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 * The command 'forward-search' can now be abbreviated as 'fo'.
29 * New configure options
31 --enable-libmcheck/--disable-libmcheck
32 By default, development versions are built with -lmcheck on hosts
33 that support it, in order to help track memory corruption issues.
34 Release versions, on the other hand, are built without -lmcheck
35 by default. The --enable-libmcheck/--disable-libmcheck configure
36 options allow the user to override that default.
38 * New commands (for set/show, see "New options" below)
41 List the BFDs known to GDB.
43 python-interactive [command]
45 Start a Python interactive prompt, or evaluate the optional command
46 and print the result of expressions.
49 "py" is a new alias for "python".
53 ** For the Renesas Super-H architecture, the "regs" command has been removed
54 (has been deprecated in GDB 7.5), and "info all-registers" should be used
59 ** Command parameter changes are now notified using new async record
61 ** Trace frame changes caused by command "tfind" are now notified using
62 new async record "=traceframe-changed".
63 ** The creation and deletion of trace state variables are now notified
64 using new async records "=tsv-created" and "=tsv-deleted".
65 ** The start and stop of process record are now notified using new
66 async record "=record-started" and "=record-stopped".
67 ** Memory changes are now notified using new async record
69 ** The data-disassemble command response will include a "fullname" field
70 containing the absolute file name when GDB can determine it and source
73 *** Changes in GDB 7.5
75 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
76 for more x32 ABI info.
78 * GDB now supports access to MIPS DSP registers on Linux targets.
80 * GDB now supports debugging microMIPS binaries.
82 * The "info os" command on GNU/Linux can now display information on
83 several new classes of objects managed by the operating system:
84 "info os procgroups" lists process groups
85 "info os files" lists file descriptors
86 "info os sockets" lists internet-domain sockets
87 "info os shm" lists shared-memory regions
88 "info os semaphores" lists semaphores
89 "info os msg" lists message queues
90 "info os modules" lists loaded kernel modules
92 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
93 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
94 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
95 options and inspect the probe arguments using the new $_probe_arg family
96 of convenience variables. You can obtain more information about SystemTap
97 in <http://sourceware.org/systemtap/>.
99 * GDB now supports reversible debugging on ARM, it allows you to
100 debug basic ARM and THUMB instructions, and provides
101 record/replay support.
103 * The option "symbol-reloading" has been deleted as it is no longer used.
107 ** GDB commands implemented in Python can now be put in command class
110 ** The "maint set python print-stack on|off" is now deleted.
112 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
113 apply "flag enum"-style pretty-printing to any enum.
115 ** gdb.lookup_symbol can now work when there is no current frame.
117 ** gdb.Symbol now has a 'line' attribute, holding the line number in
118 the source at which the symbol was defined.
120 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
121 method 'value'. The former indicates whether the symbol needs a
122 frame in order to compute its value, and the latter computes the
125 ** A new method 'referenced_value' on gdb.Value objects which can
126 dereference pointer as well as C++ reference values.
128 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
129 which return the global and static blocks (as gdb.Block objects),
130 of the underlying symbol table, respectively.
132 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
133 object associated with a PC value.
135 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
136 of the address range occupied by code for the current source line.
138 * Go language support.
139 GDB now supports debugging programs written in the Go programming
142 * GDBserver now supports stdio connections.
143 E.g. (gdb) target remote | ssh myhost gdbserver - hello
145 * The binary "gdbtui" can no longer be built or installed.
146 Use "gdb -tui" instead.
148 * GDB will now print "flag" enums specially. A flag enum is one where
149 all the enumerator values have no bits in common when pairwise
150 "and"ed. When printing a value whose type is a flag enum, GDB will
151 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
152 (gdb) print (enum E) 3
155 * The filename part of a linespec will now match trailing components
156 of a source file name. For example, "break gcc/expr.c:1000" will
157 now set a breakpoint in build/gcc/expr.c, but not
160 * The "info proc" and "generate-core-file" commands will now also
161 work on remote targets connected to GDBserver on Linux.
163 * The command "info catch" has been removed. It has been disabled
166 * The "catch exception" and "catch assert" commands now accept
167 a condition at the end of the command, much like the "break"
168 command does. For instance:
170 (gdb) catch exception Constraint_Error if Barrier = True
172 Previously, it was possible to add a condition to such catchpoints,
173 but it had to be done as a second step, after the catchpoint had been
174 created, using the "condition" command.
176 * The "info static-tracepoint-marker" command will now also work on
177 native Linux targets with in-process agent.
179 * GDB can now set breakpoints on inlined functions.
181 * The .gdb_index section has been updated to include symbols for
182 inlined functions. GDB will ignore older .gdb_index sections by
183 default, which could cause symbol files to be loaded more slowly
184 until their .gdb_index sections can be recreated. The new command
185 "set use-deprecated-index-sections on" will cause GDB to use any older
186 .gdb_index sections it finds. This will restore performance, but the
187 ability to set breakpoints on inlined functions will be lost in symbol
188 files with older .gdb_index sections.
190 The .gdb_index section has also been updated to record more information
191 about each symbol. This speeds up the "info variables", "info functions"
192 and "info types" commands when used with programs having the .gdb_index
193 section, as well as speeding up debugging with shared libraries using
194 the .gdb_index section.
196 * Ada support for GDB/MI Variable Objects has been added.
198 * GDB can now support 'breakpoint always-inserted mode' in 'record'
203 ** New command -info-os is the MI equivalent of "info os".
205 ** Output logs ("set logging" and related) now include MI output.
209 ** "set use-deprecated-index-sections on|off"
210 "show use-deprecated-index-sections on|off"
211 Controls the use of deprecated .gdb_index sections.
213 ** "catch load" and "catch unload" can be used to stop when a shared
214 library is loaded or unloaded, respectively.
216 ** "enable count" can be used to auto-disable a breakpoint after
219 ** "info vtbl" can be used to show the virtual method tables for
220 C++ and Java objects.
222 ** "explore" and its sub commands "explore value" and "explore type"
223 can be used to reccursively explore values and types of
224 expressions. These commands are available only if GDB is
225 configured with '--with-python'.
227 ** "info auto-load" shows status of all kinds of auto-loaded files,
228 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
229 sequences of commands files, "info auto-load python-scripts"
230 shows status of auto-loading Python script files,
231 "info auto-load local-gdbinit" shows status of loading init file
232 (.gdbinit) from current directory and "info auto-load libthread-db" shows
233 status of inferior specific thread debugging shared library loading.
235 ** "info auto-load-scripts", "set auto-load-scripts on|off"
236 and "show auto-load-scripts" commands have been deprecated, use their
237 "info auto-load python-scripts", "set auto-load python-scripts on|off"
238 and "show auto-load python-scripts" counterparts instead.
240 ** "dprintf location,format,args..." creates a dynamic printf, which
241 is basically a breakpoint that does a printf and immediately
242 resumes your program's execution, so it is like a printf that you
243 can insert dynamically at runtime instead of at compiletime.
245 ** "set print symbol"
247 Controls whether GDB attempts to display the symbol, if any,
248 corresponding to addresses it prints. This defaults to "on", but
249 you can set it to "off" to restore GDB's previous behavior.
251 * Deprecated commands
253 ** For the Renesas Super-H architecture, the "regs" command has been
254 deprecated, and "info all-registers" should be used instead.
258 Renesas RL78 rl78-*-elf
259 HP OpenVMS ia64 ia64-hp-openvms*
261 * GDBserver supports evaluation of breakpoint conditions. When
262 support is advertised by GDBserver, GDB may be told to send the
263 breakpoint conditions in bytecode form to GDBserver. GDBserver
264 will only report the breakpoint trigger to GDB when its condition
270 show mips compression
271 Select the compressed ISA encoding used in functions that have no symbol
272 information available. The encoding can be set to either of:
275 and is updated automatically from ELF file flags if available.
277 set breakpoint condition-evaluation
278 show breakpoint condition-evaluation
279 Control whether breakpoint conditions are evaluated by GDB ("host") or by
280 GDBserver ("target"). Default option "auto" chooses the most efficient
282 This option can improve debugger efficiency depending on the speed of the
286 Disable auto-loading globally.
289 Show auto-loading setting of all kinds of auto-loaded files.
291 set auto-load gdb-scripts on|off
292 show auto-load gdb-scripts
293 Control auto-loading of GDB canned sequences of commands files.
295 set auto-load python-scripts on|off
296 show auto-load python-scripts
297 Control auto-loading of Python script files.
299 set auto-load local-gdbinit on|off
300 show auto-load local-gdbinit
301 Control loading of init file (.gdbinit) from current directory.
303 set auto-load libthread-db on|off
304 show auto-load libthread-db
305 Control auto-loading of inferior specific thread debugging shared library.
307 set auto-load scripts-directory <dir1>[:<dir2>...]
308 show auto-load scripts-directory
309 Set a list of directories from which to load auto-loaded scripts.
310 Automatically loaded Python scripts and GDB scripts are located in one
311 of the directories listed by this option.
312 The delimiter (':' above) may differ according to the host platform.
314 set auto-load safe-path <dir1>[:<dir2>...]
315 show auto-load safe-path
316 Set a list of directories from which it is safe to auto-load files.
317 The delimiter (':' above) may differ according to the host platform.
319 set debug auto-load on|off
321 Control display of debugging info for auto-loading the files above.
323 set dprintf-style gdb|call|agent
325 Control the way in which a dynamic printf is performed; "gdb"
326 requests a GDB printf command, while "call" causes dprintf to call a
327 function in the inferior. "agent" requests that the target agent
328 (such as GDBserver) do the printing.
330 set dprintf-function <expr>
331 show dprintf-function
332 set dprintf-channel <expr>
334 Set the function and optional first argument to the call when using
335 the "call" style of dynamic printf.
337 set disconnected-dprintf on|off
338 show disconnected-dprintf
339 Control whether agent-style dynamic printfs continue to be in effect
340 after GDB disconnects.
342 * New configure options
345 Configure default value for the 'set auto-load scripts-directory'
346 setting above. It defaults to '$debugdir:$datadir/auto-load',
347 $debugdir representing global debugging info directories (available
348 via 'show debug-file-directory') and $datadir representing GDB's data
349 directory (available via 'show data-directory').
351 --with-auto-load-safe-path
352 Configure default value for the 'set auto-load safe-path' setting
353 above. It defaults to the --with-auto-load-dir setting.
355 --without-auto-load-safe-path
356 Set 'set auto-load safe-path' to '/', effectively disabling this
361 z0/z1 conditional breakpoints extension
363 The z0/z1 breakpoint insertion packets have been extended to carry
364 a list of conditional expressions over to the remote stub depending on the
365 condition evaluation mode. The use of this extension can be controlled
366 via the "set remote conditional-breakpoints-packet" command.
370 Specify the signals which the remote stub may pass to the debugged
371 program without GDB involvement.
373 * New command line options
375 --init-command=FILE, -ix Like --command, -x but execute it
376 before loading inferior.
377 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
378 execute it before loading inferior.
380 *** Changes in GDB 7.4
382 * GDB now handles ambiguous linespecs more consistently; the existing
383 FILE:LINE support has been expanded to other types of linespecs. A
384 breakpoint will now be set on all matching locations in all
385 inferiors, and locations will be added or removed according to
388 * GDB now allows you to skip uninteresting functions and files when
389 stepping with the "skip function" and "skip file" commands.
391 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
392 and "show remote hardware-watchpoint-length-limit". These allows to
393 set or show the maximum length limit (in bytes) of a remote
394 target hardware watchpoint.
396 This allows e.g. to use "unlimited" hardware watchpoints with the
397 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
398 watchpoints are slower than real hardware watchpoints but are
399 significantly faster than gdb software watchpoints.
403 ** The register_pretty_printer function in module gdb.printing now takes
404 an optional `replace' argument. If True, the new printer replaces any
407 ** The "maint set python print-stack on|off" command has been
408 deprecated and will be deleted in GDB 7.5.
409 A new command: "set python print-stack none|full|message" has
410 replaced it. Additionally, the default for "print-stack" is
411 now "message", which just prints the error message without
414 ** A prompt substitution hook (prompt_hook) is now available to the
417 ** A new Python module, gdb.prompt has been added to the GDB Python
418 modules library. This module provides functionality for
419 escape sequences in prompts (used by set/show
420 extended-prompt). These escape sequences are replaced by their
423 ** Python commands and convenience-functions located in
424 'data-directory'/python/gdb/command and
425 'data-directory'/python/gdb/function are now automatically loaded
428 ** Blocks now provide four new attributes. global_block and
429 static_block will return the global and static blocks
430 respectively. is_static and is_global are boolean attributes
431 that indicate if the block is one of those two types.
433 ** Symbols now provide the "type" attribute, the type of the symbol.
435 ** The "gdb.breakpoint" function has been deprecated in favor of
438 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
439 of a function. This class is based on the "finish" command
440 available in the CLI.
442 ** Type objects for struct and union types now allow access to
443 the fields using standard Python dictionary (mapping) methods.
444 For example, "some_type['myfield']" now works, as does
447 ** A new event "gdb.new_objfile" has been added, triggered by loading a
450 ** A new function, "deep_items" has been added to the gdb.types
451 module in the GDB Python modules library. This function returns
452 an iterator over the fields of a struct or union type. Unlike
453 the standard Python "iteritems" method, it will recursively traverse
454 any anonymous fields.
458 ** "*stopped" events can report several new "reason"s, such as
461 ** Breakpoint changes are now notified using new async records, like
462 "=breakpoint-modified".
464 ** New command -ada-task-info.
466 * libthread-db-search-path now supports two special values: $sdir and $pdir.
467 $sdir specifies the default system locations of shared libraries.
468 $pdir specifies the directory where the libpthread used by the application
471 GDB no longer looks in $sdir and $pdir after it has searched the directories
472 mentioned in libthread-db-search-path. If you want to search those
473 directories, they must be specified in libthread-db-search-path.
474 The default value of libthread-db-search-path on GNU/Linux and Solaris
475 systems is now "$sdir:$pdir".
477 $pdir is not supported by gdbserver, it is currently ignored.
478 $sdir is supported by gdbserver.
480 * New configure option --with-iconv-bin.
481 When using the internationalization support like the one in the GNU C
482 library, GDB will invoke the "iconv" program to get a list of supported
483 character sets. If this program lives in a non-standard location, one can
484 use this option to specify where to find it.
486 * When natively debugging programs on PowerPC BookE processors running
487 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
488 watchpoints, which specify a mask in addition to an address to watch.
489 The mask specifies that some bits of an address (the bits which are
490 reset in the mask) should be ignored when matching the address accessed
491 by the inferior against the watchpoint address. See the "PowerPC Embedded"
492 section in the user manual for more details.
494 * The new option --once causes GDBserver to stop listening for connections once
495 the first connection is made. The listening port used by GDBserver will
496 become available after that.
498 * New commands "info macros" and "alias" have been added.
500 * New function parameters suffix @entry specifies value of function parameter
501 at the time the function got called. Entry values are available only since
507 "!" is now an alias of the "shell" command.
508 Note that no space is needed between "!" and SHELL COMMAND.
512 watch EXPRESSION mask MASK_VALUE
513 The watch command now supports the mask argument which allows creation
514 of masked watchpoints, if the current architecture supports this feature.
516 info auto-load-scripts [REGEXP]
517 This command was formerly named "maintenance print section-scripts".
518 It is now generally useful and is no longer a maintenance-only command.
520 info macro [-all] [--] MACRO
521 The info macro command has new options `-all' and `--'. The first for
522 printing all definitions of a macro. The second for explicitly specifying
523 the end of arguments and the beginning of the macro name in case the macro
524 name starts with a hyphen.
526 collect[/s] EXPRESSIONS
527 The tracepoint collect command now takes an optional modifier "/s"
528 that directs it to dereference pointer-to-character types and
529 collect the bytes of memory up to a zero byte. The behavior is
530 similar to what you see when you use the regular print command on a
531 string. An optional integer following the "/s" sets a bound on the
532 number of bytes that will be collected.
535 The trace start command now interprets any supplied arguments as a
536 note to be recorded with the trace run, with an effect similar to
537 setting the variable trace-notes.
540 The trace stop command now interprets any arguments as a note to be
541 mentioned along with the tstatus report that the trace was stopped
542 with a command. The effect is similar to setting the variable
545 * Tracepoints can now be enabled and disabled at any time after a trace
546 experiment has been started using the standard "enable" and "disable"
547 commands. It is now possible to start a trace experiment with no enabled
548 tracepoints; GDB will display a warning, but will allow the experiment to
549 begin, assuming that tracepoints will be enabled as needed while the trace
552 * Fast tracepoints on 32-bit x86-architectures can now be placed at
553 locations with 4-byte instructions, when they were previously
554 limited to locations with instructions of 5 bytes or longer.
558 set debug dwarf2-read
559 show debug dwarf2-read
560 Turns on or off display of debugging messages related to reading
561 DWARF debug info. The default is off.
563 set debug symtab-create
564 show debug symtab-create
565 Turns on or off display of debugging messages related to symbol table
566 creation. The default is off.
570 Set the GDB prompt, and allow escape sequences to be inserted to
571 display miscellaneous information (see 'help set extended-prompt'
572 for the list of sequences). This prompt (and any information
573 accessed through the escape sequences) is updated every time the
576 set print entry-values (both|compact|default|if-needed|no|only|preferred)
577 show print entry-values
578 Set printing of frame argument values at function entry. In some cases
579 GDB can determine the value of function argument which was passed by the
580 function caller, even if the value was modified inside the called function.
582 set debug entry-values
583 show debug entry-values
584 Control display of debugging info for determining frame argument values at
585 function entry and virtual tail call frames.
587 set basenames-may-differ
588 show basenames-may-differ
589 Set whether a source file may have multiple base names.
590 (A "base name" is the name of a file with the directory part removed.
591 Example: The base name of "/home/user/hello.c" is "hello.c".)
592 If set, GDB will canonicalize file names (e.g., expand symlinks)
593 before comparing them. Canonicalization is an expensive operation,
594 but it allows the same file be known by more than one base name.
595 If not set (the default), all source files are assumed to have just
596 one base name, and gdb will do file name comparisons more efficiently.
602 Set a user name and notes for the current and any future trace runs.
603 This is useful for long-running and/or disconnected traces, to
604 inform others (or yourself) as to who is running the trace, supply
605 contact information, or otherwise explain what is going on.
608 show trace-stop-notes
609 Set a note attached to the trace run, that is displayed when the
610 trace has been stopped by a tstop command. This is useful for
611 instance as an explanation, if you are stopping a trace run that was
612 started by someone else.
618 Dynamically enable a tracepoint in a started trace experiment.
622 Dynamically disable a tracepoint in a started trace experiment.
626 Set the user and notes of the trace run.
630 Query the current status of a tracepoint.
634 Query the minimum length of instruction at which a fast tracepoint may
637 * Dcache size (number of lines) and line-size are now runtime-configurable
638 via "set dcache line" and "set dcache line-size" commands.
642 Texas Instruments TMS320C6x tic6x-*-*
646 Renesas RL78 rl78-*-elf
648 *** Changes in GDB 7.3.1
650 * The build failure for NetBSD and OpenBSD targets have now been fixed.
652 *** Changes in GDB 7.3
654 * GDB has a new command: "thread find [REGEXP]".
655 It finds the thread id whose name, target id, or thread extra info
656 matches the given regular expression.
658 * The "catch syscall" command now works on mips*-linux* targets.
660 * The -data-disassemble MI command now supports modes 2 and 3 for
661 dumping the instruction opcodes.
663 * New command line options
665 -data-directory DIR Specify DIR as the "data-directory".
666 This is mostly for testing purposes.
668 * The "maint set python auto-load on|off" command has been renamed to
669 "set auto-load-scripts on|off".
671 * GDB has a new command: "set directories".
672 It is like the "dir" command except that it replaces the
673 source path list instead of augmenting it.
675 * GDB now understands thread names.
677 On GNU/Linux, "info threads" will display the thread name as set by
678 prctl or pthread_setname_np.
680 There is also a new command, "thread name", which can be used to
681 assign a name internally for GDB to display.
684 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
685 has been integrated into GDB.
689 ** The function gdb.Write now accepts an optional keyword 'stream'.
690 This keyword, when provided, will direct the output to either
691 stdout, stderr, or GDB's logging output.
693 ** Parameters can now be be sub-classed in Python, and in particular
694 you may implement the get_set_doc and get_show_doc functions.
695 This improves how Parameter set/show documentation is processed
696 and allows for more dynamic content.
698 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
699 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
700 have an is_valid method.
702 ** Breakpoints can now be sub-classed in Python, and in particular
703 you may implement a 'stop' function that is executed each time
704 the inferior reaches that breakpoint.
706 ** New function gdb.lookup_global_symbol looks up a global symbol.
708 ** GDB values in Python are now callable if the value represents a
709 function. For example, if 'some_value' represents a function that
710 takes two integer parameters and returns a value, you can call
711 that function like so:
713 result = some_value (10,20)
715 ** Module gdb.types has been added.
716 It contains a collection of utilities for working with gdb.Types objects:
717 get_basic_type, has_field, make_enum_dict.
719 ** Module gdb.printing has been added.
720 It contains utilities for writing and registering pretty-printers.
721 New classes: PrettyPrinter, SubPrettyPrinter,
722 RegexpCollectionPrettyPrinter.
723 New function: register_pretty_printer.
725 ** New commands "info pretty-printers", "enable pretty-printer" and
726 "disable pretty-printer" have been added.
728 ** gdb.parameter("directories") is now available.
730 ** New function gdb.newest_frame returns the newest frame in the
733 ** The gdb.InferiorThread class has a new "name" attribute. This
734 holds the thread's name.
736 ** Python Support for Inferior events.
737 Python scripts can add observers to be notified of events
738 occurring in the process being debugged.
739 The following events are currently supported:
740 - gdb.events.cont Continue event.
741 - gdb.events.exited Inferior exited event.
742 - gdb.events.stop Signal received, and Breakpoint hit events.
746 ** GDB now puts template parameters in scope when debugging in an
747 instantiation. For example, if you have:
749 template<int X> int func (void) { return X; }
751 then if you step into func<5>, "print X" will show "5". This
752 feature requires proper debuginfo support from the compiler; it
753 was added to GCC 4.5.
755 ** The motion commands "next", "finish", "until", and "advance" now
756 work better when exceptions are thrown. In particular, GDB will
757 no longer lose control of the inferior; instead, the GDB will
758 stop the inferior at the point at which the exception is caught.
759 This functionality requires a change in the exception handling
760 code that was introduced in GCC 4.5.
762 * GDB now follows GCC's rules on accessing volatile objects when
763 reading or writing target state during expression evaluation.
764 One notable difference to prior behavior is that "print x = 0"
765 no longer generates a read of x; the value of the assignment is
766 now always taken directly from the value being assigned.
768 * GDB now has some support for using labels in the program's source in
769 linespecs. For instance, you can use "advance label" to continue
770 execution to a label.
772 * GDB now has support for reading and writing a new .gdb_index
773 section. This section holds a fast index of DWARF debugging
774 information and can be used to greatly speed up GDB startup and
775 operation. See the documentation for `save gdb-index' for details.
777 * The "watch" command now accepts an optional "-location" argument.
778 When used, this causes GDB to watch the memory referred to by the
779 expression. Such a watchpoint is never deleted due to it going out
782 * GDB now supports thread debugging of core dumps on GNU/Linux.
784 GDB now activates thread debugging using the libthread_db library
785 when debugging GNU/Linux core dumps, similarly to when debugging
786 live processes. As a result, when debugging a core dump file, GDB
787 is now able to display pthread_t ids of threads. For example, "info
788 threads" shows the same output as when debugging the process when it
789 was live. In earlier releases, you'd see something like this:
792 * 1 LWP 6780 main () at main.c:10
794 While now you see this:
797 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
799 It is also now possible to inspect TLS variables when debugging core
802 When debugging a core dump generated on a machine other than the one
803 used to run GDB, you may need to point GDB at the correct
804 libthread_db library with the "set libthread-db-search-path"
805 command. See the user manual for more details on this command.
807 * When natively debugging programs on PowerPC BookE processors running
808 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
809 which stop execution of the inferior whenever it executes an instruction
810 at any address within the specified range. See the "PowerPC Embedded"
811 section in the user manual for more details.
813 * New features in the GDB remote stub, GDBserver
815 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
816 and i686 LynxOS (version 5.x).
818 ** GDBserver is now supported on Blackfin Linux.
820 * New native configurations
822 ia64 HP-UX ia64-*-hpux*
826 Analog Devices, Inc. Blackfin Processor bfin-*
828 * Ada task switching is now supported on sparc-elf targets when
829 debugging a program using the Ravenscar Profile. For more information,
830 see the "Tasking Support when using the Ravenscar Profile" section
831 in the GDB user manual.
833 * Guile support was removed.
835 * New features in the GNU simulator
837 ** The --map-info flag lists all known core mappings.
839 ** CFI flashes may be simulated via the "cfi" device.
841 *** Changes in GDB 7.2
843 * Shared library support for remote targets by default
845 When GDB is configured for a generic, non-OS specific target, like
846 for example, --target=arm-eabi or one of the many *-*-elf targets,
847 GDB now queries remote stubs for loaded shared libraries using the
848 `qXfer:libraries:read' packet. Previously, shared library support
849 was always disabled for such configurations.
853 ** Argument Dependent Lookup (ADL)
855 In C++ ADL lookup directs function search to the namespaces of its
856 arguments even if the namespace has not been imported.
866 Here the compiler will search for `foo' in the namespace of 'b'
867 and find A::foo. GDB now supports this. This construct is commonly
868 used in the Standard Template Library for operators.
870 ** Improved User Defined Operator Support
872 In addition to member operators, GDB now supports lookup of operators
873 defined in a namespace and imported with a `using' directive, operators
874 defined in the global scope, operators imported implicitly from an
875 anonymous namespace, and the ADL operators mentioned in the previous
877 GDB now also supports proper overload resolution for all the previously
878 mentioned flavors of operators.
880 ** static const class members
882 Printing of static const class members that are initialized in the
883 class definition has been fixed.
885 * Windows Thread Information Block access.
887 On Windows targets, GDB now supports displaying the Windows Thread
888 Information Block (TIB) structure. This structure is visible either
889 by using the new command `info w32 thread-information-block' or, by
890 dereferencing the new convenience variable named `$_tlb', a
891 thread-specific pointer to the TIB. This feature is also supported
892 when remote debugging using GDBserver.
896 Static tracepoints are calls in the user program into a tracing
897 library. One such library is a port of the LTTng kernel tracer to
898 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
899 When debugging with GDBserver, GDB now supports combining the GDB
900 tracepoint machinery with such libraries. For example: the user can
901 use GDB to probe a static tracepoint marker (a call from the user
902 program into the tracing library) with the new "strace" command (see
903 "New commands" below). This creates a "static tracepoint" in the
904 breakpoint list, that can be manipulated with the same feature set
905 as fast and regular tracepoints. E.g., collect registers, local and
906 global variables, collect trace state variables, and define
907 tracepoint conditions. In addition, the user can collect extra
908 static tracepoint marker specific data, by collecting the new
909 $_sdata internal variable. When analyzing the trace buffer, you can
910 inspect $_sdata like any other variable available to GDB. For more
911 information, see the "Tracepoints" chapter in GDB user manual. New
912 remote packets have been defined to support static tracepoints, see
913 the "New remote packets" section below.
915 * Better reconstruction of tracepoints after disconnected tracing
917 GDB will attempt to download the original source form of tracepoint
918 definitions when starting a trace run, and then will upload these
919 upon reconnection to the target, resulting in a more accurate
920 reconstruction of the tracepoints that are in use on the target.
924 You can now exercise direct control over the ways that GDB can
925 affect your program. For instance, you can disallow the setting of
926 breakpoints, so that the program can run continuously (assuming
927 non-stop mode). In addition, the "observer" variable is available
928 to switch all of the different controls; in observer mode, GDB
929 cannot affect the target's behavior at all, which is useful for
930 tasks like diagnosing live systems in the field.
932 * The new convenience variable $_thread holds the number of the
939 Return the address of the Windows Thread Information Block of a given thread.
943 In response to several of the tracepoint packets, the target may now
944 also respond with a number of intermediate `qRelocInsn' request
945 packets before the final result packet, to have GDB handle
946 relocating an instruction to execute at a different address. This
947 is particularly useful for stubs that support fast tracepoints. GDB
948 reports support for this feature in the qSupported packet.
952 List static tracepoint markers in the target program.
956 List static tracepoint markers at a given address in the target
959 qXfer:statictrace:read
961 Read the static trace data collected (by a `collect $_sdata'
962 tracepoint action). The remote stub reports support for this packet
963 to gdb's qSupported query.
967 Send the current settings of GDB's permission flags.
971 Send part of the source (textual) form of a tracepoint definition,
972 which includes location, conditional, and action list.
974 * The source command now accepts a -s option to force searching for the
975 script in the source search path even if the script name specifies
978 * New features in the GDB remote stub, GDBserver
980 - GDBserver now support tracepoints (including fast tracepoints, and
981 static tracepoints). The feature is currently supported by the
982 i386-linux and amd64-linux builds. See the "Tracepoints support
983 in gdbserver" section in the manual for more information.
985 GDBserver JIT compiles the tracepoint's conditional agent
986 expression bytecode into native code whenever possible for low
987 overhead dynamic tracepoints conditionals. For such tracepoints,
988 an expression that examines program state is evaluated when the
989 tracepoint is reached, in order to determine whether to capture
990 trace data. If the condition is simple and false, processing the
991 tracepoint finishes very quickly and no data is gathered.
993 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
994 for static tracepoints support.
996 - GDBserver now supports x86_64 Windows 64-bit debugging.
998 * GDB now sends xmlRegisters= in qSupported packet to indicate that
999 it understands register description.
1001 * The --batch flag now disables pagination and queries.
1003 * X86 general purpose registers
1005 GDB now supports reading/writing byte, word and double-word x86
1006 general purpose registers directly. This means you can use, say,
1007 $ah or $ax to refer, respectively, to the byte register AH and
1008 16-bit word register AX that are actually portions of the 32-bit
1009 register EAX or 64-bit register RAX.
1011 * The `commands' command now accepts a range of breakpoints to modify.
1012 A plain `commands' following a command that creates multiple
1013 breakpoints affects all the breakpoints set by that command. This
1014 applies to breakpoints set by `rbreak', and also applies when a
1015 single `break' command creates multiple breakpoints (e.g.,
1016 breakpoints on overloaded c++ functions).
1018 * The `rbreak' command now accepts a filename specification as part of
1019 its argument, limiting the functions selected by the regex to those
1020 in the specified file.
1022 * Support for remote debugging Windows and SymbianOS shared libraries
1023 from Unix hosts has been improved. Non Windows GDB builds now can
1024 understand target reported file names that follow MS-DOS based file
1025 system semantics, such as file names that include drive letters and
1026 use the backslash character as directory separator. This makes it
1027 possible to transparently use the "set sysroot" and "set
1028 solib-search-path" on Unix hosts to point as host copies of the
1029 target's shared libraries. See the new command "set
1030 target-file-system-kind" described below, and the "Commands to
1031 specify files" section in the user manual for more information.
1035 eval template, expressions...
1036 Convert the values of one or more expressions under the control
1037 of the string template to a command line, and call it.
1039 set target-file-system-kind unix|dos-based|auto
1040 show target-file-system-kind
1041 Set or show the assumed file system kind for target reported file
1044 save breakpoints <filename>
1045 Save all current breakpoint definitions to a file suitable for use
1046 in a later debugging session. To read the saved breakpoint
1047 definitions, use the `source' command.
1049 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1052 info static-tracepoint-markers
1053 Display information about static tracepoint markers in the target.
1055 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1056 Define a static tracepoint by probing a marker at the given
1057 function, line, address, or marker ID.
1061 Enable and disable observer mode.
1063 set may-write-registers on|off
1064 set may-write-memory on|off
1065 set may-insert-breakpoints on|off
1066 set may-insert-tracepoints on|off
1067 set may-insert-fast-tracepoints on|off
1068 set may-interrupt on|off
1069 Set individual permissions for GDB effects on the target. Note that
1070 some of these settings can have undesirable or surprising
1071 consequences, particularly when changed in the middle of a session.
1072 For instance, disabling the writing of memory can prevent
1073 breakpoints from being inserted, cause single-stepping to fail, or
1074 even crash your program, if you disable after breakpoints have been
1075 inserted. However, GDB should not crash.
1077 set record memory-query on|off
1078 show record memory-query
1079 Control whether to stop the inferior if memory changes caused
1080 by an instruction cannot be recorded.
1085 The disassemble command now supports "start,+length" form of two arguments.
1089 ** GDB now provides a new directory location, called the python directory,
1090 where Python scripts written for GDB can be installed. The location
1091 of that directory is <data-directory>/python, where <data-directory>
1092 is the GDB data directory. For more details, see section `Scripting
1093 GDB using Python' in the manual.
1095 ** The GDB Python API now has access to breakpoints, symbols, symbol
1096 tables, program spaces, inferiors, threads and frame's code blocks.
1097 Additionally, GDB Parameters can now be created from the API, and
1098 manipulated via set/show in the CLI.
1100 ** New functions gdb.target_charset, gdb.target_wide_charset,
1101 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1103 ** New exception gdb.GdbError.
1105 ** Pretty-printers are now also looked up in the current program space.
1107 ** Pretty-printers can now be individually enabled and disabled.
1109 ** GDB now looks for names of Python scripts to auto-load in a
1110 special section named `.debug_gdb_scripts', in addition to looking
1111 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1113 * Tracepoint actions were unified with breakpoint commands. In particular,
1114 there are no longer differences in "info break" output for breakpoints and
1115 tracepoints and the "commands" command can be used for both tracepoints and
1116 regular breakpoints.
1120 ARM Symbian arm*-*-symbianelf*
1122 * D language support.
1123 GDB now supports debugging programs written in the D programming
1126 * GDB now supports the extended ptrace interface for PowerPC which is
1127 available since Linux kernel version 2.6.34. This automatically enables
1128 any hardware breakpoints and additional hardware watchpoints available in
1129 the processor. The old ptrace interface exposes just one hardware
1130 watchpoint and no hardware breakpoints.
1132 * GDB is now able to use the Data Value Compare (DVC) register available on
1133 embedded PowerPC processors to implement in hardware simple watchpoint
1134 conditions of the form:
1136 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1138 This works in native GDB running on Linux kernels with the extended ptrace
1139 interface mentioned above.
1141 *** Changes in GDB 7.1
1145 ** Namespace Support
1147 GDB now supports importing of namespaces in C++. This enables the
1148 user to inspect variables from imported namespaces. Support for
1149 namepace aliasing has also been added. So, if a namespace is
1150 aliased in the current scope (e.g. namepace C=A; ) the user can
1151 print variables using the alias (e.g. (gdb) print C::x).
1155 All known bugs relating to the printing of virtual base class were
1156 fixed. It is now possible to call overloaded static methods using a
1161 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1162 and reinterpret_cast<> are now handled by the C++ expression parser.
1166 Xilinx MicroBlaze microblaze-*-*
1171 Xilinx MicroBlaze microblaze
1174 * Multi-program debugging.
1176 GDB now has support for multi-program (a.k.a. multi-executable or
1177 multi-exec) debugging. This allows for debugging multiple inferiors
1178 simultaneously each running a different program under the same GDB
1179 session. See "Debugging Multiple Inferiors and Programs" in the
1180 manual for more information. This implied some user visible changes
1181 in the multi-inferior support. For example, "info inferiors" now
1182 lists inferiors that are not running yet or that have exited
1183 already. See also "New commands" and "New options" below.
1185 * New tracing features
1187 GDB's tracepoint facility now includes several new features:
1189 ** Trace state variables
1191 GDB tracepoints now include support for trace state variables, which
1192 are variables managed by the target agent during a tracing
1193 experiment. They are useful for tracepoints that trigger each
1194 other, so for instance one tracepoint can count hits in a variable,
1195 and then a second tracepoint has a condition that is true when the
1196 count reaches a particular value. Trace state variables share the
1197 $-syntax of GDB convenience variables, and can appear in both
1198 tracepoint actions and condition expressions. Use the "tvariable"
1199 command to create, and "info tvariables" to view; see "Trace State
1200 Variables" in the manual for more detail.
1204 GDB now includes an option for defining fast tracepoints, which
1205 targets may implement more efficiently, such as by installing a jump
1206 into the target agent rather than a trap instruction. The resulting
1207 speedup can be by two orders of magnitude or more, although the
1208 tradeoff is that some program locations on some target architectures
1209 might not allow fast tracepoint installation, for instance if the
1210 instruction to be replaced is shorter than the jump. To request a
1211 fast tracepoint, use the "ftrace" command, with syntax identical to
1212 the regular trace command.
1214 ** Disconnected tracing
1216 It is now possible to detach GDB from the target while it is running
1217 a trace experiment, then reconnect later to see how the experiment
1218 is going. In addition, a new variable disconnected-tracing lets you
1219 tell the target agent whether to continue running a trace if the
1220 connection is lost unexpectedly.
1224 GDB now has the ability to save the trace buffer into a file, and
1225 then use that file as a target, similarly to you can do with
1226 corefiles. You can select trace frames, print data that was
1227 collected in them, and use tstatus to display the state of the
1228 tracing run at the moment that it was saved. To create a trace
1229 file, use "tsave <filename>", and to use it, do "target tfile
1232 ** Circular trace buffer
1234 You can ask the target agent to handle the trace buffer as a
1235 circular buffer, discarding the oldest trace frames to make room for
1236 newer ones, by setting circular-trace-buffer to on. This feature may
1237 not be available for all target agents.
1242 The disassemble command, when invoked with two arguments, now requires
1243 the arguments to be comma-separated.
1246 The info variables command now displays variable definitions. Files
1247 which only declare a variable are not shown.
1250 The source command is now capable of sourcing Python scripts.
1251 This feature is dependent on the debugger being build with Python
1254 Related to this enhancement is also the introduction of a new command
1255 "set script-extension" (see below).
1257 * New commands (for set/show, see "New options" below)
1259 record save [<FILENAME>]
1260 Save a file (in core file format) containing the process record
1261 execution log for replay debugging at a later time.
1263 record restore <FILENAME>
1264 Restore the process record execution log that was saved at an
1265 earlier time, for replay debugging.
1267 add-inferior [-copies <N>] [-exec <FILENAME>]
1270 clone-inferior [-copies <N>] [ID]
1271 Make a new inferior ready to execute the same program another
1272 inferior has loaded.
1277 maint info program-spaces
1278 List the program spaces loaded into GDB.
1280 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1281 show remote interrupt-sequence
1282 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1283 as the sequence to the remote target in order to interrupt the execution.
1284 Ctrl-C is a default. Some system prefers BREAK which is high level of
1285 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1286 Magic SysRq g. It is BREAK signal and character 'g'.
1288 set remote interrupt-on-connect [on | off]
1289 show remote interrupt-on-connect
1290 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1291 remote target when gdb connects to it. This is needed when you debug
1294 set remotebreak [on | off]
1296 Deprecated. Use "set/show remote interrupt-sequence" instead.
1298 tvariable $NAME [ = EXP ]
1299 Create or modify a trace state variable.
1302 List trace state variables and their values.
1304 delete tvariable $NAME ...
1305 Delete one or more trace state variables.
1308 Evaluate the given expressions without collecting anything into the
1309 trace buffer. (Valid in tracepoint actions only.)
1311 ftrace FN / FILE:LINE / *ADDR
1312 Define a fast tracepoint at the given function, line, or address.
1314 * New expression syntax
1316 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1317 GDB now parses 0b101010 identically with 42.
1321 set follow-exec-mode new|same
1322 show follow-exec-mode
1323 Control whether GDB reuses the same inferior across an exec call or
1324 creates a new one. This is useful to be able to restart the old
1325 executable after the inferior having done an exec call.
1327 set default-collect EXPR, ...
1328 show default-collect
1329 Define a list of expressions to be collected at each tracepoint.
1330 This is a useful way to ensure essential items are not overlooked,
1331 such as registers or a critical global variable.
1333 set disconnected-tracing
1334 show disconnected-tracing
1335 If set to 1, the target is instructed to continue tracing if it
1336 loses its connection to GDB. If 0, the target is to stop tracing
1339 set circular-trace-buffer
1340 show circular-trace-buffer
1341 If set to on, the target is instructed to use a circular trace buffer
1342 and discard the oldest trace frames instead of stopping the trace due
1343 to a full trace buffer. If set to off, the trace stops when the buffer
1344 fills up. Some targets may not support this.
1346 set script-extension off|soft|strict
1347 show script-extension
1348 If set to "off", the debugger does not perform any script language
1349 recognition, and all sourced files are assumed to be GDB scripts.
1350 If set to "soft" (the default), files are sourced according to
1351 filename extension, falling back to GDB scripts if the first
1353 If set to "strict", files are sourced according to filename extension.
1355 set ada trust-PAD-over-XVS on|off
1356 show ada trust-PAD-over-XVS
1357 If off, activate a workaround against a bug in the debugging information
1358 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1359 the GCC sources for more information about the GNAT encoding and
1360 PAD types in particular). It is always safe to set this option to
1361 off, but this introduces a slight performance penalty. The default
1364 * Python API Improvements
1366 ** GDB provides the new class gdb.LazyString. This is useful in
1367 some pretty-printing cases. The new method gdb.Value.lazy_string
1368 provides a simple way to create objects of this type.
1370 ** The fields returned by gdb.Type.fields now have an
1371 `is_base_class' attribute.
1373 ** The new method gdb.Type.range returns the range of an array type.
1375 ** The new method gdb.parse_and_eval can be used to parse and
1376 evaluate an expression.
1378 * New remote packets
1381 Define a trace state variable.
1384 Get the current value of a trace state variable.
1387 Set desired tracing behavior upon disconnection.
1390 Set the trace buffer to be linear or circular.
1393 Get data about the tracepoints currently in use.
1397 Process record now works correctly with hardware watchpoints.
1399 Multiple bug fixes have been made to the mips-irix port, making it
1400 much more reliable. In particular:
1401 - Debugging threaded applications is now possible again. Previously,
1402 GDB would hang while starting the program, or while waiting for
1403 the program to stop at a breakpoint.
1404 - Attaching to a running process no longer hangs.
1405 - An error occurring while loading a core file has been fixed.
1406 - Changing the value of the PC register now works again. This fixes
1407 problems observed when using the "jump" command, or when calling
1408 a function from GDB, or even when assigning a new value to $pc.
1409 - With the "finish" and "return" commands, the return value for functions
1410 returning a small array is now correctly printed.
1411 - It is now possible to break on shared library code which gets executed
1412 during a shared library init phase (code executed while executing
1413 their .init section). Previously, the breakpoint would have no effect.
1414 - GDB is now able to backtrace through the signal handler for
1415 non-threaded programs.
1417 PIE (Position Independent Executable) programs debugging is now supported.
1418 This includes debugging execution of PIC (Position Independent Code) shared
1419 libraries although for that, it should be possible to run such libraries as an
1422 *** Changes in GDB 7.0
1424 * GDB now has an interface for JIT compilation. Applications that
1425 dynamically generate code can create symbol files in memory and register
1426 them with GDB. For users, the feature should work transparently, and
1427 for JIT developers, the interface is documented in the GDB manual in the
1428 "JIT Compilation Interface" chapter.
1430 * Tracepoints may now be conditional. The syntax is as for
1431 breakpoints; either an "if" clause appended to the "trace" command,
1432 or the "condition" command is available. GDB sends the condition to
1433 the target for evaluation using the same bytecode format as is used
1434 for tracepoint actions.
1436 * The disassemble command now supports: an optional /r modifier, print the
1437 raw instructions in hex as well as in symbolic form, and an optional /m
1438 modifier to print mixed source+assembly.
1440 * Process record and replay
1442 In a architecture environment that supports ``process record and
1443 replay'', ``process record and replay'' target can record a log of
1444 the process execution, and replay it with both forward and reverse
1447 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1448 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1449 set execution-direction {forward|reverse}, for targets that support
1452 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1453 feature is available with a native GDB running on kernel version
1456 * GDB now has support for multi-byte and wide character sets on the
1457 target. Strings whose character type is wchar_t, char16_t, or
1458 char32_t are now correctly printed. GDB supports wide- and unicode-
1459 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1460 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1461 `printf'. This feature requires iconv to work properly; if your
1462 system does not have a working iconv, GDB can use GNU libiconv. See
1463 the installation instructions for more information.
1465 * GDB now supports automatic retrieval of shared library files from
1466 remote targets. To use this feature, specify a system root that begins
1467 with the `remote:' prefix, either via the `set sysroot' command or via
1468 the `--with-sysroot' configure-time option.
1470 * "info sharedlibrary" now takes an optional regex of libraries to show,
1471 and it now reports if a shared library has no debugging information.
1473 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1474 now complete on file names.
1476 * When completing in expressions, gdb will attempt to limit
1477 completions to allowable structure or union fields, where appropriate.
1478 For instance, consider:
1480 # struct example { int f1; double f2; };
1481 # struct example variable;
1484 If the user types TAB at the end of this command line, the available
1485 completions will be "f1" and "f2".
1487 * Inlined functions are now supported. They show up in backtraces, and
1488 the "step", "next", and "finish" commands handle them automatically.
1490 * GDB now supports the token-splicing (##) and stringification (#)
1491 operators when expanding macros. It also supports variable-arity
1494 * GDB now supports inspecting extra signal information, exported by
1495 the new $_siginfo convenience variable. The feature is currently
1496 implemented on linux ARM, i386 and amd64.
1498 * GDB can now display the VFP floating point registers and NEON vector
1499 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1500 can provide these registers (requires Linux 2.6.30 or later). Remote
1501 and simulator targets may also provide them.
1503 * New remote packets
1506 Search memory for a sequence of bytes.
1509 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1510 operation over reliable transport links. Use of this packet is
1511 controlled by the `set remote noack-packet' command.
1514 Kill the process with the specified process ID. Use this in preference
1515 to `k' when multiprocess protocol extensions are supported.
1518 Obtains additional operating system information
1522 Read or write additional signal information.
1524 * Removed remote protocol undocumented extension
1526 An undocumented extension to the remote protocol's `S' stop reply
1527 packet that permited the stub to pass a process id was removed.
1528 Remote servers should use the `T' stop reply packet instead.
1530 * GDB now supports multiple function calling conventions according to the
1531 DWARF-2 DW_AT_calling_convention function attribute.
1533 * The SH target utilizes the aforementioned change to distinguish between gcc
1534 and Renesas calling convention. It also adds the new CLI commands
1535 `set/show sh calling-convention'.
1537 * GDB can now read compressed debug sections, as produced by GNU gold
1538 with the --compress-debug-sections=zlib flag.
1540 * 64-bit core files are now supported on AIX.
1542 * Thread switching is now supported on Tru64.
1544 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1545 which will be allocated using malloc later in program execution.
1547 * The qXfer:libraries:read remote procotol packet now allows passing a
1548 list of section offsets.
1550 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1551 conditions handling signals delivered during attach or thread creation
1552 have also been fixed.
1554 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1555 From the user's standpoint, all unqualified instances of True and False
1556 are treated as the standard definitions, regardless of context.
1558 * GDB now parses C++ symbol and type names more flexibly. For
1561 template<typename T> class C { };
1564 GDB will now correctly handle all of:
1566 ptype C<char const *>
1567 ptype C<char const*>
1568 ptype C<const char *>
1569 ptype C<const char*>
1571 * New features in the GDB remote stub, gdbserver
1573 - The "--wrapper" command-line argument tells gdbserver to use a
1574 wrapper program to launch programs for debugging.
1576 - On PowerPC and S/390 targets, it is now possible to use a single
1577 gdbserver executable to debug both 32-bit and 64-bit programs.
1578 (This requires gdbserver itself to be built as a 64-bit executable.)
1580 - gdbserver uses the new noack protocol mode for TCP connections to
1581 reduce communications latency, if also supported and enabled in GDB.
1583 - Support for the sparc64-linux-gnu target is now included in
1586 - The amd64-linux build of gdbserver now supports debugging both
1587 32-bit and 64-bit programs.
1589 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1590 now support hardware watchpoints, and will use them automatically
1595 GDB now has support for scripting using Python. Whether this is
1596 available is determined at configure time.
1598 New GDB commands can now be written in Python.
1600 * Ada tasking support
1602 Ada tasks can now be inspected in GDB. The following commands have
1606 Print the list of Ada tasks.
1608 Print detailed information about task number N.
1610 Print the task number of the current task.
1612 Switch the context of debugging to task number N.
1614 * Support for user-defined prefixed commands. The "define" command can
1615 add new commands to existing prefixes, e.g. "target".
1617 * Multi-inferior, multi-process debugging.
1619 GDB now has generalized support for multi-inferior debugging. See
1620 "Debugging Multiple Inferiors" in the manual for more information.
1621 Although availability still depends on target support, the command
1622 set is more uniform now. The GNU/Linux specific multi-forks support
1623 has been migrated to this new framework. This implied some user
1624 visible changes; see "New commands" and also "Removed commands"
1627 * Target descriptions can now describe the target OS ABI. See the
1628 "Target Description Format" section in the user manual for more
1631 * Target descriptions can now describe "compatible" architectures
1632 to indicate that the target can execute applications for a different
1633 architecture in addition to those for the main target architecture.
1634 See the "Target Description Format" section in the user manual for
1637 * Multi-architecture debugging.
1639 GDB now includes general supports for debugging applications on
1640 hybrid systems that use more than one single processor architecture
1641 at the same time. Each such hybrid architecture still requires
1642 specific support to be added. The only hybrid architecture supported
1643 in this version of GDB is the Cell Broadband Engine.
1645 * GDB now supports integrated debugging of Cell/B.E. applications that
1646 use both the PPU and SPU architectures. To enable support for hybrid
1647 Cell/B.E. debugging, you need to configure GDB to support both the
1648 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1649 --enable-targets configure option.
1651 * Non-stop mode debugging.
1653 For some targets, GDB now supports an optional mode of operation in
1654 which you can examine stopped threads while other threads continue
1655 to execute freely. This is referred to as non-stop mode, with the
1656 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1657 section in the user manual for more information.
1659 To be able to support remote non-stop debugging, a remote stub needs
1660 to implement the non-stop mode remote protocol extensions, as
1661 described in the "Remote Non-Stop" section of the user manual. The
1662 GDB remote stub, gdbserver, has been adjusted to support these
1663 extensions on linux targets.
1665 * New commands (for set/show, see "New options" below)
1667 catch syscall [NAME(S) | NUMBER(S)]
1668 Catch system calls. Arguments, which should be names of system
1669 calls or their numbers, mean catch only those syscalls. Without
1670 arguments, every syscall will be caught. When the inferior issues
1671 any of the specified syscalls, GDB will stop and announce the system
1672 call, both when it is called and when its call returns. This
1673 feature is currently available with a native GDB running on the
1674 Linux Kernel, under the following architectures: x86, x86_64,
1675 PowerPC and PowerPC64.
1677 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1679 Search memory for a sequence of bytes.
1681 maint set python print-stack
1682 maint show python print-stack
1683 Show a stack trace when an error is encountered in a Python script.
1686 Invoke CODE by passing it to the Python interpreter.
1691 These allow macros to be defined, undefined, and listed
1695 Show operating system information about processes.
1698 List the inferiors currently under GDB's control.
1701 Switch focus to inferior number NUM.
1704 Detach from inferior number NUM.
1707 Kill inferior number NUM.
1711 set spu stop-on-load
1712 show spu stop-on-load
1713 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1715 set spu auto-flush-cache
1716 show spu auto-flush-cache
1717 Control whether to automatically flush the software-managed cache
1718 during Cell/B.E. debugging.
1720 set sh calling-convention
1721 show sh calling-convention
1722 Control the calling convention used when calling SH target functions.
1725 show debug timestamp
1726 Control display of timestamps with GDB debugging output.
1728 set disassemble-next-line
1729 show disassemble-next-line
1730 Control display of disassembled source lines or instructions when
1733 set remote noack-packet
1734 show remote noack-packet
1735 Set/show the use of remote protocol QStartNoAckMode packet. See above
1736 under "New remote packets."
1738 set remote query-attached-packet
1739 show remote query-attached-packet
1740 Control use of remote protocol `qAttached' (query-attached) packet.
1742 set remote read-siginfo-object
1743 show remote read-siginfo-object
1744 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1747 set remote write-siginfo-object
1748 show remote write-siginfo-object
1749 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1752 set remote reverse-continue
1753 show remote reverse-continue
1754 Control use of remote protocol 'bc' (reverse-continue) packet.
1756 set remote reverse-step
1757 show remote reverse-step
1758 Control use of remote protocol 'bs' (reverse-step) packet.
1760 set displaced-stepping
1761 show displaced-stepping
1762 Control displaced stepping mode. Displaced stepping is a way to
1763 single-step over breakpoints without removing them from the debuggee.
1764 Also known as "out-of-line single-stepping".
1767 show debug displaced
1768 Control display of debugging info for displaced stepping.
1770 maint set internal-error
1771 maint show internal-error
1772 Control what GDB does when an internal error is detected.
1774 maint set internal-warning
1775 maint show internal-warning
1776 Control what GDB does when an internal warning is detected.
1781 Use a wrapper program to launch programs for debugging.
1783 set multiple-symbols (all|ask|cancel)
1784 show multiple-symbols
1785 The value of this variable can be changed to adjust the debugger behavior
1786 when an expression or a breakpoint location contains an ambiguous symbol
1787 name (an overloaded function name, for instance).
1789 set breakpoint always-inserted
1790 show breakpoint always-inserted
1791 Keep breakpoints always inserted in the target, as opposed to inserting
1792 them when resuming the target, and removing them when the target stops.
1793 This option can improve debugger performance on slow remote targets.
1795 set arm fallback-mode (arm|thumb|auto)
1796 show arm fallback-mode
1797 set arm force-mode (arm|thumb|auto)
1799 These commands control how ARM GDB determines whether instructions
1800 are ARM or Thumb. The default for both settings is auto, which uses
1801 the current CPSR value for instructions without symbols; previous
1802 versions of GDB behaved as if "set arm fallback-mode arm".
1804 set disable-randomization
1805 show disable-randomization
1806 Standalone programs run with the virtual address space randomization enabled
1807 by default on some platforms. This option keeps the addresses stable across
1808 multiple debugging sessions.
1812 Control whether other threads are stopped or not when some thread hits
1817 Requests that asynchronous execution is enabled in the target, if available.
1818 In this case, it's possible to resume target in the background, and interact
1819 with GDB while the target is running. "show target-async" displays the
1820 current state of asynchronous execution of the target.
1822 set target-wide-charset
1823 show target-wide-charset
1824 The target-wide-charset is the name of the character set that GDB
1825 uses when printing characters whose type is wchar_t.
1827 set tcp auto-retry (on|off)
1829 set tcp connect-timeout
1830 show tcp connect-timeout
1831 These commands allow GDB to retry failed TCP connections to a remote stub
1832 with a specified timeout period; this is useful if the stub is launched
1833 in parallel with GDB but may not be ready to accept connections immediately.
1835 set libthread-db-search-path
1836 show libthread-db-search-path
1837 Control list of directories which GDB will search for appropriate
1840 set schedule-multiple (on|off)
1841 show schedule-multiple
1842 Allow GDB to resume all threads of all processes or only threads of
1843 the current process.
1847 Use more aggressive caching for accesses to the stack. This improves
1848 performance of remote debugging (particularly backtraces) without
1849 affecting correctness.
1851 set interactive-mode (on|off|auto)
1852 show interactive-mode
1853 Control whether GDB runs in interactive mode (on) or not (off).
1854 When in interactive mode, GDB waits for the user to answer all
1855 queries. Otherwise, GDB does not wait and assumes the default
1856 answer. When set to auto (the default), GDB determines which
1857 mode to use based on the stdin settings.
1862 For program forks, this is replaced by the new more generic `info
1863 inferiors' command. To list checkpoints, you can still use the
1864 `info checkpoints' command, which was an alias for the `info forks'
1868 Replaced by the new `inferior' command. To switch between
1869 checkpoints, you can still use the `restart' command, which was an
1870 alias for the `fork' command.
1873 This is removed, since some targets don't have a notion of
1874 processes. To switch between processes, you can still use the
1875 `inferior' command using GDB's own inferior number.
1878 For program forks, this is replaced by the new more generic `kill
1879 inferior' command. To delete a checkpoint, you can still use the
1880 `delete checkpoint' command, which was an alias for the `delete
1884 For program forks, this is replaced by the new more generic `detach
1885 inferior' command. To detach a checkpoint, you can still use the
1886 `detach checkpoint' command, which was an alias for the `detach
1889 * New native configurations
1891 x86/x86_64 Darwin i[34567]86-*-darwin*
1893 x86_64 MinGW x86_64-*-mingw*
1897 Lattice Mico32 lm32-*
1898 x86 DICOS i[34567]86-*-dicos*
1899 x86_64 DICOS x86_64-*-dicos*
1902 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1903 (mingw32ce) debugging.
1909 These commands were actually not implemented on any target.
1911 *** Changes in GDB 6.8
1913 * New native configurations
1915 NetBSD/hppa hppa*-*netbsd*
1916 Xtensa GNU/Linux xtensa*-*-linux*
1920 NetBSD/hppa hppa*-*-netbsd*
1921 Xtensa GNU/Lunux xtensa*-*-linux*
1923 * Change in command line behavior -- corefiles vs. process ids.
1925 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1926 attaching to process NUMBER fails, GDB no longer attempts to open a
1927 core file named NUMBER. Attaching to a program using the -c option
1928 is no longer supported. Instead, use the '-p' or '--pid' options.
1930 * GDB can now be built as a native debugger for debugging Windows x86
1931 (mingw32) Portable Executable (PE) programs.
1933 * Pending breakpoints no longer change their number when their address
1936 * GDB now supports breakpoints with multiple locations,
1937 including breakpoints on C++ constructors, inside C++ templates,
1938 and in inlined functions.
1940 * GDB's ability to debug optimized code has been improved. GDB more
1941 accurately identifies function bodies and lexical blocks that occupy
1942 more than one contiguous range of addresses.
1944 * Target descriptions can now describe registers for PowerPC.
1946 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1947 registers on PowerPC targets.
1949 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1950 targets even when the libthread_db library is not available.
1952 * The GDB remote stub, gdbserver, now supports the new file transfer
1953 commands (remote put, remote get, and remote delete).
1955 * The GDB remote stub, gdbserver, now supports run and attach in
1956 extended-remote mode.
1958 * hppa*64*-*-hpux11* target broken
1959 The debugger is unable to start a program and fails with the following
1960 error: "Error trying to get information about dynamic linker".
1961 The gdb-6.7 release is also affected.
1963 * GDB now supports the --enable-targets= configure option to allow
1964 building a single GDB executable that supports multiple remote
1965 target architectures.
1967 * GDB now supports debugging C and C++ programs which use the
1968 Decimal Floating Point extension. In addition, the PowerPC target
1969 now has a set of pseudo-registers to inspect decimal float values
1970 stored in two consecutive float registers.
1972 * The -break-insert MI command can optionally create pending
1975 * Improved support for debugging Ada
1976 Many improvements to the Ada language support have been made. These
1978 - Better support for Ada2005 interface types
1979 - Improved handling of arrays and slices in general
1980 - Better support for Taft-amendment types
1981 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1983 - Improved command completion in Ada
1986 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1991 set print frame-arguments (all|scalars|none)
1992 show print frame-arguments
1993 The value of this variable can be changed to control which argument
1994 values should be printed by the debugger when displaying a frame.
1999 Transfer files to and from a remote target, and delete remote files.
2006 Transfer files to and from a remote target, and delete remote files.
2008 * New remote packets
2015 Open, close, read, write, and delete files on the remote system.
2018 Attach to an existing process on the remote system, in extended-remote
2022 Run a new process on the remote system, in extended-remote mode.
2024 *** Changes in GDB 6.7
2026 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2027 bfd, libiberty and opcodes, as revealed by static analysis donated by
2028 Coverity, Inc. (http://scan.coverity.com).
2030 * When looking up multiply-defined global symbols, GDB will now prefer the
2031 symbol definition in the current shared library if it was built using the
2032 -Bsymbolic linker option.
2034 * When the Text User Interface (TUI) is not configured, GDB will now
2035 recognize the -tui command-line option and print a message that the TUI
2038 * The GDB remote stub, gdbserver, now has lower overhead for high
2039 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2041 * GDB for MIPS targets now autodetects whether a remote target provides
2042 32-bit or 64-bit register values.
2044 * Support for C++ member pointers has been improved.
2046 * GDB now understands XML target descriptions, which specify the
2047 target's overall architecture. GDB can read a description from
2048 a local file or over the remote serial protocol.
2050 * Vectors of single-byte data use a new integer type which is not
2051 automatically displayed as character or string data.
2053 * The /s format now works with the print command. It displays
2054 arrays of single-byte integers and pointers to single-byte integers
2057 * Target descriptions can now describe target-specific registers,
2058 for architectures which have implemented the support (currently
2059 only ARM, M68K, and MIPS).
2061 * GDB and the GDB remote stub, gdbserver, now support the XScale
2064 * The GDB remote stub, gdbserver, has been updated to support
2065 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2066 has been rewritten to use the standard GDB remote protocol.
2068 * GDB can now step into C++ functions which are called through thunks.
2070 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2072 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2073 layout. It also supports a TextSeg= and DataSeg= response when only
2074 segment base addresses (rather than offsets) are available.
2076 * The /i format now outputs any trailing branch delay slot instructions
2077 immediately following the last instruction within the count specified.
2079 * The GDB remote protocol "T" stop reply packet now supports a
2080 "library" response. Combined with the new "qXfer:libraries:read"
2081 packet, this response allows GDB to debug shared libraries on targets
2082 where the operating system manages the list of loaded libraries (e.g.
2083 Windows and SymbianOS).
2085 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2086 (DLLs) on Windows and Windows CE targets.
2088 * GDB now supports a faster verification that a .debug file matches its binary
2089 according to its build-id signature, if the signature is present.
2095 Enable or disable hardware flow control (RTS/CTS) on the serial port
2096 when debugging using remote targets.
2098 set mem inaccessible-by-default
2099 show mem inaccessible-by-default
2100 If the target supplies a memory map, for instance via the remote
2101 protocol's "qXfer:memory-map:read" packet, setting this variable
2102 prevents GDB from accessing memory outside the memory map. This
2103 is useful for targets with memory mapped registers or which react
2104 badly to accesses of unmapped address space.
2106 set breakpoint auto-hw
2107 show breakpoint auto-hw
2108 If the target supplies a memory map, for instance via the remote
2109 protocol's "qXfer:memory-map:read" packet, setting this variable
2110 lets GDB use hardware breakpoints automatically for memory regions
2111 where it can not use software breakpoints. This covers both the
2112 "break" command and internal breakpoints used for other commands
2113 including "next" and "finish".
2116 catch exception unhandled
2117 Stop the program execution when Ada exceptions are raised.
2120 Stop the program execution when an Ada assertion failed.
2124 Set an alternate system root for target files. This is a more
2125 general version of "set solib-absolute-prefix", which is now
2126 an alias to "set sysroot".
2129 Provide extended SPU facility status information. This set of
2130 commands is available only when debugging the Cell/B.E. SPU
2133 * New native configurations
2135 OpenBSD/sh sh*-*openbsd*
2138 unset tdesc filename
2140 Use the specified local file as an XML target description, and do
2141 not query the target for its built-in description.
2145 OpenBSD/sh sh*-*-openbsd*
2146 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2147 Toshiba Media Processor mep-elf
2149 * New remote packets
2152 Ignore the specified signals; pass them directly to the debugged program
2153 without stopping other threads or reporting them to GDB.
2155 qXfer:features:read:
2156 Read an XML target description from the target, which describes its
2161 Read or write contents of an spufs file on the target system. These
2162 packets are available only on the Cell/B.E. SPU architecture.
2164 qXfer:libraries:read:
2165 Report the loaded shared libraries. Combined with new "T" packet
2166 response, this packet allows GDB to debug shared libraries on
2167 targets where the operating system manages the list of loaded
2168 libraries (e.g. Windows and SymbianOS).
2172 Support for these obsolete configurations has been removed.
2180 i[34567]86-*-lynxos*
2181 i[34567]86-*-netware*
2182 i[34567]86-*-sco3.2v5*
2183 i[34567]86-*-sco3.2v4*
2185 i[34567]86-*-sysv4.2*
2188 i[34567]86-*-unixware2*
2189 i[34567]86-*-unixware*
2198 * Other removed features
2205 Various m68k-only ROM monitors.
2212 Various Renesas ROM monitors and debugging interfaces for SH and
2217 Support for a Macraigor serial interface to on-chip debugging.
2218 GDB does not directly support the newer parallel or USB
2223 A debug information format. The predecessor to DWARF 2 and
2224 DWARF 3, which are still supported.
2226 Support for the HP aCC compiler on HP-UX/PA-RISC
2228 SOM-encapsulated symbolic debugging information, automatic
2229 invocation of pxdb, and the aCC custom C++ ABI. This does not
2230 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2231 with aCC can still be debugged on an assembly level.
2233 MIPS ".pdr" sections
2235 A MIPS-specific format used to describe stack frame layout
2236 in debugging information.
2240 GDB could work with an older version of Guile to debug
2241 the interpreter and Scheme programs running in it.
2243 set mips stack-arg-size
2244 set mips saved-gpreg-size
2246 Use "set mips abi" to control parameter passing for MIPS.
2248 *** Changes in GDB 6.6
2253 Cell Broadband Engine SPU spu-elf
2255 * GDB can now be configured as a cross-debugger targeting native Windows
2256 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2257 running on a Windows system over TCP/IP to debug Windows programs.
2259 * The GDB remote stub, gdbserver, has been updated to support Windows and
2260 Cygwin debugging. Both single-threaded and multi-threaded programs are
2263 * The "set trust-readonly-sections" command works again. This command was
2264 broken in GDB 6.3, 6.4, and 6.5.
2266 * The "load" command now supports writing to flash memory, if the remote
2267 stub provides the required support.
2269 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2270 longer requires symbolic debug information (e.g. DWARF-2).
2275 unset substitute-path
2276 show substitute-path
2277 Manage a list of substitution rules that GDB uses to rewrite the name
2278 of the directories where the sources are located. This can be useful
2279 for instance when the sources were moved to a different location
2280 between compilation and debugging.
2284 Print each CLI command as it is executed. Each command is prefixed with
2285 a number of `+' symbols representing the nesting depth.
2286 The source command now has a `-v' option to enable the same feature.
2290 The ARM Demon monitor support (RDP protocol, "target rdp").
2292 Kernel Object Display, an embedded debugging feature which only worked with
2293 an obsolete version of Cisco IOS.
2295 The 'set download-write-size' and 'show download-write-size' commands.
2297 * New remote packets
2300 Tell a stub about GDB client features, and request remote target features.
2301 The first feature implemented is PacketSize, which allows the target to
2302 specify the size of packets it can handle - to minimize the number of
2303 packets required and improve performance when connected to a remote
2307 Fetch an OS auxilliary vector from the remote stub. This packet is a
2308 more efficient replacement for qPart:auxv:read.
2310 qXfer:memory-map:read:
2311 Fetch a memory map from the remote stub, including information about
2312 RAM, ROM, and flash memory devices.
2317 Erase and program a flash memory device.
2319 * Removed remote packets
2322 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2323 used it, and only gdbserver implemented it.
2325 *** Changes in GDB 6.5
2329 Renesas M32C/M16C m32c-elf
2331 Morpho Technologies ms1 ms1-elf
2335 init-if-undefined Initialize a convenience variable, but
2336 only if it doesn't already have a value.
2338 The following commands are presently only implemented for native GNU/Linux:
2340 checkpoint Save a snapshot of the program state.
2342 restart <n> Return the program state to a
2343 previously saved state.
2345 info checkpoints List currently saved checkpoints.
2347 delete-checkpoint <n> Delete a previously saved checkpoint.
2349 set|show detach-on-fork Tell gdb whether to detach from a newly
2350 forked process, or to keep debugging it.
2352 info forks List forks of the user program that
2353 are available to be debugged.
2355 fork <n> Switch to debugging one of several
2356 forks of the user program that are
2357 available to be debugged.
2359 delete-fork <n> Delete a fork from the list of forks
2360 that are available to be debugged (and
2361 kill the forked process).
2363 detach-fork <n> Delete a fork from the list of forks
2364 that are available to be debugged (and
2365 allow the process to continue).
2369 Morpho Technologies ms2 ms1-elf
2371 * Improved Windows host support
2373 GDB now builds as a cross debugger hosted on i686-mingw32, including
2374 native console support, and remote communications using either
2375 network sockets or serial ports.
2377 * Improved Modula-2 language support
2379 GDB can now print most types in the Modula-2 syntax. This includes:
2380 basic types, set types, record types, enumerated types, range types,
2381 pointer types and ARRAY types. Procedure var parameters are correctly
2382 printed and hexadecimal addresses and character constants are also
2383 written in the Modula-2 syntax. Best results can be obtained by using
2384 GNU Modula-2 together with the -gdwarf-2 command line option.
2388 The ARM rdi-share module.
2390 The Netware NLM debug server.
2392 *** Changes in GDB 6.4
2394 * New native configurations
2396 OpenBSD/arm arm*-*-openbsd*
2397 OpenBSD/mips64 mips64-*-openbsd*
2401 Morpho Technologies ms1 ms1-elf
2403 * New command line options
2405 --batch-silent As for --batch, but totally silent.
2406 --return-child-result The debugger will exist with the same value
2407 the child (debugged) program exited with.
2408 --eval-command COMMAND, -ex COMMAND
2409 Execute a single GDB CLI command. This may be
2410 specified multiple times and in conjunction
2411 with the --command (-x) option.
2413 * Deprecated commands removed
2415 The following commands, that were deprecated in 2000, have been
2419 set|show arm disassembly-flavor set|show arm disassembler
2420 othernames set arm disassembler
2421 set|show remotedebug set|show debug remote
2422 set|show archdebug set|show debug arch
2423 set|show eventdebug set|show debug event
2426 * New BSD user-level threads support
2428 It is now possible to debug programs using the user-level threads
2429 library on OpenBSD and FreeBSD. Currently supported (target)
2432 FreeBSD/amd64 x86_64-*-freebsd*
2433 FreeBSD/i386 i386-*-freebsd*
2434 OpenBSD/i386 i386-*-openbsd*
2436 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2437 are not yet supported.
2439 * New support for Matsushita MN10300 w/sim added
2440 (Work in progress). mn10300-elf.
2442 * REMOVED configurations and files
2444 VxWorks and the XDR protocol *-*-vxworks
2445 Motorola MCORE mcore-*-*
2446 National Semiconductor NS32000 ns32k-*-*
2448 * New "set print array-indexes" command
2450 After turning this setting "on", GDB prints the index of each element
2451 when displaying arrays. The default is "off" to preserve the previous
2454 * VAX floating point support
2456 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2458 * User-defined command support
2460 In addition to using $arg0..$arg9 for argument passing, it is now possible
2461 to use $argc to determine now many arguments have been passed. See the
2462 section on user-defined commands in the user manual for more information.
2464 *** Changes in GDB 6.3:
2466 * New command line option
2468 GDB now accepts -l followed by a number to set the timeout for remote
2471 * GDB works with GCC -feliminate-dwarf2-dups
2473 GDB now supports a more compact representation of DWARF-2 debug
2474 information using DW_FORM_ref_addr references. These are produced
2475 by GCC with the option -feliminate-dwarf2-dups and also by some
2476 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2477 to use -feliminate-dwarf2-dups.
2479 * Internationalization
2481 When supported by the host system, GDB will be built with
2482 internationalization (libintl). The task of marking up the sources is
2483 continued, we're looking forward to our first translation.
2487 Initial support for debugging programs compiled with the GNAT
2488 implementation of the Ada programming language has been integrated
2489 into GDB. In this release, support is limited to expression evaluation.
2491 * New native configurations
2493 GNU/Linux/m32r m32r-*-linux-gnu
2497 GDB's remote protocol now includes support for the 'p' packet. This
2498 packet is used to fetch individual registers from a remote inferior.
2500 * END-OF-LIFE registers[] compatibility module
2502 GDB's internal register infrastructure has been completely rewritten.
2503 The new infrastructure making possible the implementation of key new
2504 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2507 GDB 6.3 will be the last release to include the the registers[]
2508 compatibility module that allowed out-of-date configurations to
2509 continue to work. This change directly impacts the following
2519 powerpc bdm protocol
2521 Unless there is activity to revive these configurations, they will be
2522 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2524 * OBSOLETE configurations and files
2526 Configurations that have been declared obsolete in this release have
2527 been commented out. Unless there is activity to revive these
2528 configurations, the next release of GDB will have their sources
2529 permanently REMOVED.
2538 *** Changes in GDB 6.2.1:
2540 * MIPS `break main; run' gave an heuristic-fence-post warning
2542 When attempting to run even a simple program, a warning about
2543 heuristic-fence-post being hit would be reported. This problem has
2546 * MIPS IRIX 'long double' crashed GDB
2548 When examining a long double variable, GDB would get a segmentation
2549 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2550 IRIX long double values).
2554 A bug in the VAX stack code was causing problems with the "next"
2555 command. This problem has been fixed.
2557 *** Changes in GDB 6.2:
2559 * Fix for ``many threads''
2561 On GNU/Linux systems that use the NPTL threads library, a program
2562 rapidly creating and deleting threads would confuse GDB leading to the
2565 ptrace: No such process.
2566 thread_db_get_info: cannot get thread info: generic error
2568 This problem has been fixed.
2570 * "-async" and "-noasync" options removed.
2572 Support for the broken "-noasync" option has been removed (it caused
2575 * New ``start'' command.
2577 This command runs the program until the begining of the main procedure.
2579 * New BSD Kernel Data Access Library (libkvm) interface
2581 Using ``target kvm'' it is now possible to debug kernel core dumps and
2582 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2583 platforms. Currently supported (native-only) configurations are:
2585 FreeBSD/amd64 x86_64-*-freebsd*
2586 FreeBSD/i386 i?86-*-freebsd*
2587 NetBSD/i386 i?86-*-netbsd*
2588 NetBSD/m68k m68*-*-netbsd*
2589 NetBSD/sparc sparc-*-netbsd*
2590 OpenBSD/amd64 x86_64-*-openbsd*
2591 OpenBSD/i386 i?86-*-openbsd*
2592 OpenBSD/m68k m68*-openbsd*
2593 OpenBSD/sparc sparc-*-openbsd*
2595 * Signal trampoline code overhauled
2597 Many generic problems with GDB's signal handling code have been fixed.
2598 These include: backtraces through non-contiguous stacks; recognition
2599 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2600 call; backtrace through a signal trampoline; step into and out of
2601 signal handlers; and single-stepping in the signal trampoline.
2603 Please note that kernel bugs are a limiting factor here. These
2604 features have been shown to work on an s390 GNU/Linux system that
2605 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2607 * Cygwin support for DWARF 2 added.
2609 * New native configurations
2611 GNU/Linux/hppa hppa*-*-linux*
2612 OpenBSD/hppa hppa*-*-openbsd*
2613 OpenBSD/m68k m68*-*-openbsd*
2614 OpenBSD/m88k m88*-*-openbsd*
2615 OpenBSD/powerpc powerpc-*-openbsd*
2616 NetBSD/vax vax-*-netbsd*
2617 OpenBSD/vax vax-*-openbsd*
2619 * END-OF-LIFE frame compatibility module
2621 GDB's internal frame infrastructure has been completely rewritten.
2622 The new infrastructure making it possible to support key new features
2623 including DWARF 2 Call Frame Information. To aid in the task of
2624 migrating old configurations to this new infrastructure, a
2625 compatibility module, that allowed old configurations to continue to
2626 work, was also included.
2628 GDB 6.2 will be the last release to include this frame compatibility
2629 module. This change directly impacts the following configurations:
2639 Unless there is activity to revive these configurations, they will be
2640 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2642 * REMOVED configurations and files
2644 Sun 3, running SunOS 3 m68*-*-sunos3*
2645 Sun 3, running SunOS 4 m68*-*-sunos4*
2646 Sun 2, running SunOS 3 m68000-*-sunos3*
2647 Sun 2, running SunOS 4 m68000-*-sunos4*
2648 Motorola 680x0 running LynxOS m68*-*-lynxos*
2649 AT&T 3b1/Unix pc m68*-att-*
2650 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2651 decstation mips-dec-* mips-little-*
2652 riscos mips-*-riscos* mips-*-sysv*
2653 sonymips mips-sony-*
2654 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2656 *** Changes in GDB 6.1.1:
2658 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2660 The TUI (Text-mode User Interface) is now built as part of a default
2661 GDB configuration. It is enabled by either selecting the TUI with the
2662 command line option "-i=tui" or by running the separate "gdbtui"
2663 program. For more information on the TUI, see the manual "Debugging
2666 * Pending breakpoint support (also included in GDB 6.1)
2668 Support has been added to allow you to specify breakpoints in shared
2669 libraries that have not yet been loaded. If a breakpoint location
2670 cannot be found, and the "breakpoint pending" option is set to auto,
2671 GDB queries you if you wish to make the breakpoint pending on a future
2672 shared-library load. If and when GDB resolves the breakpoint symbol,
2673 the pending breakpoint is removed as one or more regular breakpoints
2676 Pending breakpoints are very useful for GCJ Java debugging.
2678 * Fixed ISO-C build problems
2680 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2681 non ISO-C code that stopped them being built using a more strict ISO-C
2682 compiler (e.g., IBM's C compiler).
2684 * Fixed build problem on IRIX 5
2686 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2687 wasn't able to compile compile on an IRIX 5 system.
2689 * Added execute permission to gdb/gdbserver/configure
2691 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2692 permission. This bug would cause configure to fail on a number of
2693 systems (Solaris, IRIX). Ref: server/519.
2695 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2697 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2698 has been updated to use constant array sizes.
2700 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2702 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2703 its generated DWARF Call Frame Info. This encoding was causing GDB to
2704 panic, that panic has been fixed. Ref: gdb/1628.
2706 * Fixed a problem when examining parameters in shared library code.
2708 When examining parameters in optimized shared library code generated
2709 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2710 not available''. GDB now correctly displays the variable's value.
2712 *** Changes in GDB 6.1:
2714 * Removed --with-mmalloc
2716 Support for the mmalloc memory manager has been removed, as it
2717 conflicted with the internal gdb byte cache.
2719 * Changes in AMD64 configurations
2721 The AMD64 target now includes the %cs and %ss registers. As a result
2722 the AMD64 remote protocol has changed; this affects the floating-point
2723 and SSE registers. If you rely on those registers for your debugging,
2724 you should upgrade gdbserver on the remote side.
2726 * Revised SPARC target
2728 The SPARC target has been completely revised, incorporating the
2729 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2730 support for LynxOS and SunOS 4 has been dropped. Calling functions
2731 from within GDB on operating systems with a non-executable stack
2732 (Solaris, OpenBSD) now works.
2736 GDB has a new C++ demangler which does a better job on the mangled
2737 names generated by current versions of g++. It also runs faster, so
2738 with this and other changes gdb should now start faster on large C++
2741 * DWARF 2 Location Expressions
2743 GDB support for location expressions has been extended to support function
2744 arguments and frame bases. Older versions of GDB could crash when they
2747 * C++ nested types and namespaces
2749 GDB's support for nested types and namespaces in C++ has been
2750 improved, especially if you use the DWARF 2 debugging format. (This
2751 is the default for recent versions of GCC on most platforms.)
2752 Specifically, if you have a class "Inner" defined within a class or
2753 namespace "Outer", then GDB realizes that the class's name is
2754 "Outer::Inner", not simply "Inner". This should greatly reduce the
2755 frequency of complaints about not finding RTTI symbols. In addition,
2756 if you are stopped at inside of a function defined within a namespace,
2757 GDB modifies its name lookup accordingly.
2759 * New native configurations
2761 NetBSD/amd64 x86_64-*-netbsd*
2762 OpenBSD/amd64 x86_64-*-openbsd*
2763 OpenBSD/alpha alpha*-*-openbsd*
2764 OpenBSD/sparc sparc-*-openbsd*
2765 OpenBSD/sparc64 sparc64-*-openbsd*
2767 * New debugging protocols
2769 M32R with SDI protocol m32r-*-elf*
2771 * "set prompt-escape-char" command deleted.
2773 The command "set prompt-escape-char" has been deleted. This command,
2774 and its very obscure effet on GDB's prompt, was never documented,
2775 tested, nor mentioned in the NEWS file.
2777 * OBSOLETE configurations and files
2779 Configurations that have been declared obsolete in this release have
2780 been commented out. Unless there is activity to revive these
2781 configurations, the next release of GDB will have their sources
2782 permanently REMOVED.
2784 Sun 3, running SunOS 3 m68*-*-sunos3*
2785 Sun 3, running SunOS 4 m68*-*-sunos4*
2786 Sun 2, running SunOS 3 m68000-*-sunos3*
2787 Sun 2, running SunOS 4 m68000-*-sunos4*
2788 Motorola 680x0 running LynxOS m68*-*-lynxos*
2789 AT&T 3b1/Unix pc m68*-att-*
2790 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2791 decstation mips-dec-* mips-little-*
2792 riscos mips-*-riscos* mips-*-sysv*
2793 sonymips mips-sony-*
2794 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2796 * REMOVED configurations and files
2798 SGI Irix-4.x mips-sgi-irix4 or iris4
2799 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2800 Z8000 simulator z8k-zilog-none or z8ksim
2801 Matsushita MN10200 w/simulator mn10200-*-*
2802 H8/500 simulator h8500-hitachi-hms or h8500hms
2803 HP/PA running BSD hppa*-*-bsd*
2804 HP/PA running OSF/1 hppa*-*-osf*
2805 HP/PA Pro target hppa*-*-pro*
2806 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2807 386BSD i[3456]86-*-bsd*
2808 Sequent family i[3456]86-sequent-sysv4*
2809 i[3456]86-sequent-sysv*
2810 i[3456]86-sequent-bsd*
2811 SPARC running LynxOS sparc-*-lynxos*
2812 SPARC running SunOS 4 sparc-*-sunos4*
2813 Tsqware Sparclet sparclet-*-*
2814 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2816 *** Changes in GDB 6.0:
2820 Support for debugging the Objective-C programming language has been
2821 integrated into GDB.
2823 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2825 DWARF 2's Call Frame Information makes available compiler generated
2826 information that more exactly describes the program's run-time stack.
2827 By using this information, GDB is able to provide more robust stack
2830 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2831 have been updated to use a new backtrace mechanism which includes
2832 DWARF 2 CFI support.
2836 GDB's remote protocol has been extended to include support for hosted
2837 file I/O (where the remote target uses GDB's file system). See GDB's
2838 remote protocol documentation for details.
2840 * All targets using the new architecture framework.
2842 All of GDB's targets have been updated to use the new internal
2843 architecture framework. The way is now open for future GDB releases
2844 to include cross-architecture native debugging support (i386 on amd64,
2847 * GNU/Linux's Thread Local Storage (TLS)
2849 GDB now includes support for for the GNU/Linux implementation of
2850 per-thread variables.
2852 * GNU/Linux's Native POSIX Thread Library (NPTL)
2854 GDB's thread code has been updated to work with either the new
2855 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2857 * Separate debug info.
2859 GDB, in conjunction with BINUTILS, now supports a mechanism for
2860 automatically loading debug information from a separate file. Instead
2861 of shipping full debug and non-debug versions of system libraries,
2862 system integrators can now instead ship just the stripped libraries
2863 and optional debug files.
2865 * DWARF 2 Location Expressions
2867 DWARF 2 Location Expressions allow the compiler to more completely
2868 describe the location of variables (even in optimized code) to the
2871 GDB now includes preliminary support for location expressions (support
2872 for DW_OP_piece is still missing).
2876 A number of long standing bugs that caused GDB to die while starting a
2877 Java application have been fixed. GDB's Java support is now
2878 considered "useable".
2880 * GNU/Linux support for fork, vfork, and exec.
2882 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2883 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2886 * GDB supports logging output to a file
2888 There are two new commands, "set logging" and "show logging", which can be
2889 used to capture GDB's output to a file.
2891 * The meaning of "detach" has changed for gdbserver
2893 The "detach" command will now resume the application, as documented. To
2894 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2897 * d10v, m68hc11 `regs' command deprecated
2899 The `info registers' command has been updated so that it displays the
2900 registers using a format identical to the old `regs' command.
2904 A new command, "maint set profile on/off", has been added. This command can
2905 be used to enable or disable profiling while running GDB, to profile a
2906 session or a set of commands. In addition there is a new configure switch,
2907 "--enable-profiling", which will cause GDB to be compiled with profiling
2908 data, for more informative profiling results.
2910 * Default MI syntax changed to "mi2".
2912 The default MI (machine interface) syntax, enabled by the command line
2913 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2914 "mi1", can be enabled by specifying the option "-i=mi1".
2916 Support for the original "mi0" syntax (included in GDB 5.0) has been
2919 Fix for gdb/192: removed extraneous space when displaying frame level.
2920 Fix for gdb/672: update changelist is now output in mi list format.
2921 Fix for gdb/702: a -var-assign that updates the value now shows up
2922 in a subsequent -var-update.
2924 * New native configurations.
2926 FreeBSD/amd64 x86_64-*-freebsd*
2928 * Multi-arched targets.
2930 HP/PA HPUX11 hppa*-*-hpux*
2931 Renesas M32R/D w/simulator m32r-*-elf*
2933 * OBSOLETE configurations and files
2935 Configurations that have been declared obsolete in this release have
2936 been commented out. Unless there is activity to revive these
2937 configurations, the next release of GDB will have their sources
2938 permanently REMOVED.
2940 Z8000 simulator z8k-zilog-none or z8ksim
2941 Matsushita MN10200 w/simulator mn10200-*-*
2942 H8/500 simulator h8500-hitachi-hms or h8500hms
2943 HP/PA running BSD hppa*-*-bsd*
2944 HP/PA running OSF/1 hppa*-*-osf*
2945 HP/PA Pro target hppa*-*-pro*
2946 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2947 Sequent family i[3456]86-sequent-sysv4*
2948 i[3456]86-sequent-sysv*
2949 i[3456]86-sequent-bsd*
2950 Tsqware Sparclet sparclet-*-*
2951 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2953 * REMOVED configurations and files
2956 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2957 IBM AIX PS/2 i[3456]86-*-aix
2958 i386 running Mach 3.0 i[3456]86-*-mach3*
2959 i386 running Mach i[3456]86-*-mach*
2960 i386 running OSF/1 i[3456]86-*osf1mk*
2961 HP/Apollo 68k Family m68*-apollo*-sysv*,
2963 m68*-hp-bsd*, m68*-hp-hpux*
2964 Argonaut Risc Chip (ARC) arc-*-*
2965 Mitsubishi D30V d30v-*-*
2966 Fujitsu FR30 fr30-*-elf*
2967 OS/9000 i[34]86-*-os9k
2968 I960 with MON960 i960-*-coff
2970 * MIPS $fp behavior changed
2972 The convenience variable $fp, for the MIPS, now consistently returns
2973 the address of the current frame's base. Previously, depending on the
2974 context, $fp could refer to either $sp or the current frame's base
2975 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2976 The GNU Source-Level Debugger''.
2978 *** Changes in GDB 5.3:
2980 * GNU/Linux shared library multi-threaded performance improved.
2982 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2983 `/proc', in preference to `ptrace' for memory reads. This may result
2984 in an improvement in the start-up time of multi-threaded, shared
2985 library applications when run under GDB. One GDB user writes: ``loads
2986 shared libs like mad''.
2988 * ``gdbserver'' now supports multi-threaded applications on some targets
2990 Support for debugging multi-threaded applications which use
2991 the GNU/Linux LinuxThreads package has been added for
2992 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2993 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2995 * GDB now supports C/C++ preprocessor macros.
2997 GDB now expands preprocessor macro invocations in C/C++ expressions,
2998 and provides various commands for showing macro definitions and how
3001 The new command `macro expand EXPRESSION' expands any macro
3002 invocations in expression, and shows the result.
3004 The new command `show macro MACRO-NAME' shows the definition of the
3005 macro named MACRO-NAME, and where it was defined.
3007 Most compilers don't include information about macros in the debugging
3008 information by default. In GCC 3.1, for example, you need to compile
3009 your program with the options `-gdwarf-2 -g3'. If the macro
3010 information is present in the executable, GDB will read it.
3012 * Multi-arched targets.
3014 DEC Alpha (partial) alpha*-*-*
3015 DEC VAX (partial) vax-*-*
3017 National Semiconductor NS32000 (partial) ns32k-*-*
3018 Motorola 68000 (partial) m68k-*-*
3019 Motorola MCORE mcore-*-*
3023 Fujitsu FRV architecture added by Red Hat frv*-*-*
3026 * New native configurations
3028 Alpha NetBSD alpha*-*-netbsd*
3029 SH NetBSD sh*-*-netbsdelf*
3030 MIPS NetBSD mips*-*-netbsd*
3031 UltraSPARC NetBSD sparc64-*-netbsd*
3033 * OBSOLETE configurations and files
3035 Configurations that have been declared obsolete in this release have
3036 been commented out. Unless there is activity to revive these
3037 configurations, the next release of GDB will have their sources
3038 permanently REMOVED.
3040 Mitsubishi D30V d30v-*-*
3041 OS/9000 i[34]86-*-os9k
3042 IBM AIX PS/2 i[3456]86-*-aix
3043 Fujitsu FR30 fr30-*-elf*
3044 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3045 Argonaut Risc Chip (ARC) arc-*-*
3046 i386 running Mach 3.0 i[3456]86-*-mach3*
3047 i386 running Mach i[3456]86-*-mach*
3048 i386 running OSF/1 i[3456]86-*osf1mk*
3049 HP/Apollo 68k Family m68*-apollo*-sysv*,
3051 m68*-hp-bsd*, m68*-hp-hpux*
3052 I960 with MON960 i960-*-coff
3054 * OBSOLETE languages
3056 CHILL, a Pascal like language used by telecommunications companies.
3058 * REMOVED configurations and files
3060 AMD 29k family via UDI a29k-amd-udi, udi29k
3061 A29K VxWorks a29k-*-vxworks
3062 AMD 29000 embedded, using EBMON a29k-none-none
3063 AMD 29000 embedded with COFF a29k-none-coff
3064 AMD 29000 embedded with a.out a29k-none-aout
3066 testsuite/gdb.hp/gdb.threads-hp/ directory
3068 * New command "set max-user-call-depth <nnn>"
3070 This command allows the user to limit the call depth of user-defined
3071 commands. The default is 1024.
3073 * Changes in FreeBSD/i386 native debugging.
3075 Support for the "generate-core-file" has been added.
3077 * New commands "dump", "append", and "restore".
3079 These commands allow data to be copied from target memory
3080 to a bfd-format or binary file (dump and append), and back
3081 from a file into memory (restore).
3083 * Improved "next/step" support on multi-processor Alpha Tru64.
3085 The previous single-step mechanism could cause unpredictable problems,
3086 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3087 of a software single-step mechanism prevents this.
3089 *** Changes in GDB 5.2.1:
3097 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3098 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3099 Fix, by Joel Brobecker imported from mainline.
3101 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3102 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3103 Fix, by Fred Fish, imported from mainline.
3105 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3106 Surprisingly enough, it works now.
3107 By Michal Ludvig, imported from mainline.
3109 i386 hardware watchpoint support:
3110 avoid misses on second run for some targets.
3111 By Pierre Muller, imported from mainline.
3113 *** Changes in GDB 5.2:
3115 * New command "set trust-readonly-sections on[off]".
3117 This command is a hint that tells gdb that read-only sections
3118 really are read-only (ie. that their contents will not change).
3119 In this mode, gdb will go to the object file rather than the
3120 target to read memory from read-only sections (such as ".text").
3121 This can be a significant performance improvement on some
3122 (notably embedded) targets.
3124 * New command "generate-core-file" (or "gcore").
3126 This new gdb command allows the user to drop a core file of the child
3127 process state at any time. So far it's been implemented only for
3128 GNU/Linux and Solaris, but should be relatively easily ported to other
3129 hosts. Argument is core file name (defaults to core.<pid>).
3131 * New command line option
3133 GDB now accepts --pid or -p followed by a process id.
3135 * Change in command line behavior -- corefiles vs. process ids.
3137 There is a subtle behavior in the way in which GDB handles
3138 command line arguments. The first non-flag argument is always
3139 a program to debug, but the second non-flag argument may either
3140 be a corefile or a process id. Previously, GDB would attempt to
3141 open the second argument as a corefile, and if that failed, would
3142 issue a superfluous error message and then attempt to attach it as
3143 a process. Now, if the second argument begins with a non-digit,
3144 it will be treated as a corefile. If it begins with a digit,
3145 GDB will attempt to attach it as a process, and if no such process
3146 is found, will then attempt to open it as a corefile.
3148 * Changes in ARM configurations.
3150 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3151 configuration is fully multi-arch.
3153 * New native configurations
3155 ARM NetBSD arm*-*-netbsd*
3156 x86 OpenBSD i[3456]86-*-openbsd*
3157 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3158 Sparc64 running FreeBSD sparc64-*-freebsd*
3162 Sanyo XStormy16 xstormy16-elf
3164 * OBSOLETE configurations and files
3166 Configurations that have been declared obsolete in this release have
3167 been commented out. Unless there is activity to revive these
3168 configurations, the next release of GDB will have their sources
3169 permanently REMOVED.
3171 AMD 29k family via UDI a29k-amd-udi, udi29k
3172 A29K VxWorks a29k-*-vxworks
3173 AMD 29000 embedded, using EBMON a29k-none-none
3174 AMD 29000 embedded with COFF a29k-none-coff
3175 AMD 29000 embedded with a.out a29k-none-aout
3177 testsuite/gdb.hp/gdb.threads-hp/ directory
3179 * REMOVED configurations and files
3181 TI TMS320C80 tic80-*-*
3183 PowerPC Solaris powerpcle-*-solaris*
3184 PowerPC Windows NT powerpcle-*-cygwin32
3185 PowerPC Netware powerpc-*-netware*
3186 Harris/CXUX m88k m88*-harris-cxux*
3187 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3188 ns32k-utek-sysv* ns32k-utek-*
3189 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3190 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3191 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3192 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3193 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3195 * Changes to command line processing
3197 The new `--args' feature can be used to specify command-line arguments
3198 for the inferior from gdb's command line.
3200 * Changes to key bindings
3202 There is a new `operate-and-get-next' function bound to `C-o'.
3204 *** Changes in GDB 5.1.1
3206 Fix compile problem on DJGPP.
3208 Fix a problem with floating-point registers on the i386 being
3211 Fix to stop GDB crashing on .debug_str debug info.
3213 Numerous documentation fixes.
3215 Numerous testsuite fixes.
3217 *** Changes in GDB 5.1:
3219 * New native configurations
3221 Alpha FreeBSD alpha*-*-freebsd*
3222 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3223 MIPS GNU/Linux mips*-*-linux*
3224 MIPS SGI Irix 6.x mips*-sgi-irix6*
3225 ia64 AIX ia64-*-aix*
3226 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3230 Motorola 68HC11 and 68HC12 m68hc11-elf
3232 UltraSparc running GNU/Linux sparc64-*-linux*
3234 * OBSOLETE configurations and files
3236 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3237 Harris/CXUX m88k m88*-harris-cxux*
3238 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3239 ns32k-utek-sysv* ns32k-utek-*
3240 TI TMS320C80 tic80-*-*
3242 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3243 PowerPC Solaris powerpcle-*-solaris*
3244 PowerPC Windows NT powerpcle-*-cygwin32
3245 PowerPC Netware powerpc-*-netware*
3246 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3247 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3248 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3249 Apple Macintosh (MPW) host N/A
3251 stuff.c (Program to stuff files into a specially prepared space in kdb)
3252 kdb-start.c (Main loop for the standalone kernel debugger)
3254 Configurations that have been declared obsolete in this release have
3255 been commented out. Unless there is activity to revive these
3256 configurations, the next release of GDB will have their sources
3257 permanently REMOVED.
3259 * REMOVED configurations and files
3261 Altos 3068 m68*-altos-*
3262 Convex c1-*-*, c2-*-*
3264 ARM RISCix arm-*-* (as host)
3268 * GDB has been converted to ISO C.
3270 GDB's source code has been converted to ISO C. In particular, the
3271 sources are fully protoized, and rely on standard headers being
3276 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3278 * The MI enabled by default.
3280 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3281 revised and enabled by default. Packages which use GDB as a debugging
3282 engine behind a UI or another front end are encouraged to switch to
3283 using the GDB/MI interface, instead of the old annotations interface
3284 which is now deprecated.
3286 * Support for debugging Pascal programs.
3288 GDB now includes support for debugging Pascal programs. The following
3289 main features are supported:
3291 - Pascal-specific data types such as sets;
3293 - automatic recognition of Pascal sources based on file-name
3296 - Pascal-style display of data types, variables, and functions;
3298 - a Pascal expression parser.
3300 However, some important features are not yet supported.
3302 - Pascal string operations are not supported at all;
3304 - there are some problems with boolean types;
3306 - Pascal type hexadecimal constants are not supported
3307 because they conflict with the internal variables format;
3309 - support for Pascal objects and classes is not full yet;
3311 - unlike Pascal, GDB is case-sensitive for symbol names.
3313 * Changes in completion.
3315 Commands such as `shell', `run' and `set args', which pass arguments
3316 to inferior programs, now complete on file names, similar to what
3317 users expect at the shell prompt.
3319 Commands which accept locations, such as `disassemble', `print',
3320 `breakpoint', `until', etc. now complete on filenames as well as
3321 program symbols. Thus, if you type "break foob TAB", and the source
3322 files linked into the programs include `foobar.c', that file name will
3323 be one of the candidates for completion. However, file names are not
3324 considered for completion after you typed a colon that delimits a file
3325 name from a name of a function in that file, as in "break foo.c:bar".
3327 `set demangle-style' completes on available demangling styles.
3329 * New platform-independent commands:
3331 It is now possible to define a post-hook for a command as well as a
3332 hook that runs before the command. For more details, see the
3333 documentation of `hookpost' in the GDB manual.
3335 * Changes in GNU/Linux native debugging.
3337 Support for debugging multi-threaded programs has been completely
3338 revised for all platforms except m68k and sparc. You can now debug as
3339 many threads as your system allows you to have.
3341 Attach/detach is supported for multi-threaded programs.
3343 Support for SSE registers was added for x86. This doesn't work for
3344 multi-threaded programs though.
3346 * Changes in MIPS configurations.
3348 Multi-arch support is enabled for all MIPS configurations.
3350 GDB can now be built as native debugger on SGI Irix 6.x systems for
3351 debugging n32 executables. (Debugging 64-bit executables is not yet
3354 * Unified support for hardware watchpoints in all x86 configurations.
3356 Most (if not all) native x86 configurations support hardware-assisted
3357 breakpoints and watchpoints in a unified manner. This support
3358 implements debug register sharing between watchpoints, which allows to
3359 put a virtually infinite number of watchpoints on the same address,
3360 and also supports watching regions up to 16 bytes with several debug
3363 The new maintenance command `maintenance show-debug-regs' toggles
3364 debugging print-outs in functions that insert, remove, and test
3365 watchpoints and hardware breakpoints.
3367 * Changes in the DJGPP native configuration.
3369 New command ``info dos sysinfo'' displays assorted information about
3370 the CPU, OS, memory, and DPMI server.
3372 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3373 display information about segment descriptors stored in GDT, LDT, and
3376 New commands ``info dos pde'' and ``info dos pte'' display entries
3377 from Page Directory and Page Tables (for now works with CWSDPMI only).
3378 New command ``info dos address-pte'' displays the Page Table entry for
3379 a given linear address.
3381 GDB can now pass command lines longer than 126 characters to the
3382 program being debugged (requires an update to the libdbg.a library
3383 which is part of the DJGPP development kit).
3385 DWARF2 debug info is now supported.
3387 It is now possible to `step' and `next' through calls to `longjmp'.
3389 * Changes in documentation.
3391 All GDB documentation was converted to GFDL, the GNU Free
3392 Documentation License.
3394 Tracepoints-related commands are now fully documented in the GDB
3397 TUI, the Text-mode User Interface, is now documented in the manual.
3399 Tracepoints-related commands are now fully documented in the GDB
3402 The "GDB Internals" manual now has an index. It also includes
3403 documentation of `ui_out' functions, GDB coding standards, x86
3404 hardware watchpoints, and memory region attributes.
3406 * GDB's version number moved to ``version.in''
3408 The Makefile variable VERSION has been replaced by the file
3409 ``version.in''. People creating GDB distributions should update the
3410 contents of this file.
3414 GUD support is now a standard part of the EMACS distribution.
3416 *** Changes in GDB 5.0:
3418 * Improved support for debugging FP programs on x86 targets
3420 Unified and much-improved support for debugging floating-point
3421 programs on all x86 targets. In particular, ``info float'' now
3422 displays the FP registers in the same format on all x86 targets, with
3423 greater level of detail.
3425 * Improvements and bugfixes in hardware-assisted watchpoints
3427 It is now possible to watch array elements, struct members, and
3428 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3429 on x86 targets no longer erroneously trigger when the address is
3432 * Improvements in the native DJGPP version of GDB
3434 The distribution now includes all the scripts and auxiliary files
3435 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3436 machines ``out of the box''.
3438 The DJGPP version can now debug programs that use signals. It is
3439 possible to catch signals that happened in the debuggee, deliver
3440 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3441 would kill the program being debugged.) Programs that hook hardware
3442 interrupts (keyboard, timer, etc.) can also be debugged.
3444 It is now possible to debug DJGPP programs that redirect their
3445 standard handles or switch them to raw (as opposed to cooked) mode, or
3446 even close them. The command ``run < foo > bar'' works as expected,
3447 and ``info terminal'' reports useful information about the debuggee's
3448 terminal, including raw/cooked mode, redirection, etc.
3450 The DJGPP version now uses termios functions for console I/O, which
3451 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3454 DOS-style file names with drive letters are now fully supported by
3457 It is now possible to debug DJGPP programs that switch their working
3458 directory. It is also possible to rerun the debuggee any number of
3459 times without restarting GDB; thus, you can use the same setup,
3460 breakpoints, etc. for many debugging sessions.
3462 * New native configurations
3464 ARM GNU/Linux arm*-*-linux*
3465 PowerPC GNU/Linux powerpc-*-linux*
3469 Motorola MCore mcore-*-*
3470 x86 VxWorks i[3456]86-*-vxworks*
3471 PowerPC VxWorks powerpc-*-vxworks*
3472 TI TMS320C80 tic80-*-*
3474 * OBSOLETE configurations
3476 Altos 3068 m68*-altos-*
3477 Convex c1-*-*, c2-*-*
3479 ARM RISCix arm-*-* (as host)
3482 Configurations that have been declared obsolete will be commented out,
3483 but the code will be left in place. If there is no activity to revive
3484 these configurations before the next release of GDB, the sources will
3485 be permanently REMOVED.
3487 * Gould support removed
3489 Support for the Gould PowerNode and NP1 has been removed.
3491 * New features for SVR4
3493 On SVR4 native platforms (such as Solaris), if you attach to a process
3494 without first loading a symbol file, GDB will now attempt to locate and
3495 load symbols from the running process's executable file.
3497 * Many C++ enhancements
3499 C++ support has been greatly improved. Overload resolution now works properly
3500 in almost all cases. RTTI support is on the way.
3502 * Remote targets can connect to a sub-program
3504 A popen(3) style serial-device has been added. This device starts a
3505 sub-process (such as a stand-alone simulator) and then communicates
3506 with that. The sub-program to run is specified using the syntax
3507 ``|<program> <args>'' vis:
3509 (gdb) set remotedebug 1
3510 (gdb) target extended-remote |mn10300-elf-sim program-args
3512 * MIPS 64 remote protocol
3514 A long standing bug in the mips64 remote protocol where by GDB
3515 expected certain 32 bit registers (ex SR) to be transfered as 32
3516 instead of 64 bits has been fixed.
3518 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3519 added to provide backward compatibility with older versions of GDB.
3521 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3523 The command ``set remotebinarydownload'' command has been replaced by
3524 ``set remote X-packet''. Other commands in ``set remote'' family
3525 include ``set remote P-packet''.
3527 * Breakpoint commands accept ranges.
3529 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3530 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3531 ``tracepoint passcount'' also accepts a range of tracepoints.
3533 * ``apropos'' command added.
3535 The ``apropos'' command searches through command names and
3536 documentation strings, printing out matches, making it much easier to
3537 try to find a command that does what you are looking for.
3541 A new machine oriented interface (MI) has been added to GDB. This
3542 interface is designed for debug environments running GDB as a separate
3543 process. This is part of the long term libGDB project. See the
3544 "GDB/MI" chapter of the GDB manual for further information. It can be
3545 enabled by configuring with:
3547 .../configure --enable-gdbmi
3549 *** Changes in GDB-4.18:
3551 * New native configurations
3553 HP-UX 10.20 hppa*-*-hpux10.20
3554 HP-UX 11.x hppa*-*-hpux11.0*
3555 M68K GNU/Linux m68*-*-linux*
3559 Fujitsu FR30 fr30-*-elf*
3560 Intel StrongARM strongarm-*-*
3561 Mitsubishi D30V d30v-*-*
3563 * OBSOLETE configurations
3565 Gould PowerNode, NP1 np1-*-*, pn-*-*
3567 Configurations that have been declared obsolete will be commented out,
3568 but the code will be left in place. If there is no activity to revive
3569 these configurations before the next release of GDB, the sources will
3570 be permanently REMOVED.
3574 As a compatibility experiment, GDB's source files buildsym.h and
3575 buildsym.c have been converted to pure standard C, no longer
3576 containing any K&R compatibility code. We believe that all systems in
3577 use today either come with a standard C compiler, or have a GCC port
3578 available. If this is not true, please report the affected
3579 configuration to bug-gdb@gnu.org immediately. See the README file for
3580 information about getting a standard C compiler if you don't have one
3585 GDB now uses readline 2.2.
3587 * set extension-language
3589 You can now control the mapping between filename extensions and source
3590 languages by using the `set extension-language' command. For instance,
3591 you can ask GDB to treat .c files as C++ by saying
3592 set extension-language .c c++
3593 The command `info extensions' lists all of the recognized extensions
3594 and their associated languages.
3596 * Setting processor type for PowerPC and RS/6000
3598 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3599 you can use the `set processor' command to specify what variant of the
3600 PowerPC family you are debugging. The command
3604 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3605 following PowerPC and RS6000 variants:
3607 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3608 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3610 403GC IBM PowerPC 403GC
3611 505 Motorola PowerPC 505
3612 860 Motorola PowerPC 860 or 850
3613 601 Motorola PowerPC 601
3614 602 Motorola PowerPC 602
3615 603 Motorola/IBM PowerPC 603 or 603e
3616 604 Motorola PowerPC 604 or 604e
3617 750 Motorola/IBM PowerPC 750 or 750
3619 At the moment, this command just tells GDB what to name the
3620 special-purpose processor registers. Since almost all the affected
3621 registers are inaccessible to user-level programs, this command is
3622 only useful for remote debugging in its present form.
3626 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3627 more extensive support for HP-UX. Added features include shared
3628 library support, kernel threads and hardware watchpoints for 11.00,
3629 support for HP's ANSI C and C++ compilers, and a compatibility mode
3630 for xdb and dbx commands.
3634 HP's donation includes the new concept of catchpoints, which is a
3635 generalization of the old catch command. On HP-UX, it is now possible
3636 to catch exec, fork, and vfork, as well as library loading.
3638 This means that the existing catch command has changed; its first
3639 argument now specifies the type of catch to be set up. See the
3640 output of "help catch" for a list of catchpoint types.
3642 * Debugging across forks
3644 On HP-UX, you can choose which process to debug when a fork() happens
3649 HP has donated a curses-based terminal user interface (TUI). To get
3650 it, build with --enable-tui. Although this can be enabled for any
3651 configuration, at present it only works for native HP debugging.
3653 * GDB remote protocol additions
3655 A new protocol packet 'X' that writes binary data is now available.
3656 Default behavior is to try 'X', then drop back to 'M' if the stub
3657 fails to respond. The settable variable `remotebinarydownload'
3658 allows explicit control over the use of 'X'.
3660 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3661 full 64-bit address. The command
3663 set remoteaddresssize 32
3665 can be used to revert to the old behaviour. For existing remote stubs
3666 the change should not be noticed, as the additional address information
3669 In order to assist in debugging stubs, you may use the maintenance
3670 command `packet' to send any text string to the stub. For instance,
3672 maint packet heythere
3674 sends the packet "$heythere#<checksum>". Note that it is very easy to
3675 disrupt a debugging session by sending the wrong packet at the wrong
3678 The compare-sections command allows you to compare section data on the
3679 target to what is in the executable file without uploading or
3680 downloading, by comparing CRC checksums.
3682 * Tracing can collect general expressions
3684 You may now collect general expressions at tracepoints. This requires
3685 further additions to the target-side stub; see tracepoint.c and
3686 doc/agentexpr.texi for further details.
3688 * mask-address variable for Mips
3690 For Mips targets, you may control the zeroing of the upper 32 bits of
3691 a 64-bit address by entering `set mask-address on'. This is mainly
3692 of interest to users of embedded R4xxx and R5xxx processors.
3694 * Higher serial baud rates
3696 GDB's serial code now allows you to specify baud rates 57600, 115200,
3697 230400, and 460800 baud. (Note that your host system may not be able
3698 to achieve all of these rates.)
3702 The i960 configuration now includes an initial implementation of a
3703 builtin simulator, contributed by Jim Wilson.
3706 *** Changes in GDB-4.17:
3708 * New native configurations
3710 Alpha GNU/Linux alpha*-*-linux*
3711 Unixware 2.x i[3456]86-unixware2*
3712 Irix 6.x mips*-sgi-irix6*
3713 PowerPC GNU/Linux powerpc-*-linux*
3714 PowerPC Solaris powerpcle-*-solaris*
3715 Sparc GNU/Linux sparc-*-linux*
3716 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3720 Argonaut Risc Chip (ARC) arc-*-*
3721 Hitachi H8/300S h8300*-*-*
3722 Matsushita MN10200 w/simulator mn10200-*-*
3723 Matsushita MN10300 w/simulator mn10300-*-*
3724 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3725 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3726 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3727 Mitsubishi D10V w/simulator d10v-*-*
3728 Mitsubishi M32R/D w/simulator m32r-*-elf*
3729 Tsqware Sparclet sparclet-*-*
3730 NEC V850 w/simulator v850-*-*
3732 * New debugging protocols
3734 ARM with RDI protocol arm*-*-*
3735 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3736 DDB and LSI variants of PMON protocol mips*-*-*
3737 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3738 PowerPC with SDS protocol powerpc{,le}-*-eabi
3739 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3743 All configurations can now understand and use the DWARF 2 debugging
3744 format. The choice is automatic, if the symbol file contains DWARF 2
3749 GDB now includes basic Java language support. This support is
3750 only useful with Java compilers that produce native machine code.
3752 * solib-absolute-prefix and solib-search-path
3754 For SunOS and SVR4 shared libraries, you may now set the prefix for
3755 loading absolute shared library symbol files, and the search path for
3756 locating non-absolute shared library symbol files.
3758 * Live range splitting
3760 GDB can now effectively debug code for which GCC has performed live
3761 range splitting as part of its optimization. See gdb/doc/LRS for
3762 more details on the expected format of the stabs information.
3766 GDB's support for the GNU Hurd, including thread debugging, has been
3767 updated to work with current versions of the Hurd.
3771 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3772 instruction set. ARM GDB automatically detects when Thumb
3773 instructions are in use, and adjusts disassembly and backtracing
3778 GDB's MIPS target configurations now handle the MIP16 16-bit
3783 GDB now includes support for overlays; if an executable has been
3784 linked such that multiple sections are based at the same address, GDB
3785 will decide which section to use for symbolic info. You can choose to
3786 control the decision manually, using overlay commands, or implement
3787 additional target-side support and use "overlay load-target" to bring
3788 in the overlay mapping. Do "help overlay" for more detail.
3792 The command "info symbol <address>" displays information about
3793 the symbol at the specified address.
3797 The standard remote protocol now includes an extension that allows
3798 asynchronous collection and display of trace data. This requires
3799 extensive support in the target-side debugging stub. Tracing mode
3800 includes a new interaction mode in GDB and new commands: see the
3801 file tracepoint.c for more details.
3805 Configurations for embedded MIPS now include a simulator contributed
3806 by Cygnus Solutions. The simulator supports the instruction sets
3807 of most MIPS variants.
3811 Sparc configurations may now include the ERC32 simulator contributed
3812 by the European Space Agency. The simulator is not built into
3813 Sparc targets by default; configure with --enable-sim to include it.
3817 For target configurations that may include multiple variants of a
3818 basic architecture (such as MIPS and SH), you may now set the
3819 architecture explicitly. "set arch" sets, "info arch" lists
3820 the possible architectures.
3822 *** Changes in GDB-4.16:
3824 * New native configurations
3826 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3827 M68K NetBSD m68k-*-netbsd*
3828 PowerPC AIX 4.x powerpc-*-aix*
3829 PowerPC MacOS powerpc-*-macos*
3830 PowerPC Windows NT powerpcle-*-cygwin32
3831 RS/6000 AIX 4.x rs6000-*-aix4*
3835 ARM with RDP protocol arm-*-*
3836 I960 with MON960 i960-*-coff
3837 MIPS VxWorks mips*-*-vxworks*
3838 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3839 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3841 Matra Sparclet sparclet-*-*
3845 The powerpc-eabi configuration now includes the PSIM simulator,
3846 contributed by Andrew Cagney, with assistance from Mike Meissner.
3847 PSIM is a very elaborate model of the PowerPC, including not only
3848 basic instruction set execution, but also details of execution unit
3849 performance and I/O hardware. See sim/ppc/README for more details.
3853 GDB now works with Solaris 2.5.
3855 * Windows 95/NT native
3857 GDB will now work as a native debugger on Windows 95 and Windows NT.
3858 To build it from source, you must use the "gnu-win32" environment,
3859 which uses a DLL to emulate enough of Unix to run the GNU tools.
3860 Further information, binaries, and sources are available at
3861 ftp.cygnus.com, under pub/gnu-win32.
3863 * dont-repeat command
3865 If a user-defined command includes the command `dont-repeat', then the
3866 command will not be repeated if the user just types return. This is
3867 useful if the command is time-consuming to run, so that accidental
3868 extra keystrokes don't run the same command many times.
3870 * Send break instead of ^C
3872 The standard remote protocol now includes an option to send a break
3873 rather than a ^C to the target in order to interrupt it. By default,
3874 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3876 * Remote protocol timeout
3878 The standard remote protocol includes a new variable `remotetimeout'
3879 that allows you to set the number of seconds before GDB gives up trying
3880 to read from the target. The default value is 2.
3882 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3884 By default GDB will automatically keep track of objects as they are
3885 loaded and unloaded by the dynamic linker. By using the command `set
3886 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3887 when shared library events occur, thus allowing you to set breakpoints
3888 in shared libraries which are explicitly loaded by the inferior.
3890 Note this feature does not work on hpux8. On hpux9 you must link
3891 /usr/lib/end.o into your program. This feature should work
3892 automatically on hpux10.
3894 * Irix 5.x hardware watchpoint support
3896 Irix 5 configurations now support the use of hardware watchpoints.
3898 * Mips protocol "SYN garbage limit"
3900 When debugging a Mips target using the `target mips' protocol, you
3901 may set the number of characters that GDB will ignore by setting
3902 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3903 every character. The default value is 1050.
3905 * Recording and replaying remote debug sessions
3907 If you set `remotelogfile' to the name of a file, gdb will write to it
3908 a recording of a remote debug session. This recording may then be
3909 replayed back to gdb using "gdbreplay". See gdbserver/README for
3910 details. This is useful when you have a problem with GDB while doing
3911 remote debugging; you can make a recording of the session and send it
3912 to someone else, who can then recreate the problem.
3914 * Speedups for remote debugging
3916 GDB includes speedups for downloading and stepping MIPS systems using
3917 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3918 and more efficient S-record downloading.
3920 * Memory use reductions and statistics collection
3922 GDB now uses less memory and reports statistics about memory usage.
3923 Try the `maint print statistics' command, for example.
3925 *** Changes in GDB-4.15:
3927 * Psymtabs for XCOFF
3929 The symbol reader for AIX GDB now uses partial symbol tables. This
3930 can greatly improve startup time, especially for large executables.
3932 * Remote targets use caching
3934 Remote targets now use a data cache to speed up communication with the
3935 remote side. The data cache could lead to incorrect results because
3936 it doesn't know about volatile variables, thus making it impossible to
3937 debug targets which use memory mapped I/O devices. `set remotecache
3938 off' turns the the data cache off.
3940 * Remote targets may have threads
3942 The standard remote protocol now includes support for multiple threads
3943 in the target system, using new protocol commands 'H' and 'T'. See
3944 gdb/remote.c for details.
3948 If GDB is configured with `--enable-netrom', then it will include
3949 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3950 acts as though it is a bank of ROM on the target board, but you can
3951 write into it over the network. GDB's support consists only of
3952 support for fast loading into the emulated ROM; to debug, you must use
3953 another protocol, such as standard remote protocol. The usual
3954 sequence is something like
3956 target nrom <netrom-hostname>
3958 target remote <netrom-hostname>:1235
3962 GDB now includes support for the Apple Macintosh, as a host only. It
3963 may be run as either an MPW tool or as a standalone application, and
3964 it can debug through the serial port. All the usual GDB commands are
3965 available, but to the target command, you must supply "serial" as the
3966 device type instead of "/dev/ttyXX". See mpw-README in the main
3967 directory for more information on how to build. The MPW configuration
3968 scripts */mpw-config.in support only a few targets, and only the
3969 mips-idt-ecoff target has been tested.
3973 GDB configuration now uses autoconf. This is not user-visible,
3974 but does simplify configuration and building.
3978 GDB now supports hpux10.
3980 *** Changes in GDB-4.14:
3982 * New native configurations
3984 x86 FreeBSD i[345]86-*-freebsd
3985 x86 NetBSD i[345]86-*-netbsd
3986 NS32k NetBSD ns32k-*-netbsd
3987 Sparc NetBSD sparc-*-netbsd
3991 A29K VxWorks a29k-*-vxworks
3992 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3993 CPU32 EST-300 emulator m68*-*-est*
3994 PowerPC ELF powerpc-*-elf
3997 * Alpha OSF/1 support for procfs
3999 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4000 possible to attach to running processes. As the mounting of the /proc
4001 filesystem is optional on the Alpha, GDB automatically determines
4002 the availability of /proc during startup. This can lead to problems
4003 if /proc is unmounted after GDB has been started.
4005 * Arguments to user-defined commands
4007 User commands may accept up to 10 arguments separated by whitespace.
4008 Arguments are accessed within the user command via $arg0..$arg9. A
4011 print $arg0 + $arg1 + $arg2
4013 To execute the command use:
4016 Defines the command "adder" which prints the sum of its three arguments.
4017 Note the arguments are text substitutions, so they may reference variables,
4018 use complex expressions, or even perform inferior function calls.
4020 * New `if' and `while' commands
4022 This makes it possible to write more sophisticated user-defined
4023 commands. Both commands take a single argument, which is the
4024 expression to evaluate, and must be followed by the commands to
4025 execute, one per line, if the expression is nonzero, the list being
4026 terminated by the word `end'. The `if' command list may include an
4027 `else' word, which causes the following commands to be executed only
4028 if the expression is zero.
4030 * Fortran source language mode
4032 GDB now includes partial support for Fortran 77. It will recognize
4033 Fortran programs and can evaluate a subset of Fortran expressions, but
4034 variables and functions may not be handled correctly. GDB will work
4035 with G77, but does not yet know much about symbols emitted by other
4038 * Better HPUX support
4040 Most debugging facilities now work on dynamic executables for HPPAs
4041 running hpux9 or later. You can attach to running dynamically linked
4042 processes, but by default the dynamic libraries will be read-only, so
4043 for instance you won't be able to put breakpoints in them. To change
4044 that behavior do the following before running the program:
4050 This will cause the libraries to be mapped private and read-write.
4051 To revert to the normal behavior, do this:
4057 You cannot set breakpoints or examine data in the library until after
4058 the library is loaded if the function/data symbols do not have
4061 GDB can now also read debug symbols produced by the HP C compiler on
4062 HPPAs (sorry, no C++, Fortran or 68k support).
4064 * Target byte order now dynamically selectable
4066 You can choose which byte order to use with a target system, via the
4067 commands "set endian big" and "set endian little", and you can see the
4068 current setting by using "show endian". You can also give the command
4069 "set endian auto", in which case GDB will use the byte order
4070 associated with the executable. Currently, only embedded MIPS
4071 configurations support dynamic selection of target byte order.
4073 * New DOS host serial code
4075 This version uses DPMI interrupts to handle buffered I/O, so you
4076 no longer need to run asynctsr when debugging boards connected to
4079 *** Changes in GDB-4.13:
4081 * New "complete" command
4083 This lists all the possible completions for the rest of the line, if it
4084 were to be given as a command itself. This is intended for use by emacs.
4086 * Trailing space optional in prompt
4088 "set prompt" no longer adds a space for you after the prompt you set. This
4089 allows you to set a prompt which ends in a space or one that does not.
4091 * Breakpoint hit counts
4093 "info break" now displays a count of the number of times the breakpoint
4094 has been hit. This is especially useful in conjunction with "ignore"; you
4095 can ignore a large number of breakpoint hits, look at the breakpoint info
4096 to see how many times the breakpoint was hit, then run again, ignoring one
4097 less than that number, and this will get you quickly to the last hit of
4100 * Ability to stop printing at NULL character
4102 "set print null-stop" will cause GDB to stop printing the characters of
4103 an array when the first NULL is encountered. This is useful when large
4104 arrays actually contain only short strings.
4106 * Shared library breakpoints
4108 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4109 breakpoints in shared libraries before the executable is run.
4111 * Hardware watchpoints
4113 There is a new hardware breakpoint for the watch command for sparclite
4114 targets. See gdb/sparclite/hw_breakpoint.note.
4116 Hardware watchpoints are also now supported under GNU/Linux.
4120 Annotations have been added. These are for use with graphical interfaces,
4121 and are still experimental. Currently only gdba.el uses these.
4123 * Improved Irix 5 support
4125 GDB now works properly with Irix 5.2.
4127 * Improved HPPA support
4129 GDB now works properly with the latest GCC and GAS.
4131 * New native configurations
4133 Sequent PTX4 i[34]86-sequent-ptx4
4134 HPPA running OSF/1 hppa*-*-osf*
4135 Atari TT running SVR4 m68*-*-sysv4*
4136 RS/6000 LynxOS rs6000-*-lynxos*
4140 OS/9000 i[34]86-*-os9k
4141 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4144 * Hitachi SH7000 and E7000-PC ICE support
4146 There is now support for communicating with the Hitachi E7000-PC ICE.
4147 This is available automatically when GDB is configured for the SH.
4151 As usual, a variety of small fixes and improvements, both generic
4152 and configuration-specific. See the ChangeLog for more detail.
4154 *** Changes in GDB-4.12:
4156 * Irix 5 is now supported
4160 GDB-4.12 on the HPPA has a number of changes which make it unable
4161 to debug the output from the currently released versions of GCC and
4162 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4163 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4164 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4167 *** Changes in GDB-4.11:
4169 * User visible changes:
4173 The "set remotedebug" option is now consistent between the mips remote
4174 target, remote targets using the gdb-specific protocol, UDI (AMD's
4175 debug protocol for the 29k) and the 88k bug monitor. It is now an
4176 integer specifying a debug level (normally 0 or 1, but 2 means more
4177 debugging info for the mips target).
4179 * DEC Alpha native support
4181 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4182 debug info, but GDB works fairly well with the DEC compiler and should
4183 work with a future GCC release. See the README file for a few
4184 Alpha-specific notes.
4186 * Preliminary thread implementation
4188 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4190 * LynxOS native and target support for 386
4192 This release has been hosted on LynxOS 2.2, and also can be configured
4193 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4196 * Improvements in C++ mangling/demangling.
4198 This release has much better g++ debugging, specifically in name
4199 mangling/demangling, virtual function calls, print virtual table,
4200 call methods, ...etc.
4202 *** Changes in GDB-4.10:
4204 * User visible changes:
4206 Remote debugging using the GDB-specific (`target remote') protocol now
4207 supports the `load' command. This is only useful if you have some
4208 other way of getting the stub to the target system, and you can put it
4209 somewhere in memory where it won't get clobbered by the download.
4211 Filename completion now works.
4213 When run under emacs mode, the "info line" command now causes the
4214 arrow to point to the line specified. Also, "info line" prints
4215 addresses in symbolic form (as well as hex).
4217 All vxworks based targets now support a user settable option, called
4218 vxworks-timeout. This option represents the number of seconds gdb
4219 should wait for responses to rpc's. You might want to use this if
4220 your vxworks target is, perhaps, a slow software simulator or happens
4221 to be on the far side of a thin network line.
4225 This release contains support for using a DEC alpha as a GDB host for
4226 cross debugging. Native alpha debugging is not supported yet.
4229 *** Changes in GDB-4.9:
4233 This is the first GDB release which is accompanied by a matching testsuite.
4234 The testsuite requires installation of dejagnu, which should be available
4235 via ftp from most sites that carry GNU software.
4239 'Cfront' style demangling has had its name changed to 'ARM' style, to
4240 emphasize that it was written from the specifications in the C++ Annotated
4241 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4242 disclaimers, it still generated too much confusion with users attempting to
4243 use gdb with AT&T cfront.
4247 GDB now uses a standard remote interface to a simulator library.
4248 So far, the library contains simulators for the Zilog Z8001/2, the
4249 Hitachi H8/300, H8/500 and Super-H.
4251 * New targets supported
4253 H8/300 simulator h8300-hitachi-hms or h8300hms
4254 H8/500 simulator h8500-hitachi-hms or h8500hms
4255 SH simulator sh-hitachi-hms or sh
4256 Z8000 simulator z8k-zilog-none or z8ksim
4257 IDT MIPS board over serial line mips-idt-ecoff
4259 Cross-debugging to GO32 targets is supported. It requires a custom
4260 version of the i386-stub.c module which is integrated with the
4261 GO32 memory extender.
4263 * New remote protocols
4265 MIPS remote debugging protocol.
4267 * New source languages supported
4269 This version includes preliminary support for Chill, a Pascal like language
4270 used by telecommunications companies. Chill support is also being integrated
4271 into the GNU compiler, but we don't know when it will be publically available.
4274 *** Changes in GDB-4.8:
4276 * HP Precision Architecture supported
4278 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4279 version of this support was available as a set of patches from the
4280 University of Utah. GDB does not support debugging of programs
4281 compiled with the HP compiler, because HP will not document their file
4282 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4283 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4285 Many problems in the preliminary version have been fixed.
4287 * Faster and better demangling
4289 We have improved template demangling and fixed numerous bugs in the GNU style
4290 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4291 character types (wchar_t) are now supported. Demangling of each symbol is now
4292 only done once, and is cached when the symbol table for a file is read in.
4293 This results in a small increase in memory usage for C programs, a moderate
4294 increase in memory usage for C++ programs, and a fantastic speedup in
4297 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4298 from the specifications in the Annotated Reference Manual, which AT&T's
4299 compiler does not actually implement.
4301 * G++ multiple inheritance compiler problem
4303 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4304 inheritance lattices was reworked to properly discover ambiguities. We
4305 recently found an example which causes this new algorithm to fail in a
4306 very subtle way, producing bad debug information for those classes.
4307 The file 'gcc.patch' (in this directory) can be applied to gcc to
4308 circumvent the problem. A future GCC release will contain a complete
4311 The previous G++ debug info problem (mentioned below for the gdb-4.7
4312 release) is fixed in gcc version 2.3.2.
4314 * Improved configure script
4316 The `configure' script will now attempt to guess your system type if
4317 you don't supply a host system type. The old scheme of supplying a
4318 host system triplet is preferable over using this. All the magic is
4319 done in the new `config.guess' script. Examine it for details.
4321 We have also brought our configure script much more in line with the FSF's
4322 version. It now supports the --with-xxx options. In particular,
4323 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4324 The resulting GDB will not be able to read arbitrary object file formats --
4325 only the format ``expected'' to be used on the configured target system.
4326 We hope to make this the default in a future release.
4328 * Documentation improvements
4330 There's new internal documentation on how to modify GDB, and how to
4331 produce clean changes to the code. We implore people to read it
4332 before submitting changes.
4334 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4335 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4336 `info' files are also provided. To build `info' files from scratch,
4337 you will need the latest `makeinfo' release, which will be available in
4338 a future texinfo-X.Y release.
4340 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4341 We're not sure exactly which versions have this problem, but it has
4342 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4343 or better. If that isn't possible, there is a patch in
4344 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4345 around this problem.
4349 GDB now supports array constants that can be used in expressions typed in by
4350 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4351 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4354 The new directory `gdb/sparclite' contains a program that demonstrates
4355 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4357 * New native hosts supported
4359 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4360 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4362 * New targets supported
4364 AMD 29k family via UDI a29k-amd-udi or udi29k
4366 * New file formats supported
4368 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4369 HPUX core files, and SCO 3.2v2 core files.
4373 Attaching to processes now works again; thanks for the many bug reports.
4375 We have also stomped on a bunch of core dumps caused by
4376 printf_filtered("%s") problems.
4378 We eliminated a copyright problem on the rpc and ptrace header files
4379 for VxWorks, which was discovered at the last minute during the 4.7
4380 release. You should now be able to build a VxWorks GDB.
4382 You can now interrupt gdb while an attached process is running. This
4383 will cause the attached process to stop, and give control back to GDB.
4385 We fixed problems caused by using too many file descriptors
4386 for reading symbols from object files and libraries. This was
4387 especially a problem for programs that used many (~100) shared
4390 The `step' command now only enters a subroutine if there is line number
4391 information for the subroutine. Otherwise it acts like the `next'
4392 command. Previously, `step' would enter subroutines if there was
4393 any debugging information about the routine. This avoids problems
4394 when using `cc -g1' on MIPS machines.
4396 * Internal improvements
4398 GDB's internal interfaces have been improved to make it easier to support
4399 debugging of multiple languages in the future.
4401 GDB now uses a common structure for symbol information internally.
4402 Minimal symbols (derived from linkage symbols in object files), partial
4403 symbols (from a quick scan of debug information), and full symbols
4404 contain a common subset of information, making it easier to write
4405 shared code that handles any of them.
4407 * New command line options
4409 We now accept --silent as an alias for --quiet.
4413 The memory-mapped-malloc library is now licensed under the GNU Library
4414 General Public License.
4416 *** Changes in GDB-4.7:
4418 * Host/native/target split
4420 GDB has had some major internal surgery to untangle the support for
4421 hosts and remote targets. Now, when you configure GDB for a remote
4422 target, it will no longer load in all of the support for debugging
4423 local programs on the host. When fully completed and tested, this will
4424 ensure that arbitrary host/target combinations are possible.
4426 The primary conceptual shift is to separate the non-portable code in
4427 GDB into three categories. Host specific code is required any time GDB
4428 is compiled on that host, regardless of the target. Target specific
4429 code relates to the peculiarities of the target, but can be compiled on
4430 any host. Native specific code is everything else: it can only be
4431 built when the host and target are the same system. Child process
4432 handling and core file support are two common `native' examples.
4434 GDB's use of /proc for controlling Unix child processes is now cleaner.
4435 It has been split out into a single module under the `target_ops' vector,
4436 plus two native-dependent functions for each system that uses /proc.
4438 * New hosts supported
4440 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4441 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4442 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4444 * New targets supported
4446 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4447 68030 and CPU32 m68030-*-*, m68332-*-*
4449 * New native hosts supported
4451 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4452 (386bsd is not well tested yet)
4453 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4455 * New file formats supported
4457 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4458 supports reading of `a.out.adobe' object files, which are an a.out
4459 format extended with minimal information about multiple sections.
4463 `show copying' is the same as the old `info copying'.
4464 `show warranty' is the same as `info warrantee'.
4465 These were renamed for consistency. The old commands continue to work.
4467 `info handle' is a new alias for `info signals'.
4469 You can now define pre-command hooks, which attach arbitrary command
4470 scripts to any command. The commands in the hook will be executed
4471 prior to the user's command. You can also create a hook which will be
4472 executed whenever the program stops. See gdb.texinfo.
4476 We now deal with Cfront style name mangling, and can even extract type
4477 info from mangled symbols. GDB can automatically figure out which
4478 symbol mangling style your C++ compiler uses.
4480 Calling of methods and virtual functions has been improved as well.
4484 The crash that occured when debugging Sun Ansi-C compiled binaries is
4485 fixed. This was due to mishandling of the extra N_SO stabs output
4488 We also finally got Ultrix 4.2 running in house, and fixed core file
4489 support, with help from a dozen people on the net.
4491 John M. Farrell discovered that the reason that single-stepping was so
4492 slow on all of the Mips based platforms (primarily SGI and DEC) was
4493 that we were trying to demangle and lookup a symbol used for internal
4494 purposes on every instruction that was being stepped through. Changing
4495 the name of that symbol so that it couldn't be mistaken for a C++
4496 mangled symbol sped things up a great deal.
4498 Rich Pixley sped up symbol lookups in general by getting much smarter
4499 about when C++ symbol mangling is necessary. This should make symbol
4500 completion (TAB on the command line) much faster. It's not as fast as
4501 we'd like, but it's significantly faster than gdb-4.6.
4505 A new user controllable variable 'call_scratch_address' can
4506 specify the location of a scratch area to be used when GDB
4507 calls a function in the target. This is necessary because the
4508 usual method of putting the scratch area on the stack does not work
4509 in systems that have separate instruction and data spaces.
4511 We integrated changes to support the 29k UDI (Universal Debugger
4512 Interface), but discovered at the last minute that we didn't have all
4513 of the appropriate copyright paperwork. We are working with AMD to
4514 resolve this, and hope to have it available soon.
4518 We have sped up the remote serial line protocol, especially for targets
4519 with lots of registers. It now supports a new `expedited status' ('T')
4520 message which can be used in place of the existing 'S' status message.
4521 This allows the remote stub to send only the registers that GDB
4522 needs to make a quick decision about single-stepping or conditional
4523 breakpoints, eliminating the need to fetch the entire register set for
4524 each instruction being stepped through.
4526 The GDB remote serial protocol now implements a write-through cache for
4527 registers, only re-reading the registers if the target has run.
4529 There is also a new remote serial stub for SPARC processors. You can
4530 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4531 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4532 processor with a serial port.
4536 Configure.in files have become much easier to read and modify. A new
4537 `table driven' format makes it more obvious what configurations are
4538 supported, and what files each one uses.
4542 There is a new opcodes library which will eventually contain all of the
4543 disassembly routines and opcode tables. At present, it only contains
4544 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4545 disassembler (binutils/objdump) to share these routines.
4547 The libiberty library is now copylefted under the GNU Library General
4548 Public License. This allows more liberal use, and was done so libg++
4549 can use it. This makes no difference to GDB, since the Library License
4550 grants all the rights from the General Public License.
4554 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4555 reference to the stabs symbol info used by the debugger. It is (as far
4556 as we know) the only published document on this fascinating topic. We
4557 encourage you to read it, compare it to the stabs information on your
4558 system, and send improvements on the document in general (to
4559 bug-gdb@prep.ai.mit.edu).
4561 And, of course, many bugs have been fixed.
4564 *** Changes in GDB-4.6:
4566 * Better support for C++ function names
4568 GDB now accepts as input the "demangled form" of C++ overloaded function
4569 names and member function names, and can do command completion on such names
4570 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4571 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4572 Make use of command completion, it is your friend.
4574 GDB also now accepts a variety of C++ mangled symbol formats. They are
4575 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4576 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4577 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4578 for the list of formats.
4580 * G++ symbol mangling problem
4582 Recent versions of gcc have a bug in how they emit debugging information for
4583 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4584 directory) can be applied to gcc to fix the problem. Alternatively, if you
4585 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4586 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4587 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4590 * New 'maintenance' command
4592 All of the commands related to hacking GDB internals have been moved out of
4593 the main command set, and now live behind the 'maintenance' command. This
4594 can also be abbreviated as 'mt'. The following changes were made:
4596 dump-me -> maintenance dump-me
4597 info all-breakpoints -> maintenance info breakpoints
4598 printmsyms -> maintenance print msyms
4599 printobjfiles -> maintenance print objfiles
4600 printpsyms -> maintenance print psymbols
4601 printsyms -> maintenance print symbols
4603 The following commands are new:
4605 maintenance demangle Call internal GDB demangler routine to
4606 demangle a C++ link name and prints the result.
4607 maintenance print type Print a type chain for a given symbol
4609 * Change to .gdbinit file processing
4611 We now read the $HOME/.gdbinit file before processing the argv arguments
4612 (e.g. reading symbol files or core files). This allows global parameters to
4613 be set, which will apply during the symbol reading. The ./.gdbinit is still
4614 read after argv processing.
4616 * New hosts supported
4618 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4620 GNU/Linux support i386-unknown-linux or linux
4622 We are also including code to support the HP/PA running BSD and HPUX. This
4623 is almost guaranteed not to work, as we didn't have time to test or build it
4624 for this release. We are including it so that the more adventurous (or
4625 masochistic) of you can play with it. We also had major problems with the
4626 fact that the compiler that we got from HP doesn't support the -g option.
4629 * New targets supported
4631 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4633 * More smarts about finding #include files
4635 GDB now remembers the compilation directory for all include files, and for
4636 all files from which C is generated (like yacc and lex sources). This
4637 greatly improves GDB's ability to find yacc/lex sources, and include files,
4638 especially if you are debugging your program from a directory different from
4639 the one that contains your sources.
4641 We also fixed a bug which caused difficulty with listing and setting
4642 breakpoints in include files which contain C code. (In the past, you had to
4643 try twice in order to list an include file that you hadn't looked at before.)
4645 * Interesting infernals change
4647 GDB now deals with arbitrary numbers of sections, where the symbols for each
4648 section must be relocated relative to that section's landing place in the
4649 target's address space. This work was needed to support ELF with embedded
4650 stabs used by Solaris-2.0.
4652 * Bug fixes (of course!)
4654 There have been loads of fixes for the following things:
4655 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4656 i960, stabs, DOS(GO32), procfs, etc...
4658 See the ChangeLog for details.
4660 *** Changes in GDB-4.5:
4662 * New machines supported (host and target)
4664 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4666 SGI Irix-4.x mips-sgi-irix4 or iris4
4668 * New malloc package
4670 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4671 Mmalloc is capable of handling mutiple heaps of memory. It is also
4672 capable of saving a heap to a file, and then mapping it back in later.
4673 This can be used to greatly speedup the startup of GDB by using a
4674 pre-parsed symbol table which lives in a mmalloc managed heap. For
4675 more details, please read mmalloc/mmalloc.texi.
4679 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4680 'help info proc' for details.
4682 * MIPS ecoff symbol table format
4684 The code that reads MIPS symbol table format is now supported on all hosts.
4685 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4688 * File name changes for MS-DOS
4690 Many files in the config directories have been renamed to make it easier to
4691 support GDB on MS-DOSe systems (which have very restrictive file name
4692 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4693 environment) is close to working but has some remaining problems. Note
4694 that debugging of DOS programs is not supported, due to limitations
4695 in the ``operating system'', but it can be used to host cross-debugging.
4697 * Cross byte order fixes
4699 Many fixes have been made to support cross debugging of Sparc and MIPS
4700 targets from hosts whose byte order differs.
4702 * New -mapped and -readnow options
4704 If memory-mapped files are available on your system through the 'mmap'
4705 system call, you can use the -mapped option on the `file' or
4706 `symbol-file' commands to cause GDB to write the symbols from your
4707 program into a reusable file. If the program you are debugging is
4708 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4709 Future GDB debugging sessions will notice the presence of this file,
4710 and will quickly map in symbol information from it, rather than reading
4711 the symbol table from the executable program. Using the '-mapped'
4712 option in a GDB `file' or `symbol-file' command has the same effect as
4713 starting GDB with the '-mapped' command-line option.
4715 You can cause GDB to read the entire symbol table immediately by using
4716 the '-readnow' option with any of the commands that load symbol table
4717 information (or on the GDB command line). This makes the command
4718 slower, but makes future operations faster.
4720 The -mapped and -readnow options are typically combined in order to
4721 build a `fred.syms' file that contains complete symbol information.
4722 A simple GDB invocation to do nothing but build a `.syms' file for future
4725 gdb -batch -nx -mapped -readnow programname
4727 The `.syms' file is specific to the host machine on which GDB is run.
4728 It holds an exact image of GDB's internal symbol table. It cannot be
4729 shared across multiple host platforms.
4731 * longjmp() handling
4733 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4734 siglongjmp() without losing control. This feature has not yet been ported to
4735 all systems. It currently works on many 386 platforms, all MIPS-based
4736 platforms (SGI, DECstation, etc), and Sun3/4.
4740 Preliminary work has been put in to support the new Solaris OS from Sun. At
4741 this time, it can control and debug processes, but it is not capable of
4746 As always, many many bug fixes. The major areas were with g++, and mipsread.
4747 People using the MIPS-based platforms should experience fewer mysterious
4748 crashes and trashed symbol tables.
4750 *** Changes in GDB-4.4:
4752 * New machines supported (host and target)
4754 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4756 BSD Reno on Vax vax-dec-bsd
4757 Ultrix on Vax vax-dec-ultrix
4759 * New machines supported (target)
4761 AMD 29000 embedded, using EBMON a29k-none-none
4765 GDB continues to improve its handling of C++. `References' work better.
4766 The demangler has also been improved, and now deals with symbols mangled as
4767 per the Annotated C++ Reference Guide.
4769 GDB also now handles `stabs' symbol information embedded in MIPS
4770 `ecoff' symbol tables. Since the ecoff format was not easily
4771 extensible to handle new languages such as C++, this appeared to be a
4772 good way to put C++ debugging info into MIPS binaries. This option
4773 will be supported in the GNU C compiler, version 2, when it is
4776 * New features for SVR4
4778 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4779 shared libraries. Debugging dynamically linked programs should present
4780 only minor differences from debugging statically linked programs.
4782 The `info proc' command will print out information about any process
4783 on an SVR4 system (including the one you are debugging). At the moment,
4784 it prints the address mappings of the process.
4786 If you bring up GDB on another SVR4 system, please send mail to
4787 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4789 * Better dynamic linking support in SunOS
4791 Reading symbols from shared libraries which contain debugging symbols
4792 now works properly. However, there remain issues such as automatic
4793 skipping of `transfer vector' code during function calls, which
4794 make it harder to debug code in a shared library, than to debug the
4795 same code linked statically.
4799 GDB is now using the latest `getopt' routines from the FSF. This
4800 version accepts the -- prefix for options with long names. GDB will
4801 continue to accept the old forms (-option and +option) as well.
4802 Various single letter abbreviations for options have been explicity
4803 added to the option table so that they won't get overshadowed in the
4804 future by other options that begin with the same letter.
4808 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4809 Many assorted bugs have been handled. Many more remain to be handled.
4810 See the various ChangeLog files (primarily in gdb and bfd) for details.
4813 *** Changes in GDB-4.3:
4815 * New machines supported (host and target)
4817 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4818 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4819 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4821 * Almost SCO Unix support
4823 We had hoped to support:
4824 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4825 (except for core file support), but we discovered very late in the release
4826 that it has problems with process groups that render gdb unusable. Sorry
4827 about that. I encourage people to fix it and post the fixes.
4829 * Preliminary ELF and DWARF support
4831 GDB can read ELF object files on System V Release 4, and can handle
4832 debugging records for C, in DWARF format, in ELF files. This support
4833 is preliminary. If you bring up GDB on another SVR4 system, please
4834 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4839 GDB now uses the latest `readline' library. One user-visible change
4840 is that two tabs will list possible command completions, which previously
4841 required typing M-? (meta-question mark, or ESC ?).
4845 The `stepi' bug that many of you noticed has been squashed.
4846 Many bugs in C++ have been handled. Many more remain to be handled.
4847 See the various ChangeLog files (primarily in gdb and bfd) for details.
4849 * State of the MIPS world (in case you wondered):
4851 GDB can understand the symbol tables emitted by the compilers
4852 supplied by most vendors of MIPS-based machines, including DEC. These
4853 symbol tables are in a format that essentially nobody else uses.
4855 Some versions of gcc come with an assembler post-processor called
4856 mips-tfile. This program is required if you want to do source-level
4857 debugging of gcc-compiled programs. I believe FSF does not ship
4858 mips-tfile with gcc version 1, but it will eventually come with gcc
4861 Debugging of g++ output remains a problem. g++ version 1.xx does not
4862 really support it at all. (If you're lucky, you should be able to get
4863 line numbers and stack traces to work, but no parameters or local
4864 variables.) With some work it should be possible to improve the
4867 When gcc version 2 is released, you will have somewhat better luck.
4868 However, even then you will get confusing results for inheritance and
4871 We will eventually provide full debugging of g++ output on
4872 DECstations. This will probably involve some kind of stabs-in-ecoff
4873 encapulation, but the details have not been worked out yet.
4876 *** Changes in GDB-4.2:
4878 * Improved configuration
4880 Only one copy of `configure' exists now, and it is not self-modifying.
4881 Porting BFD is simpler.
4885 The `step' and `next' commands now only stop at the first instruction
4886 of a source line. This prevents the multiple stops that used to occur
4887 in switch statements, for-loops, etc. `Step' continues to stop if a
4888 function that has debugging information is called within the line.
4892 Lots of small bugs fixed. More remain.
4894 * New host supported (not target)
4896 Intel 386 PC clone running Mach i386-none-mach
4899 *** Changes in GDB-4.1:
4901 * Multiple source language support
4903 GDB now has internal scaffolding to handle several source languages.
4904 It determines the type of each source file from its filename extension,
4905 and will switch expression parsing and number formatting to match the
4906 language of the function in the currently selected stack frame.
4907 You can also specifically set the language to be used, with
4908 `set language c' or `set language modula-2'.
4912 GDB now has preliminary support for the GNU Modula-2 compiler,
4913 currently under development at the State University of New York at
4914 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4915 continue through the fall of 1991 and into 1992.
4917 Other Modula-2 compilers are currently not supported, and attempting to
4918 debug programs compiled with them will likely result in an error as the
4919 symbol table is read. Feel free to work on it, though!
4921 There are hooks in GDB for strict type checking and range checking,
4922 in the `Modula-2 philosophy', but they do not currently work.
4926 GDB can now write to executable and core files (e.g. patch
4927 a variable's value). You must turn this switch on, specify
4928 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4929 by assigning a new value to a variable. Modifications take
4932 * Automatic SunOS shared library reading
4934 When you run your program, GDB automatically determines where its
4935 shared libraries (if any) have been loaded, and reads their symbols.
4936 The `share' command is no longer needed. This also works when
4937 examining core files.
4941 You can specify the number of lines that the `list' command shows.
4944 * New machines supported (host and target)
4946 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4947 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4948 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4950 * New hosts supported (not targets)
4952 IBM RT/PC: romp-ibm-aix or rtpc
4954 * New targets supported (not hosts)
4956 AMD 29000 embedded with COFF a29k-none-coff
4957 AMD 29000 embedded with a.out a29k-none-aout
4958 Ultracomputer remote kernel debug a29k-nyu-kern
4960 * New remote interfaces
4966 *** Changes in GDB-4.0:
4970 Wide output is wrapped at good places to make the output more readable.
4972 Gdb now supports cross-debugging from a host machine of one type to a
4973 target machine of another type. Communication with the target system
4974 is over serial lines. The ``target'' command handles connecting to the
4975 remote system; the ``load'' command will download a program into the
4976 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4977 also supports debugging of realtime processes running under VxWorks,
4978 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4979 stub on the target system.
4981 New CPUs supported include the AMD 29000 and Intel 960.
4983 GDB now reads object files and symbol tables via a ``binary file''
4984 library, which allows a single copy of GDB to debug programs of multiple
4985 object file types such as a.out and coff.
4987 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4988 refcard.dvi and refcard.ps are available to format it).
4991 * Control-Variable user interface simplified
4993 All variables that control the operation of the debugger can be set
4994 by the ``set'' command, and displayed by the ``show'' command.
4996 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4997 ``Show prompt'' produces the response:
4998 Gdb's prompt is new-gdb=>.
5000 What follows are the NEW set commands. The command ``help set'' will
5001 print a complete list of old and new set commands. ``help set FOO''
5002 will give a longer description of the variable FOO. ``show'' will show
5003 all of the variable descriptions and their current settings.
5005 confirm on/off: Enables warning questions for operations that are
5006 hard to recover from, e.g. rerunning the program while
5007 it is already running. Default is ON.
5009 editing on/off: Enables EMACS style command line editing
5010 of input. Previous lines can be recalled with
5011 control-P, the current line can be edited with control-B,
5012 you can search for commands with control-R, etc.
5015 history filename NAME: NAME is where the gdb command history
5016 will be stored. The default is .gdb_history,
5017 or the value of the environment variable
5020 history size N: The size, in commands, of the command history. The
5021 default is 256, or the value of the environment variable
5024 history save on/off: If this value is set to ON, the history file will
5025 be saved after exiting gdb. If set to OFF, the
5026 file will not be saved. The default is OFF.
5028 history expansion on/off: If this value is set to ON, then csh-like
5029 history expansion will be performed on
5030 command line input. The default is OFF.
5032 radix N: Sets the default radix for input and output. It can be set
5033 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5034 in the current radix, so "set radix 10" is always a no-op.
5036 height N: This integer value is the number of lines on a page. Default
5037 is 24, the current `stty rows'' setting, or the ``li#''
5038 setting from the termcap entry matching the environment
5041 width N: This integer value is the number of characters on a line.
5042 Default is 80, the current `stty cols'' setting, or the ``co#''
5043 setting from the termcap entry matching the environment
5046 Note: ``set screensize'' is obsolete. Use ``set height'' and
5047 ``set width'' instead.
5049 print address on/off: Print memory addresses in various command displays,
5050 such as stack traces and structure values. Gdb looks
5051 more ``symbolic'' if you turn this off; it looks more
5052 ``machine level'' with it on. Default is ON.
5054 print array on/off: Prettyprint arrays. New convenient format! Default
5057 print demangle on/off: Print C++ symbols in "source" form if on,
5060 print asm-demangle on/off: Same, for assembler level printouts
5063 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5066 * Support for Epoch Environment.
5068 The epoch environment is a version of Emacs v18 with windowing. One
5069 new command, ``inspect'', is identical to ``print'', except that if you
5070 are running in the epoch environment, the value is printed in its own
5074 * Support for Shared Libraries
5076 GDB can now debug programs and core files that use SunOS shared libraries.
5077 Symbols from a shared library cannot be referenced
5078 before the shared library has been linked with the program (this
5079 happens after you type ``run'' and before the function main() is entered).
5080 At any time after this linking (including when examining core files
5081 from dynamically linked programs), gdb reads the symbols from each
5082 shared library when you type the ``sharedlibrary'' command.
5083 It can be abbreviated ``share''.
5085 sharedlibrary REGEXP: Load shared object library symbols for files
5086 matching a unix regular expression. No argument
5087 indicates to load symbols for all shared libraries.
5089 info sharedlibrary: Status of loaded shared libraries.
5094 A watchpoint stops execution of a program whenever the value of an
5095 expression changes. Checking for this slows down execution
5096 tremendously whenever you are in the scope of the expression, but is
5097 quite useful for catching tough ``bit-spreader'' or pointer misuse
5098 problems. Some machines such as the 386 have hardware for doing this
5099 more quickly, and future versions of gdb will use this hardware.
5101 watch EXP: Set a watchpoint (breakpoint) for an expression.
5103 info watchpoints: Information about your watchpoints.
5105 delete N: Deletes watchpoint number N (same as breakpoints).
5106 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5107 enable N: Re-enables watchpoint number N (same as breakpoints).
5110 * C++ multiple inheritance
5112 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5115 * C++ exception handling
5117 Gdb now supports limited C++ exception handling. Besides the existing
5118 ability to breakpoint on an exception handler, gdb can breakpoint on
5119 the raising of an exception (before the stack is peeled back to the
5122 catch FOO: If there is a FOO exception handler in the dynamic scope,
5123 set a breakpoint to catch exceptions which may be raised there.
5124 Multiple exceptions (``catch foo bar baz'') may be caught.
5126 info catch: Lists all exceptions which may be caught in the
5127 current stack frame.
5130 * Minor command changes
5132 The command ``call func (arg, arg, ...)'' now acts like the print
5133 command, except it does not print or save a value if the function's result
5134 is void. This is similar to dbx usage.
5136 The ``up'' and ``down'' commands now always print the frame they end up
5137 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5138 frames without printing.
5140 * New directory command
5142 'dir' now adds directories to the FRONT of the source search path.
5143 The path starts off empty. Source files that contain debug information
5144 about the directory in which they were compiled can be found even
5145 with an empty path; Sun CC and GCC include this information. If GDB can't
5146 find your source file in the current directory, type "dir .".
5148 * Configuring GDB for compilation
5150 For normal use, type ``./configure host''. See README or gdb.texinfo
5153 GDB now handles cross debugging. If you are remotely debugging between
5154 two different machines, type ``./configure host -target=targ''.
5155 Host is the machine where GDB will run; targ is the machine
5156 where the program that you are debugging will run.