1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.5
8 ** Vectors can be created with gdb.Type.vector.
10 * New Python-based convenience functions:
12 ** $_memeq(buf1, buf2, length)
13 ** $_streq(str1, str2)
15 ** $_regex(str, regex)
17 * The 'cd' command now defaults to using '~' (the home directory) if not
20 * New configure options
22 --enable-libmcheck/--disable-libmcheck
23 By default, development versions are built with -lmcheck on hosts
24 that support it, in order to help track memory corruption issues.
25 Release versions, on the other hand, are built without -lmcheck
26 by default. The --enable-libmcheck/--disable-libmcheck configure
27 options allow the user to override that default.
29 * New commands (for set/show, see "New options" below)
32 List the BFDs known to GDB.
34 python-interactive [command]
36 Start a Python interactive prompt, or evaluate the optional command
37 and print the result of expressions.
40 "py" is a new alias for "python".
44 ** Command parameter changes are now notified using new async record
47 *** Changes in GDB 7.5
49 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
50 for more x32 ABI info.
52 * GDB now supports access to MIPS DSP registers on Linux targets.
54 * GDB now supports debugging microMIPS binaries.
56 * The "info os" command on GNU/Linux can now display information on
57 several new classes of objects managed by the operating system:
58 "info os procgroups" lists process groups
59 "info os files" lists file descriptors
60 "info os sockets" lists internet-domain sockets
61 "info os shm" lists shared-memory regions
62 "info os semaphores" lists semaphores
63 "info os msg" lists message queues
64 "info os modules" lists loaded kernel modules
66 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
67 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
68 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
69 options and inspect the probe arguments using the new $_probe_arg family
70 of convenience variables. You can obtain more information about SystemTap
71 in <http://sourceware.org/systemtap/>.
73 * GDB now supports reversible debugging on ARM, it allows you to
74 debug basic ARM and THUMB instructions, and provides
75 record/replay support.
77 * The option "symbol-reloading" has been deleted as it is no longer used.
81 ** GDB commands implemented in Python can now be put in command class
84 ** The "maint set python print-stack on|off" is now deleted.
86 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
87 apply "flag enum"-style pretty-printing to any enum.
89 ** gdb.lookup_symbol can now work when there is no current frame.
91 ** gdb.Symbol now has a 'line' attribute, holding the line number in
92 the source at which the symbol was defined.
94 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
95 method 'value'. The former indicates whether the symbol needs a
96 frame in order to compute its value, and the latter computes the
99 ** A new method 'referenced_value' on gdb.Value objects which can
100 dereference pointer as well as C++ reference values.
102 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
103 which return the global and static blocks (as gdb.Block objects),
104 of the underlying symbol table, respectively.
106 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
107 object associated with a PC value.
109 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
110 of the address range occupied by code for the current source line.
112 * Go language support.
113 GDB now supports debugging programs written in the Go programming
116 * GDBserver now supports stdio connections.
117 E.g. (gdb) target remote | ssh myhost gdbserver - hello
119 * The binary "gdbtui" can no longer be built or installed.
120 Use "gdb -tui" instead.
122 * GDB will now print "flag" enums specially. A flag enum is one where
123 all the enumerator values have no bits in common when pairwise
124 "and"ed. When printing a value whose type is a flag enum, GDB will
125 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
126 (gdb) print (enum E) 3
129 * The filename part of a linespec will now match trailing components
130 of a source file name. For example, "break gcc/expr.c:1000" will
131 now set a breakpoint in build/gcc/expr.c, but not
134 * The "info proc" and "generate-core-file" commands will now also
135 work on remote targets connected to GDBserver on Linux.
137 * The command "info catch" has been removed. It has been disabled
140 * The "catch exception" and "catch assert" commands now accept
141 a condition at the end of the command, much like the "break"
142 command does. For instance:
144 (gdb) catch exception Constraint_Error if Barrier = True
146 Previously, it was possible to add a condition to such catchpoints,
147 but it had to be done as a second step, after the catchpoint had been
148 created, using the "condition" command.
150 * The "info static-tracepoint-marker" command will now also work on
151 native Linux targets with in-process agent.
153 * GDB can now set breakpoints on inlined functions.
155 * The .gdb_index section has been updated to include symbols for
156 inlined functions. GDB will ignore older .gdb_index sections by
157 default, which could cause symbol files to be loaded more slowly
158 until their .gdb_index sections can be recreated. The new command
159 "set use-deprecated-index-sections on" will cause GDB to use any older
160 .gdb_index sections it finds. This will restore performance, but the
161 ability to set breakpoints on inlined functions will be lost in symbol
162 files with older .gdb_index sections.
164 The .gdb_index section has also been updated to record more information
165 about each symbol. This speeds up the "info variables", "info functions"
166 and "info types" commands when used with programs having the .gdb_index
167 section, as well as speeding up debugging with shared libraries using
168 the .gdb_index section.
170 * Ada support for GDB/MI Variable Objects has been added.
172 * GDB can now support 'breakpoint always-inserted mode' in 'record'
177 ** New command -info-os is the MI equivalent of "info os".
179 ** Output logs ("set logging" and related) now include MI output.
183 ** "set use-deprecated-index-sections on|off"
184 "show use-deprecated-index-sections on|off"
185 Controls the use of deprecated .gdb_index sections.
187 ** "catch load" and "catch unload" can be used to stop when a shared
188 library is loaded or unloaded, respectively.
190 ** "enable count" can be used to auto-disable a breakpoint after
193 ** "info vtbl" can be used to show the virtual method tables for
194 C++ and Java objects.
196 ** "explore" and its sub commands "explore value" and "explore type"
197 can be used to reccursively explore values and types of
198 expressions. These commands are available only if GDB is
199 configured with '--with-python'.
201 ** "info auto-load" shows status of all kinds of auto-loaded files,
202 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
203 sequences of commands files, "info auto-load python-scripts"
204 shows status of auto-loading Python script files,
205 "info auto-load local-gdbinit" shows status of loading init file
206 (.gdbinit) from current directory and "info auto-load libthread-db" shows
207 status of inferior specific thread debugging shared library loading.
209 ** "info auto-load-scripts", "set auto-load-scripts on|off"
210 and "show auto-load-scripts" commands have been deprecated, use their
211 "info auto-load python-scripts", "set auto-load python-scripts on|off"
212 and "show auto-load python-scripts" counterparts instead.
214 ** "dprintf location,format,args..." creates a dynamic printf, which
215 is basically a breakpoint that does a printf and immediately
216 resumes your program's execution, so it is like a printf that you
217 can insert dynamically at runtime instead of at compiletime.
219 ** "set print symbol"
221 Controls whether GDB attempts to display the symbol, if any,
222 corresponding to addresses it prints. This defaults to "on", but
223 you can set it to "off" to restore GDB's previous behavior.
225 * Deprecated commands
227 ** For the Renesas Super-H architecture, the "regs" command has been
228 deprecated, and "info all-registers" should be used instead.
232 Renesas RL78 rl78-*-elf
233 HP OpenVMS ia64 ia64-hp-openvms*
235 * GDBserver supports evaluation of breakpoint conditions. When
236 support is advertised by GDBserver, GDB may be told to send the
237 breakpoint conditions in bytecode form to GDBserver. GDBserver
238 will only report the breakpoint trigger to GDB when its condition
244 show mips compression
245 Select the compressed ISA encoding used in functions that have no symbol
246 information available. The encoding can be set to either of:
249 and is updated automatically from ELF file flags if available.
251 set breakpoint condition-evaluation
252 show breakpoint condition-evaluation
253 Control whether breakpoint conditions are evaluated by GDB ("host") or by
254 GDBserver ("target"). Default option "auto" chooses the most efficient
256 This option can improve debugger efficiency depending on the speed of the
260 Disable auto-loading globally.
263 Show auto-loading setting of all kinds of auto-loaded files.
265 set auto-load gdb-scripts on|off
266 show auto-load gdb-scripts
267 Control auto-loading of GDB canned sequences of commands files.
269 set auto-load python-scripts on|off
270 show auto-load python-scripts
271 Control auto-loading of Python script files.
273 set auto-load local-gdbinit on|off
274 show auto-load local-gdbinit
275 Control loading of init file (.gdbinit) from current directory.
277 set auto-load libthread-db on|off
278 show auto-load libthread-db
279 Control auto-loading of inferior specific thread debugging shared library.
281 set auto-load scripts-directory <dir1>[:<dir2>...]
282 show auto-load scripts-directory
283 Set a list of directories from which to load auto-loaded scripts.
284 Automatically loaded Python scripts and GDB scripts are located in one
285 of the directories listed by this option.
286 The delimiter (':' above) may differ according to the host platform.
288 set auto-load safe-path <dir1>[:<dir2>...]
289 show auto-load safe-path
290 Set a list of directories from which it is safe to auto-load files.
291 The delimiter (':' above) may differ according to the host platform.
293 set debug auto-load on|off
295 Control display of debugging info for auto-loading the files above.
297 set dprintf-style gdb|call|agent
299 Control the way in which a dynamic printf is performed; "gdb"
300 requests a GDB printf command, while "call" causes dprintf to call a
301 function in the inferior. "agent" requests that the target agent
302 (such as GDBserver) do the printing.
304 set dprintf-function <expr>
305 show dprintf-function
306 set dprintf-channel <expr>
308 Set the function and optional first argument to the call when using
309 the "call" style of dynamic printf.
311 set disconnected-dprintf on|off
312 show disconnected-dprintf
313 Control whether agent-style dynamic printfs continue to be in effect
314 after GDB disconnects.
316 * New configure options
319 Configure default value for the 'set auto-load scripts-directory'
320 setting above. It defaults to '$debugdir:$datadir/auto-load',
321 $debugdir representing global debugging info directories (available
322 via 'show debug-file-directory') and $datadir representing GDB's data
323 directory (available via 'show data-directory').
325 --with-auto-load-safe-path
326 Configure default value for the 'set auto-load safe-path' setting
327 above. It defaults to the --with-auto-load-dir setting.
329 --without-auto-load-safe-path
330 Set 'set auto-load safe-path' to '/', effectively disabling this
335 z0/z1 conditional breakpoints extension
337 The z0/z1 breakpoint insertion packets have been extended to carry
338 a list of conditional expressions over to the remote stub depending on the
339 condition evaluation mode. The use of this extension can be controlled
340 via the "set remote conditional-breakpoints-packet" command.
344 Specify the signals which the remote stub may pass to the debugged
345 program without GDB involvement.
347 * New command line options
349 --init-command=FILE, -ix Like --command, -x but execute it
350 before loading inferior.
351 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
352 execute it before loading inferior.
354 *** Changes in GDB 7.4
356 * GDB now handles ambiguous linespecs more consistently; the existing
357 FILE:LINE support has been expanded to other types of linespecs. A
358 breakpoint will now be set on all matching locations in all
359 inferiors, and locations will be added or removed according to
362 * GDB now allows you to skip uninteresting functions and files when
363 stepping with the "skip function" and "skip file" commands.
365 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
366 and "show remote hardware-watchpoint-length-limit". These allows to
367 set or show the maximum length limit (in bytes) of a remote
368 target hardware watchpoint.
370 This allows e.g. to use "unlimited" hardware watchpoints with the
371 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
372 watchpoints are slower than real hardware watchpoints but are
373 significantly faster than gdb software watchpoints.
377 ** The register_pretty_printer function in module gdb.printing now takes
378 an optional `replace' argument. If True, the new printer replaces any
381 ** The "maint set python print-stack on|off" command has been
382 deprecated and will be deleted in GDB 7.5.
383 A new command: "set python print-stack none|full|message" has
384 replaced it. Additionally, the default for "print-stack" is
385 now "message", which just prints the error message without
388 ** A prompt substitution hook (prompt_hook) is now available to the
391 ** A new Python module, gdb.prompt has been added to the GDB Python
392 modules library. This module provides functionality for
393 escape sequences in prompts (used by set/show
394 extended-prompt). These escape sequences are replaced by their
397 ** Python commands and convenience-functions located in
398 'data-directory'/python/gdb/command and
399 'data-directory'/python/gdb/function are now automatically loaded
402 ** Blocks now provide four new attributes. global_block and
403 static_block will return the global and static blocks
404 respectively. is_static and is_global are boolean attributes
405 that indicate if the block is one of those two types.
407 ** Symbols now provide the "type" attribute, the type of the symbol.
409 ** The "gdb.breakpoint" function has been deprecated in favor of
412 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
413 of a function. This class is based on the "finish" command
414 available in the CLI.
416 ** Type objects for struct and union types now allow access to
417 the fields using standard Python dictionary (mapping) methods.
418 For example, "some_type['myfield']" now works, as does
421 ** A new event "gdb.new_objfile" has been added, triggered by loading a
424 ** A new function, "deep_items" has been added to the gdb.types
425 module in the GDB Python modules library. This function returns
426 an iterator over the fields of a struct or union type. Unlike
427 the standard Python "iteritems" method, it will recursively traverse
428 any anonymous fields.
432 ** "*stopped" events can report several new "reason"s, such as
435 ** Breakpoint changes are now notified using new async records, like
436 "=breakpoint-modified".
438 ** New command -ada-task-info.
440 * libthread-db-search-path now supports two special values: $sdir and $pdir.
441 $sdir specifies the default system locations of shared libraries.
442 $pdir specifies the directory where the libpthread used by the application
445 GDB no longer looks in $sdir and $pdir after it has searched the directories
446 mentioned in libthread-db-search-path. If you want to search those
447 directories, they must be specified in libthread-db-search-path.
448 The default value of libthread-db-search-path on GNU/Linux and Solaris
449 systems is now "$sdir:$pdir".
451 $pdir is not supported by gdbserver, it is currently ignored.
452 $sdir is supported by gdbserver.
454 * New configure option --with-iconv-bin.
455 When using the internationalization support like the one in the GNU C
456 library, GDB will invoke the "iconv" program to get a list of supported
457 character sets. If this program lives in a non-standard location, one can
458 use this option to specify where to find it.
460 * When natively debugging programs on PowerPC BookE processors running
461 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
462 watchpoints, which specify a mask in addition to an address to watch.
463 The mask specifies that some bits of an address (the bits which are
464 reset in the mask) should be ignored when matching the address accessed
465 by the inferior against the watchpoint address. See the "PowerPC Embedded"
466 section in the user manual for more details.
468 * The new option --once causes GDBserver to stop listening for connections once
469 the first connection is made. The listening port used by GDBserver will
470 become available after that.
472 * New commands "info macros" and "alias" have been added.
474 * New function parameters suffix @entry specifies value of function parameter
475 at the time the function got called. Entry values are available only since
481 "!" is now an alias of the "shell" command.
482 Note that no space is needed between "!" and SHELL COMMAND.
486 watch EXPRESSION mask MASK_VALUE
487 The watch command now supports the mask argument which allows creation
488 of masked watchpoints, if the current architecture supports this feature.
490 info auto-load-scripts [REGEXP]
491 This command was formerly named "maintenance print section-scripts".
492 It is now generally useful and is no longer a maintenance-only command.
494 info macro [-all] [--] MACRO
495 The info macro command has new options `-all' and `--'. The first for
496 printing all definitions of a macro. The second for explicitly specifying
497 the end of arguments and the beginning of the macro name in case the macro
498 name starts with a hyphen.
500 collect[/s] EXPRESSIONS
501 The tracepoint collect command now takes an optional modifier "/s"
502 that directs it to dereference pointer-to-character types and
503 collect the bytes of memory up to a zero byte. The behavior is
504 similar to what you see when you use the regular print command on a
505 string. An optional integer following the "/s" sets a bound on the
506 number of bytes that will be collected.
509 The trace start command now interprets any supplied arguments as a
510 note to be recorded with the trace run, with an effect similar to
511 setting the variable trace-notes.
514 The trace stop command now interprets any arguments as a note to be
515 mentioned along with the tstatus report that the trace was stopped
516 with a command. The effect is similar to setting the variable
519 * Tracepoints can now be enabled and disabled at any time after a trace
520 experiment has been started using the standard "enable" and "disable"
521 commands. It is now possible to start a trace experiment with no enabled
522 tracepoints; GDB will display a warning, but will allow the experiment to
523 begin, assuming that tracepoints will be enabled as needed while the trace
526 * Fast tracepoints on 32-bit x86-architectures can now be placed at
527 locations with 4-byte instructions, when they were previously
528 limited to locations with instructions of 5 bytes or longer.
532 set debug dwarf2-read
533 show debug dwarf2-read
534 Turns on or off display of debugging messages related to reading
535 DWARF debug info. The default is off.
537 set debug symtab-create
538 show debug symtab-create
539 Turns on or off display of debugging messages related to symbol table
540 creation. The default is off.
544 Set the GDB prompt, and allow escape sequences to be inserted to
545 display miscellaneous information (see 'help set extended-prompt'
546 for the list of sequences). This prompt (and any information
547 accessed through the escape sequences) is updated every time the
550 set print entry-values (both|compact|default|if-needed|no|only|preferred)
551 show print entry-values
552 Set printing of frame argument values at function entry. In some cases
553 GDB can determine the value of function argument which was passed by the
554 function caller, even if the value was modified inside the called function.
556 set debug entry-values
557 show debug entry-values
558 Control display of debugging info for determining frame argument values at
559 function entry and virtual tail call frames.
561 set basenames-may-differ
562 show basenames-may-differ
563 Set whether a source file may have multiple base names.
564 (A "base name" is the name of a file with the directory part removed.
565 Example: The base name of "/home/user/hello.c" is "hello.c".)
566 If set, GDB will canonicalize file names (e.g., expand symlinks)
567 before comparing them. Canonicalization is an expensive operation,
568 but it allows the same file be known by more than one base name.
569 If not set (the default), all source files are assumed to have just
570 one base name, and gdb will do file name comparisons more efficiently.
576 Set a user name and notes for the current and any future trace runs.
577 This is useful for long-running and/or disconnected traces, to
578 inform others (or yourself) as to who is running the trace, supply
579 contact information, or otherwise explain what is going on.
582 show trace-stop-notes
583 Set a note attached to the trace run, that is displayed when the
584 trace has been stopped by a tstop command. This is useful for
585 instance as an explanation, if you are stopping a trace run that was
586 started by someone else.
592 Dynamically enable a tracepoint in a started trace experiment.
596 Dynamically disable a tracepoint in a started trace experiment.
600 Set the user and notes of the trace run.
604 Query the current status of a tracepoint.
608 Query the minimum length of instruction at which a fast tracepoint may
611 * Dcache size (number of lines) and line-size are now runtime-configurable
612 via "set dcache line" and "set dcache line-size" commands.
616 Texas Instruments TMS320C6x tic6x-*-*
620 Renesas RL78 rl78-*-elf
622 *** Changes in GDB 7.3.1
624 * The build failure for NetBSD and OpenBSD targets have now been fixed.
626 *** Changes in GDB 7.3
628 * GDB has a new command: "thread find [REGEXP]".
629 It finds the thread id whose name, target id, or thread extra info
630 matches the given regular expression.
632 * The "catch syscall" command now works on mips*-linux* targets.
634 * The -data-disassemble MI command now supports modes 2 and 3 for
635 dumping the instruction opcodes.
637 * New command line options
639 -data-directory DIR Specify DIR as the "data-directory".
640 This is mostly for testing purposes.
642 * The "maint set python auto-load on|off" command has been renamed to
643 "set auto-load-scripts on|off".
645 * GDB has a new command: "set directories".
646 It is like the "dir" command except that it replaces the
647 source path list instead of augmenting it.
649 * GDB now understands thread names.
651 On GNU/Linux, "info threads" will display the thread name as set by
652 prctl or pthread_setname_np.
654 There is also a new command, "thread name", which can be used to
655 assign a name internally for GDB to display.
658 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
659 has been integrated into GDB.
663 ** The function gdb.Write now accepts an optional keyword 'stream'.
664 This keyword, when provided, will direct the output to either
665 stdout, stderr, or GDB's logging output.
667 ** Parameters can now be be sub-classed in Python, and in particular
668 you may implement the get_set_doc and get_show_doc functions.
669 This improves how Parameter set/show documentation is processed
670 and allows for more dynamic content.
672 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
673 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
674 have an is_valid method.
676 ** Breakpoints can now be sub-classed in Python, and in particular
677 you may implement a 'stop' function that is executed each time
678 the inferior reaches that breakpoint.
680 ** New function gdb.lookup_global_symbol looks up a global symbol.
682 ** GDB values in Python are now callable if the value represents a
683 function. For example, if 'some_value' represents a function that
684 takes two integer parameters and returns a value, you can call
685 that function like so:
687 result = some_value (10,20)
689 ** Module gdb.types has been added.
690 It contains a collection of utilities for working with gdb.Types objects:
691 get_basic_type, has_field, make_enum_dict.
693 ** Module gdb.printing has been added.
694 It contains utilities for writing and registering pretty-printers.
695 New classes: PrettyPrinter, SubPrettyPrinter,
696 RegexpCollectionPrettyPrinter.
697 New function: register_pretty_printer.
699 ** New commands "info pretty-printers", "enable pretty-printer" and
700 "disable pretty-printer" have been added.
702 ** gdb.parameter("directories") is now available.
704 ** New function gdb.newest_frame returns the newest frame in the
707 ** The gdb.InferiorThread class has a new "name" attribute. This
708 holds the thread's name.
710 ** Python Support for Inferior events.
711 Python scripts can add observers to be notified of events
712 occurring in the process being debugged.
713 The following events are currently supported:
714 - gdb.events.cont Continue event.
715 - gdb.events.exited Inferior exited event.
716 - gdb.events.stop Signal received, and Breakpoint hit events.
720 ** GDB now puts template parameters in scope when debugging in an
721 instantiation. For example, if you have:
723 template<int X> int func (void) { return X; }
725 then if you step into func<5>, "print X" will show "5". This
726 feature requires proper debuginfo support from the compiler; it
727 was added to GCC 4.5.
729 ** The motion commands "next", "finish", "until", and "advance" now
730 work better when exceptions are thrown. In particular, GDB will
731 no longer lose control of the inferior; instead, the GDB will
732 stop the inferior at the point at which the exception is caught.
733 This functionality requires a change in the exception handling
734 code that was introduced in GCC 4.5.
736 * GDB now follows GCC's rules on accessing volatile objects when
737 reading or writing target state during expression evaluation.
738 One notable difference to prior behavior is that "print x = 0"
739 no longer generates a read of x; the value of the assignment is
740 now always taken directly from the value being assigned.
742 * GDB now has some support for using labels in the program's source in
743 linespecs. For instance, you can use "advance label" to continue
744 execution to a label.
746 * GDB now has support for reading and writing a new .gdb_index
747 section. This section holds a fast index of DWARF debugging
748 information and can be used to greatly speed up GDB startup and
749 operation. See the documentation for `save gdb-index' for details.
751 * The "watch" command now accepts an optional "-location" argument.
752 When used, this causes GDB to watch the memory referred to by the
753 expression. Such a watchpoint is never deleted due to it going out
756 * GDB now supports thread debugging of core dumps on GNU/Linux.
758 GDB now activates thread debugging using the libthread_db library
759 when debugging GNU/Linux core dumps, similarly to when debugging
760 live processes. As a result, when debugging a core dump file, GDB
761 is now able to display pthread_t ids of threads. For example, "info
762 threads" shows the same output as when debugging the process when it
763 was live. In earlier releases, you'd see something like this:
766 * 1 LWP 6780 main () at main.c:10
768 While now you see this:
771 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
773 It is also now possible to inspect TLS variables when debugging core
776 When debugging a core dump generated on a machine other than the one
777 used to run GDB, you may need to point GDB at the correct
778 libthread_db library with the "set libthread-db-search-path"
779 command. See the user manual for more details on this command.
781 * When natively debugging programs on PowerPC BookE processors running
782 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
783 which stop execution of the inferior whenever it executes an instruction
784 at any address within the specified range. See the "PowerPC Embedded"
785 section in the user manual for more details.
787 * New features in the GDB remote stub, GDBserver
789 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
790 and i686 LynxOS (version 5.x).
792 ** GDBserver is now supported on Blackfin Linux.
794 * New native configurations
796 ia64 HP-UX ia64-*-hpux*
800 Analog Devices, Inc. Blackfin Processor bfin-*
802 * Ada task switching is now supported on sparc-elf targets when
803 debugging a program using the Ravenscar Profile. For more information,
804 see the "Tasking Support when using the Ravenscar Profile" section
805 in the GDB user manual.
807 * Guile support was removed.
809 * New features in the GNU simulator
811 ** The --map-info flag lists all known core mappings.
813 ** CFI flashes may be simulated via the "cfi" device.
815 *** Changes in GDB 7.2
817 * Shared library support for remote targets by default
819 When GDB is configured for a generic, non-OS specific target, like
820 for example, --target=arm-eabi or one of the many *-*-elf targets,
821 GDB now queries remote stubs for loaded shared libraries using the
822 `qXfer:libraries:read' packet. Previously, shared library support
823 was always disabled for such configurations.
827 ** Argument Dependent Lookup (ADL)
829 In C++ ADL lookup directs function search to the namespaces of its
830 arguments even if the namespace has not been imported.
840 Here the compiler will search for `foo' in the namespace of 'b'
841 and find A::foo. GDB now supports this. This construct is commonly
842 used in the Standard Template Library for operators.
844 ** Improved User Defined Operator Support
846 In addition to member operators, GDB now supports lookup of operators
847 defined in a namespace and imported with a `using' directive, operators
848 defined in the global scope, operators imported implicitly from an
849 anonymous namespace, and the ADL operators mentioned in the previous
851 GDB now also supports proper overload resolution for all the previously
852 mentioned flavors of operators.
854 ** static const class members
856 Printing of static const class members that are initialized in the
857 class definition has been fixed.
859 * Windows Thread Information Block access.
861 On Windows targets, GDB now supports displaying the Windows Thread
862 Information Block (TIB) structure. This structure is visible either
863 by using the new command `info w32 thread-information-block' or, by
864 dereferencing the new convenience variable named `$_tlb', a
865 thread-specific pointer to the TIB. This feature is also supported
866 when remote debugging using GDBserver.
870 Static tracepoints are calls in the user program into a tracing
871 library. One such library is a port of the LTTng kernel tracer to
872 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
873 When debugging with GDBserver, GDB now supports combining the GDB
874 tracepoint machinery with such libraries. For example: the user can
875 use GDB to probe a static tracepoint marker (a call from the user
876 program into the tracing library) with the new "strace" command (see
877 "New commands" below). This creates a "static tracepoint" in the
878 breakpoint list, that can be manipulated with the same feature set
879 as fast and regular tracepoints. E.g., collect registers, local and
880 global variables, collect trace state variables, and define
881 tracepoint conditions. In addition, the user can collect extra
882 static tracepoint marker specific data, by collecting the new
883 $_sdata internal variable. When analyzing the trace buffer, you can
884 inspect $_sdata like any other variable available to GDB. For more
885 information, see the "Tracepoints" chapter in GDB user manual. New
886 remote packets have been defined to support static tracepoints, see
887 the "New remote packets" section below.
889 * Better reconstruction of tracepoints after disconnected tracing
891 GDB will attempt to download the original source form of tracepoint
892 definitions when starting a trace run, and then will upload these
893 upon reconnection to the target, resulting in a more accurate
894 reconstruction of the tracepoints that are in use on the target.
898 You can now exercise direct control over the ways that GDB can
899 affect your program. For instance, you can disallow the setting of
900 breakpoints, so that the program can run continuously (assuming
901 non-stop mode). In addition, the "observer" variable is available
902 to switch all of the different controls; in observer mode, GDB
903 cannot affect the target's behavior at all, which is useful for
904 tasks like diagnosing live systems in the field.
906 * The new convenience variable $_thread holds the number of the
913 Return the address of the Windows Thread Information Block of a given thread.
917 In response to several of the tracepoint packets, the target may now
918 also respond with a number of intermediate `qRelocInsn' request
919 packets before the final result packet, to have GDB handle
920 relocating an instruction to execute at a different address. This
921 is particularly useful for stubs that support fast tracepoints. GDB
922 reports support for this feature in the qSupported packet.
926 List static tracepoint markers in the target program.
930 List static tracepoint markers at a given address in the target
933 qXfer:statictrace:read
935 Read the static trace data collected (by a `collect $_sdata'
936 tracepoint action). The remote stub reports support for this packet
937 to gdb's qSupported query.
941 Send the current settings of GDB's permission flags.
945 Send part of the source (textual) form of a tracepoint definition,
946 which includes location, conditional, and action list.
948 * The source command now accepts a -s option to force searching for the
949 script in the source search path even if the script name specifies
952 * New features in the GDB remote stub, GDBserver
954 - GDBserver now support tracepoints (including fast tracepoints, and
955 static tracepoints). The feature is currently supported by the
956 i386-linux and amd64-linux builds. See the "Tracepoints support
957 in gdbserver" section in the manual for more information.
959 GDBserver JIT compiles the tracepoint's conditional agent
960 expression bytecode into native code whenever possible for low
961 overhead dynamic tracepoints conditionals. For such tracepoints,
962 an expression that examines program state is evaluated when the
963 tracepoint is reached, in order to determine whether to capture
964 trace data. If the condition is simple and false, processing the
965 tracepoint finishes very quickly and no data is gathered.
967 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
968 for static tracepoints support.
970 - GDBserver now supports x86_64 Windows 64-bit debugging.
972 * GDB now sends xmlRegisters= in qSupported packet to indicate that
973 it understands register description.
975 * The --batch flag now disables pagination and queries.
977 * X86 general purpose registers
979 GDB now supports reading/writing byte, word and double-word x86
980 general purpose registers directly. This means you can use, say,
981 $ah or $ax to refer, respectively, to the byte register AH and
982 16-bit word register AX that are actually portions of the 32-bit
983 register EAX or 64-bit register RAX.
985 * The `commands' command now accepts a range of breakpoints to modify.
986 A plain `commands' following a command that creates multiple
987 breakpoints affects all the breakpoints set by that command. This
988 applies to breakpoints set by `rbreak', and also applies when a
989 single `break' command creates multiple breakpoints (e.g.,
990 breakpoints on overloaded c++ functions).
992 * The `rbreak' command now accepts a filename specification as part of
993 its argument, limiting the functions selected by the regex to those
994 in the specified file.
996 * Support for remote debugging Windows and SymbianOS shared libraries
997 from Unix hosts has been improved. Non Windows GDB builds now can
998 understand target reported file names that follow MS-DOS based file
999 system semantics, such as file names that include drive letters and
1000 use the backslash character as directory separator. This makes it
1001 possible to transparently use the "set sysroot" and "set
1002 solib-search-path" on Unix hosts to point as host copies of the
1003 target's shared libraries. See the new command "set
1004 target-file-system-kind" described below, and the "Commands to
1005 specify files" section in the user manual for more information.
1009 eval template, expressions...
1010 Convert the values of one or more expressions under the control
1011 of the string template to a command line, and call it.
1013 set target-file-system-kind unix|dos-based|auto
1014 show target-file-system-kind
1015 Set or show the assumed file system kind for target reported file
1018 save breakpoints <filename>
1019 Save all current breakpoint definitions to a file suitable for use
1020 in a later debugging session. To read the saved breakpoint
1021 definitions, use the `source' command.
1023 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1026 info static-tracepoint-markers
1027 Display information about static tracepoint markers in the target.
1029 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1030 Define a static tracepoint by probing a marker at the given
1031 function, line, address, or marker ID.
1035 Enable and disable observer mode.
1037 set may-write-registers on|off
1038 set may-write-memory on|off
1039 set may-insert-breakpoints on|off
1040 set may-insert-tracepoints on|off
1041 set may-insert-fast-tracepoints on|off
1042 set may-interrupt on|off
1043 Set individual permissions for GDB effects on the target. Note that
1044 some of these settings can have undesirable or surprising
1045 consequences, particularly when changed in the middle of a session.
1046 For instance, disabling the writing of memory can prevent
1047 breakpoints from being inserted, cause single-stepping to fail, or
1048 even crash your program, if you disable after breakpoints have been
1049 inserted. However, GDB should not crash.
1051 set record memory-query on|off
1052 show record memory-query
1053 Control whether to stop the inferior if memory changes caused
1054 by an instruction cannot be recorded.
1059 The disassemble command now supports "start,+length" form of two arguments.
1063 ** GDB now provides a new directory location, called the python directory,
1064 where Python scripts written for GDB can be installed. The location
1065 of that directory is <data-directory>/python, where <data-directory>
1066 is the GDB data directory. For more details, see section `Scripting
1067 GDB using Python' in the manual.
1069 ** The GDB Python API now has access to breakpoints, symbols, symbol
1070 tables, program spaces, inferiors, threads and frame's code blocks.
1071 Additionally, GDB Parameters can now be created from the API, and
1072 manipulated via set/show in the CLI.
1074 ** New functions gdb.target_charset, gdb.target_wide_charset,
1075 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1077 ** New exception gdb.GdbError.
1079 ** Pretty-printers are now also looked up in the current program space.
1081 ** Pretty-printers can now be individually enabled and disabled.
1083 ** GDB now looks for names of Python scripts to auto-load in a
1084 special section named `.debug_gdb_scripts', in addition to looking
1085 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1087 * Tracepoint actions were unified with breakpoint commands. In particular,
1088 there are no longer differences in "info break" output for breakpoints and
1089 tracepoints and the "commands" command can be used for both tracepoints and
1090 regular breakpoints.
1094 ARM Symbian arm*-*-symbianelf*
1096 * D language support.
1097 GDB now supports debugging programs written in the D programming
1100 * GDB now supports the extended ptrace interface for PowerPC which is
1101 available since Linux kernel version 2.6.34. This automatically enables
1102 any hardware breakpoints and additional hardware watchpoints available in
1103 the processor. The old ptrace interface exposes just one hardware
1104 watchpoint and no hardware breakpoints.
1106 * GDB is now able to use the Data Value Compare (DVC) register available on
1107 embedded PowerPC processors to implement in hardware simple watchpoint
1108 conditions of the form:
1110 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1112 This works in native GDB running on Linux kernels with the extended ptrace
1113 interface mentioned above.
1115 *** Changes in GDB 7.1
1119 ** Namespace Support
1121 GDB now supports importing of namespaces in C++. This enables the
1122 user to inspect variables from imported namespaces. Support for
1123 namepace aliasing has also been added. So, if a namespace is
1124 aliased in the current scope (e.g. namepace C=A; ) the user can
1125 print variables using the alias (e.g. (gdb) print C::x).
1129 All known bugs relating to the printing of virtual base class were
1130 fixed. It is now possible to call overloaded static methods using a
1135 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1136 and reinterpret_cast<> are now handled by the C++ expression parser.
1140 Xilinx MicroBlaze microblaze-*-*
1145 Xilinx MicroBlaze microblaze
1148 * Multi-program debugging.
1150 GDB now has support for multi-program (a.k.a. multi-executable or
1151 multi-exec) debugging. This allows for debugging multiple inferiors
1152 simultaneously each running a different program under the same GDB
1153 session. See "Debugging Multiple Inferiors and Programs" in the
1154 manual for more information. This implied some user visible changes
1155 in the multi-inferior support. For example, "info inferiors" now
1156 lists inferiors that are not running yet or that have exited
1157 already. See also "New commands" and "New options" below.
1159 * New tracing features
1161 GDB's tracepoint facility now includes several new features:
1163 ** Trace state variables
1165 GDB tracepoints now include support for trace state variables, which
1166 are variables managed by the target agent during a tracing
1167 experiment. They are useful for tracepoints that trigger each
1168 other, so for instance one tracepoint can count hits in a variable,
1169 and then a second tracepoint has a condition that is true when the
1170 count reaches a particular value. Trace state variables share the
1171 $-syntax of GDB convenience variables, and can appear in both
1172 tracepoint actions and condition expressions. Use the "tvariable"
1173 command to create, and "info tvariables" to view; see "Trace State
1174 Variables" in the manual for more detail.
1178 GDB now includes an option for defining fast tracepoints, which
1179 targets may implement more efficiently, such as by installing a jump
1180 into the target agent rather than a trap instruction. The resulting
1181 speedup can be by two orders of magnitude or more, although the
1182 tradeoff is that some program locations on some target architectures
1183 might not allow fast tracepoint installation, for instance if the
1184 instruction to be replaced is shorter than the jump. To request a
1185 fast tracepoint, use the "ftrace" command, with syntax identical to
1186 the regular trace command.
1188 ** Disconnected tracing
1190 It is now possible to detach GDB from the target while it is running
1191 a trace experiment, then reconnect later to see how the experiment
1192 is going. In addition, a new variable disconnected-tracing lets you
1193 tell the target agent whether to continue running a trace if the
1194 connection is lost unexpectedly.
1198 GDB now has the ability to save the trace buffer into a file, and
1199 then use that file as a target, similarly to you can do with
1200 corefiles. You can select trace frames, print data that was
1201 collected in them, and use tstatus to display the state of the
1202 tracing run at the moment that it was saved. To create a trace
1203 file, use "tsave <filename>", and to use it, do "target tfile
1206 ** Circular trace buffer
1208 You can ask the target agent to handle the trace buffer as a
1209 circular buffer, discarding the oldest trace frames to make room for
1210 newer ones, by setting circular-trace-buffer to on. This feature may
1211 not be available for all target agents.
1216 The disassemble command, when invoked with two arguments, now requires
1217 the arguments to be comma-separated.
1220 The info variables command now displays variable definitions. Files
1221 which only declare a variable are not shown.
1224 The source command is now capable of sourcing Python scripts.
1225 This feature is dependent on the debugger being build with Python
1228 Related to this enhancement is also the introduction of a new command
1229 "set script-extension" (see below).
1231 * New commands (for set/show, see "New options" below)
1233 record save [<FILENAME>]
1234 Save a file (in core file format) containing the process record
1235 execution log for replay debugging at a later time.
1237 record restore <FILENAME>
1238 Restore the process record execution log that was saved at an
1239 earlier time, for replay debugging.
1241 add-inferior [-copies <N>] [-exec <FILENAME>]
1244 clone-inferior [-copies <N>] [ID]
1245 Make a new inferior ready to execute the same program another
1246 inferior has loaded.
1251 maint info program-spaces
1252 List the program spaces loaded into GDB.
1254 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1255 show remote interrupt-sequence
1256 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1257 as the sequence to the remote target in order to interrupt the execution.
1258 Ctrl-C is a default. Some system prefers BREAK which is high level of
1259 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1260 Magic SysRq g. It is BREAK signal and character 'g'.
1262 set remote interrupt-on-connect [on | off]
1263 show remote interrupt-on-connect
1264 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1265 remote target when gdb connects to it. This is needed when you debug
1268 set remotebreak [on | off]
1270 Deprecated. Use "set/show remote interrupt-sequence" instead.
1272 tvariable $NAME [ = EXP ]
1273 Create or modify a trace state variable.
1276 List trace state variables and their values.
1278 delete tvariable $NAME ...
1279 Delete one or more trace state variables.
1282 Evaluate the given expressions without collecting anything into the
1283 trace buffer. (Valid in tracepoint actions only.)
1285 ftrace FN / FILE:LINE / *ADDR
1286 Define a fast tracepoint at the given function, line, or address.
1288 * New expression syntax
1290 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1291 GDB now parses 0b101010 identically with 42.
1295 set follow-exec-mode new|same
1296 show follow-exec-mode
1297 Control whether GDB reuses the same inferior across an exec call or
1298 creates a new one. This is useful to be able to restart the old
1299 executable after the inferior having done an exec call.
1301 set default-collect EXPR, ...
1302 show default-collect
1303 Define a list of expressions to be collected at each tracepoint.
1304 This is a useful way to ensure essential items are not overlooked,
1305 such as registers or a critical global variable.
1307 set disconnected-tracing
1308 show disconnected-tracing
1309 If set to 1, the target is instructed to continue tracing if it
1310 loses its connection to GDB. If 0, the target is to stop tracing
1313 set circular-trace-buffer
1314 show circular-trace-buffer
1315 If set to on, the target is instructed to use a circular trace buffer
1316 and discard the oldest trace frames instead of stopping the trace due
1317 to a full trace buffer. If set to off, the trace stops when the buffer
1318 fills up. Some targets may not support this.
1320 set script-extension off|soft|strict
1321 show script-extension
1322 If set to "off", the debugger does not perform any script language
1323 recognition, and all sourced files are assumed to be GDB scripts.
1324 If set to "soft" (the default), files are sourced according to
1325 filename extension, falling back to GDB scripts if the first
1327 If set to "strict", files are sourced according to filename extension.
1329 set ada trust-PAD-over-XVS on|off
1330 show ada trust-PAD-over-XVS
1331 If off, activate a workaround against a bug in the debugging information
1332 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1333 the GCC sources for more information about the GNAT encoding and
1334 PAD types in particular). It is always safe to set this option to
1335 off, but this introduces a slight performance penalty. The default
1338 * Python API Improvements
1340 ** GDB provides the new class gdb.LazyString. This is useful in
1341 some pretty-printing cases. The new method gdb.Value.lazy_string
1342 provides a simple way to create objects of this type.
1344 ** The fields returned by gdb.Type.fields now have an
1345 `is_base_class' attribute.
1347 ** The new method gdb.Type.range returns the range of an array type.
1349 ** The new method gdb.parse_and_eval can be used to parse and
1350 evaluate an expression.
1352 * New remote packets
1355 Define a trace state variable.
1358 Get the current value of a trace state variable.
1361 Set desired tracing behavior upon disconnection.
1364 Set the trace buffer to be linear or circular.
1367 Get data about the tracepoints currently in use.
1371 Process record now works correctly with hardware watchpoints.
1373 Multiple bug fixes have been made to the mips-irix port, making it
1374 much more reliable. In particular:
1375 - Debugging threaded applications is now possible again. Previously,
1376 GDB would hang while starting the program, or while waiting for
1377 the program to stop at a breakpoint.
1378 - Attaching to a running process no longer hangs.
1379 - An error occurring while loading a core file has been fixed.
1380 - Changing the value of the PC register now works again. This fixes
1381 problems observed when using the "jump" command, or when calling
1382 a function from GDB, or even when assigning a new value to $pc.
1383 - With the "finish" and "return" commands, the return value for functions
1384 returning a small array is now correctly printed.
1385 - It is now possible to break on shared library code which gets executed
1386 during a shared library init phase (code executed while executing
1387 their .init section). Previously, the breakpoint would have no effect.
1388 - GDB is now able to backtrace through the signal handler for
1389 non-threaded programs.
1391 PIE (Position Independent Executable) programs debugging is now supported.
1392 This includes debugging execution of PIC (Position Independent Code) shared
1393 libraries although for that, it should be possible to run such libraries as an
1396 *** Changes in GDB 7.0
1398 * GDB now has an interface for JIT compilation. Applications that
1399 dynamically generate code can create symbol files in memory and register
1400 them with GDB. For users, the feature should work transparently, and
1401 for JIT developers, the interface is documented in the GDB manual in the
1402 "JIT Compilation Interface" chapter.
1404 * Tracepoints may now be conditional. The syntax is as for
1405 breakpoints; either an "if" clause appended to the "trace" command,
1406 or the "condition" command is available. GDB sends the condition to
1407 the target for evaluation using the same bytecode format as is used
1408 for tracepoint actions.
1410 * The disassemble command now supports: an optional /r modifier, print the
1411 raw instructions in hex as well as in symbolic form, and an optional /m
1412 modifier to print mixed source+assembly.
1414 * Process record and replay
1416 In a architecture environment that supports ``process record and
1417 replay'', ``process record and replay'' target can record a log of
1418 the process execution, and replay it with both forward and reverse
1421 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1422 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1423 set execution-direction {forward|reverse}, for targets that support
1426 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1427 feature is available with a native GDB running on kernel version
1430 * GDB now has support for multi-byte and wide character sets on the
1431 target. Strings whose character type is wchar_t, char16_t, or
1432 char32_t are now correctly printed. GDB supports wide- and unicode-
1433 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1434 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1435 `printf'. This feature requires iconv to work properly; if your
1436 system does not have a working iconv, GDB can use GNU libiconv. See
1437 the installation instructions for more information.
1439 * GDB now supports automatic retrieval of shared library files from
1440 remote targets. To use this feature, specify a system root that begins
1441 with the `remote:' prefix, either via the `set sysroot' command or via
1442 the `--with-sysroot' configure-time option.
1444 * "info sharedlibrary" now takes an optional regex of libraries to show,
1445 and it now reports if a shared library has no debugging information.
1447 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1448 now complete on file names.
1450 * When completing in expressions, gdb will attempt to limit
1451 completions to allowable structure or union fields, where appropriate.
1452 For instance, consider:
1454 # struct example { int f1; double f2; };
1455 # struct example variable;
1458 If the user types TAB at the end of this command line, the available
1459 completions will be "f1" and "f2".
1461 * Inlined functions are now supported. They show up in backtraces, and
1462 the "step", "next", and "finish" commands handle them automatically.
1464 * GDB now supports the token-splicing (##) and stringification (#)
1465 operators when expanding macros. It also supports variable-arity
1468 * GDB now supports inspecting extra signal information, exported by
1469 the new $_siginfo convenience variable. The feature is currently
1470 implemented on linux ARM, i386 and amd64.
1472 * GDB can now display the VFP floating point registers and NEON vector
1473 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1474 can provide these registers (requires Linux 2.6.30 or later). Remote
1475 and simulator targets may also provide them.
1477 * New remote packets
1480 Search memory for a sequence of bytes.
1483 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1484 operation over reliable transport links. Use of this packet is
1485 controlled by the `set remote noack-packet' command.
1488 Kill the process with the specified process ID. Use this in preference
1489 to `k' when multiprocess protocol extensions are supported.
1492 Obtains additional operating system information
1496 Read or write additional signal information.
1498 * Removed remote protocol undocumented extension
1500 An undocumented extension to the remote protocol's `S' stop reply
1501 packet that permited the stub to pass a process id was removed.
1502 Remote servers should use the `T' stop reply packet instead.
1504 * GDB now supports multiple function calling conventions according to the
1505 DWARF-2 DW_AT_calling_convention function attribute.
1507 * The SH target utilizes the aforementioned change to distinguish between gcc
1508 and Renesas calling convention. It also adds the new CLI commands
1509 `set/show sh calling-convention'.
1511 * GDB can now read compressed debug sections, as produced by GNU gold
1512 with the --compress-debug-sections=zlib flag.
1514 * 64-bit core files are now supported on AIX.
1516 * Thread switching is now supported on Tru64.
1518 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1519 which will be allocated using malloc later in program execution.
1521 * The qXfer:libraries:read remote procotol packet now allows passing a
1522 list of section offsets.
1524 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1525 conditions handling signals delivered during attach or thread creation
1526 have also been fixed.
1528 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1529 From the user's standpoint, all unqualified instances of True and False
1530 are treated as the standard definitions, regardless of context.
1532 * GDB now parses C++ symbol and type names more flexibly. For
1535 template<typename T> class C { };
1538 GDB will now correctly handle all of:
1540 ptype C<char const *>
1541 ptype C<char const*>
1542 ptype C<const char *>
1543 ptype C<const char*>
1545 * New features in the GDB remote stub, gdbserver
1547 - The "--wrapper" command-line argument tells gdbserver to use a
1548 wrapper program to launch programs for debugging.
1550 - On PowerPC and S/390 targets, it is now possible to use a single
1551 gdbserver executable to debug both 32-bit and 64-bit programs.
1552 (This requires gdbserver itself to be built as a 64-bit executable.)
1554 - gdbserver uses the new noack protocol mode for TCP connections to
1555 reduce communications latency, if also supported and enabled in GDB.
1557 - Support for the sparc64-linux-gnu target is now included in
1560 - The amd64-linux build of gdbserver now supports debugging both
1561 32-bit and 64-bit programs.
1563 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1564 now support hardware watchpoints, and will use them automatically
1569 GDB now has support for scripting using Python. Whether this is
1570 available is determined at configure time.
1572 New GDB commands can now be written in Python.
1574 * Ada tasking support
1576 Ada tasks can now be inspected in GDB. The following commands have
1580 Print the list of Ada tasks.
1582 Print detailed information about task number N.
1584 Print the task number of the current task.
1586 Switch the context of debugging to task number N.
1588 * Support for user-defined prefixed commands. The "define" command can
1589 add new commands to existing prefixes, e.g. "target".
1591 * Multi-inferior, multi-process debugging.
1593 GDB now has generalized support for multi-inferior debugging. See
1594 "Debugging Multiple Inferiors" in the manual for more information.
1595 Although availability still depends on target support, the command
1596 set is more uniform now. The GNU/Linux specific multi-forks support
1597 has been migrated to this new framework. This implied some user
1598 visible changes; see "New commands" and also "Removed commands"
1601 * Target descriptions can now describe the target OS ABI. See the
1602 "Target Description Format" section in the user manual for more
1605 * Target descriptions can now describe "compatible" architectures
1606 to indicate that the target can execute applications for a different
1607 architecture in addition to those for the main target architecture.
1608 See the "Target Description Format" section in the user manual for
1611 * Multi-architecture debugging.
1613 GDB now includes general supports for debugging applications on
1614 hybrid systems that use more than one single processor architecture
1615 at the same time. Each such hybrid architecture still requires
1616 specific support to be added. The only hybrid architecture supported
1617 in this version of GDB is the Cell Broadband Engine.
1619 * GDB now supports integrated debugging of Cell/B.E. applications that
1620 use both the PPU and SPU architectures. To enable support for hybrid
1621 Cell/B.E. debugging, you need to configure GDB to support both the
1622 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1623 --enable-targets configure option.
1625 * Non-stop mode debugging.
1627 For some targets, GDB now supports an optional mode of operation in
1628 which you can examine stopped threads while other threads continue
1629 to execute freely. This is referred to as non-stop mode, with the
1630 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1631 section in the user manual for more information.
1633 To be able to support remote non-stop debugging, a remote stub needs
1634 to implement the non-stop mode remote protocol extensions, as
1635 described in the "Remote Non-Stop" section of the user manual. The
1636 GDB remote stub, gdbserver, has been adjusted to support these
1637 extensions on linux targets.
1639 * New commands (for set/show, see "New options" below)
1641 catch syscall [NAME(S) | NUMBER(S)]
1642 Catch system calls. Arguments, which should be names of system
1643 calls or their numbers, mean catch only those syscalls. Without
1644 arguments, every syscall will be caught. When the inferior issues
1645 any of the specified syscalls, GDB will stop and announce the system
1646 call, both when it is called and when its call returns. This
1647 feature is currently available with a native GDB running on the
1648 Linux Kernel, under the following architectures: x86, x86_64,
1649 PowerPC and PowerPC64.
1651 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1653 Search memory for a sequence of bytes.
1655 maint set python print-stack
1656 maint show python print-stack
1657 Show a stack trace when an error is encountered in a Python script.
1660 Invoke CODE by passing it to the Python interpreter.
1665 These allow macros to be defined, undefined, and listed
1669 Show operating system information about processes.
1672 List the inferiors currently under GDB's control.
1675 Switch focus to inferior number NUM.
1678 Detach from inferior number NUM.
1681 Kill inferior number NUM.
1685 set spu stop-on-load
1686 show spu stop-on-load
1687 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1689 set spu auto-flush-cache
1690 show spu auto-flush-cache
1691 Control whether to automatically flush the software-managed cache
1692 during Cell/B.E. debugging.
1694 set sh calling-convention
1695 show sh calling-convention
1696 Control the calling convention used when calling SH target functions.
1699 show debug timestamp
1700 Control display of timestamps with GDB debugging output.
1702 set disassemble-next-line
1703 show disassemble-next-line
1704 Control display of disassembled source lines or instructions when
1707 set remote noack-packet
1708 show remote noack-packet
1709 Set/show the use of remote protocol QStartNoAckMode packet. See above
1710 under "New remote packets."
1712 set remote query-attached-packet
1713 show remote query-attached-packet
1714 Control use of remote protocol `qAttached' (query-attached) packet.
1716 set remote read-siginfo-object
1717 show remote read-siginfo-object
1718 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1721 set remote write-siginfo-object
1722 show remote write-siginfo-object
1723 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1726 set remote reverse-continue
1727 show remote reverse-continue
1728 Control use of remote protocol 'bc' (reverse-continue) packet.
1730 set remote reverse-step
1731 show remote reverse-step
1732 Control use of remote protocol 'bs' (reverse-step) packet.
1734 set displaced-stepping
1735 show displaced-stepping
1736 Control displaced stepping mode. Displaced stepping is a way to
1737 single-step over breakpoints without removing them from the debuggee.
1738 Also known as "out-of-line single-stepping".
1741 show debug displaced
1742 Control display of debugging info for displaced stepping.
1744 maint set internal-error
1745 maint show internal-error
1746 Control what GDB does when an internal error is detected.
1748 maint set internal-warning
1749 maint show internal-warning
1750 Control what GDB does when an internal warning is detected.
1755 Use a wrapper program to launch programs for debugging.
1757 set multiple-symbols (all|ask|cancel)
1758 show multiple-symbols
1759 The value of this variable can be changed to adjust the debugger behavior
1760 when an expression or a breakpoint location contains an ambiguous symbol
1761 name (an overloaded function name, for instance).
1763 set breakpoint always-inserted
1764 show breakpoint always-inserted
1765 Keep breakpoints always inserted in the target, as opposed to inserting
1766 them when resuming the target, and removing them when the target stops.
1767 This option can improve debugger performance on slow remote targets.
1769 set arm fallback-mode (arm|thumb|auto)
1770 show arm fallback-mode
1771 set arm force-mode (arm|thumb|auto)
1773 These commands control how ARM GDB determines whether instructions
1774 are ARM or Thumb. The default for both settings is auto, which uses
1775 the current CPSR value for instructions without symbols; previous
1776 versions of GDB behaved as if "set arm fallback-mode arm".
1778 set disable-randomization
1779 show disable-randomization
1780 Standalone programs run with the virtual address space randomization enabled
1781 by default on some platforms. This option keeps the addresses stable across
1782 multiple debugging sessions.
1786 Control whether other threads are stopped or not when some thread hits
1791 Requests that asynchronous execution is enabled in the target, if available.
1792 In this case, it's possible to resume target in the background, and interact
1793 with GDB while the target is running. "show target-async" displays the
1794 current state of asynchronous execution of the target.
1796 set target-wide-charset
1797 show target-wide-charset
1798 The target-wide-charset is the name of the character set that GDB
1799 uses when printing characters whose type is wchar_t.
1801 set tcp auto-retry (on|off)
1803 set tcp connect-timeout
1804 show tcp connect-timeout
1805 These commands allow GDB to retry failed TCP connections to a remote stub
1806 with a specified timeout period; this is useful if the stub is launched
1807 in parallel with GDB but may not be ready to accept connections immediately.
1809 set libthread-db-search-path
1810 show libthread-db-search-path
1811 Control list of directories which GDB will search for appropriate
1814 set schedule-multiple (on|off)
1815 show schedule-multiple
1816 Allow GDB to resume all threads of all processes or only threads of
1817 the current process.
1821 Use more aggressive caching for accesses to the stack. This improves
1822 performance of remote debugging (particularly backtraces) without
1823 affecting correctness.
1825 set interactive-mode (on|off|auto)
1826 show interactive-mode
1827 Control whether GDB runs in interactive mode (on) or not (off).
1828 When in interactive mode, GDB waits for the user to answer all
1829 queries. Otherwise, GDB does not wait and assumes the default
1830 answer. When set to auto (the default), GDB determines which
1831 mode to use based on the stdin settings.
1836 For program forks, this is replaced by the new more generic `info
1837 inferiors' command. To list checkpoints, you can still use the
1838 `info checkpoints' command, which was an alias for the `info forks'
1842 Replaced by the new `inferior' command. To switch between
1843 checkpoints, you can still use the `restart' command, which was an
1844 alias for the `fork' command.
1847 This is removed, since some targets don't have a notion of
1848 processes. To switch between processes, you can still use the
1849 `inferior' command using GDB's own inferior number.
1852 For program forks, this is replaced by the new more generic `kill
1853 inferior' command. To delete a checkpoint, you can still use the
1854 `delete checkpoint' command, which was an alias for the `delete
1858 For program forks, this is replaced by the new more generic `detach
1859 inferior' command. To detach a checkpoint, you can still use the
1860 `detach checkpoint' command, which was an alias for the `detach
1863 * New native configurations
1865 x86/x86_64 Darwin i[34567]86-*-darwin*
1867 x86_64 MinGW x86_64-*-mingw*
1871 Lattice Mico32 lm32-*
1872 x86 DICOS i[34567]86-*-dicos*
1873 x86_64 DICOS x86_64-*-dicos*
1876 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1877 (mingw32ce) debugging.
1883 These commands were actually not implemented on any target.
1885 *** Changes in GDB 6.8
1887 * New native configurations
1889 NetBSD/hppa hppa*-*netbsd*
1890 Xtensa GNU/Linux xtensa*-*-linux*
1894 NetBSD/hppa hppa*-*-netbsd*
1895 Xtensa GNU/Lunux xtensa*-*-linux*
1897 * Change in command line behavior -- corefiles vs. process ids.
1899 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1900 attaching to process NUMBER fails, GDB no longer attempts to open a
1901 core file named NUMBER. Attaching to a program using the -c option
1902 is no longer supported. Instead, use the '-p' or '--pid' options.
1904 * GDB can now be built as a native debugger for debugging Windows x86
1905 (mingw32) Portable Executable (PE) programs.
1907 * Pending breakpoints no longer change their number when their address
1910 * GDB now supports breakpoints with multiple locations,
1911 including breakpoints on C++ constructors, inside C++ templates,
1912 and in inlined functions.
1914 * GDB's ability to debug optimized code has been improved. GDB more
1915 accurately identifies function bodies and lexical blocks that occupy
1916 more than one contiguous range of addresses.
1918 * Target descriptions can now describe registers for PowerPC.
1920 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1921 registers on PowerPC targets.
1923 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1924 targets even when the libthread_db library is not available.
1926 * The GDB remote stub, gdbserver, now supports the new file transfer
1927 commands (remote put, remote get, and remote delete).
1929 * The GDB remote stub, gdbserver, now supports run and attach in
1930 extended-remote mode.
1932 * hppa*64*-*-hpux11* target broken
1933 The debugger is unable to start a program and fails with the following
1934 error: "Error trying to get information about dynamic linker".
1935 The gdb-6.7 release is also affected.
1937 * GDB now supports the --enable-targets= configure option to allow
1938 building a single GDB executable that supports multiple remote
1939 target architectures.
1941 * GDB now supports debugging C and C++ programs which use the
1942 Decimal Floating Point extension. In addition, the PowerPC target
1943 now has a set of pseudo-registers to inspect decimal float values
1944 stored in two consecutive float registers.
1946 * The -break-insert MI command can optionally create pending
1949 * Improved support for debugging Ada
1950 Many improvements to the Ada language support have been made. These
1952 - Better support for Ada2005 interface types
1953 - Improved handling of arrays and slices in general
1954 - Better support for Taft-amendment types
1955 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1957 - Improved command completion in Ada
1960 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1965 set print frame-arguments (all|scalars|none)
1966 show print frame-arguments
1967 The value of this variable can be changed to control which argument
1968 values should be printed by the debugger when displaying a frame.
1973 Transfer files to and from a remote target, and delete remote files.
1980 Transfer files to and from a remote target, and delete remote files.
1982 * New remote packets
1989 Open, close, read, write, and delete files on the remote system.
1992 Attach to an existing process on the remote system, in extended-remote
1996 Run a new process on the remote system, in extended-remote mode.
1998 *** Changes in GDB 6.7
2000 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2001 bfd, libiberty and opcodes, as revealed by static analysis donated by
2002 Coverity, Inc. (http://scan.coverity.com).
2004 * When looking up multiply-defined global symbols, GDB will now prefer the
2005 symbol definition in the current shared library if it was built using the
2006 -Bsymbolic linker option.
2008 * When the Text User Interface (TUI) is not configured, GDB will now
2009 recognize the -tui command-line option and print a message that the TUI
2012 * The GDB remote stub, gdbserver, now has lower overhead for high
2013 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2015 * GDB for MIPS targets now autodetects whether a remote target provides
2016 32-bit or 64-bit register values.
2018 * Support for C++ member pointers has been improved.
2020 * GDB now understands XML target descriptions, which specify the
2021 target's overall architecture. GDB can read a description from
2022 a local file or over the remote serial protocol.
2024 * Vectors of single-byte data use a new integer type which is not
2025 automatically displayed as character or string data.
2027 * The /s format now works with the print command. It displays
2028 arrays of single-byte integers and pointers to single-byte integers
2031 * Target descriptions can now describe target-specific registers,
2032 for architectures which have implemented the support (currently
2033 only ARM, M68K, and MIPS).
2035 * GDB and the GDB remote stub, gdbserver, now support the XScale
2038 * The GDB remote stub, gdbserver, has been updated to support
2039 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2040 has been rewritten to use the standard GDB remote protocol.
2042 * GDB can now step into C++ functions which are called through thunks.
2044 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2046 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2047 layout. It also supports a TextSeg= and DataSeg= response when only
2048 segment base addresses (rather than offsets) are available.
2050 * The /i format now outputs any trailing branch delay slot instructions
2051 immediately following the last instruction within the count specified.
2053 * The GDB remote protocol "T" stop reply packet now supports a
2054 "library" response. Combined with the new "qXfer:libraries:read"
2055 packet, this response allows GDB to debug shared libraries on targets
2056 where the operating system manages the list of loaded libraries (e.g.
2057 Windows and SymbianOS).
2059 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2060 (DLLs) on Windows and Windows CE targets.
2062 * GDB now supports a faster verification that a .debug file matches its binary
2063 according to its build-id signature, if the signature is present.
2069 Enable or disable hardware flow control (RTS/CTS) on the serial port
2070 when debugging using remote targets.
2072 set mem inaccessible-by-default
2073 show mem inaccessible-by-default
2074 If the target supplies a memory map, for instance via the remote
2075 protocol's "qXfer:memory-map:read" packet, setting this variable
2076 prevents GDB from accessing memory outside the memory map. This
2077 is useful for targets with memory mapped registers or which react
2078 badly to accesses of unmapped address space.
2080 set breakpoint auto-hw
2081 show breakpoint auto-hw
2082 If the target supplies a memory map, for instance via the remote
2083 protocol's "qXfer:memory-map:read" packet, setting this variable
2084 lets GDB use hardware breakpoints automatically for memory regions
2085 where it can not use software breakpoints. This covers both the
2086 "break" command and internal breakpoints used for other commands
2087 including "next" and "finish".
2090 catch exception unhandled
2091 Stop the program execution when Ada exceptions are raised.
2094 Stop the program execution when an Ada assertion failed.
2098 Set an alternate system root for target files. This is a more
2099 general version of "set solib-absolute-prefix", which is now
2100 an alias to "set sysroot".
2103 Provide extended SPU facility status information. This set of
2104 commands is available only when debugging the Cell/B.E. SPU
2107 * New native configurations
2109 OpenBSD/sh sh*-*openbsd*
2112 unset tdesc filename
2114 Use the specified local file as an XML target description, and do
2115 not query the target for its built-in description.
2119 OpenBSD/sh sh*-*-openbsd*
2120 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2121 Toshiba Media Processor mep-elf
2123 * New remote packets
2126 Ignore the specified signals; pass them directly to the debugged program
2127 without stopping other threads or reporting them to GDB.
2129 qXfer:features:read:
2130 Read an XML target description from the target, which describes its
2135 Read or write contents of an spufs file on the target system. These
2136 packets are available only on the Cell/B.E. SPU architecture.
2138 qXfer:libraries:read:
2139 Report the loaded shared libraries. Combined with new "T" packet
2140 response, this packet allows GDB to debug shared libraries on
2141 targets where the operating system manages the list of loaded
2142 libraries (e.g. Windows and SymbianOS).
2146 Support for these obsolete configurations has been removed.
2154 i[34567]86-*-lynxos*
2155 i[34567]86-*-netware*
2156 i[34567]86-*-sco3.2v5*
2157 i[34567]86-*-sco3.2v4*
2159 i[34567]86-*-sysv4.2*
2162 i[34567]86-*-unixware2*
2163 i[34567]86-*-unixware*
2172 * Other removed features
2179 Various m68k-only ROM monitors.
2186 Various Renesas ROM monitors and debugging interfaces for SH and
2191 Support for a Macraigor serial interface to on-chip debugging.
2192 GDB does not directly support the newer parallel or USB
2197 A debug information format. The predecessor to DWARF 2 and
2198 DWARF 3, which are still supported.
2200 Support for the HP aCC compiler on HP-UX/PA-RISC
2202 SOM-encapsulated symbolic debugging information, automatic
2203 invocation of pxdb, and the aCC custom C++ ABI. This does not
2204 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2205 with aCC can still be debugged on an assembly level.
2207 MIPS ".pdr" sections
2209 A MIPS-specific format used to describe stack frame layout
2210 in debugging information.
2214 GDB could work with an older version of Guile to debug
2215 the interpreter and Scheme programs running in it.
2217 set mips stack-arg-size
2218 set mips saved-gpreg-size
2220 Use "set mips abi" to control parameter passing for MIPS.
2222 *** Changes in GDB 6.6
2227 Cell Broadband Engine SPU spu-elf
2229 * GDB can now be configured as a cross-debugger targeting native Windows
2230 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2231 running on a Windows system over TCP/IP to debug Windows programs.
2233 * The GDB remote stub, gdbserver, has been updated to support Windows and
2234 Cygwin debugging. Both single-threaded and multi-threaded programs are
2237 * The "set trust-readonly-sections" command works again. This command was
2238 broken in GDB 6.3, 6.4, and 6.5.
2240 * The "load" command now supports writing to flash memory, if the remote
2241 stub provides the required support.
2243 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2244 longer requires symbolic debug information (e.g. DWARF-2).
2249 unset substitute-path
2250 show substitute-path
2251 Manage a list of substitution rules that GDB uses to rewrite the name
2252 of the directories where the sources are located. This can be useful
2253 for instance when the sources were moved to a different location
2254 between compilation and debugging.
2258 Print each CLI command as it is executed. Each command is prefixed with
2259 a number of `+' symbols representing the nesting depth.
2260 The source command now has a `-v' option to enable the same feature.
2264 The ARM Demon monitor support (RDP protocol, "target rdp").
2266 Kernel Object Display, an embedded debugging feature which only worked with
2267 an obsolete version of Cisco IOS.
2269 The 'set download-write-size' and 'show download-write-size' commands.
2271 * New remote packets
2274 Tell a stub about GDB client features, and request remote target features.
2275 The first feature implemented is PacketSize, which allows the target to
2276 specify the size of packets it can handle - to minimize the number of
2277 packets required and improve performance when connected to a remote
2281 Fetch an OS auxilliary vector from the remote stub. This packet is a
2282 more efficient replacement for qPart:auxv:read.
2284 qXfer:memory-map:read:
2285 Fetch a memory map from the remote stub, including information about
2286 RAM, ROM, and flash memory devices.
2291 Erase and program a flash memory device.
2293 * Removed remote packets
2296 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2297 used it, and only gdbserver implemented it.
2299 *** Changes in GDB 6.5
2303 Renesas M32C/M16C m32c-elf
2305 Morpho Technologies ms1 ms1-elf
2309 init-if-undefined Initialize a convenience variable, but
2310 only if it doesn't already have a value.
2312 The following commands are presently only implemented for native GNU/Linux:
2314 checkpoint Save a snapshot of the program state.
2316 restart <n> Return the program state to a
2317 previously saved state.
2319 info checkpoints List currently saved checkpoints.
2321 delete-checkpoint <n> Delete a previously saved checkpoint.
2323 set|show detach-on-fork Tell gdb whether to detach from a newly
2324 forked process, or to keep debugging it.
2326 info forks List forks of the user program that
2327 are available to be debugged.
2329 fork <n> Switch to debugging one of several
2330 forks of the user program that are
2331 available to be debugged.
2333 delete-fork <n> Delete a fork from the list of forks
2334 that are available to be debugged (and
2335 kill the forked process).
2337 detach-fork <n> Delete a fork from the list of forks
2338 that are available to be debugged (and
2339 allow the process to continue).
2343 Morpho Technologies ms2 ms1-elf
2345 * Improved Windows host support
2347 GDB now builds as a cross debugger hosted on i686-mingw32, including
2348 native console support, and remote communications using either
2349 network sockets or serial ports.
2351 * Improved Modula-2 language support
2353 GDB can now print most types in the Modula-2 syntax. This includes:
2354 basic types, set types, record types, enumerated types, range types,
2355 pointer types and ARRAY types. Procedure var parameters are correctly
2356 printed and hexadecimal addresses and character constants are also
2357 written in the Modula-2 syntax. Best results can be obtained by using
2358 GNU Modula-2 together with the -gdwarf-2 command line option.
2362 The ARM rdi-share module.
2364 The Netware NLM debug server.
2366 *** Changes in GDB 6.4
2368 * New native configurations
2370 OpenBSD/arm arm*-*-openbsd*
2371 OpenBSD/mips64 mips64-*-openbsd*
2375 Morpho Technologies ms1 ms1-elf
2377 * New command line options
2379 --batch-silent As for --batch, but totally silent.
2380 --return-child-result The debugger will exist with the same value
2381 the child (debugged) program exited with.
2382 --eval-command COMMAND, -ex COMMAND
2383 Execute a single GDB CLI command. This may be
2384 specified multiple times and in conjunction
2385 with the --command (-x) option.
2387 * Deprecated commands removed
2389 The following commands, that were deprecated in 2000, have been
2393 set|show arm disassembly-flavor set|show arm disassembler
2394 othernames set arm disassembler
2395 set|show remotedebug set|show debug remote
2396 set|show archdebug set|show debug arch
2397 set|show eventdebug set|show debug event
2400 * New BSD user-level threads support
2402 It is now possible to debug programs using the user-level threads
2403 library on OpenBSD and FreeBSD. Currently supported (target)
2406 FreeBSD/amd64 x86_64-*-freebsd*
2407 FreeBSD/i386 i386-*-freebsd*
2408 OpenBSD/i386 i386-*-openbsd*
2410 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2411 are not yet supported.
2413 * New support for Matsushita MN10300 w/sim added
2414 (Work in progress). mn10300-elf.
2416 * REMOVED configurations and files
2418 VxWorks and the XDR protocol *-*-vxworks
2419 Motorola MCORE mcore-*-*
2420 National Semiconductor NS32000 ns32k-*-*
2422 * New "set print array-indexes" command
2424 After turning this setting "on", GDB prints the index of each element
2425 when displaying arrays. The default is "off" to preserve the previous
2428 * VAX floating point support
2430 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2432 * User-defined command support
2434 In addition to using $arg0..$arg9 for argument passing, it is now possible
2435 to use $argc to determine now many arguments have been passed. See the
2436 section on user-defined commands in the user manual for more information.
2438 *** Changes in GDB 6.3:
2440 * New command line option
2442 GDB now accepts -l followed by a number to set the timeout for remote
2445 * GDB works with GCC -feliminate-dwarf2-dups
2447 GDB now supports a more compact representation of DWARF-2 debug
2448 information using DW_FORM_ref_addr references. These are produced
2449 by GCC with the option -feliminate-dwarf2-dups and also by some
2450 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2451 to use -feliminate-dwarf2-dups.
2453 * Internationalization
2455 When supported by the host system, GDB will be built with
2456 internationalization (libintl). The task of marking up the sources is
2457 continued, we're looking forward to our first translation.
2461 Initial support for debugging programs compiled with the GNAT
2462 implementation of the Ada programming language has been integrated
2463 into GDB. In this release, support is limited to expression evaluation.
2465 * New native configurations
2467 GNU/Linux/m32r m32r-*-linux-gnu
2471 GDB's remote protocol now includes support for the 'p' packet. This
2472 packet is used to fetch individual registers from a remote inferior.
2474 * END-OF-LIFE registers[] compatibility module
2476 GDB's internal register infrastructure has been completely rewritten.
2477 The new infrastructure making possible the implementation of key new
2478 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2481 GDB 6.3 will be the last release to include the the registers[]
2482 compatibility module that allowed out-of-date configurations to
2483 continue to work. This change directly impacts the following
2493 powerpc bdm protocol
2495 Unless there is activity to revive these configurations, they will be
2496 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2498 * OBSOLETE configurations and files
2500 Configurations that have been declared obsolete in this release have
2501 been commented out. Unless there is activity to revive these
2502 configurations, the next release of GDB will have their sources
2503 permanently REMOVED.
2512 *** Changes in GDB 6.2.1:
2514 * MIPS `break main; run' gave an heuristic-fence-post warning
2516 When attempting to run even a simple program, a warning about
2517 heuristic-fence-post being hit would be reported. This problem has
2520 * MIPS IRIX 'long double' crashed GDB
2522 When examining a long double variable, GDB would get a segmentation
2523 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2524 IRIX long double values).
2528 A bug in the VAX stack code was causing problems with the "next"
2529 command. This problem has been fixed.
2531 *** Changes in GDB 6.2:
2533 * Fix for ``many threads''
2535 On GNU/Linux systems that use the NPTL threads library, a program
2536 rapidly creating and deleting threads would confuse GDB leading to the
2539 ptrace: No such process.
2540 thread_db_get_info: cannot get thread info: generic error
2542 This problem has been fixed.
2544 * "-async" and "-noasync" options removed.
2546 Support for the broken "-noasync" option has been removed (it caused
2549 * New ``start'' command.
2551 This command runs the program until the begining of the main procedure.
2553 * New BSD Kernel Data Access Library (libkvm) interface
2555 Using ``target kvm'' it is now possible to debug kernel core dumps and
2556 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2557 platforms. Currently supported (native-only) configurations are:
2559 FreeBSD/amd64 x86_64-*-freebsd*
2560 FreeBSD/i386 i?86-*-freebsd*
2561 NetBSD/i386 i?86-*-netbsd*
2562 NetBSD/m68k m68*-*-netbsd*
2563 NetBSD/sparc sparc-*-netbsd*
2564 OpenBSD/amd64 x86_64-*-openbsd*
2565 OpenBSD/i386 i?86-*-openbsd*
2566 OpenBSD/m68k m68*-openbsd*
2567 OpenBSD/sparc sparc-*-openbsd*
2569 * Signal trampoline code overhauled
2571 Many generic problems with GDB's signal handling code have been fixed.
2572 These include: backtraces through non-contiguous stacks; recognition
2573 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2574 call; backtrace through a signal trampoline; step into and out of
2575 signal handlers; and single-stepping in the signal trampoline.
2577 Please note that kernel bugs are a limiting factor here. These
2578 features have been shown to work on an s390 GNU/Linux system that
2579 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2581 * Cygwin support for DWARF 2 added.
2583 * New native configurations
2585 GNU/Linux/hppa hppa*-*-linux*
2586 OpenBSD/hppa hppa*-*-openbsd*
2587 OpenBSD/m68k m68*-*-openbsd*
2588 OpenBSD/m88k m88*-*-openbsd*
2589 OpenBSD/powerpc powerpc-*-openbsd*
2590 NetBSD/vax vax-*-netbsd*
2591 OpenBSD/vax vax-*-openbsd*
2593 * END-OF-LIFE frame compatibility module
2595 GDB's internal frame infrastructure has been completely rewritten.
2596 The new infrastructure making it possible to support key new features
2597 including DWARF 2 Call Frame Information. To aid in the task of
2598 migrating old configurations to this new infrastructure, a
2599 compatibility module, that allowed old configurations to continue to
2600 work, was also included.
2602 GDB 6.2 will be the last release to include this frame compatibility
2603 module. This change directly impacts the following configurations:
2613 Unless there is activity to revive these configurations, they will be
2614 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2616 * REMOVED configurations and files
2618 Sun 3, running SunOS 3 m68*-*-sunos3*
2619 Sun 3, running SunOS 4 m68*-*-sunos4*
2620 Sun 2, running SunOS 3 m68000-*-sunos3*
2621 Sun 2, running SunOS 4 m68000-*-sunos4*
2622 Motorola 680x0 running LynxOS m68*-*-lynxos*
2623 AT&T 3b1/Unix pc m68*-att-*
2624 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2625 decstation mips-dec-* mips-little-*
2626 riscos mips-*-riscos* mips-*-sysv*
2627 sonymips mips-sony-*
2628 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2630 *** Changes in GDB 6.1.1:
2632 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2634 The TUI (Text-mode User Interface) is now built as part of a default
2635 GDB configuration. It is enabled by either selecting the TUI with the
2636 command line option "-i=tui" or by running the separate "gdbtui"
2637 program. For more information on the TUI, see the manual "Debugging
2640 * Pending breakpoint support (also included in GDB 6.1)
2642 Support has been added to allow you to specify breakpoints in shared
2643 libraries that have not yet been loaded. If a breakpoint location
2644 cannot be found, and the "breakpoint pending" option is set to auto,
2645 GDB queries you if you wish to make the breakpoint pending on a future
2646 shared-library load. If and when GDB resolves the breakpoint symbol,
2647 the pending breakpoint is removed as one or more regular breakpoints
2650 Pending breakpoints are very useful for GCJ Java debugging.
2652 * Fixed ISO-C build problems
2654 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2655 non ISO-C code that stopped them being built using a more strict ISO-C
2656 compiler (e.g., IBM's C compiler).
2658 * Fixed build problem on IRIX 5
2660 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2661 wasn't able to compile compile on an IRIX 5 system.
2663 * Added execute permission to gdb/gdbserver/configure
2665 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2666 permission. This bug would cause configure to fail on a number of
2667 systems (Solaris, IRIX). Ref: server/519.
2669 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2671 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2672 has been updated to use constant array sizes.
2674 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2676 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2677 its generated DWARF Call Frame Info. This encoding was causing GDB to
2678 panic, that panic has been fixed. Ref: gdb/1628.
2680 * Fixed a problem when examining parameters in shared library code.
2682 When examining parameters in optimized shared library code generated
2683 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2684 not available''. GDB now correctly displays the variable's value.
2686 *** Changes in GDB 6.1:
2688 * Removed --with-mmalloc
2690 Support for the mmalloc memory manager has been removed, as it
2691 conflicted with the internal gdb byte cache.
2693 * Changes in AMD64 configurations
2695 The AMD64 target now includes the %cs and %ss registers. As a result
2696 the AMD64 remote protocol has changed; this affects the floating-point
2697 and SSE registers. If you rely on those registers for your debugging,
2698 you should upgrade gdbserver on the remote side.
2700 * Revised SPARC target
2702 The SPARC target has been completely revised, incorporating the
2703 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2704 support for LynxOS and SunOS 4 has been dropped. Calling functions
2705 from within GDB on operating systems with a non-executable stack
2706 (Solaris, OpenBSD) now works.
2710 GDB has a new C++ demangler which does a better job on the mangled
2711 names generated by current versions of g++. It also runs faster, so
2712 with this and other changes gdb should now start faster on large C++
2715 * DWARF 2 Location Expressions
2717 GDB support for location expressions has been extended to support function
2718 arguments and frame bases. Older versions of GDB could crash when they
2721 * C++ nested types and namespaces
2723 GDB's support for nested types and namespaces in C++ has been
2724 improved, especially if you use the DWARF 2 debugging format. (This
2725 is the default for recent versions of GCC on most platforms.)
2726 Specifically, if you have a class "Inner" defined within a class or
2727 namespace "Outer", then GDB realizes that the class's name is
2728 "Outer::Inner", not simply "Inner". This should greatly reduce the
2729 frequency of complaints about not finding RTTI symbols. In addition,
2730 if you are stopped at inside of a function defined within a namespace,
2731 GDB modifies its name lookup accordingly.
2733 * New native configurations
2735 NetBSD/amd64 x86_64-*-netbsd*
2736 OpenBSD/amd64 x86_64-*-openbsd*
2737 OpenBSD/alpha alpha*-*-openbsd*
2738 OpenBSD/sparc sparc-*-openbsd*
2739 OpenBSD/sparc64 sparc64-*-openbsd*
2741 * New debugging protocols
2743 M32R with SDI protocol m32r-*-elf*
2745 * "set prompt-escape-char" command deleted.
2747 The command "set prompt-escape-char" has been deleted. This command,
2748 and its very obscure effet on GDB's prompt, was never documented,
2749 tested, nor mentioned in the NEWS file.
2751 * OBSOLETE configurations and files
2753 Configurations that have been declared obsolete in this release have
2754 been commented out. Unless there is activity to revive these
2755 configurations, the next release of GDB will have their sources
2756 permanently REMOVED.
2758 Sun 3, running SunOS 3 m68*-*-sunos3*
2759 Sun 3, running SunOS 4 m68*-*-sunos4*
2760 Sun 2, running SunOS 3 m68000-*-sunos3*
2761 Sun 2, running SunOS 4 m68000-*-sunos4*
2762 Motorola 680x0 running LynxOS m68*-*-lynxos*
2763 AT&T 3b1/Unix pc m68*-att-*
2764 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2765 decstation mips-dec-* mips-little-*
2766 riscos mips-*-riscos* mips-*-sysv*
2767 sonymips mips-sony-*
2768 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2770 * REMOVED configurations and files
2772 SGI Irix-4.x mips-sgi-irix4 or iris4
2773 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2774 Z8000 simulator z8k-zilog-none or z8ksim
2775 Matsushita MN10200 w/simulator mn10200-*-*
2776 H8/500 simulator h8500-hitachi-hms or h8500hms
2777 HP/PA running BSD hppa*-*-bsd*
2778 HP/PA running OSF/1 hppa*-*-osf*
2779 HP/PA Pro target hppa*-*-pro*
2780 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2781 386BSD i[3456]86-*-bsd*
2782 Sequent family i[3456]86-sequent-sysv4*
2783 i[3456]86-sequent-sysv*
2784 i[3456]86-sequent-bsd*
2785 SPARC running LynxOS sparc-*-lynxos*
2786 SPARC running SunOS 4 sparc-*-sunos4*
2787 Tsqware Sparclet sparclet-*-*
2788 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2790 *** Changes in GDB 6.0:
2794 Support for debugging the Objective-C programming language has been
2795 integrated into GDB.
2797 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2799 DWARF 2's Call Frame Information makes available compiler generated
2800 information that more exactly describes the program's run-time stack.
2801 By using this information, GDB is able to provide more robust stack
2804 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2805 have been updated to use a new backtrace mechanism which includes
2806 DWARF 2 CFI support.
2810 GDB's remote protocol has been extended to include support for hosted
2811 file I/O (where the remote target uses GDB's file system). See GDB's
2812 remote protocol documentation for details.
2814 * All targets using the new architecture framework.
2816 All of GDB's targets have been updated to use the new internal
2817 architecture framework. The way is now open for future GDB releases
2818 to include cross-architecture native debugging support (i386 on amd64,
2821 * GNU/Linux's Thread Local Storage (TLS)
2823 GDB now includes support for for the GNU/Linux implementation of
2824 per-thread variables.
2826 * GNU/Linux's Native POSIX Thread Library (NPTL)
2828 GDB's thread code has been updated to work with either the new
2829 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2831 * Separate debug info.
2833 GDB, in conjunction with BINUTILS, now supports a mechanism for
2834 automatically loading debug information from a separate file. Instead
2835 of shipping full debug and non-debug versions of system libraries,
2836 system integrators can now instead ship just the stripped libraries
2837 and optional debug files.
2839 * DWARF 2 Location Expressions
2841 DWARF 2 Location Expressions allow the compiler to more completely
2842 describe the location of variables (even in optimized code) to the
2845 GDB now includes preliminary support for location expressions (support
2846 for DW_OP_piece is still missing).
2850 A number of long standing bugs that caused GDB to die while starting a
2851 Java application have been fixed. GDB's Java support is now
2852 considered "useable".
2854 * GNU/Linux support for fork, vfork, and exec.
2856 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2857 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2860 * GDB supports logging output to a file
2862 There are two new commands, "set logging" and "show logging", which can be
2863 used to capture GDB's output to a file.
2865 * The meaning of "detach" has changed for gdbserver
2867 The "detach" command will now resume the application, as documented. To
2868 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2871 * d10v, m68hc11 `regs' command deprecated
2873 The `info registers' command has been updated so that it displays the
2874 registers using a format identical to the old `regs' command.
2878 A new command, "maint set profile on/off", has been added. This command can
2879 be used to enable or disable profiling while running GDB, to profile a
2880 session or a set of commands. In addition there is a new configure switch,
2881 "--enable-profiling", which will cause GDB to be compiled with profiling
2882 data, for more informative profiling results.
2884 * Default MI syntax changed to "mi2".
2886 The default MI (machine interface) syntax, enabled by the command line
2887 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2888 "mi1", can be enabled by specifying the option "-i=mi1".
2890 Support for the original "mi0" syntax (included in GDB 5.0) has been
2893 Fix for gdb/192: removed extraneous space when displaying frame level.
2894 Fix for gdb/672: update changelist is now output in mi list format.
2895 Fix for gdb/702: a -var-assign that updates the value now shows up
2896 in a subsequent -var-update.
2898 * New native configurations.
2900 FreeBSD/amd64 x86_64-*-freebsd*
2902 * Multi-arched targets.
2904 HP/PA HPUX11 hppa*-*-hpux*
2905 Renesas M32R/D w/simulator m32r-*-elf*
2907 * OBSOLETE configurations and files
2909 Configurations that have been declared obsolete in this release have
2910 been commented out. Unless there is activity to revive these
2911 configurations, the next release of GDB will have their sources
2912 permanently REMOVED.
2914 Z8000 simulator z8k-zilog-none or z8ksim
2915 Matsushita MN10200 w/simulator mn10200-*-*
2916 H8/500 simulator h8500-hitachi-hms or h8500hms
2917 HP/PA running BSD hppa*-*-bsd*
2918 HP/PA running OSF/1 hppa*-*-osf*
2919 HP/PA Pro target hppa*-*-pro*
2920 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2921 Sequent family i[3456]86-sequent-sysv4*
2922 i[3456]86-sequent-sysv*
2923 i[3456]86-sequent-bsd*
2924 Tsqware Sparclet sparclet-*-*
2925 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2927 * REMOVED configurations and files
2930 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2931 IBM AIX PS/2 i[3456]86-*-aix
2932 i386 running Mach 3.0 i[3456]86-*-mach3*
2933 i386 running Mach i[3456]86-*-mach*
2934 i386 running OSF/1 i[3456]86-*osf1mk*
2935 HP/Apollo 68k Family m68*-apollo*-sysv*,
2937 m68*-hp-bsd*, m68*-hp-hpux*
2938 Argonaut Risc Chip (ARC) arc-*-*
2939 Mitsubishi D30V d30v-*-*
2940 Fujitsu FR30 fr30-*-elf*
2941 OS/9000 i[34]86-*-os9k
2942 I960 with MON960 i960-*-coff
2944 * MIPS $fp behavior changed
2946 The convenience variable $fp, for the MIPS, now consistently returns
2947 the address of the current frame's base. Previously, depending on the
2948 context, $fp could refer to either $sp or the current frame's base
2949 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2950 The GNU Source-Level Debugger''.
2952 *** Changes in GDB 5.3:
2954 * GNU/Linux shared library multi-threaded performance improved.
2956 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2957 `/proc', in preference to `ptrace' for memory reads. This may result
2958 in an improvement in the start-up time of multi-threaded, shared
2959 library applications when run under GDB. One GDB user writes: ``loads
2960 shared libs like mad''.
2962 * ``gdbserver'' now supports multi-threaded applications on some targets
2964 Support for debugging multi-threaded applications which use
2965 the GNU/Linux LinuxThreads package has been added for
2966 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2967 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2969 * GDB now supports C/C++ preprocessor macros.
2971 GDB now expands preprocessor macro invocations in C/C++ expressions,
2972 and provides various commands for showing macro definitions and how
2975 The new command `macro expand EXPRESSION' expands any macro
2976 invocations in expression, and shows the result.
2978 The new command `show macro MACRO-NAME' shows the definition of the
2979 macro named MACRO-NAME, and where it was defined.
2981 Most compilers don't include information about macros in the debugging
2982 information by default. In GCC 3.1, for example, you need to compile
2983 your program with the options `-gdwarf-2 -g3'. If the macro
2984 information is present in the executable, GDB will read it.
2986 * Multi-arched targets.
2988 DEC Alpha (partial) alpha*-*-*
2989 DEC VAX (partial) vax-*-*
2991 National Semiconductor NS32000 (partial) ns32k-*-*
2992 Motorola 68000 (partial) m68k-*-*
2993 Motorola MCORE mcore-*-*
2997 Fujitsu FRV architecture added by Red Hat frv*-*-*
3000 * New native configurations
3002 Alpha NetBSD alpha*-*-netbsd*
3003 SH NetBSD sh*-*-netbsdelf*
3004 MIPS NetBSD mips*-*-netbsd*
3005 UltraSPARC NetBSD sparc64-*-netbsd*
3007 * OBSOLETE configurations and files
3009 Configurations that have been declared obsolete in this release have
3010 been commented out. Unless there is activity to revive these
3011 configurations, the next release of GDB will have their sources
3012 permanently REMOVED.
3014 Mitsubishi D30V d30v-*-*
3015 OS/9000 i[34]86-*-os9k
3016 IBM AIX PS/2 i[3456]86-*-aix
3017 Fujitsu FR30 fr30-*-elf*
3018 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3019 Argonaut Risc Chip (ARC) arc-*-*
3020 i386 running Mach 3.0 i[3456]86-*-mach3*
3021 i386 running Mach i[3456]86-*-mach*
3022 i386 running OSF/1 i[3456]86-*osf1mk*
3023 HP/Apollo 68k Family m68*-apollo*-sysv*,
3025 m68*-hp-bsd*, m68*-hp-hpux*
3026 I960 with MON960 i960-*-coff
3028 * OBSOLETE languages
3030 CHILL, a Pascal like language used by telecommunications companies.
3032 * REMOVED configurations and files
3034 AMD 29k family via UDI a29k-amd-udi, udi29k
3035 A29K VxWorks a29k-*-vxworks
3036 AMD 29000 embedded, using EBMON a29k-none-none
3037 AMD 29000 embedded with COFF a29k-none-coff
3038 AMD 29000 embedded with a.out a29k-none-aout
3040 testsuite/gdb.hp/gdb.threads-hp/ directory
3042 * New command "set max-user-call-depth <nnn>"
3044 This command allows the user to limit the call depth of user-defined
3045 commands. The default is 1024.
3047 * Changes in FreeBSD/i386 native debugging.
3049 Support for the "generate-core-file" has been added.
3051 * New commands "dump", "append", and "restore".
3053 These commands allow data to be copied from target memory
3054 to a bfd-format or binary file (dump and append), and back
3055 from a file into memory (restore).
3057 * Improved "next/step" support on multi-processor Alpha Tru64.
3059 The previous single-step mechanism could cause unpredictable problems,
3060 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3061 of a software single-step mechanism prevents this.
3063 *** Changes in GDB 5.2.1:
3071 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3072 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3073 Fix, by Joel Brobecker imported from mainline.
3075 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3076 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3077 Fix, by Fred Fish, imported from mainline.
3079 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3080 Surprisingly enough, it works now.
3081 By Michal Ludvig, imported from mainline.
3083 i386 hardware watchpoint support:
3084 avoid misses on second run for some targets.
3085 By Pierre Muller, imported from mainline.
3087 *** Changes in GDB 5.2:
3089 * New command "set trust-readonly-sections on[off]".
3091 This command is a hint that tells gdb that read-only sections
3092 really are read-only (ie. that their contents will not change).
3093 In this mode, gdb will go to the object file rather than the
3094 target to read memory from read-only sections (such as ".text").
3095 This can be a significant performance improvement on some
3096 (notably embedded) targets.
3098 * New command "generate-core-file" (or "gcore").
3100 This new gdb command allows the user to drop a core file of the child
3101 process state at any time. So far it's been implemented only for
3102 GNU/Linux and Solaris, but should be relatively easily ported to other
3103 hosts. Argument is core file name (defaults to core.<pid>).
3105 * New command line option
3107 GDB now accepts --pid or -p followed by a process id.
3109 * Change in command line behavior -- corefiles vs. process ids.
3111 There is a subtle behavior in the way in which GDB handles
3112 command line arguments. The first non-flag argument is always
3113 a program to debug, but the second non-flag argument may either
3114 be a corefile or a process id. Previously, GDB would attempt to
3115 open the second argument as a corefile, and if that failed, would
3116 issue a superfluous error message and then attempt to attach it as
3117 a process. Now, if the second argument begins with a non-digit,
3118 it will be treated as a corefile. If it begins with a digit,
3119 GDB will attempt to attach it as a process, and if no such process
3120 is found, will then attempt to open it as a corefile.
3122 * Changes in ARM configurations.
3124 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3125 configuration is fully multi-arch.
3127 * New native configurations
3129 ARM NetBSD arm*-*-netbsd*
3130 x86 OpenBSD i[3456]86-*-openbsd*
3131 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3132 Sparc64 running FreeBSD sparc64-*-freebsd*
3136 Sanyo XStormy16 xstormy16-elf
3138 * OBSOLETE configurations and files
3140 Configurations that have been declared obsolete in this release have
3141 been commented out. Unless there is activity to revive these
3142 configurations, the next release of GDB will have their sources
3143 permanently REMOVED.
3145 AMD 29k family via UDI a29k-amd-udi, udi29k
3146 A29K VxWorks a29k-*-vxworks
3147 AMD 29000 embedded, using EBMON a29k-none-none
3148 AMD 29000 embedded with COFF a29k-none-coff
3149 AMD 29000 embedded with a.out a29k-none-aout
3151 testsuite/gdb.hp/gdb.threads-hp/ directory
3153 * REMOVED configurations and files
3155 TI TMS320C80 tic80-*-*
3157 PowerPC Solaris powerpcle-*-solaris*
3158 PowerPC Windows NT powerpcle-*-cygwin32
3159 PowerPC Netware powerpc-*-netware*
3160 Harris/CXUX m88k m88*-harris-cxux*
3161 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3162 ns32k-utek-sysv* ns32k-utek-*
3163 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3164 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3165 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3166 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3167 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3169 * Changes to command line processing
3171 The new `--args' feature can be used to specify command-line arguments
3172 for the inferior from gdb's command line.
3174 * Changes to key bindings
3176 There is a new `operate-and-get-next' function bound to `C-o'.
3178 *** Changes in GDB 5.1.1
3180 Fix compile problem on DJGPP.
3182 Fix a problem with floating-point registers on the i386 being
3185 Fix to stop GDB crashing on .debug_str debug info.
3187 Numerous documentation fixes.
3189 Numerous testsuite fixes.
3191 *** Changes in GDB 5.1:
3193 * New native configurations
3195 Alpha FreeBSD alpha*-*-freebsd*
3196 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3197 MIPS GNU/Linux mips*-*-linux*
3198 MIPS SGI Irix 6.x mips*-sgi-irix6*
3199 ia64 AIX ia64-*-aix*
3200 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3204 Motorola 68HC11 and 68HC12 m68hc11-elf
3206 UltraSparc running GNU/Linux sparc64-*-linux*
3208 * OBSOLETE configurations and files
3210 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3211 Harris/CXUX m88k m88*-harris-cxux*
3212 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3213 ns32k-utek-sysv* ns32k-utek-*
3214 TI TMS320C80 tic80-*-*
3216 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3217 PowerPC Solaris powerpcle-*-solaris*
3218 PowerPC Windows NT powerpcle-*-cygwin32
3219 PowerPC Netware powerpc-*-netware*
3220 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3221 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3222 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3223 Apple Macintosh (MPW) host N/A
3225 stuff.c (Program to stuff files into a specially prepared space in kdb)
3226 kdb-start.c (Main loop for the standalone kernel debugger)
3228 Configurations that have been declared obsolete in this release have
3229 been commented out. Unless there is activity to revive these
3230 configurations, the next release of GDB will have their sources
3231 permanently REMOVED.
3233 * REMOVED configurations and files
3235 Altos 3068 m68*-altos-*
3236 Convex c1-*-*, c2-*-*
3238 ARM RISCix arm-*-* (as host)
3242 * GDB has been converted to ISO C.
3244 GDB's source code has been converted to ISO C. In particular, the
3245 sources are fully protoized, and rely on standard headers being
3250 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3252 * The MI enabled by default.
3254 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3255 revised and enabled by default. Packages which use GDB as a debugging
3256 engine behind a UI or another front end are encouraged to switch to
3257 using the GDB/MI interface, instead of the old annotations interface
3258 which is now deprecated.
3260 * Support for debugging Pascal programs.
3262 GDB now includes support for debugging Pascal programs. The following
3263 main features are supported:
3265 - Pascal-specific data types such as sets;
3267 - automatic recognition of Pascal sources based on file-name
3270 - Pascal-style display of data types, variables, and functions;
3272 - a Pascal expression parser.
3274 However, some important features are not yet supported.
3276 - Pascal string operations are not supported at all;
3278 - there are some problems with boolean types;
3280 - Pascal type hexadecimal constants are not supported
3281 because they conflict with the internal variables format;
3283 - support for Pascal objects and classes is not full yet;
3285 - unlike Pascal, GDB is case-sensitive for symbol names.
3287 * Changes in completion.
3289 Commands such as `shell', `run' and `set args', which pass arguments
3290 to inferior programs, now complete on file names, similar to what
3291 users expect at the shell prompt.
3293 Commands which accept locations, such as `disassemble', `print',
3294 `breakpoint', `until', etc. now complete on filenames as well as
3295 program symbols. Thus, if you type "break foob TAB", and the source
3296 files linked into the programs include `foobar.c', that file name will
3297 be one of the candidates for completion. However, file names are not
3298 considered for completion after you typed a colon that delimits a file
3299 name from a name of a function in that file, as in "break foo.c:bar".
3301 `set demangle-style' completes on available demangling styles.
3303 * New platform-independent commands:
3305 It is now possible to define a post-hook for a command as well as a
3306 hook that runs before the command. For more details, see the
3307 documentation of `hookpost' in the GDB manual.
3309 * Changes in GNU/Linux native debugging.
3311 Support for debugging multi-threaded programs has been completely
3312 revised for all platforms except m68k and sparc. You can now debug as
3313 many threads as your system allows you to have.
3315 Attach/detach is supported for multi-threaded programs.
3317 Support for SSE registers was added for x86. This doesn't work for
3318 multi-threaded programs though.
3320 * Changes in MIPS configurations.
3322 Multi-arch support is enabled for all MIPS configurations.
3324 GDB can now be built as native debugger on SGI Irix 6.x systems for
3325 debugging n32 executables. (Debugging 64-bit executables is not yet
3328 * Unified support for hardware watchpoints in all x86 configurations.
3330 Most (if not all) native x86 configurations support hardware-assisted
3331 breakpoints and watchpoints in a unified manner. This support
3332 implements debug register sharing between watchpoints, which allows to
3333 put a virtually infinite number of watchpoints on the same address,
3334 and also supports watching regions up to 16 bytes with several debug
3337 The new maintenance command `maintenance show-debug-regs' toggles
3338 debugging print-outs in functions that insert, remove, and test
3339 watchpoints and hardware breakpoints.
3341 * Changes in the DJGPP native configuration.
3343 New command ``info dos sysinfo'' displays assorted information about
3344 the CPU, OS, memory, and DPMI server.
3346 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3347 display information about segment descriptors stored in GDT, LDT, and
3350 New commands ``info dos pde'' and ``info dos pte'' display entries
3351 from Page Directory and Page Tables (for now works with CWSDPMI only).
3352 New command ``info dos address-pte'' displays the Page Table entry for
3353 a given linear address.
3355 GDB can now pass command lines longer than 126 characters to the
3356 program being debugged (requires an update to the libdbg.a library
3357 which is part of the DJGPP development kit).
3359 DWARF2 debug info is now supported.
3361 It is now possible to `step' and `next' through calls to `longjmp'.
3363 * Changes in documentation.
3365 All GDB documentation was converted to GFDL, the GNU Free
3366 Documentation License.
3368 Tracepoints-related commands are now fully documented in the GDB
3371 TUI, the Text-mode User Interface, is now documented in the manual.
3373 Tracepoints-related commands are now fully documented in the GDB
3376 The "GDB Internals" manual now has an index. It also includes
3377 documentation of `ui_out' functions, GDB coding standards, x86
3378 hardware watchpoints, and memory region attributes.
3380 * GDB's version number moved to ``version.in''
3382 The Makefile variable VERSION has been replaced by the file
3383 ``version.in''. People creating GDB distributions should update the
3384 contents of this file.
3388 GUD support is now a standard part of the EMACS distribution.
3390 *** Changes in GDB 5.0:
3392 * Improved support for debugging FP programs on x86 targets
3394 Unified and much-improved support for debugging floating-point
3395 programs on all x86 targets. In particular, ``info float'' now
3396 displays the FP registers in the same format on all x86 targets, with
3397 greater level of detail.
3399 * Improvements and bugfixes in hardware-assisted watchpoints
3401 It is now possible to watch array elements, struct members, and
3402 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3403 on x86 targets no longer erroneously trigger when the address is
3406 * Improvements in the native DJGPP version of GDB
3408 The distribution now includes all the scripts and auxiliary files
3409 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3410 machines ``out of the box''.
3412 The DJGPP version can now debug programs that use signals. It is
3413 possible to catch signals that happened in the debuggee, deliver
3414 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3415 would kill the program being debugged.) Programs that hook hardware
3416 interrupts (keyboard, timer, etc.) can also be debugged.
3418 It is now possible to debug DJGPP programs that redirect their
3419 standard handles or switch them to raw (as opposed to cooked) mode, or
3420 even close them. The command ``run < foo > bar'' works as expected,
3421 and ``info terminal'' reports useful information about the debuggee's
3422 terminal, including raw/cooked mode, redirection, etc.
3424 The DJGPP version now uses termios functions for console I/O, which
3425 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3428 DOS-style file names with drive letters are now fully supported by
3431 It is now possible to debug DJGPP programs that switch their working
3432 directory. It is also possible to rerun the debuggee any number of
3433 times without restarting GDB; thus, you can use the same setup,
3434 breakpoints, etc. for many debugging sessions.
3436 * New native configurations
3438 ARM GNU/Linux arm*-*-linux*
3439 PowerPC GNU/Linux powerpc-*-linux*
3443 Motorola MCore mcore-*-*
3444 x86 VxWorks i[3456]86-*-vxworks*
3445 PowerPC VxWorks powerpc-*-vxworks*
3446 TI TMS320C80 tic80-*-*
3448 * OBSOLETE configurations
3450 Altos 3068 m68*-altos-*
3451 Convex c1-*-*, c2-*-*
3453 ARM RISCix arm-*-* (as host)
3456 Configurations that have been declared obsolete will be commented out,
3457 but the code will be left in place. If there is no activity to revive
3458 these configurations before the next release of GDB, the sources will
3459 be permanently REMOVED.
3461 * Gould support removed
3463 Support for the Gould PowerNode and NP1 has been removed.
3465 * New features for SVR4
3467 On SVR4 native platforms (such as Solaris), if you attach to a process
3468 without first loading a symbol file, GDB will now attempt to locate and
3469 load symbols from the running process's executable file.
3471 * Many C++ enhancements
3473 C++ support has been greatly improved. Overload resolution now works properly
3474 in almost all cases. RTTI support is on the way.
3476 * Remote targets can connect to a sub-program
3478 A popen(3) style serial-device has been added. This device starts a
3479 sub-process (such as a stand-alone simulator) and then communicates
3480 with that. The sub-program to run is specified using the syntax
3481 ``|<program> <args>'' vis:
3483 (gdb) set remotedebug 1
3484 (gdb) target extended-remote |mn10300-elf-sim program-args
3486 * MIPS 64 remote protocol
3488 A long standing bug in the mips64 remote protocol where by GDB
3489 expected certain 32 bit registers (ex SR) to be transfered as 32
3490 instead of 64 bits has been fixed.
3492 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3493 added to provide backward compatibility with older versions of GDB.
3495 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3497 The command ``set remotebinarydownload'' command has been replaced by
3498 ``set remote X-packet''. Other commands in ``set remote'' family
3499 include ``set remote P-packet''.
3501 * Breakpoint commands accept ranges.
3503 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3504 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3505 ``tracepoint passcount'' also accepts a range of tracepoints.
3507 * ``apropos'' command added.
3509 The ``apropos'' command searches through command names and
3510 documentation strings, printing out matches, making it much easier to
3511 try to find a command that does what you are looking for.
3515 A new machine oriented interface (MI) has been added to GDB. This
3516 interface is designed for debug environments running GDB as a separate
3517 process. This is part of the long term libGDB project. See the
3518 "GDB/MI" chapter of the GDB manual for further information. It can be
3519 enabled by configuring with:
3521 .../configure --enable-gdbmi
3523 *** Changes in GDB-4.18:
3525 * New native configurations
3527 HP-UX 10.20 hppa*-*-hpux10.20
3528 HP-UX 11.x hppa*-*-hpux11.0*
3529 M68K GNU/Linux m68*-*-linux*
3533 Fujitsu FR30 fr30-*-elf*
3534 Intel StrongARM strongarm-*-*
3535 Mitsubishi D30V d30v-*-*
3537 * OBSOLETE configurations
3539 Gould PowerNode, NP1 np1-*-*, pn-*-*
3541 Configurations that have been declared obsolete will be commented out,
3542 but the code will be left in place. If there is no activity to revive
3543 these configurations before the next release of GDB, the sources will
3544 be permanently REMOVED.
3548 As a compatibility experiment, GDB's source files buildsym.h and
3549 buildsym.c have been converted to pure standard C, no longer
3550 containing any K&R compatibility code. We believe that all systems in
3551 use today either come with a standard C compiler, or have a GCC port
3552 available. If this is not true, please report the affected
3553 configuration to bug-gdb@gnu.org immediately. See the README file for
3554 information about getting a standard C compiler if you don't have one
3559 GDB now uses readline 2.2.
3561 * set extension-language
3563 You can now control the mapping between filename extensions and source
3564 languages by using the `set extension-language' command. For instance,
3565 you can ask GDB to treat .c files as C++ by saying
3566 set extension-language .c c++
3567 The command `info extensions' lists all of the recognized extensions
3568 and their associated languages.
3570 * Setting processor type for PowerPC and RS/6000
3572 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3573 you can use the `set processor' command to specify what variant of the
3574 PowerPC family you are debugging. The command
3578 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3579 following PowerPC and RS6000 variants:
3581 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3582 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3584 403GC IBM PowerPC 403GC
3585 505 Motorola PowerPC 505
3586 860 Motorola PowerPC 860 or 850
3587 601 Motorola PowerPC 601
3588 602 Motorola PowerPC 602
3589 603 Motorola/IBM PowerPC 603 or 603e
3590 604 Motorola PowerPC 604 or 604e
3591 750 Motorola/IBM PowerPC 750 or 750
3593 At the moment, this command just tells GDB what to name the
3594 special-purpose processor registers. Since almost all the affected
3595 registers are inaccessible to user-level programs, this command is
3596 only useful for remote debugging in its present form.
3600 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3601 more extensive support for HP-UX. Added features include shared
3602 library support, kernel threads and hardware watchpoints for 11.00,
3603 support for HP's ANSI C and C++ compilers, and a compatibility mode
3604 for xdb and dbx commands.
3608 HP's donation includes the new concept of catchpoints, which is a
3609 generalization of the old catch command. On HP-UX, it is now possible
3610 to catch exec, fork, and vfork, as well as library loading.
3612 This means that the existing catch command has changed; its first
3613 argument now specifies the type of catch to be set up. See the
3614 output of "help catch" for a list of catchpoint types.
3616 * Debugging across forks
3618 On HP-UX, you can choose which process to debug when a fork() happens
3623 HP has donated a curses-based terminal user interface (TUI). To get
3624 it, build with --enable-tui. Although this can be enabled for any
3625 configuration, at present it only works for native HP debugging.
3627 * GDB remote protocol additions
3629 A new protocol packet 'X' that writes binary data is now available.
3630 Default behavior is to try 'X', then drop back to 'M' if the stub
3631 fails to respond. The settable variable `remotebinarydownload'
3632 allows explicit control over the use of 'X'.
3634 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3635 full 64-bit address. The command
3637 set remoteaddresssize 32
3639 can be used to revert to the old behaviour. For existing remote stubs
3640 the change should not be noticed, as the additional address information
3643 In order to assist in debugging stubs, you may use the maintenance
3644 command `packet' to send any text string to the stub. For instance,
3646 maint packet heythere
3648 sends the packet "$heythere#<checksum>". Note that it is very easy to
3649 disrupt a debugging session by sending the wrong packet at the wrong
3652 The compare-sections command allows you to compare section data on the
3653 target to what is in the executable file without uploading or
3654 downloading, by comparing CRC checksums.
3656 * Tracing can collect general expressions
3658 You may now collect general expressions at tracepoints. This requires
3659 further additions to the target-side stub; see tracepoint.c and
3660 doc/agentexpr.texi for further details.
3662 * mask-address variable for Mips
3664 For Mips targets, you may control the zeroing of the upper 32 bits of
3665 a 64-bit address by entering `set mask-address on'. This is mainly
3666 of interest to users of embedded R4xxx and R5xxx processors.
3668 * Higher serial baud rates
3670 GDB's serial code now allows you to specify baud rates 57600, 115200,
3671 230400, and 460800 baud. (Note that your host system may not be able
3672 to achieve all of these rates.)
3676 The i960 configuration now includes an initial implementation of a
3677 builtin simulator, contributed by Jim Wilson.
3680 *** Changes in GDB-4.17:
3682 * New native configurations
3684 Alpha GNU/Linux alpha*-*-linux*
3685 Unixware 2.x i[3456]86-unixware2*
3686 Irix 6.x mips*-sgi-irix6*
3687 PowerPC GNU/Linux powerpc-*-linux*
3688 PowerPC Solaris powerpcle-*-solaris*
3689 Sparc GNU/Linux sparc-*-linux*
3690 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3694 Argonaut Risc Chip (ARC) arc-*-*
3695 Hitachi H8/300S h8300*-*-*
3696 Matsushita MN10200 w/simulator mn10200-*-*
3697 Matsushita MN10300 w/simulator mn10300-*-*
3698 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3699 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3700 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3701 Mitsubishi D10V w/simulator d10v-*-*
3702 Mitsubishi M32R/D w/simulator m32r-*-elf*
3703 Tsqware Sparclet sparclet-*-*
3704 NEC V850 w/simulator v850-*-*
3706 * New debugging protocols
3708 ARM with RDI protocol arm*-*-*
3709 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3710 DDB and LSI variants of PMON protocol mips*-*-*
3711 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3712 PowerPC with SDS protocol powerpc{,le}-*-eabi
3713 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3717 All configurations can now understand and use the DWARF 2 debugging
3718 format. The choice is automatic, if the symbol file contains DWARF 2
3723 GDB now includes basic Java language support. This support is
3724 only useful with Java compilers that produce native machine code.
3726 * solib-absolute-prefix and solib-search-path
3728 For SunOS and SVR4 shared libraries, you may now set the prefix for
3729 loading absolute shared library symbol files, and the search path for
3730 locating non-absolute shared library symbol files.
3732 * Live range splitting
3734 GDB can now effectively debug code for which GCC has performed live
3735 range splitting as part of its optimization. See gdb/doc/LRS for
3736 more details on the expected format of the stabs information.
3740 GDB's support for the GNU Hurd, including thread debugging, has been
3741 updated to work with current versions of the Hurd.
3745 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3746 instruction set. ARM GDB automatically detects when Thumb
3747 instructions are in use, and adjusts disassembly and backtracing
3752 GDB's MIPS target configurations now handle the MIP16 16-bit
3757 GDB now includes support for overlays; if an executable has been
3758 linked such that multiple sections are based at the same address, GDB
3759 will decide which section to use for symbolic info. You can choose to
3760 control the decision manually, using overlay commands, or implement
3761 additional target-side support and use "overlay load-target" to bring
3762 in the overlay mapping. Do "help overlay" for more detail.
3766 The command "info symbol <address>" displays information about
3767 the symbol at the specified address.
3771 The standard remote protocol now includes an extension that allows
3772 asynchronous collection and display of trace data. This requires
3773 extensive support in the target-side debugging stub. Tracing mode
3774 includes a new interaction mode in GDB and new commands: see the
3775 file tracepoint.c for more details.
3779 Configurations for embedded MIPS now include a simulator contributed
3780 by Cygnus Solutions. The simulator supports the instruction sets
3781 of most MIPS variants.
3785 Sparc configurations may now include the ERC32 simulator contributed
3786 by the European Space Agency. The simulator is not built into
3787 Sparc targets by default; configure with --enable-sim to include it.
3791 For target configurations that may include multiple variants of a
3792 basic architecture (such as MIPS and SH), you may now set the
3793 architecture explicitly. "set arch" sets, "info arch" lists
3794 the possible architectures.
3796 *** Changes in GDB-4.16:
3798 * New native configurations
3800 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3801 M68K NetBSD m68k-*-netbsd*
3802 PowerPC AIX 4.x powerpc-*-aix*
3803 PowerPC MacOS powerpc-*-macos*
3804 PowerPC Windows NT powerpcle-*-cygwin32
3805 RS/6000 AIX 4.x rs6000-*-aix4*
3809 ARM with RDP protocol arm-*-*
3810 I960 with MON960 i960-*-coff
3811 MIPS VxWorks mips*-*-vxworks*
3812 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3813 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3815 Matra Sparclet sparclet-*-*
3819 The powerpc-eabi configuration now includes the PSIM simulator,
3820 contributed by Andrew Cagney, with assistance from Mike Meissner.
3821 PSIM is a very elaborate model of the PowerPC, including not only
3822 basic instruction set execution, but also details of execution unit
3823 performance and I/O hardware. See sim/ppc/README for more details.
3827 GDB now works with Solaris 2.5.
3829 * Windows 95/NT native
3831 GDB will now work as a native debugger on Windows 95 and Windows NT.
3832 To build it from source, you must use the "gnu-win32" environment,
3833 which uses a DLL to emulate enough of Unix to run the GNU tools.
3834 Further information, binaries, and sources are available at
3835 ftp.cygnus.com, under pub/gnu-win32.
3837 * dont-repeat command
3839 If a user-defined command includes the command `dont-repeat', then the
3840 command will not be repeated if the user just types return. This is
3841 useful if the command is time-consuming to run, so that accidental
3842 extra keystrokes don't run the same command many times.
3844 * Send break instead of ^C
3846 The standard remote protocol now includes an option to send a break
3847 rather than a ^C to the target in order to interrupt it. By default,
3848 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3850 * Remote protocol timeout
3852 The standard remote protocol includes a new variable `remotetimeout'
3853 that allows you to set the number of seconds before GDB gives up trying
3854 to read from the target. The default value is 2.
3856 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3858 By default GDB will automatically keep track of objects as they are
3859 loaded and unloaded by the dynamic linker. By using the command `set
3860 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3861 when shared library events occur, thus allowing you to set breakpoints
3862 in shared libraries which are explicitly loaded by the inferior.
3864 Note this feature does not work on hpux8. On hpux9 you must link
3865 /usr/lib/end.o into your program. This feature should work
3866 automatically on hpux10.
3868 * Irix 5.x hardware watchpoint support
3870 Irix 5 configurations now support the use of hardware watchpoints.
3872 * Mips protocol "SYN garbage limit"
3874 When debugging a Mips target using the `target mips' protocol, you
3875 may set the number of characters that GDB will ignore by setting
3876 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3877 every character. The default value is 1050.
3879 * Recording and replaying remote debug sessions
3881 If you set `remotelogfile' to the name of a file, gdb will write to it
3882 a recording of a remote debug session. This recording may then be
3883 replayed back to gdb using "gdbreplay". See gdbserver/README for
3884 details. This is useful when you have a problem with GDB while doing
3885 remote debugging; you can make a recording of the session and send it
3886 to someone else, who can then recreate the problem.
3888 * Speedups for remote debugging
3890 GDB includes speedups for downloading and stepping MIPS systems using
3891 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3892 and more efficient S-record downloading.
3894 * Memory use reductions and statistics collection
3896 GDB now uses less memory and reports statistics about memory usage.
3897 Try the `maint print statistics' command, for example.
3899 *** Changes in GDB-4.15:
3901 * Psymtabs for XCOFF
3903 The symbol reader for AIX GDB now uses partial symbol tables. This
3904 can greatly improve startup time, especially for large executables.
3906 * Remote targets use caching
3908 Remote targets now use a data cache to speed up communication with the
3909 remote side. The data cache could lead to incorrect results because
3910 it doesn't know about volatile variables, thus making it impossible to
3911 debug targets which use memory mapped I/O devices. `set remotecache
3912 off' turns the the data cache off.
3914 * Remote targets may have threads
3916 The standard remote protocol now includes support for multiple threads
3917 in the target system, using new protocol commands 'H' and 'T'. See
3918 gdb/remote.c for details.
3922 If GDB is configured with `--enable-netrom', then it will include
3923 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3924 acts as though it is a bank of ROM on the target board, but you can
3925 write into it over the network. GDB's support consists only of
3926 support for fast loading into the emulated ROM; to debug, you must use
3927 another protocol, such as standard remote protocol. The usual
3928 sequence is something like
3930 target nrom <netrom-hostname>
3932 target remote <netrom-hostname>:1235
3936 GDB now includes support for the Apple Macintosh, as a host only. It
3937 may be run as either an MPW tool or as a standalone application, and
3938 it can debug through the serial port. All the usual GDB commands are
3939 available, but to the target command, you must supply "serial" as the
3940 device type instead of "/dev/ttyXX". See mpw-README in the main
3941 directory for more information on how to build. The MPW configuration
3942 scripts */mpw-config.in support only a few targets, and only the
3943 mips-idt-ecoff target has been tested.
3947 GDB configuration now uses autoconf. This is not user-visible,
3948 but does simplify configuration and building.
3952 GDB now supports hpux10.
3954 *** Changes in GDB-4.14:
3956 * New native configurations
3958 x86 FreeBSD i[345]86-*-freebsd
3959 x86 NetBSD i[345]86-*-netbsd
3960 NS32k NetBSD ns32k-*-netbsd
3961 Sparc NetBSD sparc-*-netbsd
3965 A29K VxWorks a29k-*-vxworks
3966 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3967 CPU32 EST-300 emulator m68*-*-est*
3968 PowerPC ELF powerpc-*-elf
3971 * Alpha OSF/1 support for procfs
3973 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3974 possible to attach to running processes. As the mounting of the /proc
3975 filesystem is optional on the Alpha, GDB automatically determines
3976 the availability of /proc during startup. This can lead to problems
3977 if /proc is unmounted after GDB has been started.
3979 * Arguments to user-defined commands
3981 User commands may accept up to 10 arguments separated by whitespace.
3982 Arguments are accessed within the user command via $arg0..$arg9. A
3985 print $arg0 + $arg1 + $arg2
3987 To execute the command use:
3990 Defines the command "adder" which prints the sum of its three arguments.
3991 Note the arguments are text substitutions, so they may reference variables,
3992 use complex expressions, or even perform inferior function calls.
3994 * New `if' and `while' commands
3996 This makes it possible to write more sophisticated user-defined
3997 commands. Both commands take a single argument, which is the
3998 expression to evaluate, and must be followed by the commands to
3999 execute, one per line, if the expression is nonzero, the list being
4000 terminated by the word `end'. The `if' command list may include an
4001 `else' word, which causes the following commands to be executed only
4002 if the expression is zero.
4004 * Fortran source language mode
4006 GDB now includes partial support for Fortran 77. It will recognize
4007 Fortran programs and can evaluate a subset of Fortran expressions, but
4008 variables and functions may not be handled correctly. GDB will work
4009 with G77, but does not yet know much about symbols emitted by other
4012 * Better HPUX support
4014 Most debugging facilities now work on dynamic executables for HPPAs
4015 running hpux9 or later. You can attach to running dynamically linked
4016 processes, but by default the dynamic libraries will be read-only, so
4017 for instance you won't be able to put breakpoints in them. To change
4018 that behavior do the following before running the program:
4024 This will cause the libraries to be mapped private and read-write.
4025 To revert to the normal behavior, do this:
4031 You cannot set breakpoints or examine data in the library until after
4032 the library is loaded if the function/data symbols do not have
4035 GDB can now also read debug symbols produced by the HP C compiler on
4036 HPPAs (sorry, no C++, Fortran or 68k support).
4038 * Target byte order now dynamically selectable
4040 You can choose which byte order to use with a target system, via the
4041 commands "set endian big" and "set endian little", and you can see the
4042 current setting by using "show endian". You can also give the command
4043 "set endian auto", in which case GDB will use the byte order
4044 associated with the executable. Currently, only embedded MIPS
4045 configurations support dynamic selection of target byte order.
4047 * New DOS host serial code
4049 This version uses DPMI interrupts to handle buffered I/O, so you
4050 no longer need to run asynctsr when debugging boards connected to
4053 *** Changes in GDB-4.13:
4055 * New "complete" command
4057 This lists all the possible completions for the rest of the line, if it
4058 were to be given as a command itself. This is intended for use by emacs.
4060 * Trailing space optional in prompt
4062 "set prompt" no longer adds a space for you after the prompt you set. This
4063 allows you to set a prompt which ends in a space or one that does not.
4065 * Breakpoint hit counts
4067 "info break" now displays a count of the number of times the breakpoint
4068 has been hit. This is especially useful in conjunction with "ignore"; you
4069 can ignore a large number of breakpoint hits, look at the breakpoint info
4070 to see how many times the breakpoint was hit, then run again, ignoring one
4071 less than that number, and this will get you quickly to the last hit of
4074 * Ability to stop printing at NULL character
4076 "set print null-stop" will cause GDB to stop printing the characters of
4077 an array when the first NULL is encountered. This is useful when large
4078 arrays actually contain only short strings.
4080 * Shared library breakpoints
4082 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4083 breakpoints in shared libraries before the executable is run.
4085 * Hardware watchpoints
4087 There is a new hardware breakpoint for the watch command for sparclite
4088 targets. See gdb/sparclite/hw_breakpoint.note.
4090 Hardware watchpoints are also now supported under GNU/Linux.
4094 Annotations have been added. These are for use with graphical interfaces,
4095 and are still experimental. Currently only gdba.el uses these.
4097 * Improved Irix 5 support
4099 GDB now works properly with Irix 5.2.
4101 * Improved HPPA support
4103 GDB now works properly with the latest GCC and GAS.
4105 * New native configurations
4107 Sequent PTX4 i[34]86-sequent-ptx4
4108 HPPA running OSF/1 hppa*-*-osf*
4109 Atari TT running SVR4 m68*-*-sysv4*
4110 RS/6000 LynxOS rs6000-*-lynxos*
4114 OS/9000 i[34]86-*-os9k
4115 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4118 * Hitachi SH7000 and E7000-PC ICE support
4120 There is now support for communicating with the Hitachi E7000-PC ICE.
4121 This is available automatically when GDB is configured for the SH.
4125 As usual, a variety of small fixes and improvements, both generic
4126 and configuration-specific. See the ChangeLog for more detail.
4128 *** Changes in GDB-4.12:
4130 * Irix 5 is now supported
4134 GDB-4.12 on the HPPA has a number of changes which make it unable
4135 to debug the output from the currently released versions of GCC and
4136 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4137 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4138 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4141 *** Changes in GDB-4.11:
4143 * User visible changes:
4147 The "set remotedebug" option is now consistent between the mips remote
4148 target, remote targets using the gdb-specific protocol, UDI (AMD's
4149 debug protocol for the 29k) and the 88k bug monitor. It is now an
4150 integer specifying a debug level (normally 0 or 1, but 2 means more
4151 debugging info for the mips target).
4153 * DEC Alpha native support
4155 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4156 debug info, but GDB works fairly well with the DEC compiler and should
4157 work with a future GCC release. See the README file for a few
4158 Alpha-specific notes.
4160 * Preliminary thread implementation
4162 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4164 * LynxOS native and target support for 386
4166 This release has been hosted on LynxOS 2.2, and also can be configured
4167 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4170 * Improvements in C++ mangling/demangling.
4172 This release has much better g++ debugging, specifically in name
4173 mangling/demangling, virtual function calls, print virtual table,
4174 call methods, ...etc.
4176 *** Changes in GDB-4.10:
4178 * User visible changes:
4180 Remote debugging using the GDB-specific (`target remote') protocol now
4181 supports the `load' command. This is only useful if you have some
4182 other way of getting the stub to the target system, and you can put it
4183 somewhere in memory where it won't get clobbered by the download.
4185 Filename completion now works.
4187 When run under emacs mode, the "info line" command now causes the
4188 arrow to point to the line specified. Also, "info line" prints
4189 addresses in symbolic form (as well as hex).
4191 All vxworks based targets now support a user settable option, called
4192 vxworks-timeout. This option represents the number of seconds gdb
4193 should wait for responses to rpc's. You might want to use this if
4194 your vxworks target is, perhaps, a slow software simulator or happens
4195 to be on the far side of a thin network line.
4199 This release contains support for using a DEC alpha as a GDB host for
4200 cross debugging. Native alpha debugging is not supported yet.
4203 *** Changes in GDB-4.9:
4207 This is the first GDB release which is accompanied by a matching testsuite.
4208 The testsuite requires installation of dejagnu, which should be available
4209 via ftp from most sites that carry GNU software.
4213 'Cfront' style demangling has had its name changed to 'ARM' style, to
4214 emphasize that it was written from the specifications in the C++ Annotated
4215 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4216 disclaimers, it still generated too much confusion with users attempting to
4217 use gdb with AT&T cfront.
4221 GDB now uses a standard remote interface to a simulator library.
4222 So far, the library contains simulators for the Zilog Z8001/2, the
4223 Hitachi H8/300, H8/500 and Super-H.
4225 * New targets supported
4227 H8/300 simulator h8300-hitachi-hms or h8300hms
4228 H8/500 simulator h8500-hitachi-hms or h8500hms
4229 SH simulator sh-hitachi-hms or sh
4230 Z8000 simulator z8k-zilog-none or z8ksim
4231 IDT MIPS board over serial line mips-idt-ecoff
4233 Cross-debugging to GO32 targets is supported. It requires a custom
4234 version of the i386-stub.c module which is integrated with the
4235 GO32 memory extender.
4237 * New remote protocols
4239 MIPS remote debugging protocol.
4241 * New source languages supported
4243 This version includes preliminary support for Chill, a Pascal like language
4244 used by telecommunications companies. Chill support is also being integrated
4245 into the GNU compiler, but we don't know when it will be publically available.
4248 *** Changes in GDB-4.8:
4250 * HP Precision Architecture supported
4252 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4253 version of this support was available as a set of patches from the
4254 University of Utah. GDB does not support debugging of programs
4255 compiled with the HP compiler, because HP will not document their file
4256 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4257 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4259 Many problems in the preliminary version have been fixed.
4261 * Faster and better demangling
4263 We have improved template demangling and fixed numerous bugs in the GNU style
4264 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4265 character types (wchar_t) are now supported. Demangling of each symbol is now
4266 only done once, and is cached when the symbol table for a file is read in.
4267 This results in a small increase in memory usage for C programs, a moderate
4268 increase in memory usage for C++ programs, and a fantastic speedup in
4271 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4272 from the specifications in the Annotated Reference Manual, which AT&T's
4273 compiler does not actually implement.
4275 * G++ multiple inheritance compiler problem
4277 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4278 inheritance lattices was reworked to properly discover ambiguities. We
4279 recently found an example which causes this new algorithm to fail in a
4280 very subtle way, producing bad debug information for those classes.
4281 The file 'gcc.patch' (in this directory) can be applied to gcc to
4282 circumvent the problem. A future GCC release will contain a complete
4285 The previous G++ debug info problem (mentioned below for the gdb-4.7
4286 release) is fixed in gcc version 2.3.2.
4288 * Improved configure script
4290 The `configure' script will now attempt to guess your system type if
4291 you don't supply a host system type. The old scheme of supplying a
4292 host system triplet is preferable over using this. All the magic is
4293 done in the new `config.guess' script. Examine it for details.
4295 We have also brought our configure script much more in line with the FSF's
4296 version. It now supports the --with-xxx options. In particular,
4297 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4298 The resulting GDB will not be able to read arbitrary object file formats --
4299 only the format ``expected'' to be used on the configured target system.
4300 We hope to make this the default in a future release.
4302 * Documentation improvements
4304 There's new internal documentation on how to modify GDB, and how to
4305 produce clean changes to the code. We implore people to read it
4306 before submitting changes.
4308 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4309 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4310 `info' files are also provided. To build `info' files from scratch,
4311 you will need the latest `makeinfo' release, which will be available in
4312 a future texinfo-X.Y release.
4314 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4315 We're not sure exactly which versions have this problem, but it has
4316 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4317 or better. If that isn't possible, there is a patch in
4318 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4319 around this problem.
4323 GDB now supports array constants that can be used in expressions typed in by
4324 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4325 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4328 The new directory `gdb/sparclite' contains a program that demonstrates
4329 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4331 * New native hosts supported
4333 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4334 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4336 * New targets supported
4338 AMD 29k family via UDI a29k-amd-udi or udi29k
4340 * New file formats supported
4342 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4343 HPUX core files, and SCO 3.2v2 core files.
4347 Attaching to processes now works again; thanks for the many bug reports.
4349 We have also stomped on a bunch of core dumps caused by
4350 printf_filtered("%s") problems.
4352 We eliminated a copyright problem on the rpc and ptrace header files
4353 for VxWorks, which was discovered at the last minute during the 4.7
4354 release. You should now be able to build a VxWorks GDB.
4356 You can now interrupt gdb while an attached process is running. This
4357 will cause the attached process to stop, and give control back to GDB.
4359 We fixed problems caused by using too many file descriptors
4360 for reading symbols from object files and libraries. This was
4361 especially a problem for programs that used many (~100) shared
4364 The `step' command now only enters a subroutine if there is line number
4365 information for the subroutine. Otherwise it acts like the `next'
4366 command. Previously, `step' would enter subroutines if there was
4367 any debugging information about the routine. This avoids problems
4368 when using `cc -g1' on MIPS machines.
4370 * Internal improvements
4372 GDB's internal interfaces have been improved to make it easier to support
4373 debugging of multiple languages in the future.
4375 GDB now uses a common structure for symbol information internally.
4376 Minimal symbols (derived from linkage symbols in object files), partial
4377 symbols (from a quick scan of debug information), and full symbols
4378 contain a common subset of information, making it easier to write
4379 shared code that handles any of them.
4381 * New command line options
4383 We now accept --silent as an alias for --quiet.
4387 The memory-mapped-malloc library is now licensed under the GNU Library
4388 General Public License.
4390 *** Changes in GDB-4.7:
4392 * Host/native/target split
4394 GDB has had some major internal surgery to untangle the support for
4395 hosts and remote targets. Now, when you configure GDB for a remote
4396 target, it will no longer load in all of the support for debugging
4397 local programs on the host. When fully completed and tested, this will
4398 ensure that arbitrary host/target combinations are possible.
4400 The primary conceptual shift is to separate the non-portable code in
4401 GDB into three categories. Host specific code is required any time GDB
4402 is compiled on that host, regardless of the target. Target specific
4403 code relates to the peculiarities of the target, but can be compiled on
4404 any host. Native specific code is everything else: it can only be
4405 built when the host and target are the same system. Child process
4406 handling and core file support are two common `native' examples.
4408 GDB's use of /proc for controlling Unix child processes is now cleaner.
4409 It has been split out into a single module under the `target_ops' vector,
4410 plus two native-dependent functions for each system that uses /proc.
4412 * New hosts supported
4414 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4415 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4416 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4418 * New targets supported
4420 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4421 68030 and CPU32 m68030-*-*, m68332-*-*
4423 * New native hosts supported
4425 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4426 (386bsd is not well tested yet)
4427 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4429 * New file formats supported
4431 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4432 supports reading of `a.out.adobe' object files, which are an a.out
4433 format extended with minimal information about multiple sections.
4437 `show copying' is the same as the old `info copying'.
4438 `show warranty' is the same as `info warrantee'.
4439 These were renamed for consistency. The old commands continue to work.
4441 `info handle' is a new alias for `info signals'.
4443 You can now define pre-command hooks, which attach arbitrary command
4444 scripts to any command. The commands in the hook will be executed
4445 prior to the user's command. You can also create a hook which will be
4446 executed whenever the program stops. See gdb.texinfo.
4450 We now deal with Cfront style name mangling, and can even extract type
4451 info from mangled symbols. GDB can automatically figure out which
4452 symbol mangling style your C++ compiler uses.
4454 Calling of methods and virtual functions has been improved as well.
4458 The crash that occured when debugging Sun Ansi-C compiled binaries is
4459 fixed. This was due to mishandling of the extra N_SO stabs output
4462 We also finally got Ultrix 4.2 running in house, and fixed core file
4463 support, with help from a dozen people on the net.
4465 John M. Farrell discovered that the reason that single-stepping was so
4466 slow on all of the Mips based platforms (primarily SGI and DEC) was
4467 that we were trying to demangle and lookup a symbol used for internal
4468 purposes on every instruction that was being stepped through. Changing
4469 the name of that symbol so that it couldn't be mistaken for a C++
4470 mangled symbol sped things up a great deal.
4472 Rich Pixley sped up symbol lookups in general by getting much smarter
4473 about when C++ symbol mangling is necessary. This should make symbol
4474 completion (TAB on the command line) much faster. It's not as fast as
4475 we'd like, but it's significantly faster than gdb-4.6.
4479 A new user controllable variable 'call_scratch_address' can
4480 specify the location of a scratch area to be used when GDB
4481 calls a function in the target. This is necessary because the
4482 usual method of putting the scratch area on the stack does not work
4483 in systems that have separate instruction and data spaces.
4485 We integrated changes to support the 29k UDI (Universal Debugger
4486 Interface), but discovered at the last minute that we didn't have all
4487 of the appropriate copyright paperwork. We are working with AMD to
4488 resolve this, and hope to have it available soon.
4492 We have sped up the remote serial line protocol, especially for targets
4493 with lots of registers. It now supports a new `expedited status' ('T')
4494 message which can be used in place of the existing 'S' status message.
4495 This allows the remote stub to send only the registers that GDB
4496 needs to make a quick decision about single-stepping or conditional
4497 breakpoints, eliminating the need to fetch the entire register set for
4498 each instruction being stepped through.
4500 The GDB remote serial protocol now implements a write-through cache for
4501 registers, only re-reading the registers if the target has run.
4503 There is also a new remote serial stub for SPARC processors. You can
4504 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4505 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4506 processor with a serial port.
4510 Configure.in files have become much easier to read and modify. A new
4511 `table driven' format makes it more obvious what configurations are
4512 supported, and what files each one uses.
4516 There is a new opcodes library which will eventually contain all of the
4517 disassembly routines and opcode tables. At present, it only contains
4518 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4519 disassembler (binutils/objdump) to share these routines.
4521 The libiberty library is now copylefted under the GNU Library General
4522 Public License. This allows more liberal use, and was done so libg++
4523 can use it. This makes no difference to GDB, since the Library License
4524 grants all the rights from the General Public License.
4528 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4529 reference to the stabs symbol info used by the debugger. It is (as far
4530 as we know) the only published document on this fascinating topic. We
4531 encourage you to read it, compare it to the stabs information on your
4532 system, and send improvements on the document in general (to
4533 bug-gdb@prep.ai.mit.edu).
4535 And, of course, many bugs have been fixed.
4538 *** Changes in GDB-4.6:
4540 * Better support for C++ function names
4542 GDB now accepts as input the "demangled form" of C++ overloaded function
4543 names and member function names, and can do command completion on such names
4544 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4545 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4546 Make use of command completion, it is your friend.
4548 GDB also now accepts a variety of C++ mangled symbol formats. They are
4549 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4550 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4551 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4552 for the list of formats.
4554 * G++ symbol mangling problem
4556 Recent versions of gcc have a bug in how they emit debugging information for
4557 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4558 directory) can be applied to gcc to fix the problem. Alternatively, if you
4559 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4560 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4561 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4564 * New 'maintenance' command
4566 All of the commands related to hacking GDB internals have been moved out of
4567 the main command set, and now live behind the 'maintenance' command. This
4568 can also be abbreviated as 'mt'. The following changes were made:
4570 dump-me -> maintenance dump-me
4571 info all-breakpoints -> maintenance info breakpoints
4572 printmsyms -> maintenance print msyms
4573 printobjfiles -> maintenance print objfiles
4574 printpsyms -> maintenance print psymbols
4575 printsyms -> maintenance print symbols
4577 The following commands are new:
4579 maintenance demangle Call internal GDB demangler routine to
4580 demangle a C++ link name and prints the result.
4581 maintenance print type Print a type chain for a given symbol
4583 * Change to .gdbinit file processing
4585 We now read the $HOME/.gdbinit file before processing the argv arguments
4586 (e.g. reading symbol files or core files). This allows global parameters to
4587 be set, which will apply during the symbol reading. The ./.gdbinit is still
4588 read after argv processing.
4590 * New hosts supported
4592 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4594 GNU/Linux support i386-unknown-linux or linux
4596 We are also including code to support the HP/PA running BSD and HPUX. This
4597 is almost guaranteed not to work, as we didn't have time to test or build it
4598 for this release. We are including it so that the more adventurous (or
4599 masochistic) of you can play with it. We also had major problems with the
4600 fact that the compiler that we got from HP doesn't support the -g option.
4603 * New targets supported
4605 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4607 * More smarts about finding #include files
4609 GDB now remembers the compilation directory for all include files, and for
4610 all files from which C is generated (like yacc and lex sources). This
4611 greatly improves GDB's ability to find yacc/lex sources, and include files,
4612 especially if you are debugging your program from a directory different from
4613 the one that contains your sources.
4615 We also fixed a bug which caused difficulty with listing and setting
4616 breakpoints in include files which contain C code. (In the past, you had to
4617 try twice in order to list an include file that you hadn't looked at before.)
4619 * Interesting infernals change
4621 GDB now deals with arbitrary numbers of sections, where the symbols for each
4622 section must be relocated relative to that section's landing place in the
4623 target's address space. This work was needed to support ELF with embedded
4624 stabs used by Solaris-2.0.
4626 * Bug fixes (of course!)
4628 There have been loads of fixes for the following things:
4629 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4630 i960, stabs, DOS(GO32), procfs, etc...
4632 See the ChangeLog for details.
4634 *** Changes in GDB-4.5:
4636 * New machines supported (host and target)
4638 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4640 SGI Irix-4.x mips-sgi-irix4 or iris4
4642 * New malloc package
4644 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4645 Mmalloc is capable of handling mutiple heaps of memory. It is also
4646 capable of saving a heap to a file, and then mapping it back in later.
4647 This can be used to greatly speedup the startup of GDB by using a
4648 pre-parsed symbol table which lives in a mmalloc managed heap. For
4649 more details, please read mmalloc/mmalloc.texi.
4653 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4654 'help info proc' for details.
4656 * MIPS ecoff symbol table format
4658 The code that reads MIPS symbol table format is now supported on all hosts.
4659 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4662 * File name changes for MS-DOS
4664 Many files in the config directories have been renamed to make it easier to
4665 support GDB on MS-DOSe systems (which have very restrictive file name
4666 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4667 environment) is close to working but has some remaining problems. Note
4668 that debugging of DOS programs is not supported, due to limitations
4669 in the ``operating system'', but it can be used to host cross-debugging.
4671 * Cross byte order fixes
4673 Many fixes have been made to support cross debugging of Sparc and MIPS
4674 targets from hosts whose byte order differs.
4676 * New -mapped and -readnow options
4678 If memory-mapped files are available on your system through the 'mmap'
4679 system call, you can use the -mapped option on the `file' or
4680 `symbol-file' commands to cause GDB to write the symbols from your
4681 program into a reusable file. If the program you are debugging is
4682 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4683 Future GDB debugging sessions will notice the presence of this file,
4684 and will quickly map in symbol information from it, rather than reading
4685 the symbol table from the executable program. Using the '-mapped'
4686 option in a GDB `file' or `symbol-file' command has the same effect as
4687 starting GDB with the '-mapped' command-line option.
4689 You can cause GDB to read the entire symbol table immediately by using
4690 the '-readnow' option with any of the commands that load symbol table
4691 information (or on the GDB command line). This makes the command
4692 slower, but makes future operations faster.
4694 The -mapped and -readnow options are typically combined in order to
4695 build a `fred.syms' file that contains complete symbol information.
4696 A simple GDB invocation to do nothing but build a `.syms' file for future
4699 gdb -batch -nx -mapped -readnow programname
4701 The `.syms' file is specific to the host machine on which GDB is run.
4702 It holds an exact image of GDB's internal symbol table. It cannot be
4703 shared across multiple host platforms.
4705 * longjmp() handling
4707 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4708 siglongjmp() without losing control. This feature has not yet been ported to
4709 all systems. It currently works on many 386 platforms, all MIPS-based
4710 platforms (SGI, DECstation, etc), and Sun3/4.
4714 Preliminary work has been put in to support the new Solaris OS from Sun. At
4715 this time, it can control and debug processes, but it is not capable of
4720 As always, many many bug fixes. The major areas were with g++, and mipsread.
4721 People using the MIPS-based platforms should experience fewer mysterious
4722 crashes and trashed symbol tables.
4724 *** Changes in GDB-4.4:
4726 * New machines supported (host and target)
4728 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4730 BSD Reno on Vax vax-dec-bsd
4731 Ultrix on Vax vax-dec-ultrix
4733 * New machines supported (target)
4735 AMD 29000 embedded, using EBMON a29k-none-none
4739 GDB continues to improve its handling of C++. `References' work better.
4740 The demangler has also been improved, and now deals with symbols mangled as
4741 per the Annotated C++ Reference Guide.
4743 GDB also now handles `stabs' symbol information embedded in MIPS
4744 `ecoff' symbol tables. Since the ecoff format was not easily
4745 extensible to handle new languages such as C++, this appeared to be a
4746 good way to put C++ debugging info into MIPS binaries. This option
4747 will be supported in the GNU C compiler, version 2, when it is
4750 * New features for SVR4
4752 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4753 shared libraries. Debugging dynamically linked programs should present
4754 only minor differences from debugging statically linked programs.
4756 The `info proc' command will print out information about any process
4757 on an SVR4 system (including the one you are debugging). At the moment,
4758 it prints the address mappings of the process.
4760 If you bring up GDB on another SVR4 system, please send mail to
4761 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4763 * Better dynamic linking support in SunOS
4765 Reading symbols from shared libraries which contain debugging symbols
4766 now works properly. However, there remain issues such as automatic
4767 skipping of `transfer vector' code during function calls, which
4768 make it harder to debug code in a shared library, than to debug the
4769 same code linked statically.
4773 GDB is now using the latest `getopt' routines from the FSF. This
4774 version accepts the -- prefix for options with long names. GDB will
4775 continue to accept the old forms (-option and +option) as well.
4776 Various single letter abbreviations for options have been explicity
4777 added to the option table so that they won't get overshadowed in the
4778 future by other options that begin with the same letter.
4782 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4783 Many assorted bugs have been handled. Many more remain to be handled.
4784 See the various ChangeLog files (primarily in gdb and bfd) for details.
4787 *** Changes in GDB-4.3:
4789 * New machines supported (host and target)
4791 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4792 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4793 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4795 * Almost SCO Unix support
4797 We had hoped to support:
4798 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4799 (except for core file support), but we discovered very late in the release
4800 that it has problems with process groups that render gdb unusable. Sorry
4801 about that. I encourage people to fix it and post the fixes.
4803 * Preliminary ELF and DWARF support
4805 GDB can read ELF object files on System V Release 4, and can handle
4806 debugging records for C, in DWARF format, in ELF files. This support
4807 is preliminary. If you bring up GDB on another SVR4 system, please
4808 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4813 GDB now uses the latest `readline' library. One user-visible change
4814 is that two tabs will list possible command completions, which previously
4815 required typing M-? (meta-question mark, or ESC ?).
4819 The `stepi' bug that many of you noticed has been squashed.
4820 Many bugs in C++ have been handled. Many more remain to be handled.
4821 See the various ChangeLog files (primarily in gdb and bfd) for details.
4823 * State of the MIPS world (in case you wondered):
4825 GDB can understand the symbol tables emitted by the compilers
4826 supplied by most vendors of MIPS-based machines, including DEC. These
4827 symbol tables are in a format that essentially nobody else uses.
4829 Some versions of gcc come with an assembler post-processor called
4830 mips-tfile. This program is required if you want to do source-level
4831 debugging of gcc-compiled programs. I believe FSF does not ship
4832 mips-tfile with gcc version 1, but it will eventually come with gcc
4835 Debugging of g++ output remains a problem. g++ version 1.xx does not
4836 really support it at all. (If you're lucky, you should be able to get
4837 line numbers and stack traces to work, but no parameters or local
4838 variables.) With some work it should be possible to improve the
4841 When gcc version 2 is released, you will have somewhat better luck.
4842 However, even then you will get confusing results for inheritance and
4845 We will eventually provide full debugging of g++ output on
4846 DECstations. This will probably involve some kind of stabs-in-ecoff
4847 encapulation, but the details have not been worked out yet.
4850 *** Changes in GDB-4.2:
4852 * Improved configuration
4854 Only one copy of `configure' exists now, and it is not self-modifying.
4855 Porting BFD is simpler.
4859 The `step' and `next' commands now only stop at the first instruction
4860 of a source line. This prevents the multiple stops that used to occur
4861 in switch statements, for-loops, etc. `Step' continues to stop if a
4862 function that has debugging information is called within the line.
4866 Lots of small bugs fixed. More remain.
4868 * New host supported (not target)
4870 Intel 386 PC clone running Mach i386-none-mach
4873 *** Changes in GDB-4.1:
4875 * Multiple source language support
4877 GDB now has internal scaffolding to handle several source languages.
4878 It determines the type of each source file from its filename extension,
4879 and will switch expression parsing and number formatting to match the
4880 language of the function in the currently selected stack frame.
4881 You can also specifically set the language to be used, with
4882 `set language c' or `set language modula-2'.
4886 GDB now has preliminary support for the GNU Modula-2 compiler,
4887 currently under development at the State University of New York at
4888 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4889 continue through the fall of 1991 and into 1992.
4891 Other Modula-2 compilers are currently not supported, and attempting to
4892 debug programs compiled with them will likely result in an error as the
4893 symbol table is read. Feel free to work on it, though!
4895 There are hooks in GDB for strict type checking and range checking,
4896 in the `Modula-2 philosophy', but they do not currently work.
4900 GDB can now write to executable and core files (e.g. patch
4901 a variable's value). You must turn this switch on, specify
4902 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4903 by assigning a new value to a variable. Modifications take
4906 * Automatic SunOS shared library reading
4908 When you run your program, GDB automatically determines where its
4909 shared libraries (if any) have been loaded, and reads their symbols.
4910 The `share' command is no longer needed. This also works when
4911 examining core files.
4915 You can specify the number of lines that the `list' command shows.
4918 * New machines supported (host and target)
4920 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4921 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4922 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4924 * New hosts supported (not targets)
4926 IBM RT/PC: romp-ibm-aix or rtpc
4928 * New targets supported (not hosts)
4930 AMD 29000 embedded with COFF a29k-none-coff
4931 AMD 29000 embedded with a.out a29k-none-aout
4932 Ultracomputer remote kernel debug a29k-nyu-kern
4934 * New remote interfaces
4940 *** Changes in GDB-4.0:
4944 Wide output is wrapped at good places to make the output more readable.
4946 Gdb now supports cross-debugging from a host machine of one type to a
4947 target machine of another type. Communication with the target system
4948 is over serial lines. The ``target'' command handles connecting to the
4949 remote system; the ``load'' command will download a program into the
4950 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4951 also supports debugging of realtime processes running under VxWorks,
4952 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4953 stub on the target system.
4955 New CPUs supported include the AMD 29000 and Intel 960.
4957 GDB now reads object files and symbol tables via a ``binary file''
4958 library, which allows a single copy of GDB to debug programs of multiple
4959 object file types such as a.out and coff.
4961 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4962 refcard.dvi and refcard.ps are available to format it).
4965 * Control-Variable user interface simplified
4967 All variables that control the operation of the debugger can be set
4968 by the ``set'' command, and displayed by the ``show'' command.
4970 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4971 ``Show prompt'' produces the response:
4972 Gdb's prompt is new-gdb=>.
4974 What follows are the NEW set commands. The command ``help set'' will
4975 print a complete list of old and new set commands. ``help set FOO''
4976 will give a longer description of the variable FOO. ``show'' will show
4977 all of the variable descriptions and their current settings.
4979 confirm on/off: Enables warning questions for operations that are
4980 hard to recover from, e.g. rerunning the program while
4981 it is already running. Default is ON.
4983 editing on/off: Enables EMACS style command line editing
4984 of input. Previous lines can be recalled with
4985 control-P, the current line can be edited with control-B,
4986 you can search for commands with control-R, etc.
4989 history filename NAME: NAME is where the gdb command history
4990 will be stored. The default is .gdb_history,
4991 or the value of the environment variable
4994 history size N: The size, in commands, of the command history. The
4995 default is 256, or the value of the environment variable
4998 history save on/off: If this value is set to ON, the history file will
4999 be saved after exiting gdb. If set to OFF, the
5000 file will not be saved. The default is OFF.
5002 history expansion on/off: If this value is set to ON, then csh-like
5003 history expansion will be performed on
5004 command line input. The default is OFF.
5006 radix N: Sets the default radix for input and output. It can be set
5007 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5008 in the current radix, so "set radix 10" is always a no-op.
5010 height N: This integer value is the number of lines on a page. Default
5011 is 24, the current `stty rows'' setting, or the ``li#''
5012 setting from the termcap entry matching the environment
5015 width N: This integer value is the number of characters on a line.
5016 Default is 80, the current `stty cols'' setting, or the ``co#''
5017 setting from the termcap entry matching the environment
5020 Note: ``set screensize'' is obsolete. Use ``set height'' and
5021 ``set width'' instead.
5023 print address on/off: Print memory addresses in various command displays,
5024 such as stack traces and structure values. Gdb looks
5025 more ``symbolic'' if you turn this off; it looks more
5026 ``machine level'' with it on. Default is ON.
5028 print array on/off: Prettyprint arrays. New convenient format! Default
5031 print demangle on/off: Print C++ symbols in "source" form if on,
5034 print asm-demangle on/off: Same, for assembler level printouts
5037 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5040 * Support for Epoch Environment.
5042 The epoch environment is a version of Emacs v18 with windowing. One
5043 new command, ``inspect'', is identical to ``print'', except that if you
5044 are running in the epoch environment, the value is printed in its own
5048 * Support for Shared Libraries
5050 GDB can now debug programs and core files that use SunOS shared libraries.
5051 Symbols from a shared library cannot be referenced
5052 before the shared library has been linked with the program (this
5053 happens after you type ``run'' and before the function main() is entered).
5054 At any time after this linking (including when examining core files
5055 from dynamically linked programs), gdb reads the symbols from each
5056 shared library when you type the ``sharedlibrary'' command.
5057 It can be abbreviated ``share''.
5059 sharedlibrary REGEXP: Load shared object library symbols for files
5060 matching a unix regular expression. No argument
5061 indicates to load symbols for all shared libraries.
5063 info sharedlibrary: Status of loaded shared libraries.
5068 A watchpoint stops execution of a program whenever the value of an
5069 expression changes. Checking for this slows down execution
5070 tremendously whenever you are in the scope of the expression, but is
5071 quite useful for catching tough ``bit-spreader'' or pointer misuse
5072 problems. Some machines such as the 386 have hardware for doing this
5073 more quickly, and future versions of gdb will use this hardware.
5075 watch EXP: Set a watchpoint (breakpoint) for an expression.
5077 info watchpoints: Information about your watchpoints.
5079 delete N: Deletes watchpoint number N (same as breakpoints).
5080 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5081 enable N: Re-enables watchpoint number N (same as breakpoints).
5084 * C++ multiple inheritance
5086 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5089 * C++ exception handling
5091 Gdb now supports limited C++ exception handling. Besides the existing
5092 ability to breakpoint on an exception handler, gdb can breakpoint on
5093 the raising of an exception (before the stack is peeled back to the
5096 catch FOO: If there is a FOO exception handler in the dynamic scope,
5097 set a breakpoint to catch exceptions which may be raised there.
5098 Multiple exceptions (``catch foo bar baz'') may be caught.
5100 info catch: Lists all exceptions which may be caught in the
5101 current stack frame.
5104 * Minor command changes
5106 The command ``call func (arg, arg, ...)'' now acts like the print
5107 command, except it does not print or save a value if the function's result
5108 is void. This is similar to dbx usage.
5110 The ``up'' and ``down'' commands now always print the frame they end up
5111 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5112 frames without printing.
5114 * New directory command
5116 'dir' now adds directories to the FRONT of the source search path.
5117 The path starts off empty. Source files that contain debug information
5118 about the directory in which they were compiled can be found even
5119 with an empty path; Sun CC and GCC include this information. If GDB can't
5120 find your source file in the current directory, type "dir .".
5122 * Configuring GDB for compilation
5124 For normal use, type ``./configure host''. See README or gdb.texinfo
5127 GDB now handles cross debugging. If you are remotely debugging between
5128 two different machines, type ``./configure host -target=targ''.
5129 Host is the machine where GDB will run; targ is the machine
5130 where the program that you are debugging will run.