1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.5
6 * New command line options:
8 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
9 other initialization files, unlike -nx which disables all of them.
13 ** Vectors can be created with gdb.Type.vector.
15 ** Python's atexit.register now works in GDB.
17 * New Python-based convenience functions:
19 ** $_memeq(buf1, buf2, length)
20 ** $_streq(str1, str2)
22 ** $_regex(str, regex)
24 * The 'cd' command now defaults to using '~' (the home directory) if not
27 * New configure options
29 --enable-libmcheck/--disable-libmcheck
30 By default, development versions are built with -lmcheck on hosts
31 that support it, in order to help track memory corruption issues.
32 Release versions, on the other hand, are built without -lmcheck
33 by default. The --enable-libmcheck/--disable-libmcheck configure
34 options allow the user to override that default.
36 * New commands (for set/show, see "New options" below)
39 List the BFDs known to GDB.
41 python-interactive [command]
43 Start a Python interactive prompt, or evaluate the optional command
44 and print the result of expressions.
47 "py" is a new alias for "python".
51 ** For the Renesas Super-H architecture, the "regs" command has been removed
52 (has been deprecated in GDB 7.5), and "info all-registers" should be used
57 ** Command parameter changes are now notified using new async record
59 ** Trace frame changes caused by command "tfind" are now notified using
60 new async record "=traceframe-changed".
61 ** The creation and deletion of trace state variables are now notified
62 using new async records "=tsv-created" and "=tsv-deleted".
63 ** The start and stop of process record are now notified using new
64 async record "=record-started" and "=record-stopped".
65 ** Memory changes are now notified using new async record
68 *** Changes in GDB 7.5
70 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
71 for more x32 ABI info.
73 * GDB now supports access to MIPS DSP registers on Linux targets.
75 * GDB now supports debugging microMIPS binaries.
77 * The "info os" command on GNU/Linux can now display information on
78 several new classes of objects managed by the operating system:
79 "info os procgroups" lists process groups
80 "info os files" lists file descriptors
81 "info os sockets" lists internet-domain sockets
82 "info os shm" lists shared-memory regions
83 "info os semaphores" lists semaphores
84 "info os msg" lists message queues
85 "info os modules" lists loaded kernel modules
87 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
88 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
89 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
90 options and inspect the probe arguments using the new $_probe_arg family
91 of convenience variables. You can obtain more information about SystemTap
92 in <http://sourceware.org/systemtap/>.
94 * GDB now supports reversible debugging on ARM, it allows you to
95 debug basic ARM and THUMB instructions, and provides
96 record/replay support.
98 * The option "symbol-reloading" has been deleted as it is no longer used.
102 ** GDB commands implemented in Python can now be put in command class
105 ** The "maint set python print-stack on|off" is now deleted.
107 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
108 apply "flag enum"-style pretty-printing to any enum.
110 ** gdb.lookup_symbol can now work when there is no current frame.
112 ** gdb.Symbol now has a 'line' attribute, holding the line number in
113 the source at which the symbol was defined.
115 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
116 method 'value'. The former indicates whether the symbol needs a
117 frame in order to compute its value, and the latter computes the
120 ** A new method 'referenced_value' on gdb.Value objects which can
121 dereference pointer as well as C++ reference values.
123 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
124 which return the global and static blocks (as gdb.Block objects),
125 of the underlying symbol table, respectively.
127 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
128 object associated with a PC value.
130 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
131 of the address range occupied by code for the current source line.
133 * Go language support.
134 GDB now supports debugging programs written in the Go programming
137 * GDBserver now supports stdio connections.
138 E.g. (gdb) target remote | ssh myhost gdbserver - hello
140 * The binary "gdbtui" can no longer be built or installed.
141 Use "gdb -tui" instead.
143 * GDB will now print "flag" enums specially. A flag enum is one where
144 all the enumerator values have no bits in common when pairwise
145 "and"ed. When printing a value whose type is a flag enum, GDB will
146 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
147 (gdb) print (enum E) 3
150 * The filename part of a linespec will now match trailing components
151 of a source file name. For example, "break gcc/expr.c:1000" will
152 now set a breakpoint in build/gcc/expr.c, but not
155 * The "info proc" and "generate-core-file" commands will now also
156 work on remote targets connected to GDBserver on Linux.
158 * The command "info catch" has been removed. It has been disabled
161 * The "catch exception" and "catch assert" commands now accept
162 a condition at the end of the command, much like the "break"
163 command does. For instance:
165 (gdb) catch exception Constraint_Error if Barrier = True
167 Previously, it was possible to add a condition to such catchpoints,
168 but it had to be done as a second step, after the catchpoint had been
169 created, using the "condition" command.
171 * The "info static-tracepoint-marker" command will now also work on
172 native Linux targets with in-process agent.
174 * GDB can now set breakpoints on inlined functions.
176 * The .gdb_index section has been updated to include symbols for
177 inlined functions. GDB will ignore older .gdb_index sections by
178 default, which could cause symbol files to be loaded more slowly
179 until their .gdb_index sections can be recreated. The new command
180 "set use-deprecated-index-sections on" will cause GDB to use any older
181 .gdb_index sections it finds. This will restore performance, but the
182 ability to set breakpoints on inlined functions will be lost in symbol
183 files with older .gdb_index sections.
185 The .gdb_index section has also been updated to record more information
186 about each symbol. This speeds up the "info variables", "info functions"
187 and "info types" commands when used with programs having the .gdb_index
188 section, as well as speeding up debugging with shared libraries using
189 the .gdb_index section.
191 * Ada support for GDB/MI Variable Objects has been added.
193 * GDB can now support 'breakpoint always-inserted mode' in 'record'
198 ** New command -info-os is the MI equivalent of "info os".
200 ** Output logs ("set logging" and related) now include MI output.
204 ** "set use-deprecated-index-sections on|off"
205 "show use-deprecated-index-sections on|off"
206 Controls the use of deprecated .gdb_index sections.
208 ** "catch load" and "catch unload" can be used to stop when a shared
209 library is loaded or unloaded, respectively.
211 ** "enable count" can be used to auto-disable a breakpoint after
214 ** "info vtbl" can be used to show the virtual method tables for
215 C++ and Java objects.
217 ** "explore" and its sub commands "explore value" and "explore type"
218 can be used to reccursively explore values and types of
219 expressions. These commands are available only if GDB is
220 configured with '--with-python'.
222 ** "info auto-load" shows status of all kinds of auto-loaded files,
223 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
224 sequences of commands files, "info auto-load python-scripts"
225 shows status of auto-loading Python script files,
226 "info auto-load local-gdbinit" shows status of loading init file
227 (.gdbinit) from current directory and "info auto-load libthread-db" shows
228 status of inferior specific thread debugging shared library loading.
230 ** "info auto-load-scripts", "set auto-load-scripts on|off"
231 and "show auto-load-scripts" commands have been deprecated, use their
232 "info auto-load python-scripts", "set auto-load python-scripts on|off"
233 and "show auto-load python-scripts" counterparts instead.
235 ** "dprintf location,format,args..." creates a dynamic printf, which
236 is basically a breakpoint that does a printf and immediately
237 resumes your program's execution, so it is like a printf that you
238 can insert dynamically at runtime instead of at compiletime.
240 ** "set print symbol"
242 Controls whether GDB attempts to display the symbol, if any,
243 corresponding to addresses it prints. This defaults to "on", but
244 you can set it to "off" to restore GDB's previous behavior.
246 * Deprecated commands
248 ** For the Renesas Super-H architecture, the "regs" command has been
249 deprecated, and "info all-registers" should be used instead.
253 Renesas RL78 rl78-*-elf
254 HP OpenVMS ia64 ia64-hp-openvms*
256 * GDBserver supports evaluation of breakpoint conditions. When
257 support is advertised by GDBserver, GDB may be told to send the
258 breakpoint conditions in bytecode form to GDBserver. GDBserver
259 will only report the breakpoint trigger to GDB when its condition
265 show mips compression
266 Select the compressed ISA encoding used in functions that have no symbol
267 information available. The encoding can be set to either of:
270 and is updated automatically from ELF file flags if available.
272 set breakpoint condition-evaluation
273 show breakpoint condition-evaluation
274 Control whether breakpoint conditions are evaluated by GDB ("host") or by
275 GDBserver ("target"). Default option "auto" chooses the most efficient
277 This option can improve debugger efficiency depending on the speed of the
281 Disable auto-loading globally.
284 Show auto-loading setting of all kinds of auto-loaded files.
286 set auto-load gdb-scripts on|off
287 show auto-load gdb-scripts
288 Control auto-loading of GDB canned sequences of commands files.
290 set auto-load python-scripts on|off
291 show auto-load python-scripts
292 Control auto-loading of Python script files.
294 set auto-load local-gdbinit on|off
295 show auto-load local-gdbinit
296 Control loading of init file (.gdbinit) from current directory.
298 set auto-load libthread-db on|off
299 show auto-load libthread-db
300 Control auto-loading of inferior specific thread debugging shared library.
302 set auto-load scripts-directory <dir1>[:<dir2>...]
303 show auto-load scripts-directory
304 Set a list of directories from which to load auto-loaded scripts.
305 Automatically loaded Python scripts and GDB scripts are located in one
306 of the directories listed by this option.
307 The delimiter (':' above) may differ according to the host platform.
309 set auto-load safe-path <dir1>[:<dir2>...]
310 show auto-load safe-path
311 Set a list of directories from which it is safe to auto-load files.
312 The delimiter (':' above) may differ according to the host platform.
314 set debug auto-load on|off
316 Control display of debugging info for auto-loading the files above.
318 set dprintf-style gdb|call|agent
320 Control the way in which a dynamic printf is performed; "gdb"
321 requests a GDB printf command, while "call" causes dprintf to call a
322 function in the inferior. "agent" requests that the target agent
323 (such as GDBserver) do the printing.
325 set dprintf-function <expr>
326 show dprintf-function
327 set dprintf-channel <expr>
329 Set the function and optional first argument to the call when using
330 the "call" style of dynamic printf.
332 set disconnected-dprintf on|off
333 show disconnected-dprintf
334 Control whether agent-style dynamic printfs continue to be in effect
335 after GDB disconnects.
337 * New configure options
340 Configure default value for the 'set auto-load scripts-directory'
341 setting above. It defaults to '$debugdir:$datadir/auto-load',
342 $debugdir representing global debugging info directories (available
343 via 'show debug-file-directory') and $datadir representing GDB's data
344 directory (available via 'show data-directory').
346 --with-auto-load-safe-path
347 Configure default value for the 'set auto-load safe-path' setting
348 above. It defaults to the --with-auto-load-dir setting.
350 --without-auto-load-safe-path
351 Set 'set auto-load safe-path' to '/', effectively disabling this
356 z0/z1 conditional breakpoints extension
358 The z0/z1 breakpoint insertion packets have been extended to carry
359 a list of conditional expressions over to the remote stub depending on the
360 condition evaluation mode. The use of this extension can be controlled
361 via the "set remote conditional-breakpoints-packet" command.
365 Specify the signals which the remote stub may pass to the debugged
366 program without GDB involvement.
368 * New command line options
370 --init-command=FILE, -ix Like --command, -x but execute it
371 before loading inferior.
372 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
373 execute it before loading inferior.
375 *** Changes in GDB 7.4
377 * GDB now handles ambiguous linespecs more consistently; the existing
378 FILE:LINE support has been expanded to other types of linespecs. A
379 breakpoint will now be set on all matching locations in all
380 inferiors, and locations will be added or removed according to
383 * GDB now allows you to skip uninteresting functions and files when
384 stepping with the "skip function" and "skip file" commands.
386 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
387 and "show remote hardware-watchpoint-length-limit". These allows to
388 set or show the maximum length limit (in bytes) of a remote
389 target hardware watchpoint.
391 This allows e.g. to use "unlimited" hardware watchpoints with the
392 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
393 watchpoints are slower than real hardware watchpoints but are
394 significantly faster than gdb software watchpoints.
398 ** The register_pretty_printer function in module gdb.printing now takes
399 an optional `replace' argument. If True, the new printer replaces any
402 ** The "maint set python print-stack on|off" command has been
403 deprecated and will be deleted in GDB 7.5.
404 A new command: "set python print-stack none|full|message" has
405 replaced it. Additionally, the default for "print-stack" is
406 now "message", which just prints the error message without
409 ** A prompt substitution hook (prompt_hook) is now available to the
412 ** A new Python module, gdb.prompt has been added to the GDB Python
413 modules library. This module provides functionality for
414 escape sequences in prompts (used by set/show
415 extended-prompt). These escape sequences are replaced by their
418 ** Python commands and convenience-functions located in
419 'data-directory'/python/gdb/command and
420 'data-directory'/python/gdb/function are now automatically loaded
423 ** Blocks now provide four new attributes. global_block and
424 static_block will return the global and static blocks
425 respectively. is_static and is_global are boolean attributes
426 that indicate if the block is one of those two types.
428 ** Symbols now provide the "type" attribute, the type of the symbol.
430 ** The "gdb.breakpoint" function has been deprecated in favor of
433 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
434 of a function. This class is based on the "finish" command
435 available in the CLI.
437 ** Type objects for struct and union types now allow access to
438 the fields using standard Python dictionary (mapping) methods.
439 For example, "some_type['myfield']" now works, as does
442 ** A new event "gdb.new_objfile" has been added, triggered by loading a
445 ** A new function, "deep_items" has been added to the gdb.types
446 module in the GDB Python modules library. This function returns
447 an iterator over the fields of a struct or union type. Unlike
448 the standard Python "iteritems" method, it will recursively traverse
449 any anonymous fields.
453 ** "*stopped" events can report several new "reason"s, such as
456 ** Breakpoint changes are now notified using new async records, like
457 "=breakpoint-modified".
459 ** New command -ada-task-info.
461 * libthread-db-search-path now supports two special values: $sdir and $pdir.
462 $sdir specifies the default system locations of shared libraries.
463 $pdir specifies the directory where the libpthread used by the application
466 GDB no longer looks in $sdir and $pdir after it has searched the directories
467 mentioned in libthread-db-search-path. If you want to search those
468 directories, they must be specified in libthread-db-search-path.
469 The default value of libthread-db-search-path on GNU/Linux and Solaris
470 systems is now "$sdir:$pdir".
472 $pdir is not supported by gdbserver, it is currently ignored.
473 $sdir is supported by gdbserver.
475 * New configure option --with-iconv-bin.
476 When using the internationalization support like the one in the GNU C
477 library, GDB will invoke the "iconv" program to get a list of supported
478 character sets. If this program lives in a non-standard location, one can
479 use this option to specify where to find it.
481 * When natively debugging programs on PowerPC BookE processors running
482 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
483 watchpoints, which specify a mask in addition to an address to watch.
484 The mask specifies that some bits of an address (the bits which are
485 reset in the mask) should be ignored when matching the address accessed
486 by the inferior against the watchpoint address. See the "PowerPC Embedded"
487 section in the user manual for more details.
489 * The new option --once causes GDBserver to stop listening for connections once
490 the first connection is made. The listening port used by GDBserver will
491 become available after that.
493 * New commands "info macros" and "alias" have been added.
495 * New function parameters suffix @entry specifies value of function parameter
496 at the time the function got called. Entry values are available only since
502 "!" is now an alias of the "shell" command.
503 Note that no space is needed between "!" and SHELL COMMAND.
507 watch EXPRESSION mask MASK_VALUE
508 The watch command now supports the mask argument which allows creation
509 of masked watchpoints, if the current architecture supports this feature.
511 info auto-load-scripts [REGEXP]
512 This command was formerly named "maintenance print section-scripts".
513 It is now generally useful and is no longer a maintenance-only command.
515 info macro [-all] [--] MACRO
516 The info macro command has new options `-all' and `--'. The first for
517 printing all definitions of a macro. The second for explicitly specifying
518 the end of arguments and the beginning of the macro name in case the macro
519 name starts with a hyphen.
521 collect[/s] EXPRESSIONS
522 The tracepoint collect command now takes an optional modifier "/s"
523 that directs it to dereference pointer-to-character types and
524 collect the bytes of memory up to a zero byte. The behavior is
525 similar to what you see when you use the regular print command on a
526 string. An optional integer following the "/s" sets a bound on the
527 number of bytes that will be collected.
530 The trace start command now interprets any supplied arguments as a
531 note to be recorded with the trace run, with an effect similar to
532 setting the variable trace-notes.
535 The trace stop command now interprets any arguments as a note to be
536 mentioned along with the tstatus report that the trace was stopped
537 with a command. The effect is similar to setting the variable
540 * Tracepoints can now be enabled and disabled at any time after a trace
541 experiment has been started using the standard "enable" and "disable"
542 commands. It is now possible to start a trace experiment with no enabled
543 tracepoints; GDB will display a warning, but will allow the experiment to
544 begin, assuming that tracepoints will be enabled as needed while the trace
547 * Fast tracepoints on 32-bit x86-architectures can now be placed at
548 locations with 4-byte instructions, when they were previously
549 limited to locations with instructions of 5 bytes or longer.
553 set debug dwarf2-read
554 show debug dwarf2-read
555 Turns on or off display of debugging messages related to reading
556 DWARF debug info. The default is off.
558 set debug symtab-create
559 show debug symtab-create
560 Turns on or off display of debugging messages related to symbol table
561 creation. The default is off.
565 Set the GDB prompt, and allow escape sequences to be inserted to
566 display miscellaneous information (see 'help set extended-prompt'
567 for the list of sequences). This prompt (and any information
568 accessed through the escape sequences) is updated every time the
571 set print entry-values (both|compact|default|if-needed|no|only|preferred)
572 show print entry-values
573 Set printing of frame argument values at function entry. In some cases
574 GDB can determine the value of function argument which was passed by the
575 function caller, even if the value was modified inside the called function.
577 set debug entry-values
578 show debug entry-values
579 Control display of debugging info for determining frame argument values at
580 function entry and virtual tail call frames.
582 set basenames-may-differ
583 show basenames-may-differ
584 Set whether a source file may have multiple base names.
585 (A "base name" is the name of a file with the directory part removed.
586 Example: The base name of "/home/user/hello.c" is "hello.c".)
587 If set, GDB will canonicalize file names (e.g., expand symlinks)
588 before comparing them. Canonicalization is an expensive operation,
589 but it allows the same file be known by more than one base name.
590 If not set (the default), all source files are assumed to have just
591 one base name, and gdb will do file name comparisons more efficiently.
597 Set a user name and notes for the current and any future trace runs.
598 This is useful for long-running and/or disconnected traces, to
599 inform others (or yourself) as to who is running the trace, supply
600 contact information, or otherwise explain what is going on.
603 show trace-stop-notes
604 Set a note attached to the trace run, that is displayed when the
605 trace has been stopped by a tstop command. This is useful for
606 instance as an explanation, if you are stopping a trace run that was
607 started by someone else.
613 Dynamically enable a tracepoint in a started trace experiment.
617 Dynamically disable a tracepoint in a started trace experiment.
621 Set the user and notes of the trace run.
625 Query the current status of a tracepoint.
629 Query the minimum length of instruction at which a fast tracepoint may
632 * Dcache size (number of lines) and line-size are now runtime-configurable
633 via "set dcache line" and "set dcache line-size" commands.
637 Texas Instruments TMS320C6x tic6x-*-*
641 Renesas RL78 rl78-*-elf
643 *** Changes in GDB 7.3.1
645 * The build failure for NetBSD and OpenBSD targets have now been fixed.
647 *** Changes in GDB 7.3
649 * GDB has a new command: "thread find [REGEXP]".
650 It finds the thread id whose name, target id, or thread extra info
651 matches the given regular expression.
653 * The "catch syscall" command now works on mips*-linux* targets.
655 * The -data-disassemble MI command now supports modes 2 and 3 for
656 dumping the instruction opcodes.
658 * New command line options
660 -data-directory DIR Specify DIR as the "data-directory".
661 This is mostly for testing purposes.
663 * The "maint set python auto-load on|off" command has been renamed to
664 "set auto-load-scripts on|off".
666 * GDB has a new command: "set directories".
667 It is like the "dir" command except that it replaces the
668 source path list instead of augmenting it.
670 * GDB now understands thread names.
672 On GNU/Linux, "info threads" will display the thread name as set by
673 prctl or pthread_setname_np.
675 There is also a new command, "thread name", which can be used to
676 assign a name internally for GDB to display.
679 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
680 has been integrated into GDB.
684 ** The function gdb.Write now accepts an optional keyword 'stream'.
685 This keyword, when provided, will direct the output to either
686 stdout, stderr, or GDB's logging output.
688 ** Parameters can now be be sub-classed in Python, and in particular
689 you may implement the get_set_doc and get_show_doc functions.
690 This improves how Parameter set/show documentation is processed
691 and allows for more dynamic content.
693 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
694 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
695 have an is_valid method.
697 ** Breakpoints can now be sub-classed in Python, and in particular
698 you may implement a 'stop' function that is executed each time
699 the inferior reaches that breakpoint.
701 ** New function gdb.lookup_global_symbol looks up a global symbol.
703 ** GDB values in Python are now callable if the value represents a
704 function. For example, if 'some_value' represents a function that
705 takes two integer parameters and returns a value, you can call
706 that function like so:
708 result = some_value (10,20)
710 ** Module gdb.types has been added.
711 It contains a collection of utilities for working with gdb.Types objects:
712 get_basic_type, has_field, make_enum_dict.
714 ** Module gdb.printing has been added.
715 It contains utilities for writing and registering pretty-printers.
716 New classes: PrettyPrinter, SubPrettyPrinter,
717 RegexpCollectionPrettyPrinter.
718 New function: register_pretty_printer.
720 ** New commands "info pretty-printers", "enable pretty-printer" and
721 "disable pretty-printer" have been added.
723 ** gdb.parameter("directories") is now available.
725 ** New function gdb.newest_frame returns the newest frame in the
728 ** The gdb.InferiorThread class has a new "name" attribute. This
729 holds the thread's name.
731 ** Python Support for Inferior events.
732 Python scripts can add observers to be notified of events
733 occurring in the process being debugged.
734 The following events are currently supported:
735 - gdb.events.cont Continue event.
736 - gdb.events.exited Inferior exited event.
737 - gdb.events.stop Signal received, and Breakpoint hit events.
741 ** GDB now puts template parameters in scope when debugging in an
742 instantiation. For example, if you have:
744 template<int X> int func (void) { return X; }
746 then if you step into func<5>, "print X" will show "5". This
747 feature requires proper debuginfo support from the compiler; it
748 was added to GCC 4.5.
750 ** The motion commands "next", "finish", "until", and "advance" now
751 work better when exceptions are thrown. In particular, GDB will
752 no longer lose control of the inferior; instead, the GDB will
753 stop the inferior at the point at which the exception is caught.
754 This functionality requires a change in the exception handling
755 code that was introduced in GCC 4.5.
757 * GDB now follows GCC's rules on accessing volatile objects when
758 reading or writing target state during expression evaluation.
759 One notable difference to prior behavior is that "print x = 0"
760 no longer generates a read of x; the value of the assignment is
761 now always taken directly from the value being assigned.
763 * GDB now has some support for using labels in the program's source in
764 linespecs. For instance, you can use "advance label" to continue
765 execution to a label.
767 * GDB now has support for reading and writing a new .gdb_index
768 section. This section holds a fast index of DWARF debugging
769 information and can be used to greatly speed up GDB startup and
770 operation. See the documentation for `save gdb-index' for details.
772 * The "watch" command now accepts an optional "-location" argument.
773 When used, this causes GDB to watch the memory referred to by the
774 expression. Such a watchpoint is never deleted due to it going out
777 * GDB now supports thread debugging of core dumps on GNU/Linux.
779 GDB now activates thread debugging using the libthread_db library
780 when debugging GNU/Linux core dumps, similarly to when debugging
781 live processes. As a result, when debugging a core dump file, GDB
782 is now able to display pthread_t ids of threads. For example, "info
783 threads" shows the same output as when debugging the process when it
784 was live. In earlier releases, you'd see something like this:
787 * 1 LWP 6780 main () at main.c:10
789 While now you see this:
792 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
794 It is also now possible to inspect TLS variables when debugging core
797 When debugging a core dump generated on a machine other than the one
798 used to run GDB, you may need to point GDB at the correct
799 libthread_db library with the "set libthread-db-search-path"
800 command. See the user manual for more details on this command.
802 * When natively debugging programs on PowerPC BookE processors running
803 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
804 which stop execution of the inferior whenever it executes an instruction
805 at any address within the specified range. See the "PowerPC Embedded"
806 section in the user manual for more details.
808 * New features in the GDB remote stub, GDBserver
810 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
811 and i686 LynxOS (version 5.x).
813 ** GDBserver is now supported on Blackfin Linux.
815 * New native configurations
817 ia64 HP-UX ia64-*-hpux*
821 Analog Devices, Inc. Blackfin Processor bfin-*
823 * Ada task switching is now supported on sparc-elf targets when
824 debugging a program using the Ravenscar Profile. For more information,
825 see the "Tasking Support when using the Ravenscar Profile" section
826 in the GDB user manual.
828 * Guile support was removed.
830 * New features in the GNU simulator
832 ** The --map-info flag lists all known core mappings.
834 ** CFI flashes may be simulated via the "cfi" device.
836 *** Changes in GDB 7.2
838 * Shared library support for remote targets by default
840 When GDB is configured for a generic, non-OS specific target, like
841 for example, --target=arm-eabi or one of the many *-*-elf targets,
842 GDB now queries remote stubs for loaded shared libraries using the
843 `qXfer:libraries:read' packet. Previously, shared library support
844 was always disabled for such configurations.
848 ** Argument Dependent Lookup (ADL)
850 In C++ ADL lookup directs function search to the namespaces of its
851 arguments even if the namespace has not been imported.
861 Here the compiler will search for `foo' in the namespace of 'b'
862 and find A::foo. GDB now supports this. This construct is commonly
863 used in the Standard Template Library for operators.
865 ** Improved User Defined Operator Support
867 In addition to member operators, GDB now supports lookup of operators
868 defined in a namespace and imported with a `using' directive, operators
869 defined in the global scope, operators imported implicitly from an
870 anonymous namespace, and the ADL operators mentioned in the previous
872 GDB now also supports proper overload resolution for all the previously
873 mentioned flavors of operators.
875 ** static const class members
877 Printing of static const class members that are initialized in the
878 class definition has been fixed.
880 * Windows Thread Information Block access.
882 On Windows targets, GDB now supports displaying the Windows Thread
883 Information Block (TIB) structure. This structure is visible either
884 by using the new command `info w32 thread-information-block' or, by
885 dereferencing the new convenience variable named `$_tlb', a
886 thread-specific pointer to the TIB. This feature is also supported
887 when remote debugging using GDBserver.
891 Static tracepoints are calls in the user program into a tracing
892 library. One such library is a port of the LTTng kernel tracer to
893 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
894 When debugging with GDBserver, GDB now supports combining the GDB
895 tracepoint machinery with such libraries. For example: the user can
896 use GDB to probe a static tracepoint marker (a call from the user
897 program into the tracing library) with the new "strace" command (see
898 "New commands" below). This creates a "static tracepoint" in the
899 breakpoint list, that can be manipulated with the same feature set
900 as fast and regular tracepoints. E.g., collect registers, local and
901 global variables, collect trace state variables, and define
902 tracepoint conditions. In addition, the user can collect extra
903 static tracepoint marker specific data, by collecting the new
904 $_sdata internal variable. When analyzing the trace buffer, you can
905 inspect $_sdata like any other variable available to GDB. For more
906 information, see the "Tracepoints" chapter in GDB user manual. New
907 remote packets have been defined to support static tracepoints, see
908 the "New remote packets" section below.
910 * Better reconstruction of tracepoints after disconnected tracing
912 GDB will attempt to download the original source form of tracepoint
913 definitions when starting a trace run, and then will upload these
914 upon reconnection to the target, resulting in a more accurate
915 reconstruction of the tracepoints that are in use on the target.
919 You can now exercise direct control over the ways that GDB can
920 affect your program. For instance, you can disallow the setting of
921 breakpoints, so that the program can run continuously (assuming
922 non-stop mode). In addition, the "observer" variable is available
923 to switch all of the different controls; in observer mode, GDB
924 cannot affect the target's behavior at all, which is useful for
925 tasks like diagnosing live systems in the field.
927 * The new convenience variable $_thread holds the number of the
934 Return the address of the Windows Thread Information Block of a given thread.
938 In response to several of the tracepoint packets, the target may now
939 also respond with a number of intermediate `qRelocInsn' request
940 packets before the final result packet, to have GDB handle
941 relocating an instruction to execute at a different address. This
942 is particularly useful for stubs that support fast tracepoints. GDB
943 reports support for this feature in the qSupported packet.
947 List static tracepoint markers in the target program.
951 List static tracepoint markers at a given address in the target
954 qXfer:statictrace:read
956 Read the static trace data collected (by a `collect $_sdata'
957 tracepoint action). The remote stub reports support for this packet
958 to gdb's qSupported query.
962 Send the current settings of GDB's permission flags.
966 Send part of the source (textual) form of a tracepoint definition,
967 which includes location, conditional, and action list.
969 * The source command now accepts a -s option to force searching for the
970 script in the source search path even if the script name specifies
973 * New features in the GDB remote stub, GDBserver
975 - GDBserver now support tracepoints (including fast tracepoints, and
976 static tracepoints). The feature is currently supported by the
977 i386-linux and amd64-linux builds. See the "Tracepoints support
978 in gdbserver" section in the manual for more information.
980 GDBserver JIT compiles the tracepoint's conditional agent
981 expression bytecode into native code whenever possible for low
982 overhead dynamic tracepoints conditionals. For such tracepoints,
983 an expression that examines program state is evaluated when the
984 tracepoint is reached, in order to determine whether to capture
985 trace data. If the condition is simple and false, processing the
986 tracepoint finishes very quickly and no data is gathered.
988 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
989 for static tracepoints support.
991 - GDBserver now supports x86_64 Windows 64-bit debugging.
993 * GDB now sends xmlRegisters= in qSupported packet to indicate that
994 it understands register description.
996 * The --batch flag now disables pagination and queries.
998 * X86 general purpose registers
1000 GDB now supports reading/writing byte, word and double-word x86
1001 general purpose registers directly. This means you can use, say,
1002 $ah or $ax to refer, respectively, to the byte register AH and
1003 16-bit word register AX that are actually portions of the 32-bit
1004 register EAX or 64-bit register RAX.
1006 * The `commands' command now accepts a range of breakpoints to modify.
1007 A plain `commands' following a command that creates multiple
1008 breakpoints affects all the breakpoints set by that command. This
1009 applies to breakpoints set by `rbreak', and also applies when a
1010 single `break' command creates multiple breakpoints (e.g.,
1011 breakpoints on overloaded c++ functions).
1013 * The `rbreak' command now accepts a filename specification as part of
1014 its argument, limiting the functions selected by the regex to those
1015 in the specified file.
1017 * Support for remote debugging Windows and SymbianOS shared libraries
1018 from Unix hosts has been improved. Non Windows GDB builds now can
1019 understand target reported file names that follow MS-DOS based file
1020 system semantics, such as file names that include drive letters and
1021 use the backslash character as directory separator. This makes it
1022 possible to transparently use the "set sysroot" and "set
1023 solib-search-path" on Unix hosts to point as host copies of the
1024 target's shared libraries. See the new command "set
1025 target-file-system-kind" described below, and the "Commands to
1026 specify files" section in the user manual for more information.
1030 eval template, expressions...
1031 Convert the values of one or more expressions under the control
1032 of the string template to a command line, and call it.
1034 set target-file-system-kind unix|dos-based|auto
1035 show target-file-system-kind
1036 Set or show the assumed file system kind for target reported file
1039 save breakpoints <filename>
1040 Save all current breakpoint definitions to a file suitable for use
1041 in a later debugging session. To read the saved breakpoint
1042 definitions, use the `source' command.
1044 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1047 info static-tracepoint-markers
1048 Display information about static tracepoint markers in the target.
1050 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1051 Define a static tracepoint by probing a marker at the given
1052 function, line, address, or marker ID.
1056 Enable and disable observer mode.
1058 set may-write-registers on|off
1059 set may-write-memory on|off
1060 set may-insert-breakpoints on|off
1061 set may-insert-tracepoints on|off
1062 set may-insert-fast-tracepoints on|off
1063 set may-interrupt on|off
1064 Set individual permissions for GDB effects on the target. Note that
1065 some of these settings can have undesirable or surprising
1066 consequences, particularly when changed in the middle of a session.
1067 For instance, disabling the writing of memory can prevent
1068 breakpoints from being inserted, cause single-stepping to fail, or
1069 even crash your program, if you disable after breakpoints have been
1070 inserted. However, GDB should not crash.
1072 set record memory-query on|off
1073 show record memory-query
1074 Control whether to stop the inferior if memory changes caused
1075 by an instruction cannot be recorded.
1080 The disassemble command now supports "start,+length" form of two arguments.
1084 ** GDB now provides a new directory location, called the python directory,
1085 where Python scripts written for GDB can be installed. The location
1086 of that directory is <data-directory>/python, where <data-directory>
1087 is the GDB data directory. For more details, see section `Scripting
1088 GDB using Python' in the manual.
1090 ** The GDB Python API now has access to breakpoints, symbols, symbol
1091 tables, program spaces, inferiors, threads and frame's code blocks.
1092 Additionally, GDB Parameters can now be created from the API, and
1093 manipulated via set/show in the CLI.
1095 ** New functions gdb.target_charset, gdb.target_wide_charset,
1096 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1098 ** New exception gdb.GdbError.
1100 ** Pretty-printers are now also looked up in the current program space.
1102 ** Pretty-printers can now be individually enabled and disabled.
1104 ** GDB now looks for names of Python scripts to auto-load in a
1105 special section named `.debug_gdb_scripts', in addition to looking
1106 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1108 * Tracepoint actions were unified with breakpoint commands. In particular,
1109 there are no longer differences in "info break" output for breakpoints and
1110 tracepoints and the "commands" command can be used for both tracepoints and
1111 regular breakpoints.
1115 ARM Symbian arm*-*-symbianelf*
1117 * D language support.
1118 GDB now supports debugging programs written in the D programming
1121 * GDB now supports the extended ptrace interface for PowerPC which is
1122 available since Linux kernel version 2.6.34. This automatically enables
1123 any hardware breakpoints and additional hardware watchpoints available in
1124 the processor. The old ptrace interface exposes just one hardware
1125 watchpoint and no hardware breakpoints.
1127 * GDB is now able to use the Data Value Compare (DVC) register available on
1128 embedded PowerPC processors to implement in hardware simple watchpoint
1129 conditions of the form:
1131 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1133 This works in native GDB running on Linux kernels with the extended ptrace
1134 interface mentioned above.
1136 *** Changes in GDB 7.1
1140 ** Namespace Support
1142 GDB now supports importing of namespaces in C++. This enables the
1143 user to inspect variables from imported namespaces. Support for
1144 namepace aliasing has also been added. So, if a namespace is
1145 aliased in the current scope (e.g. namepace C=A; ) the user can
1146 print variables using the alias (e.g. (gdb) print C::x).
1150 All known bugs relating to the printing of virtual base class were
1151 fixed. It is now possible to call overloaded static methods using a
1156 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1157 and reinterpret_cast<> are now handled by the C++ expression parser.
1161 Xilinx MicroBlaze microblaze-*-*
1166 Xilinx MicroBlaze microblaze
1169 * Multi-program debugging.
1171 GDB now has support for multi-program (a.k.a. multi-executable or
1172 multi-exec) debugging. This allows for debugging multiple inferiors
1173 simultaneously each running a different program under the same GDB
1174 session. See "Debugging Multiple Inferiors and Programs" in the
1175 manual for more information. This implied some user visible changes
1176 in the multi-inferior support. For example, "info inferiors" now
1177 lists inferiors that are not running yet or that have exited
1178 already. See also "New commands" and "New options" below.
1180 * New tracing features
1182 GDB's tracepoint facility now includes several new features:
1184 ** Trace state variables
1186 GDB tracepoints now include support for trace state variables, which
1187 are variables managed by the target agent during a tracing
1188 experiment. They are useful for tracepoints that trigger each
1189 other, so for instance one tracepoint can count hits in a variable,
1190 and then a second tracepoint has a condition that is true when the
1191 count reaches a particular value. Trace state variables share the
1192 $-syntax of GDB convenience variables, and can appear in both
1193 tracepoint actions and condition expressions. Use the "tvariable"
1194 command to create, and "info tvariables" to view; see "Trace State
1195 Variables" in the manual for more detail.
1199 GDB now includes an option for defining fast tracepoints, which
1200 targets may implement more efficiently, such as by installing a jump
1201 into the target agent rather than a trap instruction. The resulting
1202 speedup can be by two orders of magnitude or more, although the
1203 tradeoff is that some program locations on some target architectures
1204 might not allow fast tracepoint installation, for instance if the
1205 instruction to be replaced is shorter than the jump. To request a
1206 fast tracepoint, use the "ftrace" command, with syntax identical to
1207 the regular trace command.
1209 ** Disconnected tracing
1211 It is now possible to detach GDB from the target while it is running
1212 a trace experiment, then reconnect later to see how the experiment
1213 is going. In addition, a new variable disconnected-tracing lets you
1214 tell the target agent whether to continue running a trace if the
1215 connection is lost unexpectedly.
1219 GDB now has the ability to save the trace buffer into a file, and
1220 then use that file as a target, similarly to you can do with
1221 corefiles. You can select trace frames, print data that was
1222 collected in them, and use tstatus to display the state of the
1223 tracing run at the moment that it was saved. To create a trace
1224 file, use "tsave <filename>", and to use it, do "target tfile
1227 ** Circular trace buffer
1229 You can ask the target agent to handle the trace buffer as a
1230 circular buffer, discarding the oldest trace frames to make room for
1231 newer ones, by setting circular-trace-buffer to on. This feature may
1232 not be available for all target agents.
1237 The disassemble command, when invoked with two arguments, now requires
1238 the arguments to be comma-separated.
1241 The info variables command now displays variable definitions. Files
1242 which only declare a variable are not shown.
1245 The source command is now capable of sourcing Python scripts.
1246 This feature is dependent on the debugger being build with Python
1249 Related to this enhancement is also the introduction of a new command
1250 "set script-extension" (see below).
1252 * New commands (for set/show, see "New options" below)
1254 record save [<FILENAME>]
1255 Save a file (in core file format) containing the process record
1256 execution log for replay debugging at a later time.
1258 record restore <FILENAME>
1259 Restore the process record execution log that was saved at an
1260 earlier time, for replay debugging.
1262 add-inferior [-copies <N>] [-exec <FILENAME>]
1265 clone-inferior [-copies <N>] [ID]
1266 Make a new inferior ready to execute the same program another
1267 inferior has loaded.
1272 maint info program-spaces
1273 List the program spaces loaded into GDB.
1275 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1276 show remote interrupt-sequence
1277 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1278 as the sequence to the remote target in order to interrupt the execution.
1279 Ctrl-C is a default. Some system prefers BREAK which is high level of
1280 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1281 Magic SysRq g. It is BREAK signal and character 'g'.
1283 set remote interrupt-on-connect [on | off]
1284 show remote interrupt-on-connect
1285 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1286 remote target when gdb connects to it. This is needed when you debug
1289 set remotebreak [on | off]
1291 Deprecated. Use "set/show remote interrupt-sequence" instead.
1293 tvariable $NAME [ = EXP ]
1294 Create or modify a trace state variable.
1297 List trace state variables and their values.
1299 delete tvariable $NAME ...
1300 Delete one or more trace state variables.
1303 Evaluate the given expressions without collecting anything into the
1304 trace buffer. (Valid in tracepoint actions only.)
1306 ftrace FN / FILE:LINE / *ADDR
1307 Define a fast tracepoint at the given function, line, or address.
1309 * New expression syntax
1311 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1312 GDB now parses 0b101010 identically with 42.
1316 set follow-exec-mode new|same
1317 show follow-exec-mode
1318 Control whether GDB reuses the same inferior across an exec call or
1319 creates a new one. This is useful to be able to restart the old
1320 executable after the inferior having done an exec call.
1322 set default-collect EXPR, ...
1323 show default-collect
1324 Define a list of expressions to be collected at each tracepoint.
1325 This is a useful way to ensure essential items are not overlooked,
1326 such as registers or a critical global variable.
1328 set disconnected-tracing
1329 show disconnected-tracing
1330 If set to 1, the target is instructed to continue tracing if it
1331 loses its connection to GDB. If 0, the target is to stop tracing
1334 set circular-trace-buffer
1335 show circular-trace-buffer
1336 If set to on, the target is instructed to use a circular trace buffer
1337 and discard the oldest trace frames instead of stopping the trace due
1338 to a full trace buffer. If set to off, the trace stops when the buffer
1339 fills up. Some targets may not support this.
1341 set script-extension off|soft|strict
1342 show script-extension
1343 If set to "off", the debugger does not perform any script language
1344 recognition, and all sourced files are assumed to be GDB scripts.
1345 If set to "soft" (the default), files are sourced according to
1346 filename extension, falling back to GDB scripts if the first
1348 If set to "strict", files are sourced according to filename extension.
1350 set ada trust-PAD-over-XVS on|off
1351 show ada trust-PAD-over-XVS
1352 If off, activate a workaround against a bug in the debugging information
1353 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1354 the GCC sources for more information about the GNAT encoding and
1355 PAD types in particular). It is always safe to set this option to
1356 off, but this introduces a slight performance penalty. The default
1359 * Python API Improvements
1361 ** GDB provides the new class gdb.LazyString. This is useful in
1362 some pretty-printing cases. The new method gdb.Value.lazy_string
1363 provides a simple way to create objects of this type.
1365 ** The fields returned by gdb.Type.fields now have an
1366 `is_base_class' attribute.
1368 ** The new method gdb.Type.range returns the range of an array type.
1370 ** The new method gdb.parse_and_eval can be used to parse and
1371 evaluate an expression.
1373 * New remote packets
1376 Define a trace state variable.
1379 Get the current value of a trace state variable.
1382 Set desired tracing behavior upon disconnection.
1385 Set the trace buffer to be linear or circular.
1388 Get data about the tracepoints currently in use.
1392 Process record now works correctly with hardware watchpoints.
1394 Multiple bug fixes have been made to the mips-irix port, making it
1395 much more reliable. In particular:
1396 - Debugging threaded applications is now possible again. Previously,
1397 GDB would hang while starting the program, or while waiting for
1398 the program to stop at a breakpoint.
1399 - Attaching to a running process no longer hangs.
1400 - An error occurring while loading a core file has been fixed.
1401 - Changing the value of the PC register now works again. This fixes
1402 problems observed when using the "jump" command, or when calling
1403 a function from GDB, or even when assigning a new value to $pc.
1404 - With the "finish" and "return" commands, the return value for functions
1405 returning a small array is now correctly printed.
1406 - It is now possible to break on shared library code which gets executed
1407 during a shared library init phase (code executed while executing
1408 their .init section). Previously, the breakpoint would have no effect.
1409 - GDB is now able to backtrace through the signal handler for
1410 non-threaded programs.
1412 PIE (Position Independent Executable) programs debugging is now supported.
1413 This includes debugging execution of PIC (Position Independent Code) shared
1414 libraries although for that, it should be possible to run such libraries as an
1417 *** Changes in GDB 7.0
1419 * GDB now has an interface for JIT compilation. Applications that
1420 dynamically generate code can create symbol files in memory and register
1421 them with GDB. For users, the feature should work transparently, and
1422 for JIT developers, the interface is documented in the GDB manual in the
1423 "JIT Compilation Interface" chapter.
1425 * Tracepoints may now be conditional. The syntax is as for
1426 breakpoints; either an "if" clause appended to the "trace" command,
1427 or the "condition" command is available. GDB sends the condition to
1428 the target for evaluation using the same bytecode format as is used
1429 for tracepoint actions.
1431 * The disassemble command now supports: an optional /r modifier, print the
1432 raw instructions in hex as well as in symbolic form, and an optional /m
1433 modifier to print mixed source+assembly.
1435 * Process record and replay
1437 In a architecture environment that supports ``process record and
1438 replay'', ``process record and replay'' target can record a log of
1439 the process execution, and replay it with both forward and reverse
1442 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1443 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1444 set execution-direction {forward|reverse}, for targets that support
1447 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1448 feature is available with a native GDB running on kernel version
1451 * GDB now has support for multi-byte and wide character sets on the
1452 target. Strings whose character type is wchar_t, char16_t, or
1453 char32_t are now correctly printed. GDB supports wide- and unicode-
1454 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1455 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1456 `printf'. This feature requires iconv to work properly; if your
1457 system does not have a working iconv, GDB can use GNU libiconv. See
1458 the installation instructions for more information.
1460 * GDB now supports automatic retrieval of shared library files from
1461 remote targets. To use this feature, specify a system root that begins
1462 with the `remote:' prefix, either via the `set sysroot' command or via
1463 the `--with-sysroot' configure-time option.
1465 * "info sharedlibrary" now takes an optional regex of libraries to show,
1466 and it now reports if a shared library has no debugging information.
1468 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1469 now complete on file names.
1471 * When completing in expressions, gdb will attempt to limit
1472 completions to allowable structure or union fields, where appropriate.
1473 For instance, consider:
1475 # struct example { int f1; double f2; };
1476 # struct example variable;
1479 If the user types TAB at the end of this command line, the available
1480 completions will be "f1" and "f2".
1482 * Inlined functions are now supported. They show up in backtraces, and
1483 the "step", "next", and "finish" commands handle them automatically.
1485 * GDB now supports the token-splicing (##) and stringification (#)
1486 operators when expanding macros. It also supports variable-arity
1489 * GDB now supports inspecting extra signal information, exported by
1490 the new $_siginfo convenience variable. The feature is currently
1491 implemented on linux ARM, i386 and amd64.
1493 * GDB can now display the VFP floating point registers and NEON vector
1494 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1495 can provide these registers (requires Linux 2.6.30 or later). Remote
1496 and simulator targets may also provide them.
1498 * New remote packets
1501 Search memory for a sequence of bytes.
1504 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1505 operation over reliable transport links. Use of this packet is
1506 controlled by the `set remote noack-packet' command.
1509 Kill the process with the specified process ID. Use this in preference
1510 to `k' when multiprocess protocol extensions are supported.
1513 Obtains additional operating system information
1517 Read or write additional signal information.
1519 * Removed remote protocol undocumented extension
1521 An undocumented extension to the remote protocol's `S' stop reply
1522 packet that permited the stub to pass a process id was removed.
1523 Remote servers should use the `T' stop reply packet instead.
1525 * GDB now supports multiple function calling conventions according to the
1526 DWARF-2 DW_AT_calling_convention function attribute.
1528 * The SH target utilizes the aforementioned change to distinguish between gcc
1529 and Renesas calling convention. It also adds the new CLI commands
1530 `set/show sh calling-convention'.
1532 * GDB can now read compressed debug sections, as produced by GNU gold
1533 with the --compress-debug-sections=zlib flag.
1535 * 64-bit core files are now supported on AIX.
1537 * Thread switching is now supported on Tru64.
1539 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1540 which will be allocated using malloc later in program execution.
1542 * The qXfer:libraries:read remote procotol packet now allows passing a
1543 list of section offsets.
1545 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1546 conditions handling signals delivered during attach or thread creation
1547 have also been fixed.
1549 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1550 From the user's standpoint, all unqualified instances of True and False
1551 are treated as the standard definitions, regardless of context.
1553 * GDB now parses C++ symbol and type names more flexibly. For
1556 template<typename T> class C { };
1559 GDB will now correctly handle all of:
1561 ptype C<char const *>
1562 ptype C<char const*>
1563 ptype C<const char *>
1564 ptype C<const char*>
1566 * New features in the GDB remote stub, gdbserver
1568 - The "--wrapper" command-line argument tells gdbserver to use a
1569 wrapper program to launch programs for debugging.
1571 - On PowerPC and S/390 targets, it is now possible to use a single
1572 gdbserver executable to debug both 32-bit and 64-bit programs.
1573 (This requires gdbserver itself to be built as a 64-bit executable.)
1575 - gdbserver uses the new noack protocol mode for TCP connections to
1576 reduce communications latency, if also supported and enabled in GDB.
1578 - Support for the sparc64-linux-gnu target is now included in
1581 - The amd64-linux build of gdbserver now supports debugging both
1582 32-bit and 64-bit programs.
1584 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1585 now support hardware watchpoints, and will use them automatically
1590 GDB now has support for scripting using Python. Whether this is
1591 available is determined at configure time.
1593 New GDB commands can now be written in Python.
1595 * Ada tasking support
1597 Ada tasks can now be inspected in GDB. The following commands have
1601 Print the list of Ada tasks.
1603 Print detailed information about task number N.
1605 Print the task number of the current task.
1607 Switch the context of debugging to task number N.
1609 * Support for user-defined prefixed commands. The "define" command can
1610 add new commands to existing prefixes, e.g. "target".
1612 * Multi-inferior, multi-process debugging.
1614 GDB now has generalized support for multi-inferior debugging. See
1615 "Debugging Multiple Inferiors" in the manual for more information.
1616 Although availability still depends on target support, the command
1617 set is more uniform now. The GNU/Linux specific multi-forks support
1618 has been migrated to this new framework. This implied some user
1619 visible changes; see "New commands" and also "Removed commands"
1622 * Target descriptions can now describe the target OS ABI. See the
1623 "Target Description Format" section in the user manual for more
1626 * Target descriptions can now describe "compatible" architectures
1627 to indicate that the target can execute applications for a different
1628 architecture in addition to those for the main target architecture.
1629 See the "Target Description Format" section in the user manual for
1632 * Multi-architecture debugging.
1634 GDB now includes general supports for debugging applications on
1635 hybrid systems that use more than one single processor architecture
1636 at the same time. Each such hybrid architecture still requires
1637 specific support to be added. The only hybrid architecture supported
1638 in this version of GDB is the Cell Broadband Engine.
1640 * GDB now supports integrated debugging of Cell/B.E. applications that
1641 use both the PPU and SPU architectures. To enable support for hybrid
1642 Cell/B.E. debugging, you need to configure GDB to support both the
1643 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1644 --enable-targets configure option.
1646 * Non-stop mode debugging.
1648 For some targets, GDB now supports an optional mode of operation in
1649 which you can examine stopped threads while other threads continue
1650 to execute freely. This is referred to as non-stop mode, with the
1651 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1652 section in the user manual for more information.
1654 To be able to support remote non-stop debugging, a remote stub needs
1655 to implement the non-stop mode remote protocol extensions, as
1656 described in the "Remote Non-Stop" section of the user manual. The
1657 GDB remote stub, gdbserver, has been adjusted to support these
1658 extensions on linux targets.
1660 * New commands (for set/show, see "New options" below)
1662 catch syscall [NAME(S) | NUMBER(S)]
1663 Catch system calls. Arguments, which should be names of system
1664 calls or their numbers, mean catch only those syscalls. Without
1665 arguments, every syscall will be caught. When the inferior issues
1666 any of the specified syscalls, GDB will stop and announce the system
1667 call, both when it is called and when its call returns. This
1668 feature is currently available with a native GDB running on the
1669 Linux Kernel, under the following architectures: x86, x86_64,
1670 PowerPC and PowerPC64.
1672 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1674 Search memory for a sequence of bytes.
1676 maint set python print-stack
1677 maint show python print-stack
1678 Show a stack trace when an error is encountered in a Python script.
1681 Invoke CODE by passing it to the Python interpreter.
1686 These allow macros to be defined, undefined, and listed
1690 Show operating system information about processes.
1693 List the inferiors currently under GDB's control.
1696 Switch focus to inferior number NUM.
1699 Detach from inferior number NUM.
1702 Kill inferior number NUM.
1706 set spu stop-on-load
1707 show spu stop-on-load
1708 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1710 set spu auto-flush-cache
1711 show spu auto-flush-cache
1712 Control whether to automatically flush the software-managed cache
1713 during Cell/B.E. debugging.
1715 set sh calling-convention
1716 show sh calling-convention
1717 Control the calling convention used when calling SH target functions.
1720 show debug timestamp
1721 Control display of timestamps with GDB debugging output.
1723 set disassemble-next-line
1724 show disassemble-next-line
1725 Control display of disassembled source lines or instructions when
1728 set remote noack-packet
1729 show remote noack-packet
1730 Set/show the use of remote protocol QStartNoAckMode packet. See above
1731 under "New remote packets."
1733 set remote query-attached-packet
1734 show remote query-attached-packet
1735 Control use of remote protocol `qAttached' (query-attached) packet.
1737 set remote read-siginfo-object
1738 show remote read-siginfo-object
1739 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1742 set remote write-siginfo-object
1743 show remote write-siginfo-object
1744 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1747 set remote reverse-continue
1748 show remote reverse-continue
1749 Control use of remote protocol 'bc' (reverse-continue) packet.
1751 set remote reverse-step
1752 show remote reverse-step
1753 Control use of remote protocol 'bs' (reverse-step) packet.
1755 set displaced-stepping
1756 show displaced-stepping
1757 Control displaced stepping mode. Displaced stepping is a way to
1758 single-step over breakpoints without removing them from the debuggee.
1759 Also known as "out-of-line single-stepping".
1762 show debug displaced
1763 Control display of debugging info for displaced stepping.
1765 maint set internal-error
1766 maint show internal-error
1767 Control what GDB does when an internal error is detected.
1769 maint set internal-warning
1770 maint show internal-warning
1771 Control what GDB does when an internal warning is detected.
1776 Use a wrapper program to launch programs for debugging.
1778 set multiple-symbols (all|ask|cancel)
1779 show multiple-symbols
1780 The value of this variable can be changed to adjust the debugger behavior
1781 when an expression or a breakpoint location contains an ambiguous symbol
1782 name (an overloaded function name, for instance).
1784 set breakpoint always-inserted
1785 show breakpoint always-inserted
1786 Keep breakpoints always inserted in the target, as opposed to inserting
1787 them when resuming the target, and removing them when the target stops.
1788 This option can improve debugger performance on slow remote targets.
1790 set arm fallback-mode (arm|thumb|auto)
1791 show arm fallback-mode
1792 set arm force-mode (arm|thumb|auto)
1794 These commands control how ARM GDB determines whether instructions
1795 are ARM or Thumb. The default for both settings is auto, which uses
1796 the current CPSR value for instructions without symbols; previous
1797 versions of GDB behaved as if "set arm fallback-mode arm".
1799 set disable-randomization
1800 show disable-randomization
1801 Standalone programs run with the virtual address space randomization enabled
1802 by default on some platforms. This option keeps the addresses stable across
1803 multiple debugging sessions.
1807 Control whether other threads are stopped or not when some thread hits
1812 Requests that asynchronous execution is enabled in the target, if available.
1813 In this case, it's possible to resume target in the background, and interact
1814 with GDB while the target is running. "show target-async" displays the
1815 current state of asynchronous execution of the target.
1817 set target-wide-charset
1818 show target-wide-charset
1819 The target-wide-charset is the name of the character set that GDB
1820 uses when printing characters whose type is wchar_t.
1822 set tcp auto-retry (on|off)
1824 set tcp connect-timeout
1825 show tcp connect-timeout
1826 These commands allow GDB to retry failed TCP connections to a remote stub
1827 with a specified timeout period; this is useful if the stub is launched
1828 in parallel with GDB but may not be ready to accept connections immediately.
1830 set libthread-db-search-path
1831 show libthread-db-search-path
1832 Control list of directories which GDB will search for appropriate
1835 set schedule-multiple (on|off)
1836 show schedule-multiple
1837 Allow GDB to resume all threads of all processes or only threads of
1838 the current process.
1842 Use more aggressive caching for accesses to the stack. This improves
1843 performance of remote debugging (particularly backtraces) without
1844 affecting correctness.
1846 set interactive-mode (on|off|auto)
1847 show interactive-mode
1848 Control whether GDB runs in interactive mode (on) or not (off).
1849 When in interactive mode, GDB waits for the user to answer all
1850 queries. Otherwise, GDB does not wait and assumes the default
1851 answer. When set to auto (the default), GDB determines which
1852 mode to use based on the stdin settings.
1857 For program forks, this is replaced by the new more generic `info
1858 inferiors' command. To list checkpoints, you can still use the
1859 `info checkpoints' command, which was an alias for the `info forks'
1863 Replaced by the new `inferior' command. To switch between
1864 checkpoints, you can still use the `restart' command, which was an
1865 alias for the `fork' command.
1868 This is removed, since some targets don't have a notion of
1869 processes. To switch between processes, you can still use the
1870 `inferior' command using GDB's own inferior number.
1873 For program forks, this is replaced by the new more generic `kill
1874 inferior' command. To delete a checkpoint, you can still use the
1875 `delete checkpoint' command, which was an alias for the `delete
1879 For program forks, this is replaced by the new more generic `detach
1880 inferior' command. To detach a checkpoint, you can still use the
1881 `detach checkpoint' command, which was an alias for the `detach
1884 * New native configurations
1886 x86/x86_64 Darwin i[34567]86-*-darwin*
1888 x86_64 MinGW x86_64-*-mingw*
1892 Lattice Mico32 lm32-*
1893 x86 DICOS i[34567]86-*-dicos*
1894 x86_64 DICOS x86_64-*-dicos*
1897 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1898 (mingw32ce) debugging.
1904 These commands were actually not implemented on any target.
1906 *** Changes in GDB 6.8
1908 * New native configurations
1910 NetBSD/hppa hppa*-*netbsd*
1911 Xtensa GNU/Linux xtensa*-*-linux*
1915 NetBSD/hppa hppa*-*-netbsd*
1916 Xtensa GNU/Lunux xtensa*-*-linux*
1918 * Change in command line behavior -- corefiles vs. process ids.
1920 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1921 attaching to process NUMBER fails, GDB no longer attempts to open a
1922 core file named NUMBER. Attaching to a program using the -c option
1923 is no longer supported. Instead, use the '-p' or '--pid' options.
1925 * GDB can now be built as a native debugger for debugging Windows x86
1926 (mingw32) Portable Executable (PE) programs.
1928 * Pending breakpoints no longer change their number when their address
1931 * GDB now supports breakpoints with multiple locations,
1932 including breakpoints on C++ constructors, inside C++ templates,
1933 and in inlined functions.
1935 * GDB's ability to debug optimized code has been improved. GDB more
1936 accurately identifies function bodies and lexical blocks that occupy
1937 more than one contiguous range of addresses.
1939 * Target descriptions can now describe registers for PowerPC.
1941 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1942 registers on PowerPC targets.
1944 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1945 targets even when the libthread_db library is not available.
1947 * The GDB remote stub, gdbserver, now supports the new file transfer
1948 commands (remote put, remote get, and remote delete).
1950 * The GDB remote stub, gdbserver, now supports run and attach in
1951 extended-remote mode.
1953 * hppa*64*-*-hpux11* target broken
1954 The debugger is unable to start a program and fails with the following
1955 error: "Error trying to get information about dynamic linker".
1956 The gdb-6.7 release is also affected.
1958 * GDB now supports the --enable-targets= configure option to allow
1959 building a single GDB executable that supports multiple remote
1960 target architectures.
1962 * GDB now supports debugging C and C++ programs which use the
1963 Decimal Floating Point extension. In addition, the PowerPC target
1964 now has a set of pseudo-registers to inspect decimal float values
1965 stored in two consecutive float registers.
1967 * The -break-insert MI command can optionally create pending
1970 * Improved support for debugging Ada
1971 Many improvements to the Ada language support have been made. These
1973 - Better support for Ada2005 interface types
1974 - Improved handling of arrays and slices in general
1975 - Better support for Taft-amendment types
1976 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1978 - Improved command completion in Ada
1981 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1986 set print frame-arguments (all|scalars|none)
1987 show print frame-arguments
1988 The value of this variable can be changed to control which argument
1989 values should be printed by the debugger when displaying a frame.
1994 Transfer files to and from a remote target, and delete remote files.
2001 Transfer files to and from a remote target, and delete remote files.
2003 * New remote packets
2010 Open, close, read, write, and delete files on the remote system.
2013 Attach to an existing process on the remote system, in extended-remote
2017 Run a new process on the remote system, in extended-remote mode.
2019 *** Changes in GDB 6.7
2021 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2022 bfd, libiberty and opcodes, as revealed by static analysis donated by
2023 Coverity, Inc. (http://scan.coverity.com).
2025 * When looking up multiply-defined global symbols, GDB will now prefer the
2026 symbol definition in the current shared library if it was built using the
2027 -Bsymbolic linker option.
2029 * When the Text User Interface (TUI) is not configured, GDB will now
2030 recognize the -tui command-line option and print a message that the TUI
2033 * The GDB remote stub, gdbserver, now has lower overhead for high
2034 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2036 * GDB for MIPS targets now autodetects whether a remote target provides
2037 32-bit or 64-bit register values.
2039 * Support for C++ member pointers has been improved.
2041 * GDB now understands XML target descriptions, which specify the
2042 target's overall architecture. GDB can read a description from
2043 a local file or over the remote serial protocol.
2045 * Vectors of single-byte data use a new integer type which is not
2046 automatically displayed as character or string data.
2048 * The /s format now works with the print command. It displays
2049 arrays of single-byte integers and pointers to single-byte integers
2052 * Target descriptions can now describe target-specific registers,
2053 for architectures which have implemented the support (currently
2054 only ARM, M68K, and MIPS).
2056 * GDB and the GDB remote stub, gdbserver, now support the XScale
2059 * The GDB remote stub, gdbserver, has been updated to support
2060 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2061 has been rewritten to use the standard GDB remote protocol.
2063 * GDB can now step into C++ functions which are called through thunks.
2065 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2067 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2068 layout. It also supports a TextSeg= and DataSeg= response when only
2069 segment base addresses (rather than offsets) are available.
2071 * The /i format now outputs any trailing branch delay slot instructions
2072 immediately following the last instruction within the count specified.
2074 * The GDB remote protocol "T" stop reply packet now supports a
2075 "library" response. Combined with the new "qXfer:libraries:read"
2076 packet, this response allows GDB to debug shared libraries on targets
2077 where the operating system manages the list of loaded libraries (e.g.
2078 Windows and SymbianOS).
2080 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2081 (DLLs) on Windows and Windows CE targets.
2083 * GDB now supports a faster verification that a .debug file matches its binary
2084 according to its build-id signature, if the signature is present.
2090 Enable or disable hardware flow control (RTS/CTS) on the serial port
2091 when debugging using remote targets.
2093 set mem inaccessible-by-default
2094 show mem inaccessible-by-default
2095 If the target supplies a memory map, for instance via the remote
2096 protocol's "qXfer:memory-map:read" packet, setting this variable
2097 prevents GDB from accessing memory outside the memory map. This
2098 is useful for targets with memory mapped registers or which react
2099 badly to accesses of unmapped address space.
2101 set breakpoint auto-hw
2102 show breakpoint auto-hw
2103 If the target supplies a memory map, for instance via the remote
2104 protocol's "qXfer:memory-map:read" packet, setting this variable
2105 lets GDB use hardware breakpoints automatically for memory regions
2106 where it can not use software breakpoints. This covers both the
2107 "break" command and internal breakpoints used for other commands
2108 including "next" and "finish".
2111 catch exception unhandled
2112 Stop the program execution when Ada exceptions are raised.
2115 Stop the program execution when an Ada assertion failed.
2119 Set an alternate system root for target files. This is a more
2120 general version of "set solib-absolute-prefix", which is now
2121 an alias to "set sysroot".
2124 Provide extended SPU facility status information. This set of
2125 commands is available only when debugging the Cell/B.E. SPU
2128 * New native configurations
2130 OpenBSD/sh sh*-*openbsd*
2133 unset tdesc filename
2135 Use the specified local file as an XML target description, and do
2136 not query the target for its built-in description.
2140 OpenBSD/sh sh*-*-openbsd*
2141 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2142 Toshiba Media Processor mep-elf
2144 * New remote packets
2147 Ignore the specified signals; pass them directly to the debugged program
2148 without stopping other threads or reporting them to GDB.
2150 qXfer:features:read:
2151 Read an XML target description from the target, which describes its
2156 Read or write contents of an spufs file on the target system. These
2157 packets are available only on the Cell/B.E. SPU architecture.
2159 qXfer:libraries:read:
2160 Report the loaded shared libraries. Combined with new "T" packet
2161 response, this packet allows GDB to debug shared libraries on
2162 targets where the operating system manages the list of loaded
2163 libraries (e.g. Windows and SymbianOS).
2167 Support for these obsolete configurations has been removed.
2175 i[34567]86-*-lynxos*
2176 i[34567]86-*-netware*
2177 i[34567]86-*-sco3.2v5*
2178 i[34567]86-*-sco3.2v4*
2180 i[34567]86-*-sysv4.2*
2183 i[34567]86-*-unixware2*
2184 i[34567]86-*-unixware*
2193 * Other removed features
2200 Various m68k-only ROM monitors.
2207 Various Renesas ROM monitors and debugging interfaces for SH and
2212 Support for a Macraigor serial interface to on-chip debugging.
2213 GDB does not directly support the newer parallel or USB
2218 A debug information format. The predecessor to DWARF 2 and
2219 DWARF 3, which are still supported.
2221 Support for the HP aCC compiler on HP-UX/PA-RISC
2223 SOM-encapsulated symbolic debugging information, automatic
2224 invocation of pxdb, and the aCC custom C++ ABI. This does not
2225 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2226 with aCC can still be debugged on an assembly level.
2228 MIPS ".pdr" sections
2230 A MIPS-specific format used to describe stack frame layout
2231 in debugging information.
2235 GDB could work with an older version of Guile to debug
2236 the interpreter and Scheme programs running in it.
2238 set mips stack-arg-size
2239 set mips saved-gpreg-size
2241 Use "set mips abi" to control parameter passing for MIPS.
2243 *** Changes in GDB 6.6
2248 Cell Broadband Engine SPU spu-elf
2250 * GDB can now be configured as a cross-debugger targeting native Windows
2251 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2252 running on a Windows system over TCP/IP to debug Windows programs.
2254 * The GDB remote stub, gdbserver, has been updated to support Windows and
2255 Cygwin debugging. Both single-threaded and multi-threaded programs are
2258 * The "set trust-readonly-sections" command works again. This command was
2259 broken in GDB 6.3, 6.4, and 6.5.
2261 * The "load" command now supports writing to flash memory, if the remote
2262 stub provides the required support.
2264 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2265 longer requires symbolic debug information (e.g. DWARF-2).
2270 unset substitute-path
2271 show substitute-path
2272 Manage a list of substitution rules that GDB uses to rewrite the name
2273 of the directories where the sources are located. This can be useful
2274 for instance when the sources were moved to a different location
2275 between compilation and debugging.
2279 Print each CLI command as it is executed. Each command is prefixed with
2280 a number of `+' symbols representing the nesting depth.
2281 The source command now has a `-v' option to enable the same feature.
2285 The ARM Demon monitor support (RDP protocol, "target rdp").
2287 Kernel Object Display, an embedded debugging feature which only worked with
2288 an obsolete version of Cisco IOS.
2290 The 'set download-write-size' and 'show download-write-size' commands.
2292 * New remote packets
2295 Tell a stub about GDB client features, and request remote target features.
2296 The first feature implemented is PacketSize, which allows the target to
2297 specify the size of packets it can handle - to minimize the number of
2298 packets required and improve performance when connected to a remote
2302 Fetch an OS auxilliary vector from the remote stub. This packet is a
2303 more efficient replacement for qPart:auxv:read.
2305 qXfer:memory-map:read:
2306 Fetch a memory map from the remote stub, including information about
2307 RAM, ROM, and flash memory devices.
2312 Erase and program a flash memory device.
2314 * Removed remote packets
2317 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2318 used it, and only gdbserver implemented it.
2320 *** Changes in GDB 6.5
2324 Renesas M32C/M16C m32c-elf
2326 Morpho Technologies ms1 ms1-elf
2330 init-if-undefined Initialize a convenience variable, but
2331 only if it doesn't already have a value.
2333 The following commands are presently only implemented for native GNU/Linux:
2335 checkpoint Save a snapshot of the program state.
2337 restart <n> Return the program state to a
2338 previously saved state.
2340 info checkpoints List currently saved checkpoints.
2342 delete-checkpoint <n> Delete a previously saved checkpoint.
2344 set|show detach-on-fork Tell gdb whether to detach from a newly
2345 forked process, or to keep debugging it.
2347 info forks List forks of the user program that
2348 are available to be debugged.
2350 fork <n> Switch to debugging one of several
2351 forks of the user program that are
2352 available to be debugged.
2354 delete-fork <n> Delete a fork from the list of forks
2355 that are available to be debugged (and
2356 kill the forked process).
2358 detach-fork <n> Delete a fork from the list of forks
2359 that are available to be debugged (and
2360 allow the process to continue).
2364 Morpho Technologies ms2 ms1-elf
2366 * Improved Windows host support
2368 GDB now builds as a cross debugger hosted on i686-mingw32, including
2369 native console support, and remote communications using either
2370 network sockets or serial ports.
2372 * Improved Modula-2 language support
2374 GDB can now print most types in the Modula-2 syntax. This includes:
2375 basic types, set types, record types, enumerated types, range types,
2376 pointer types and ARRAY types. Procedure var parameters are correctly
2377 printed and hexadecimal addresses and character constants are also
2378 written in the Modula-2 syntax. Best results can be obtained by using
2379 GNU Modula-2 together with the -gdwarf-2 command line option.
2383 The ARM rdi-share module.
2385 The Netware NLM debug server.
2387 *** Changes in GDB 6.4
2389 * New native configurations
2391 OpenBSD/arm arm*-*-openbsd*
2392 OpenBSD/mips64 mips64-*-openbsd*
2396 Morpho Technologies ms1 ms1-elf
2398 * New command line options
2400 --batch-silent As for --batch, but totally silent.
2401 --return-child-result The debugger will exist with the same value
2402 the child (debugged) program exited with.
2403 --eval-command COMMAND, -ex COMMAND
2404 Execute a single GDB CLI command. This may be
2405 specified multiple times and in conjunction
2406 with the --command (-x) option.
2408 * Deprecated commands removed
2410 The following commands, that were deprecated in 2000, have been
2414 set|show arm disassembly-flavor set|show arm disassembler
2415 othernames set arm disassembler
2416 set|show remotedebug set|show debug remote
2417 set|show archdebug set|show debug arch
2418 set|show eventdebug set|show debug event
2421 * New BSD user-level threads support
2423 It is now possible to debug programs using the user-level threads
2424 library on OpenBSD and FreeBSD. Currently supported (target)
2427 FreeBSD/amd64 x86_64-*-freebsd*
2428 FreeBSD/i386 i386-*-freebsd*
2429 OpenBSD/i386 i386-*-openbsd*
2431 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2432 are not yet supported.
2434 * New support for Matsushita MN10300 w/sim added
2435 (Work in progress). mn10300-elf.
2437 * REMOVED configurations and files
2439 VxWorks and the XDR protocol *-*-vxworks
2440 Motorola MCORE mcore-*-*
2441 National Semiconductor NS32000 ns32k-*-*
2443 * New "set print array-indexes" command
2445 After turning this setting "on", GDB prints the index of each element
2446 when displaying arrays. The default is "off" to preserve the previous
2449 * VAX floating point support
2451 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2453 * User-defined command support
2455 In addition to using $arg0..$arg9 for argument passing, it is now possible
2456 to use $argc to determine now many arguments have been passed. See the
2457 section on user-defined commands in the user manual for more information.
2459 *** Changes in GDB 6.3:
2461 * New command line option
2463 GDB now accepts -l followed by a number to set the timeout for remote
2466 * GDB works with GCC -feliminate-dwarf2-dups
2468 GDB now supports a more compact representation of DWARF-2 debug
2469 information using DW_FORM_ref_addr references. These are produced
2470 by GCC with the option -feliminate-dwarf2-dups and also by some
2471 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2472 to use -feliminate-dwarf2-dups.
2474 * Internationalization
2476 When supported by the host system, GDB will be built with
2477 internationalization (libintl). The task of marking up the sources is
2478 continued, we're looking forward to our first translation.
2482 Initial support for debugging programs compiled with the GNAT
2483 implementation of the Ada programming language has been integrated
2484 into GDB. In this release, support is limited to expression evaluation.
2486 * New native configurations
2488 GNU/Linux/m32r m32r-*-linux-gnu
2492 GDB's remote protocol now includes support for the 'p' packet. This
2493 packet is used to fetch individual registers from a remote inferior.
2495 * END-OF-LIFE registers[] compatibility module
2497 GDB's internal register infrastructure has been completely rewritten.
2498 The new infrastructure making possible the implementation of key new
2499 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2502 GDB 6.3 will be the last release to include the the registers[]
2503 compatibility module that allowed out-of-date configurations to
2504 continue to work. This change directly impacts the following
2514 powerpc bdm protocol
2516 Unless there is activity to revive these configurations, they will be
2517 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2519 * OBSOLETE configurations and files
2521 Configurations that have been declared obsolete in this release have
2522 been commented out. Unless there is activity to revive these
2523 configurations, the next release of GDB will have their sources
2524 permanently REMOVED.
2533 *** Changes in GDB 6.2.1:
2535 * MIPS `break main; run' gave an heuristic-fence-post warning
2537 When attempting to run even a simple program, a warning about
2538 heuristic-fence-post being hit would be reported. This problem has
2541 * MIPS IRIX 'long double' crashed GDB
2543 When examining a long double variable, GDB would get a segmentation
2544 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2545 IRIX long double values).
2549 A bug in the VAX stack code was causing problems with the "next"
2550 command. This problem has been fixed.
2552 *** Changes in GDB 6.2:
2554 * Fix for ``many threads''
2556 On GNU/Linux systems that use the NPTL threads library, a program
2557 rapidly creating and deleting threads would confuse GDB leading to the
2560 ptrace: No such process.
2561 thread_db_get_info: cannot get thread info: generic error
2563 This problem has been fixed.
2565 * "-async" and "-noasync" options removed.
2567 Support for the broken "-noasync" option has been removed (it caused
2570 * New ``start'' command.
2572 This command runs the program until the begining of the main procedure.
2574 * New BSD Kernel Data Access Library (libkvm) interface
2576 Using ``target kvm'' it is now possible to debug kernel core dumps and
2577 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2578 platforms. Currently supported (native-only) configurations are:
2580 FreeBSD/amd64 x86_64-*-freebsd*
2581 FreeBSD/i386 i?86-*-freebsd*
2582 NetBSD/i386 i?86-*-netbsd*
2583 NetBSD/m68k m68*-*-netbsd*
2584 NetBSD/sparc sparc-*-netbsd*
2585 OpenBSD/amd64 x86_64-*-openbsd*
2586 OpenBSD/i386 i?86-*-openbsd*
2587 OpenBSD/m68k m68*-openbsd*
2588 OpenBSD/sparc sparc-*-openbsd*
2590 * Signal trampoline code overhauled
2592 Many generic problems with GDB's signal handling code have been fixed.
2593 These include: backtraces through non-contiguous stacks; recognition
2594 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2595 call; backtrace through a signal trampoline; step into and out of
2596 signal handlers; and single-stepping in the signal trampoline.
2598 Please note that kernel bugs are a limiting factor here. These
2599 features have been shown to work on an s390 GNU/Linux system that
2600 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2602 * Cygwin support for DWARF 2 added.
2604 * New native configurations
2606 GNU/Linux/hppa hppa*-*-linux*
2607 OpenBSD/hppa hppa*-*-openbsd*
2608 OpenBSD/m68k m68*-*-openbsd*
2609 OpenBSD/m88k m88*-*-openbsd*
2610 OpenBSD/powerpc powerpc-*-openbsd*
2611 NetBSD/vax vax-*-netbsd*
2612 OpenBSD/vax vax-*-openbsd*
2614 * END-OF-LIFE frame compatibility module
2616 GDB's internal frame infrastructure has been completely rewritten.
2617 The new infrastructure making it possible to support key new features
2618 including DWARF 2 Call Frame Information. To aid in the task of
2619 migrating old configurations to this new infrastructure, a
2620 compatibility module, that allowed old configurations to continue to
2621 work, was also included.
2623 GDB 6.2 will be the last release to include this frame compatibility
2624 module. This change directly impacts the following configurations:
2634 Unless there is activity to revive these configurations, they will be
2635 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2637 * REMOVED configurations and files
2639 Sun 3, running SunOS 3 m68*-*-sunos3*
2640 Sun 3, running SunOS 4 m68*-*-sunos4*
2641 Sun 2, running SunOS 3 m68000-*-sunos3*
2642 Sun 2, running SunOS 4 m68000-*-sunos4*
2643 Motorola 680x0 running LynxOS m68*-*-lynxos*
2644 AT&T 3b1/Unix pc m68*-att-*
2645 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2646 decstation mips-dec-* mips-little-*
2647 riscos mips-*-riscos* mips-*-sysv*
2648 sonymips mips-sony-*
2649 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2651 *** Changes in GDB 6.1.1:
2653 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2655 The TUI (Text-mode User Interface) is now built as part of a default
2656 GDB configuration. It is enabled by either selecting the TUI with the
2657 command line option "-i=tui" or by running the separate "gdbtui"
2658 program. For more information on the TUI, see the manual "Debugging
2661 * Pending breakpoint support (also included in GDB 6.1)
2663 Support has been added to allow you to specify breakpoints in shared
2664 libraries that have not yet been loaded. If a breakpoint location
2665 cannot be found, and the "breakpoint pending" option is set to auto,
2666 GDB queries you if you wish to make the breakpoint pending on a future
2667 shared-library load. If and when GDB resolves the breakpoint symbol,
2668 the pending breakpoint is removed as one or more regular breakpoints
2671 Pending breakpoints are very useful for GCJ Java debugging.
2673 * Fixed ISO-C build problems
2675 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2676 non ISO-C code that stopped them being built using a more strict ISO-C
2677 compiler (e.g., IBM's C compiler).
2679 * Fixed build problem on IRIX 5
2681 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2682 wasn't able to compile compile on an IRIX 5 system.
2684 * Added execute permission to gdb/gdbserver/configure
2686 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2687 permission. This bug would cause configure to fail on a number of
2688 systems (Solaris, IRIX). Ref: server/519.
2690 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2692 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2693 has been updated to use constant array sizes.
2695 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2697 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2698 its generated DWARF Call Frame Info. This encoding was causing GDB to
2699 panic, that panic has been fixed. Ref: gdb/1628.
2701 * Fixed a problem when examining parameters in shared library code.
2703 When examining parameters in optimized shared library code generated
2704 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2705 not available''. GDB now correctly displays the variable's value.
2707 *** Changes in GDB 6.1:
2709 * Removed --with-mmalloc
2711 Support for the mmalloc memory manager has been removed, as it
2712 conflicted with the internal gdb byte cache.
2714 * Changes in AMD64 configurations
2716 The AMD64 target now includes the %cs and %ss registers. As a result
2717 the AMD64 remote protocol has changed; this affects the floating-point
2718 and SSE registers. If you rely on those registers for your debugging,
2719 you should upgrade gdbserver on the remote side.
2721 * Revised SPARC target
2723 The SPARC target has been completely revised, incorporating the
2724 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2725 support for LynxOS and SunOS 4 has been dropped. Calling functions
2726 from within GDB on operating systems with a non-executable stack
2727 (Solaris, OpenBSD) now works.
2731 GDB has a new C++ demangler which does a better job on the mangled
2732 names generated by current versions of g++. It also runs faster, so
2733 with this and other changes gdb should now start faster on large C++
2736 * DWARF 2 Location Expressions
2738 GDB support for location expressions has been extended to support function
2739 arguments and frame bases. Older versions of GDB could crash when they
2742 * C++ nested types and namespaces
2744 GDB's support for nested types and namespaces in C++ has been
2745 improved, especially if you use the DWARF 2 debugging format. (This
2746 is the default for recent versions of GCC on most platforms.)
2747 Specifically, if you have a class "Inner" defined within a class or
2748 namespace "Outer", then GDB realizes that the class's name is
2749 "Outer::Inner", not simply "Inner". This should greatly reduce the
2750 frequency of complaints about not finding RTTI symbols. In addition,
2751 if you are stopped at inside of a function defined within a namespace,
2752 GDB modifies its name lookup accordingly.
2754 * New native configurations
2756 NetBSD/amd64 x86_64-*-netbsd*
2757 OpenBSD/amd64 x86_64-*-openbsd*
2758 OpenBSD/alpha alpha*-*-openbsd*
2759 OpenBSD/sparc sparc-*-openbsd*
2760 OpenBSD/sparc64 sparc64-*-openbsd*
2762 * New debugging protocols
2764 M32R with SDI protocol m32r-*-elf*
2766 * "set prompt-escape-char" command deleted.
2768 The command "set prompt-escape-char" has been deleted. This command,
2769 and its very obscure effet on GDB's prompt, was never documented,
2770 tested, nor mentioned in the NEWS file.
2772 * OBSOLETE configurations and files
2774 Configurations that have been declared obsolete in this release have
2775 been commented out. Unless there is activity to revive these
2776 configurations, the next release of GDB will have their sources
2777 permanently REMOVED.
2779 Sun 3, running SunOS 3 m68*-*-sunos3*
2780 Sun 3, running SunOS 4 m68*-*-sunos4*
2781 Sun 2, running SunOS 3 m68000-*-sunos3*
2782 Sun 2, running SunOS 4 m68000-*-sunos4*
2783 Motorola 680x0 running LynxOS m68*-*-lynxos*
2784 AT&T 3b1/Unix pc m68*-att-*
2785 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2786 decstation mips-dec-* mips-little-*
2787 riscos mips-*-riscos* mips-*-sysv*
2788 sonymips mips-sony-*
2789 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2791 * REMOVED configurations and files
2793 SGI Irix-4.x mips-sgi-irix4 or iris4
2794 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2795 Z8000 simulator z8k-zilog-none or z8ksim
2796 Matsushita MN10200 w/simulator mn10200-*-*
2797 H8/500 simulator h8500-hitachi-hms or h8500hms
2798 HP/PA running BSD hppa*-*-bsd*
2799 HP/PA running OSF/1 hppa*-*-osf*
2800 HP/PA Pro target hppa*-*-pro*
2801 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2802 386BSD i[3456]86-*-bsd*
2803 Sequent family i[3456]86-sequent-sysv4*
2804 i[3456]86-sequent-sysv*
2805 i[3456]86-sequent-bsd*
2806 SPARC running LynxOS sparc-*-lynxos*
2807 SPARC running SunOS 4 sparc-*-sunos4*
2808 Tsqware Sparclet sparclet-*-*
2809 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2811 *** Changes in GDB 6.0:
2815 Support for debugging the Objective-C programming language has been
2816 integrated into GDB.
2818 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2820 DWARF 2's Call Frame Information makes available compiler generated
2821 information that more exactly describes the program's run-time stack.
2822 By using this information, GDB is able to provide more robust stack
2825 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2826 have been updated to use a new backtrace mechanism which includes
2827 DWARF 2 CFI support.
2831 GDB's remote protocol has been extended to include support for hosted
2832 file I/O (where the remote target uses GDB's file system). See GDB's
2833 remote protocol documentation for details.
2835 * All targets using the new architecture framework.
2837 All of GDB's targets have been updated to use the new internal
2838 architecture framework. The way is now open for future GDB releases
2839 to include cross-architecture native debugging support (i386 on amd64,
2842 * GNU/Linux's Thread Local Storage (TLS)
2844 GDB now includes support for for the GNU/Linux implementation of
2845 per-thread variables.
2847 * GNU/Linux's Native POSIX Thread Library (NPTL)
2849 GDB's thread code has been updated to work with either the new
2850 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2852 * Separate debug info.
2854 GDB, in conjunction with BINUTILS, now supports a mechanism for
2855 automatically loading debug information from a separate file. Instead
2856 of shipping full debug and non-debug versions of system libraries,
2857 system integrators can now instead ship just the stripped libraries
2858 and optional debug files.
2860 * DWARF 2 Location Expressions
2862 DWARF 2 Location Expressions allow the compiler to more completely
2863 describe the location of variables (even in optimized code) to the
2866 GDB now includes preliminary support for location expressions (support
2867 for DW_OP_piece is still missing).
2871 A number of long standing bugs that caused GDB to die while starting a
2872 Java application have been fixed. GDB's Java support is now
2873 considered "useable".
2875 * GNU/Linux support for fork, vfork, and exec.
2877 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2878 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2881 * GDB supports logging output to a file
2883 There are two new commands, "set logging" and "show logging", which can be
2884 used to capture GDB's output to a file.
2886 * The meaning of "detach" has changed for gdbserver
2888 The "detach" command will now resume the application, as documented. To
2889 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2892 * d10v, m68hc11 `regs' command deprecated
2894 The `info registers' command has been updated so that it displays the
2895 registers using a format identical to the old `regs' command.
2899 A new command, "maint set profile on/off", has been added. This command can
2900 be used to enable or disable profiling while running GDB, to profile a
2901 session or a set of commands. In addition there is a new configure switch,
2902 "--enable-profiling", which will cause GDB to be compiled with profiling
2903 data, for more informative profiling results.
2905 * Default MI syntax changed to "mi2".
2907 The default MI (machine interface) syntax, enabled by the command line
2908 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2909 "mi1", can be enabled by specifying the option "-i=mi1".
2911 Support for the original "mi0" syntax (included in GDB 5.0) has been
2914 Fix for gdb/192: removed extraneous space when displaying frame level.
2915 Fix for gdb/672: update changelist is now output in mi list format.
2916 Fix for gdb/702: a -var-assign that updates the value now shows up
2917 in a subsequent -var-update.
2919 * New native configurations.
2921 FreeBSD/amd64 x86_64-*-freebsd*
2923 * Multi-arched targets.
2925 HP/PA HPUX11 hppa*-*-hpux*
2926 Renesas M32R/D w/simulator m32r-*-elf*
2928 * OBSOLETE configurations and files
2930 Configurations that have been declared obsolete in this release have
2931 been commented out. Unless there is activity to revive these
2932 configurations, the next release of GDB will have their sources
2933 permanently REMOVED.
2935 Z8000 simulator z8k-zilog-none or z8ksim
2936 Matsushita MN10200 w/simulator mn10200-*-*
2937 H8/500 simulator h8500-hitachi-hms or h8500hms
2938 HP/PA running BSD hppa*-*-bsd*
2939 HP/PA running OSF/1 hppa*-*-osf*
2940 HP/PA Pro target hppa*-*-pro*
2941 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2942 Sequent family i[3456]86-sequent-sysv4*
2943 i[3456]86-sequent-sysv*
2944 i[3456]86-sequent-bsd*
2945 Tsqware Sparclet sparclet-*-*
2946 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2948 * REMOVED configurations and files
2951 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2952 IBM AIX PS/2 i[3456]86-*-aix
2953 i386 running Mach 3.0 i[3456]86-*-mach3*
2954 i386 running Mach i[3456]86-*-mach*
2955 i386 running OSF/1 i[3456]86-*osf1mk*
2956 HP/Apollo 68k Family m68*-apollo*-sysv*,
2958 m68*-hp-bsd*, m68*-hp-hpux*
2959 Argonaut Risc Chip (ARC) arc-*-*
2960 Mitsubishi D30V d30v-*-*
2961 Fujitsu FR30 fr30-*-elf*
2962 OS/9000 i[34]86-*-os9k
2963 I960 with MON960 i960-*-coff
2965 * MIPS $fp behavior changed
2967 The convenience variable $fp, for the MIPS, now consistently returns
2968 the address of the current frame's base. Previously, depending on the
2969 context, $fp could refer to either $sp or the current frame's base
2970 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2971 The GNU Source-Level Debugger''.
2973 *** Changes in GDB 5.3:
2975 * GNU/Linux shared library multi-threaded performance improved.
2977 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2978 `/proc', in preference to `ptrace' for memory reads. This may result
2979 in an improvement in the start-up time of multi-threaded, shared
2980 library applications when run under GDB. One GDB user writes: ``loads
2981 shared libs like mad''.
2983 * ``gdbserver'' now supports multi-threaded applications on some targets
2985 Support for debugging multi-threaded applications which use
2986 the GNU/Linux LinuxThreads package has been added for
2987 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2988 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2990 * GDB now supports C/C++ preprocessor macros.
2992 GDB now expands preprocessor macro invocations in C/C++ expressions,
2993 and provides various commands for showing macro definitions and how
2996 The new command `macro expand EXPRESSION' expands any macro
2997 invocations in expression, and shows the result.
2999 The new command `show macro MACRO-NAME' shows the definition of the
3000 macro named MACRO-NAME, and where it was defined.
3002 Most compilers don't include information about macros in the debugging
3003 information by default. In GCC 3.1, for example, you need to compile
3004 your program with the options `-gdwarf-2 -g3'. If the macro
3005 information is present in the executable, GDB will read it.
3007 * Multi-arched targets.
3009 DEC Alpha (partial) alpha*-*-*
3010 DEC VAX (partial) vax-*-*
3012 National Semiconductor NS32000 (partial) ns32k-*-*
3013 Motorola 68000 (partial) m68k-*-*
3014 Motorola MCORE mcore-*-*
3018 Fujitsu FRV architecture added by Red Hat frv*-*-*
3021 * New native configurations
3023 Alpha NetBSD alpha*-*-netbsd*
3024 SH NetBSD sh*-*-netbsdelf*
3025 MIPS NetBSD mips*-*-netbsd*
3026 UltraSPARC NetBSD sparc64-*-netbsd*
3028 * OBSOLETE configurations and files
3030 Configurations that have been declared obsolete in this release have
3031 been commented out. Unless there is activity to revive these
3032 configurations, the next release of GDB will have their sources
3033 permanently REMOVED.
3035 Mitsubishi D30V d30v-*-*
3036 OS/9000 i[34]86-*-os9k
3037 IBM AIX PS/2 i[3456]86-*-aix
3038 Fujitsu FR30 fr30-*-elf*
3039 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3040 Argonaut Risc Chip (ARC) arc-*-*
3041 i386 running Mach 3.0 i[3456]86-*-mach3*
3042 i386 running Mach i[3456]86-*-mach*
3043 i386 running OSF/1 i[3456]86-*osf1mk*
3044 HP/Apollo 68k Family m68*-apollo*-sysv*,
3046 m68*-hp-bsd*, m68*-hp-hpux*
3047 I960 with MON960 i960-*-coff
3049 * OBSOLETE languages
3051 CHILL, a Pascal like language used by telecommunications companies.
3053 * REMOVED configurations and files
3055 AMD 29k family via UDI a29k-amd-udi, udi29k
3056 A29K VxWorks a29k-*-vxworks
3057 AMD 29000 embedded, using EBMON a29k-none-none
3058 AMD 29000 embedded with COFF a29k-none-coff
3059 AMD 29000 embedded with a.out a29k-none-aout
3061 testsuite/gdb.hp/gdb.threads-hp/ directory
3063 * New command "set max-user-call-depth <nnn>"
3065 This command allows the user to limit the call depth of user-defined
3066 commands. The default is 1024.
3068 * Changes in FreeBSD/i386 native debugging.
3070 Support for the "generate-core-file" has been added.
3072 * New commands "dump", "append", and "restore".
3074 These commands allow data to be copied from target memory
3075 to a bfd-format or binary file (dump and append), and back
3076 from a file into memory (restore).
3078 * Improved "next/step" support on multi-processor Alpha Tru64.
3080 The previous single-step mechanism could cause unpredictable problems,
3081 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3082 of a software single-step mechanism prevents this.
3084 *** Changes in GDB 5.2.1:
3092 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3093 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3094 Fix, by Joel Brobecker imported from mainline.
3096 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3097 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3098 Fix, by Fred Fish, imported from mainline.
3100 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3101 Surprisingly enough, it works now.
3102 By Michal Ludvig, imported from mainline.
3104 i386 hardware watchpoint support:
3105 avoid misses on second run for some targets.
3106 By Pierre Muller, imported from mainline.
3108 *** Changes in GDB 5.2:
3110 * New command "set trust-readonly-sections on[off]".
3112 This command is a hint that tells gdb that read-only sections
3113 really are read-only (ie. that their contents will not change).
3114 In this mode, gdb will go to the object file rather than the
3115 target to read memory from read-only sections (such as ".text").
3116 This can be a significant performance improvement on some
3117 (notably embedded) targets.
3119 * New command "generate-core-file" (or "gcore").
3121 This new gdb command allows the user to drop a core file of the child
3122 process state at any time. So far it's been implemented only for
3123 GNU/Linux and Solaris, but should be relatively easily ported to other
3124 hosts. Argument is core file name (defaults to core.<pid>).
3126 * New command line option
3128 GDB now accepts --pid or -p followed by a process id.
3130 * Change in command line behavior -- corefiles vs. process ids.
3132 There is a subtle behavior in the way in which GDB handles
3133 command line arguments. The first non-flag argument is always
3134 a program to debug, but the second non-flag argument may either
3135 be a corefile or a process id. Previously, GDB would attempt to
3136 open the second argument as a corefile, and if that failed, would
3137 issue a superfluous error message and then attempt to attach it as
3138 a process. Now, if the second argument begins with a non-digit,
3139 it will be treated as a corefile. If it begins with a digit,
3140 GDB will attempt to attach it as a process, and if no such process
3141 is found, will then attempt to open it as a corefile.
3143 * Changes in ARM configurations.
3145 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3146 configuration is fully multi-arch.
3148 * New native configurations
3150 ARM NetBSD arm*-*-netbsd*
3151 x86 OpenBSD i[3456]86-*-openbsd*
3152 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3153 Sparc64 running FreeBSD sparc64-*-freebsd*
3157 Sanyo XStormy16 xstormy16-elf
3159 * OBSOLETE configurations and files
3161 Configurations that have been declared obsolete in this release have
3162 been commented out. Unless there is activity to revive these
3163 configurations, the next release of GDB will have their sources
3164 permanently REMOVED.
3166 AMD 29k family via UDI a29k-amd-udi, udi29k
3167 A29K VxWorks a29k-*-vxworks
3168 AMD 29000 embedded, using EBMON a29k-none-none
3169 AMD 29000 embedded with COFF a29k-none-coff
3170 AMD 29000 embedded with a.out a29k-none-aout
3172 testsuite/gdb.hp/gdb.threads-hp/ directory
3174 * REMOVED configurations and files
3176 TI TMS320C80 tic80-*-*
3178 PowerPC Solaris powerpcle-*-solaris*
3179 PowerPC Windows NT powerpcle-*-cygwin32
3180 PowerPC Netware powerpc-*-netware*
3181 Harris/CXUX m88k m88*-harris-cxux*
3182 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3183 ns32k-utek-sysv* ns32k-utek-*
3184 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3185 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3186 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3187 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3188 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3190 * Changes to command line processing
3192 The new `--args' feature can be used to specify command-line arguments
3193 for the inferior from gdb's command line.
3195 * Changes to key bindings
3197 There is a new `operate-and-get-next' function bound to `C-o'.
3199 *** Changes in GDB 5.1.1
3201 Fix compile problem on DJGPP.
3203 Fix a problem with floating-point registers on the i386 being
3206 Fix to stop GDB crashing on .debug_str debug info.
3208 Numerous documentation fixes.
3210 Numerous testsuite fixes.
3212 *** Changes in GDB 5.1:
3214 * New native configurations
3216 Alpha FreeBSD alpha*-*-freebsd*
3217 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3218 MIPS GNU/Linux mips*-*-linux*
3219 MIPS SGI Irix 6.x mips*-sgi-irix6*
3220 ia64 AIX ia64-*-aix*
3221 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3225 Motorola 68HC11 and 68HC12 m68hc11-elf
3227 UltraSparc running GNU/Linux sparc64-*-linux*
3229 * OBSOLETE configurations and files
3231 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3232 Harris/CXUX m88k m88*-harris-cxux*
3233 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3234 ns32k-utek-sysv* ns32k-utek-*
3235 TI TMS320C80 tic80-*-*
3237 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3238 PowerPC Solaris powerpcle-*-solaris*
3239 PowerPC Windows NT powerpcle-*-cygwin32
3240 PowerPC Netware powerpc-*-netware*
3241 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3242 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3243 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3244 Apple Macintosh (MPW) host N/A
3246 stuff.c (Program to stuff files into a specially prepared space in kdb)
3247 kdb-start.c (Main loop for the standalone kernel debugger)
3249 Configurations that have been declared obsolete in this release have
3250 been commented out. Unless there is activity to revive these
3251 configurations, the next release of GDB will have their sources
3252 permanently REMOVED.
3254 * REMOVED configurations and files
3256 Altos 3068 m68*-altos-*
3257 Convex c1-*-*, c2-*-*
3259 ARM RISCix arm-*-* (as host)
3263 * GDB has been converted to ISO C.
3265 GDB's source code has been converted to ISO C. In particular, the
3266 sources are fully protoized, and rely on standard headers being
3271 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3273 * The MI enabled by default.
3275 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3276 revised and enabled by default. Packages which use GDB as a debugging
3277 engine behind a UI or another front end are encouraged to switch to
3278 using the GDB/MI interface, instead of the old annotations interface
3279 which is now deprecated.
3281 * Support for debugging Pascal programs.
3283 GDB now includes support for debugging Pascal programs. The following
3284 main features are supported:
3286 - Pascal-specific data types such as sets;
3288 - automatic recognition of Pascal sources based on file-name
3291 - Pascal-style display of data types, variables, and functions;
3293 - a Pascal expression parser.
3295 However, some important features are not yet supported.
3297 - Pascal string operations are not supported at all;
3299 - there are some problems with boolean types;
3301 - Pascal type hexadecimal constants are not supported
3302 because they conflict with the internal variables format;
3304 - support for Pascal objects and classes is not full yet;
3306 - unlike Pascal, GDB is case-sensitive for symbol names.
3308 * Changes in completion.
3310 Commands such as `shell', `run' and `set args', which pass arguments
3311 to inferior programs, now complete on file names, similar to what
3312 users expect at the shell prompt.
3314 Commands which accept locations, such as `disassemble', `print',
3315 `breakpoint', `until', etc. now complete on filenames as well as
3316 program symbols. Thus, if you type "break foob TAB", and the source
3317 files linked into the programs include `foobar.c', that file name will
3318 be one of the candidates for completion. However, file names are not
3319 considered for completion after you typed a colon that delimits a file
3320 name from a name of a function in that file, as in "break foo.c:bar".
3322 `set demangle-style' completes on available demangling styles.
3324 * New platform-independent commands:
3326 It is now possible to define a post-hook for a command as well as a
3327 hook that runs before the command. For more details, see the
3328 documentation of `hookpost' in the GDB manual.
3330 * Changes in GNU/Linux native debugging.
3332 Support for debugging multi-threaded programs has been completely
3333 revised for all platforms except m68k and sparc. You can now debug as
3334 many threads as your system allows you to have.
3336 Attach/detach is supported for multi-threaded programs.
3338 Support for SSE registers was added for x86. This doesn't work for
3339 multi-threaded programs though.
3341 * Changes in MIPS configurations.
3343 Multi-arch support is enabled for all MIPS configurations.
3345 GDB can now be built as native debugger on SGI Irix 6.x systems for
3346 debugging n32 executables. (Debugging 64-bit executables is not yet
3349 * Unified support for hardware watchpoints in all x86 configurations.
3351 Most (if not all) native x86 configurations support hardware-assisted
3352 breakpoints and watchpoints in a unified manner. This support
3353 implements debug register sharing between watchpoints, which allows to
3354 put a virtually infinite number of watchpoints on the same address,
3355 and also supports watching regions up to 16 bytes with several debug
3358 The new maintenance command `maintenance show-debug-regs' toggles
3359 debugging print-outs in functions that insert, remove, and test
3360 watchpoints and hardware breakpoints.
3362 * Changes in the DJGPP native configuration.
3364 New command ``info dos sysinfo'' displays assorted information about
3365 the CPU, OS, memory, and DPMI server.
3367 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3368 display information about segment descriptors stored in GDT, LDT, and
3371 New commands ``info dos pde'' and ``info dos pte'' display entries
3372 from Page Directory and Page Tables (for now works with CWSDPMI only).
3373 New command ``info dos address-pte'' displays the Page Table entry for
3374 a given linear address.
3376 GDB can now pass command lines longer than 126 characters to the
3377 program being debugged (requires an update to the libdbg.a library
3378 which is part of the DJGPP development kit).
3380 DWARF2 debug info is now supported.
3382 It is now possible to `step' and `next' through calls to `longjmp'.
3384 * Changes in documentation.
3386 All GDB documentation was converted to GFDL, the GNU Free
3387 Documentation License.
3389 Tracepoints-related commands are now fully documented in the GDB
3392 TUI, the Text-mode User Interface, is now documented in the manual.
3394 Tracepoints-related commands are now fully documented in the GDB
3397 The "GDB Internals" manual now has an index. It also includes
3398 documentation of `ui_out' functions, GDB coding standards, x86
3399 hardware watchpoints, and memory region attributes.
3401 * GDB's version number moved to ``version.in''
3403 The Makefile variable VERSION has been replaced by the file
3404 ``version.in''. People creating GDB distributions should update the
3405 contents of this file.
3409 GUD support is now a standard part of the EMACS distribution.
3411 *** Changes in GDB 5.0:
3413 * Improved support for debugging FP programs on x86 targets
3415 Unified and much-improved support for debugging floating-point
3416 programs on all x86 targets. In particular, ``info float'' now
3417 displays the FP registers in the same format on all x86 targets, with
3418 greater level of detail.
3420 * Improvements and bugfixes in hardware-assisted watchpoints
3422 It is now possible to watch array elements, struct members, and
3423 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3424 on x86 targets no longer erroneously trigger when the address is
3427 * Improvements in the native DJGPP version of GDB
3429 The distribution now includes all the scripts and auxiliary files
3430 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3431 machines ``out of the box''.
3433 The DJGPP version can now debug programs that use signals. It is
3434 possible to catch signals that happened in the debuggee, deliver
3435 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3436 would kill the program being debugged.) Programs that hook hardware
3437 interrupts (keyboard, timer, etc.) can also be debugged.
3439 It is now possible to debug DJGPP programs that redirect their
3440 standard handles or switch them to raw (as opposed to cooked) mode, or
3441 even close them. The command ``run < foo > bar'' works as expected,
3442 and ``info terminal'' reports useful information about the debuggee's
3443 terminal, including raw/cooked mode, redirection, etc.
3445 The DJGPP version now uses termios functions for console I/O, which
3446 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3449 DOS-style file names with drive letters are now fully supported by
3452 It is now possible to debug DJGPP programs that switch their working
3453 directory. It is also possible to rerun the debuggee any number of
3454 times without restarting GDB; thus, you can use the same setup,
3455 breakpoints, etc. for many debugging sessions.
3457 * New native configurations
3459 ARM GNU/Linux arm*-*-linux*
3460 PowerPC GNU/Linux powerpc-*-linux*
3464 Motorola MCore mcore-*-*
3465 x86 VxWorks i[3456]86-*-vxworks*
3466 PowerPC VxWorks powerpc-*-vxworks*
3467 TI TMS320C80 tic80-*-*
3469 * OBSOLETE configurations
3471 Altos 3068 m68*-altos-*
3472 Convex c1-*-*, c2-*-*
3474 ARM RISCix arm-*-* (as host)
3477 Configurations that have been declared obsolete will be commented out,
3478 but the code will be left in place. If there is no activity to revive
3479 these configurations before the next release of GDB, the sources will
3480 be permanently REMOVED.
3482 * Gould support removed
3484 Support for the Gould PowerNode and NP1 has been removed.
3486 * New features for SVR4
3488 On SVR4 native platforms (such as Solaris), if you attach to a process
3489 without first loading a symbol file, GDB will now attempt to locate and
3490 load symbols from the running process's executable file.
3492 * Many C++ enhancements
3494 C++ support has been greatly improved. Overload resolution now works properly
3495 in almost all cases. RTTI support is on the way.
3497 * Remote targets can connect to a sub-program
3499 A popen(3) style serial-device has been added. This device starts a
3500 sub-process (such as a stand-alone simulator) and then communicates
3501 with that. The sub-program to run is specified using the syntax
3502 ``|<program> <args>'' vis:
3504 (gdb) set remotedebug 1
3505 (gdb) target extended-remote |mn10300-elf-sim program-args
3507 * MIPS 64 remote protocol
3509 A long standing bug in the mips64 remote protocol where by GDB
3510 expected certain 32 bit registers (ex SR) to be transfered as 32
3511 instead of 64 bits has been fixed.
3513 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3514 added to provide backward compatibility with older versions of GDB.
3516 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3518 The command ``set remotebinarydownload'' command has been replaced by
3519 ``set remote X-packet''. Other commands in ``set remote'' family
3520 include ``set remote P-packet''.
3522 * Breakpoint commands accept ranges.
3524 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3525 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3526 ``tracepoint passcount'' also accepts a range of tracepoints.
3528 * ``apropos'' command added.
3530 The ``apropos'' command searches through command names and
3531 documentation strings, printing out matches, making it much easier to
3532 try to find a command that does what you are looking for.
3536 A new machine oriented interface (MI) has been added to GDB. This
3537 interface is designed for debug environments running GDB as a separate
3538 process. This is part of the long term libGDB project. See the
3539 "GDB/MI" chapter of the GDB manual for further information. It can be
3540 enabled by configuring with:
3542 .../configure --enable-gdbmi
3544 *** Changes in GDB-4.18:
3546 * New native configurations
3548 HP-UX 10.20 hppa*-*-hpux10.20
3549 HP-UX 11.x hppa*-*-hpux11.0*
3550 M68K GNU/Linux m68*-*-linux*
3554 Fujitsu FR30 fr30-*-elf*
3555 Intel StrongARM strongarm-*-*
3556 Mitsubishi D30V d30v-*-*
3558 * OBSOLETE configurations
3560 Gould PowerNode, NP1 np1-*-*, pn-*-*
3562 Configurations that have been declared obsolete will be commented out,
3563 but the code will be left in place. If there is no activity to revive
3564 these configurations before the next release of GDB, the sources will
3565 be permanently REMOVED.
3569 As a compatibility experiment, GDB's source files buildsym.h and
3570 buildsym.c have been converted to pure standard C, no longer
3571 containing any K&R compatibility code. We believe that all systems in
3572 use today either come with a standard C compiler, or have a GCC port
3573 available. If this is not true, please report the affected
3574 configuration to bug-gdb@gnu.org immediately. See the README file for
3575 information about getting a standard C compiler if you don't have one
3580 GDB now uses readline 2.2.
3582 * set extension-language
3584 You can now control the mapping between filename extensions and source
3585 languages by using the `set extension-language' command. For instance,
3586 you can ask GDB to treat .c files as C++ by saying
3587 set extension-language .c c++
3588 The command `info extensions' lists all of the recognized extensions
3589 and their associated languages.
3591 * Setting processor type for PowerPC and RS/6000
3593 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3594 you can use the `set processor' command to specify what variant of the
3595 PowerPC family you are debugging. The command
3599 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3600 following PowerPC and RS6000 variants:
3602 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3603 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3605 403GC IBM PowerPC 403GC
3606 505 Motorola PowerPC 505
3607 860 Motorola PowerPC 860 or 850
3608 601 Motorola PowerPC 601
3609 602 Motorola PowerPC 602
3610 603 Motorola/IBM PowerPC 603 or 603e
3611 604 Motorola PowerPC 604 or 604e
3612 750 Motorola/IBM PowerPC 750 or 750
3614 At the moment, this command just tells GDB what to name the
3615 special-purpose processor registers. Since almost all the affected
3616 registers are inaccessible to user-level programs, this command is
3617 only useful for remote debugging in its present form.
3621 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3622 more extensive support for HP-UX. Added features include shared
3623 library support, kernel threads and hardware watchpoints for 11.00,
3624 support for HP's ANSI C and C++ compilers, and a compatibility mode
3625 for xdb and dbx commands.
3629 HP's donation includes the new concept of catchpoints, which is a
3630 generalization of the old catch command. On HP-UX, it is now possible
3631 to catch exec, fork, and vfork, as well as library loading.
3633 This means that the existing catch command has changed; its first
3634 argument now specifies the type of catch to be set up. See the
3635 output of "help catch" for a list of catchpoint types.
3637 * Debugging across forks
3639 On HP-UX, you can choose which process to debug when a fork() happens
3644 HP has donated a curses-based terminal user interface (TUI). To get
3645 it, build with --enable-tui. Although this can be enabled for any
3646 configuration, at present it only works for native HP debugging.
3648 * GDB remote protocol additions
3650 A new protocol packet 'X' that writes binary data is now available.
3651 Default behavior is to try 'X', then drop back to 'M' if the stub
3652 fails to respond. The settable variable `remotebinarydownload'
3653 allows explicit control over the use of 'X'.
3655 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3656 full 64-bit address. The command
3658 set remoteaddresssize 32
3660 can be used to revert to the old behaviour. For existing remote stubs
3661 the change should not be noticed, as the additional address information
3664 In order to assist in debugging stubs, you may use the maintenance
3665 command `packet' to send any text string to the stub. For instance,
3667 maint packet heythere
3669 sends the packet "$heythere#<checksum>". Note that it is very easy to
3670 disrupt a debugging session by sending the wrong packet at the wrong
3673 The compare-sections command allows you to compare section data on the
3674 target to what is in the executable file without uploading or
3675 downloading, by comparing CRC checksums.
3677 * Tracing can collect general expressions
3679 You may now collect general expressions at tracepoints. This requires
3680 further additions to the target-side stub; see tracepoint.c and
3681 doc/agentexpr.texi for further details.
3683 * mask-address variable for Mips
3685 For Mips targets, you may control the zeroing of the upper 32 bits of
3686 a 64-bit address by entering `set mask-address on'. This is mainly
3687 of interest to users of embedded R4xxx and R5xxx processors.
3689 * Higher serial baud rates
3691 GDB's serial code now allows you to specify baud rates 57600, 115200,
3692 230400, and 460800 baud. (Note that your host system may not be able
3693 to achieve all of these rates.)
3697 The i960 configuration now includes an initial implementation of a
3698 builtin simulator, contributed by Jim Wilson.
3701 *** Changes in GDB-4.17:
3703 * New native configurations
3705 Alpha GNU/Linux alpha*-*-linux*
3706 Unixware 2.x i[3456]86-unixware2*
3707 Irix 6.x mips*-sgi-irix6*
3708 PowerPC GNU/Linux powerpc-*-linux*
3709 PowerPC Solaris powerpcle-*-solaris*
3710 Sparc GNU/Linux sparc-*-linux*
3711 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3715 Argonaut Risc Chip (ARC) arc-*-*
3716 Hitachi H8/300S h8300*-*-*
3717 Matsushita MN10200 w/simulator mn10200-*-*
3718 Matsushita MN10300 w/simulator mn10300-*-*
3719 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3720 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3721 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3722 Mitsubishi D10V w/simulator d10v-*-*
3723 Mitsubishi M32R/D w/simulator m32r-*-elf*
3724 Tsqware Sparclet sparclet-*-*
3725 NEC V850 w/simulator v850-*-*
3727 * New debugging protocols
3729 ARM with RDI protocol arm*-*-*
3730 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3731 DDB and LSI variants of PMON protocol mips*-*-*
3732 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3733 PowerPC with SDS protocol powerpc{,le}-*-eabi
3734 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3738 All configurations can now understand and use the DWARF 2 debugging
3739 format. The choice is automatic, if the symbol file contains DWARF 2
3744 GDB now includes basic Java language support. This support is
3745 only useful with Java compilers that produce native machine code.
3747 * solib-absolute-prefix and solib-search-path
3749 For SunOS and SVR4 shared libraries, you may now set the prefix for
3750 loading absolute shared library symbol files, and the search path for
3751 locating non-absolute shared library symbol files.
3753 * Live range splitting
3755 GDB can now effectively debug code for which GCC has performed live
3756 range splitting as part of its optimization. See gdb/doc/LRS for
3757 more details on the expected format of the stabs information.
3761 GDB's support for the GNU Hurd, including thread debugging, has been
3762 updated to work with current versions of the Hurd.
3766 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3767 instruction set. ARM GDB automatically detects when Thumb
3768 instructions are in use, and adjusts disassembly and backtracing
3773 GDB's MIPS target configurations now handle the MIP16 16-bit
3778 GDB now includes support for overlays; if an executable has been
3779 linked such that multiple sections are based at the same address, GDB
3780 will decide which section to use for symbolic info. You can choose to
3781 control the decision manually, using overlay commands, or implement
3782 additional target-side support and use "overlay load-target" to bring
3783 in the overlay mapping. Do "help overlay" for more detail.
3787 The command "info symbol <address>" displays information about
3788 the symbol at the specified address.
3792 The standard remote protocol now includes an extension that allows
3793 asynchronous collection and display of trace data. This requires
3794 extensive support in the target-side debugging stub. Tracing mode
3795 includes a new interaction mode in GDB and new commands: see the
3796 file tracepoint.c for more details.
3800 Configurations for embedded MIPS now include a simulator contributed
3801 by Cygnus Solutions. The simulator supports the instruction sets
3802 of most MIPS variants.
3806 Sparc configurations may now include the ERC32 simulator contributed
3807 by the European Space Agency. The simulator is not built into
3808 Sparc targets by default; configure with --enable-sim to include it.
3812 For target configurations that may include multiple variants of a
3813 basic architecture (such as MIPS and SH), you may now set the
3814 architecture explicitly. "set arch" sets, "info arch" lists
3815 the possible architectures.
3817 *** Changes in GDB-4.16:
3819 * New native configurations
3821 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3822 M68K NetBSD m68k-*-netbsd*
3823 PowerPC AIX 4.x powerpc-*-aix*
3824 PowerPC MacOS powerpc-*-macos*
3825 PowerPC Windows NT powerpcle-*-cygwin32
3826 RS/6000 AIX 4.x rs6000-*-aix4*
3830 ARM with RDP protocol arm-*-*
3831 I960 with MON960 i960-*-coff
3832 MIPS VxWorks mips*-*-vxworks*
3833 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3834 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3836 Matra Sparclet sparclet-*-*
3840 The powerpc-eabi configuration now includes the PSIM simulator,
3841 contributed by Andrew Cagney, with assistance from Mike Meissner.
3842 PSIM is a very elaborate model of the PowerPC, including not only
3843 basic instruction set execution, but also details of execution unit
3844 performance and I/O hardware. See sim/ppc/README for more details.
3848 GDB now works with Solaris 2.5.
3850 * Windows 95/NT native
3852 GDB will now work as a native debugger on Windows 95 and Windows NT.
3853 To build it from source, you must use the "gnu-win32" environment,
3854 which uses a DLL to emulate enough of Unix to run the GNU tools.
3855 Further information, binaries, and sources are available at
3856 ftp.cygnus.com, under pub/gnu-win32.
3858 * dont-repeat command
3860 If a user-defined command includes the command `dont-repeat', then the
3861 command will not be repeated if the user just types return. This is
3862 useful if the command is time-consuming to run, so that accidental
3863 extra keystrokes don't run the same command many times.
3865 * Send break instead of ^C
3867 The standard remote protocol now includes an option to send a break
3868 rather than a ^C to the target in order to interrupt it. By default,
3869 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3871 * Remote protocol timeout
3873 The standard remote protocol includes a new variable `remotetimeout'
3874 that allows you to set the number of seconds before GDB gives up trying
3875 to read from the target. The default value is 2.
3877 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3879 By default GDB will automatically keep track of objects as they are
3880 loaded and unloaded by the dynamic linker. By using the command `set
3881 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3882 when shared library events occur, thus allowing you to set breakpoints
3883 in shared libraries which are explicitly loaded by the inferior.
3885 Note this feature does not work on hpux8. On hpux9 you must link
3886 /usr/lib/end.o into your program. This feature should work
3887 automatically on hpux10.
3889 * Irix 5.x hardware watchpoint support
3891 Irix 5 configurations now support the use of hardware watchpoints.
3893 * Mips protocol "SYN garbage limit"
3895 When debugging a Mips target using the `target mips' protocol, you
3896 may set the number of characters that GDB will ignore by setting
3897 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3898 every character. The default value is 1050.
3900 * Recording and replaying remote debug sessions
3902 If you set `remotelogfile' to the name of a file, gdb will write to it
3903 a recording of a remote debug session. This recording may then be
3904 replayed back to gdb using "gdbreplay". See gdbserver/README for
3905 details. This is useful when you have a problem with GDB while doing
3906 remote debugging; you can make a recording of the session and send it
3907 to someone else, who can then recreate the problem.
3909 * Speedups for remote debugging
3911 GDB includes speedups for downloading and stepping MIPS systems using
3912 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3913 and more efficient S-record downloading.
3915 * Memory use reductions and statistics collection
3917 GDB now uses less memory and reports statistics about memory usage.
3918 Try the `maint print statistics' command, for example.
3920 *** Changes in GDB-4.15:
3922 * Psymtabs for XCOFF
3924 The symbol reader for AIX GDB now uses partial symbol tables. This
3925 can greatly improve startup time, especially for large executables.
3927 * Remote targets use caching
3929 Remote targets now use a data cache to speed up communication with the
3930 remote side. The data cache could lead to incorrect results because
3931 it doesn't know about volatile variables, thus making it impossible to
3932 debug targets which use memory mapped I/O devices. `set remotecache
3933 off' turns the the data cache off.
3935 * Remote targets may have threads
3937 The standard remote protocol now includes support for multiple threads
3938 in the target system, using new protocol commands 'H' and 'T'. See
3939 gdb/remote.c for details.
3943 If GDB is configured with `--enable-netrom', then it will include
3944 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3945 acts as though it is a bank of ROM on the target board, but you can
3946 write into it over the network. GDB's support consists only of
3947 support for fast loading into the emulated ROM; to debug, you must use
3948 another protocol, such as standard remote protocol. The usual
3949 sequence is something like
3951 target nrom <netrom-hostname>
3953 target remote <netrom-hostname>:1235
3957 GDB now includes support for the Apple Macintosh, as a host only. It
3958 may be run as either an MPW tool or as a standalone application, and
3959 it can debug through the serial port. All the usual GDB commands are
3960 available, but to the target command, you must supply "serial" as the
3961 device type instead of "/dev/ttyXX". See mpw-README in the main
3962 directory for more information on how to build. The MPW configuration
3963 scripts */mpw-config.in support only a few targets, and only the
3964 mips-idt-ecoff target has been tested.
3968 GDB configuration now uses autoconf. This is not user-visible,
3969 but does simplify configuration and building.
3973 GDB now supports hpux10.
3975 *** Changes in GDB-4.14:
3977 * New native configurations
3979 x86 FreeBSD i[345]86-*-freebsd
3980 x86 NetBSD i[345]86-*-netbsd
3981 NS32k NetBSD ns32k-*-netbsd
3982 Sparc NetBSD sparc-*-netbsd
3986 A29K VxWorks a29k-*-vxworks
3987 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3988 CPU32 EST-300 emulator m68*-*-est*
3989 PowerPC ELF powerpc-*-elf
3992 * Alpha OSF/1 support for procfs
3994 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3995 possible to attach to running processes. As the mounting of the /proc
3996 filesystem is optional on the Alpha, GDB automatically determines
3997 the availability of /proc during startup. This can lead to problems
3998 if /proc is unmounted after GDB has been started.
4000 * Arguments to user-defined commands
4002 User commands may accept up to 10 arguments separated by whitespace.
4003 Arguments are accessed within the user command via $arg0..$arg9. A
4006 print $arg0 + $arg1 + $arg2
4008 To execute the command use:
4011 Defines the command "adder" which prints the sum of its three arguments.
4012 Note the arguments are text substitutions, so they may reference variables,
4013 use complex expressions, or even perform inferior function calls.
4015 * New `if' and `while' commands
4017 This makes it possible to write more sophisticated user-defined
4018 commands. Both commands take a single argument, which is the
4019 expression to evaluate, and must be followed by the commands to
4020 execute, one per line, if the expression is nonzero, the list being
4021 terminated by the word `end'. The `if' command list may include an
4022 `else' word, which causes the following commands to be executed only
4023 if the expression is zero.
4025 * Fortran source language mode
4027 GDB now includes partial support for Fortran 77. It will recognize
4028 Fortran programs and can evaluate a subset of Fortran expressions, but
4029 variables and functions may not be handled correctly. GDB will work
4030 with G77, but does not yet know much about symbols emitted by other
4033 * Better HPUX support
4035 Most debugging facilities now work on dynamic executables for HPPAs
4036 running hpux9 or later. You can attach to running dynamically linked
4037 processes, but by default the dynamic libraries will be read-only, so
4038 for instance you won't be able to put breakpoints in them. To change
4039 that behavior do the following before running the program:
4045 This will cause the libraries to be mapped private and read-write.
4046 To revert to the normal behavior, do this:
4052 You cannot set breakpoints or examine data in the library until after
4053 the library is loaded if the function/data symbols do not have
4056 GDB can now also read debug symbols produced by the HP C compiler on
4057 HPPAs (sorry, no C++, Fortran or 68k support).
4059 * Target byte order now dynamically selectable
4061 You can choose which byte order to use with a target system, via the
4062 commands "set endian big" and "set endian little", and you can see the
4063 current setting by using "show endian". You can also give the command
4064 "set endian auto", in which case GDB will use the byte order
4065 associated with the executable. Currently, only embedded MIPS
4066 configurations support dynamic selection of target byte order.
4068 * New DOS host serial code
4070 This version uses DPMI interrupts to handle buffered I/O, so you
4071 no longer need to run asynctsr when debugging boards connected to
4074 *** Changes in GDB-4.13:
4076 * New "complete" command
4078 This lists all the possible completions for the rest of the line, if it
4079 were to be given as a command itself. This is intended for use by emacs.
4081 * Trailing space optional in prompt
4083 "set prompt" no longer adds a space for you after the prompt you set. This
4084 allows you to set a prompt which ends in a space or one that does not.
4086 * Breakpoint hit counts
4088 "info break" now displays a count of the number of times the breakpoint
4089 has been hit. This is especially useful in conjunction with "ignore"; you
4090 can ignore a large number of breakpoint hits, look at the breakpoint info
4091 to see how many times the breakpoint was hit, then run again, ignoring one
4092 less than that number, and this will get you quickly to the last hit of
4095 * Ability to stop printing at NULL character
4097 "set print null-stop" will cause GDB to stop printing the characters of
4098 an array when the first NULL is encountered. This is useful when large
4099 arrays actually contain only short strings.
4101 * Shared library breakpoints
4103 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4104 breakpoints in shared libraries before the executable is run.
4106 * Hardware watchpoints
4108 There is a new hardware breakpoint for the watch command for sparclite
4109 targets. See gdb/sparclite/hw_breakpoint.note.
4111 Hardware watchpoints are also now supported under GNU/Linux.
4115 Annotations have been added. These are for use with graphical interfaces,
4116 and are still experimental. Currently only gdba.el uses these.
4118 * Improved Irix 5 support
4120 GDB now works properly with Irix 5.2.
4122 * Improved HPPA support
4124 GDB now works properly with the latest GCC and GAS.
4126 * New native configurations
4128 Sequent PTX4 i[34]86-sequent-ptx4
4129 HPPA running OSF/1 hppa*-*-osf*
4130 Atari TT running SVR4 m68*-*-sysv4*
4131 RS/6000 LynxOS rs6000-*-lynxos*
4135 OS/9000 i[34]86-*-os9k
4136 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4139 * Hitachi SH7000 and E7000-PC ICE support
4141 There is now support for communicating with the Hitachi E7000-PC ICE.
4142 This is available automatically when GDB is configured for the SH.
4146 As usual, a variety of small fixes and improvements, both generic
4147 and configuration-specific. See the ChangeLog for more detail.
4149 *** Changes in GDB-4.12:
4151 * Irix 5 is now supported
4155 GDB-4.12 on the HPPA has a number of changes which make it unable
4156 to debug the output from the currently released versions of GCC and
4157 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4158 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4159 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4162 *** Changes in GDB-4.11:
4164 * User visible changes:
4168 The "set remotedebug" option is now consistent between the mips remote
4169 target, remote targets using the gdb-specific protocol, UDI (AMD's
4170 debug protocol for the 29k) and the 88k bug monitor. It is now an
4171 integer specifying a debug level (normally 0 or 1, but 2 means more
4172 debugging info for the mips target).
4174 * DEC Alpha native support
4176 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4177 debug info, but GDB works fairly well with the DEC compiler and should
4178 work with a future GCC release. See the README file for a few
4179 Alpha-specific notes.
4181 * Preliminary thread implementation
4183 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4185 * LynxOS native and target support for 386
4187 This release has been hosted on LynxOS 2.2, and also can be configured
4188 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4191 * Improvements in C++ mangling/demangling.
4193 This release has much better g++ debugging, specifically in name
4194 mangling/demangling, virtual function calls, print virtual table,
4195 call methods, ...etc.
4197 *** Changes in GDB-4.10:
4199 * User visible changes:
4201 Remote debugging using the GDB-specific (`target remote') protocol now
4202 supports the `load' command. This is only useful if you have some
4203 other way of getting the stub to the target system, and you can put it
4204 somewhere in memory where it won't get clobbered by the download.
4206 Filename completion now works.
4208 When run under emacs mode, the "info line" command now causes the
4209 arrow to point to the line specified. Also, "info line" prints
4210 addresses in symbolic form (as well as hex).
4212 All vxworks based targets now support a user settable option, called
4213 vxworks-timeout. This option represents the number of seconds gdb
4214 should wait for responses to rpc's. You might want to use this if
4215 your vxworks target is, perhaps, a slow software simulator or happens
4216 to be on the far side of a thin network line.
4220 This release contains support for using a DEC alpha as a GDB host for
4221 cross debugging. Native alpha debugging is not supported yet.
4224 *** Changes in GDB-4.9:
4228 This is the first GDB release which is accompanied by a matching testsuite.
4229 The testsuite requires installation of dejagnu, which should be available
4230 via ftp from most sites that carry GNU software.
4234 'Cfront' style demangling has had its name changed to 'ARM' style, to
4235 emphasize that it was written from the specifications in the C++ Annotated
4236 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4237 disclaimers, it still generated too much confusion with users attempting to
4238 use gdb with AT&T cfront.
4242 GDB now uses a standard remote interface to a simulator library.
4243 So far, the library contains simulators for the Zilog Z8001/2, the
4244 Hitachi H8/300, H8/500 and Super-H.
4246 * New targets supported
4248 H8/300 simulator h8300-hitachi-hms or h8300hms
4249 H8/500 simulator h8500-hitachi-hms or h8500hms
4250 SH simulator sh-hitachi-hms or sh
4251 Z8000 simulator z8k-zilog-none or z8ksim
4252 IDT MIPS board over serial line mips-idt-ecoff
4254 Cross-debugging to GO32 targets is supported. It requires a custom
4255 version of the i386-stub.c module which is integrated with the
4256 GO32 memory extender.
4258 * New remote protocols
4260 MIPS remote debugging protocol.
4262 * New source languages supported
4264 This version includes preliminary support for Chill, a Pascal like language
4265 used by telecommunications companies. Chill support is also being integrated
4266 into the GNU compiler, but we don't know when it will be publically available.
4269 *** Changes in GDB-4.8:
4271 * HP Precision Architecture supported
4273 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4274 version of this support was available as a set of patches from the
4275 University of Utah. GDB does not support debugging of programs
4276 compiled with the HP compiler, because HP will not document their file
4277 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4278 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4280 Many problems in the preliminary version have been fixed.
4282 * Faster and better demangling
4284 We have improved template demangling and fixed numerous bugs in the GNU style
4285 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4286 character types (wchar_t) are now supported. Demangling of each symbol is now
4287 only done once, and is cached when the symbol table for a file is read in.
4288 This results in a small increase in memory usage for C programs, a moderate
4289 increase in memory usage for C++ programs, and a fantastic speedup in
4292 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4293 from the specifications in the Annotated Reference Manual, which AT&T's
4294 compiler does not actually implement.
4296 * G++ multiple inheritance compiler problem
4298 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4299 inheritance lattices was reworked to properly discover ambiguities. We
4300 recently found an example which causes this new algorithm to fail in a
4301 very subtle way, producing bad debug information for those classes.
4302 The file 'gcc.patch' (in this directory) can be applied to gcc to
4303 circumvent the problem. A future GCC release will contain a complete
4306 The previous G++ debug info problem (mentioned below for the gdb-4.7
4307 release) is fixed in gcc version 2.3.2.
4309 * Improved configure script
4311 The `configure' script will now attempt to guess your system type if
4312 you don't supply a host system type. The old scheme of supplying a
4313 host system triplet is preferable over using this. All the magic is
4314 done in the new `config.guess' script. Examine it for details.
4316 We have also brought our configure script much more in line with the FSF's
4317 version. It now supports the --with-xxx options. In particular,
4318 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4319 The resulting GDB will not be able to read arbitrary object file formats --
4320 only the format ``expected'' to be used on the configured target system.
4321 We hope to make this the default in a future release.
4323 * Documentation improvements
4325 There's new internal documentation on how to modify GDB, and how to
4326 produce clean changes to the code. We implore people to read it
4327 before submitting changes.
4329 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4330 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4331 `info' files are also provided. To build `info' files from scratch,
4332 you will need the latest `makeinfo' release, which will be available in
4333 a future texinfo-X.Y release.
4335 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4336 We're not sure exactly which versions have this problem, but it has
4337 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4338 or better. If that isn't possible, there is a patch in
4339 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4340 around this problem.
4344 GDB now supports array constants that can be used in expressions typed in by
4345 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4346 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4349 The new directory `gdb/sparclite' contains a program that demonstrates
4350 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4352 * New native hosts supported
4354 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4355 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4357 * New targets supported
4359 AMD 29k family via UDI a29k-amd-udi or udi29k
4361 * New file formats supported
4363 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4364 HPUX core files, and SCO 3.2v2 core files.
4368 Attaching to processes now works again; thanks for the many bug reports.
4370 We have also stomped on a bunch of core dumps caused by
4371 printf_filtered("%s") problems.
4373 We eliminated a copyright problem on the rpc and ptrace header files
4374 for VxWorks, which was discovered at the last minute during the 4.7
4375 release. You should now be able to build a VxWorks GDB.
4377 You can now interrupt gdb while an attached process is running. This
4378 will cause the attached process to stop, and give control back to GDB.
4380 We fixed problems caused by using too many file descriptors
4381 for reading symbols from object files and libraries. This was
4382 especially a problem for programs that used many (~100) shared
4385 The `step' command now only enters a subroutine if there is line number
4386 information for the subroutine. Otherwise it acts like the `next'
4387 command. Previously, `step' would enter subroutines if there was
4388 any debugging information about the routine. This avoids problems
4389 when using `cc -g1' on MIPS machines.
4391 * Internal improvements
4393 GDB's internal interfaces have been improved to make it easier to support
4394 debugging of multiple languages in the future.
4396 GDB now uses a common structure for symbol information internally.
4397 Minimal symbols (derived from linkage symbols in object files), partial
4398 symbols (from a quick scan of debug information), and full symbols
4399 contain a common subset of information, making it easier to write
4400 shared code that handles any of them.
4402 * New command line options
4404 We now accept --silent as an alias for --quiet.
4408 The memory-mapped-malloc library is now licensed under the GNU Library
4409 General Public License.
4411 *** Changes in GDB-4.7:
4413 * Host/native/target split
4415 GDB has had some major internal surgery to untangle the support for
4416 hosts and remote targets. Now, when you configure GDB for a remote
4417 target, it will no longer load in all of the support for debugging
4418 local programs on the host. When fully completed and tested, this will
4419 ensure that arbitrary host/target combinations are possible.
4421 The primary conceptual shift is to separate the non-portable code in
4422 GDB into three categories. Host specific code is required any time GDB
4423 is compiled on that host, regardless of the target. Target specific
4424 code relates to the peculiarities of the target, but can be compiled on
4425 any host. Native specific code is everything else: it can only be
4426 built when the host and target are the same system. Child process
4427 handling and core file support are two common `native' examples.
4429 GDB's use of /proc for controlling Unix child processes is now cleaner.
4430 It has been split out into a single module under the `target_ops' vector,
4431 plus two native-dependent functions for each system that uses /proc.
4433 * New hosts supported
4435 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4436 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4437 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4439 * New targets supported
4441 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4442 68030 and CPU32 m68030-*-*, m68332-*-*
4444 * New native hosts supported
4446 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4447 (386bsd is not well tested yet)
4448 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4450 * New file formats supported
4452 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4453 supports reading of `a.out.adobe' object files, which are an a.out
4454 format extended with minimal information about multiple sections.
4458 `show copying' is the same as the old `info copying'.
4459 `show warranty' is the same as `info warrantee'.
4460 These were renamed for consistency. The old commands continue to work.
4462 `info handle' is a new alias for `info signals'.
4464 You can now define pre-command hooks, which attach arbitrary command
4465 scripts to any command. The commands in the hook will be executed
4466 prior to the user's command. You can also create a hook which will be
4467 executed whenever the program stops. See gdb.texinfo.
4471 We now deal with Cfront style name mangling, and can even extract type
4472 info from mangled symbols. GDB can automatically figure out which
4473 symbol mangling style your C++ compiler uses.
4475 Calling of methods and virtual functions has been improved as well.
4479 The crash that occured when debugging Sun Ansi-C compiled binaries is
4480 fixed. This was due to mishandling of the extra N_SO stabs output
4483 We also finally got Ultrix 4.2 running in house, and fixed core file
4484 support, with help from a dozen people on the net.
4486 John M. Farrell discovered that the reason that single-stepping was so
4487 slow on all of the Mips based platforms (primarily SGI and DEC) was
4488 that we were trying to demangle and lookup a symbol used for internal
4489 purposes on every instruction that was being stepped through. Changing
4490 the name of that symbol so that it couldn't be mistaken for a C++
4491 mangled symbol sped things up a great deal.
4493 Rich Pixley sped up symbol lookups in general by getting much smarter
4494 about when C++ symbol mangling is necessary. This should make symbol
4495 completion (TAB on the command line) much faster. It's not as fast as
4496 we'd like, but it's significantly faster than gdb-4.6.
4500 A new user controllable variable 'call_scratch_address' can
4501 specify the location of a scratch area to be used when GDB
4502 calls a function in the target. This is necessary because the
4503 usual method of putting the scratch area on the stack does not work
4504 in systems that have separate instruction and data spaces.
4506 We integrated changes to support the 29k UDI (Universal Debugger
4507 Interface), but discovered at the last minute that we didn't have all
4508 of the appropriate copyright paperwork. We are working with AMD to
4509 resolve this, and hope to have it available soon.
4513 We have sped up the remote serial line protocol, especially for targets
4514 with lots of registers. It now supports a new `expedited status' ('T')
4515 message which can be used in place of the existing 'S' status message.
4516 This allows the remote stub to send only the registers that GDB
4517 needs to make a quick decision about single-stepping or conditional
4518 breakpoints, eliminating the need to fetch the entire register set for
4519 each instruction being stepped through.
4521 The GDB remote serial protocol now implements a write-through cache for
4522 registers, only re-reading the registers if the target has run.
4524 There is also a new remote serial stub for SPARC processors. You can
4525 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4526 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4527 processor with a serial port.
4531 Configure.in files have become much easier to read and modify. A new
4532 `table driven' format makes it more obvious what configurations are
4533 supported, and what files each one uses.
4537 There is a new opcodes library which will eventually contain all of the
4538 disassembly routines and opcode tables. At present, it only contains
4539 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4540 disassembler (binutils/objdump) to share these routines.
4542 The libiberty library is now copylefted under the GNU Library General
4543 Public License. This allows more liberal use, and was done so libg++
4544 can use it. This makes no difference to GDB, since the Library License
4545 grants all the rights from the General Public License.
4549 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4550 reference to the stabs symbol info used by the debugger. It is (as far
4551 as we know) the only published document on this fascinating topic. We
4552 encourage you to read it, compare it to the stabs information on your
4553 system, and send improvements on the document in general (to
4554 bug-gdb@prep.ai.mit.edu).
4556 And, of course, many bugs have been fixed.
4559 *** Changes in GDB-4.6:
4561 * Better support for C++ function names
4563 GDB now accepts as input the "demangled form" of C++ overloaded function
4564 names and member function names, and can do command completion on such names
4565 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4566 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4567 Make use of command completion, it is your friend.
4569 GDB also now accepts a variety of C++ mangled symbol formats. They are
4570 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4571 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4572 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4573 for the list of formats.
4575 * G++ symbol mangling problem
4577 Recent versions of gcc have a bug in how they emit debugging information for
4578 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4579 directory) can be applied to gcc to fix the problem. Alternatively, if you
4580 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4581 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4582 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4585 * New 'maintenance' command
4587 All of the commands related to hacking GDB internals have been moved out of
4588 the main command set, and now live behind the 'maintenance' command. This
4589 can also be abbreviated as 'mt'. The following changes were made:
4591 dump-me -> maintenance dump-me
4592 info all-breakpoints -> maintenance info breakpoints
4593 printmsyms -> maintenance print msyms
4594 printobjfiles -> maintenance print objfiles
4595 printpsyms -> maintenance print psymbols
4596 printsyms -> maintenance print symbols
4598 The following commands are new:
4600 maintenance demangle Call internal GDB demangler routine to
4601 demangle a C++ link name and prints the result.
4602 maintenance print type Print a type chain for a given symbol
4604 * Change to .gdbinit file processing
4606 We now read the $HOME/.gdbinit file before processing the argv arguments
4607 (e.g. reading symbol files or core files). This allows global parameters to
4608 be set, which will apply during the symbol reading. The ./.gdbinit is still
4609 read after argv processing.
4611 * New hosts supported
4613 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4615 GNU/Linux support i386-unknown-linux or linux
4617 We are also including code to support the HP/PA running BSD and HPUX. This
4618 is almost guaranteed not to work, as we didn't have time to test or build it
4619 for this release. We are including it so that the more adventurous (or
4620 masochistic) of you can play with it. We also had major problems with the
4621 fact that the compiler that we got from HP doesn't support the -g option.
4624 * New targets supported
4626 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4628 * More smarts about finding #include files
4630 GDB now remembers the compilation directory for all include files, and for
4631 all files from which C is generated (like yacc and lex sources). This
4632 greatly improves GDB's ability to find yacc/lex sources, and include files,
4633 especially if you are debugging your program from a directory different from
4634 the one that contains your sources.
4636 We also fixed a bug which caused difficulty with listing and setting
4637 breakpoints in include files which contain C code. (In the past, you had to
4638 try twice in order to list an include file that you hadn't looked at before.)
4640 * Interesting infernals change
4642 GDB now deals with arbitrary numbers of sections, where the symbols for each
4643 section must be relocated relative to that section's landing place in the
4644 target's address space. This work was needed to support ELF with embedded
4645 stabs used by Solaris-2.0.
4647 * Bug fixes (of course!)
4649 There have been loads of fixes for the following things:
4650 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4651 i960, stabs, DOS(GO32), procfs, etc...
4653 See the ChangeLog for details.
4655 *** Changes in GDB-4.5:
4657 * New machines supported (host and target)
4659 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4661 SGI Irix-4.x mips-sgi-irix4 or iris4
4663 * New malloc package
4665 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4666 Mmalloc is capable of handling mutiple heaps of memory. It is also
4667 capable of saving a heap to a file, and then mapping it back in later.
4668 This can be used to greatly speedup the startup of GDB by using a
4669 pre-parsed symbol table which lives in a mmalloc managed heap. For
4670 more details, please read mmalloc/mmalloc.texi.
4674 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4675 'help info proc' for details.
4677 * MIPS ecoff symbol table format
4679 The code that reads MIPS symbol table format is now supported on all hosts.
4680 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4683 * File name changes for MS-DOS
4685 Many files in the config directories have been renamed to make it easier to
4686 support GDB on MS-DOSe systems (which have very restrictive file name
4687 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4688 environment) is close to working but has some remaining problems. Note
4689 that debugging of DOS programs is not supported, due to limitations
4690 in the ``operating system'', but it can be used to host cross-debugging.
4692 * Cross byte order fixes
4694 Many fixes have been made to support cross debugging of Sparc and MIPS
4695 targets from hosts whose byte order differs.
4697 * New -mapped and -readnow options
4699 If memory-mapped files are available on your system through the 'mmap'
4700 system call, you can use the -mapped option on the `file' or
4701 `symbol-file' commands to cause GDB to write the symbols from your
4702 program into a reusable file. If the program you are debugging is
4703 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4704 Future GDB debugging sessions will notice the presence of this file,
4705 and will quickly map in symbol information from it, rather than reading
4706 the symbol table from the executable program. Using the '-mapped'
4707 option in a GDB `file' or `symbol-file' command has the same effect as
4708 starting GDB with the '-mapped' command-line option.
4710 You can cause GDB to read the entire symbol table immediately by using
4711 the '-readnow' option with any of the commands that load symbol table
4712 information (or on the GDB command line). This makes the command
4713 slower, but makes future operations faster.
4715 The -mapped and -readnow options are typically combined in order to
4716 build a `fred.syms' file that contains complete symbol information.
4717 A simple GDB invocation to do nothing but build a `.syms' file for future
4720 gdb -batch -nx -mapped -readnow programname
4722 The `.syms' file is specific to the host machine on which GDB is run.
4723 It holds an exact image of GDB's internal symbol table. It cannot be
4724 shared across multiple host platforms.
4726 * longjmp() handling
4728 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4729 siglongjmp() without losing control. This feature has not yet been ported to
4730 all systems. It currently works on many 386 platforms, all MIPS-based
4731 platforms (SGI, DECstation, etc), and Sun3/4.
4735 Preliminary work has been put in to support the new Solaris OS from Sun. At
4736 this time, it can control and debug processes, but it is not capable of
4741 As always, many many bug fixes. The major areas were with g++, and mipsread.
4742 People using the MIPS-based platforms should experience fewer mysterious
4743 crashes and trashed symbol tables.
4745 *** Changes in GDB-4.4:
4747 * New machines supported (host and target)
4749 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4751 BSD Reno on Vax vax-dec-bsd
4752 Ultrix on Vax vax-dec-ultrix
4754 * New machines supported (target)
4756 AMD 29000 embedded, using EBMON a29k-none-none
4760 GDB continues to improve its handling of C++. `References' work better.
4761 The demangler has also been improved, and now deals with symbols mangled as
4762 per the Annotated C++ Reference Guide.
4764 GDB also now handles `stabs' symbol information embedded in MIPS
4765 `ecoff' symbol tables. Since the ecoff format was not easily
4766 extensible to handle new languages such as C++, this appeared to be a
4767 good way to put C++ debugging info into MIPS binaries. This option
4768 will be supported in the GNU C compiler, version 2, when it is
4771 * New features for SVR4
4773 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4774 shared libraries. Debugging dynamically linked programs should present
4775 only minor differences from debugging statically linked programs.
4777 The `info proc' command will print out information about any process
4778 on an SVR4 system (including the one you are debugging). At the moment,
4779 it prints the address mappings of the process.
4781 If you bring up GDB on another SVR4 system, please send mail to
4782 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4784 * Better dynamic linking support in SunOS
4786 Reading symbols from shared libraries which contain debugging symbols
4787 now works properly. However, there remain issues such as automatic
4788 skipping of `transfer vector' code during function calls, which
4789 make it harder to debug code in a shared library, than to debug the
4790 same code linked statically.
4794 GDB is now using the latest `getopt' routines from the FSF. This
4795 version accepts the -- prefix for options with long names. GDB will
4796 continue to accept the old forms (-option and +option) as well.
4797 Various single letter abbreviations for options have been explicity
4798 added to the option table so that they won't get overshadowed in the
4799 future by other options that begin with the same letter.
4803 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4804 Many assorted bugs have been handled. Many more remain to be handled.
4805 See the various ChangeLog files (primarily in gdb and bfd) for details.
4808 *** Changes in GDB-4.3:
4810 * New machines supported (host and target)
4812 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4813 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4814 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4816 * Almost SCO Unix support
4818 We had hoped to support:
4819 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4820 (except for core file support), but we discovered very late in the release
4821 that it has problems with process groups that render gdb unusable. Sorry
4822 about that. I encourage people to fix it and post the fixes.
4824 * Preliminary ELF and DWARF support
4826 GDB can read ELF object files on System V Release 4, and can handle
4827 debugging records for C, in DWARF format, in ELF files. This support
4828 is preliminary. If you bring up GDB on another SVR4 system, please
4829 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4834 GDB now uses the latest `readline' library. One user-visible change
4835 is that two tabs will list possible command completions, which previously
4836 required typing M-? (meta-question mark, or ESC ?).
4840 The `stepi' bug that many of you noticed has been squashed.
4841 Many bugs in C++ have been handled. Many more remain to be handled.
4842 See the various ChangeLog files (primarily in gdb and bfd) for details.
4844 * State of the MIPS world (in case you wondered):
4846 GDB can understand the symbol tables emitted by the compilers
4847 supplied by most vendors of MIPS-based machines, including DEC. These
4848 symbol tables are in a format that essentially nobody else uses.
4850 Some versions of gcc come with an assembler post-processor called
4851 mips-tfile. This program is required if you want to do source-level
4852 debugging of gcc-compiled programs. I believe FSF does not ship
4853 mips-tfile with gcc version 1, but it will eventually come with gcc
4856 Debugging of g++ output remains a problem. g++ version 1.xx does not
4857 really support it at all. (If you're lucky, you should be able to get
4858 line numbers and stack traces to work, but no parameters or local
4859 variables.) With some work it should be possible to improve the
4862 When gcc version 2 is released, you will have somewhat better luck.
4863 However, even then you will get confusing results for inheritance and
4866 We will eventually provide full debugging of g++ output on
4867 DECstations. This will probably involve some kind of stabs-in-ecoff
4868 encapulation, but the details have not been worked out yet.
4871 *** Changes in GDB-4.2:
4873 * Improved configuration
4875 Only one copy of `configure' exists now, and it is not self-modifying.
4876 Porting BFD is simpler.
4880 The `step' and `next' commands now only stop at the first instruction
4881 of a source line. This prevents the multiple stops that used to occur
4882 in switch statements, for-loops, etc. `Step' continues to stop if a
4883 function that has debugging information is called within the line.
4887 Lots of small bugs fixed. More remain.
4889 * New host supported (not target)
4891 Intel 386 PC clone running Mach i386-none-mach
4894 *** Changes in GDB-4.1:
4896 * Multiple source language support
4898 GDB now has internal scaffolding to handle several source languages.
4899 It determines the type of each source file from its filename extension,
4900 and will switch expression parsing and number formatting to match the
4901 language of the function in the currently selected stack frame.
4902 You can also specifically set the language to be used, with
4903 `set language c' or `set language modula-2'.
4907 GDB now has preliminary support for the GNU Modula-2 compiler,
4908 currently under development at the State University of New York at
4909 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4910 continue through the fall of 1991 and into 1992.
4912 Other Modula-2 compilers are currently not supported, and attempting to
4913 debug programs compiled with them will likely result in an error as the
4914 symbol table is read. Feel free to work on it, though!
4916 There are hooks in GDB for strict type checking and range checking,
4917 in the `Modula-2 philosophy', but they do not currently work.
4921 GDB can now write to executable and core files (e.g. patch
4922 a variable's value). You must turn this switch on, specify
4923 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4924 by assigning a new value to a variable. Modifications take
4927 * Automatic SunOS shared library reading
4929 When you run your program, GDB automatically determines where its
4930 shared libraries (if any) have been loaded, and reads their symbols.
4931 The `share' command is no longer needed. This also works when
4932 examining core files.
4936 You can specify the number of lines that the `list' command shows.
4939 * New machines supported (host and target)
4941 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4942 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4943 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4945 * New hosts supported (not targets)
4947 IBM RT/PC: romp-ibm-aix or rtpc
4949 * New targets supported (not hosts)
4951 AMD 29000 embedded with COFF a29k-none-coff
4952 AMD 29000 embedded with a.out a29k-none-aout
4953 Ultracomputer remote kernel debug a29k-nyu-kern
4955 * New remote interfaces
4961 *** Changes in GDB-4.0:
4965 Wide output is wrapped at good places to make the output more readable.
4967 Gdb now supports cross-debugging from a host machine of one type to a
4968 target machine of another type. Communication with the target system
4969 is over serial lines. The ``target'' command handles connecting to the
4970 remote system; the ``load'' command will download a program into the
4971 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4972 also supports debugging of realtime processes running under VxWorks,
4973 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4974 stub on the target system.
4976 New CPUs supported include the AMD 29000 and Intel 960.
4978 GDB now reads object files and symbol tables via a ``binary file''
4979 library, which allows a single copy of GDB to debug programs of multiple
4980 object file types such as a.out and coff.
4982 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4983 refcard.dvi and refcard.ps are available to format it).
4986 * Control-Variable user interface simplified
4988 All variables that control the operation of the debugger can be set
4989 by the ``set'' command, and displayed by the ``show'' command.
4991 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4992 ``Show prompt'' produces the response:
4993 Gdb's prompt is new-gdb=>.
4995 What follows are the NEW set commands. The command ``help set'' will
4996 print a complete list of old and new set commands. ``help set FOO''
4997 will give a longer description of the variable FOO. ``show'' will show
4998 all of the variable descriptions and their current settings.
5000 confirm on/off: Enables warning questions for operations that are
5001 hard to recover from, e.g. rerunning the program while
5002 it is already running. Default is ON.
5004 editing on/off: Enables EMACS style command line editing
5005 of input. Previous lines can be recalled with
5006 control-P, the current line can be edited with control-B,
5007 you can search for commands with control-R, etc.
5010 history filename NAME: NAME is where the gdb command history
5011 will be stored. The default is .gdb_history,
5012 or the value of the environment variable
5015 history size N: The size, in commands, of the command history. The
5016 default is 256, or the value of the environment variable
5019 history save on/off: If this value is set to ON, the history file will
5020 be saved after exiting gdb. If set to OFF, the
5021 file will not be saved. The default is OFF.
5023 history expansion on/off: If this value is set to ON, then csh-like
5024 history expansion will be performed on
5025 command line input. The default is OFF.
5027 radix N: Sets the default radix for input and output. It can be set
5028 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5029 in the current radix, so "set radix 10" is always a no-op.
5031 height N: This integer value is the number of lines on a page. Default
5032 is 24, the current `stty rows'' setting, or the ``li#''
5033 setting from the termcap entry matching the environment
5036 width N: This integer value is the number of characters on a line.
5037 Default is 80, the current `stty cols'' setting, or the ``co#''
5038 setting from the termcap entry matching the environment
5041 Note: ``set screensize'' is obsolete. Use ``set height'' and
5042 ``set width'' instead.
5044 print address on/off: Print memory addresses in various command displays,
5045 such as stack traces and structure values. Gdb looks
5046 more ``symbolic'' if you turn this off; it looks more
5047 ``machine level'' with it on. Default is ON.
5049 print array on/off: Prettyprint arrays. New convenient format! Default
5052 print demangle on/off: Print C++ symbols in "source" form if on,
5055 print asm-demangle on/off: Same, for assembler level printouts
5058 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5061 * Support for Epoch Environment.
5063 The epoch environment is a version of Emacs v18 with windowing. One
5064 new command, ``inspect'', is identical to ``print'', except that if you
5065 are running in the epoch environment, the value is printed in its own
5069 * Support for Shared Libraries
5071 GDB can now debug programs and core files that use SunOS shared libraries.
5072 Symbols from a shared library cannot be referenced
5073 before the shared library has been linked with the program (this
5074 happens after you type ``run'' and before the function main() is entered).
5075 At any time after this linking (including when examining core files
5076 from dynamically linked programs), gdb reads the symbols from each
5077 shared library when you type the ``sharedlibrary'' command.
5078 It can be abbreviated ``share''.
5080 sharedlibrary REGEXP: Load shared object library symbols for files
5081 matching a unix regular expression. No argument
5082 indicates to load symbols for all shared libraries.
5084 info sharedlibrary: Status of loaded shared libraries.
5089 A watchpoint stops execution of a program whenever the value of an
5090 expression changes. Checking for this slows down execution
5091 tremendously whenever you are in the scope of the expression, but is
5092 quite useful for catching tough ``bit-spreader'' or pointer misuse
5093 problems. Some machines such as the 386 have hardware for doing this
5094 more quickly, and future versions of gdb will use this hardware.
5096 watch EXP: Set a watchpoint (breakpoint) for an expression.
5098 info watchpoints: Information about your watchpoints.
5100 delete N: Deletes watchpoint number N (same as breakpoints).
5101 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5102 enable N: Re-enables watchpoint number N (same as breakpoints).
5105 * C++ multiple inheritance
5107 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5110 * C++ exception handling
5112 Gdb now supports limited C++ exception handling. Besides the existing
5113 ability to breakpoint on an exception handler, gdb can breakpoint on
5114 the raising of an exception (before the stack is peeled back to the
5117 catch FOO: If there is a FOO exception handler in the dynamic scope,
5118 set a breakpoint to catch exceptions which may be raised there.
5119 Multiple exceptions (``catch foo bar baz'') may be caught.
5121 info catch: Lists all exceptions which may be caught in the
5122 current stack frame.
5125 * Minor command changes
5127 The command ``call func (arg, arg, ...)'' now acts like the print
5128 command, except it does not print or save a value if the function's result
5129 is void. This is similar to dbx usage.
5131 The ``up'' and ``down'' commands now always print the frame they end up
5132 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5133 frames without printing.
5135 * New directory command
5137 'dir' now adds directories to the FRONT of the source search path.
5138 The path starts off empty. Source files that contain debug information
5139 about the directory in which they were compiled can be found even
5140 with an empty path; Sun CC and GCC include this information. If GDB can't
5141 find your source file in the current directory, type "dir .".
5143 * Configuring GDB for compilation
5145 For normal use, type ``./configure host''. See README or gdb.texinfo
5148 GDB now handles cross debugging. If you are remotely debugging between
5149 two different machines, type ``./configure host -target=targ''.
5150 Host is the machine where GDB will run; targ is the machine
5151 where the program that you are debugging will run.