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
17 * If the configured location of system.gdbinit file (as given by the
18 --with-system-gdbinit option at configure time) is in the
19 data-directory (as specified by --with-gdb-datadir at configure
20 time) or in one of its subdirectories, then GDB will look for the
21 system-wide init file in the directory specified by the
22 --data-directory command-line option.
24 * New command line options:
26 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
27 other initialization files, unlike -nx which disables all of them.
29 * Removed command line options
31 -epoch This was used by the gdb mode in Epoch, an ancient fork of
34 * The 'ptype' and 'whatis' commands now accept an argument to control
37 * 'info proc' now works on some core files.
41 ** Vectors can be created with gdb.Type.vector.
43 ** Python's atexit.register now works in GDB.
45 ** Types can be pretty-printed via a Python API.
47 ** Python 3 is now supported (in addition to Python 2.4 or later)
49 ** New class gdb.Architecture exposes GDB's internal representation
50 of architecture in the Python API.
52 ** New method Frame.architecture returns the gdb.Architecture object
53 corresponding to the frame's architecture.
55 * New Python-based convenience functions:
57 ** $_memeq(buf1, buf2, length)
58 ** $_streq(str1, str2)
60 ** $_regex(str, regex)
62 * The 'cd' command now defaults to using '~' (the home directory) if not
65 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
66 default for GCC since November 2000.
68 * The command 'forward-search' can now be abbreviated as 'fo'.
70 * The command 'info tracepoints' can now display 'installed on target'
71 or 'not installed on target' for each non-pending location of tracepoint.
73 * New configure options
75 --enable-libmcheck/--disable-libmcheck
76 By default, development versions are built with -lmcheck on hosts
77 that support it, in order to help track memory corruption issues.
78 Release versions, on the other hand, are built without -lmcheck
79 by default. The --enable-libmcheck/--disable-libmcheck configure
80 options allow the user to override that default.
82 * New commands (for set/show, see "New options" below)
85 Catch signals. This is similar to "handle", but allows commands and
86 conditions to be attached.
89 List the BFDs known to GDB.
91 python-interactive [command]
93 Start a Python interactive prompt, or evaluate the optional command
94 and print the result of expressions.
97 "py" is a new alias for "python".
99 enable type-printer [name]...
100 disable type-printer [name]...
101 Enable or disable type printers.
103 set debug notification
104 show debug notification
105 Control display of debugging info for async remote notification.
109 ** For the Renesas Super-H architecture, the "regs" command has been removed
110 (has been deprecated in GDB 7.5), and "info all-registers" should be used
115 set print type methods (on|off)
116 show print type methods
117 Control whether method declarations are displayed by "ptype".
118 The default is to show them.
120 set print type typedefs (on|off)
121 show print type typedefs
122 Control whether typedef definitions are displayed by "ptype".
123 The default is to show them.
125 set filename-display basename|relative|absolute
126 show filename-display
127 Control the way in which filenames is displayed.
128 The default is "relative", which preserves previous behavior.
132 ** Command parameter changes are now notified using new async record
133 "=cmd-param-changed".
134 ** Trace frame changes caused by command "tfind" are now notified using
135 new async record "=traceframe-changed".
136 ** The creation, deletion and modification of trace state variables
137 are now notified using new async records "=tsv-created",
138 "=tsv-deleted" and "=tsv-modified".
139 ** The start and stop of process record are now notified using new
140 async record "=record-started" and "=record-stopped".
141 ** Memory changes are now notified using new async record
143 ** The data-disassemble command response will include a "fullname" field
144 containing the absolute file name when GDB can determine it and source
146 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
147 command, to allow pattern filling of memory areas.
148 ** New commands "-catch-load"/"-catch-unload" added for intercepting
149 library load/unload events.
150 ** The response to breakpoint commands and breakpoint async records
151 includes an "installed" field containing a boolean state about each
152 non-pending tracepoint location is whether installed on target or not.
154 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
155 You must have the LZMA library available when configuring GDB for this
156 feature to be enabled. For more information, see:
157 http://fedoraproject.org/wiki/Features/MiniDebugInfo
159 *** Changes in GDB 7.5
161 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
162 for more x32 ABI info.
164 * GDB now supports access to MIPS DSP registers on Linux targets.
166 * GDB now supports debugging microMIPS binaries.
168 * The "info os" command on GNU/Linux can now display information on
169 several new classes of objects managed by the operating system:
170 "info os procgroups" lists process groups
171 "info os files" lists file descriptors
172 "info os sockets" lists internet-domain sockets
173 "info os shm" lists shared-memory regions
174 "info os semaphores" lists semaphores
175 "info os msg" lists message queues
176 "info os modules" lists loaded kernel modules
178 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
179 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
180 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
181 options and inspect the probe arguments using the new $_probe_arg family
182 of convenience variables. You can obtain more information about SystemTap
183 in <http://sourceware.org/systemtap/>.
185 * GDB now supports reversible debugging on ARM, it allows you to
186 debug basic ARM and THUMB instructions, and provides
187 record/replay support.
189 * The option "symbol-reloading" has been deleted as it is no longer used.
193 ** GDB commands implemented in Python can now be put in command class
196 ** The "maint set python print-stack on|off" is now deleted.
198 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
199 apply "flag enum"-style pretty-printing to any enum.
201 ** gdb.lookup_symbol can now work when there is no current frame.
203 ** gdb.Symbol now has a 'line' attribute, holding the line number in
204 the source at which the symbol was defined.
206 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
207 method 'value'. The former indicates whether the symbol needs a
208 frame in order to compute its value, and the latter computes the
211 ** A new method 'referenced_value' on gdb.Value objects which can
212 dereference pointer as well as C++ reference values.
214 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
215 which return the global and static blocks (as gdb.Block objects),
216 of the underlying symbol table, respectively.
218 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
219 object associated with a PC value.
221 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
222 of the address range occupied by code for the current source line.
224 * Go language support.
225 GDB now supports debugging programs written in the Go programming
228 * GDBserver now supports stdio connections.
229 E.g. (gdb) target remote | ssh myhost gdbserver - hello
231 * The binary "gdbtui" can no longer be built or installed.
232 Use "gdb -tui" instead.
234 * GDB will now print "flag" enums specially. A flag enum is one where
235 all the enumerator values have no bits in common when pairwise
236 "and"ed. When printing a value whose type is a flag enum, GDB will
237 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
238 (gdb) print (enum E) 3
241 * The filename part of a linespec will now match trailing components
242 of a source file name. For example, "break gcc/expr.c:1000" will
243 now set a breakpoint in build/gcc/expr.c, but not
246 * The "info proc" and "generate-core-file" commands will now also
247 work on remote targets connected to GDBserver on Linux.
249 * The command "info catch" has been removed. It has been disabled
252 * The "catch exception" and "catch assert" commands now accept
253 a condition at the end of the command, much like the "break"
254 command does. For instance:
256 (gdb) catch exception Constraint_Error if Barrier = True
258 Previously, it was possible to add a condition to such catchpoints,
259 but it had to be done as a second step, after the catchpoint had been
260 created, using the "condition" command.
262 * The "info static-tracepoint-marker" command will now also work on
263 native Linux targets with in-process agent.
265 * GDB can now set breakpoints on inlined functions.
267 * The .gdb_index section has been updated to include symbols for
268 inlined functions. GDB will ignore older .gdb_index sections by
269 default, which could cause symbol files to be loaded more slowly
270 until their .gdb_index sections can be recreated. The new command
271 "set use-deprecated-index-sections on" will cause GDB to use any older
272 .gdb_index sections it finds. This will restore performance, but the
273 ability to set breakpoints on inlined functions will be lost in symbol
274 files with older .gdb_index sections.
276 The .gdb_index section has also been updated to record more information
277 about each symbol. This speeds up the "info variables", "info functions"
278 and "info types" commands when used with programs having the .gdb_index
279 section, as well as speeding up debugging with shared libraries using
280 the .gdb_index section.
282 * Ada support for GDB/MI Variable Objects has been added.
284 * GDB can now support 'breakpoint always-inserted mode' in 'record'
289 ** New command -info-os is the MI equivalent of "info os".
291 ** Output logs ("set logging" and related) now include MI output.
295 ** "set use-deprecated-index-sections on|off"
296 "show use-deprecated-index-sections on|off"
297 Controls the use of deprecated .gdb_index sections.
299 ** "catch load" and "catch unload" can be used to stop when a shared
300 library is loaded or unloaded, respectively.
302 ** "enable count" can be used to auto-disable a breakpoint after
305 ** "info vtbl" can be used to show the virtual method tables for
306 C++ and Java objects.
308 ** "explore" and its sub commands "explore value" and "explore type"
309 can be used to reccursively explore values and types of
310 expressions. These commands are available only if GDB is
311 configured with '--with-python'.
313 ** "info auto-load" shows status of all kinds of auto-loaded files,
314 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
315 sequences of commands files, "info auto-load python-scripts"
316 shows status of auto-loading Python script files,
317 "info auto-load local-gdbinit" shows status of loading init file
318 (.gdbinit) from current directory and "info auto-load libthread-db" shows
319 status of inferior specific thread debugging shared library loading.
321 ** "info auto-load-scripts", "set auto-load-scripts on|off"
322 and "show auto-load-scripts" commands have been deprecated, use their
323 "info auto-load python-scripts", "set auto-load python-scripts on|off"
324 and "show auto-load python-scripts" counterparts instead.
326 ** "dprintf location,format,args..." creates a dynamic printf, which
327 is basically a breakpoint that does a printf and immediately
328 resumes your program's execution, so it is like a printf that you
329 can insert dynamically at runtime instead of at compiletime.
331 ** "set print symbol"
333 Controls whether GDB attempts to display the symbol, if any,
334 corresponding to addresses it prints. This defaults to "on", but
335 you can set it to "off" to restore GDB's previous behavior.
337 * Deprecated commands
339 ** For the Renesas Super-H architecture, the "regs" command has been
340 deprecated, and "info all-registers" should be used instead.
344 Renesas RL78 rl78-*-elf
345 HP OpenVMS ia64 ia64-hp-openvms*
347 * GDBserver supports evaluation of breakpoint conditions. When
348 support is advertised by GDBserver, GDB may be told to send the
349 breakpoint conditions in bytecode form to GDBserver. GDBserver
350 will only report the breakpoint trigger to GDB when its condition
356 show mips compression
357 Select the compressed ISA encoding used in functions that have no symbol
358 information available. The encoding can be set to either of:
361 and is updated automatically from ELF file flags if available.
363 set breakpoint condition-evaluation
364 show breakpoint condition-evaluation
365 Control whether breakpoint conditions are evaluated by GDB ("host") or by
366 GDBserver ("target"). Default option "auto" chooses the most efficient
368 This option can improve debugger efficiency depending on the speed of the
372 Disable auto-loading globally.
375 Show auto-loading setting of all kinds of auto-loaded files.
377 set auto-load gdb-scripts on|off
378 show auto-load gdb-scripts
379 Control auto-loading of GDB canned sequences of commands files.
381 set auto-load python-scripts on|off
382 show auto-load python-scripts
383 Control auto-loading of Python script files.
385 set auto-load local-gdbinit on|off
386 show auto-load local-gdbinit
387 Control loading of init file (.gdbinit) from current directory.
389 set auto-load libthread-db on|off
390 show auto-load libthread-db
391 Control auto-loading of inferior specific thread debugging shared library.
393 set auto-load scripts-directory <dir1>[:<dir2>...]
394 show auto-load scripts-directory
395 Set a list of directories from which to load auto-loaded scripts.
396 Automatically loaded Python scripts and GDB scripts are located in one
397 of the directories listed by this option.
398 The delimiter (':' above) may differ according to the host platform.
400 set auto-load safe-path <dir1>[:<dir2>...]
401 show auto-load safe-path
402 Set a list of directories from which it is safe to auto-load files.
403 The delimiter (':' above) may differ according to the host platform.
405 set debug auto-load on|off
407 Control display of debugging info for auto-loading the files above.
409 set dprintf-style gdb|call|agent
411 Control the way in which a dynamic printf is performed; "gdb"
412 requests a GDB printf command, while "call" causes dprintf to call a
413 function in the inferior. "agent" requests that the target agent
414 (such as GDBserver) do the printing.
416 set dprintf-function <expr>
417 show dprintf-function
418 set dprintf-channel <expr>
420 Set the function and optional first argument to the call when using
421 the "call" style of dynamic printf.
423 set disconnected-dprintf on|off
424 show disconnected-dprintf
425 Control whether agent-style dynamic printfs continue to be in effect
426 after GDB disconnects.
428 * New configure options
431 Configure default value for the 'set auto-load scripts-directory'
432 setting above. It defaults to '$debugdir:$datadir/auto-load',
433 $debugdir representing global debugging info directories (available
434 via 'show debug-file-directory') and $datadir representing GDB's data
435 directory (available via 'show data-directory').
437 --with-auto-load-safe-path
438 Configure default value for the 'set auto-load safe-path' setting
439 above. It defaults to the --with-auto-load-dir setting.
441 --without-auto-load-safe-path
442 Set 'set auto-load safe-path' to '/', effectively disabling this
447 z0/z1 conditional breakpoints extension
449 The z0/z1 breakpoint insertion packets have been extended to carry
450 a list of conditional expressions over to the remote stub depending on the
451 condition evaluation mode. The use of this extension can be controlled
452 via the "set remote conditional-breakpoints-packet" command.
456 Specify the signals which the remote stub may pass to the debugged
457 program without GDB involvement.
459 * New command line options
461 --init-command=FILE, -ix Like --command, -x but execute it
462 before loading inferior.
463 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
464 execute it before loading inferior.
466 *** Changes in GDB 7.4
468 * GDB now handles ambiguous linespecs more consistently; the existing
469 FILE:LINE support has been expanded to other types of linespecs. A
470 breakpoint will now be set on all matching locations in all
471 inferiors, and locations will be added or removed according to
474 * GDB now allows you to skip uninteresting functions and files when
475 stepping with the "skip function" and "skip file" commands.
477 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
478 and "show remote hardware-watchpoint-length-limit". These allows to
479 set or show the maximum length limit (in bytes) of a remote
480 target hardware watchpoint.
482 This allows e.g. to use "unlimited" hardware watchpoints with the
483 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
484 watchpoints are slower than real hardware watchpoints but are
485 significantly faster than gdb software watchpoints.
489 ** The register_pretty_printer function in module gdb.printing now takes
490 an optional `replace' argument. If True, the new printer replaces any
493 ** The "maint set python print-stack on|off" command has been
494 deprecated and will be deleted in GDB 7.5.
495 A new command: "set python print-stack none|full|message" has
496 replaced it. Additionally, the default for "print-stack" is
497 now "message", which just prints the error message without
500 ** A prompt substitution hook (prompt_hook) is now available to the
503 ** A new Python module, gdb.prompt has been added to the GDB Python
504 modules library. This module provides functionality for
505 escape sequences in prompts (used by set/show
506 extended-prompt). These escape sequences are replaced by their
509 ** Python commands and convenience-functions located in
510 'data-directory'/python/gdb/command and
511 'data-directory'/python/gdb/function are now automatically loaded
514 ** Blocks now provide four new attributes. global_block and
515 static_block will return the global and static blocks
516 respectively. is_static and is_global are boolean attributes
517 that indicate if the block is one of those two types.
519 ** Symbols now provide the "type" attribute, the type of the symbol.
521 ** The "gdb.breakpoint" function has been deprecated in favor of
524 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
525 of a function. This class is based on the "finish" command
526 available in the CLI.
528 ** Type objects for struct and union types now allow access to
529 the fields using standard Python dictionary (mapping) methods.
530 For example, "some_type['myfield']" now works, as does
533 ** A new event "gdb.new_objfile" has been added, triggered by loading a
536 ** A new function, "deep_items" has been added to the gdb.types
537 module in the GDB Python modules library. This function returns
538 an iterator over the fields of a struct or union type. Unlike
539 the standard Python "iteritems" method, it will recursively traverse
540 any anonymous fields.
544 ** "*stopped" events can report several new "reason"s, such as
547 ** Breakpoint changes are now notified using new async records, like
548 "=breakpoint-modified".
550 ** New command -ada-task-info.
552 * libthread-db-search-path now supports two special values: $sdir and $pdir.
553 $sdir specifies the default system locations of shared libraries.
554 $pdir specifies the directory where the libpthread used by the application
557 GDB no longer looks in $sdir and $pdir after it has searched the directories
558 mentioned in libthread-db-search-path. If you want to search those
559 directories, they must be specified in libthread-db-search-path.
560 The default value of libthread-db-search-path on GNU/Linux and Solaris
561 systems is now "$sdir:$pdir".
563 $pdir is not supported by gdbserver, it is currently ignored.
564 $sdir is supported by gdbserver.
566 * New configure option --with-iconv-bin.
567 When using the internationalization support like the one in the GNU C
568 library, GDB will invoke the "iconv" program to get a list of supported
569 character sets. If this program lives in a non-standard location, one can
570 use this option to specify where to find it.
572 * When natively debugging programs on PowerPC BookE processors running
573 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
574 watchpoints, which specify a mask in addition to an address to watch.
575 The mask specifies that some bits of an address (the bits which are
576 reset in the mask) should be ignored when matching the address accessed
577 by the inferior against the watchpoint address. See the "PowerPC Embedded"
578 section in the user manual for more details.
580 * The new option --once causes GDBserver to stop listening for connections once
581 the first connection is made. The listening port used by GDBserver will
582 become available after that.
584 * New commands "info macros" and "alias" have been added.
586 * New function parameters suffix @entry specifies value of function parameter
587 at the time the function got called. Entry values are available only since
593 "!" is now an alias of the "shell" command.
594 Note that no space is needed between "!" and SHELL COMMAND.
598 watch EXPRESSION mask MASK_VALUE
599 The watch command now supports the mask argument which allows creation
600 of masked watchpoints, if the current architecture supports this feature.
602 info auto-load-scripts [REGEXP]
603 This command was formerly named "maintenance print section-scripts".
604 It is now generally useful and is no longer a maintenance-only command.
606 info macro [-all] [--] MACRO
607 The info macro command has new options `-all' and `--'. The first for
608 printing all definitions of a macro. The second for explicitly specifying
609 the end of arguments and the beginning of the macro name in case the macro
610 name starts with a hyphen.
612 collect[/s] EXPRESSIONS
613 The tracepoint collect command now takes an optional modifier "/s"
614 that directs it to dereference pointer-to-character types and
615 collect the bytes of memory up to a zero byte. The behavior is
616 similar to what you see when you use the regular print command on a
617 string. An optional integer following the "/s" sets a bound on the
618 number of bytes that will be collected.
621 The trace start command now interprets any supplied arguments as a
622 note to be recorded with the trace run, with an effect similar to
623 setting the variable trace-notes.
626 The trace stop command now interprets any arguments as a note to be
627 mentioned along with the tstatus report that the trace was stopped
628 with a command. The effect is similar to setting the variable
631 * Tracepoints can now be enabled and disabled at any time after a trace
632 experiment has been started using the standard "enable" and "disable"
633 commands. It is now possible to start a trace experiment with no enabled
634 tracepoints; GDB will display a warning, but will allow the experiment to
635 begin, assuming that tracepoints will be enabled as needed while the trace
638 * Fast tracepoints on 32-bit x86-architectures can now be placed at
639 locations with 4-byte instructions, when they were previously
640 limited to locations with instructions of 5 bytes or longer.
644 set debug dwarf2-read
645 show debug dwarf2-read
646 Turns on or off display of debugging messages related to reading
647 DWARF debug info. The default is off.
649 set debug symtab-create
650 show debug symtab-create
651 Turns on or off display of debugging messages related to symbol table
652 creation. The default is off.
656 Set the GDB prompt, and allow escape sequences to be inserted to
657 display miscellaneous information (see 'help set extended-prompt'
658 for the list of sequences). This prompt (and any information
659 accessed through the escape sequences) is updated every time the
662 set print entry-values (both|compact|default|if-needed|no|only|preferred)
663 show print entry-values
664 Set printing of frame argument values at function entry. In some cases
665 GDB can determine the value of function argument which was passed by the
666 function caller, even if the value was modified inside the called function.
668 set debug entry-values
669 show debug entry-values
670 Control display of debugging info for determining frame argument values at
671 function entry and virtual tail call frames.
673 set basenames-may-differ
674 show basenames-may-differ
675 Set whether a source file may have multiple base names.
676 (A "base name" is the name of a file with the directory part removed.
677 Example: The base name of "/home/user/hello.c" is "hello.c".)
678 If set, GDB will canonicalize file names (e.g., expand symlinks)
679 before comparing them. Canonicalization is an expensive operation,
680 but it allows the same file be known by more than one base name.
681 If not set (the default), all source files are assumed to have just
682 one base name, and gdb will do file name comparisons more efficiently.
688 Set a user name and notes for the current and any future trace runs.
689 This is useful for long-running and/or disconnected traces, to
690 inform others (or yourself) as to who is running the trace, supply
691 contact information, or otherwise explain what is going on.
694 show trace-stop-notes
695 Set a note attached to the trace run, that is displayed when the
696 trace has been stopped by a tstop command. This is useful for
697 instance as an explanation, if you are stopping a trace run that was
698 started by someone else.
704 Dynamically enable a tracepoint in a started trace experiment.
708 Dynamically disable a tracepoint in a started trace experiment.
712 Set the user and notes of the trace run.
716 Query the current status of a tracepoint.
720 Query the minimum length of instruction at which a fast tracepoint may
723 * Dcache size (number of lines) and line-size are now runtime-configurable
724 via "set dcache line" and "set dcache line-size" commands.
728 Texas Instruments TMS320C6x tic6x-*-*
732 Renesas RL78 rl78-*-elf
734 *** Changes in GDB 7.3.1
736 * The build failure for NetBSD and OpenBSD targets have now been fixed.
738 *** Changes in GDB 7.3
740 * GDB has a new command: "thread find [REGEXP]".
741 It finds the thread id whose name, target id, or thread extra info
742 matches the given regular expression.
744 * The "catch syscall" command now works on mips*-linux* targets.
746 * The -data-disassemble MI command now supports modes 2 and 3 for
747 dumping the instruction opcodes.
749 * New command line options
751 -data-directory DIR Specify DIR as the "data-directory".
752 This is mostly for testing purposes.
754 * The "maint set python auto-load on|off" command has been renamed to
755 "set auto-load-scripts on|off".
757 * GDB has a new command: "set directories".
758 It is like the "dir" command except that it replaces the
759 source path list instead of augmenting it.
761 * GDB now understands thread names.
763 On GNU/Linux, "info threads" will display the thread name as set by
764 prctl or pthread_setname_np.
766 There is also a new command, "thread name", which can be used to
767 assign a name internally for GDB to display.
770 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
771 has been integrated into GDB.
775 ** The function gdb.Write now accepts an optional keyword 'stream'.
776 This keyword, when provided, will direct the output to either
777 stdout, stderr, or GDB's logging output.
779 ** Parameters can now be be sub-classed in Python, and in particular
780 you may implement the get_set_doc and get_show_doc functions.
781 This improves how Parameter set/show documentation is processed
782 and allows for more dynamic content.
784 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
785 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
786 have an is_valid method.
788 ** Breakpoints can now be sub-classed in Python, and in particular
789 you may implement a 'stop' function that is executed each time
790 the inferior reaches that breakpoint.
792 ** New function gdb.lookup_global_symbol looks up a global symbol.
794 ** GDB values in Python are now callable if the value represents a
795 function. For example, if 'some_value' represents a function that
796 takes two integer parameters and returns a value, you can call
797 that function like so:
799 result = some_value (10,20)
801 ** Module gdb.types has been added.
802 It contains a collection of utilities for working with gdb.Types objects:
803 get_basic_type, has_field, make_enum_dict.
805 ** Module gdb.printing has been added.
806 It contains utilities for writing and registering pretty-printers.
807 New classes: PrettyPrinter, SubPrettyPrinter,
808 RegexpCollectionPrettyPrinter.
809 New function: register_pretty_printer.
811 ** New commands "info pretty-printers", "enable pretty-printer" and
812 "disable pretty-printer" have been added.
814 ** gdb.parameter("directories") is now available.
816 ** New function gdb.newest_frame returns the newest frame in the
819 ** The gdb.InferiorThread class has a new "name" attribute. This
820 holds the thread's name.
822 ** Python Support for Inferior events.
823 Python scripts can add observers to be notified of events
824 occurring in the process being debugged.
825 The following events are currently supported:
826 - gdb.events.cont Continue event.
827 - gdb.events.exited Inferior exited event.
828 - gdb.events.stop Signal received, and Breakpoint hit events.
832 ** GDB now puts template parameters in scope when debugging in an
833 instantiation. For example, if you have:
835 template<int X> int func (void) { return X; }
837 then if you step into func<5>, "print X" will show "5". This
838 feature requires proper debuginfo support from the compiler; it
839 was added to GCC 4.5.
841 ** The motion commands "next", "finish", "until", and "advance" now
842 work better when exceptions are thrown. In particular, GDB will
843 no longer lose control of the inferior; instead, the GDB will
844 stop the inferior at the point at which the exception is caught.
845 This functionality requires a change in the exception handling
846 code that was introduced in GCC 4.5.
848 * GDB now follows GCC's rules on accessing volatile objects when
849 reading or writing target state during expression evaluation.
850 One notable difference to prior behavior is that "print x = 0"
851 no longer generates a read of x; the value of the assignment is
852 now always taken directly from the value being assigned.
854 * GDB now has some support for using labels in the program's source in
855 linespecs. For instance, you can use "advance label" to continue
856 execution to a label.
858 * GDB now has support for reading and writing a new .gdb_index
859 section. This section holds a fast index of DWARF debugging
860 information and can be used to greatly speed up GDB startup and
861 operation. See the documentation for `save gdb-index' for details.
863 * The "watch" command now accepts an optional "-location" argument.
864 When used, this causes GDB to watch the memory referred to by the
865 expression. Such a watchpoint is never deleted due to it going out
868 * GDB now supports thread debugging of core dumps on GNU/Linux.
870 GDB now activates thread debugging using the libthread_db library
871 when debugging GNU/Linux core dumps, similarly to when debugging
872 live processes. As a result, when debugging a core dump file, GDB
873 is now able to display pthread_t ids of threads. For example, "info
874 threads" shows the same output as when debugging the process when it
875 was live. In earlier releases, you'd see something like this:
878 * 1 LWP 6780 main () at main.c:10
880 While now you see this:
883 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
885 It is also now possible to inspect TLS variables when debugging core
888 When debugging a core dump generated on a machine other than the one
889 used to run GDB, you may need to point GDB at the correct
890 libthread_db library with the "set libthread-db-search-path"
891 command. See the user manual for more details on this command.
893 * When natively debugging programs on PowerPC BookE processors running
894 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
895 which stop execution of the inferior whenever it executes an instruction
896 at any address within the specified range. See the "PowerPC Embedded"
897 section in the user manual for more details.
899 * New features in the GDB remote stub, GDBserver
901 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
902 and i686 LynxOS (version 5.x).
904 ** GDBserver is now supported on Blackfin Linux.
906 * New native configurations
908 ia64 HP-UX ia64-*-hpux*
912 Analog Devices, Inc. Blackfin Processor bfin-*
914 * Ada task switching is now supported on sparc-elf targets when
915 debugging a program using the Ravenscar Profile. For more information,
916 see the "Tasking Support when using the Ravenscar Profile" section
917 in the GDB user manual.
919 * Guile support was removed.
921 * New features in the GNU simulator
923 ** The --map-info flag lists all known core mappings.
925 ** CFI flashes may be simulated via the "cfi" device.
927 *** Changes in GDB 7.2
929 * Shared library support for remote targets by default
931 When GDB is configured for a generic, non-OS specific target, like
932 for example, --target=arm-eabi or one of the many *-*-elf targets,
933 GDB now queries remote stubs for loaded shared libraries using the
934 `qXfer:libraries:read' packet. Previously, shared library support
935 was always disabled for such configurations.
939 ** Argument Dependent Lookup (ADL)
941 In C++ ADL lookup directs function search to the namespaces of its
942 arguments even if the namespace has not been imported.
952 Here the compiler will search for `foo' in the namespace of 'b'
953 and find A::foo. GDB now supports this. This construct is commonly
954 used in the Standard Template Library for operators.
956 ** Improved User Defined Operator Support
958 In addition to member operators, GDB now supports lookup of operators
959 defined in a namespace and imported with a `using' directive, operators
960 defined in the global scope, operators imported implicitly from an
961 anonymous namespace, and the ADL operators mentioned in the previous
963 GDB now also supports proper overload resolution for all the previously
964 mentioned flavors of operators.
966 ** static const class members
968 Printing of static const class members that are initialized in the
969 class definition has been fixed.
971 * Windows Thread Information Block access.
973 On Windows targets, GDB now supports displaying the Windows Thread
974 Information Block (TIB) structure. This structure is visible either
975 by using the new command `info w32 thread-information-block' or, by
976 dereferencing the new convenience variable named `$_tlb', a
977 thread-specific pointer to the TIB. This feature is also supported
978 when remote debugging using GDBserver.
982 Static tracepoints are calls in the user program into a tracing
983 library. One such library is a port of the LTTng kernel tracer to
984 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
985 When debugging with GDBserver, GDB now supports combining the GDB
986 tracepoint machinery with such libraries. For example: the user can
987 use GDB to probe a static tracepoint marker (a call from the user
988 program into the tracing library) with the new "strace" command (see
989 "New commands" below). This creates a "static tracepoint" in the
990 breakpoint list, that can be manipulated with the same feature set
991 as fast and regular tracepoints. E.g., collect registers, local and
992 global variables, collect trace state variables, and define
993 tracepoint conditions. In addition, the user can collect extra
994 static tracepoint marker specific data, by collecting the new
995 $_sdata internal variable. When analyzing the trace buffer, you can
996 inspect $_sdata like any other variable available to GDB. For more
997 information, see the "Tracepoints" chapter in GDB user manual. New
998 remote packets have been defined to support static tracepoints, see
999 the "New remote packets" section below.
1001 * Better reconstruction of tracepoints after disconnected tracing
1003 GDB will attempt to download the original source form of tracepoint
1004 definitions when starting a trace run, and then will upload these
1005 upon reconnection to the target, resulting in a more accurate
1006 reconstruction of the tracepoints that are in use on the target.
1010 You can now exercise direct control over the ways that GDB can
1011 affect your program. For instance, you can disallow the setting of
1012 breakpoints, so that the program can run continuously (assuming
1013 non-stop mode). In addition, the "observer" variable is available
1014 to switch all of the different controls; in observer mode, GDB
1015 cannot affect the target's behavior at all, which is useful for
1016 tasks like diagnosing live systems in the field.
1018 * The new convenience variable $_thread holds the number of the
1021 * New remote packets
1025 Return the address of the Windows Thread Information Block of a given thread.
1029 In response to several of the tracepoint packets, the target may now
1030 also respond with a number of intermediate `qRelocInsn' request
1031 packets before the final result packet, to have GDB handle
1032 relocating an instruction to execute at a different address. This
1033 is particularly useful for stubs that support fast tracepoints. GDB
1034 reports support for this feature in the qSupported packet.
1038 List static tracepoint markers in the target program.
1042 List static tracepoint markers at a given address in the target
1045 qXfer:statictrace:read
1047 Read the static trace data collected (by a `collect $_sdata'
1048 tracepoint action). The remote stub reports support for this packet
1049 to gdb's qSupported query.
1053 Send the current settings of GDB's permission flags.
1057 Send part of the source (textual) form of a tracepoint definition,
1058 which includes location, conditional, and action list.
1060 * The source command now accepts a -s option to force searching for the
1061 script in the source search path even if the script name specifies
1064 * New features in the GDB remote stub, GDBserver
1066 - GDBserver now support tracepoints (including fast tracepoints, and
1067 static tracepoints). The feature is currently supported by the
1068 i386-linux and amd64-linux builds. See the "Tracepoints support
1069 in gdbserver" section in the manual for more information.
1071 GDBserver JIT compiles the tracepoint's conditional agent
1072 expression bytecode into native code whenever possible for low
1073 overhead dynamic tracepoints conditionals. For such tracepoints,
1074 an expression that examines program state is evaluated when the
1075 tracepoint is reached, in order to determine whether to capture
1076 trace data. If the condition is simple and false, processing the
1077 tracepoint finishes very quickly and no data is gathered.
1079 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1080 for static tracepoints support.
1082 - GDBserver now supports x86_64 Windows 64-bit debugging.
1084 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1085 it understands register description.
1087 * The --batch flag now disables pagination and queries.
1089 * X86 general purpose registers
1091 GDB now supports reading/writing byte, word and double-word x86
1092 general purpose registers directly. This means you can use, say,
1093 $ah or $ax to refer, respectively, to the byte register AH and
1094 16-bit word register AX that are actually portions of the 32-bit
1095 register EAX or 64-bit register RAX.
1097 * The `commands' command now accepts a range of breakpoints to modify.
1098 A plain `commands' following a command that creates multiple
1099 breakpoints affects all the breakpoints set by that command. This
1100 applies to breakpoints set by `rbreak', and also applies when a
1101 single `break' command creates multiple breakpoints (e.g.,
1102 breakpoints on overloaded c++ functions).
1104 * The `rbreak' command now accepts a filename specification as part of
1105 its argument, limiting the functions selected by the regex to those
1106 in the specified file.
1108 * Support for remote debugging Windows and SymbianOS shared libraries
1109 from Unix hosts has been improved. Non Windows GDB builds now can
1110 understand target reported file names that follow MS-DOS based file
1111 system semantics, such as file names that include drive letters and
1112 use the backslash character as directory separator. This makes it
1113 possible to transparently use the "set sysroot" and "set
1114 solib-search-path" on Unix hosts to point as host copies of the
1115 target's shared libraries. See the new command "set
1116 target-file-system-kind" described below, and the "Commands to
1117 specify files" section in the user manual for more information.
1121 eval template, expressions...
1122 Convert the values of one or more expressions under the control
1123 of the string template to a command line, and call it.
1125 set target-file-system-kind unix|dos-based|auto
1126 show target-file-system-kind
1127 Set or show the assumed file system kind for target reported file
1130 save breakpoints <filename>
1131 Save all current breakpoint definitions to a file suitable for use
1132 in a later debugging session. To read the saved breakpoint
1133 definitions, use the `source' command.
1135 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1138 info static-tracepoint-markers
1139 Display information about static tracepoint markers in the target.
1141 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1142 Define a static tracepoint by probing a marker at the given
1143 function, line, address, or marker ID.
1147 Enable and disable observer mode.
1149 set may-write-registers on|off
1150 set may-write-memory on|off
1151 set may-insert-breakpoints on|off
1152 set may-insert-tracepoints on|off
1153 set may-insert-fast-tracepoints on|off
1154 set may-interrupt on|off
1155 Set individual permissions for GDB effects on the target. Note that
1156 some of these settings can have undesirable or surprising
1157 consequences, particularly when changed in the middle of a session.
1158 For instance, disabling the writing of memory can prevent
1159 breakpoints from being inserted, cause single-stepping to fail, or
1160 even crash your program, if you disable after breakpoints have been
1161 inserted. However, GDB should not crash.
1163 set record memory-query on|off
1164 show record memory-query
1165 Control whether to stop the inferior if memory changes caused
1166 by an instruction cannot be recorded.
1171 The disassemble command now supports "start,+length" form of two arguments.
1175 ** GDB now provides a new directory location, called the python directory,
1176 where Python scripts written for GDB can be installed. The location
1177 of that directory is <data-directory>/python, where <data-directory>
1178 is the GDB data directory. For more details, see section `Scripting
1179 GDB using Python' in the manual.
1181 ** The GDB Python API now has access to breakpoints, symbols, symbol
1182 tables, program spaces, inferiors, threads and frame's code blocks.
1183 Additionally, GDB Parameters can now be created from the API, and
1184 manipulated via set/show in the CLI.
1186 ** New functions gdb.target_charset, gdb.target_wide_charset,
1187 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1189 ** New exception gdb.GdbError.
1191 ** Pretty-printers are now also looked up in the current program space.
1193 ** Pretty-printers can now be individually enabled and disabled.
1195 ** GDB now looks for names of Python scripts to auto-load in a
1196 special section named `.debug_gdb_scripts', in addition to looking
1197 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1199 * Tracepoint actions were unified with breakpoint commands. In particular,
1200 there are no longer differences in "info break" output for breakpoints and
1201 tracepoints and the "commands" command can be used for both tracepoints and
1202 regular breakpoints.
1206 ARM Symbian arm*-*-symbianelf*
1208 * D language support.
1209 GDB now supports debugging programs written in the D programming
1212 * GDB now supports the extended ptrace interface for PowerPC which is
1213 available since Linux kernel version 2.6.34. This automatically enables
1214 any hardware breakpoints and additional hardware watchpoints available in
1215 the processor. The old ptrace interface exposes just one hardware
1216 watchpoint and no hardware breakpoints.
1218 * GDB is now able to use the Data Value Compare (DVC) register available on
1219 embedded PowerPC processors to implement in hardware simple watchpoint
1220 conditions of the form:
1222 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1224 This works in native GDB running on Linux kernels with the extended ptrace
1225 interface mentioned above.
1227 *** Changes in GDB 7.1
1231 ** Namespace Support
1233 GDB now supports importing of namespaces in C++. This enables the
1234 user to inspect variables from imported namespaces. Support for
1235 namepace aliasing has also been added. So, if a namespace is
1236 aliased in the current scope (e.g. namepace C=A; ) the user can
1237 print variables using the alias (e.g. (gdb) print C::x).
1241 All known bugs relating to the printing of virtual base class were
1242 fixed. It is now possible to call overloaded static methods using a
1247 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1248 and reinterpret_cast<> are now handled by the C++ expression parser.
1252 Xilinx MicroBlaze microblaze-*-*
1257 Xilinx MicroBlaze microblaze
1260 * Multi-program debugging.
1262 GDB now has support for multi-program (a.k.a. multi-executable or
1263 multi-exec) debugging. This allows for debugging multiple inferiors
1264 simultaneously each running a different program under the same GDB
1265 session. See "Debugging Multiple Inferiors and Programs" in the
1266 manual for more information. This implied some user visible changes
1267 in the multi-inferior support. For example, "info inferiors" now
1268 lists inferiors that are not running yet or that have exited
1269 already. See also "New commands" and "New options" below.
1271 * New tracing features
1273 GDB's tracepoint facility now includes several new features:
1275 ** Trace state variables
1277 GDB tracepoints now include support for trace state variables, which
1278 are variables managed by the target agent during a tracing
1279 experiment. They are useful for tracepoints that trigger each
1280 other, so for instance one tracepoint can count hits in a variable,
1281 and then a second tracepoint has a condition that is true when the
1282 count reaches a particular value. Trace state variables share the
1283 $-syntax of GDB convenience variables, and can appear in both
1284 tracepoint actions and condition expressions. Use the "tvariable"
1285 command to create, and "info tvariables" to view; see "Trace State
1286 Variables" in the manual for more detail.
1290 GDB now includes an option for defining fast tracepoints, which
1291 targets may implement more efficiently, such as by installing a jump
1292 into the target agent rather than a trap instruction. The resulting
1293 speedup can be by two orders of magnitude or more, although the
1294 tradeoff is that some program locations on some target architectures
1295 might not allow fast tracepoint installation, for instance if the
1296 instruction to be replaced is shorter than the jump. To request a
1297 fast tracepoint, use the "ftrace" command, with syntax identical to
1298 the regular trace command.
1300 ** Disconnected tracing
1302 It is now possible to detach GDB from the target while it is running
1303 a trace experiment, then reconnect later to see how the experiment
1304 is going. In addition, a new variable disconnected-tracing lets you
1305 tell the target agent whether to continue running a trace if the
1306 connection is lost unexpectedly.
1310 GDB now has the ability to save the trace buffer into a file, and
1311 then use that file as a target, similarly to you can do with
1312 corefiles. You can select trace frames, print data that was
1313 collected in them, and use tstatus to display the state of the
1314 tracing run at the moment that it was saved. To create a trace
1315 file, use "tsave <filename>", and to use it, do "target tfile
1318 ** Circular trace buffer
1320 You can ask the target agent to handle the trace buffer as a
1321 circular buffer, discarding the oldest trace frames to make room for
1322 newer ones, by setting circular-trace-buffer to on. This feature may
1323 not be available for all target agents.
1328 The disassemble command, when invoked with two arguments, now requires
1329 the arguments to be comma-separated.
1332 The info variables command now displays variable definitions. Files
1333 which only declare a variable are not shown.
1336 The source command is now capable of sourcing Python scripts.
1337 This feature is dependent on the debugger being build with Python
1340 Related to this enhancement is also the introduction of a new command
1341 "set script-extension" (see below).
1343 * New commands (for set/show, see "New options" below)
1345 record save [<FILENAME>]
1346 Save a file (in core file format) containing the process record
1347 execution log for replay debugging at a later time.
1349 record restore <FILENAME>
1350 Restore the process record execution log that was saved at an
1351 earlier time, for replay debugging.
1353 add-inferior [-copies <N>] [-exec <FILENAME>]
1356 clone-inferior [-copies <N>] [ID]
1357 Make a new inferior ready to execute the same program another
1358 inferior has loaded.
1363 maint info program-spaces
1364 List the program spaces loaded into GDB.
1366 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1367 show remote interrupt-sequence
1368 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1369 as the sequence to the remote target in order to interrupt the execution.
1370 Ctrl-C is a default. Some system prefers BREAK which is high level of
1371 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1372 Magic SysRq g. It is BREAK signal and character 'g'.
1374 set remote interrupt-on-connect [on | off]
1375 show remote interrupt-on-connect
1376 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1377 remote target when gdb connects to it. This is needed when you debug
1380 set remotebreak [on | off]
1382 Deprecated. Use "set/show remote interrupt-sequence" instead.
1384 tvariable $NAME [ = EXP ]
1385 Create or modify a trace state variable.
1388 List trace state variables and their values.
1390 delete tvariable $NAME ...
1391 Delete one or more trace state variables.
1394 Evaluate the given expressions without collecting anything into the
1395 trace buffer. (Valid in tracepoint actions only.)
1397 ftrace FN / FILE:LINE / *ADDR
1398 Define a fast tracepoint at the given function, line, or address.
1400 * New expression syntax
1402 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1403 GDB now parses 0b101010 identically with 42.
1407 set follow-exec-mode new|same
1408 show follow-exec-mode
1409 Control whether GDB reuses the same inferior across an exec call or
1410 creates a new one. This is useful to be able to restart the old
1411 executable after the inferior having done an exec call.
1413 set default-collect EXPR, ...
1414 show default-collect
1415 Define a list of expressions to be collected at each tracepoint.
1416 This is a useful way to ensure essential items are not overlooked,
1417 such as registers or a critical global variable.
1419 set disconnected-tracing
1420 show disconnected-tracing
1421 If set to 1, the target is instructed to continue tracing if it
1422 loses its connection to GDB. If 0, the target is to stop tracing
1425 set circular-trace-buffer
1426 show circular-trace-buffer
1427 If set to on, the target is instructed to use a circular trace buffer
1428 and discard the oldest trace frames instead of stopping the trace due
1429 to a full trace buffer. If set to off, the trace stops when the buffer
1430 fills up. Some targets may not support this.
1432 set script-extension off|soft|strict
1433 show script-extension
1434 If set to "off", the debugger does not perform any script language
1435 recognition, and all sourced files are assumed to be GDB scripts.
1436 If set to "soft" (the default), files are sourced according to
1437 filename extension, falling back to GDB scripts if the first
1439 If set to "strict", files are sourced according to filename extension.
1441 set ada trust-PAD-over-XVS on|off
1442 show ada trust-PAD-over-XVS
1443 If off, activate a workaround against a bug in the debugging information
1444 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1445 the GCC sources for more information about the GNAT encoding and
1446 PAD types in particular). It is always safe to set this option to
1447 off, but this introduces a slight performance penalty. The default
1450 * Python API Improvements
1452 ** GDB provides the new class gdb.LazyString. This is useful in
1453 some pretty-printing cases. The new method gdb.Value.lazy_string
1454 provides a simple way to create objects of this type.
1456 ** The fields returned by gdb.Type.fields now have an
1457 `is_base_class' attribute.
1459 ** The new method gdb.Type.range returns the range of an array type.
1461 ** The new method gdb.parse_and_eval can be used to parse and
1462 evaluate an expression.
1464 * New remote packets
1467 Define a trace state variable.
1470 Get the current value of a trace state variable.
1473 Set desired tracing behavior upon disconnection.
1476 Set the trace buffer to be linear or circular.
1479 Get data about the tracepoints currently in use.
1483 Process record now works correctly with hardware watchpoints.
1485 Multiple bug fixes have been made to the mips-irix port, making it
1486 much more reliable. In particular:
1487 - Debugging threaded applications is now possible again. Previously,
1488 GDB would hang while starting the program, or while waiting for
1489 the program to stop at a breakpoint.
1490 - Attaching to a running process no longer hangs.
1491 - An error occurring while loading a core file has been fixed.
1492 - Changing the value of the PC register now works again. This fixes
1493 problems observed when using the "jump" command, or when calling
1494 a function from GDB, or even when assigning a new value to $pc.
1495 - With the "finish" and "return" commands, the return value for functions
1496 returning a small array is now correctly printed.
1497 - It is now possible to break on shared library code which gets executed
1498 during a shared library init phase (code executed while executing
1499 their .init section). Previously, the breakpoint would have no effect.
1500 - GDB is now able to backtrace through the signal handler for
1501 non-threaded programs.
1503 PIE (Position Independent Executable) programs debugging is now supported.
1504 This includes debugging execution of PIC (Position Independent Code) shared
1505 libraries although for that, it should be possible to run such libraries as an
1508 *** Changes in GDB 7.0
1510 * GDB now has an interface for JIT compilation. Applications that
1511 dynamically generate code can create symbol files in memory and register
1512 them with GDB. For users, the feature should work transparently, and
1513 for JIT developers, the interface is documented in the GDB manual in the
1514 "JIT Compilation Interface" chapter.
1516 * Tracepoints may now be conditional. The syntax is as for
1517 breakpoints; either an "if" clause appended to the "trace" command,
1518 or the "condition" command is available. GDB sends the condition to
1519 the target for evaluation using the same bytecode format as is used
1520 for tracepoint actions.
1522 * The disassemble command now supports: an optional /r modifier, print the
1523 raw instructions in hex as well as in symbolic form, and an optional /m
1524 modifier to print mixed source+assembly.
1526 * Process record and replay
1528 In a architecture environment that supports ``process record and
1529 replay'', ``process record and replay'' target can record a log of
1530 the process execution, and replay it with both forward and reverse
1533 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1534 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1535 set execution-direction {forward|reverse}, for targets that support
1538 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1539 feature is available with a native GDB running on kernel version
1542 * GDB now has support for multi-byte and wide character sets on the
1543 target. Strings whose character type is wchar_t, char16_t, or
1544 char32_t are now correctly printed. GDB supports wide- and unicode-
1545 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1546 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1547 `printf'. This feature requires iconv to work properly; if your
1548 system does not have a working iconv, GDB can use GNU libiconv. See
1549 the installation instructions for more information.
1551 * GDB now supports automatic retrieval of shared library files from
1552 remote targets. To use this feature, specify a system root that begins
1553 with the `remote:' prefix, either via the `set sysroot' command or via
1554 the `--with-sysroot' configure-time option.
1556 * "info sharedlibrary" now takes an optional regex of libraries to show,
1557 and it now reports if a shared library has no debugging information.
1559 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1560 now complete on file names.
1562 * When completing in expressions, gdb will attempt to limit
1563 completions to allowable structure or union fields, where appropriate.
1564 For instance, consider:
1566 # struct example { int f1; double f2; };
1567 # struct example variable;
1570 If the user types TAB at the end of this command line, the available
1571 completions will be "f1" and "f2".
1573 * Inlined functions are now supported. They show up in backtraces, and
1574 the "step", "next", and "finish" commands handle them automatically.
1576 * GDB now supports the token-splicing (##) and stringification (#)
1577 operators when expanding macros. It also supports variable-arity
1580 * GDB now supports inspecting extra signal information, exported by
1581 the new $_siginfo convenience variable. The feature is currently
1582 implemented on linux ARM, i386 and amd64.
1584 * GDB can now display the VFP floating point registers and NEON vector
1585 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1586 can provide these registers (requires Linux 2.6.30 or later). Remote
1587 and simulator targets may also provide them.
1589 * New remote packets
1592 Search memory for a sequence of bytes.
1595 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1596 operation over reliable transport links. Use of this packet is
1597 controlled by the `set remote noack-packet' command.
1600 Kill the process with the specified process ID. Use this in preference
1601 to `k' when multiprocess protocol extensions are supported.
1604 Obtains additional operating system information
1608 Read or write additional signal information.
1610 * Removed remote protocol undocumented extension
1612 An undocumented extension to the remote protocol's `S' stop reply
1613 packet that permited the stub to pass a process id was removed.
1614 Remote servers should use the `T' stop reply packet instead.
1616 * GDB now supports multiple function calling conventions according to the
1617 DWARF-2 DW_AT_calling_convention function attribute.
1619 * The SH target utilizes the aforementioned change to distinguish between gcc
1620 and Renesas calling convention. It also adds the new CLI commands
1621 `set/show sh calling-convention'.
1623 * GDB can now read compressed debug sections, as produced by GNU gold
1624 with the --compress-debug-sections=zlib flag.
1626 * 64-bit core files are now supported on AIX.
1628 * Thread switching is now supported on Tru64.
1630 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1631 which will be allocated using malloc later in program execution.
1633 * The qXfer:libraries:read remote procotol packet now allows passing a
1634 list of section offsets.
1636 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1637 conditions handling signals delivered during attach or thread creation
1638 have also been fixed.
1640 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1641 From the user's standpoint, all unqualified instances of True and False
1642 are treated as the standard definitions, regardless of context.
1644 * GDB now parses C++ symbol and type names more flexibly. For
1647 template<typename T> class C { };
1650 GDB will now correctly handle all of:
1652 ptype C<char const *>
1653 ptype C<char const*>
1654 ptype C<const char *>
1655 ptype C<const char*>
1657 * New features in the GDB remote stub, gdbserver
1659 - The "--wrapper" command-line argument tells gdbserver to use a
1660 wrapper program to launch programs for debugging.
1662 - On PowerPC and S/390 targets, it is now possible to use a single
1663 gdbserver executable to debug both 32-bit and 64-bit programs.
1664 (This requires gdbserver itself to be built as a 64-bit executable.)
1666 - gdbserver uses the new noack protocol mode for TCP connections to
1667 reduce communications latency, if also supported and enabled in GDB.
1669 - Support for the sparc64-linux-gnu target is now included in
1672 - The amd64-linux build of gdbserver now supports debugging both
1673 32-bit and 64-bit programs.
1675 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1676 now support hardware watchpoints, and will use them automatically
1681 GDB now has support for scripting using Python. Whether this is
1682 available is determined at configure time.
1684 New GDB commands can now be written in Python.
1686 * Ada tasking support
1688 Ada tasks can now be inspected in GDB. The following commands have
1692 Print the list of Ada tasks.
1694 Print detailed information about task number N.
1696 Print the task number of the current task.
1698 Switch the context of debugging to task number N.
1700 * Support for user-defined prefixed commands. The "define" command can
1701 add new commands to existing prefixes, e.g. "target".
1703 * Multi-inferior, multi-process debugging.
1705 GDB now has generalized support for multi-inferior debugging. See
1706 "Debugging Multiple Inferiors" in the manual for more information.
1707 Although availability still depends on target support, the command
1708 set is more uniform now. The GNU/Linux specific multi-forks support
1709 has been migrated to this new framework. This implied some user
1710 visible changes; see "New commands" and also "Removed commands"
1713 * Target descriptions can now describe the target OS ABI. See the
1714 "Target Description Format" section in the user manual for more
1717 * Target descriptions can now describe "compatible" architectures
1718 to indicate that the target can execute applications for a different
1719 architecture in addition to those for the main target architecture.
1720 See the "Target Description Format" section in the user manual for
1723 * Multi-architecture debugging.
1725 GDB now includes general supports for debugging applications on
1726 hybrid systems that use more than one single processor architecture
1727 at the same time. Each such hybrid architecture still requires
1728 specific support to be added. The only hybrid architecture supported
1729 in this version of GDB is the Cell Broadband Engine.
1731 * GDB now supports integrated debugging of Cell/B.E. applications that
1732 use both the PPU and SPU architectures. To enable support for hybrid
1733 Cell/B.E. debugging, you need to configure GDB to support both the
1734 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1735 --enable-targets configure option.
1737 * Non-stop mode debugging.
1739 For some targets, GDB now supports an optional mode of operation in
1740 which you can examine stopped threads while other threads continue
1741 to execute freely. This is referred to as non-stop mode, with the
1742 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1743 section in the user manual for more information.
1745 To be able to support remote non-stop debugging, a remote stub needs
1746 to implement the non-stop mode remote protocol extensions, as
1747 described in the "Remote Non-Stop" section of the user manual. The
1748 GDB remote stub, gdbserver, has been adjusted to support these
1749 extensions on linux targets.
1751 * New commands (for set/show, see "New options" below)
1753 catch syscall [NAME(S) | NUMBER(S)]
1754 Catch system calls. Arguments, which should be names of system
1755 calls or their numbers, mean catch only those syscalls. Without
1756 arguments, every syscall will be caught. When the inferior issues
1757 any of the specified syscalls, GDB will stop and announce the system
1758 call, both when it is called and when its call returns. This
1759 feature is currently available with a native GDB running on the
1760 Linux Kernel, under the following architectures: x86, x86_64,
1761 PowerPC and PowerPC64.
1763 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1765 Search memory for a sequence of bytes.
1767 maint set python print-stack
1768 maint show python print-stack
1769 Show a stack trace when an error is encountered in a Python script.
1772 Invoke CODE by passing it to the Python interpreter.
1777 These allow macros to be defined, undefined, and listed
1781 Show operating system information about processes.
1784 List the inferiors currently under GDB's control.
1787 Switch focus to inferior number NUM.
1790 Detach from inferior number NUM.
1793 Kill inferior number NUM.
1797 set spu stop-on-load
1798 show spu stop-on-load
1799 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1801 set spu auto-flush-cache
1802 show spu auto-flush-cache
1803 Control whether to automatically flush the software-managed cache
1804 during Cell/B.E. debugging.
1806 set sh calling-convention
1807 show sh calling-convention
1808 Control the calling convention used when calling SH target functions.
1811 show debug timestamp
1812 Control display of timestamps with GDB debugging output.
1814 set disassemble-next-line
1815 show disassemble-next-line
1816 Control display of disassembled source lines or instructions when
1819 set remote noack-packet
1820 show remote noack-packet
1821 Set/show the use of remote protocol QStartNoAckMode packet. See above
1822 under "New remote packets."
1824 set remote query-attached-packet
1825 show remote query-attached-packet
1826 Control use of remote protocol `qAttached' (query-attached) packet.
1828 set remote read-siginfo-object
1829 show remote read-siginfo-object
1830 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1833 set remote write-siginfo-object
1834 show remote write-siginfo-object
1835 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1838 set remote reverse-continue
1839 show remote reverse-continue
1840 Control use of remote protocol 'bc' (reverse-continue) packet.
1842 set remote reverse-step
1843 show remote reverse-step
1844 Control use of remote protocol 'bs' (reverse-step) packet.
1846 set displaced-stepping
1847 show displaced-stepping
1848 Control displaced stepping mode. Displaced stepping is a way to
1849 single-step over breakpoints without removing them from the debuggee.
1850 Also known as "out-of-line single-stepping".
1853 show debug displaced
1854 Control display of debugging info for displaced stepping.
1856 maint set internal-error
1857 maint show internal-error
1858 Control what GDB does when an internal error is detected.
1860 maint set internal-warning
1861 maint show internal-warning
1862 Control what GDB does when an internal warning is detected.
1867 Use a wrapper program to launch programs for debugging.
1869 set multiple-symbols (all|ask|cancel)
1870 show multiple-symbols
1871 The value of this variable can be changed to adjust the debugger behavior
1872 when an expression or a breakpoint location contains an ambiguous symbol
1873 name (an overloaded function name, for instance).
1875 set breakpoint always-inserted
1876 show breakpoint always-inserted
1877 Keep breakpoints always inserted in the target, as opposed to inserting
1878 them when resuming the target, and removing them when the target stops.
1879 This option can improve debugger performance on slow remote targets.
1881 set arm fallback-mode (arm|thumb|auto)
1882 show arm fallback-mode
1883 set arm force-mode (arm|thumb|auto)
1885 These commands control how ARM GDB determines whether instructions
1886 are ARM or Thumb. The default for both settings is auto, which uses
1887 the current CPSR value for instructions without symbols; previous
1888 versions of GDB behaved as if "set arm fallback-mode arm".
1890 set disable-randomization
1891 show disable-randomization
1892 Standalone programs run with the virtual address space randomization enabled
1893 by default on some platforms. This option keeps the addresses stable across
1894 multiple debugging sessions.
1898 Control whether other threads are stopped or not when some thread hits
1903 Requests that asynchronous execution is enabled in the target, if available.
1904 In this case, it's possible to resume target in the background, and interact
1905 with GDB while the target is running. "show target-async" displays the
1906 current state of asynchronous execution of the target.
1908 set target-wide-charset
1909 show target-wide-charset
1910 The target-wide-charset is the name of the character set that GDB
1911 uses when printing characters whose type is wchar_t.
1913 set tcp auto-retry (on|off)
1915 set tcp connect-timeout
1916 show tcp connect-timeout
1917 These commands allow GDB to retry failed TCP connections to a remote stub
1918 with a specified timeout period; this is useful if the stub is launched
1919 in parallel with GDB but may not be ready to accept connections immediately.
1921 set libthread-db-search-path
1922 show libthread-db-search-path
1923 Control list of directories which GDB will search for appropriate
1926 set schedule-multiple (on|off)
1927 show schedule-multiple
1928 Allow GDB to resume all threads of all processes or only threads of
1929 the current process.
1933 Use more aggressive caching for accesses to the stack. This improves
1934 performance of remote debugging (particularly backtraces) without
1935 affecting correctness.
1937 set interactive-mode (on|off|auto)
1938 show interactive-mode
1939 Control whether GDB runs in interactive mode (on) or not (off).
1940 When in interactive mode, GDB waits for the user to answer all
1941 queries. Otherwise, GDB does not wait and assumes the default
1942 answer. When set to auto (the default), GDB determines which
1943 mode to use based on the stdin settings.
1948 For program forks, this is replaced by the new more generic `info
1949 inferiors' command. To list checkpoints, you can still use the
1950 `info checkpoints' command, which was an alias for the `info forks'
1954 Replaced by the new `inferior' command. To switch between
1955 checkpoints, you can still use the `restart' command, which was an
1956 alias for the `fork' command.
1959 This is removed, since some targets don't have a notion of
1960 processes. To switch between processes, you can still use the
1961 `inferior' command using GDB's own inferior number.
1964 For program forks, this is replaced by the new more generic `kill
1965 inferior' command. To delete a checkpoint, you can still use the
1966 `delete checkpoint' command, which was an alias for the `delete
1970 For program forks, this is replaced by the new more generic `detach
1971 inferior' command. To detach a checkpoint, you can still use the
1972 `detach checkpoint' command, which was an alias for the `detach
1975 * New native configurations
1977 x86/x86_64 Darwin i[34567]86-*-darwin*
1979 x86_64 MinGW x86_64-*-mingw*
1983 Lattice Mico32 lm32-*
1984 x86 DICOS i[34567]86-*-dicos*
1985 x86_64 DICOS x86_64-*-dicos*
1988 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1989 (mingw32ce) debugging.
1995 These commands were actually not implemented on any target.
1997 *** Changes in GDB 6.8
1999 * New native configurations
2001 NetBSD/hppa hppa*-*netbsd*
2002 Xtensa GNU/Linux xtensa*-*-linux*
2006 NetBSD/hppa hppa*-*-netbsd*
2007 Xtensa GNU/Lunux xtensa*-*-linux*
2009 * Change in command line behavior -- corefiles vs. process ids.
2011 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2012 attaching to process NUMBER fails, GDB no longer attempts to open a
2013 core file named NUMBER. Attaching to a program using the -c option
2014 is no longer supported. Instead, use the '-p' or '--pid' options.
2016 * GDB can now be built as a native debugger for debugging Windows x86
2017 (mingw32) Portable Executable (PE) programs.
2019 * Pending breakpoints no longer change their number when their address
2022 * GDB now supports breakpoints with multiple locations,
2023 including breakpoints on C++ constructors, inside C++ templates,
2024 and in inlined functions.
2026 * GDB's ability to debug optimized code has been improved. GDB more
2027 accurately identifies function bodies and lexical blocks that occupy
2028 more than one contiguous range of addresses.
2030 * Target descriptions can now describe registers for PowerPC.
2032 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2033 registers on PowerPC targets.
2035 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2036 targets even when the libthread_db library is not available.
2038 * The GDB remote stub, gdbserver, now supports the new file transfer
2039 commands (remote put, remote get, and remote delete).
2041 * The GDB remote stub, gdbserver, now supports run and attach in
2042 extended-remote mode.
2044 * hppa*64*-*-hpux11* target broken
2045 The debugger is unable to start a program and fails with the following
2046 error: "Error trying to get information about dynamic linker".
2047 The gdb-6.7 release is also affected.
2049 * GDB now supports the --enable-targets= configure option to allow
2050 building a single GDB executable that supports multiple remote
2051 target architectures.
2053 * GDB now supports debugging C and C++ programs which use the
2054 Decimal Floating Point extension. In addition, the PowerPC target
2055 now has a set of pseudo-registers to inspect decimal float values
2056 stored in two consecutive float registers.
2058 * The -break-insert MI command can optionally create pending
2061 * Improved support for debugging Ada
2062 Many improvements to the Ada language support have been made. These
2064 - Better support for Ada2005 interface types
2065 - Improved handling of arrays and slices in general
2066 - Better support for Taft-amendment types
2067 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2069 - Improved command completion in Ada
2072 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2077 set print frame-arguments (all|scalars|none)
2078 show print frame-arguments
2079 The value of this variable can be changed to control which argument
2080 values should be printed by the debugger when displaying a frame.
2085 Transfer files to and from a remote target, and delete remote files.
2092 Transfer files to and from a remote target, and delete remote files.
2094 * New remote packets
2101 Open, close, read, write, and delete files on the remote system.
2104 Attach to an existing process on the remote system, in extended-remote
2108 Run a new process on the remote system, in extended-remote mode.
2110 *** Changes in GDB 6.7
2112 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2113 bfd, libiberty and opcodes, as revealed by static analysis donated by
2114 Coverity, Inc. (http://scan.coverity.com).
2116 * When looking up multiply-defined global symbols, GDB will now prefer the
2117 symbol definition in the current shared library if it was built using the
2118 -Bsymbolic linker option.
2120 * When the Text User Interface (TUI) is not configured, GDB will now
2121 recognize the -tui command-line option and print a message that the TUI
2124 * The GDB remote stub, gdbserver, now has lower overhead for high
2125 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2127 * GDB for MIPS targets now autodetects whether a remote target provides
2128 32-bit or 64-bit register values.
2130 * Support for C++ member pointers has been improved.
2132 * GDB now understands XML target descriptions, which specify the
2133 target's overall architecture. GDB can read a description from
2134 a local file or over the remote serial protocol.
2136 * Vectors of single-byte data use a new integer type which is not
2137 automatically displayed as character or string data.
2139 * The /s format now works with the print command. It displays
2140 arrays of single-byte integers and pointers to single-byte integers
2143 * Target descriptions can now describe target-specific registers,
2144 for architectures which have implemented the support (currently
2145 only ARM, M68K, and MIPS).
2147 * GDB and the GDB remote stub, gdbserver, now support the XScale
2150 * The GDB remote stub, gdbserver, has been updated to support
2151 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2152 has been rewritten to use the standard GDB remote protocol.
2154 * GDB can now step into C++ functions which are called through thunks.
2156 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2158 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2159 layout. It also supports a TextSeg= and DataSeg= response when only
2160 segment base addresses (rather than offsets) are available.
2162 * The /i format now outputs any trailing branch delay slot instructions
2163 immediately following the last instruction within the count specified.
2165 * The GDB remote protocol "T" stop reply packet now supports a
2166 "library" response. Combined with the new "qXfer:libraries:read"
2167 packet, this response allows GDB to debug shared libraries on targets
2168 where the operating system manages the list of loaded libraries (e.g.
2169 Windows and SymbianOS).
2171 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2172 (DLLs) on Windows and Windows CE targets.
2174 * GDB now supports a faster verification that a .debug file matches its binary
2175 according to its build-id signature, if the signature is present.
2181 Enable or disable hardware flow control (RTS/CTS) on the serial port
2182 when debugging using remote targets.
2184 set mem inaccessible-by-default
2185 show mem inaccessible-by-default
2186 If the target supplies a memory map, for instance via the remote
2187 protocol's "qXfer:memory-map:read" packet, setting this variable
2188 prevents GDB from accessing memory outside the memory map. This
2189 is useful for targets with memory mapped registers or which react
2190 badly to accesses of unmapped address space.
2192 set breakpoint auto-hw
2193 show breakpoint auto-hw
2194 If the target supplies a memory map, for instance via the remote
2195 protocol's "qXfer:memory-map:read" packet, setting this variable
2196 lets GDB use hardware breakpoints automatically for memory regions
2197 where it can not use software breakpoints. This covers both the
2198 "break" command and internal breakpoints used for other commands
2199 including "next" and "finish".
2202 catch exception unhandled
2203 Stop the program execution when Ada exceptions are raised.
2206 Stop the program execution when an Ada assertion failed.
2210 Set an alternate system root for target files. This is a more
2211 general version of "set solib-absolute-prefix", which is now
2212 an alias to "set sysroot".
2215 Provide extended SPU facility status information. This set of
2216 commands is available only when debugging the Cell/B.E. SPU
2219 * New native configurations
2221 OpenBSD/sh sh*-*openbsd*
2224 unset tdesc filename
2226 Use the specified local file as an XML target description, and do
2227 not query the target for its built-in description.
2231 OpenBSD/sh sh*-*-openbsd*
2232 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2233 Toshiba Media Processor mep-elf
2235 * New remote packets
2238 Ignore the specified signals; pass them directly to the debugged program
2239 without stopping other threads or reporting them to GDB.
2241 qXfer:features:read:
2242 Read an XML target description from the target, which describes its
2247 Read or write contents of an spufs file on the target system. These
2248 packets are available only on the Cell/B.E. SPU architecture.
2250 qXfer:libraries:read:
2251 Report the loaded shared libraries. Combined with new "T" packet
2252 response, this packet allows GDB to debug shared libraries on
2253 targets where the operating system manages the list of loaded
2254 libraries (e.g. Windows and SymbianOS).
2258 Support for these obsolete configurations has been removed.
2266 i[34567]86-*-lynxos*
2267 i[34567]86-*-netware*
2268 i[34567]86-*-sco3.2v5*
2269 i[34567]86-*-sco3.2v4*
2271 i[34567]86-*-sysv4.2*
2274 i[34567]86-*-unixware2*
2275 i[34567]86-*-unixware*
2284 * Other removed features
2291 Various m68k-only ROM monitors.
2298 Various Renesas ROM monitors and debugging interfaces for SH and
2303 Support for a Macraigor serial interface to on-chip debugging.
2304 GDB does not directly support the newer parallel or USB
2309 A debug information format. The predecessor to DWARF 2 and
2310 DWARF 3, which are still supported.
2312 Support for the HP aCC compiler on HP-UX/PA-RISC
2314 SOM-encapsulated symbolic debugging information, automatic
2315 invocation of pxdb, and the aCC custom C++ ABI. This does not
2316 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2317 with aCC can still be debugged on an assembly level.
2319 MIPS ".pdr" sections
2321 A MIPS-specific format used to describe stack frame layout
2322 in debugging information.
2326 GDB could work with an older version of Guile to debug
2327 the interpreter and Scheme programs running in it.
2329 set mips stack-arg-size
2330 set mips saved-gpreg-size
2332 Use "set mips abi" to control parameter passing for MIPS.
2334 *** Changes in GDB 6.6
2339 Cell Broadband Engine SPU spu-elf
2341 * GDB can now be configured as a cross-debugger targeting native Windows
2342 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2343 running on a Windows system over TCP/IP to debug Windows programs.
2345 * The GDB remote stub, gdbserver, has been updated to support Windows and
2346 Cygwin debugging. Both single-threaded and multi-threaded programs are
2349 * The "set trust-readonly-sections" command works again. This command was
2350 broken in GDB 6.3, 6.4, and 6.5.
2352 * The "load" command now supports writing to flash memory, if the remote
2353 stub provides the required support.
2355 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2356 longer requires symbolic debug information (e.g. DWARF-2).
2361 unset substitute-path
2362 show substitute-path
2363 Manage a list of substitution rules that GDB uses to rewrite the name
2364 of the directories where the sources are located. This can be useful
2365 for instance when the sources were moved to a different location
2366 between compilation and debugging.
2370 Print each CLI command as it is executed. Each command is prefixed with
2371 a number of `+' symbols representing the nesting depth.
2372 The source command now has a `-v' option to enable the same feature.
2376 The ARM Demon monitor support (RDP protocol, "target rdp").
2378 Kernel Object Display, an embedded debugging feature which only worked with
2379 an obsolete version of Cisco IOS.
2381 The 'set download-write-size' and 'show download-write-size' commands.
2383 * New remote packets
2386 Tell a stub about GDB client features, and request remote target features.
2387 The first feature implemented is PacketSize, which allows the target to
2388 specify the size of packets it can handle - to minimize the number of
2389 packets required and improve performance when connected to a remote
2393 Fetch an OS auxilliary vector from the remote stub. This packet is a
2394 more efficient replacement for qPart:auxv:read.
2396 qXfer:memory-map:read:
2397 Fetch a memory map from the remote stub, including information about
2398 RAM, ROM, and flash memory devices.
2403 Erase and program a flash memory device.
2405 * Removed remote packets
2408 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2409 used it, and only gdbserver implemented it.
2411 *** Changes in GDB 6.5
2415 Renesas M32C/M16C m32c-elf
2417 Morpho Technologies ms1 ms1-elf
2421 init-if-undefined Initialize a convenience variable, but
2422 only if it doesn't already have a value.
2424 The following commands are presently only implemented for native GNU/Linux:
2426 checkpoint Save a snapshot of the program state.
2428 restart <n> Return the program state to a
2429 previously saved state.
2431 info checkpoints List currently saved checkpoints.
2433 delete-checkpoint <n> Delete a previously saved checkpoint.
2435 set|show detach-on-fork Tell gdb whether to detach from a newly
2436 forked process, or to keep debugging it.
2438 info forks List forks of the user program that
2439 are available to be debugged.
2441 fork <n> Switch to debugging one of several
2442 forks of the user program that are
2443 available to be debugged.
2445 delete-fork <n> Delete a fork from the list of forks
2446 that are available to be debugged (and
2447 kill the forked process).
2449 detach-fork <n> Delete a fork from the list of forks
2450 that are available to be debugged (and
2451 allow the process to continue).
2455 Morpho Technologies ms2 ms1-elf
2457 * Improved Windows host support
2459 GDB now builds as a cross debugger hosted on i686-mingw32, including
2460 native console support, and remote communications using either
2461 network sockets or serial ports.
2463 * Improved Modula-2 language support
2465 GDB can now print most types in the Modula-2 syntax. This includes:
2466 basic types, set types, record types, enumerated types, range types,
2467 pointer types and ARRAY types. Procedure var parameters are correctly
2468 printed and hexadecimal addresses and character constants are also
2469 written in the Modula-2 syntax. Best results can be obtained by using
2470 GNU Modula-2 together with the -gdwarf-2 command line option.
2474 The ARM rdi-share module.
2476 The Netware NLM debug server.
2478 *** Changes in GDB 6.4
2480 * New native configurations
2482 OpenBSD/arm arm*-*-openbsd*
2483 OpenBSD/mips64 mips64-*-openbsd*
2487 Morpho Technologies ms1 ms1-elf
2489 * New command line options
2491 --batch-silent As for --batch, but totally silent.
2492 --return-child-result The debugger will exist with the same value
2493 the child (debugged) program exited with.
2494 --eval-command COMMAND, -ex COMMAND
2495 Execute a single GDB CLI command. This may be
2496 specified multiple times and in conjunction
2497 with the --command (-x) option.
2499 * Deprecated commands removed
2501 The following commands, that were deprecated in 2000, have been
2505 set|show arm disassembly-flavor set|show arm disassembler
2506 othernames set arm disassembler
2507 set|show remotedebug set|show debug remote
2508 set|show archdebug set|show debug arch
2509 set|show eventdebug set|show debug event
2512 * New BSD user-level threads support
2514 It is now possible to debug programs using the user-level threads
2515 library on OpenBSD and FreeBSD. Currently supported (target)
2518 FreeBSD/amd64 x86_64-*-freebsd*
2519 FreeBSD/i386 i386-*-freebsd*
2520 OpenBSD/i386 i386-*-openbsd*
2522 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2523 are not yet supported.
2525 * New support for Matsushita MN10300 w/sim added
2526 (Work in progress). mn10300-elf.
2528 * REMOVED configurations and files
2530 VxWorks and the XDR protocol *-*-vxworks
2531 Motorola MCORE mcore-*-*
2532 National Semiconductor NS32000 ns32k-*-*
2534 * New "set print array-indexes" command
2536 After turning this setting "on", GDB prints the index of each element
2537 when displaying arrays. The default is "off" to preserve the previous
2540 * VAX floating point support
2542 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2544 * User-defined command support
2546 In addition to using $arg0..$arg9 for argument passing, it is now possible
2547 to use $argc to determine now many arguments have been passed. See the
2548 section on user-defined commands in the user manual for more information.
2550 *** Changes in GDB 6.3:
2552 * New command line option
2554 GDB now accepts -l followed by a number to set the timeout for remote
2557 * GDB works with GCC -feliminate-dwarf2-dups
2559 GDB now supports a more compact representation of DWARF-2 debug
2560 information using DW_FORM_ref_addr references. These are produced
2561 by GCC with the option -feliminate-dwarf2-dups and also by some
2562 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2563 to use -feliminate-dwarf2-dups.
2565 * Internationalization
2567 When supported by the host system, GDB will be built with
2568 internationalization (libintl). The task of marking up the sources is
2569 continued, we're looking forward to our first translation.
2573 Initial support for debugging programs compiled with the GNAT
2574 implementation of the Ada programming language has been integrated
2575 into GDB. In this release, support is limited to expression evaluation.
2577 * New native configurations
2579 GNU/Linux/m32r m32r-*-linux-gnu
2583 GDB's remote protocol now includes support for the 'p' packet. This
2584 packet is used to fetch individual registers from a remote inferior.
2586 * END-OF-LIFE registers[] compatibility module
2588 GDB's internal register infrastructure has been completely rewritten.
2589 The new infrastructure making possible the implementation of key new
2590 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2593 GDB 6.3 will be the last release to include the the registers[]
2594 compatibility module that allowed out-of-date configurations to
2595 continue to work. This change directly impacts the following
2605 powerpc bdm protocol
2607 Unless there is activity to revive these configurations, they will be
2608 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2610 * OBSOLETE configurations and files
2612 Configurations that have been declared obsolete in this release have
2613 been commented out. Unless there is activity to revive these
2614 configurations, the next release of GDB will have their sources
2615 permanently REMOVED.
2624 *** Changes in GDB 6.2.1:
2626 * MIPS `break main; run' gave an heuristic-fence-post warning
2628 When attempting to run even a simple program, a warning about
2629 heuristic-fence-post being hit would be reported. This problem has
2632 * MIPS IRIX 'long double' crashed GDB
2634 When examining a long double variable, GDB would get a segmentation
2635 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2636 IRIX long double values).
2640 A bug in the VAX stack code was causing problems with the "next"
2641 command. This problem has been fixed.
2643 *** Changes in GDB 6.2:
2645 * Fix for ``many threads''
2647 On GNU/Linux systems that use the NPTL threads library, a program
2648 rapidly creating and deleting threads would confuse GDB leading to the
2651 ptrace: No such process.
2652 thread_db_get_info: cannot get thread info: generic error
2654 This problem has been fixed.
2656 * "-async" and "-noasync" options removed.
2658 Support for the broken "-noasync" option has been removed (it caused
2661 * New ``start'' command.
2663 This command runs the program until the begining of the main procedure.
2665 * New BSD Kernel Data Access Library (libkvm) interface
2667 Using ``target kvm'' it is now possible to debug kernel core dumps and
2668 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2669 platforms. Currently supported (native-only) configurations are:
2671 FreeBSD/amd64 x86_64-*-freebsd*
2672 FreeBSD/i386 i?86-*-freebsd*
2673 NetBSD/i386 i?86-*-netbsd*
2674 NetBSD/m68k m68*-*-netbsd*
2675 NetBSD/sparc sparc-*-netbsd*
2676 OpenBSD/amd64 x86_64-*-openbsd*
2677 OpenBSD/i386 i?86-*-openbsd*
2678 OpenBSD/m68k m68*-openbsd*
2679 OpenBSD/sparc sparc-*-openbsd*
2681 * Signal trampoline code overhauled
2683 Many generic problems with GDB's signal handling code have been fixed.
2684 These include: backtraces through non-contiguous stacks; recognition
2685 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2686 call; backtrace through a signal trampoline; step into and out of
2687 signal handlers; and single-stepping in the signal trampoline.
2689 Please note that kernel bugs are a limiting factor here. These
2690 features have been shown to work on an s390 GNU/Linux system that
2691 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2693 * Cygwin support for DWARF 2 added.
2695 * New native configurations
2697 GNU/Linux/hppa hppa*-*-linux*
2698 OpenBSD/hppa hppa*-*-openbsd*
2699 OpenBSD/m68k m68*-*-openbsd*
2700 OpenBSD/m88k m88*-*-openbsd*
2701 OpenBSD/powerpc powerpc-*-openbsd*
2702 NetBSD/vax vax-*-netbsd*
2703 OpenBSD/vax vax-*-openbsd*
2705 * END-OF-LIFE frame compatibility module
2707 GDB's internal frame infrastructure has been completely rewritten.
2708 The new infrastructure making it possible to support key new features
2709 including DWARF 2 Call Frame Information. To aid in the task of
2710 migrating old configurations to this new infrastructure, a
2711 compatibility module, that allowed old configurations to continue to
2712 work, was also included.
2714 GDB 6.2 will be the last release to include this frame compatibility
2715 module. This change directly impacts the following configurations:
2725 Unless there is activity to revive these configurations, they will be
2726 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2728 * REMOVED configurations and files
2730 Sun 3, running SunOS 3 m68*-*-sunos3*
2731 Sun 3, running SunOS 4 m68*-*-sunos4*
2732 Sun 2, running SunOS 3 m68000-*-sunos3*
2733 Sun 2, running SunOS 4 m68000-*-sunos4*
2734 Motorola 680x0 running LynxOS m68*-*-lynxos*
2735 AT&T 3b1/Unix pc m68*-att-*
2736 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2737 decstation mips-dec-* mips-little-*
2738 riscos mips-*-riscos* mips-*-sysv*
2739 sonymips mips-sony-*
2740 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2742 *** Changes in GDB 6.1.1:
2744 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2746 The TUI (Text-mode User Interface) is now built as part of a default
2747 GDB configuration. It is enabled by either selecting the TUI with the
2748 command line option "-i=tui" or by running the separate "gdbtui"
2749 program. For more information on the TUI, see the manual "Debugging
2752 * Pending breakpoint support (also included in GDB 6.1)
2754 Support has been added to allow you to specify breakpoints in shared
2755 libraries that have not yet been loaded. If a breakpoint location
2756 cannot be found, and the "breakpoint pending" option is set to auto,
2757 GDB queries you if you wish to make the breakpoint pending on a future
2758 shared-library load. If and when GDB resolves the breakpoint symbol,
2759 the pending breakpoint is removed as one or more regular breakpoints
2762 Pending breakpoints are very useful for GCJ Java debugging.
2764 * Fixed ISO-C build problems
2766 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2767 non ISO-C code that stopped them being built using a more strict ISO-C
2768 compiler (e.g., IBM's C compiler).
2770 * Fixed build problem on IRIX 5
2772 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2773 wasn't able to compile compile on an IRIX 5 system.
2775 * Added execute permission to gdb/gdbserver/configure
2777 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2778 permission. This bug would cause configure to fail on a number of
2779 systems (Solaris, IRIX). Ref: server/519.
2781 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2783 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2784 has been updated to use constant array sizes.
2786 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2788 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2789 its generated DWARF Call Frame Info. This encoding was causing GDB to
2790 panic, that panic has been fixed. Ref: gdb/1628.
2792 * Fixed a problem when examining parameters in shared library code.
2794 When examining parameters in optimized shared library code generated
2795 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2796 not available''. GDB now correctly displays the variable's value.
2798 *** Changes in GDB 6.1:
2800 * Removed --with-mmalloc
2802 Support for the mmalloc memory manager has been removed, as it
2803 conflicted with the internal gdb byte cache.
2805 * Changes in AMD64 configurations
2807 The AMD64 target now includes the %cs and %ss registers. As a result
2808 the AMD64 remote protocol has changed; this affects the floating-point
2809 and SSE registers. If you rely on those registers for your debugging,
2810 you should upgrade gdbserver on the remote side.
2812 * Revised SPARC target
2814 The SPARC target has been completely revised, incorporating the
2815 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2816 support for LynxOS and SunOS 4 has been dropped. Calling functions
2817 from within GDB on operating systems with a non-executable stack
2818 (Solaris, OpenBSD) now works.
2822 GDB has a new C++ demangler which does a better job on the mangled
2823 names generated by current versions of g++. It also runs faster, so
2824 with this and other changes gdb should now start faster on large C++
2827 * DWARF 2 Location Expressions
2829 GDB support for location expressions has been extended to support function
2830 arguments and frame bases. Older versions of GDB could crash when they
2833 * C++ nested types and namespaces
2835 GDB's support for nested types and namespaces in C++ has been
2836 improved, especially if you use the DWARF 2 debugging format. (This
2837 is the default for recent versions of GCC on most platforms.)
2838 Specifically, if you have a class "Inner" defined within a class or
2839 namespace "Outer", then GDB realizes that the class's name is
2840 "Outer::Inner", not simply "Inner". This should greatly reduce the
2841 frequency of complaints about not finding RTTI symbols. In addition,
2842 if you are stopped at inside of a function defined within a namespace,
2843 GDB modifies its name lookup accordingly.
2845 * New native configurations
2847 NetBSD/amd64 x86_64-*-netbsd*
2848 OpenBSD/amd64 x86_64-*-openbsd*
2849 OpenBSD/alpha alpha*-*-openbsd*
2850 OpenBSD/sparc sparc-*-openbsd*
2851 OpenBSD/sparc64 sparc64-*-openbsd*
2853 * New debugging protocols
2855 M32R with SDI protocol m32r-*-elf*
2857 * "set prompt-escape-char" command deleted.
2859 The command "set prompt-escape-char" has been deleted. This command,
2860 and its very obscure effet on GDB's prompt, was never documented,
2861 tested, nor mentioned in the NEWS file.
2863 * OBSOLETE configurations and files
2865 Configurations that have been declared obsolete in this release have
2866 been commented out. Unless there is activity to revive these
2867 configurations, the next release of GDB will have their sources
2868 permanently REMOVED.
2870 Sun 3, running SunOS 3 m68*-*-sunos3*
2871 Sun 3, running SunOS 4 m68*-*-sunos4*
2872 Sun 2, running SunOS 3 m68000-*-sunos3*
2873 Sun 2, running SunOS 4 m68000-*-sunos4*
2874 Motorola 680x0 running LynxOS m68*-*-lynxos*
2875 AT&T 3b1/Unix pc m68*-att-*
2876 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2877 decstation mips-dec-* mips-little-*
2878 riscos mips-*-riscos* mips-*-sysv*
2879 sonymips mips-sony-*
2880 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2882 * REMOVED configurations and files
2884 SGI Irix-4.x mips-sgi-irix4 or iris4
2885 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2886 Z8000 simulator z8k-zilog-none or z8ksim
2887 Matsushita MN10200 w/simulator mn10200-*-*
2888 H8/500 simulator h8500-hitachi-hms or h8500hms
2889 HP/PA running BSD hppa*-*-bsd*
2890 HP/PA running OSF/1 hppa*-*-osf*
2891 HP/PA Pro target hppa*-*-pro*
2892 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2893 386BSD i[3456]86-*-bsd*
2894 Sequent family i[3456]86-sequent-sysv4*
2895 i[3456]86-sequent-sysv*
2896 i[3456]86-sequent-bsd*
2897 SPARC running LynxOS sparc-*-lynxos*
2898 SPARC running SunOS 4 sparc-*-sunos4*
2899 Tsqware Sparclet sparclet-*-*
2900 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2902 *** Changes in GDB 6.0:
2906 Support for debugging the Objective-C programming language has been
2907 integrated into GDB.
2909 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2911 DWARF 2's Call Frame Information makes available compiler generated
2912 information that more exactly describes the program's run-time stack.
2913 By using this information, GDB is able to provide more robust stack
2916 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2917 have been updated to use a new backtrace mechanism which includes
2918 DWARF 2 CFI support.
2922 GDB's remote protocol has been extended to include support for hosted
2923 file I/O (where the remote target uses GDB's file system). See GDB's
2924 remote protocol documentation for details.
2926 * All targets using the new architecture framework.
2928 All of GDB's targets have been updated to use the new internal
2929 architecture framework. The way is now open for future GDB releases
2930 to include cross-architecture native debugging support (i386 on amd64,
2933 * GNU/Linux's Thread Local Storage (TLS)
2935 GDB now includes support for for the GNU/Linux implementation of
2936 per-thread variables.
2938 * GNU/Linux's Native POSIX Thread Library (NPTL)
2940 GDB's thread code has been updated to work with either the new
2941 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2943 * Separate debug info.
2945 GDB, in conjunction with BINUTILS, now supports a mechanism for
2946 automatically loading debug information from a separate file. Instead
2947 of shipping full debug and non-debug versions of system libraries,
2948 system integrators can now instead ship just the stripped libraries
2949 and optional debug files.
2951 * DWARF 2 Location Expressions
2953 DWARF 2 Location Expressions allow the compiler to more completely
2954 describe the location of variables (even in optimized code) to the
2957 GDB now includes preliminary support for location expressions (support
2958 for DW_OP_piece is still missing).
2962 A number of long standing bugs that caused GDB to die while starting a
2963 Java application have been fixed. GDB's Java support is now
2964 considered "useable".
2966 * GNU/Linux support for fork, vfork, and exec.
2968 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2969 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2972 * GDB supports logging output to a file
2974 There are two new commands, "set logging" and "show logging", which can be
2975 used to capture GDB's output to a file.
2977 * The meaning of "detach" has changed for gdbserver
2979 The "detach" command will now resume the application, as documented. To
2980 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2983 * d10v, m68hc11 `regs' command deprecated
2985 The `info registers' command has been updated so that it displays the
2986 registers using a format identical to the old `regs' command.
2990 A new command, "maint set profile on/off", has been added. This command can
2991 be used to enable or disable profiling while running GDB, to profile a
2992 session or a set of commands. In addition there is a new configure switch,
2993 "--enable-profiling", which will cause GDB to be compiled with profiling
2994 data, for more informative profiling results.
2996 * Default MI syntax changed to "mi2".
2998 The default MI (machine interface) syntax, enabled by the command line
2999 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3000 "mi1", can be enabled by specifying the option "-i=mi1".
3002 Support for the original "mi0" syntax (included in GDB 5.0) has been
3005 Fix for gdb/192: removed extraneous space when displaying frame level.
3006 Fix for gdb/672: update changelist is now output in mi list format.
3007 Fix for gdb/702: a -var-assign that updates the value now shows up
3008 in a subsequent -var-update.
3010 * New native configurations.
3012 FreeBSD/amd64 x86_64-*-freebsd*
3014 * Multi-arched targets.
3016 HP/PA HPUX11 hppa*-*-hpux*
3017 Renesas M32R/D w/simulator m32r-*-elf*
3019 * OBSOLETE configurations and files
3021 Configurations that have been declared obsolete in this release have
3022 been commented out. Unless there is activity to revive these
3023 configurations, the next release of GDB will have their sources
3024 permanently REMOVED.
3026 Z8000 simulator z8k-zilog-none or z8ksim
3027 Matsushita MN10200 w/simulator mn10200-*-*
3028 H8/500 simulator h8500-hitachi-hms or h8500hms
3029 HP/PA running BSD hppa*-*-bsd*
3030 HP/PA running OSF/1 hppa*-*-osf*
3031 HP/PA Pro target hppa*-*-pro*
3032 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3033 Sequent family i[3456]86-sequent-sysv4*
3034 i[3456]86-sequent-sysv*
3035 i[3456]86-sequent-bsd*
3036 Tsqware Sparclet sparclet-*-*
3037 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3039 * REMOVED configurations and files
3042 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3043 IBM AIX PS/2 i[3456]86-*-aix
3044 i386 running Mach 3.0 i[3456]86-*-mach3*
3045 i386 running Mach i[3456]86-*-mach*
3046 i386 running OSF/1 i[3456]86-*osf1mk*
3047 HP/Apollo 68k Family m68*-apollo*-sysv*,
3049 m68*-hp-bsd*, m68*-hp-hpux*
3050 Argonaut Risc Chip (ARC) arc-*-*
3051 Mitsubishi D30V d30v-*-*
3052 Fujitsu FR30 fr30-*-elf*
3053 OS/9000 i[34]86-*-os9k
3054 I960 with MON960 i960-*-coff
3056 * MIPS $fp behavior changed
3058 The convenience variable $fp, for the MIPS, now consistently returns
3059 the address of the current frame's base. Previously, depending on the
3060 context, $fp could refer to either $sp or the current frame's base
3061 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3062 The GNU Source-Level Debugger''.
3064 *** Changes in GDB 5.3:
3066 * GNU/Linux shared library multi-threaded performance improved.
3068 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3069 `/proc', in preference to `ptrace' for memory reads. This may result
3070 in an improvement in the start-up time of multi-threaded, shared
3071 library applications when run under GDB. One GDB user writes: ``loads
3072 shared libs like mad''.
3074 * ``gdbserver'' now supports multi-threaded applications on some targets
3076 Support for debugging multi-threaded applications which use
3077 the GNU/Linux LinuxThreads package has been added for
3078 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3079 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3081 * GDB now supports C/C++ preprocessor macros.
3083 GDB now expands preprocessor macro invocations in C/C++ expressions,
3084 and provides various commands for showing macro definitions and how
3087 The new command `macro expand EXPRESSION' expands any macro
3088 invocations in expression, and shows the result.
3090 The new command `show macro MACRO-NAME' shows the definition of the
3091 macro named MACRO-NAME, and where it was defined.
3093 Most compilers don't include information about macros in the debugging
3094 information by default. In GCC 3.1, for example, you need to compile
3095 your program with the options `-gdwarf-2 -g3'. If the macro
3096 information is present in the executable, GDB will read it.
3098 * Multi-arched targets.
3100 DEC Alpha (partial) alpha*-*-*
3101 DEC VAX (partial) vax-*-*
3103 National Semiconductor NS32000 (partial) ns32k-*-*
3104 Motorola 68000 (partial) m68k-*-*
3105 Motorola MCORE mcore-*-*
3109 Fujitsu FRV architecture added by Red Hat frv*-*-*
3112 * New native configurations
3114 Alpha NetBSD alpha*-*-netbsd*
3115 SH NetBSD sh*-*-netbsdelf*
3116 MIPS NetBSD mips*-*-netbsd*
3117 UltraSPARC NetBSD sparc64-*-netbsd*
3119 * OBSOLETE configurations and files
3121 Configurations that have been declared obsolete in this release have
3122 been commented out. Unless there is activity to revive these
3123 configurations, the next release of GDB will have their sources
3124 permanently REMOVED.
3126 Mitsubishi D30V d30v-*-*
3127 OS/9000 i[34]86-*-os9k
3128 IBM AIX PS/2 i[3456]86-*-aix
3129 Fujitsu FR30 fr30-*-elf*
3130 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3131 Argonaut Risc Chip (ARC) arc-*-*
3132 i386 running Mach 3.0 i[3456]86-*-mach3*
3133 i386 running Mach i[3456]86-*-mach*
3134 i386 running OSF/1 i[3456]86-*osf1mk*
3135 HP/Apollo 68k Family m68*-apollo*-sysv*,
3137 m68*-hp-bsd*, m68*-hp-hpux*
3138 I960 with MON960 i960-*-coff
3140 * OBSOLETE languages
3142 CHILL, a Pascal like language used by telecommunications companies.
3144 * REMOVED configurations and files
3146 AMD 29k family via UDI a29k-amd-udi, udi29k
3147 A29K VxWorks a29k-*-vxworks
3148 AMD 29000 embedded, using EBMON a29k-none-none
3149 AMD 29000 embedded with COFF a29k-none-coff
3150 AMD 29000 embedded with a.out a29k-none-aout
3152 testsuite/gdb.hp/gdb.threads-hp/ directory
3154 * New command "set max-user-call-depth <nnn>"
3156 This command allows the user to limit the call depth of user-defined
3157 commands. The default is 1024.
3159 * Changes in FreeBSD/i386 native debugging.
3161 Support for the "generate-core-file" has been added.
3163 * New commands "dump", "append", and "restore".
3165 These commands allow data to be copied from target memory
3166 to a bfd-format or binary file (dump and append), and back
3167 from a file into memory (restore).
3169 * Improved "next/step" support on multi-processor Alpha Tru64.
3171 The previous single-step mechanism could cause unpredictable problems,
3172 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3173 of a software single-step mechanism prevents this.
3175 *** Changes in GDB 5.2.1:
3183 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3184 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3185 Fix, by Joel Brobecker imported from mainline.
3187 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3188 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3189 Fix, by Fred Fish, imported from mainline.
3191 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3192 Surprisingly enough, it works now.
3193 By Michal Ludvig, imported from mainline.
3195 i386 hardware watchpoint support:
3196 avoid misses on second run for some targets.
3197 By Pierre Muller, imported from mainline.
3199 *** Changes in GDB 5.2:
3201 * New command "set trust-readonly-sections on[off]".
3203 This command is a hint that tells gdb that read-only sections
3204 really are read-only (ie. that their contents will not change).
3205 In this mode, gdb will go to the object file rather than the
3206 target to read memory from read-only sections (such as ".text").
3207 This can be a significant performance improvement on some
3208 (notably embedded) targets.
3210 * New command "generate-core-file" (or "gcore").
3212 This new gdb command allows the user to drop a core file of the child
3213 process state at any time. So far it's been implemented only for
3214 GNU/Linux and Solaris, but should be relatively easily ported to other
3215 hosts. Argument is core file name (defaults to core.<pid>).
3217 * New command line option
3219 GDB now accepts --pid or -p followed by a process id.
3221 * Change in command line behavior -- corefiles vs. process ids.
3223 There is a subtle behavior in the way in which GDB handles
3224 command line arguments. The first non-flag argument is always
3225 a program to debug, but the second non-flag argument may either
3226 be a corefile or a process id. Previously, GDB would attempt to
3227 open the second argument as a corefile, and if that failed, would
3228 issue a superfluous error message and then attempt to attach it as
3229 a process. Now, if the second argument begins with a non-digit,
3230 it will be treated as a corefile. If it begins with a digit,
3231 GDB will attempt to attach it as a process, and if no such process
3232 is found, will then attempt to open it as a corefile.
3234 * Changes in ARM configurations.
3236 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3237 configuration is fully multi-arch.
3239 * New native configurations
3241 ARM NetBSD arm*-*-netbsd*
3242 x86 OpenBSD i[3456]86-*-openbsd*
3243 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3244 Sparc64 running FreeBSD sparc64-*-freebsd*
3248 Sanyo XStormy16 xstormy16-elf
3250 * OBSOLETE configurations and files
3252 Configurations that have been declared obsolete in this release have
3253 been commented out. Unless there is activity to revive these
3254 configurations, the next release of GDB will have their sources
3255 permanently REMOVED.
3257 AMD 29k family via UDI a29k-amd-udi, udi29k
3258 A29K VxWorks a29k-*-vxworks
3259 AMD 29000 embedded, using EBMON a29k-none-none
3260 AMD 29000 embedded with COFF a29k-none-coff
3261 AMD 29000 embedded with a.out a29k-none-aout
3263 testsuite/gdb.hp/gdb.threads-hp/ directory
3265 * REMOVED configurations and files
3267 TI TMS320C80 tic80-*-*
3269 PowerPC Solaris powerpcle-*-solaris*
3270 PowerPC Windows NT powerpcle-*-cygwin32
3271 PowerPC Netware powerpc-*-netware*
3272 Harris/CXUX m88k m88*-harris-cxux*
3273 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3274 ns32k-utek-sysv* ns32k-utek-*
3275 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3276 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3277 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3278 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3279 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3281 * Changes to command line processing
3283 The new `--args' feature can be used to specify command-line arguments
3284 for the inferior from gdb's command line.
3286 * Changes to key bindings
3288 There is a new `operate-and-get-next' function bound to `C-o'.
3290 *** Changes in GDB 5.1.1
3292 Fix compile problem on DJGPP.
3294 Fix a problem with floating-point registers on the i386 being
3297 Fix to stop GDB crashing on .debug_str debug info.
3299 Numerous documentation fixes.
3301 Numerous testsuite fixes.
3303 *** Changes in GDB 5.1:
3305 * New native configurations
3307 Alpha FreeBSD alpha*-*-freebsd*
3308 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3309 MIPS GNU/Linux mips*-*-linux*
3310 MIPS SGI Irix 6.x mips*-sgi-irix6*
3311 ia64 AIX ia64-*-aix*
3312 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3316 Motorola 68HC11 and 68HC12 m68hc11-elf
3318 UltraSparc running GNU/Linux sparc64-*-linux*
3320 * OBSOLETE configurations and files
3322 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3323 Harris/CXUX m88k m88*-harris-cxux*
3324 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3325 ns32k-utek-sysv* ns32k-utek-*
3326 TI TMS320C80 tic80-*-*
3328 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3329 PowerPC Solaris powerpcle-*-solaris*
3330 PowerPC Windows NT powerpcle-*-cygwin32
3331 PowerPC Netware powerpc-*-netware*
3332 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3333 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3334 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3335 Apple Macintosh (MPW) host N/A
3337 stuff.c (Program to stuff files into a specially prepared space in kdb)
3338 kdb-start.c (Main loop for the standalone kernel debugger)
3340 Configurations that have been declared obsolete in this release have
3341 been commented out. Unless there is activity to revive these
3342 configurations, the next release of GDB will have their sources
3343 permanently REMOVED.
3345 * REMOVED configurations and files
3347 Altos 3068 m68*-altos-*
3348 Convex c1-*-*, c2-*-*
3350 ARM RISCix arm-*-* (as host)
3354 * GDB has been converted to ISO C.
3356 GDB's source code has been converted to ISO C. In particular, the
3357 sources are fully protoized, and rely on standard headers being
3362 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3364 * The MI enabled by default.
3366 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3367 revised and enabled by default. Packages which use GDB as a debugging
3368 engine behind a UI or another front end are encouraged to switch to
3369 using the GDB/MI interface, instead of the old annotations interface
3370 which is now deprecated.
3372 * Support for debugging Pascal programs.
3374 GDB now includes support for debugging Pascal programs. The following
3375 main features are supported:
3377 - Pascal-specific data types such as sets;
3379 - automatic recognition of Pascal sources based on file-name
3382 - Pascal-style display of data types, variables, and functions;
3384 - a Pascal expression parser.
3386 However, some important features are not yet supported.
3388 - Pascal string operations are not supported at all;
3390 - there are some problems with boolean types;
3392 - Pascal type hexadecimal constants are not supported
3393 because they conflict with the internal variables format;
3395 - support for Pascal objects and classes is not full yet;
3397 - unlike Pascal, GDB is case-sensitive for symbol names.
3399 * Changes in completion.
3401 Commands such as `shell', `run' and `set args', which pass arguments
3402 to inferior programs, now complete on file names, similar to what
3403 users expect at the shell prompt.
3405 Commands which accept locations, such as `disassemble', `print',
3406 `breakpoint', `until', etc. now complete on filenames as well as
3407 program symbols. Thus, if you type "break foob TAB", and the source
3408 files linked into the programs include `foobar.c', that file name will
3409 be one of the candidates for completion. However, file names are not
3410 considered for completion after you typed a colon that delimits a file
3411 name from a name of a function in that file, as in "break foo.c:bar".
3413 `set demangle-style' completes on available demangling styles.
3415 * New platform-independent commands:
3417 It is now possible to define a post-hook for a command as well as a
3418 hook that runs before the command. For more details, see the
3419 documentation of `hookpost' in the GDB manual.
3421 * Changes in GNU/Linux native debugging.
3423 Support for debugging multi-threaded programs has been completely
3424 revised for all platforms except m68k and sparc. You can now debug as
3425 many threads as your system allows you to have.
3427 Attach/detach is supported for multi-threaded programs.
3429 Support for SSE registers was added for x86. This doesn't work for
3430 multi-threaded programs though.
3432 * Changes in MIPS configurations.
3434 Multi-arch support is enabled for all MIPS configurations.
3436 GDB can now be built as native debugger on SGI Irix 6.x systems for
3437 debugging n32 executables. (Debugging 64-bit executables is not yet
3440 * Unified support for hardware watchpoints in all x86 configurations.
3442 Most (if not all) native x86 configurations support hardware-assisted
3443 breakpoints and watchpoints in a unified manner. This support
3444 implements debug register sharing between watchpoints, which allows to
3445 put a virtually infinite number of watchpoints on the same address,
3446 and also supports watching regions up to 16 bytes with several debug
3449 The new maintenance command `maintenance show-debug-regs' toggles
3450 debugging print-outs in functions that insert, remove, and test
3451 watchpoints and hardware breakpoints.
3453 * Changes in the DJGPP native configuration.
3455 New command ``info dos sysinfo'' displays assorted information about
3456 the CPU, OS, memory, and DPMI server.
3458 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3459 display information about segment descriptors stored in GDT, LDT, and
3462 New commands ``info dos pde'' and ``info dos pte'' display entries
3463 from Page Directory and Page Tables (for now works with CWSDPMI only).
3464 New command ``info dos address-pte'' displays the Page Table entry for
3465 a given linear address.
3467 GDB can now pass command lines longer than 126 characters to the
3468 program being debugged (requires an update to the libdbg.a library
3469 which is part of the DJGPP development kit).
3471 DWARF2 debug info is now supported.
3473 It is now possible to `step' and `next' through calls to `longjmp'.
3475 * Changes in documentation.
3477 All GDB documentation was converted to GFDL, the GNU Free
3478 Documentation License.
3480 Tracepoints-related commands are now fully documented in the GDB
3483 TUI, the Text-mode User Interface, is now documented in the manual.
3485 Tracepoints-related commands are now fully documented in the GDB
3488 The "GDB Internals" manual now has an index. It also includes
3489 documentation of `ui_out' functions, GDB coding standards, x86
3490 hardware watchpoints, and memory region attributes.
3492 * GDB's version number moved to ``version.in''
3494 The Makefile variable VERSION has been replaced by the file
3495 ``version.in''. People creating GDB distributions should update the
3496 contents of this file.
3500 GUD support is now a standard part of the EMACS distribution.
3502 *** Changes in GDB 5.0:
3504 * Improved support for debugging FP programs on x86 targets
3506 Unified and much-improved support for debugging floating-point
3507 programs on all x86 targets. In particular, ``info float'' now
3508 displays the FP registers in the same format on all x86 targets, with
3509 greater level of detail.
3511 * Improvements and bugfixes in hardware-assisted watchpoints
3513 It is now possible to watch array elements, struct members, and
3514 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3515 on x86 targets no longer erroneously trigger when the address is
3518 * Improvements in the native DJGPP version of GDB
3520 The distribution now includes all the scripts and auxiliary files
3521 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3522 machines ``out of the box''.
3524 The DJGPP version can now debug programs that use signals. It is
3525 possible to catch signals that happened in the debuggee, deliver
3526 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3527 would kill the program being debugged.) Programs that hook hardware
3528 interrupts (keyboard, timer, etc.) can also be debugged.
3530 It is now possible to debug DJGPP programs that redirect their
3531 standard handles or switch them to raw (as opposed to cooked) mode, or
3532 even close them. The command ``run < foo > bar'' works as expected,
3533 and ``info terminal'' reports useful information about the debuggee's
3534 terminal, including raw/cooked mode, redirection, etc.
3536 The DJGPP version now uses termios functions for console I/O, which
3537 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3540 DOS-style file names with drive letters are now fully supported by
3543 It is now possible to debug DJGPP programs that switch their working
3544 directory. It is also possible to rerun the debuggee any number of
3545 times without restarting GDB; thus, you can use the same setup,
3546 breakpoints, etc. for many debugging sessions.
3548 * New native configurations
3550 ARM GNU/Linux arm*-*-linux*
3551 PowerPC GNU/Linux powerpc-*-linux*
3555 Motorola MCore mcore-*-*
3556 x86 VxWorks i[3456]86-*-vxworks*
3557 PowerPC VxWorks powerpc-*-vxworks*
3558 TI TMS320C80 tic80-*-*
3560 * OBSOLETE configurations
3562 Altos 3068 m68*-altos-*
3563 Convex c1-*-*, c2-*-*
3565 ARM RISCix arm-*-* (as host)
3568 Configurations that have been declared obsolete will be commented out,
3569 but the code will be left in place. If there is no activity to revive
3570 these configurations before the next release of GDB, the sources will
3571 be permanently REMOVED.
3573 * Gould support removed
3575 Support for the Gould PowerNode and NP1 has been removed.
3577 * New features for SVR4
3579 On SVR4 native platforms (such as Solaris), if you attach to a process
3580 without first loading a symbol file, GDB will now attempt to locate and
3581 load symbols from the running process's executable file.
3583 * Many C++ enhancements
3585 C++ support has been greatly improved. Overload resolution now works properly
3586 in almost all cases. RTTI support is on the way.
3588 * Remote targets can connect to a sub-program
3590 A popen(3) style serial-device has been added. This device starts a
3591 sub-process (such as a stand-alone simulator) and then communicates
3592 with that. The sub-program to run is specified using the syntax
3593 ``|<program> <args>'' vis:
3595 (gdb) set remotedebug 1
3596 (gdb) target extended-remote |mn10300-elf-sim program-args
3598 * MIPS 64 remote protocol
3600 A long standing bug in the mips64 remote protocol where by GDB
3601 expected certain 32 bit registers (ex SR) to be transfered as 32
3602 instead of 64 bits has been fixed.
3604 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3605 added to provide backward compatibility with older versions of GDB.
3607 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3609 The command ``set remotebinarydownload'' command has been replaced by
3610 ``set remote X-packet''. Other commands in ``set remote'' family
3611 include ``set remote P-packet''.
3613 * Breakpoint commands accept ranges.
3615 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3616 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3617 ``tracepoint passcount'' also accepts a range of tracepoints.
3619 * ``apropos'' command added.
3621 The ``apropos'' command searches through command names and
3622 documentation strings, printing out matches, making it much easier to
3623 try to find a command that does what you are looking for.
3627 A new machine oriented interface (MI) has been added to GDB. This
3628 interface is designed for debug environments running GDB as a separate
3629 process. This is part of the long term libGDB project. See the
3630 "GDB/MI" chapter of the GDB manual for further information. It can be
3631 enabled by configuring with:
3633 .../configure --enable-gdbmi
3635 *** Changes in GDB-4.18:
3637 * New native configurations
3639 HP-UX 10.20 hppa*-*-hpux10.20
3640 HP-UX 11.x hppa*-*-hpux11.0*
3641 M68K GNU/Linux m68*-*-linux*
3645 Fujitsu FR30 fr30-*-elf*
3646 Intel StrongARM strongarm-*-*
3647 Mitsubishi D30V d30v-*-*
3649 * OBSOLETE configurations
3651 Gould PowerNode, NP1 np1-*-*, pn-*-*
3653 Configurations that have been declared obsolete will be commented out,
3654 but the code will be left in place. If there is no activity to revive
3655 these configurations before the next release of GDB, the sources will
3656 be permanently REMOVED.
3660 As a compatibility experiment, GDB's source files buildsym.h and
3661 buildsym.c have been converted to pure standard C, no longer
3662 containing any K&R compatibility code. We believe that all systems in
3663 use today either come with a standard C compiler, or have a GCC port
3664 available. If this is not true, please report the affected
3665 configuration to bug-gdb@gnu.org immediately. See the README file for
3666 information about getting a standard C compiler if you don't have one
3671 GDB now uses readline 2.2.
3673 * set extension-language
3675 You can now control the mapping between filename extensions and source
3676 languages by using the `set extension-language' command. For instance,
3677 you can ask GDB to treat .c files as C++ by saying
3678 set extension-language .c c++
3679 The command `info extensions' lists all of the recognized extensions
3680 and their associated languages.
3682 * Setting processor type for PowerPC and RS/6000
3684 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3685 you can use the `set processor' command to specify what variant of the
3686 PowerPC family you are debugging. The command
3690 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3691 following PowerPC and RS6000 variants:
3693 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3694 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3696 403GC IBM PowerPC 403GC
3697 505 Motorola PowerPC 505
3698 860 Motorola PowerPC 860 or 850
3699 601 Motorola PowerPC 601
3700 602 Motorola PowerPC 602
3701 603 Motorola/IBM PowerPC 603 or 603e
3702 604 Motorola PowerPC 604 or 604e
3703 750 Motorola/IBM PowerPC 750 or 750
3705 At the moment, this command just tells GDB what to name the
3706 special-purpose processor registers. Since almost all the affected
3707 registers are inaccessible to user-level programs, this command is
3708 only useful for remote debugging in its present form.
3712 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3713 more extensive support for HP-UX. Added features include shared
3714 library support, kernel threads and hardware watchpoints for 11.00,
3715 support for HP's ANSI C and C++ compilers, and a compatibility mode
3716 for xdb and dbx commands.
3720 HP's donation includes the new concept of catchpoints, which is a
3721 generalization of the old catch command. On HP-UX, it is now possible
3722 to catch exec, fork, and vfork, as well as library loading.
3724 This means that the existing catch command has changed; its first
3725 argument now specifies the type of catch to be set up. See the
3726 output of "help catch" for a list of catchpoint types.
3728 * Debugging across forks
3730 On HP-UX, you can choose which process to debug when a fork() happens
3735 HP has donated a curses-based terminal user interface (TUI). To get
3736 it, build with --enable-tui. Although this can be enabled for any
3737 configuration, at present it only works for native HP debugging.
3739 * GDB remote protocol additions
3741 A new protocol packet 'X' that writes binary data is now available.
3742 Default behavior is to try 'X', then drop back to 'M' if the stub
3743 fails to respond. The settable variable `remotebinarydownload'
3744 allows explicit control over the use of 'X'.
3746 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3747 full 64-bit address. The command
3749 set remoteaddresssize 32
3751 can be used to revert to the old behaviour. For existing remote stubs
3752 the change should not be noticed, as the additional address information
3755 In order to assist in debugging stubs, you may use the maintenance
3756 command `packet' to send any text string to the stub. For instance,
3758 maint packet heythere
3760 sends the packet "$heythere#<checksum>". Note that it is very easy to
3761 disrupt a debugging session by sending the wrong packet at the wrong
3764 The compare-sections command allows you to compare section data on the
3765 target to what is in the executable file without uploading or
3766 downloading, by comparing CRC checksums.
3768 * Tracing can collect general expressions
3770 You may now collect general expressions at tracepoints. This requires
3771 further additions to the target-side stub; see tracepoint.c and
3772 doc/agentexpr.texi for further details.
3774 * mask-address variable for Mips
3776 For Mips targets, you may control the zeroing of the upper 32 bits of
3777 a 64-bit address by entering `set mask-address on'. This is mainly
3778 of interest to users of embedded R4xxx and R5xxx processors.
3780 * Higher serial baud rates
3782 GDB's serial code now allows you to specify baud rates 57600, 115200,
3783 230400, and 460800 baud. (Note that your host system may not be able
3784 to achieve all of these rates.)
3788 The i960 configuration now includes an initial implementation of a
3789 builtin simulator, contributed by Jim Wilson.
3792 *** Changes in GDB-4.17:
3794 * New native configurations
3796 Alpha GNU/Linux alpha*-*-linux*
3797 Unixware 2.x i[3456]86-unixware2*
3798 Irix 6.x mips*-sgi-irix6*
3799 PowerPC GNU/Linux powerpc-*-linux*
3800 PowerPC Solaris powerpcle-*-solaris*
3801 Sparc GNU/Linux sparc-*-linux*
3802 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3806 Argonaut Risc Chip (ARC) arc-*-*
3807 Hitachi H8/300S h8300*-*-*
3808 Matsushita MN10200 w/simulator mn10200-*-*
3809 Matsushita MN10300 w/simulator mn10300-*-*
3810 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3811 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3812 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3813 Mitsubishi D10V w/simulator d10v-*-*
3814 Mitsubishi M32R/D w/simulator m32r-*-elf*
3815 Tsqware Sparclet sparclet-*-*
3816 NEC V850 w/simulator v850-*-*
3818 * New debugging protocols
3820 ARM with RDI protocol arm*-*-*
3821 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3822 DDB and LSI variants of PMON protocol mips*-*-*
3823 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3824 PowerPC with SDS protocol powerpc{,le}-*-eabi
3825 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3829 All configurations can now understand and use the DWARF 2 debugging
3830 format. The choice is automatic, if the symbol file contains DWARF 2
3835 GDB now includes basic Java language support. This support is
3836 only useful with Java compilers that produce native machine code.
3838 * solib-absolute-prefix and solib-search-path
3840 For SunOS and SVR4 shared libraries, you may now set the prefix for
3841 loading absolute shared library symbol files, and the search path for
3842 locating non-absolute shared library symbol files.
3844 * Live range splitting
3846 GDB can now effectively debug code for which GCC has performed live
3847 range splitting as part of its optimization. See gdb/doc/LRS for
3848 more details on the expected format of the stabs information.
3852 GDB's support for the GNU Hurd, including thread debugging, has been
3853 updated to work with current versions of the Hurd.
3857 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3858 instruction set. ARM GDB automatically detects when Thumb
3859 instructions are in use, and adjusts disassembly and backtracing
3864 GDB's MIPS target configurations now handle the MIP16 16-bit
3869 GDB now includes support for overlays; if an executable has been
3870 linked such that multiple sections are based at the same address, GDB
3871 will decide which section to use for symbolic info. You can choose to
3872 control the decision manually, using overlay commands, or implement
3873 additional target-side support and use "overlay load-target" to bring
3874 in the overlay mapping. Do "help overlay" for more detail.
3878 The command "info symbol <address>" displays information about
3879 the symbol at the specified address.
3883 The standard remote protocol now includes an extension that allows
3884 asynchronous collection and display of trace data. This requires
3885 extensive support in the target-side debugging stub. Tracing mode
3886 includes a new interaction mode in GDB and new commands: see the
3887 file tracepoint.c for more details.
3891 Configurations for embedded MIPS now include a simulator contributed
3892 by Cygnus Solutions. The simulator supports the instruction sets
3893 of most MIPS variants.
3897 Sparc configurations may now include the ERC32 simulator contributed
3898 by the European Space Agency. The simulator is not built into
3899 Sparc targets by default; configure with --enable-sim to include it.
3903 For target configurations that may include multiple variants of a
3904 basic architecture (such as MIPS and SH), you may now set the
3905 architecture explicitly. "set arch" sets, "info arch" lists
3906 the possible architectures.
3908 *** Changes in GDB-4.16:
3910 * New native configurations
3912 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3913 M68K NetBSD m68k-*-netbsd*
3914 PowerPC AIX 4.x powerpc-*-aix*
3915 PowerPC MacOS powerpc-*-macos*
3916 PowerPC Windows NT powerpcle-*-cygwin32
3917 RS/6000 AIX 4.x rs6000-*-aix4*
3921 ARM with RDP protocol arm-*-*
3922 I960 with MON960 i960-*-coff
3923 MIPS VxWorks mips*-*-vxworks*
3924 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3925 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3927 Matra Sparclet sparclet-*-*
3931 The powerpc-eabi configuration now includes the PSIM simulator,
3932 contributed by Andrew Cagney, with assistance from Mike Meissner.
3933 PSIM is a very elaborate model of the PowerPC, including not only
3934 basic instruction set execution, but also details of execution unit
3935 performance and I/O hardware. See sim/ppc/README for more details.
3939 GDB now works with Solaris 2.5.
3941 * Windows 95/NT native
3943 GDB will now work as a native debugger on Windows 95 and Windows NT.
3944 To build it from source, you must use the "gnu-win32" environment,
3945 which uses a DLL to emulate enough of Unix to run the GNU tools.
3946 Further information, binaries, and sources are available at
3947 ftp.cygnus.com, under pub/gnu-win32.
3949 * dont-repeat command
3951 If a user-defined command includes the command `dont-repeat', then the
3952 command will not be repeated if the user just types return. This is
3953 useful if the command is time-consuming to run, so that accidental
3954 extra keystrokes don't run the same command many times.
3956 * Send break instead of ^C
3958 The standard remote protocol now includes an option to send a break
3959 rather than a ^C to the target in order to interrupt it. By default,
3960 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3962 * Remote protocol timeout
3964 The standard remote protocol includes a new variable `remotetimeout'
3965 that allows you to set the number of seconds before GDB gives up trying
3966 to read from the target. The default value is 2.
3968 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3970 By default GDB will automatically keep track of objects as they are
3971 loaded and unloaded by the dynamic linker. By using the command `set
3972 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3973 when shared library events occur, thus allowing you to set breakpoints
3974 in shared libraries which are explicitly loaded by the inferior.
3976 Note this feature does not work on hpux8. On hpux9 you must link
3977 /usr/lib/end.o into your program. This feature should work
3978 automatically on hpux10.
3980 * Irix 5.x hardware watchpoint support
3982 Irix 5 configurations now support the use of hardware watchpoints.
3984 * Mips protocol "SYN garbage limit"
3986 When debugging a Mips target using the `target mips' protocol, you
3987 may set the number of characters that GDB will ignore by setting
3988 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3989 every character. The default value is 1050.
3991 * Recording and replaying remote debug sessions
3993 If you set `remotelogfile' to the name of a file, gdb will write to it
3994 a recording of a remote debug session. This recording may then be
3995 replayed back to gdb using "gdbreplay". See gdbserver/README for
3996 details. This is useful when you have a problem with GDB while doing
3997 remote debugging; you can make a recording of the session and send it
3998 to someone else, who can then recreate the problem.
4000 * Speedups for remote debugging
4002 GDB includes speedups for downloading and stepping MIPS systems using
4003 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4004 and more efficient S-record downloading.
4006 * Memory use reductions and statistics collection
4008 GDB now uses less memory and reports statistics about memory usage.
4009 Try the `maint print statistics' command, for example.
4011 *** Changes in GDB-4.15:
4013 * Psymtabs for XCOFF
4015 The symbol reader for AIX GDB now uses partial symbol tables. This
4016 can greatly improve startup time, especially for large executables.
4018 * Remote targets use caching
4020 Remote targets now use a data cache to speed up communication with the
4021 remote side. The data cache could lead to incorrect results because
4022 it doesn't know about volatile variables, thus making it impossible to
4023 debug targets which use memory mapped I/O devices. `set remotecache
4024 off' turns the the data cache off.
4026 * Remote targets may have threads
4028 The standard remote protocol now includes support for multiple threads
4029 in the target system, using new protocol commands 'H' and 'T'. See
4030 gdb/remote.c for details.
4034 If GDB is configured with `--enable-netrom', then it will include
4035 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4036 acts as though it is a bank of ROM on the target board, but you can
4037 write into it over the network. GDB's support consists only of
4038 support for fast loading into the emulated ROM; to debug, you must use
4039 another protocol, such as standard remote protocol. The usual
4040 sequence is something like
4042 target nrom <netrom-hostname>
4044 target remote <netrom-hostname>:1235
4048 GDB now includes support for the Apple Macintosh, as a host only. It
4049 may be run as either an MPW tool or as a standalone application, and
4050 it can debug through the serial port. All the usual GDB commands are
4051 available, but to the target command, you must supply "serial" as the
4052 device type instead of "/dev/ttyXX". See mpw-README in the main
4053 directory for more information on how to build. The MPW configuration
4054 scripts */mpw-config.in support only a few targets, and only the
4055 mips-idt-ecoff target has been tested.
4059 GDB configuration now uses autoconf. This is not user-visible,
4060 but does simplify configuration and building.
4064 GDB now supports hpux10.
4066 *** Changes in GDB-4.14:
4068 * New native configurations
4070 x86 FreeBSD i[345]86-*-freebsd
4071 x86 NetBSD i[345]86-*-netbsd
4072 NS32k NetBSD ns32k-*-netbsd
4073 Sparc NetBSD sparc-*-netbsd
4077 A29K VxWorks a29k-*-vxworks
4078 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4079 CPU32 EST-300 emulator m68*-*-est*
4080 PowerPC ELF powerpc-*-elf
4083 * Alpha OSF/1 support for procfs
4085 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4086 possible to attach to running processes. As the mounting of the /proc
4087 filesystem is optional on the Alpha, GDB automatically determines
4088 the availability of /proc during startup. This can lead to problems
4089 if /proc is unmounted after GDB has been started.
4091 * Arguments to user-defined commands
4093 User commands may accept up to 10 arguments separated by whitespace.
4094 Arguments are accessed within the user command via $arg0..$arg9. A
4097 print $arg0 + $arg1 + $arg2
4099 To execute the command use:
4102 Defines the command "adder" which prints the sum of its three arguments.
4103 Note the arguments are text substitutions, so they may reference variables,
4104 use complex expressions, or even perform inferior function calls.
4106 * New `if' and `while' commands
4108 This makes it possible to write more sophisticated user-defined
4109 commands. Both commands take a single argument, which is the
4110 expression to evaluate, and must be followed by the commands to
4111 execute, one per line, if the expression is nonzero, the list being
4112 terminated by the word `end'. The `if' command list may include an
4113 `else' word, which causes the following commands to be executed only
4114 if the expression is zero.
4116 * Fortran source language mode
4118 GDB now includes partial support for Fortran 77. It will recognize
4119 Fortran programs and can evaluate a subset of Fortran expressions, but
4120 variables and functions may not be handled correctly. GDB will work
4121 with G77, but does not yet know much about symbols emitted by other
4124 * Better HPUX support
4126 Most debugging facilities now work on dynamic executables for HPPAs
4127 running hpux9 or later. You can attach to running dynamically linked
4128 processes, but by default the dynamic libraries will be read-only, so
4129 for instance you won't be able to put breakpoints in them. To change
4130 that behavior do the following before running the program:
4136 This will cause the libraries to be mapped private and read-write.
4137 To revert to the normal behavior, do this:
4143 You cannot set breakpoints or examine data in the library until after
4144 the library is loaded if the function/data symbols do not have
4147 GDB can now also read debug symbols produced by the HP C compiler on
4148 HPPAs (sorry, no C++, Fortran or 68k support).
4150 * Target byte order now dynamically selectable
4152 You can choose which byte order to use with a target system, via the
4153 commands "set endian big" and "set endian little", and you can see the
4154 current setting by using "show endian". You can also give the command
4155 "set endian auto", in which case GDB will use the byte order
4156 associated with the executable. Currently, only embedded MIPS
4157 configurations support dynamic selection of target byte order.
4159 * New DOS host serial code
4161 This version uses DPMI interrupts to handle buffered I/O, so you
4162 no longer need to run asynctsr when debugging boards connected to
4165 *** Changes in GDB-4.13:
4167 * New "complete" command
4169 This lists all the possible completions for the rest of the line, if it
4170 were to be given as a command itself. This is intended for use by emacs.
4172 * Trailing space optional in prompt
4174 "set prompt" no longer adds a space for you after the prompt you set. This
4175 allows you to set a prompt which ends in a space or one that does not.
4177 * Breakpoint hit counts
4179 "info break" now displays a count of the number of times the breakpoint
4180 has been hit. This is especially useful in conjunction with "ignore"; you
4181 can ignore a large number of breakpoint hits, look at the breakpoint info
4182 to see how many times the breakpoint was hit, then run again, ignoring one
4183 less than that number, and this will get you quickly to the last hit of
4186 * Ability to stop printing at NULL character
4188 "set print null-stop" will cause GDB to stop printing the characters of
4189 an array when the first NULL is encountered. This is useful when large
4190 arrays actually contain only short strings.
4192 * Shared library breakpoints
4194 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4195 breakpoints in shared libraries before the executable is run.
4197 * Hardware watchpoints
4199 There is a new hardware breakpoint for the watch command for sparclite
4200 targets. See gdb/sparclite/hw_breakpoint.note.
4202 Hardware watchpoints are also now supported under GNU/Linux.
4206 Annotations have been added. These are for use with graphical interfaces,
4207 and are still experimental. Currently only gdba.el uses these.
4209 * Improved Irix 5 support
4211 GDB now works properly with Irix 5.2.
4213 * Improved HPPA support
4215 GDB now works properly with the latest GCC and GAS.
4217 * New native configurations
4219 Sequent PTX4 i[34]86-sequent-ptx4
4220 HPPA running OSF/1 hppa*-*-osf*
4221 Atari TT running SVR4 m68*-*-sysv4*
4222 RS/6000 LynxOS rs6000-*-lynxos*
4226 OS/9000 i[34]86-*-os9k
4227 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4230 * Hitachi SH7000 and E7000-PC ICE support
4232 There is now support for communicating with the Hitachi E7000-PC ICE.
4233 This is available automatically when GDB is configured for the SH.
4237 As usual, a variety of small fixes and improvements, both generic
4238 and configuration-specific. See the ChangeLog for more detail.
4240 *** Changes in GDB-4.12:
4242 * Irix 5 is now supported
4246 GDB-4.12 on the HPPA has a number of changes which make it unable
4247 to debug the output from the currently released versions of GCC and
4248 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4249 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4250 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4253 *** Changes in GDB-4.11:
4255 * User visible changes:
4259 The "set remotedebug" option is now consistent between the mips remote
4260 target, remote targets using the gdb-specific protocol, UDI (AMD's
4261 debug protocol for the 29k) and the 88k bug monitor. It is now an
4262 integer specifying a debug level (normally 0 or 1, but 2 means more
4263 debugging info for the mips target).
4265 * DEC Alpha native support
4267 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4268 debug info, but GDB works fairly well with the DEC compiler and should
4269 work with a future GCC release. See the README file for a few
4270 Alpha-specific notes.
4272 * Preliminary thread implementation
4274 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4276 * LynxOS native and target support for 386
4278 This release has been hosted on LynxOS 2.2, and also can be configured
4279 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4282 * Improvements in C++ mangling/demangling.
4284 This release has much better g++ debugging, specifically in name
4285 mangling/demangling, virtual function calls, print virtual table,
4286 call methods, ...etc.
4288 *** Changes in GDB-4.10:
4290 * User visible changes:
4292 Remote debugging using the GDB-specific (`target remote') protocol now
4293 supports the `load' command. This is only useful if you have some
4294 other way of getting the stub to the target system, and you can put it
4295 somewhere in memory where it won't get clobbered by the download.
4297 Filename completion now works.
4299 When run under emacs mode, the "info line" command now causes the
4300 arrow to point to the line specified. Also, "info line" prints
4301 addresses in symbolic form (as well as hex).
4303 All vxworks based targets now support a user settable option, called
4304 vxworks-timeout. This option represents the number of seconds gdb
4305 should wait for responses to rpc's. You might want to use this if
4306 your vxworks target is, perhaps, a slow software simulator or happens
4307 to be on the far side of a thin network line.
4311 This release contains support for using a DEC alpha as a GDB host for
4312 cross debugging. Native alpha debugging is not supported yet.
4315 *** Changes in GDB-4.9:
4319 This is the first GDB release which is accompanied by a matching testsuite.
4320 The testsuite requires installation of dejagnu, which should be available
4321 via ftp from most sites that carry GNU software.
4325 'Cfront' style demangling has had its name changed to 'ARM' style, to
4326 emphasize that it was written from the specifications in the C++ Annotated
4327 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4328 disclaimers, it still generated too much confusion with users attempting to
4329 use gdb with AT&T cfront.
4333 GDB now uses a standard remote interface to a simulator library.
4334 So far, the library contains simulators for the Zilog Z8001/2, the
4335 Hitachi H8/300, H8/500 and Super-H.
4337 * New targets supported
4339 H8/300 simulator h8300-hitachi-hms or h8300hms
4340 H8/500 simulator h8500-hitachi-hms or h8500hms
4341 SH simulator sh-hitachi-hms or sh
4342 Z8000 simulator z8k-zilog-none or z8ksim
4343 IDT MIPS board over serial line mips-idt-ecoff
4345 Cross-debugging to GO32 targets is supported. It requires a custom
4346 version of the i386-stub.c module which is integrated with the
4347 GO32 memory extender.
4349 * New remote protocols
4351 MIPS remote debugging protocol.
4353 * New source languages supported
4355 This version includes preliminary support for Chill, a Pascal like language
4356 used by telecommunications companies. Chill support is also being integrated
4357 into the GNU compiler, but we don't know when it will be publically available.
4360 *** Changes in GDB-4.8:
4362 * HP Precision Architecture supported
4364 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4365 version of this support was available as a set of patches from the
4366 University of Utah. GDB does not support debugging of programs
4367 compiled with the HP compiler, because HP will not document their file
4368 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4369 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4371 Many problems in the preliminary version have been fixed.
4373 * Faster and better demangling
4375 We have improved template demangling and fixed numerous bugs in the GNU style
4376 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4377 character types (wchar_t) are now supported. Demangling of each symbol is now
4378 only done once, and is cached when the symbol table for a file is read in.
4379 This results in a small increase in memory usage for C programs, a moderate
4380 increase in memory usage for C++ programs, and a fantastic speedup in
4383 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4384 from the specifications in the Annotated Reference Manual, which AT&T's
4385 compiler does not actually implement.
4387 * G++ multiple inheritance compiler problem
4389 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4390 inheritance lattices was reworked to properly discover ambiguities. We
4391 recently found an example which causes this new algorithm to fail in a
4392 very subtle way, producing bad debug information for those classes.
4393 The file 'gcc.patch' (in this directory) can be applied to gcc to
4394 circumvent the problem. A future GCC release will contain a complete
4397 The previous G++ debug info problem (mentioned below for the gdb-4.7
4398 release) is fixed in gcc version 2.3.2.
4400 * Improved configure script
4402 The `configure' script will now attempt to guess your system type if
4403 you don't supply a host system type. The old scheme of supplying a
4404 host system triplet is preferable over using this. All the magic is
4405 done in the new `config.guess' script. Examine it for details.
4407 We have also brought our configure script much more in line with the FSF's
4408 version. It now supports the --with-xxx options. In particular,
4409 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4410 The resulting GDB will not be able to read arbitrary object file formats --
4411 only the format ``expected'' to be used on the configured target system.
4412 We hope to make this the default in a future release.
4414 * Documentation improvements
4416 There's new internal documentation on how to modify GDB, and how to
4417 produce clean changes to the code. We implore people to read it
4418 before submitting changes.
4420 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4421 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4422 `info' files are also provided. To build `info' files from scratch,
4423 you will need the latest `makeinfo' release, which will be available in
4424 a future texinfo-X.Y release.
4426 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4427 We're not sure exactly which versions have this problem, but it has
4428 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4429 or better. If that isn't possible, there is a patch in
4430 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4431 around this problem.
4435 GDB now supports array constants that can be used in expressions typed in by
4436 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4437 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4440 The new directory `gdb/sparclite' contains a program that demonstrates
4441 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4443 * New native hosts supported
4445 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4446 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4448 * New targets supported
4450 AMD 29k family via UDI a29k-amd-udi or udi29k
4452 * New file formats supported
4454 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4455 HPUX core files, and SCO 3.2v2 core files.
4459 Attaching to processes now works again; thanks for the many bug reports.
4461 We have also stomped on a bunch of core dumps caused by
4462 printf_filtered("%s") problems.
4464 We eliminated a copyright problem on the rpc and ptrace header files
4465 for VxWorks, which was discovered at the last minute during the 4.7
4466 release. You should now be able to build a VxWorks GDB.
4468 You can now interrupt gdb while an attached process is running. This
4469 will cause the attached process to stop, and give control back to GDB.
4471 We fixed problems caused by using too many file descriptors
4472 for reading symbols from object files and libraries. This was
4473 especially a problem for programs that used many (~100) shared
4476 The `step' command now only enters a subroutine if there is line number
4477 information for the subroutine. Otherwise it acts like the `next'
4478 command. Previously, `step' would enter subroutines if there was
4479 any debugging information about the routine. This avoids problems
4480 when using `cc -g1' on MIPS machines.
4482 * Internal improvements
4484 GDB's internal interfaces have been improved to make it easier to support
4485 debugging of multiple languages in the future.
4487 GDB now uses a common structure for symbol information internally.
4488 Minimal symbols (derived from linkage symbols in object files), partial
4489 symbols (from a quick scan of debug information), and full symbols
4490 contain a common subset of information, making it easier to write
4491 shared code that handles any of them.
4493 * New command line options
4495 We now accept --silent as an alias for --quiet.
4499 The memory-mapped-malloc library is now licensed under the GNU Library
4500 General Public License.
4502 *** Changes in GDB-4.7:
4504 * Host/native/target split
4506 GDB has had some major internal surgery to untangle the support for
4507 hosts and remote targets. Now, when you configure GDB for a remote
4508 target, it will no longer load in all of the support for debugging
4509 local programs on the host. When fully completed and tested, this will
4510 ensure that arbitrary host/target combinations are possible.
4512 The primary conceptual shift is to separate the non-portable code in
4513 GDB into three categories. Host specific code is required any time GDB
4514 is compiled on that host, regardless of the target. Target specific
4515 code relates to the peculiarities of the target, but can be compiled on
4516 any host. Native specific code is everything else: it can only be
4517 built when the host and target are the same system. Child process
4518 handling and core file support are two common `native' examples.
4520 GDB's use of /proc for controlling Unix child processes is now cleaner.
4521 It has been split out into a single module under the `target_ops' vector,
4522 plus two native-dependent functions for each system that uses /proc.
4524 * New hosts supported
4526 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4527 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4528 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4530 * New targets supported
4532 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4533 68030 and CPU32 m68030-*-*, m68332-*-*
4535 * New native hosts supported
4537 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4538 (386bsd is not well tested yet)
4539 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4541 * New file formats supported
4543 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4544 supports reading of `a.out.adobe' object files, which are an a.out
4545 format extended with minimal information about multiple sections.
4549 `show copying' is the same as the old `info copying'.
4550 `show warranty' is the same as `info warrantee'.
4551 These were renamed for consistency. The old commands continue to work.
4553 `info handle' is a new alias for `info signals'.
4555 You can now define pre-command hooks, which attach arbitrary command
4556 scripts to any command. The commands in the hook will be executed
4557 prior to the user's command. You can also create a hook which will be
4558 executed whenever the program stops. See gdb.texinfo.
4562 We now deal with Cfront style name mangling, and can even extract type
4563 info from mangled symbols. GDB can automatically figure out which
4564 symbol mangling style your C++ compiler uses.
4566 Calling of methods and virtual functions has been improved as well.
4570 The crash that occured when debugging Sun Ansi-C compiled binaries is
4571 fixed. This was due to mishandling of the extra N_SO stabs output
4574 We also finally got Ultrix 4.2 running in house, and fixed core file
4575 support, with help from a dozen people on the net.
4577 John M. Farrell discovered that the reason that single-stepping was so
4578 slow on all of the Mips based platforms (primarily SGI and DEC) was
4579 that we were trying to demangle and lookup a symbol used for internal
4580 purposes on every instruction that was being stepped through. Changing
4581 the name of that symbol so that it couldn't be mistaken for a C++
4582 mangled symbol sped things up a great deal.
4584 Rich Pixley sped up symbol lookups in general by getting much smarter
4585 about when C++ symbol mangling is necessary. This should make symbol
4586 completion (TAB on the command line) much faster. It's not as fast as
4587 we'd like, but it's significantly faster than gdb-4.6.
4591 A new user controllable variable 'call_scratch_address' can
4592 specify the location of a scratch area to be used when GDB
4593 calls a function in the target. This is necessary because the
4594 usual method of putting the scratch area on the stack does not work
4595 in systems that have separate instruction and data spaces.
4597 We integrated changes to support the 29k UDI (Universal Debugger
4598 Interface), but discovered at the last minute that we didn't have all
4599 of the appropriate copyright paperwork. We are working with AMD to
4600 resolve this, and hope to have it available soon.
4604 We have sped up the remote serial line protocol, especially for targets
4605 with lots of registers. It now supports a new `expedited status' ('T')
4606 message which can be used in place of the existing 'S' status message.
4607 This allows the remote stub to send only the registers that GDB
4608 needs to make a quick decision about single-stepping or conditional
4609 breakpoints, eliminating the need to fetch the entire register set for
4610 each instruction being stepped through.
4612 The GDB remote serial protocol now implements a write-through cache for
4613 registers, only re-reading the registers if the target has run.
4615 There is also a new remote serial stub for SPARC processors. You can
4616 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4617 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4618 processor with a serial port.
4622 Configure.in files have become much easier to read and modify. A new
4623 `table driven' format makes it more obvious what configurations are
4624 supported, and what files each one uses.
4628 There is a new opcodes library which will eventually contain all of the
4629 disassembly routines and opcode tables. At present, it only contains
4630 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4631 disassembler (binutils/objdump) to share these routines.
4633 The libiberty library is now copylefted under the GNU Library General
4634 Public License. This allows more liberal use, and was done so libg++
4635 can use it. This makes no difference to GDB, since the Library License
4636 grants all the rights from the General Public License.
4640 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4641 reference to the stabs symbol info used by the debugger. It is (as far
4642 as we know) the only published document on this fascinating topic. We
4643 encourage you to read it, compare it to the stabs information on your
4644 system, and send improvements on the document in general (to
4645 bug-gdb@prep.ai.mit.edu).
4647 And, of course, many bugs have been fixed.
4650 *** Changes in GDB-4.6:
4652 * Better support for C++ function names
4654 GDB now accepts as input the "demangled form" of C++ overloaded function
4655 names and member function names, and can do command completion on such names
4656 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4657 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4658 Make use of command completion, it is your friend.
4660 GDB also now accepts a variety of C++ mangled symbol formats. They are
4661 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4662 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4663 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4664 for the list of formats.
4666 * G++ symbol mangling problem
4668 Recent versions of gcc have a bug in how they emit debugging information for
4669 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4670 directory) can be applied to gcc to fix the problem. Alternatively, if you
4671 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4672 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4673 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4676 * New 'maintenance' command
4678 All of the commands related to hacking GDB internals have been moved out of
4679 the main command set, and now live behind the 'maintenance' command. This
4680 can also be abbreviated as 'mt'. The following changes were made:
4682 dump-me -> maintenance dump-me
4683 info all-breakpoints -> maintenance info breakpoints
4684 printmsyms -> maintenance print msyms
4685 printobjfiles -> maintenance print objfiles
4686 printpsyms -> maintenance print psymbols
4687 printsyms -> maintenance print symbols
4689 The following commands are new:
4691 maintenance demangle Call internal GDB demangler routine to
4692 demangle a C++ link name and prints the result.
4693 maintenance print type Print a type chain for a given symbol
4695 * Change to .gdbinit file processing
4697 We now read the $HOME/.gdbinit file before processing the argv arguments
4698 (e.g. reading symbol files or core files). This allows global parameters to
4699 be set, which will apply during the symbol reading. The ./.gdbinit is still
4700 read after argv processing.
4702 * New hosts supported
4704 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4706 GNU/Linux support i386-unknown-linux or linux
4708 We are also including code to support the HP/PA running BSD and HPUX. This
4709 is almost guaranteed not to work, as we didn't have time to test or build it
4710 for this release. We are including it so that the more adventurous (or
4711 masochistic) of you can play with it. We also had major problems with the
4712 fact that the compiler that we got from HP doesn't support the -g option.
4715 * New targets supported
4717 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4719 * More smarts about finding #include files
4721 GDB now remembers the compilation directory for all include files, and for
4722 all files from which C is generated (like yacc and lex sources). This
4723 greatly improves GDB's ability to find yacc/lex sources, and include files,
4724 especially if you are debugging your program from a directory different from
4725 the one that contains your sources.
4727 We also fixed a bug which caused difficulty with listing and setting
4728 breakpoints in include files which contain C code. (In the past, you had to
4729 try twice in order to list an include file that you hadn't looked at before.)
4731 * Interesting infernals change
4733 GDB now deals with arbitrary numbers of sections, where the symbols for each
4734 section must be relocated relative to that section's landing place in the
4735 target's address space. This work was needed to support ELF with embedded
4736 stabs used by Solaris-2.0.
4738 * Bug fixes (of course!)
4740 There have been loads of fixes for the following things:
4741 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4742 i960, stabs, DOS(GO32), procfs, etc...
4744 See the ChangeLog for details.
4746 *** Changes in GDB-4.5:
4748 * New machines supported (host and target)
4750 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4752 SGI Irix-4.x mips-sgi-irix4 or iris4
4754 * New malloc package
4756 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4757 Mmalloc is capable of handling mutiple heaps of memory. It is also
4758 capable of saving a heap to a file, and then mapping it back in later.
4759 This can be used to greatly speedup the startup of GDB by using a
4760 pre-parsed symbol table which lives in a mmalloc managed heap. For
4761 more details, please read mmalloc/mmalloc.texi.
4765 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4766 'help info proc' for details.
4768 * MIPS ecoff symbol table format
4770 The code that reads MIPS symbol table format is now supported on all hosts.
4771 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4774 * File name changes for MS-DOS
4776 Many files in the config directories have been renamed to make it easier to
4777 support GDB on MS-DOSe systems (which have very restrictive file name
4778 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4779 environment) is close to working but has some remaining problems. Note
4780 that debugging of DOS programs is not supported, due to limitations
4781 in the ``operating system'', but it can be used to host cross-debugging.
4783 * Cross byte order fixes
4785 Many fixes have been made to support cross debugging of Sparc and MIPS
4786 targets from hosts whose byte order differs.
4788 * New -mapped and -readnow options
4790 If memory-mapped files are available on your system through the 'mmap'
4791 system call, you can use the -mapped option on the `file' or
4792 `symbol-file' commands to cause GDB to write the symbols from your
4793 program into a reusable file. If the program you are debugging is
4794 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4795 Future GDB debugging sessions will notice the presence of this file,
4796 and will quickly map in symbol information from it, rather than reading
4797 the symbol table from the executable program. Using the '-mapped'
4798 option in a GDB `file' or `symbol-file' command has the same effect as
4799 starting GDB with the '-mapped' command-line option.
4801 You can cause GDB to read the entire symbol table immediately by using
4802 the '-readnow' option with any of the commands that load symbol table
4803 information (or on the GDB command line). This makes the command
4804 slower, but makes future operations faster.
4806 The -mapped and -readnow options are typically combined in order to
4807 build a `fred.syms' file that contains complete symbol information.
4808 A simple GDB invocation to do nothing but build a `.syms' file for future
4811 gdb -batch -nx -mapped -readnow programname
4813 The `.syms' file is specific to the host machine on which GDB is run.
4814 It holds an exact image of GDB's internal symbol table. It cannot be
4815 shared across multiple host platforms.
4817 * longjmp() handling
4819 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4820 siglongjmp() without losing control. This feature has not yet been ported to
4821 all systems. It currently works on many 386 platforms, all MIPS-based
4822 platforms (SGI, DECstation, etc), and Sun3/4.
4826 Preliminary work has been put in to support the new Solaris OS from Sun. At
4827 this time, it can control and debug processes, but it is not capable of
4832 As always, many many bug fixes. The major areas were with g++, and mipsread.
4833 People using the MIPS-based platforms should experience fewer mysterious
4834 crashes and trashed symbol tables.
4836 *** Changes in GDB-4.4:
4838 * New machines supported (host and target)
4840 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4842 BSD Reno on Vax vax-dec-bsd
4843 Ultrix on Vax vax-dec-ultrix
4845 * New machines supported (target)
4847 AMD 29000 embedded, using EBMON a29k-none-none
4851 GDB continues to improve its handling of C++. `References' work better.
4852 The demangler has also been improved, and now deals with symbols mangled as
4853 per the Annotated C++ Reference Guide.
4855 GDB also now handles `stabs' symbol information embedded in MIPS
4856 `ecoff' symbol tables. Since the ecoff format was not easily
4857 extensible to handle new languages such as C++, this appeared to be a
4858 good way to put C++ debugging info into MIPS binaries. This option
4859 will be supported in the GNU C compiler, version 2, when it is
4862 * New features for SVR4
4864 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4865 shared libraries. Debugging dynamically linked programs should present
4866 only minor differences from debugging statically linked programs.
4868 The `info proc' command will print out information about any process
4869 on an SVR4 system (including the one you are debugging). At the moment,
4870 it prints the address mappings of the process.
4872 If you bring up GDB on another SVR4 system, please send mail to
4873 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4875 * Better dynamic linking support in SunOS
4877 Reading symbols from shared libraries which contain debugging symbols
4878 now works properly. However, there remain issues such as automatic
4879 skipping of `transfer vector' code during function calls, which
4880 make it harder to debug code in a shared library, than to debug the
4881 same code linked statically.
4885 GDB is now using the latest `getopt' routines from the FSF. This
4886 version accepts the -- prefix for options with long names. GDB will
4887 continue to accept the old forms (-option and +option) as well.
4888 Various single letter abbreviations for options have been explicity
4889 added to the option table so that they won't get overshadowed in the
4890 future by other options that begin with the same letter.
4894 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4895 Many assorted bugs have been handled. Many more remain to be handled.
4896 See the various ChangeLog files (primarily in gdb and bfd) for details.
4899 *** Changes in GDB-4.3:
4901 * New machines supported (host and target)
4903 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4904 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4905 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4907 * Almost SCO Unix support
4909 We had hoped to support:
4910 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4911 (except for core file support), but we discovered very late in the release
4912 that it has problems with process groups that render gdb unusable. Sorry
4913 about that. I encourage people to fix it and post the fixes.
4915 * Preliminary ELF and DWARF support
4917 GDB can read ELF object files on System V Release 4, and can handle
4918 debugging records for C, in DWARF format, in ELF files. This support
4919 is preliminary. If you bring up GDB on another SVR4 system, please
4920 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4925 GDB now uses the latest `readline' library. One user-visible change
4926 is that two tabs will list possible command completions, which previously
4927 required typing M-? (meta-question mark, or ESC ?).
4931 The `stepi' bug that many of you noticed has been squashed.
4932 Many bugs in C++ have been handled. Many more remain to be handled.
4933 See the various ChangeLog files (primarily in gdb and bfd) for details.
4935 * State of the MIPS world (in case you wondered):
4937 GDB can understand the symbol tables emitted by the compilers
4938 supplied by most vendors of MIPS-based machines, including DEC. These
4939 symbol tables are in a format that essentially nobody else uses.
4941 Some versions of gcc come with an assembler post-processor called
4942 mips-tfile. This program is required if you want to do source-level
4943 debugging of gcc-compiled programs. I believe FSF does not ship
4944 mips-tfile with gcc version 1, but it will eventually come with gcc
4947 Debugging of g++ output remains a problem. g++ version 1.xx does not
4948 really support it at all. (If you're lucky, you should be able to get
4949 line numbers and stack traces to work, but no parameters or local
4950 variables.) With some work it should be possible to improve the
4953 When gcc version 2 is released, you will have somewhat better luck.
4954 However, even then you will get confusing results for inheritance and
4957 We will eventually provide full debugging of g++ output on
4958 DECstations. This will probably involve some kind of stabs-in-ecoff
4959 encapulation, but the details have not been worked out yet.
4962 *** Changes in GDB-4.2:
4964 * Improved configuration
4966 Only one copy of `configure' exists now, and it is not self-modifying.
4967 Porting BFD is simpler.
4971 The `step' and `next' commands now only stop at the first instruction
4972 of a source line. This prevents the multiple stops that used to occur
4973 in switch statements, for-loops, etc. `Step' continues to stop if a
4974 function that has debugging information is called within the line.
4978 Lots of small bugs fixed. More remain.
4980 * New host supported (not target)
4982 Intel 386 PC clone running Mach i386-none-mach
4985 *** Changes in GDB-4.1:
4987 * Multiple source language support
4989 GDB now has internal scaffolding to handle several source languages.
4990 It determines the type of each source file from its filename extension,
4991 and will switch expression parsing and number formatting to match the
4992 language of the function in the currently selected stack frame.
4993 You can also specifically set the language to be used, with
4994 `set language c' or `set language modula-2'.
4998 GDB now has preliminary support for the GNU Modula-2 compiler,
4999 currently under development at the State University of New York at
5000 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5001 continue through the fall of 1991 and into 1992.
5003 Other Modula-2 compilers are currently not supported, and attempting to
5004 debug programs compiled with them will likely result in an error as the
5005 symbol table is read. Feel free to work on it, though!
5007 There are hooks in GDB for strict type checking and range checking,
5008 in the `Modula-2 philosophy', but they do not currently work.
5012 GDB can now write to executable and core files (e.g. patch
5013 a variable's value). You must turn this switch on, specify
5014 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5015 by assigning a new value to a variable. Modifications take
5018 * Automatic SunOS shared library reading
5020 When you run your program, GDB automatically determines where its
5021 shared libraries (if any) have been loaded, and reads their symbols.
5022 The `share' command is no longer needed. This also works when
5023 examining core files.
5027 You can specify the number of lines that the `list' command shows.
5030 * New machines supported (host and target)
5032 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5033 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5034 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5036 * New hosts supported (not targets)
5038 IBM RT/PC: romp-ibm-aix or rtpc
5040 * New targets supported (not hosts)
5042 AMD 29000 embedded with COFF a29k-none-coff
5043 AMD 29000 embedded with a.out a29k-none-aout
5044 Ultracomputer remote kernel debug a29k-nyu-kern
5046 * New remote interfaces
5052 *** Changes in GDB-4.0:
5056 Wide output is wrapped at good places to make the output more readable.
5058 Gdb now supports cross-debugging from a host machine of one type to a
5059 target machine of another type. Communication with the target system
5060 is over serial lines. The ``target'' command handles connecting to the
5061 remote system; the ``load'' command will download a program into the
5062 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5063 also supports debugging of realtime processes running under VxWorks,
5064 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5065 stub on the target system.
5067 New CPUs supported include the AMD 29000 and Intel 960.
5069 GDB now reads object files and symbol tables via a ``binary file''
5070 library, which allows a single copy of GDB to debug programs of multiple
5071 object file types such as a.out and coff.
5073 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5074 refcard.dvi and refcard.ps are available to format it).
5077 * Control-Variable user interface simplified
5079 All variables that control the operation of the debugger can be set
5080 by the ``set'' command, and displayed by the ``show'' command.
5082 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5083 ``Show prompt'' produces the response:
5084 Gdb's prompt is new-gdb=>.
5086 What follows are the NEW set commands. The command ``help set'' will
5087 print a complete list of old and new set commands. ``help set FOO''
5088 will give a longer description of the variable FOO. ``show'' will show
5089 all of the variable descriptions and their current settings.
5091 confirm on/off: Enables warning questions for operations that are
5092 hard to recover from, e.g. rerunning the program while
5093 it is already running. Default is ON.
5095 editing on/off: Enables EMACS style command line editing
5096 of input. Previous lines can be recalled with
5097 control-P, the current line can be edited with control-B,
5098 you can search for commands with control-R, etc.
5101 history filename NAME: NAME is where the gdb command history
5102 will be stored. The default is .gdb_history,
5103 or the value of the environment variable
5106 history size N: The size, in commands, of the command history. The
5107 default is 256, or the value of the environment variable
5110 history save on/off: If this value is set to ON, the history file will
5111 be saved after exiting gdb. If set to OFF, the
5112 file will not be saved. The default is OFF.
5114 history expansion on/off: If this value is set to ON, then csh-like
5115 history expansion will be performed on
5116 command line input. The default is OFF.
5118 radix N: Sets the default radix for input and output. It can be set
5119 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5120 in the current radix, so "set radix 10" is always a no-op.
5122 height N: This integer value is the number of lines on a page. Default
5123 is 24, the current `stty rows'' setting, or the ``li#''
5124 setting from the termcap entry matching the environment
5127 width N: This integer value is the number of characters on a line.
5128 Default is 80, the current `stty cols'' setting, or the ``co#''
5129 setting from the termcap entry matching the environment
5132 Note: ``set screensize'' is obsolete. Use ``set height'' and
5133 ``set width'' instead.
5135 print address on/off: Print memory addresses in various command displays,
5136 such as stack traces and structure values. Gdb looks
5137 more ``symbolic'' if you turn this off; it looks more
5138 ``machine level'' with it on. Default is ON.
5140 print array on/off: Prettyprint arrays. New convenient format! Default
5143 print demangle on/off: Print C++ symbols in "source" form if on,
5146 print asm-demangle on/off: Same, for assembler level printouts
5149 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5152 * Support for Epoch Environment.
5154 The epoch environment is a version of Emacs v18 with windowing. One
5155 new command, ``inspect'', is identical to ``print'', except that if you
5156 are running in the epoch environment, the value is printed in its own
5160 * Support for Shared Libraries
5162 GDB can now debug programs and core files that use SunOS shared libraries.
5163 Symbols from a shared library cannot be referenced
5164 before the shared library has been linked with the program (this
5165 happens after you type ``run'' and before the function main() is entered).
5166 At any time after this linking (including when examining core files
5167 from dynamically linked programs), gdb reads the symbols from each
5168 shared library when you type the ``sharedlibrary'' command.
5169 It can be abbreviated ``share''.
5171 sharedlibrary REGEXP: Load shared object library symbols for files
5172 matching a unix regular expression. No argument
5173 indicates to load symbols for all shared libraries.
5175 info sharedlibrary: Status of loaded shared libraries.
5180 A watchpoint stops execution of a program whenever the value of an
5181 expression changes. Checking for this slows down execution
5182 tremendously whenever you are in the scope of the expression, but is
5183 quite useful for catching tough ``bit-spreader'' or pointer misuse
5184 problems. Some machines such as the 386 have hardware for doing this
5185 more quickly, and future versions of gdb will use this hardware.
5187 watch EXP: Set a watchpoint (breakpoint) for an expression.
5189 info watchpoints: Information about your watchpoints.
5191 delete N: Deletes watchpoint number N (same as breakpoints).
5192 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5193 enable N: Re-enables watchpoint number N (same as breakpoints).
5196 * C++ multiple inheritance
5198 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5201 * C++ exception handling
5203 Gdb now supports limited C++ exception handling. Besides the existing
5204 ability to breakpoint on an exception handler, gdb can breakpoint on
5205 the raising of an exception (before the stack is peeled back to the
5208 catch FOO: If there is a FOO exception handler in the dynamic scope,
5209 set a breakpoint to catch exceptions which may be raised there.
5210 Multiple exceptions (``catch foo bar baz'') may be caught.
5212 info catch: Lists all exceptions which may be caught in the
5213 current stack frame.
5216 * Minor command changes
5218 The command ``call func (arg, arg, ...)'' now acts like the print
5219 command, except it does not print or save a value if the function's result
5220 is void. This is similar to dbx usage.
5222 The ``up'' and ``down'' commands now always print the frame they end up
5223 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5224 frames without printing.
5226 * New directory command
5228 'dir' now adds directories to the FRONT of the source search path.
5229 The path starts off empty. Source files that contain debug information
5230 about the directory in which they were compiled can be found even
5231 with an empty path; Sun CC and GCC include this information. If GDB can't
5232 find your source file in the current directory, type "dir .".
5234 * Configuring GDB for compilation
5236 For normal use, type ``./configure host''. See README or gdb.texinfo
5239 GDB now handles cross debugging. If you are remotely debugging between
5240 two different machines, type ``./configure host -target=targ''.
5241 Host is the machine where GDB will run; targ is the machine
5242 where the program that you are debugging will run.