints in a unified manner. This support
3458 implements debug register sharing between watchpoints, which allows to
3459 put a virtually infinite number of watchpoints on the same address,
3460 and also supports watching regions up to 16 bytes with several debug
3463 The new maintenance command `maintenance show-debug-regs' toggles
3464 debugging print-outs in functions that insert, remove, and test
3465 watchpoints and hardware breakpoints.
3467 * Changes in the DJGPP native configuration.
3469 New command ``info dos sysinfo'' displays assorted information about
3470 the CPU, OS, memory, and DPMI server.
3472 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3473 display information about segment descriptors stored in GDT, LDT, and
3476 New commands ``info dos pde'' and ``info dos pte'' display entries
3477 from Page Directory and Page Tables (for now works with CWSDPMI only).
3478 New command ``info dos address-pte'' displays the Page Table entry for
3479 a given linear address.
3481 GDB can now pass command lines longer than 126 characters to the
3482 program being debugged (requires an update to the libdbg.a library
3483 which is part of the DJGPP development kit).
3485 DWARF2 debug info is now supported.
3487 It is now possible to `step' and `next' through calls to `longjmp'.
3489 * Changes in documentation.
3491 All GDB documentation was converted to GFDL, the GNU Free
3492 Documentation License.
3494 Tracepoints-related commands are now fully documented in the GDB
3497 TUI, the Text-mode User Interface, is now documented in the manual.
3499 Tracepoints-related commands are now fully documented in the GDB
3502 The "GDB Internals" manual now has an index. It also includes
3503 documentation of `ui_out' functions, GDB coding standards, x86
3504 hardware watchpoints, and memory region attributes.
3506 * GDB's version number moved to ``version.in''
3508 The Makefile variable VERSION has been replaced by the file
3509 ``version.in''. People creating GDB distributions should update the
3510 contents of this file.
3514 GUD support is now a standard part of the EMACS distribution.
3516 *** Changes in GDB 5.0:
3518 * Improved support for debugging FP programs on x86 targets
3520 Unified and much-improved support for debugging floating-point
3521 programs on all x86 targets. In particular, ``info float'' now
3522 displays the FP registers in the same format on all x86 targets, with
3523 greater level of detail.
3525 * Improvements and bugfixes in hardware-assisted watchpoints
3527 It is now possible to watch array elements, struct members, and
3528 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3529 on x86 targets no longer erroneously trigger when the address is
3532 * Improvements in the native DJGPP version of GDB
3534 The distribution now includes all the scripts and auxiliary files
3535 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3536 machines ``out of the box''.
3538 The DJGPP version can now debug programs that use signals. It is
3539 possible to catch signals that happened in the debuggee, deliver
3540 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3541 would kill the program being debugged.) Programs that hook hardware
3542 interrupts (keyboard, timer, etc.) can also be debugged.
3544 It is now possible to debug DJGPP programs that redirect their
3545 standard handles or switch them to raw (as opposed to cooked) mode, or
3546 even close them. The command ``run < foo > bar'' works as expected,
3547 and ``info terminal'' reports useful information about the debuggee's
3548 terminal, including raw/cooked mode, redirection, etc.
3550 The DJGPP version now uses termios functions for console I/O, which
3551 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3554 DOS-style file names with drive letters are now fully supported by
3557 It is now possible to debug DJGPP programs that switch their working
3558 directory. It is also possible to rerun the debuggee any number of
3559 times without restarting GDB; thus, you can use the same setup,
3560 breakpoints, etc. for many debugging sessions.
3562 * New native configurations
3564 ARM GNU/Linux arm*-*-linux*
3565 PowerPC GNU/Linux powerpc-*-linux*
3569 Motorola MCore mcore-*-*
3570 x86 VxWorks i[3456]86-*-vxworks*
3571 PowerPC VxWorks powerpc-*-vxworks*
3572 TI TMS320C80 tic80-*-*
3574 * OBSOLETE configurations
3576 Altos 3068 m68*-altos-*
3577 Convex c1-*-*, c2-*-*
3579 ARM RISCix arm-*-* (as host)
3582 Configurations that have been declared obsolete will be commented out,
3583 but the code will be left in place. If there is no activity to revive
3584 these configurations before the next release of GDB, the sources will
3585 be permanently REMOVED.
3587 * Gould support removed
3589 Support for the Gould PowerNode and NP1 has been removed.
3591 * New features for SVR4
3593 On SVR4 native platforms (such as Solaris), if you attach to a process
3594 without first loading a symbol file, GDB will now attempt to locate and
3595 load symbols from the running process's executable file.
3597 * Many C++ enhancements
3599 C++ support has been greatly improved. Overload resolution now works properly
3600 in almost all cases. RTTI support is on the way.
3602 * Remote targets can connect to a sub-program
3604 A popen(3) style serial-device has been added. This device starts a
3605 sub-process (such as a stand-alone simulator) and then communicates
3606 with that. The sub-program to run is specified using the syntax
3607 ``|<program> <args>'' vis:
3609 (gdb) set remotedebug 1
3610 (gdb) target extended-remote |mn10300-elf-sim program-args
3612 * MIPS 64 remote protocol
3614 A long standing bug in the mips64 remote protocol where by GDB
3615 expected certain 32 bit registers (ex SR) to be transfered as 32
3616 instead of 64 bits has been fixed.
3618 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3619 added to provide backward compatibility with older versions of GDB.
3621 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3623 The command ``set remotebinarydownload'' command has been replaced by
3624 ``set remote X-packet''. Other commands in ``set remote'' family
3625 include ``set remote P-packet''.
3627 * Breakpoint commands accept ranges.
3629 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3630 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3631 ``tracepoint passcount'' also accepts a range of tracepoints.
3633 * ``apropos'' command added.
3635 The ``apropos'' command searches through command names and
3636 documentation strings, printing out matches, making it much easier to
3637 try to find a command that does what you are looking for.
3641 A new machine oriented interface (MI) has been added to GDB. This
3642 interface is designed for debug environments running GDB as a separate
3643 process. This is part of the long term libGDB project. See the
3644 "GDB/MI" chapter of the GDB manual for further information. It can be
3645 enabled by configuring with:
3647 .../configure --enable-gdbmi
3649 *** Changes in GDB-4.18:
3651 * New native configurations
3653 HP-UX 10.20 hppa*-*-hpux10.20
3654 HP-UX 11.x hppa*-*-hpux11.0*
3655 M68K GNU/Linux m68*-*-linux*
3659 Fujitsu FR30 fr30-*-elf*
3660 Intel StrongARM strongarm-*-*
3661 Mitsubishi D30V d30v-*-*
3663 * OBSOLETE configurations
3665 Gould PowerNode, NP1 np1-*-*, pn-*-*
3667 Configurations that have been declared obsolete will be commented out,
3668 but the code will be left in place. If there is no activity to revive
3669 these configurations before the next release of GDB, the sources will
3670 be permanently REMOVED.
3674 As a compatibility experiment, GDB's source files buildsym.h and
3675 buildsym.c have been converted to pure standard C, no longer
3676 containing any K&R compatibility code. We believe that all systems in
3677 use today either come with a standard C compiler, or have a GCC port
3678 available. If this is not true, please report the affected
3679 configuration to bug-gdb@gnu.org immediately. See the README file for
3680 information about getting a standard C compiler if you don't have one
3685 GDB now uses readline 2.2.
3687 * set extension-language
3689 You can now control the mapping between filename extensions and source
3690 languages by using the `set extension-language' command. For instance,
3691 you can ask GDB to treat .c files as C++ by saying
3692 set extension-language .c c++
3693 The command `info extensions' lists all of the recognized extensions
3694 and their associated languages.
3696 * Setting processor type for PowerPC and RS/6000
3698 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3699 you can use the `set processor' command to specify what variant of the
3700 PowerPC family you are debugging. The command
3704 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3705 following PowerPC and RS6000 variants:
3707 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3708 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3710 403GC IBM PowerPC 403GC
3711 505 Motorola PowerPC 505
3712 860 Motorola PowerPC 860 or 850
3713 601 Motorola PowerPC 601
3714 602 Motorola PowerPC 602
3715 603 Motorola/IBM PowerPC 603 or 603e
3716 604 Motorola PowerPC 604 or 604e
3717 750 Motorola/IBM PowerPC 750 or 750
3719 At the moment, this command just tells GDB what to name the
3720 special-purpose processor registers. Since almost all the affected
3721 registers are inaccessible to user-level programs, this command is
3722 only useful for remote debugging in its present form.
3726 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3727 more extensive support for HP-UX. Added features include shared
3728 library support, kernel threads and hardware watchpoints for 11.00,
3729 support for HP's ANSI C and C++ compilers, and a compatibility mode
3730 for xdb and dbx commands.
3734 HP's donation includes the new concept of catchpoints, which is a
3735 generalization of the old catch command. On HP-UX, it is now possible
3736 to catch exec, fork, and vfork, as well as library loading.
3738 This means that the existing catch command has changed; its first
3739 argument now specifies the type of catch to be set up. See the
3740 output of "help catch" for a list of catchpoint types.
3742 * Debugging across forks
3744 On HP-UX, you can choose which process to debug when a fork() happens
3749 HP has donated a curses-based terminal user interface (TUI). To get
3750 it, build with --enable-tui. Although this can be enabled for any
3751 configuration, at present it only works for native HP debugging.
3753 * GDB remote protocol additions
3755 A new protocol packet 'X' that writes binary data is now available.
3756 Default behavior is to try 'X', then drop back to 'M' if the stub
3757 fails to respond. The settable variable `remotebinarydownload'
3758 allows explicit control over the use of 'X'.
3760 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3761 full 64-bit address. The command
3763 set remoteaddresssize 32
3765 can be used to revert to the old behaviour. For existing remote stubs
3766 the change should not be noticed, as the additional address information
3769 In order to assist in debugging stubs, you may use the maintenance
3770 command `packet' to send any text string to the stub. For instance,
3772 maint packet heythere
3774 sends the packet "$heythere#<checksum>". Note that it is very easy to
3775 disrupt a debugging session by sending the wrong packet at the wrong
3778 The compare-sections command allows you to compare section data on the
3779 target to what is in the executable file without uploading or
3780 downloading, by comparing CRC checksums.
3782 * Tracing can collect general expressions
3784 You may now collect general expressions at tracepoints. This requires
3785 further additions to the target-side stub; see tracepoint.c and
3786 doc/agentexpr.texi for further details.
3788 * mask-address variable for Mips
3790 For Mips targets, you may control the zeroing of the upper 32 bits of
3791 a 64-bit address by entering `set mask-address on'. This is mainly
3792 of interest to users of embedded R4xxx and R5xxx processors.
3794 * Higher serial baud rates
3796 GDB's serial code now allows you to specify baud rates 57600, 115200,
3797 230400, and 460800 baud. (Note that your host system may not be able
3798 to achieve all of these rates.)
3802 The i960 configuration now includes an initial implementation of a
3803 builtin simulator, contributed by Jim Wilson.
3806 *** Changes in GDB-4.17:
3808 * New native configurations
3810 Alpha GNU/Linux alpha*-*-linux*
3811 Unixware 2.x i[3456]86-unixware2*
3812 Irix 6.x mips*-sgi-irix6*
3813 PowerPC GNU/Linux powerpc-*-linux*
3814 PowerPC Solaris powerpcle-*-solaris*
3815 Sparc GNU/Linux sparc-*-linux*
3816 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3820 Argonaut Risc Chip (ARC) arc-*-*
3821 Hitachi H8/300S h8300*-*-*
3822 Matsushita MN10200 w/simulator mn10200-*-*
3823 Matsushita MN10300 w/simulator mn10300-*-*
3824 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3825 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3826 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3827 Mitsubishi D10V w/simulator d10v-*-*
3828 Mitsubishi M32R/D w/simulator m32r-*-elf*
3829 Tsqware Sparclet sparclet-*-*
3830 NEC V850 w/simulator v850-*-*
3832 * New debugging protocols
3834 ARM with RDI protocol arm*-*-*
3835 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3836 DDB and LSI variants of PMON protocol mips*-*-*
3837 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3838 PowerPC with SDS protocol powerpc{,le}-*-eabi
3839 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3843 All configurations can now understand and use the DWARF 2 debugging
3844 format. The choice is automatic, if the symbol file contains DWARF 2
3849 GDB now includes basic Java language support. This support is
3850 only useful with Java compilers that produce native machine code.
3852 * solib-absolute-prefix and solib-search-path
3854 For SunOS and SVR4 shared libraries, you may now set the prefix for
3855 loading absolute shared library symbol files, and the search path for
3856 locating non-absolute shared library symbol files.
3858 * Live range splitting
3860 GDB can now effectively debug code for which GCC has performed live
3861 range splitting as part of its optimization. See gdb/doc/LRS for
3862 more details on the expected format of the stabs information.
3866 GDB's support for the GNU Hurd, including thread debugging, has been
3867 updated to work with current versions of the Hurd.
3871 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3872 instruction set. ARM GDB automatically detects when Thumb
3873 instructions are in use, and adjusts disassembly and backtracing
3878 GDB's MIPS target configurations now handle the MIP16 16-bit
3883 GDB now includes support for overlays; if an executable has been
3884 linked such that multiple sections are based at the same address, GDB
3885 will decide which section to use for symbolic info. You can choose to
3886 control the decision manually, using overlay commands, or implement
3887 additional target-side support and use "overlay load-target" to bring
3888 in the overlay mapping. Do "help overlay" for more detail.
3892 The command "info symbol <address>" displays information about
3893 the symbol at the specified address.
3897 The standard remote protocol now includes an extension that allows
3898 asynchronous collection and display of trace data. This requires
3899 extensive support in the target-side debugging stub. Tracing mode
3900 includes a new interaction mode in GDB and new commands: see the
3901 file tracepoint.c for more details.
3905 Configurations for embedded MIPS now include a simulator contributed
3906 by Cygnus Solutions. The simulator supports the instruction sets
3907 of most MIPS variants.
3911 Sparc configurations may now include the ERC32 simulator contributed
3912 by the European Space Agency. The simulator is not built into
3913 Sparc targets by default; configure with --enable-sim to include it.
3917 For target configurations that may include multiple variants of a
3918 basic architecture (such as MIPS and SH), you may now set the
3919 architecture explicitly. "set arch" sets, "info arch" lists
3920 the possible architectures.
3922 *** Changes in GDB-4.16:
3924 * New native configurations
3926 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3927 M68K NetBSD m68k-*-netbsd*
3928 PowerPC AIX 4.x powerpc-*-aix*
3929 PowerPC MacOS powerpc-*-macos*
3930 PowerPC Windows NT powerpcle-*-cygwin32
3931 RS/6000 AIX 4.x rs6000-*-aix4*
3935 ARM with RDP protocol arm-*-*
3936 I960 with MON960 i960-*-coff
3937 MIPS VxWorks mips*-*-vxworks*
3938 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3939 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3941 Matra Sparclet sparclet-*-*
3945 The powerpc-eabi configuration now includes the PSIM simulator,
3946 contributed by Andrew Cagney, with assistance from Mike Meissner.
3947 PSIM is a very elaborate model of the PowerPC, including not only
3948 basic instruction set execution, but also details of execution unit
3949 performance and I/O hardware. See sim/ppc/README for more details.
3953 GDB now works with Solaris 2.5.
3955 * Windows 95/NT native
3957 GDB will now work as a native debugger on Windows 95 and Windows NT.
3958 To build it from source, you must use the "gnu-win32" environment,
3959 which uses a DLL to emulate enough of Unix to run the GNU tools.
3960 Further information, binaries, and sources are available at
3961 ftp.cygnus.com, under pub/gnu-win32.
3963 * dont-repeat command
3965 If a user-defined command includes the command `dont-repeat', then the
3966 command will not be repeated if the user just types return. This is
3967 useful if the command is time-consuming to run, so that accidental
3968 extra keystrokes don't run the same command many times.
3970 * Send break instead of ^C
3972 The standard remote protocol now includes an option to send a break
3973 rather than a ^C to the target in order to interrupt it. By default,
3974 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3976 * Remote protocol timeout
3978 The standard remote protocol includes a new variable `remotetimeout'
3979 that allows you to set the number of seconds before GDB gives up trying
3980 to read from the target. The default value is 2.
3982 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3984 By default GDB will automatically keep track of objects as they are
3985 loaded and unloaded by the dynamic linker. By using the command `set
3986 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3987 when shared library events occur, thus allowing you to set breakpoints
3988 in shared libraries which are explicitly loaded by the inferior.
3990 Note this feature does not work on hpux8. On hpux9 you must link
3991 /usr/lib/end.o into your program. This feature should work
3992 automatically on hpux10.
3994 * Irix 5.x hardware watchpoint support
3996 Irix 5 configurations now support the use of hardware watchpoints.
3998 * Mips protocol "SYN garbage limit"
4000 When debugging a Mips target using the `target mips' protocol, you
4001 may set the number of characters that GDB will ignore by setting
4002 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4003 every character. The default value is 1050.
4005 * Recording and replaying remote debug sessions
4007 If you set `remotelogfile' to the name of a file, gdb will write to it
4008 a recording of a remote debug session. This recording may then be
4009 replayed back to gdb using "gdbreplay". See gdbserver/README for
4010 details. This is useful when you have a problem with GDB while doing
4011 remote debugging; you can make a recording of the session and send it
4012 to someone else, who can then recreate the problem.
4014 * Speedups for remote debugging
4016 GDB includes speedups for downloading and stepping MIPS systems using
4017 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4018 and more efficient S-record downloading.
4020 * Memory use reductions and statistics collection
4022 GDB now uses less memory and reports statistics about memory usage.
4023 Try the `maint print statistics' command, for example.
4025 *** Changes in GDB-4.15:
4027 * Psymtabs for XCOFF
4029 The symbol reader for AIX GDB now uses partial symbol tables. This
4030 can greatly improve startup time, especially for large executables.
4032 * Remote targets use caching
4034 Remote targets now use a data cache to speed up communication with the
4035 remote side. The data cache could lead to incorrect results because
4036 it doesn't know about volatile variables, thus making it impossible to
4037 debug targets which use memory mapped I/O devices. `set remotecache
4038 off' turns the the data cache off.
4040 * Remote targets may have threads
4042 The standard remote protocol now includes support for multiple threads
4043 in the target system, using new protocol commands 'H' and 'T'. See
4044 gdb/remote.c for details.
4048 If GDB is configured with `--enable-netrom', then it will include
4049 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4050 acts as though it is a bank of ROM on the target board, but you can
4051 write into it over the network. GDB's support consists only of
4052 support for fast loading into the emulated ROM; to debug, you must use
4053 another protocol, such as standard remote protocol. The usual
4054 sequence is something like
4056 target nrom <netrom-hostname>
4058 target remote <netrom-hostname>:1235
4062 GDB now includes support for the Apple Macintosh, as a host only. It
4063 may be run as either an MPW tool or as a standalone application, and
4064 it can debug through the serial port. All the usual GDB commands are
4065 available, but to the target command, you must supply "serial" as the
4066 device type instead of "/dev/ttyXX". See mpw-README in the main
4067 directory for more information on how to build. The MPW configuration
4068 scripts */mpw-config.in support only a few targets, and only the
4069 mips-idt-ecoff target has been tested.
4073 GDB configuration now uses autoconf. This is not user-visible,
4074 but does simplify configuration and building.
4078 GDB now supports hpux10.
4080 *** Changes in GDB-4.14:
4082 * New native configurations
4084 x86 FreeBSD i[345]86-*-freebsd
4085 x86 NetBSD i[345]86-*-netbsd
4086 NS32k NetBSD ns32k-*-netbsd
4087 Sparc NetBSD sparc-*-netbsd
4091 A29K VxWorks a29k-*-vxworks
4092 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4093 CPU32 EST-300 emulator m68*-*-est*
4094 PowerPC ELF powerpc-*-elf
4097 * Alpha OSF/1 support for procfs
4099 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4100 possible to attach to running processes. As the mounting of the /proc
4101 filesystem is optional on the Alpha, GDB automatically determines
4102 the availability of /proc during startup. This can lead to problems
4103 if /proc is unmounted after GDB has been started.
4105 * Arguments to user-defined commands
4107 User commands may accept up to 10 arguments separated by whitespace.
4108 Arguments are accessed within the user command via $arg0..$arg9. A
4111 print $arg0 + $arg1 + $arg2
4113 To execute the command use:
4116 Defines the command "adder" which prints the sum of its three arguments.
4117 Note the arguments are text substitutions, so they may reference variables,
4118 use complex expressions, or even perform inferior function calls.
4120 * New `if' and `while' commands
4122 This makes it possible to write more sophisticated user-defined
4123 commands. Both commands take a single argument, which is the
4124 expression to evaluate, and must be followed by the commands to
4125 execute, one per line, if the expression is nonzero, the list being
4126 terminated by the word `end'. The `if' command list may include an
4127 `else' word, which causes the following commands to be executed only
4128 if the expression is zero.
4130 * Fortran source language mode
4132 GDB now includes partial support for Fortran 77. It will recognize
4133 Fortran programs and can evaluate a subset of Fortran expressions, but
4134 variables and functions may not be handled correctly. GDB will work
4135 with G77, but does not yet know much about symbols emitted by other
4138 * Better HPUX support
4140 Most debugging facilities now work on dynamic executables for HPPAs
4141 running hpux9 or later. You can attach to running dynamically linked
4142 processes, but by default the dynamic libraries will be read-only, so
4143 for instance you won't be able to put breakpoints in them. To change
4144 that behavior do the following before running the program:
4150 This will cause the libraries to be mapped private and read-write.
4151 To revert to the normal behavior, do this:
4157 You cannot set breakpoints or examine data in the library until after
4158 the library is loaded if the function/data symbols do not have
4161 GDB can now also read debug symbols produced by the HP C compiler on
4162 HPPAs (sorry, no C++, Fortran or 68k support).
4164 * Target byte order now dynamically selectable
4166 You can choose which byte order to use with a target system, via the
4167 commands "set endian big" and "set endian little", and you can see the
4168 current setting by using "show endian". You can also give the command
4169 "set endian auto", in which case GDB will use the byte order
4170 associated with the executable. Currently, only embedded MIPS
4171 configurations support dynamic selection of target byte order.
4173 * New DOS host serial code
4175 This version uses DPMI interrupts to handle buffered I/O, so you
4176 no longer need to run asynctsr when debugging boards connected to
4179 *** Changes in GDB-4.13:
4181 * New "complete" command
4183 This lists all the possible completions for the rest of the line, if it
4184 were to be given as a command itself. This is intended for use by emacs.
4186 * Trailing space optional in prompt
4188 "set prompt" no longer adds a space for you after the prompt you set. This
4189 allows you to set a prompt which ends in a space or one that does not.
4191 * Breakpoint hit counts
4193 "info break" now displays a count of the number of times the breakpoint
4194 has been hit. This is especially useful in conjunction with "ignore"; you
4195 can ignore a large number of breakpoint hits, look at the breakpoint info
4196 to see how many times the breakpoint was hit, then run again, ignoring one
4197 less than that number, and this will get you quickly to the last hit of
4200 * Ability to stop printing at NULL character
4202 "set print null-stop" will cause GDB to stop printing the characters of
4203 an array when the first NULL is encountered. This is useful when large
4204 arrays actually contain only short strings.
4206 * Shared library breakpoints
4208 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4209 breakpoints in shared libraries before the executable is run.
4211 * Hardware watchpoints
4213 There is a new hardware breakpoint for the watch command for sparclite
4214 targets. See gdb/sparclite/hw_breakpoint.note.
4216 Hardware watchpoints are also now supported under GNU/Linux.
4220 Annotations have been added. These are for use with graphical interfaces,
4221 and are still experimental. Currently only gdba.el uses these.
4223 * Improved Irix 5 support
4225 GDB now works properly with Irix 5.2.
4227 * Improved HPPA support
4229 GDB now works properly with the latest GCC and GAS.
4231 * New native configurations
4233 Sequent PTX4 i[34]86-sequent-ptx4
4234 HPPA running OSF/1 hppa*-*-osf*
4235 Atari TT running SVR4 m68*-*-sysv4*
4236 RS/6000 LynxOS rs6000-*-lynxos*
4240 OS/9000 i[34]86-*-os9k
4241 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4244 * Hitachi SH7000 and E7000-PC ICE support
4246 There is now support for communicating with the Hitachi E7000-PC ICE.
4247 This is available automatically when GDB is configured for the SH.
4251 As usual, a variety of small fixes and improvements, both generic
4252 and configuration-specific. See the ChangeLog for more detail.
4254 *** Changes in GDB-4.12:
4256 * Irix 5 is now supported
4260 GDB-4.12 on the HPPA has a number of changes which make it unable
4261 to debug the output from the currently released versions of GCC and
4262 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4263 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4264 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4267 *** Changes in GDB-4.11:
4269 * User visible changes:
4273 The "set remotedebug" option is now consistent between the mips remote
4274 target, remote targets using the gdb-specific protocol, UDI (AMD's
4275 debug protocol for the 29k) and the 88k bug monitor. It is now an
4276 integer specifying a debug level (normally 0 or 1, but 2 means more
4277 debugging info for the mips target).
4279 * DEC Alpha native support
4281 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4282 debug info, but GDB works fairly well with the DEC compiler and should
4283 work with a future GCC release. See the README file for a few
4284 Alpha-specific notes.
4286 * Preliminary thread implementation
4288 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4290 * LynxOS native and target support for 386
4292 This release has been hosted on LynxOS 2.2, and also can be configured
4293 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4296 * Improvements in C++ mangling/demangling.
4298 This release has much better g++ debugging, specifically in name
4299 mangling/demangling, virtual function calls, print virtual table,
4300 call methods, ...etc.
4302 *** Changes in GDB-4.10:
4304 * User visible changes:
4306 Remote debugging using the GDB-specific (`target remote') protocol now
4307 supports the `load' command. This is only useful if you have some
4308 other way of getting the stub to the target system, and you can put it
4309 somewhere in memory where it won't get clobbered by the download.
4311 Filename completion now works.
4313 When run under emacs mode, the "info line" command now causes the
4314 arrow to point to the line specified. Also, "info line" prints
4315 addresses in symbolic form (as well as hex).
4317 All vxworks based targets now support a user settable option, called
4318 vxworks-timeout. This option represents the number of seconds gdb
4319 should wait for responses to rpc's. You might want to use this if
4320 your vxworks target is, perhaps, a slow software simulator or happens
4321 to be on the far side of a thin network line.
4325 This release contains support for using a DEC alpha as a GDB host for
4326 cross debugging. Native alpha debugging is not supported yet.
4329 *** Changes in GDB-4.9:
4333 This is the first GDB release which is accompanied by a matching testsuite.
4334 The testsuite requires installation of dejagnu, which should be available
4335 via ftp from most sites that carry GNU software.
4339 'Cfront' style demangling has had its name changed to 'ARM' style, to
4340 emphasize that it was written from the specifications in the C++ Annotated
4341 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4342 disclaimers, it still generated too much confusion with users attempting to
4343 use gdb with AT&T cfront.
4347 GDB now uses a standard remote interface to a simulator library.
4348 So far, the library contains simulators for the Zilog Z8001/2, the
4349 Hitachi H8/300, H8/500 and Super-H.
4351 * New targets supported
4353 H8/300 simulator h8300-hitachi-hms or h8300hms
4354 H8/500 simulator h8500-hitachi-hms or h8500hms
4355 SH simulator sh-hitachi-hms or sh
4356 Z8000 simulator z8k-zilog-none or z8ksim
4357 IDT MIPS board over serial line mips-idt-ecoff
4359 Cross-debugging to GO32 targets is supported. It requires a custom
4360 version of the i386-stub.c module which is integrated with the
4361 GO32 memory extender.
4363 * New remote protocols
4365 MIPS remote debugging protocol.
4367 * New source languages supported
4369 This version includes preliminary support for Chill, a Pascal like language
4370 used by telecommunications companies. Chill support is also being integrated
4371 into the GNU compiler, but we don't know when it will be publically available.
4374 *** Changes in GDB-4.8:
4376 * HP Precision Architecture supported
4378 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4379 version of this support was available as a set of patches from the
4380 University of Utah. GDB does not support debugging of programs
4381 compiled with the HP compiler, because HP will not document their file
4382 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4383 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4385 Many problems in the preliminary version have been fixed.
4387 * Faster and better demangling
4389 We have improved template demangling and fixed numerous bugs in the GNU style
4390 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4391 character types (wchar_t) are now supported. Demangling of each symbol is now
4392 only done once, and is cached when the symbol table for a file is read in.
4393 This results in a small increase in memory usage for C programs, a moderate
4394 increase in memory usage for C++ programs, and a fantastic speedup in
4397 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4398 from the specifications in the Annotated Reference Manual, which AT&T's
4399 compiler does not actually implement.
4401 * G++ multiple inheritance compiler problem
4403 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4404 inheritance lattices was reworked to properly discover ambiguities. We
4405 recently found an example which causes this new algorithm to fail in a
4406 very subtle way, producing bad debug information for those classes.
4407 The file 'gcc.patch' (in this directory) can be applied to gcc to
4408 circumvent the problem. A future GCC release will contain a complete
4411 The previous G++ debug info problem (mentioned below for the gdb-4.7
4412 release) is fixed in gcc version 2.3.2.
4414 * Improved configure script
4416 The `configure' script will now attempt to guess your system type if
4417 you don't supply a host system type. The old scheme of supplying a
4418 host system triplet is preferable over using this. All the magic is
4419 done in the new `config.guess' script. Examine it for details.
4421 We have also brought our configure script much more in line with the FSF's
4422 version. It now supports the --with-xxx options. In particular,
4423 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4424 The resulting GDB will not be able to read arbitrary object file formats --
4425 only the format ``expected'' to be used on the configured target system.
4426 We hope to make this the default in a future release.
4428 * Documentation improvements
4430 There's new internal documentation on how to modify GDB, and how to
4431 produce clean changes to the code. We implore people to read it
4432 before submitting changes.
4434 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4435 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4436 `info' files are also provided. To build `info' files from scratch,
4437 you will need the latest `makeinfo' release, which will be available in
4438 a future texinfo-X.Y release.
4440 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4441 We're not sure exactly which versions have this problem, but it has
4442 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4443 or better. If that isn't possible, there is a patch in
4444 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4445 around this problem.
4449 GDB now supports array constants that can be used in expressions typed in by
4450 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4451 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4454 The new directory `gdb/sparclite' contains a program that demonstrates
4455 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4457 * New native hosts supported
4459 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4460 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4462 * New targets supported
4464 AMD 29k family via UDI a29k-amd-udi or udi29k
4466 * New file formats supported
4468 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4469 HPUX core files, and SCO 3.2v2 core files.
4473 Attaching to processes now works again; thanks for the many bug reports.
4475 We have also stomped on a bunch of core dumps caused by
4476 printf_filtered("%s") problems.
4478 We eliminated a copyright problem on the rpc and ptrace header files
4479 for VxWorks, which was discovered at the last minute during the 4.7
4480 release. You should now be able to build a VxWorks GDB.
4482 You can now interrupt gdb while an attached process is running. This
4483 will cause the attached process to stop, and give control back to GDB.
4485 We fixed problems caused by using too many file descriptors
4486 for reading symbols from object files and libraries. This was
4487 especially a problem for programs that used many (~100) shared
4490 The `step' command now only enters a subroutine if there is line number
4491 information for the subroutine. Otherwise it acts like the `next'
4492 command. Previously, `step' would enter subroutines if there was
4493 any debugging information about the routine. This avoids problems
4494 when using `cc -g1' on MIPS machines.
4496 * Internal improvements
4498 GDB's internal interfaces have been improved to make it easier to support
4499 debugging of multiple languages in the future.
4501 GDB now uses a common structure for symbol information internally.
4502 Minimal symbols (derived from linkage symbols in object files), partial
4503 symbols (from a quick scan of debug information), and full symbols
4504 contain a common subset of information, making it easier to write
4505 shared code that handles any of them.
4507 * New command line options
4509 We now accept --silent as an alias for --quiet.
4513 The memory-mapped-malloc library is now licensed under the GNU Library
4514 General Public License.
4516 *** Changes in GDB-4.7:
4518 * Host/native/target split
4520 GDB has had some major internal surgery to untangle the support for
4521 hosts and remote targets. Now, when you configure GDB for a remote
4522 target, it will no longer load in all of the support for debugging
4523 local programs on the host. When fully completed and tested, this will
4524 ensure that arbitrary host/target combinations are possible.
4526 The primary conceptual shift is to separate the non-portable code in
4527 GDB into three categories. Host specific code is required any time GDB
4528 is compiled on that host, regardless of the target. Target specific
4529 code relates to the peculiarities of the target, but can be compiled on
4530 any host. Native specific code is everything else: it can only be
4531 built when the host and target are the same system. Child process
4532 handling and core file support are two common `native' examples.
4534 GDB's use of /proc for controlling Unix child processes is now cleaner.
4535 It has been split out into a single module under the `target_ops' vector,
4536 plus two native-dependent functions for each system that uses /proc.
4538 * New hosts supported
4540 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4541 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4542 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4544 * New targets supported
4546 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4547 68030 and CPU32 m68030-*-*, m68332-*-*
4549 * New native hosts supported
4551 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4552 (386bsd is not well tested yet)
4553 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4555 * New file formats supported
4557 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4558 supports reading of `a.out.adobe' object files, which are an a.out
4559 format extended with minimal information about multiple sections.
4563 `show copying' is the same as the old `info copying'.
4564 `show warranty' is the same as `info warrantee'.
4565 These were renamed for consistency. The old commands continue to work.
4567 `info handle' is a new alias for `info signals'.
4569 You can now define pre-command hooks, which attach arbitrary command
4570 scripts to any command. The commands in the hook will be executed
4571 prior to the user's command. You can also create a hook which will be
4572 executed whenever the program stops. See gdb.texinfo.
4576 We now deal with Cfront style name mangling, and can even extract type
4577 info from mangled symbols. GDB can automatically figure out which
4578 symbol mangling style your C++ compiler uses.
4580 Calling of methods and virtual functions has been improved as well.
4584 The crash that occured when debugging Sun Ansi-C compiled binaries is
4585 fixed. This was due to mishandling of the extra N_SO stabs output
4588 We also finally got Ultrix 4.2 running in house, and fixed core file
4589 support, with help from a dozen people on the net.
4591 John M. Farrell discovered that the reason that single-stepping was so
4592 slow on all of the Mips based platforms (primarily SGI and DEC) was
4593 that we were trying to demangle and lookup a symbol used for internal
4594 purposes on every instruction that was being stepped through. Changing
4595 the name of that symbol so that it couldn't be mistaken for a C++
4596 mangled symbol sped things up a great deal.
4598 Rich Pixley sped up symbol lookups in general by getting much smarter
4599 about when C++ symbol mangling is necessary. This should make symbol
4600 completion (TAB on the command line) much faster. It's not as fast as
4601 we'd like, but it's significantly faster than gdb-4.6.
4605 A new user controllable variable 'call_scratch_address' can
4606 specify the location of a scratch area to be used when GDB
4607 calls a function in the target. This is necessary because the
4608 usual method of putting the scratch area on the stack does not work
4609 in systems that have separate instruction and data spaces.
4611 We integrated changes to support the 29k UDI (Universal Debugger
4612 Interface), but discovered at the last minute that we didn't have all
4613 of the appropriate copyright paperwork. We are working with AMD to
4614 resolve this, and hope to have it available soon.
4618 We have sped up the remote serial line protocol, especially for targets
4619 with lots of registers. It now supports a new `expedited status' ('T')
4620 message which can be used in place of the existing 'S' status message.
4621 This allows the remote stub to send only the registers that GDB
4622 needs to make a quick decision about single-stepping or conditional
4623 breakpoints, eliminating the need to fetch the entire register set for
4624 each instruction being stepped through.
4626 The GDB remote serial protocol now implements a write-through cache for
4627 registers, only re-reading the registers if the target has run.
4629 There is also a new remote serial stub for SPARC processors. You can
4630 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4631 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4632 processor with a serial port.
4636 Configure.in files have become much easier to read and modify. A new
4637 `table driven' format makes it more obvious what configurations are
4638 supported, and what files each one uses.
4642 There is a new opcodes library which will eventually contain all of the
4643 disassembly routines and opcode tables. At present, it only contains
4644 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4645 disassembler (binutils/objdump) to share these routines.
4647 The libiberty library is now copylefted under the GNU Library General
4648 Public License. This allows more liberal use, and was done so libg++
4649 can use it. This makes no difference to GDB, since the Library License
4650 grants all the rights from the General Public License.
4654 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4655 reference to the stabs symbol info used by the debugger. It is (as far
4656 as we know) the only published document on this fascinating topic. We
4657 encourage you to read it, compare it to the stabs information on your
4658 system, and send improvements on the document in general (to
4659 bug-gdb@prep.ai.mit.edu).
4661 And, of course, many bugs have been fixed.
4664 *** Changes in GDB-4.6:
4666 * Better support for C++ function names
4668 GDB now accepts as input the "demangled form" of C++ overloaded function
4669 names and member function names, and can do command completion on such names
4670 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4671 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4672 Make use of command completion, it is your friend.
4674 GDB also now accepts a variety of C++ mangled symbol formats. They are
4675 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4676 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4677 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4678 for the list of formats.
4680 * G++ symbol mangling problem
4682 Recent versions of gcc have a bug in how they emit debugging information for
4683 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4684 directory) can be applied to gcc to fix the problem. Alternatively, if you
4685 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4686 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4687 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4690 * New 'maintenance' command
4692 All of the commands related to hacking GDB internals have been moved out of
4693 the main command set, and now live behind the 'maintenance' command. This
4694 can also be abbreviated as 'mt'. The following changes were made:
4696 dump-me -> maintenance dump-me
4697 info all-breakpoints -> maintenance info breakpoints
4698 printmsyms -> maintenance print msyms
4699 printobjfiles -> maintenance print objfiles
4700 printpsyms -> maintenance print psymbols
4701 printsyms -> maintenance print symbols
4703 The following commands are new:
4705 maintenance demangle Call internal GDB demangler routine to
4706 demangle a C++ link name and prints the result.
4707 maintenance print type Print a type chain for a given symbol
4709 * Change to .gdbinit file processing
4711 We now read the $HOME/.gdbinit file before processing the argv arguments
4712 (e.g. reading symbol files or core files). This allows global parameters to
4713 be set, which will apply during the symbol reading. The ./.gdbinit is still
4714 read after argv processing.
4716 * New hosts supported
4718 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4720 GNU/Linux support i386-unknown-linux or linux
4722 We are also including code to support the HP/PA running BSD and HPUX. This
4723 is almost guaranteed not to work, as we didn't have time to test or build it
4724 for this release. We are including it so that the more adventurous (or
4725 masochistic) of you can play with it. We also had major problems with the
4726 fact that the compiler that we got from HP doesn't support the -g option.
4729 * New targets supported
4731 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4733 * More smarts about finding #include files
4735 GDB now remembers the compilation directory for all include files, and for
4736 all files from which C is generated (like yacc and lex sources). This
4737 greatly improves GDB's ability to find yacc/lex sources, and include files,
4738 especially if you are debugging your program from a directory different from
4739 the one that contains your sources.
4741 We also fixed a bug which caused difficulty with listing and setting
4742 breakpoints in include files which contain C code. (In the past, you had to
4743 try twice in order to list an include file that you hadn't looked at before.)
4745 * Interesting infernals change
4747 GDB now deals with arbitrary numbers of sections, where the symbols for each
4748 section must be relocated relative to that section's landing place in the
4749 target's address space. This work was needed to support ELF with embedded
4750 stabs used by Solaris-2.0.
4752 * Bug fixes (of course!)
4754 There have been loads of fixes for the following things:
4755 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4756 i960, stabs, DOS(GO32), procfs, etc...
4758 See the ChangeLog for details.
4760 *** Changes in GDB-4.5:
4762 * New machines supported (host and target)
4764 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4766 SGI Irix-4.x mips-sgi-irix4 or iris4
4768 * New malloc package
4770 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4771 Mmalloc is capable of handling mutiple heaps of memory. It is also
4772 capable of saving a heap to a file, and then mapping it back in later.
4773 This can be used to greatly speedup the startup of GDB by using a
4774 pre-parsed symbol table which lives in a mmalloc managed heap. For
4775 more details, please read mmalloc/mmalloc.texi.
4779 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4780 'help info proc' for details.
4782 * MIPS ecoff symbol table format
4784 The code that reads MIPS symbol table format is now supported on all hosts.
4785 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4788 * File name changes for MS-DOS
4790 Many files in the config directories have been renamed to make it easier to
4791 support GDB on MS-DOSe systems (which have very restrictive file name
4792 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4793 environment) is close to working but has some remaining problems. Note
4794 that debugging of DOS programs is not supported, due to limitations
4795 in the ``operating system'', but it can be used to host cross-debugging.
4797 * Cross byte order fixes
4799 Many fixes have been made to support cross debugging of Sparc and MIPS
4800 targets from hosts whose byte order differs.
4802 * New -mapped and -readnow options
4804 If memory-mapped files are available on your system through the 'mmap'
4805 system call, you can use the -mapped option on the `file' or
4806 `symbol-file' commands to cause GDB to write the symbols from your
4807 program into a reusable file. If the program you are debugging is
4808 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4809 Future GDB debugging sessions will notice the presence of this file,
4810 and will quickly map in symbol information from it, rather than reading
4811 the symbol table from the executable program. Using the '-mapped'
4812 option in a GDB `file' or `symbol-file' command has the same effect as
4813 starting GDB with the '-mapped' command-line option.
4815 You can cause GDB to read the entire symbol table immediately by using
4816 the '-readnow' option with any of the commands that load symbol table
4817 information (or on the GDB command line). This makes the command
4818 slower, but makes future operations faster.
4820 The -mapped and -readnow options are typically combined in order to
4821 build a `fred.syms' file that contains complete symbol information.
4822 A simple GDB invocation to do nothing but build a `.syms' file for future
4825 gdb -batch -nx -mapped -readnow programname
4827 The `.syms' file is specific to the host machine on which GDB is run.
4828 It holds an exact image of GDB's internal symbol table. It cannot be
4829 shared across multiple host platforms.
4831 * longjmp() handling
4833 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4834 siglongjmp() without losing control. This feature has not yet been ported to
4835 all systems. It currently works on many 386 platforms, all MIPS-based
4836 platforms (SGI, DECstation, etc), and Sun3/4.
4840 Preliminary work has been put in to support the new Solaris OS from Sun. At
4841 this time, it can control and debug processes, but it is not capable of
4846 As always, many many bug fixes. The major areas were with g++, and mipsread.
4847 People using the MIPS-based platforms should experience fewer mysterious
4848 crashes and trashed symbol tables.
4850 *** Changes in GDB-4.4:
4852 * New machines supported (host and target)
4854 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4856 BSD Reno on Vax vax-dec-bsd
4857 Ultrix on Vax vax-dec-ultrix
4859 * New machines supported (target)
4861 AMD 29000 embedded, using EBMON a29k-none-none
4865 GDB continues to improve its handling of C++. `References' work better.
4866 The demangler has also been improved, and now deals with symbols mangled as
4867 per the Annotated C++ Reference Guide.
4869 GDB also now handles `stabs' symbol information embedded in MIPS
4870 `ecoff' symbol tables. Since the ecoff format was not easily
4871 extensible to handle new languages such as C++, this appeared to be a
4872 good way to put C++ debugging info into MIPS binaries. This option
4873 will be supported in the GNU C compiler, version 2, when it is
4876 * New features for SVR4
4878 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4879 shared libraries. Debugging dynamically linked programs should present
4880 only minor differences from debugging statically linked programs.
4882 The `info proc' command will print out information about any process
4883 on an SVR4 system (including the one you are debugging). At the moment,
4884 it prints the address mappings of the process.
4886 If you bring up GDB on another SVR4 system, please send mail to
4887 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4889 * Better dynamic linking support in SunOS
4891 Reading symbols from shared libraries which contain debugging symbols
4892 now works properly. However, there remain issues such as automatic
4893 skipping of `transfer vector' code during function calls, which
4894 make it harder to debug code in a shared library, than to debug the
4895 same code linked statically.
4899 GDB is now using the latest `getopt' routines from the FSF. This
4900 version accepts the -- prefix for options with long names. GDB will
4901 continue to accept the old forms (-option and +option) as well.
4902 Various single letter abbreviations for options have been explicity
4903 added to the option table so that they won't get overshadowed in the
4904 future by other options that begin with the same letter.
4908 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4909 Many assorted bugs have been handled. Many more remain to be handled.
4910 See the various ChangeLog files (primarily in gdb and bfd) for details.
4913 *** Changes in GDB-4.3:
4915 * New machines supported (host and target)
4917 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4918 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4919 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4921 * Almost SCO Unix support
4923 We had hoped to support:
4924 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4925 (except for core file support), but we discovered very late in the release
4926 that it has problems with process groups that render gdb unusable. Sorry
4927 about that. I encourage people to fix it and post the fixes.
4929 * Preliminary ELF and DWARF support
4931 GDB can read ELF object files on System V Release 4, and can handle
4932 debugging records for C, in DWARF format, in ELF files. This support
4933 is preliminary. If you bring up GDB on another SVR4 system, please
4934 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4939 GDB now uses the latest `readline' library. One user-visible change
4940 is that two tabs will list possible command completions, which previously
4941 required typing M-? (meta-question mark, or ESC ?).
4945 The `stepi' bug that many of you noticed has been squashed.
4946 Many bugs in C++ have been handled. Many more remain to be handled.
4947 See the various ChangeLog files (primarily in gdb and bfd) for details.
4949 * State of the MIPS world (in case you wondered):
4951 GDB can understand the symbol tables emitted by the compilers
4952 supplied by most vendors of MIPS-based machines, including DEC. These
4953 symbol tables are in a format that essentially nobody else uses.
4955 Some versions of gcc come with an assembler post-processor called
4956 mips-tfile. This program is required if you want to do source-level
4957 debugging of gcc-compiled programs. I believe FSF does not ship
4958 mips-tfile with gcc version 1, but it will eventually come with gcc
4961 Debugging of g++ output remains a problem. g++ version 1.xx does not
4962 really support it at all. (If you're lucky, you should be able to get
4963 line numbers and stack traces to work, but no parameters or local
4964 variables.) With some work it should be possible to improve the
4967 When gcc version 2 is released, you will have somewhat better luck.
4968 However, even then you will get confusing results for inheritance and
4971 We will eventually provide full debugging of g++ output on
4972 DECstations. This will probably involve some kind of stabs-in-ecoff
4973 encapulation, but the details have not been worked out yet.
4976 *** Changes in GDB-4.2:
4978 * Improved configuration
4980 Only one copy of `configure' exists now, and it is not self-modifying.
4981 Porting BFD is simpler.
4985 The `step' and `next' commands now only stop at the first instruction
4986 of a source line. This prevents the multiple stops that used to occur
4987 in switch statements, for-loops, etc. `Step' continues to stop if a
4988 function that has debugging information is called within the line.
4992 Lots of small bugs fixed. More remain.
4994 * New host supported (not target)
4996 Intel 386 PC clone running Mach i386-none-mach
4999 *** Changes in GDB-4.1:
5001 * Multiple source language support
5003 GDB now has internal scaffolding to handle several source languages.
5004 It determines the type of each source file from its filename extension,
5005 and will switch expression parsing and number formatting to match the
5006 language of the function in the currently selected stack frame.
5007 You can also specifically set the language to be used, with
5008 `set language c' or `set language modula-2'.
5012 GDB now has preliminary support for the GNU Modula-2 compiler,
5013 currently under development at the State University of New York at
5014 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5015 continue through the fall of 1991 and into 1992.
5017 Other Modula-2 compilers are currently not supported, and attempting to
5018 debug programs compiled with them will likely result in an error as the
5019 symbol table is read. Feel free to work on it, though!
5021 There are hooks in GDB for strict type checking and range checking,
5022 in the `Modula-2 philosophy', but they do not currently work.
5026 GDB can now write to executable and core files (e.g. patch
5027 a variable's value). You must turn this switch on, specify
5028 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5029 by assigning a new value to a variable. Modifications take
5032 * Automatic SunOS shared library reading
5034 When you run your program, GDB automatically determines where its
5035 shared libraries (if any) have been loaded, and reads their symbols.
5036 The `share' command is no longer needed. This also works when
5037 examining core files.
5041 You can specify the number of lines that the `list' command shows.
5044 * New machines supported (host and target)
5046 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5047 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5048 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5050 * New hosts supported (not targets)
5052 IBM RT/PC: romp-ibm-aix or rtpc
5054 * New targets supported (not hosts)
5056 AMD 29000 embedded with COFF a29k-none-coff
5057 AMD 29000 embedded with a.out a29k-none-aout
5058 Ultracomputer remote kernel debug a29k-nyu-kern
5060 * New remote interfaces
5066 *** Changes in GDB-4.0:
5070 Wide output is wrapped at good places to make the output more readable.
5072 Gdb now supports cross-debugging from a host machine of one type to a
5073 target machine of another type. Communication with the target system
5074 is over serial lines. The ``target'' command handles connecting to the
5075 remote system; the ``load'' command will download a program into the
5076 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5077 also supports debugging of realtime processes running under VxWorks,
5078 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5079 stub on the target system.
5081 New CPUs supported include the AMD 29000 and Intel 960.
5083 GDB now reads object files and symbol tables via a ``binary file''
5084 library, which allows a single copy of GDB to debug programs of multiple
5085 object file types such as a.out and coff.
5087 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5088 refcard.dvi and refcard.ps are available to format it).
5091 * Control-Variable user interface simplified
5093 All variables that control the operation of the debugger can be set
5094 by the ``set'' command, and displayed by the ``show'' command.
5096 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5097 ``Show prompt'' produces the response:
5098 Gdb's prompt is new-gdb=>.
5100 What follows are the NEW set commands. The command ``help set'' will
5101 print a complete list of old and new set commands. ``help set FOO''
5102 will give a longer description of the variable FOO. ``show'' will show
5103 all of the variable descriptions and their current settings.
5105 confirm on/off: Enables warning questions for operations that are
5106 hard to recover from, e.g. rerunning the program while
5107 it is already running. Default is ON.
5109 editing on/off: Enables EMACS style command line editing
5110 of input. Previous lines can be recalled with
5111 control-P, the current line can be edited with control-B,
5112 you can search for commands with control-R, etc.
5115 history filename NAME: NAME is where the gdb command history
5116 will be stored. The default is .gdb_history,
5117 or the value of the environment variable
5120 history size N: The size, in commands, of the command history. The
5121 default is 256, or the value of the environment variable
5124 history save on/off: If this value is set to ON, the history file will
5125 be saved after exiting gdb. If set to OFF, the
5126 file will not be saved. The default is OFF.
5128 history expansion on/off: If this value is set to ON, then csh-like
5129 history expansion will be performed on
5130 command line input. The default is OFF.
5132 radix N: Sets the default radix for input and output. It can be set
5133 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5134 in the current radix, so "set radix 10" is always a no-op.
5136 height N: This integer value is the number of lines on a page. Default
5137 is 24, the current `stty rows'' setting, or the ``li#''
5138 setting from the termcap entry matching the environment
5141 width N: This integer value is the number of characters on a line.
5142 Default is 80, the current `stty cols'' setting, or the ``co#''
5143 setting from the termcap entry matching the environment
5146 Note: ``set screensize'' is obsolete. Use ``set height'' and
5147 ``set width'' instead.
5149 print address on/off: Print memory addresses in various command displays,
5150 such as stack traces and structure values. Gdb looks
5151 more ``symbolic'' if you turn this off; it looks more
5152 ``machine level'' with it on. Default is ON.
5154 print array on/off: Prettyprint arrays. New convenient format! Default
5157 print demangle on/off: Print C++ symbols in "source" form if on,
5160 print asm-demangle on/off: Same, for assembler level printouts
5163 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5166 * Support for Epoch Environment.
5168 The epoch environment is a version of Emacs v18 with windowing. One
5169 new command, ``inspect'', is identical to ``print'', except that if you
5170 are running in the epoch environment, the value is printed in its own
5174 * Support for Shared Libraries
5176 GDB can now debug programs and core files that use SunOS shared libraries.
5177 Symbols from a shared library cannot be referenced
5178 before the shared library has been linked with the program (this
5179 happens after you type ``run'' and before the function main() is entered).
5180 At any time after this linking (including when examining core files
5181 from dynamically linked programs), gdb reads the symbols from each
5182 shared library when you type the ``sharedlibrary'' command.
5183 It can be abbreviated ``share''.
5185 sharedlibrary REGEXP: Load shared object library symbols for files
5186 matching a unix regular expression. No argument
5187 indicates to load symbols for all shared libraries.
5189 info sharedlibrary: Status of loaded shared libraries.
5194 A watchpoint stops execution of a program whenever the value of an
5195 expression changes. Checking for this slows down execution
5196 tremendously whenever you are in the scope of the expression, but is
5197 quite useful for catching tough ``bit-spreader'' or pointer misuse
5198 problems. Some machines such as the 386 have hardware for doing this
5199 more quickly, and future versions of gdb will use this hardware.
5201 watch EXP: Set a watchpoint (breakpoint) for an expression.
5203 info watchpoints: Information about your watchpoints.
5205 delete N: Deletes watchpoint number N (same as breakpoints).
5206 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5207 enable N: Re-enables watchpoint number N (same as breakpoints).
5210 * C++ multiple inheritance
5212 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5215 * C++ exception handling
5217 Gdb now supports limited C++ exception handling. Besides the existing
5218 ability to breakpoint on an exception handler, gdb can breakpoint on
5219 the raising of an exception (before the stack is peeled back to the
5222 catch FOO: If there is a FOO exception handler in the dynamic scope,
5223 set a breakpoint to catch exceptions which may be raised there.
5224 Multiple exceptions (``catch foo bar baz'') may be caught.
5226 info catch: Lists all exceptions which may be caught in the
5227 current stack frame.
5230 * Minor command changes
5232 The command ``call func (arg, arg, ...)'' now acts like the print
5233 command, except it does not print or save a value if the function's result
5234 is void. This is similar to dbx usage.
5236 The ``up'' and ``down'' commands now always print the frame they end up
5237 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5238 frames without printing.
5240 * New directory command
5242 'dir' now adds directories to the FRONT of the source search path.
5243 The path starts off empty. Source files that contain debug information
5244 about the directory in which they were compiled can be found even
5245 with an empty path; Sun CC and GCC include this information. If GDB can't
5246 find your source file in the current directory, type "dir .".
5248 * Configuring GDB for compilation
5250 For normal use, type ``./configure host''. See README or gdb.texinfo
5253 GDB now handles cross debugging. If you are remotely debugging between
5254 two different machines, type ``./configure host -target=targ''.
5255 Host is the machine where GDB will run; targ is the machine
5256 where the program that you are debugging will run.