1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
6 * GDB now supports access to MIPS DSP registers on Linux targets.
8 * GDB now supports debugging microMIPS binaries.
10 * The "info os" command on GNU/Linux can now display information on
11 several new classes of objects managed by the operating system:
12 "info os procgroups" lists process groups
13 "info os files" lists file descriptors
14 "info os sockets" lists internet-domain sockets
15 "info os shm" lists shared-memory regions
16 "info os semaphores" lists semaphores
17 "info os msg" lists message queues
18 "info os modules" lists loaded kernel modules
20 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
21 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
22 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
23 options and inspect the probe arguments using the new $_probe_arg family
24 of convenience variables. You can obtain more information about SystemTap
25 in <http://sourceware.org/systemtap/>.
27 * GDB now supports reversible debugging on ARM, it allows you to
28 debug basic ARM and THUMB instructions, and provides
29 record/replay support.
31 * The option "symbol-reloading" has been deleted as it is no longer used.
35 ** GDB commands implemented in Python can now be put in command class
38 ** The "maint set python print-stack on|off" is now deleted.
40 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
41 apply "flag enum"-style pretty-printing to any enum.
43 ** gdb.lookup_symbol can now work when there is no current frame.
45 ** gdb.Symbol now has a 'line' attribute, holding the line number in
46 the source at which the symbol was defined.
48 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
49 method 'value'. The former indicates whether the symbol needs a
50 frame in order to compute its value, and the latter computes the
53 ** A new method 'referenced_value' on gdb.Value objects which can
54 dereference pointer as well as C++ reference values.
56 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
57 which return the global and static blocks (as gdb.Block objects),
58 of the underlying symbol table, respectively.
60 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
61 object associated with a PC value.
63 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
64 of the address range occupied by code for the current source line.
66 * Go language support.
67 GDB now supports debugging programs written in the Go programming
70 * GDBserver now supports stdio connections.
71 E.g. (gdb) target remote | ssh myhost gdbserver - hello
73 * The binary "gdbtui" can no longer be built or installed.
74 Use "gdb -tui" instead.
76 * GDB will now print "flag" enums specially. A flag enum is one where
77 all the enumerator values have no bits in common when pairwise
78 "and"ed. When printing a value whose type is a flag enum, GDB will
79 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
80 (gdb) print (enum E) 3
83 * The filename part of a linespec will now match trailing components
84 of a source file name. For example, "break gcc/expr.c:1000" will
85 now set a breakpoint in build/gcc/expr.c, but not
88 * The "info proc" and "generate-core-file" commands will now also
89 work on remote targets connected to GDBserver on Linux.
91 * The command "info catch" has been removed. It has been disabled
94 * The "catch exception" and "catch assert" commands now accept
95 a condition at the end of the command, much like the "break"
96 command does. For instance:
98 (gdb) catch exception Constraint_Error if Barrier = True
100 Previously, it was possible to add a condition to such catchpoints,
101 but it had to be done as a second step, after the catchpoint had been
102 created, using the "condition" command.
104 * The "info static-tracepoint-marker" command will now also work on
105 native Linux targets with in-process agent.
107 * GDB can now set breakpoints on inlined functions.
109 * The .gdb_index section has been updated to include symbols for
110 inlined functions. GDB will ignore older .gdb_index sections by
111 default, which could cause symbol files to be loaded more slowly
112 until their .gdb_index sections can be recreated. The new option
113 --use-deprecated-index-sections will cause GDB to use any older
114 .gdb_index sections it finds. This will restore performance, but
115 the ability to set breakpoints on inlined functions will be lost
116 in symbol files with older .gdb_index sections.
118 The .gdb_index section has also been updated to record more information
119 about each symbol. This speeds up the "info variables", "info functions"
120 and "info types" commands when used with programs having the .gdb_index
121 section, as well as speeding up debugging with shared libraries using
122 the .gdb_index section.
124 * Ada support for GDB/MI Variable Objects has been added.
126 * GDB can now support 'breakpoint always-inserted mode' in 'record'
131 ** New command -info-os is the MI equivalent of "info os".
133 ** Output logs ("set logging" and related) now include MI output.
137 ** "catch load" and "catch unload" can be used to stop when a shared
138 library is loaded or unloaded, respectively.
140 ** "enable count" can be used to auto-disable a breakpoint after
143 ** "info vtbl" can be used to show the virtual method tables for
144 C++ and Java objects.
146 ** "explore" and its sub commands "explore value" and "explore type"
147 can be used to reccursively explore values and types of
148 expressions. These commands are available only if GDB is
149 configured with '--with-python'.
151 ** "info auto-load" shows status of all kinds of auto-loaded files,
152 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
153 sequences of commands files, "info auto-load python-scripts"
154 shows status of auto-loading Python script files,
155 "info auto-load local-gdbinit" shows status of loading init file
156 (.gdbinit) from current directory and "info auto-load libthread-db" shows
157 status of inferior specific thread debugging shared library loading.
159 ** "info auto-load-scripts", "set auto-load-scripts on|off"
160 and "show auto-load-scripts" commands have been deprecated, use their
161 "info auto-load python-scripts", "set auto-load python-scripts on|off"
162 and "show auto-load python-scripts" counterparts instead.
164 ** "dprintf location,format,args..." creates a dynamic printf, which
165 is basically a breakpoint that does a printf and immediately
166 resumes your program's execution, so it is like a printf that you
167 can insert dynamically at runtime instead of at compiletime.
169 ** "set print symbol"
171 Controls whether GDB attempts to display the symbol, if any,
172 corresponding to addresses it prints. This defaults to "on", but
173 you can set it to "off" to restore GDB's previous behavior.
175 * Deprecated commands
177 ** For the Renesas Super-H architecture, the "regs" command has been
178 deprecated, and "info all-registers" should be used instead.
182 Renesas RL78 rl78-*-elf
183 HP OpenVMS ia64 ia64-hp-openvms*
185 * GDBserver supports evaluation of breakpoint conditions. When
186 support is advertised by GDBserver, GDB may be told to send the
187 breakpoint conditions in bytecode form to GDBserver. GDBserver
188 will only report the breakpoint trigger to GDB when its condition
194 show mips compression
195 Select the compressed ISA encoding used in functions that have no symbol
196 information available. The encoding can be set to either of:
199 and is updated automatically from ELF file flags if available.
201 set breakpoint condition-evaluation
202 show breakpoint condition-evaluation
203 Control whether breakpoint conditions are evaluated by GDB ("host") or by
204 GDBserver ("target"). Default option "auto" chooses the most efficient
206 This option can improve debugger efficiency depending on the speed of the
210 Disable auto-loading globally.
213 Show auto-loading setting of all kinds of auto-loaded files.
215 set auto-load gdb-scripts on|off
216 show auto-load gdb-scripts
217 Control auto-loading of GDB canned sequences of commands files.
219 set auto-load python-scripts on|off
220 show auto-load python-scripts
221 Control auto-loading of Python script files.
223 set auto-load local-gdbinit on|off
224 show auto-load local-gdbinit
225 Control loading of init file (.gdbinit) from current directory.
227 set auto-load libthread-db on|off
228 show auto-load libthread-db
229 Control auto-loading of inferior specific thread debugging shared library.
231 set auto-load scripts-directory <dir1>[:<dir2>...]
232 show auto-load scripts-directory
233 Set a list of directories from which to load auto-loaded scripts.
234 Automatically loaded Python scripts and GDB scripts are located in one
235 of the directories listed by this option.
236 The delimiter (':' above) may differ according to the host platform.
238 set auto-load safe-path <dir1>[:<dir2>...]
239 show auto-load safe-path
240 Set a list of directories from which it is safe to auto-load files.
241 The delimiter (':' above) may differ according to the host platform.
243 set debug auto-load on|off
245 Control display of debugging info for auto-loading the files above.
247 set dprintf-style gdb|call
249 Control the way in which a dynamic printf is performed; "gdb" requests
250 a GDB printf command, while "call" causes dprintf to call a function
253 set dprintf-function <expr>
254 show dprintf-function
255 set dprintf-channel <expr>
257 Set the function and optional first argument to the call when using
258 the "call" style of dynamic printf.
260 * New configure options
263 Configure default value for the 'set auto-load scripts-directory'
264 setting above. It defaults to '$debugdir:$datadir/auto-load',
265 $debugdir representing global debugging info directories (available
266 via 'show debug-file-directory') and $datadir representing GDB's data
267 directory (available via 'show data-directory').
269 --with-auto-load-safe-path
270 Configure default value for the 'set auto-load safe-path' setting
271 above. It defaults to the --with-auto-load-dir setting.
273 --without-auto-load-safe-path
274 Set 'set auto-load safe-path' to '/', effectively disabling this
279 z0/z1 conditional breakpoints extension
281 The z0/z1 breakpoint insertion packets have been extended to carry
282 a list of conditional expressions over to the remote stub depending on the
283 condition evaluation mode. The use of this extension can be controlled
284 via the "set remote conditional-breakpoints-packet" command.
288 Specify the signals which the remote stub may pass to the debugged
289 program without GDB involvement.
291 * New command line options
293 --init-command=FILE, -ix Like --command, -x but execute it
294 before loading inferior.
295 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
296 execute it before loading inferior.
298 *** Changes in GDB 7.4
300 * GDB now handles ambiguous linespecs more consistently; the existing
301 FILE:LINE support has been expanded to other types of linespecs. A
302 breakpoint will now be set on all matching locations in all
303 inferiors, and locations will be added or removed according to
306 * GDB now allows you to skip uninteresting functions and files when
307 stepping with the "skip function" and "skip file" commands.
309 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
310 and "show remote hardware-watchpoint-length-limit". These allows to
311 set or show the maximum length limit (in bytes) of a remote
312 target hardware watchpoint.
314 This allows e.g. to use "unlimited" hardware watchpoints with the
315 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
316 watchpoints are slower than real hardware watchpoints but are
317 significantly faster than gdb software watchpoints.
321 ** The register_pretty_printer function in module gdb.printing now takes
322 an optional `replace' argument. If True, the new printer replaces any
325 ** The "maint set python print-stack on|off" command has been
326 deprecated and will be deleted in GDB 7.5.
327 A new command: "set python print-stack none|full|message" has
328 replaced it. Additionally, the default for "print-stack" is
329 now "message", which just prints the error message without
332 ** A prompt substitution hook (prompt_hook) is now available to the
335 ** A new Python module, gdb.prompt has been added to the GDB Python
336 modules library. This module provides functionality for
337 escape sequences in prompts (used by set/show
338 extended-prompt). These escape sequences are replaced by their
341 ** Python commands and convenience-functions located in
342 'data-directory'/python/gdb/command and
343 'data-directory'/python/gdb/function are now automatically loaded
346 ** Blocks now provide four new attributes. global_block and
347 static_block will return the global and static blocks
348 respectively. is_static and is_global are boolean attributes
349 that indicate if the block is one of those two types.
351 ** Symbols now provide the "type" attribute, the type of the symbol.
353 ** The "gdb.breakpoint" function has been deprecated in favor of
356 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
357 of a function. This class is based on the "finish" command
358 available in the CLI.
360 ** Type objects for struct and union types now allow access to
361 the fields using standard Python dictionary (mapping) methods.
362 For example, "some_type['myfield']" now works, as does
365 ** A new event "gdb.new_objfile" has been added, triggered by loading a
368 ** A new function, "deep_items" has been added to the gdb.types
369 module in the GDB Python modules library. This function returns
370 an iterator over the fields of a struct or union type. Unlike
371 the standard Python "iteritems" method, it will recursively traverse
372 any anonymous fields.
376 ** "*stopped" events can report several new "reason"s, such as
379 ** Breakpoint changes are now notified using new async records, like
380 "=breakpoint-modified".
382 ** New command -ada-task-info.
384 * libthread-db-search-path now supports two special values: $sdir and $pdir.
385 $sdir specifies the default system locations of shared libraries.
386 $pdir specifies the directory where the libpthread used by the application
389 GDB no longer looks in $sdir and $pdir after it has searched the directories
390 mentioned in libthread-db-search-path. If you want to search those
391 directories, they must be specified in libthread-db-search-path.
392 The default value of libthread-db-search-path on GNU/Linux and Solaris
393 systems is now "$sdir:$pdir".
395 $pdir is not supported by gdbserver, it is currently ignored.
396 $sdir is supported by gdbserver.
398 * New configure option --with-iconv-bin.
399 When using the internationalization support like the one in the GNU C
400 library, GDB will invoke the "iconv" program to get a list of supported
401 character sets. If this program lives in a non-standard location, one can
402 use this option to specify where to find it.
404 * When natively debugging programs on PowerPC BookE processors running
405 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
406 watchpoints, which specify a mask in addition to an address to watch.
407 The mask specifies that some bits of an address (the bits which are
408 reset in the mask) should be ignored when matching the address accessed
409 by the inferior against the watchpoint address. See the "PowerPC Embedded"
410 section in the user manual for more details.
412 * The new option --once causes GDBserver to stop listening for connections once
413 the first connection is made. The listening port used by GDBserver will
414 become available after that.
416 * New commands "info macros" and "alias" have been added.
418 * New function parameters suffix @entry specifies value of function parameter
419 at the time the function got called. Entry values are available only since
425 "!" is now an alias of the "shell" command.
426 Note that no space is needed between "!" and SHELL COMMAND.
430 watch EXPRESSION mask MASK_VALUE
431 The watch command now supports the mask argument which allows creation
432 of masked watchpoints, if the current architecture supports this feature.
434 info auto-load-scripts [REGEXP]
435 This command was formerly named "maintenance print section-scripts".
436 It is now generally useful and is no longer a maintenance-only command.
438 info macro [-all] [--] MACRO
439 The info macro command has new options `-all' and `--'. The first for
440 printing all definitions of a macro. The second for explicitly specifying
441 the end of arguments and the beginning of the macro name in case the macro
442 name starts with a hyphen.
444 collect[/s] EXPRESSIONS
445 The tracepoint collect command now takes an optional modifier "/s"
446 that directs it to dereference pointer-to-character types and
447 collect the bytes of memory up to a zero byte. The behavior is
448 similar to what you see when you use the regular print command on a
449 string. An optional integer following the "/s" sets a bound on the
450 number of bytes that will be collected.
453 The trace start command now interprets any supplied arguments as a
454 note to be recorded with the trace run, with an effect similar to
455 setting the variable trace-notes.
458 The trace stop command now interprets any arguments as a note to be
459 mentioned along with the tstatus report that the trace was stopped
460 with a command. The effect is similar to setting the variable
463 * Tracepoints can now be enabled and disabled at any time after a trace
464 experiment has been started using the standard "enable" and "disable"
465 commands. It is now possible to start a trace experiment with no enabled
466 tracepoints; GDB will display a warning, but will allow the experiment to
467 begin, assuming that tracepoints will be enabled as needed while the trace
470 * Fast tracepoints on 32-bit x86-architectures can now be placed at
471 locations with 4-byte instructions, when they were previously
472 limited to locations with instructions of 5 bytes or longer.
476 set debug dwarf2-read
477 show debug dwarf2-read
478 Turns on or off display of debugging messages related to reading
479 DWARF debug info. The default is off.
481 set debug symtab-create
482 show debug symtab-create
483 Turns on or off display of debugging messages related to symbol table
484 creation. The default is off.
488 Set the GDB prompt, and allow escape sequences to be inserted to
489 display miscellaneous information (see 'help set extended-prompt'
490 for the list of sequences). This prompt (and any information
491 accessed through the escape sequences) is updated every time the
494 set print entry-values (both|compact|default|if-needed|no|only|preferred)
495 show print entry-values
496 Set printing of frame argument values at function entry. In some cases
497 GDB can determine the value of function argument which was passed by the
498 function caller, even if the value was modified inside the called function.
500 set debug entry-values
501 show debug entry-values
502 Control display of debugging info for determining frame argument values at
503 function entry and virtual tail call frames.
505 set basenames-may-differ
506 show basenames-may-differ
507 Set whether a source file may have multiple base names.
508 (A "base name" is the name of a file with the directory part removed.
509 Example: The base name of "/home/user/hello.c" is "hello.c".)
510 If set, GDB will canonicalize file names (e.g., expand symlinks)
511 before comparing them. Canonicalization is an expensive operation,
512 but it allows the same file be known by more than one base name.
513 If not set (the default), all source files are assumed to have just
514 one base name, and gdb will do file name comparisons more efficiently.
520 Set a user name and notes for the current and any future trace runs.
521 This is useful for long-running and/or disconnected traces, to
522 inform others (or yourself) as to who is running the trace, supply
523 contact information, or otherwise explain what is going on.
526 show trace-stop-notes
527 Set a note attached to the trace run, that is displayed when the
528 trace has been stopped by a tstop command. This is useful for
529 instance as an explanation, if you are stopping a trace run that was
530 started by someone else.
536 Dynamically enable a tracepoint in a started trace experiment.
540 Dynamically disable a tracepoint in a started trace experiment.
544 Set the user and notes of the trace run.
548 Query the current status of a tracepoint.
552 Query the minimum length of instruction at which a fast tracepoint may
555 * Dcache size (number of lines) and line-size are now runtime-configurable
556 via "set dcache line" and "set dcache line-size" commands.
560 Texas Instruments TMS320C6x tic6x-*-*
564 Renesas RL78 rl78-*-elf
566 *** Changes in GDB 7.3.1
568 * The build failure for NetBSD and OpenBSD targets have now been fixed.
570 *** Changes in GDB 7.3
572 * GDB has a new command: "thread find [REGEXP]".
573 It finds the thread id whose name, target id, or thread extra info
574 matches the given regular expression.
576 * The "catch syscall" command now works on mips*-linux* targets.
578 * The -data-disassemble MI command now supports modes 2 and 3 for
579 dumping the instruction opcodes.
581 * New command line options
583 -data-directory DIR Specify DIR as the "data-directory".
584 This is mostly for testing purposes.
586 * The "maint set python auto-load on|off" command has been renamed to
587 "set auto-load-scripts on|off".
589 * GDB has a new command: "set directories".
590 It is like the "dir" command except that it replaces the
591 source path list instead of augmenting it.
593 * GDB now understands thread names.
595 On GNU/Linux, "info threads" will display the thread name as set by
596 prctl or pthread_setname_np.
598 There is also a new command, "thread name", which can be used to
599 assign a name internally for GDB to display.
602 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
603 has been integrated into GDB.
607 ** The function gdb.Write now accepts an optional keyword 'stream'.
608 This keyword, when provided, will direct the output to either
609 stdout, stderr, or GDB's logging output.
611 ** Parameters can now be be sub-classed in Python, and in particular
612 you may implement the get_set_doc and get_show_doc functions.
613 This improves how Parameter set/show documentation is processed
614 and allows for more dynamic content.
616 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
617 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
618 have an is_valid method.
620 ** Breakpoints can now be sub-classed in Python, and in particular
621 you may implement a 'stop' function that is executed each time
622 the inferior reaches that breakpoint.
624 ** New function gdb.lookup_global_symbol looks up a global symbol.
626 ** GDB values in Python are now callable if the value represents a
627 function. For example, if 'some_value' represents a function that
628 takes two integer parameters and returns a value, you can call
629 that function like so:
631 result = some_value (10,20)
633 ** Module gdb.types has been added.
634 It contains a collection of utilities for working with gdb.Types objects:
635 get_basic_type, has_field, make_enum_dict.
637 ** Module gdb.printing has been added.
638 It contains utilities for writing and registering pretty-printers.
639 New classes: PrettyPrinter, SubPrettyPrinter,
640 RegexpCollectionPrettyPrinter.
641 New function: register_pretty_printer.
643 ** New commands "info pretty-printers", "enable pretty-printer" and
644 "disable pretty-printer" have been added.
646 ** gdb.parameter("directories") is now available.
648 ** New function gdb.newest_frame returns the newest frame in the
651 ** The gdb.InferiorThread class has a new "name" attribute. This
652 holds the thread's name.
654 ** Python Support for Inferior events.
655 Python scripts can add observers to be notified of events
656 occurring in the process being debugged.
657 The following events are currently supported:
658 - gdb.events.cont Continue event.
659 - gdb.events.exited Inferior exited event.
660 - gdb.events.stop Signal received, and Breakpoint hit events.
664 ** GDB now puts template parameters in scope when debugging in an
665 instantiation. For example, if you have:
667 template<int X> int func (void) { return X; }
669 then if you step into func<5>, "print X" will show "5". This
670 feature requires proper debuginfo support from the compiler; it
671 was added to GCC 4.5.
673 ** The motion commands "next", "finish", "until", and "advance" now
674 work better when exceptions are thrown. In particular, GDB will
675 no longer lose control of the inferior; instead, the GDB will
676 stop the inferior at the point at which the exception is caught.
677 This functionality requires a change in the exception handling
678 code that was introduced in GCC 4.5.
680 * GDB now follows GCC's rules on accessing volatile objects when
681 reading or writing target state during expression evaluation.
682 One notable difference to prior behavior is that "print x = 0"
683 no longer generates a read of x; the value of the assignment is
684 now always taken directly from the value being assigned.
686 * GDB now has some support for using labels in the program's source in
687 linespecs. For instance, you can use "advance label" to continue
688 execution to a label.
690 * GDB now has support for reading and writing a new .gdb_index
691 section. This section holds a fast index of DWARF debugging
692 information and can be used to greatly speed up GDB startup and
693 operation. See the documentation for `save gdb-index' for details.
695 * The "watch" command now accepts an optional "-location" argument.
696 When used, this causes GDB to watch the memory referred to by the
697 expression. Such a watchpoint is never deleted due to it going out
700 * GDB now supports thread debugging of core dumps on GNU/Linux.
702 GDB now activates thread debugging using the libthread_db library
703 when debugging GNU/Linux core dumps, similarly to when debugging
704 live processes. As a result, when debugging a core dump file, GDB
705 is now able to display pthread_t ids of threads. For example, "info
706 threads" shows the same output as when debugging the process when it
707 was live. In earlier releases, you'd see something like this:
710 * 1 LWP 6780 main () at main.c:10
712 While now you see this:
715 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
717 It is also now possible to inspect TLS variables when debugging core
720 When debugging a core dump generated on a machine other than the one
721 used to run GDB, you may need to point GDB at the correct
722 libthread_db library with the "set libthread-db-search-path"
723 command. See the user manual for more details on this command.
725 * When natively debugging programs on PowerPC BookE processors running
726 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
727 which stop execution of the inferior whenever it executes an instruction
728 at any address within the specified range. See the "PowerPC Embedded"
729 section in the user manual for more details.
731 * New features in the GDB remote stub, GDBserver
733 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
734 and i686 LynxOS (version 5.x).
736 ** GDBserver is now supported on Blackfin Linux.
738 * New native configurations
740 ia64 HP-UX ia64-*-hpux*
744 Analog Devices, Inc. Blackfin Processor bfin-*
746 * Ada task switching is now supported on sparc-elf targets when
747 debugging a program using the Ravenscar Profile. For more information,
748 see the "Tasking Support when using the Ravenscar Profile" section
749 in the GDB user manual.
751 * Guile support was removed.
753 * New features in the GNU simulator
755 ** The --map-info flag lists all known core mappings.
757 ** CFI flashes may be simulated via the "cfi" device.
759 *** Changes in GDB 7.2
761 * Shared library support for remote targets by default
763 When GDB is configured for a generic, non-OS specific target, like
764 for example, --target=arm-eabi or one of the many *-*-elf targets,
765 GDB now queries remote stubs for loaded shared libraries using the
766 `qXfer:libraries:read' packet. Previously, shared library support
767 was always disabled for such configurations.
771 ** Argument Dependent Lookup (ADL)
773 In C++ ADL lookup directs function search to the namespaces of its
774 arguments even if the namespace has not been imported.
784 Here the compiler will search for `foo' in the namespace of 'b'
785 and find A::foo. GDB now supports this. This construct is commonly
786 used in the Standard Template Library for operators.
788 ** Improved User Defined Operator Support
790 In addition to member operators, GDB now supports lookup of operators
791 defined in a namespace and imported with a `using' directive, operators
792 defined in the global scope, operators imported implicitly from an
793 anonymous namespace, and the ADL operators mentioned in the previous
795 GDB now also supports proper overload resolution for all the previously
796 mentioned flavors of operators.
798 ** static const class members
800 Printing of static const class members that are initialized in the
801 class definition has been fixed.
803 * Windows Thread Information Block access.
805 On Windows targets, GDB now supports displaying the Windows Thread
806 Information Block (TIB) structure. This structure is visible either
807 by using the new command `info w32 thread-information-block' or, by
808 dereferencing the new convenience variable named `$_tlb', a
809 thread-specific pointer to the TIB. This feature is also supported
810 when remote debugging using GDBserver.
814 Static tracepoints are calls in the user program into a tracing
815 library. One such library is a port of the LTTng kernel tracer to
816 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
817 When debugging with GDBserver, GDB now supports combining the GDB
818 tracepoint machinery with such libraries. For example: the user can
819 use GDB to probe a static tracepoint marker (a call from the user
820 program into the tracing library) with the new "strace" command (see
821 "New commands" below). This creates a "static tracepoint" in the
822 breakpoint list, that can be manipulated with the same feature set
823 as fast and regular tracepoints. E.g., collect registers, local and
824 global variables, collect trace state variables, and define
825 tracepoint conditions. In addition, the user can collect extra
826 static tracepoint marker specific data, by collecting the new
827 $_sdata internal variable. When analyzing the trace buffer, you can
828 inspect $_sdata like any other variable available to GDB. For more
829 information, see the "Tracepoints" chapter in GDB user manual. New
830 remote packets have been defined to support static tracepoints, see
831 the "New remote packets" section below.
833 * Better reconstruction of tracepoints after disconnected tracing
835 GDB will attempt to download the original source form of tracepoint
836 definitions when starting a trace run, and then will upload these
837 upon reconnection to the target, resulting in a more accurate
838 reconstruction of the tracepoints that are in use on the target.
842 You can now exercise direct control over the ways that GDB can
843 affect your program. For instance, you can disallow the setting of
844 breakpoints, so that the program can run continuously (assuming
845 non-stop mode). In addition, the "observer" variable is available
846 to switch all of the different controls; in observer mode, GDB
847 cannot affect the target's behavior at all, which is useful for
848 tasks like diagnosing live systems in the field.
850 * The new convenience variable $_thread holds the number of the
857 Return the address of the Windows Thread Information Block of a given thread.
861 In response to several of the tracepoint packets, the target may now
862 also respond with a number of intermediate `qRelocInsn' request
863 packets before the final result packet, to have GDB handle
864 relocating an instruction to execute at a different address. This
865 is particularly useful for stubs that support fast tracepoints. GDB
866 reports support for this feature in the qSupported packet.
870 List static tracepoint markers in the target program.
874 List static tracepoint markers at a given address in the target
877 qXfer:statictrace:read
879 Read the static trace data collected (by a `collect $_sdata'
880 tracepoint action). The remote stub reports support for this packet
881 to gdb's qSupported query.
885 Send the current settings of GDB's permission flags.
889 Send part of the source (textual) form of a tracepoint definition,
890 which includes location, conditional, and action list.
892 * The source command now accepts a -s option to force searching for the
893 script in the source search path even if the script name specifies
896 * New features in the GDB remote stub, GDBserver
898 - GDBserver now support tracepoints (including fast tracepoints, and
899 static tracepoints). The feature is currently supported by the
900 i386-linux and amd64-linux builds. See the "Tracepoints support
901 in gdbserver" section in the manual for more information.
903 GDBserver JIT compiles the tracepoint's conditional agent
904 expression bytecode into native code whenever possible for low
905 overhead dynamic tracepoints conditionals. For such tracepoints,
906 an expression that examines program state is evaluated when the
907 tracepoint is reached, in order to determine whether to capture
908 trace data. If the condition is simple and false, processing the
909 tracepoint finishes very quickly and no data is gathered.
911 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
912 for static tracepoints support.
914 - GDBserver now supports x86_64 Windows 64-bit debugging.
916 * GDB now sends xmlRegisters= in qSupported packet to indicate that
917 it understands register description.
919 * The --batch flag now disables pagination and queries.
921 * X86 general purpose registers
923 GDB now supports reading/writing byte, word and double-word x86
924 general purpose registers directly. This means you can use, say,
925 $ah or $ax to refer, respectively, to the byte register AH and
926 16-bit word register AX that are actually portions of the 32-bit
927 register EAX or 64-bit register RAX.
929 * The `commands' command now accepts a range of breakpoints to modify.
930 A plain `commands' following a command that creates multiple
931 breakpoints affects all the breakpoints set by that command. This
932 applies to breakpoints set by `rbreak', and also applies when a
933 single `break' command creates multiple breakpoints (e.g.,
934 breakpoints on overloaded c++ functions).
936 * The `rbreak' command now accepts a filename specification as part of
937 its argument, limiting the functions selected by the regex to those
938 in the specified file.
940 * Support for remote debugging Windows and SymbianOS shared libraries
941 from Unix hosts has been improved. Non Windows GDB builds now can
942 understand target reported file names that follow MS-DOS based file
943 system semantics, such as file names that include drive letters and
944 use the backslash character as directory separator. This makes it
945 possible to transparently use the "set sysroot" and "set
946 solib-search-path" on Unix hosts to point as host copies of the
947 target's shared libraries. See the new command "set
948 target-file-system-kind" described below, and the "Commands to
949 specify files" section in the user manual for more information.
953 eval template, expressions...
954 Convert the values of one or more expressions under the control
955 of the string template to a command line, and call it.
957 set target-file-system-kind unix|dos-based|auto
958 show target-file-system-kind
959 Set or show the assumed file system kind for target reported file
962 save breakpoints <filename>
963 Save all current breakpoint definitions to a file suitable for use
964 in a later debugging session. To read the saved breakpoint
965 definitions, use the `source' command.
967 `save tracepoints' is a new alias for `save-tracepoints'. The latter
970 info static-tracepoint-markers
971 Display information about static tracepoint markers in the target.
973 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
974 Define a static tracepoint by probing a marker at the given
975 function, line, address, or marker ID.
979 Enable and disable observer mode.
981 set may-write-registers on|off
982 set may-write-memory on|off
983 set may-insert-breakpoints on|off
984 set may-insert-tracepoints on|off
985 set may-insert-fast-tracepoints on|off
986 set may-interrupt on|off
987 Set individual permissions for GDB effects on the target. Note that
988 some of these settings can have undesirable or surprising
989 consequences, particularly when changed in the middle of a session.
990 For instance, disabling the writing of memory can prevent
991 breakpoints from being inserted, cause single-stepping to fail, or
992 even crash your program, if you disable after breakpoints have been
993 inserted. However, GDB should not crash.
995 set record memory-query on|off
996 show record memory-query
997 Control whether to stop the inferior if memory changes caused
998 by an instruction cannot be recorded.
1003 The disassemble command now supports "start,+length" form of two arguments.
1007 ** GDB now provides a new directory location, called the python directory,
1008 where Python scripts written for GDB can be installed. The location
1009 of that directory is <data-directory>/python, where <data-directory>
1010 is the GDB data directory. For more details, see section `Scripting
1011 GDB using Python' in the manual.
1013 ** The GDB Python API now has access to breakpoints, symbols, symbol
1014 tables, program spaces, inferiors, threads and frame's code blocks.
1015 Additionally, GDB Parameters can now be created from the API, and
1016 manipulated via set/show in the CLI.
1018 ** New functions gdb.target_charset, gdb.target_wide_charset,
1019 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1021 ** New exception gdb.GdbError.
1023 ** Pretty-printers are now also looked up in the current program space.
1025 ** Pretty-printers can now be individually enabled and disabled.
1027 ** GDB now looks for names of Python scripts to auto-load in a
1028 special section named `.debug_gdb_scripts', in addition to looking
1029 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1031 * Tracepoint actions were unified with breakpoint commands. In particular,
1032 there are no longer differences in "info break" output for breakpoints and
1033 tracepoints and the "commands" command can be used for both tracepoints and
1034 regular breakpoints.
1038 ARM Symbian arm*-*-symbianelf*
1040 * D language support.
1041 GDB now supports debugging programs written in the D programming
1044 * GDB now supports the extended ptrace interface for PowerPC which is
1045 available since Linux kernel version 2.6.34. This automatically enables
1046 any hardware breakpoints and additional hardware watchpoints available in
1047 the processor. The old ptrace interface exposes just one hardware
1048 watchpoint and no hardware breakpoints.
1050 * GDB is now able to use the Data Value Compare (DVC) register available on
1051 embedded PowerPC processors to implement in hardware simple watchpoint
1052 conditions of the form:
1054 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1056 This works in native GDB running on Linux kernels with the extended ptrace
1057 interface mentioned above.
1059 *** Changes in GDB 7.1
1063 ** Namespace Support
1065 GDB now supports importing of namespaces in C++. This enables the
1066 user to inspect variables from imported namespaces. Support for
1067 namepace aliasing has also been added. So, if a namespace is
1068 aliased in the current scope (e.g. namepace C=A; ) the user can
1069 print variables using the alias (e.g. (gdb) print C::x).
1073 All known bugs relating to the printing of virtual base class were
1074 fixed. It is now possible to call overloaded static methods using a
1079 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1080 and reinterpret_cast<> are now handled by the C++ expression parser.
1084 Xilinx MicroBlaze microblaze-*-*
1089 Xilinx MicroBlaze microblaze
1092 * Multi-program debugging.
1094 GDB now has support for multi-program (a.k.a. multi-executable or
1095 multi-exec) debugging. This allows for debugging multiple inferiors
1096 simultaneously each running a different program under the same GDB
1097 session. See "Debugging Multiple Inferiors and Programs" in the
1098 manual for more information. This implied some user visible changes
1099 in the multi-inferior support. For example, "info inferiors" now
1100 lists inferiors that are not running yet or that have exited
1101 already. See also "New commands" and "New options" below.
1103 * New tracing features
1105 GDB's tracepoint facility now includes several new features:
1107 ** Trace state variables
1109 GDB tracepoints now include support for trace state variables, which
1110 are variables managed by the target agent during a tracing
1111 experiment. They are useful for tracepoints that trigger each
1112 other, so for instance one tracepoint can count hits in a variable,
1113 and then a second tracepoint has a condition that is true when the
1114 count reaches a particular value. Trace state variables share the
1115 $-syntax of GDB convenience variables, and can appear in both
1116 tracepoint actions and condition expressions. Use the "tvariable"
1117 command to create, and "info tvariables" to view; see "Trace State
1118 Variables" in the manual for more detail.
1122 GDB now includes an option for defining fast tracepoints, which
1123 targets may implement more efficiently, such as by installing a jump
1124 into the target agent rather than a trap instruction. The resulting
1125 speedup can be by two orders of magnitude or more, although the
1126 tradeoff is that some program locations on some target architectures
1127 might not allow fast tracepoint installation, for instance if the
1128 instruction to be replaced is shorter than the jump. To request a
1129 fast tracepoint, use the "ftrace" command, with syntax identical to
1130 the regular trace command.
1132 ** Disconnected tracing
1134 It is now possible to detach GDB from the target while it is running
1135 a trace experiment, then reconnect later to see how the experiment
1136 is going. In addition, a new variable disconnected-tracing lets you
1137 tell the target agent whether to continue running a trace if the
1138 connection is lost unexpectedly.
1142 GDB now has the ability to save the trace buffer into a file, and
1143 then use that file as a target, similarly to you can do with
1144 corefiles. You can select trace frames, print data that was
1145 collected in them, and use tstatus to display the state of the
1146 tracing run at the moment that it was saved. To create a trace
1147 file, use "tsave <filename>", and to use it, do "target tfile
1150 ** Circular trace buffer
1152 You can ask the target agent to handle the trace buffer as a
1153 circular buffer, discarding the oldest trace frames to make room for
1154 newer ones, by setting circular-trace-buffer to on. This feature may
1155 not be available for all target agents.
1160 The disassemble command, when invoked with two arguments, now requires
1161 the arguments to be comma-separated.
1164 The info variables command now displays variable definitions. Files
1165 which only declare a variable are not shown.
1168 The source command is now capable of sourcing Python scripts.
1169 This feature is dependent on the debugger being build with Python
1172 Related to this enhancement is also the introduction of a new command
1173 "set script-extension" (see below).
1175 * New commands (for set/show, see "New options" below)
1177 record save [<FILENAME>]
1178 Save a file (in core file format) containing the process record
1179 execution log for replay debugging at a later time.
1181 record restore <FILENAME>
1182 Restore the process record execution log that was saved at an
1183 earlier time, for replay debugging.
1185 add-inferior [-copies <N>] [-exec <FILENAME>]
1188 clone-inferior [-copies <N>] [ID]
1189 Make a new inferior ready to execute the same program another
1190 inferior has loaded.
1195 maint info program-spaces
1196 List the program spaces loaded into GDB.
1198 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1199 show remote interrupt-sequence
1200 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1201 as the sequence to the remote target in order to interrupt the execution.
1202 Ctrl-C is a default. Some system prefers BREAK which is high level of
1203 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1204 Magic SysRq g. It is BREAK signal and character 'g'.
1206 set remote interrupt-on-connect [on | off]
1207 show remote interrupt-on-connect
1208 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1209 remote target when gdb connects to it. This is needed when you debug
1212 set remotebreak [on | off]
1214 Deprecated. Use "set/show remote interrupt-sequence" instead.
1216 tvariable $NAME [ = EXP ]
1217 Create or modify a trace state variable.
1220 List trace state variables and their values.
1222 delete tvariable $NAME ...
1223 Delete one or more trace state variables.
1226 Evaluate the given expressions without collecting anything into the
1227 trace buffer. (Valid in tracepoint actions only.)
1229 ftrace FN / FILE:LINE / *ADDR
1230 Define a fast tracepoint at the given function, line, or address.
1232 * New expression syntax
1234 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1235 GDB now parses 0b101010 identically with 42.
1239 set follow-exec-mode new|same
1240 show follow-exec-mode
1241 Control whether GDB reuses the same inferior across an exec call or
1242 creates a new one. This is useful to be able to restart the old
1243 executable after the inferior having done an exec call.
1245 set default-collect EXPR, ...
1246 show default-collect
1247 Define a list of expressions to be collected at each tracepoint.
1248 This is a useful way to ensure essential items are not overlooked,
1249 such as registers or a critical global variable.
1251 set disconnected-tracing
1252 show disconnected-tracing
1253 If set to 1, the target is instructed to continue tracing if it
1254 loses its connection to GDB. If 0, the target is to stop tracing
1257 set circular-trace-buffer
1258 show circular-trace-buffer
1259 If set to on, the target is instructed to use a circular trace buffer
1260 and discard the oldest trace frames instead of stopping the trace due
1261 to a full trace buffer. If set to off, the trace stops when the buffer
1262 fills up. Some targets may not support this.
1264 set script-extension off|soft|strict
1265 show script-extension
1266 If set to "off", the debugger does not perform any script language
1267 recognition, and all sourced files are assumed to be GDB scripts.
1268 If set to "soft" (the default), files are sourced according to
1269 filename extension, falling back to GDB scripts if the first
1271 If set to "strict", files are sourced according to filename extension.
1273 set ada trust-PAD-over-XVS on|off
1274 show ada trust-PAD-over-XVS
1275 If off, activate a workaround against a bug in the debugging information
1276 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1277 the GCC sources for more information about the GNAT encoding and
1278 PAD types in particular). It is always safe to set this option to
1279 off, but this introduces a slight performance penalty. The default
1282 * Python API Improvements
1284 ** GDB provides the new class gdb.LazyString. This is useful in
1285 some pretty-printing cases. The new method gdb.Value.lazy_string
1286 provides a simple way to create objects of this type.
1288 ** The fields returned by gdb.Type.fields now have an
1289 `is_base_class' attribute.
1291 ** The new method gdb.Type.range returns the range of an array type.
1293 ** The new method gdb.parse_and_eval can be used to parse and
1294 evaluate an expression.
1296 * New remote packets
1299 Define a trace state variable.
1302 Get the current value of a trace state variable.
1305 Set desired tracing behavior upon disconnection.
1308 Set the trace buffer to be linear or circular.
1311 Get data about the tracepoints currently in use.
1315 Process record now works correctly with hardware watchpoints.
1317 Multiple bug fixes have been made to the mips-irix port, making it
1318 much more reliable. In particular:
1319 - Debugging threaded applications is now possible again. Previously,
1320 GDB would hang while starting the program, or while waiting for
1321 the program to stop at a breakpoint.
1322 - Attaching to a running process no longer hangs.
1323 - An error occurring while loading a core file has been fixed.
1324 - Changing the value of the PC register now works again. This fixes
1325 problems observed when using the "jump" command, or when calling
1326 a function from GDB, or even when assigning a new value to $pc.
1327 - With the "finish" and "return" commands, the return value for functions
1328 returning a small array is now correctly printed.
1329 - It is now possible to break on shared library code which gets executed
1330 during a shared library init phase (code executed while executing
1331 their .init section). Previously, the breakpoint would have no effect.
1332 - GDB is now able to backtrace through the signal handler for
1333 non-threaded programs.
1335 PIE (Position Independent Executable) programs debugging is now supported.
1336 This includes debugging execution of PIC (Position Independent Code) shared
1337 libraries although for that, it should be possible to run such libraries as an
1340 *** Changes in GDB 7.0
1342 * GDB now has an interface for JIT compilation. Applications that
1343 dynamically generate code can create symbol files in memory and register
1344 them with GDB. For users, the feature should work transparently, and
1345 for JIT developers, the interface is documented in the GDB manual in the
1346 "JIT Compilation Interface" chapter.
1348 * Tracepoints may now be conditional. The syntax is as for
1349 breakpoints; either an "if" clause appended to the "trace" command,
1350 or the "condition" command is available. GDB sends the condition to
1351 the target for evaluation using the same bytecode format as is used
1352 for tracepoint actions.
1354 * The disassemble command now supports: an optional /r modifier, print the
1355 raw instructions in hex as well as in symbolic form, and an optional /m
1356 modifier to print mixed source+assembly.
1358 * Process record and replay
1360 In a architecture environment that supports ``process record and
1361 replay'', ``process record and replay'' target can record a log of
1362 the process execution, and replay it with both forward and reverse
1365 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1366 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1367 set execution-direction {forward|reverse}, for targets that support
1370 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1371 feature is available with a native GDB running on kernel version
1374 * GDB now has support for multi-byte and wide character sets on the
1375 target. Strings whose character type is wchar_t, char16_t, or
1376 char32_t are now correctly printed. GDB supports wide- and unicode-
1377 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1378 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1379 `printf'. This feature requires iconv to work properly; if your
1380 system does not have a working iconv, GDB can use GNU libiconv. See
1381 the installation instructions for more information.
1383 * GDB now supports automatic retrieval of shared library files from
1384 remote targets. To use this feature, specify a system root that begins
1385 with the `remote:' prefix, either via the `set sysroot' command or via
1386 the `--with-sysroot' configure-time option.
1388 * "info sharedlibrary" now takes an optional regex of libraries to show,
1389 and it now reports if a shared library has no debugging information.
1391 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1392 now complete on file names.
1394 * When completing in expressions, gdb will attempt to limit
1395 completions to allowable structure or union fields, where appropriate.
1396 For instance, consider:
1398 # struct example { int f1; double f2; };
1399 # struct example variable;
1402 If the user types TAB at the end of this command line, the available
1403 completions will be "f1" and "f2".
1405 * Inlined functions are now supported. They show up in backtraces, and
1406 the "step", "next", and "finish" commands handle them automatically.
1408 * GDB now supports the token-splicing (##) and stringification (#)
1409 operators when expanding macros. It also supports variable-arity
1412 * GDB now supports inspecting extra signal information, exported by
1413 the new $_siginfo convenience variable. The feature is currently
1414 implemented on linux ARM, i386 and amd64.
1416 * GDB can now display the VFP floating point registers and NEON vector
1417 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1418 can provide these registers (requires Linux 2.6.30 or later). Remote
1419 and simulator targets may also provide them.
1421 * New remote packets
1424 Search memory for a sequence of bytes.
1427 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1428 operation over reliable transport links. Use of this packet is
1429 controlled by the `set remote noack-packet' command.
1432 Kill the process with the specified process ID. Use this in preference
1433 to `k' when multiprocess protocol extensions are supported.
1436 Obtains additional operating system information
1440 Read or write additional signal information.
1442 * Removed remote protocol undocumented extension
1444 An undocumented extension to the remote protocol's `S' stop reply
1445 packet that permited the stub to pass a process id was removed.
1446 Remote servers should use the `T' stop reply packet instead.
1448 * GDB now supports multiple function calling conventions according to the
1449 DWARF-2 DW_AT_calling_convention function attribute.
1451 * The SH target utilizes the aforementioned change to distinguish between gcc
1452 and Renesas calling convention. It also adds the new CLI commands
1453 `set/show sh calling-convention'.
1455 * GDB can now read compressed debug sections, as produced by GNU gold
1456 with the --compress-debug-sections=zlib flag.
1458 * 64-bit core files are now supported on AIX.
1460 * Thread switching is now supported on Tru64.
1462 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1463 which will be allocated using malloc later in program execution.
1465 * The qXfer:libraries:read remote procotol packet now allows passing a
1466 list of section offsets.
1468 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1469 conditions handling signals delivered during attach or thread creation
1470 have also been fixed.
1472 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1473 From the user's standpoint, all unqualified instances of True and False
1474 are treated as the standard definitions, regardless of context.
1476 * GDB now parses C++ symbol and type names more flexibly. For
1479 template<typename T> class C { };
1482 GDB will now correctly handle all of:
1484 ptype C<char const *>
1485 ptype C<char const*>
1486 ptype C<const char *>
1487 ptype C<const char*>
1489 * New features in the GDB remote stub, gdbserver
1491 - The "--wrapper" command-line argument tells gdbserver to use a
1492 wrapper program to launch programs for debugging.
1494 - On PowerPC and S/390 targets, it is now possible to use a single
1495 gdbserver executable to debug both 32-bit and 64-bit programs.
1496 (This requires gdbserver itself to be built as a 64-bit executable.)
1498 - gdbserver uses the new noack protocol mode for TCP connections to
1499 reduce communications latency, if also supported and enabled in GDB.
1501 - Support for the sparc64-linux-gnu target is now included in
1504 - The amd64-linux build of gdbserver now supports debugging both
1505 32-bit and 64-bit programs.
1507 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1508 now support hardware watchpoints, and will use them automatically
1513 GDB now has support for scripting using Python. Whether this is
1514 available is determined at configure time.
1516 New GDB commands can now be written in Python.
1518 * Ada tasking support
1520 Ada tasks can now be inspected in GDB. The following commands have
1524 Print the list of Ada tasks.
1526 Print detailed information about task number N.
1528 Print the task number of the current task.
1530 Switch the context of debugging to task number N.
1532 * Support for user-defined prefixed commands. The "define" command can
1533 add new commands to existing prefixes, e.g. "target".
1535 * Multi-inferior, multi-process debugging.
1537 GDB now has generalized support for multi-inferior debugging. See
1538 "Debugging Multiple Inferiors" in the manual for more information.
1539 Although availability still depends on target support, the command
1540 set is more uniform now. The GNU/Linux specific multi-forks support
1541 has been migrated to this new framework. This implied some user
1542 visible changes; see "New commands" and also "Removed commands"
1545 * Target descriptions can now describe the target OS ABI. See the
1546 "Target Description Format" section in the user manual for more
1549 * Target descriptions can now describe "compatible" architectures
1550 to indicate that the target can execute applications for a different
1551 architecture in addition to those for the main target architecture.
1552 See the "Target Description Format" section in the user manual for
1555 * Multi-architecture debugging.
1557 GDB now includes general supports for debugging applications on
1558 hybrid systems that use more than one single processor architecture
1559 at the same time. Each such hybrid architecture still requires
1560 specific support to be added. The only hybrid architecture supported
1561 in this version of GDB is the Cell Broadband Engine.
1563 * GDB now supports integrated debugging of Cell/B.E. applications that
1564 use both the PPU and SPU architectures. To enable support for hybrid
1565 Cell/B.E. debugging, you need to configure GDB to support both the
1566 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1567 --enable-targets configure option.
1569 * Non-stop mode debugging.
1571 For some targets, GDB now supports an optional mode of operation in
1572 which you can examine stopped threads while other threads continue
1573 to execute freely. This is referred to as non-stop mode, with the
1574 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1575 section in the user manual for more information.
1577 To be able to support remote non-stop debugging, a remote stub needs
1578 to implement the non-stop mode remote protocol extensions, as
1579 described in the "Remote Non-Stop" section of the user manual. The
1580 GDB remote stub, gdbserver, has been adjusted to support these
1581 extensions on linux targets.
1583 * New commands (for set/show, see "New options" below)
1585 catch syscall [NAME(S) | NUMBER(S)]
1586 Catch system calls. Arguments, which should be names of system
1587 calls or their numbers, mean catch only those syscalls. Without
1588 arguments, every syscall will be caught. When the inferior issues
1589 any of the specified syscalls, GDB will stop and announce the system
1590 call, both when it is called and when its call returns. This
1591 feature is currently available with a native GDB running on the
1592 Linux Kernel, under the following architectures: x86, x86_64,
1593 PowerPC and PowerPC64.
1595 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1597 Search memory for a sequence of bytes.
1599 maint set python print-stack
1600 maint show python print-stack
1601 Show a stack trace when an error is encountered in a Python script.
1604 Invoke CODE by passing it to the Python interpreter.
1609 These allow macros to be defined, undefined, and listed
1613 Show operating system information about processes.
1616 List the inferiors currently under GDB's control.
1619 Switch focus to inferior number NUM.
1622 Detach from inferior number NUM.
1625 Kill inferior number NUM.
1629 set spu stop-on-load
1630 show spu stop-on-load
1631 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1633 set spu auto-flush-cache
1634 show spu auto-flush-cache
1635 Control whether to automatically flush the software-managed cache
1636 during Cell/B.E. debugging.
1638 set sh calling-convention
1639 show sh calling-convention
1640 Control the calling convention used when calling SH target functions.
1643 show debug timestamp
1644 Control display of timestamps with GDB debugging output.
1646 set disassemble-next-line
1647 show disassemble-next-line
1648 Control display of disassembled source lines or instructions when
1651 set remote noack-packet
1652 show remote noack-packet
1653 Set/show the use of remote protocol QStartNoAckMode packet. See above
1654 under "New remote packets."
1656 set remote query-attached-packet
1657 show remote query-attached-packet
1658 Control use of remote protocol `qAttached' (query-attached) packet.
1660 set remote read-siginfo-object
1661 show remote read-siginfo-object
1662 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1665 set remote write-siginfo-object
1666 show remote write-siginfo-object
1667 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1670 set remote reverse-continue
1671 show remote reverse-continue
1672 Control use of remote protocol 'bc' (reverse-continue) packet.
1674 set remote reverse-step
1675 show remote reverse-step
1676 Control use of remote protocol 'bs' (reverse-step) packet.
1678 set displaced-stepping
1679 show displaced-stepping
1680 Control displaced stepping mode. Displaced stepping is a way to
1681 single-step over breakpoints without removing them from the debuggee.
1682 Also known as "out-of-line single-stepping".
1685 show debug displaced
1686 Control display of debugging info for displaced stepping.
1688 maint set internal-error
1689 maint show internal-error
1690 Control what GDB does when an internal error is detected.
1692 maint set internal-warning
1693 maint show internal-warning
1694 Control what GDB does when an internal warning is detected.
1699 Use a wrapper program to launch programs for debugging.
1701 set multiple-symbols (all|ask|cancel)
1702 show multiple-symbols
1703 The value of this variable can be changed to adjust the debugger behavior
1704 when an expression or a breakpoint location contains an ambiguous symbol
1705 name (an overloaded function name, for instance).
1707 set breakpoint always-inserted
1708 show breakpoint always-inserted
1709 Keep breakpoints always inserted in the target, as opposed to inserting
1710 them when resuming the target, and removing them when the target stops.
1711 This option can improve debugger performance on slow remote targets.
1713 set arm fallback-mode (arm|thumb|auto)
1714 show arm fallback-mode
1715 set arm force-mode (arm|thumb|auto)
1717 These commands control how ARM GDB determines whether instructions
1718 are ARM or Thumb. The default for both settings is auto, which uses
1719 the current CPSR value for instructions without symbols; previous
1720 versions of GDB behaved as if "set arm fallback-mode arm".
1722 set disable-randomization
1723 show disable-randomization
1724 Standalone programs run with the virtual address space randomization enabled
1725 by default on some platforms. This option keeps the addresses stable across
1726 multiple debugging sessions.
1730 Control whether other threads are stopped or not when some thread hits
1735 Requests that asynchronous execution is enabled in the target, if available.
1736 In this case, it's possible to resume target in the background, and interact
1737 with GDB while the target is running. "show target-async" displays the
1738 current state of asynchronous execution of the target.
1740 set target-wide-charset
1741 show target-wide-charset
1742 The target-wide-charset is the name of the character set that GDB
1743 uses when printing characters whose type is wchar_t.
1745 set tcp auto-retry (on|off)
1747 set tcp connect-timeout
1748 show tcp connect-timeout
1749 These commands allow GDB to retry failed TCP connections to a remote stub
1750 with a specified timeout period; this is useful if the stub is launched
1751 in parallel with GDB but may not be ready to accept connections immediately.
1753 set libthread-db-search-path
1754 show libthread-db-search-path
1755 Control list of directories which GDB will search for appropriate
1758 set schedule-multiple (on|off)
1759 show schedule-multiple
1760 Allow GDB to resume all threads of all processes or only threads of
1761 the current process.
1765 Use more aggressive caching for accesses to the stack. This improves
1766 performance of remote debugging (particularly backtraces) without
1767 affecting correctness.
1769 set interactive-mode (on|off|auto)
1770 show interactive-mode
1771 Control whether GDB runs in interactive mode (on) or not (off).
1772 When in interactive mode, GDB waits for the user to answer all
1773 queries. Otherwise, GDB does not wait and assumes the default
1774 answer. When set to auto (the default), GDB determines which
1775 mode to use based on the stdin settings.
1780 For program forks, this is replaced by the new more generic `info
1781 inferiors' command. To list checkpoints, you can still use the
1782 `info checkpoints' command, which was an alias for the `info forks'
1786 Replaced by the new `inferior' command. To switch between
1787 checkpoints, you can still use the `restart' command, which was an
1788 alias for the `fork' command.
1791 This is removed, since some targets don't have a notion of
1792 processes. To switch between processes, you can still use the
1793 `inferior' command using GDB's own inferior number.
1796 For program forks, this is replaced by the new more generic `kill
1797 inferior' command. To delete a checkpoint, you can still use the
1798 `delete checkpoint' command, which was an alias for the `delete
1802 For program forks, this is replaced by the new more generic `detach
1803 inferior' command. To detach a checkpoint, you can still use the
1804 `detach checkpoint' command, which was an alias for the `detach
1807 * New native configurations
1809 x86/x86_64 Darwin i[34567]86-*-darwin*
1811 x86_64 MinGW x86_64-*-mingw*
1815 Lattice Mico32 lm32-*
1816 x86 DICOS i[34567]86-*-dicos*
1817 x86_64 DICOS x86_64-*-dicos*
1820 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1821 (mingw32ce) debugging.
1827 These commands were actually not implemented on any target.
1829 *** Changes in GDB 6.8
1831 * New native configurations
1833 NetBSD/hppa hppa*-*netbsd*
1834 Xtensa GNU/Linux xtensa*-*-linux*
1838 NetBSD/hppa hppa*-*-netbsd*
1839 Xtensa GNU/Lunux xtensa*-*-linux*
1841 * Change in command line behavior -- corefiles vs. process ids.
1843 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1844 attaching to process NUMBER fails, GDB no longer attempts to open a
1845 core file named NUMBER. Attaching to a program using the -c option
1846 is no longer supported. Instead, use the '-p' or '--pid' options.
1848 * GDB can now be built as a native debugger for debugging Windows x86
1849 (mingw32) Portable Executable (PE) programs.
1851 * Pending breakpoints no longer change their number when their address
1854 * GDB now supports breakpoints with multiple locations,
1855 including breakpoints on C++ constructors, inside C++ templates,
1856 and in inlined functions.
1858 * GDB's ability to debug optimized code has been improved. GDB more
1859 accurately identifies function bodies and lexical blocks that occupy
1860 more than one contiguous range of addresses.
1862 * Target descriptions can now describe registers for PowerPC.
1864 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1865 registers on PowerPC targets.
1867 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1868 targets even when the libthread_db library is not available.
1870 * The GDB remote stub, gdbserver, now supports the new file transfer
1871 commands (remote put, remote get, and remote delete).
1873 * The GDB remote stub, gdbserver, now supports run and attach in
1874 extended-remote mode.
1876 * hppa*64*-*-hpux11* target broken
1877 The debugger is unable to start a program and fails with the following
1878 error: "Error trying to get information about dynamic linker".
1879 The gdb-6.7 release is also affected.
1881 * GDB now supports the --enable-targets= configure option to allow
1882 building a single GDB executable that supports multiple remote
1883 target architectures.
1885 * GDB now supports debugging C and C++ programs which use the
1886 Decimal Floating Point extension. In addition, the PowerPC target
1887 now has a set of pseudo-registers to inspect decimal float values
1888 stored in two consecutive float registers.
1890 * The -break-insert MI command can optionally create pending
1893 * Improved support for debugging Ada
1894 Many improvements to the Ada language support have been made. These
1896 - Better support for Ada2005 interface types
1897 - Improved handling of arrays and slices in general
1898 - Better support for Taft-amendment types
1899 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1901 - Improved command completion in Ada
1904 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1909 set print frame-arguments (all|scalars|none)
1910 show print frame-arguments
1911 The value of this variable can be changed to control which argument
1912 values should be printed by the debugger when displaying a frame.
1917 Transfer files to and from a remote target, and delete remote files.
1924 Transfer files to and from a remote target, and delete remote files.
1926 * New remote packets
1933 Open, close, read, write, and delete files on the remote system.
1936 Attach to an existing process on the remote system, in extended-remote
1940 Run a new process on the remote system, in extended-remote mode.
1942 *** Changes in GDB 6.7
1944 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1945 bfd, libiberty and opcodes, as revealed by static analysis donated by
1946 Coverity, Inc. (http://scan.coverity.com).
1948 * When looking up multiply-defined global symbols, GDB will now prefer the
1949 symbol definition in the current shared library if it was built using the
1950 -Bsymbolic linker option.
1952 * When the Text User Interface (TUI) is not configured, GDB will now
1953 recognize the -tui command-line option and print a message that the TUI
1956 * The GDB remote stub, gdbserver, now has lower overhead for high
1957 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1959 * GDB for MIPS targets now autodetects whether a remote target provides
1960 32-bit or 64-bit register values.
1962 * Support for C++ member pointers has been improved.
1964 * GDB now understands XML target descriptions, which specify the
1965 target's overall architecture. GDB can read a description from
1966 a local file or over the remote serial protocol.
1968 * Vectors of single-byte data use a new integer type which is not
1969 automatically displayed as character or string data.
1971 * The /s format now works with the print command. It displays
1972 arrays of single-byte integers and pointers to single-byte integers
1975 * Target descriptions can now describe target-specific registers,
1976 for architectures which have implemented the support (currently
1977 only ARM, M68K, and MIPS).
1979 * GDB and the GDB remote stub, gdbserver, now support the XScale
1982 * The GDB remote stub, gdbserver, has been updated to support
1983 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1984 has been rewritten to use the standard GDB remote protocol.
1986 * GDB can now step into C++ functions which are called through thunks.
1988 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1990 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1991 layout. It also supports a TextSeg= and DataSeg= response when only
1992 segment base addresses (rather than offsets) are available.
1994 * The /i format now outputs any trailing branch delay slot instructions
1995 immediately following the last instruction within the count specified.
1997 * The GDB remote protocol "T" stop reply packet now supports a
1998 "library" response. Combined with the new "qXfer:libraries:read"
1999 packet, this response allows GDB to debug shared libraries on targets
2000 where the operating system manages the list of loaded libraries (e.g.
2001 Windows and SymbianOS).
2003 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2004 (DLLs) on Windows and Windows CE targets.
2006 * GDB now supports a faster verification that a .debug file matches its binary
2007 according to its build-id signature, if the signature is present.
2013 Enable or disable hardware flow control (RTS/CTS) on the serial port
2014 when debugging using remote targets.
2016 set mem inaccessible-by-default
2017 show mem inaccessible-by-default
2018 If the target supplies a memory map, for instance via the remote
2019 protocol's "qXfer:memory-map:read" packet, setting this variable
2020 prevents GDB from accessing memory outside the memory map. This
2021 is useful for targets with memory mapped registers or which react
2022 badly to accesses of unmapped address space.
2024 set breakpoint auto-hw
2025 show breakpoint auto-hw
2026 If the target supplies a memory map, for instance via the remote
2027 protocol's "qXfer:memory-map:read" packet, setting this variable
2028 lets GDB use hardware breakpoints automatically for memory regions
2029 where it can not use software breakpoints. This covers both the
2030 "break" command and internal breakpoints used for other commands
2031 including "next" and "finish".
2034 catch exception unhandled
2035 Stop the program execution when Ada exceptions are raised.
2038 Stop the program execution when an Ada assertion failed.
2042 Set an alternate system root for target files. This is a more
2043 general version of "set solib-absolute-prefix", which is now
2044 an alias to "set sysroot".
2047 Provide extended SPU facility status information. This set of
2048 commands is available only when debugging the Cell/B.E. SPU
2051 * New native configurations
2053 OpenBSD/sh sh*-*openbsd*
2056 unset tdesc filename
2058 Use the specified local file as an XML target description, and do
2059 not query the target for its built-in description.
2063 OpenBSD/sh sh*-*-openbsd*
2064 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2065 Toshiba Media Processor mep-elf
2067 * New remote packets
2070 Ignore the specified signals; pass them directly to the debugged program
2071 without stopping other threads or reporting them to GDB.
2073 qXfer:features:read:
2074 Read an XML target description from the target, which describes its
2079 Read or write contents of an spufs file on the target system. These
2080 packets are available only on the Cell/B.E. SPU architecture.
2082 qXfer:libraries:read:
2083 Report the loaded shared libraries. Combined with new "T" packet
2084 response, this packet allows GDB to debug shared libraries on
2085 targets where the operating system manages the list of loaded
2086 libraries (e.g. Windows and SymbianOS).
2090 Support for these obsolete configurations has been removed.
2098 i[34567]86-*-lynxos*
2099 i[34567]86-*-netware*
2100 i[34567]86-*-sco3.2v5*
2101 i[34567]86-*-sco3.2v4*
2103 i[34567]86-*-sysv4.2*
2106 i[34567]86-*-unixware2*
2107 i[34567]86-*-unixware*
2116 * Other removed features
2123 Various m68k-only ROM monitors.
2130 Various Renesas ROM monitors and debugging interfaces for SH and
2135 Support for a Macraigor serial interface to on-chip debugging.
2136 GDB does not directly support the newer parallel or USB
2141 A debug information format. The predecessor to DWARF 2 and
2142 DWARF 3, which are still supported.
2144 Support for the HP aCC compiler on HP-UX/PA-RISC
2146 SOM-encapsulated symbolic debugging information, automatic
2147 invocation of pxdb, and the aCC custom C++ ABI. This does not
2148 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2149 with aCC can still be debugged on an assembly level.
2151 MIPS ".pdr" sections
2153 A MIPS-specific format used to describe stack frame layout
2154 in debugging information.
2158 GDB could work with an older version of Guile to debug
2159 the interpreter and Scheme programs running in it.
2161 set mips stack-arg-size
2162 set mips saved-gpreg-size
2164 Use "set mips abi" to control parameter passing for MIPS.
2166 *** Changes in GDB 6.6
2171 Cell Broadband Engine SPU spu-elf
2173 * GDB can now be configured as a cross-debugger targeting native Windows
2174 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2175 running on a Windows system over TCP/IP to debug Windows programs.
2177 * The GDB remote stub, gdbserver, has been updated to support Windows and
2178 Cygwin debugging. Both single-threaded and multi-threaded programs are
2181 * The "set trust-readonly-sections" command works again. This command was
2182 broken in GDB 6.3, 6.4, and 6.5.
2184 * The "load" command now supports writing to flash memory, if the remote
2185 stub provides the required support.
2187 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2188 longer requires symbolic debug information (e.g. DWARF-2).
2193 unset substitute-path
2194 show substitute-path
2195 Manage a list of substitution rules that GDB uses to rewrite the name
2196 of the directories where the sources are located. This can be useful
2197 for instance when the sources were moved to a different location
2198 between compilation and debugging.
2202 Print each CLI command as it is executed. Each command is prefixed with
2203 a number of `+' symbols representing the nesting depth.
2204 The source command now has a `-v' option to enable the same feature.
2208 The ARM Demon monitor support (RDP protocol, "target rdp").
2210 Kernel Object Display, an embedded debugging feature which only worked with
2211 an obsolete version of Cisco IOS.
2213 The 'set download-write-size' and 'show download-write-size' commands.
2215 * New remote packets
2218 Tell a stub about GDB client features, and request remote target features.
2219 The first feature implemented is PacketSize, which allows the target to
2220 specify the size of packets it can handle - to minimize the number of
2221 packets required and improve performance when connected to a remote
2225 Fetch an OS auxilliary vector from the remote stub. This packet is a
2226 more efficient replacement for qPart:auxv:read.
2228 qXfer:memory-map:read:
2229 Fetch a memory map from the remote stub, including information about
2230 RAM, ROM, and flash memory devices.
2235 Erase and program a flash memory device.
2237 * Removed remote packets
2240 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2241 used it, and only gdbserver implemented it.
2243 *** Changes in GDB 6.5
2247 Renesas M32C/M16C m32c-elf
2249 Morpho Technologies ms1 ms1-elf
2253 init-if-undefined Initialize a convenience variable, but
2254 only if it doesn't already have a value.
2256 The following commands are presently only implemented for native GNU/Linux:
2258 checkpoint Save a snapshot of the program state.
2260 restart <n> Return the program state to a
2261 previously saved state.
2263 info checkpoints List currently saved checkpoints.
2265 delete-checkpoint <n> Delete a previously saved checkpoint.
2267 set|show detach-on-fork Tell gdb whether to detach from a newly
2268 forked process, or to keep debugging it.
2270 info forks List forks of the user program that
2271 are available to be debugged.
2273 fork <n> Switch to debugging one of several
2274 forks of the user program that are
2275 available to be debugged.
2277 delete-fork <n> Delete a fork from the list of forks
2278 that are available to be debugged (and
2279 kill the forked process).
2281 detach-fork <n> Delete a fork from the list of forks
2282 that are available to be debugged (and
2283 allow the process to continue).
2287 Morpho Technologies ms2 ms1-elf
2289 * Improved Windows host support
2291 GDB now builds as a cross debugger hosted on i686-mingw32, including
2292 native console support, and remote communications using either
2293 network sockets or serial ports.
2295 * Improved Modula-2 language support
2297 GDB can now print most types in the Modula-2 syntax. This includes:
2298 basic types, set types, record types, enumerated types, range types,
2299 pointer types and ARRAY types. Procedure var parameters are correctly
2300 printed and hexadecimal addresses and character constants are also
2301 written in the Modula-2 syntax. Best results can be obtained by using
2302 GNU Modula-2 together with the -gdwarf-2 command line option.
2306 The ARM rdi-share module.
2308 The Netware NLM debug server.
2310 *** Changes in GDB 6.4
2312 * New native configurations
2314 OpenBSD/arm arm*-*-openbsd*
2315 OpenBSD/mips64 mips64-*-openbsd*
2319 Morpho Technologies ms1 ms1-elf
2321 * New command line options
2323 --batch-silent As for --batch, but totally silent.
2324 --return-child-result The debugger will exist with the same value
2325 the child (debugged) program exited with.
2326 --eval-command COMMAND, -ex COMMAND
2327 Execute a single GDB CLI command. This may be
2328 specified multiple times and in conjunction
2329 with the --command (-x) option.
2331 * Deprecated commands removed
2333 The following commands, that were deprecated in 2000, have been
2337 set|show arm disassembly-flavor set|show arm disassembler
2338 othernames set arm disassembler
2339 set|show remotedebug set|show debug remote
2340 set|show archdebug set|show debug arch
2341 set|show eventdebug set|show debug event
2344 * New BSD user-level threads support
2346 It is now possible to debug programs using the user-level threads
2347 library on OpenBSD and FreeBSD. Currently supported (target)
2350 FreeBSD/amd64 x86_64-*-freebsd*
2351 FreeBSD/i386 i386-*-freebsd*
2352 OpenBSD/i386 i386-*-openbsd*
2354 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2355 are not yet supported.
2357 * New support for Matsushita MN10300 w/sim added
2358 (Work in progress). mn10300-elf.
2360 * REMOVED configurations and files
2362 VxWorks and the XDR protocol *-*-vxworks
2363 Motorola MCORE mcore-*-*
2364 National Semiconductor NS32000 ns32k-*-*
2366 * New "set print array-indexes" command
2368 After turning this setting "on", GDB prints the index of each element
2369 when displaying arrays. The default is "off" to preserve the previous
2372 * VAX floating point support
2374 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2376 * User-defined command support
2378 In addition to using $arg0..$arg9 for argument passing, it is now possible
2379 to use $argc to determine now many arguments have been passed. See the
2380 section on user-defined commands in the user manual for more information.
2382 *** Changes in GDB 6.3:
2384 * New command line option
2386 GDB now accepts -l followed by a number to set the timeout for remote
2389 * GDB works with GCC -feliminate-dwarf2-dups
2391 GDB now supports a more compact representation of DWARF-2 debug
2392 information using DW_FORM_ref_addr references. These are produced
2393 by GCC with the option -feliminate-dwarf2-dups and also by some
2394 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2395 to use -feliminate-dwarf2-dups.
2397 * Internationalization
2399 When supported by the host system, GDB will be built with
2400 internationalization (libintl). The task of marking up the sources is
2401 continued, we're looking forward to our first translation.
2405 Initial support for debugging programs compiled with the GNAT
2406 implementation of the Ada programming language has been integrated
2407 into GDB. In this release, support is limited to expression evaluation.
2409 * New native configurations
2411 GNU/Linux/m32r m32r-*-linux-gnu
2415 GDB's remote protocol now includes support for the 'p' packet. This
2416 packet is used to fetch individual registers from a remote inferior.
2418 * END-OF-LIFE registers[] compatibility module
2420 GDB's internal register infrastructure has been completely rewritten.
2421 The new infrastructure making possible the implementation of key new
2422 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2425 GDB 6.3 will be the last release to include the the registers[]
2426 compatibility module that allowed out-of-date configurations to
2427 continue to work. This change directly impacts the following
2437 powerpc bdm protocol
2439 Unless there is activity to revive these configurations, they will be
2440 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2442 * OBSOLETE configurations and files
2444 Configurations that have been declared obsolete in this release have
2445 been commented out. Unless there is activity to revive these
2446 configurations, the next release of GDB will have their sources
2447 permanently REMOVED.
2456 *** Changes in GDB 6.2.1:
2458 * MIPS `break main; run' gave an heuristic-fence-post warning
2460 When attempting to run even a simple program, a warning about
2461 heuristic-fence-post being hit would be reported. This problem has
2464 * MIPS IRIX 'long double' crashed GDB
2466 When examining a long double variable, GDB would get a segmentation
2467 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2468 IRIX long double values).
2472 A bug in the VAX stack code was causing problems with the "next"
2473 command. This problem has been fixed.
2475 *** Changes in GDB 6.2:
2477 * Fix for ``many threads''
2479 On GNU/Linux systems that use the NPTL threads library, a program
2480 rapidly creating and deleting threads would confuse GDB leading to the
2483 ptrace: No such process.
2484 thread_db_get_info: cannot get thread info: generic error
2486 This problem has been fixed.
2488 * "-async" and "-noasync" options removed.
2490 Support for the broken "-noasync" option has been removed (it caused
2493 * New ``start'' command.
2495 This command runs the program until the begining of the main procedure.
2497 * New BSD Kernel Data Access Library (libkvm) interface
2499 Using ``target kvm'' it is now possible to debug kernel core dumps and
2500 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2501 platforms. Currently supported (native-only) configurations are:
2503 FreeBSD/amd64 x86_64-*-freebsd*
2504 FreeBSD/i386 i?86-*-freebsd*
2505 NetBSD/i386 i?86-*-netbsd*
2506 NetBSD/m68k m68*-*-netbsd*
2507 NetBSD/sparc sparc-*-netbsd*
2508 OpenBSD/amd64 x86_64-*-openbsd*
2509 OpenBSD/i386 i?86-*-openbsd*
2510 OpenBSD/m68k m68*-openbsd*
2511 OpenBSD/sparc sparc-*-openbsd*
2513 * Signal trampoline code overhauled
2515 Many generic problems with GDB's signal handling code have been fixed.
2516 These include: backtraces through non-contiguous stacks; recognition
2517 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2518 call; backtrace through a signal trampoline; step into and out of
2519 signal handlers; and single-stepping in the signal trampoline.
2521 Please note that kernel bugs are a limiting factor here. These
2522 features have been shown to work on an s390 GNU/Linux system that
2523 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2525 * Cygwin support for DWARF 2 added.
2527 * New native configurations
2529 GNU/Linux/hppa hppa*-*-linux*
2530 OpenBSD/hppa hppa*-*-openbsd*
2531 OpenBSD/m68k m68*-*-openbsd*
2532 OpenBSD/m88k m88*-*-openbsd*
2533 OpenBSD/powerpc powerpc-*-openbsd*
2534 NetBSD/vax vax-*-netbsd*
2535 OpenBSD/vax vax-*-openbsd*
2537 * END-OF-LIFE frame compatibility module
2539 GDB's internal frame infrastructure has been completely rewritten.
2540 The new infrastructure making it possible to support key new features
2541 including DWARF 2 Call Frame Information. To aid in the task of
2542 migrating old configurations to this new infrastructure, a
2543 compatibility module, that allowed old configurations to continue to
2544 work, was also included.
2546 GDB 6.2 will be the last release to include this frame compatibility
2547 module. This change directly impacts the following configurations:
2557 Unless there is activity to revive these configurations, they will be
2558 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2560 * REMOVED configurations and files
2562 Sun 3, running SunOS 3 m68*-*-sunos3*
2563 Sun 3, running SunOS 4 m68*-*-sunos4*
2564 Sun 2, running SunOS 3 m68000-*-sunos3*
2565 Sun 2, running SunOS 4 m68000-*-sunos4*
2566 Motorola 680x0 running LynxOS m68*-*-lynxos*
2567 AT&T 3b1/Unix pc m68*-att-*
2568 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2569 decstation mips-dec-* mips-little-*
2570 riscos mips-*-riscos* mips-*-sysv*
2571 sonymips mips-sony-*
2572 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2574 *** Changes in GDB 6.1.1:
2576 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2578 The TUI (Text-mode User Interface) is now built as part of a default
2579 GDB configuration. It is enabled by either selecting the TUI with the
2580 command line option "-i=tui" or by running the separate "gdbtui"
2581 program. For more information on the TUI, see the manual "Debugging
2584 * Pending breakpoint support (also included in GDB 6.1)
2586 Support has been added to allow you to specify breakpoints in shared
2587 libraries that have not yet been loaded. If a breakpoint location
2588 cannot be found, and the "breakpoint pending" option is set to auto,
2589 GDB queries you if you wish to make the breakpoint pending on a future
2590 shared-library load. If and when GDB resolves the breakpoint symbol,
2591 the pending breakpoint is removed as one or more regular breakpoints
2594 Pending breakpoints are very useful for GCJ Java debugging.
2596 * Fixed ISO-C build problems
2598 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2599 non ISO-C code that stopped them being built using a more strict ISO-C
2600 compiler (e.g., IBM's C compiler).
2602 * Fixed build problem on IRIX 5
2604 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2605 wasn't able to compile compile on an IRIX 5 system.
2607 * Added execute permission to gdb/gdbserver/configure
2609 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2610 permission. This bug would cause configure to fail on a number of
2611 systems (Solaris, IRIX). Ref: server/519.
2613 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2615 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2616 has been updated to use constant array sizes.
2618 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2620 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2621 its generated DWARF Call Frame Info. This encoding was causing GDB to
2622 panic, that panic has been fixed. Ref: gdb/1628.
2624 * Fixed a problem when examining parameters in shared library code.
2626 When examining parameters in optimized shared library code generated
2627 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2628 not available''. GDB now correctly displays the variable's value.
2630 *** Changes in GDB 6.1:
2632 * Removed --with-mmalloc
2634 Support for the mmalloc memory manager has been removed, as it
2635 conflicted with the internal gdb byte cache.
2637 * Changes in AMD64 configurations
2639 The AMD64 target now includes the %cs and %ss registers. As a result
2640 the AMD64 remote protocol has changed; this affects the floating-point
2641 and SSE registers. If you rely on those registers for your debugging,
2642 you should upgrade gdbserver on the remote side.
2644 * Revised SPARC target
2646 The SPARC target has been completely revised, incorporating the
2647 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2648 support for LynxOS and SunOS 4 has been dropped. Calling functions
2649 from within GDB on operating systems with a non-executable stack
2650 (Solaris, OpenBSD) now works.
2654 GDB has a new C++ demangler which does a better job on the mangled
2655 names generated by current versions of g++. It also runs faster, so
2656 with this and other changes gdb should now start faster on large C++
2659 * DWARF 2 Location Expressions
2661 GDB support for location expressions has been extended to support function
2662 arguments and frame bases. Older versions of GDB could crash when they
2665 * C++ nested types and namespaces
2667 GDB's support for nested types and namespaces in C++ has been
2668 improved, especially if you use the DWARF 2 debugging format. (This
2669 is the default for recent versions of GCC on most platforms.)
2670 Specifically, if you have a class "Inner" defined within a class or
2671 namespace "Outer", then GDB realizes that the class's name is
2672 "Outer::Inner", not simply "Inner". This should greatly reduce the
2673 frequency of complaints about not finding RTTI symbols. In addition,
2674 if you are stopped at inside of a function defined within a namespace,
2675 GDB modifies its name lookup accordingly.
2677 * New native configurations
2679 NetBSD/amd64 x86_64-*-netbsd*
2680 OpenBSD/amd64 x86_64-*-openbsd*
2681 OpenBSD/alpha alpha*-*-openbsd*
2682 OpenBSD/sparc sparc-*-openbsd*
2683 OpenBSD/sparc64 sparc64-*-openbsd*
2685 * New debugging protocols
2687 M32R with SDI protocol m32r-*-elf*
2689 * "set prompt-escape-char" command deleted.
2691 The command "set prompt-escape-char" has been deleted. This command,
2692 and its very obscure effet on GDB's prompt, was never documented,
2693 tested, nor mentioned in the NEWS file.
2695 * OBSOLETE configurations and files
2697 Configurations that have been declared obsolete in this release have
2698 been commented out. Unless there is activity to revive these
2699 configurations, the next release of GDB will have their sources
2700 permanently REMOVED.
2702 Sun 3, running SunOS 3 m68*-*-sunos3*
2703 Sun 3, running SunOS 4 m68*-*-sunos4*
2704 Sun 2, running SunOS 3 m68000-*-sunos3*
2705 Sun 2, running SunOS 4 m68000-*-sunos4*
2706 Motorola 680x0 running LynxOS m68*-*-lynxos*
2707 AT&T 3b1/Unix pc m68*-att-*
2708 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2709 decstation mips-dec-* mips-little-*
2710 riscos mips-*-riscos* mips-*-sysv*
2711 sonymips mips-sony-*
2712 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2714 * REMOVED configurations and files
2716 SGI Irix-4.x mips-sgi-irix4 or iris4
2717 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2718 Z8000 simulator z8k-zilog-none or z8ksim
2719 Matsushita MN10200 w/simulator mn10200-*-*
2720 H8/500 simulator h8500-hitachi-hms or h8500hms
2721 HP/PA running BSD hppa*-*-bsd*
2722 HP/PA running OSF/1 hppa*-*-osf*
2723 HP/PA Pro target hppa*-*-pro*
2724 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2725 386BSD i[3456]86-*-bsd*
2726 Sequent family i[3456]86-sequent-sysv4*
2727 i[3456]86-sequent-sysv*
2728 i[3456]86-sequent-bsd*
2729 SPARC running LynxOS sparc-*-lynxos*
2730 SPARC running SunOS 4 sparc-*-sunos4*
2731 Tsqware Sparclet sparclet-*-*
2732 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2734 *** Changes in GDB 6.0:
2738 Support for debugging the Objective-C programming language has been
2739 integrated into GDB.
2741 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2743 DWARF 2's Call Frame Information makes available compiler generated
2744 information that more exactly describes the program's run-time stack.
2745 By using this information, GDB is able to provide more robust stack
2748 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2749 have been updated to use a new backtrace mechanism which includes
2750 DWARF 2 CFI support.
2754 GDB's remote protocol has been extended to include support for hosted
2755 file I/O (where the remote target uses GDB's file system). See GDB's
2756 remote protocol documentation for details.
2758 * All targets using the new architecture framework.
2760 All of GDB's targets have been updated to use the new internal
2761 architecture framework. The way is now open for future GDB releases
2762 to include cross-architecture native debugging support (i386 on amd64,
2765 * GNU/Linux's Thread Local Storage (TLS)
2767 GDB now includes support for for the GNU/Linux implementation of
2768 per-thread variables.
2770 * GNU/Linux's Native POSIX Thread Library (NPTL)
2772 GDB's thread code has been updated to work with either the new
2773 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2775 * Separate debug info.
2777 GDB, in conjunction with BINUTILS, now supports a mechanism for
2778 automatically loading debug information from a separate file. Instead
2779 of shipping full debug and non-debug versions of system libraries,
2780 system integrators can now instead ship just the stripped libraries
2781 and optional debug files.
2783 * DWARF 2 Location Expressions
2785 DWARF 2 Location Expressions allow the compiler to more completely
2786 describe the location of variables (even in optimized code) to the
2789 GDB now includes preliminary support for location expressions (support
2790 for DW_OP_piece is still missing).
2794 A number of long standing bugs that caused GDB to die while starting a
2795 Java application have been fixed. GDB's Java support is now
2796 considered "useable".
2798 * GNU/Linux support for fork, vfork, and exec.
2800 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2801 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2804 * GDB supports logging output to a file
2806 There are two new commands, "set logging" and "show logging", which can be
2807 used to capture GDB's output to a file.
2809 * The meaning of "detach" has changed for gdbserver
2811 The "detach" command will now resume the application, as documented. To
2812 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2815 * d10v, m68hc11 `regs' command deprecated
2817 The `info registers' command has been updated so that it displays the
2818 registers using a format identical to the old `regs' command.
2822 A new command, "maint set profile on/off", has been added. This command can
2823 be used to enable or disable profiling while running GDB, to profile a
2824 session or a set of commands. In addition there is a new configure switch,
2825 "--enable-profiling", which will cause GDB to be compiled with profiling
2826 data, for more informative profiling results.
2828 * Default MI syntax changed to "mi2".
2830 The default MI (machine interface) syntax, enabled by the command line
2831 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2832 "mi1", can be enabled by specifying the option "-i=mi1".
2834 Support for the original "mi0" syntax (included in GDB 5.0) has been
2837 Fix for gdb/192: removed extraneous space when displaying frame level.
2838 Fix for gdb/672: update changelist is now output in mi list format.
2839 Fix for gdb/702: a -var-assign that updates the value now shows up
2840 in a subsequent -var-update.
2842 * New native configurations.
2844 FreeBSD/amd64 x86_64-*-freebsd*
2846 * Multi-arched targets.
2848 HP/PA HPUX11 hppa*-*-hpux*
2849 Renesas M32R/D w/simulator m32r-*-elf*
2851 * OBSOLETE configurations and files
2853 Configurations that have been declared obsolete in this release have
2854 been commented out. Unless there is activity to revive these
2855 configurations, the next release of GDB will have their sources
2856 permanently REMOVED.
2858 Z8000 simulator z8k-zilog-none or z8ksim
2859 Matsushita MN10200 w/simulator mn10200-*-*
2860 H8/500 simulator h8500-hitachi-hms or h8500hms
2861 HP/PA running BSD hppa*-*-bsd*
2862 HP/PA running OSF/1 hppa*-*-osf*
2863 HP/PA Pro target hppa*-*-pro*
2864 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2865 Sequent family i[3456]86-sequent-sysv4*
2866 i[3456]86-sequent-sysv*
2867 i[3456]86-sequent-bsd*
2868 Tsqware Sparclet sparclet-*-*
2869 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2871 * REMOVED configurations and files
2874 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2875 IBM AIX PS/2 i[3456]86-*-aix
2876 i386 running Mach 3.0 i[3456]86-*-mach3*
2877 i386 running Mach i[3456]86-*-mach*
2878 i386 running OSF/1 i[3456]86-*osf1mk*
2879 HP/Apollo 68k Family m68*-apollo*-sysv*,
2881 m68*-hp-bsd*, m68*-hp-hpux*
2882 Argonaut Risc Chip (ARC) arc-*-*
2883 Mitsubishi D30V d30v-*-*
2884 Fujitsu FR30 fr30-*-elf*
2885 OS/9000 i[34]86-*-os9k
2886 I960 with MON960 i960-*-coff
2888 * MIPS $fp behavior changed
2890 The convenience variable $fp, for the MIPS, now consistently returns
2891 the address of the current frame's base. Previously, depending on the
2892 context, $fp could refer to either $sp or the current frame's base
2893 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2894 The GNU Source-Level Debugger''.
2896 *** Changes in GDB 5.3:
2898 * GNU/Linux shared library multi-threaded performance improved.
2900 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2901 `/proc', in preference to `ptrace' for memory reads. This may result
2902 in an improvement in the start-up time of multi-threaded, shared
2903 library applications when run under GDB. One GDB user writes: ``loads
2904 shared libs like mad''.
2906 * ``gdbserver'' now supports multi-threaded applications on some targets
2908 Support for debugging multi-threaded applications which use
2909 the GNU/Linux LinuxThreads package has been added for
2910 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2911 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2913 * GDB now supports C/C++ preprocessor macros.
2915 GDB now expands preprocessor macro invocations in C/C++ expressions,
2916 and provides various commands for showing macro definitions and how
2919 The new command `macro expand EXPRESSION' expands any macro
2920 invocations in expression, and shows the result.
2922 The new command `show macro MACRO-NAME' shows the definition of the
2923 macro named MACRO-NAME, and where it was defined.
2925 Most compilers don't include information about macros in the debugging
2926 information by default. In GCC 3.1, for example, you need to compile
2927 your program with the options `-gdwarf-2 -g3'. If the macro
2928 information is present in the executable, GDB will read it.
2930 * Multi-arched targets.
2932 DEC Alpha (partial) alpha*-*-*
2933 DEC VAX (partial) vax-*-*
2935 National Semiconductor NS32000 (partial) ns32k-*-*
2936 Motorola 68000 (partial) m68k-*-*
2937 Motorola MCORE mcore-*-*
2941 Fujitsu FRV architecture added by Red Hat frv*-*-*
2944 * New native configurations
2946 Alpha NetBSD alpha*-*-netbsd*
2947 SH NetBSD sh*-*-netbsdelf*
2948 MIPS NetBSD mips*-*-netbsd*
2949 UltraSPARC NetBSD sparc64-*-netbsd*
2951 * OBSOLETE configurations and files
2953 Configurations that have been declared obsolete in this release have
2954 been commented out. Unless there is activity to revive these
2955 configurations, the next release of GDB will have their sources
2956 permanently REMOVED.
2958 Mitsubishi D30V d30v-*-*
2959 OS/9000 i[34]86-*-os9k
2960 IBM AIX PS/2 i[3456]86-*-aix
2961 Fujitsu FR30 fr30-*-elf*
2962 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2963 Argonaut Risc Chip (ARC) arc-*-*
2964 i386 running Mach 3.0 i[3456]86-*-mach3*
2965 i386 running Mach i[3456]86-*-mach*
2966 i386 running OSF/1 i[3456]86-*osf1mk*
2967 HP/Apollo 68k Family m68*-apollo*-sysv*,
2969 m68*-hp-bsd*, m68*-hp-hpux*
2970 I960 with MON960 i960-*-coff
2972 * OBSOLETE languages
2974 CHILL, a Pascal like language used by telecommunications companies.
2976 * REMOVED configurations and files
2978 AMD 29k family via UDI a29k-amd-udi, udi29k
2979 A29K VxWorks a29k-*-vxworks
2980 AMD 29000 embedded, using EBMON a29k-none-none
2981 AMD 29000 embedded with COFF a29k-none-coff
2982 AMD 29000 embedded with a.out a29k-none-aout
2984 testsuite/gdb.hp/gdb.threads-hp/ directory
2986 * New command "set max-user-call-depth <nnn>"
2988 This command allows the user to limit the call depth of user-defined
2989 commands. The default is 1024.
2991 * Changes in FreeBSD/i386 native debugging.
2993 Support for the "generate-core-file" has been added.
2995 * New commands "dump", "append", and "restore".
2997 These commands allow data to be copied from target memory
2998 to a bfd-format or binary file (dump and append), and back
2999 from a file into memory (restore).
3001 * Improved "next/step" support on multi-processor Alpha Tru64.
3003 The previous single-step mechanism could cause unpredictable problems,
3004 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3005 of a software single-step mechanism prevents this.
3007 *** Changes in GDB 5.2.1:
3015 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3016 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3017 Fix, by Joel Brobecker imported from mainline.
3019 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3020 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3021 Fix, by Fred Fish, imported from mainline.
3023 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3024 Surprisingly enough, it works now.
3025 By Michal Ludvig, imported from mainline.
3027 i386 hardware watchpoint support:
3028 avoid misses on second run for some targets.
3029 By Pierre Muller, imported from mainline.
3031 *** Changes in GDB 5.2:
3033 * New command "set trust-readonly-sections on[off]".
3035 This command is a hint that tells gdb that read-only sections
3036 really are read-only (ie. that their contents will not change).
3037 In this mode, gdb will go to the object file rather than the
3038 target to read memory from read-only sections (such as ".text").
3039 This can be a significant performance improvement on some
3040 (notably embedded) targets.
3042 * New command "generate-core-file" (or "gcore").
3044 This new gdb command allows the user to drop a core file of the child
3045 process state at any time. So far it's been implemented only for
3046 GNU/Linux and Solaris, but should be relatively easily ported to other
3047 hosts. Argument is core file name (defaults to core.<pid>).
3049 * New command line option
3051 GDB now accepts --pid or -p followed by a process id.
3053 * Change in command line behavior -- corefiles vs. process ids.
3055 There is a subtle behavior in the way in which GDB handles
3056 command line arguments. The first non-flag argument is always
3057 a program to debug, but the second non-flag argument may either
3058 be a corefile or a process id. Previously, GDB would attempt to
3059 open the second argument as a corefile, and if that failed, would
3060 issue a superfluous error message and then attempt to attach it as
3061 a process. Now, if the second argument begins with a non-digit,
3062 it will be treated as a corefile. If it begins with a digit,
3063 GDB will attempt to attach it as a process, and if no such process
3064 is found, will then attempt to open it as a corefile.
3066 * Changes in ARM configurations.
3068 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3069 configuration is fully multi-arch.
3071 * New native configurations
3073 ARM NetBSD arm*-*-netbsd*
3074 x86 OpenBSD i[3456]86-*-openbsd*
3075 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3076 Sparc64 running FreeBSD sparc64-*-freebsd*
3080 Sanyo XStormy16 xstormy16-elf
3082 * OBSOLETE configurations and files
3084 Configurations that have been declared obsolete in this release have
3085 been commented out. Unless there is activity to revive these
3086 configurations, the next release of GDB will have their sources
3087 permanently REMOVED.
3089 AMD 29k family via UDI a29k-amd-udi, udi29k
3090 A29K VxWorks a29k-*-vxworks
3091 AMD 29000 embedded, using EBMON a29k-none-none
3092 AMD 29000 embedded with COFF a29k-none-coff
3093 AMD 29000 embedded with a.out a29k-none-aout
3095 testsuite/gdb.hp/gdb.threads-hp/ directory
3097 * REMOVED configurations and files
3099 TI TMS320C80 tic80-*-*
3101 PowerPC Solaris powerpcle-*-solaris*
3102 PowerPC Windows NT powerpcle-*-cygwin32
3103 PowerPC Netware powerpc-*-netware*
3104 Harris/CXUX m88k m88*-harris-cxux*
3105 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3106 ns32k-utek-sysv* ns32k-utek-*
3107 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3108 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3109 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3110 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3111 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3113 * Changes to command line processing
3115 The new `--args' feature can be used to specify command-line arguments
3116 for the inferior from gdb's command line.
3118 * Changes to key bindings
3120 There is a new `operate-and-get-next' function bound to `C-o'.
3122 *** Changes in GDB 5.1.1
3124 Fix compile problem on DJGPP.
3126 Fix a problem with floating-point registers on the i386 being
3129 Fix to stop GDB crashing on .debug_str debug info.
3131 Numerous documentation fixes.
3133 Numerous testsuite fixes.
3135 *** Changes in GDB 5.1:
3137 * New native configurations
3139 Alpha FreeBSD alpha*-*-freebsd*
3140 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3141 MIPS GNU/Linux mips*-*-linux*
3142 MIPS SGI Irix 6.x mips*-sgi-irix6*
3143 ia64 AIX ia64-*-aix*
3144 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3148 Motorola 68HC11 and 68HC12 m68hc11-elf
3150 UltraSparc running GNU/Linux sparc64-*-linux*
3152 * OBSOLETE configurations and files
3154 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3155 Harris/CXUX m88k m88*-harris-cxux*
3156 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3157 ns32k-utek-sysv* ns32k-utek-*
3158 TI TMS320C80 tic80-*-*
3160 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3161 PowerPC Solaris powerpcle-*-solaris*
3162 PowerPC Windows NT powerpcle-*-cygwin32
3163 PowerPC Netware powerpc-*-netware*
3164 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3165 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3166 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3167 Apple Macintosh (MPW) host N/A
3169 stuff.c (Program to stuff files into a specially prepared space in kdb)
3170 kdb-start.c (Main loop for the standalone kernel debugger)
3172 Configurations that have been declared obsolete in this release have
3173 been commented out. Unless there is activity to revive these
3174 configurations, the next release of GDB will have their sources
3175 permanently REMOVED.
3177 * REMOVED configurations and files
3179 Altos 3068 m68*-altos-*
3180 Convex c1-*-*, c2-*-*
3182 ARM RISCix arm-*-* (as host)
3186 * GDB has been converted to ISO C.
3188 GDB's source code has been converted to ISO C. In particular, the
3189 sources are fully protoized, and rely on standard headers being
3194 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3196 * The MI enabled by default.
3198 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3199 revised and enabled by default. Packages which use GDB as a debugging
3200 engine behind a UI or another front end are encouraged to switch to
3201 using the GDB/MI interface, instead of the old annotations interface
3202 which is now deprecated.
3204 * Support for debugging Pascal programs.
3206 GDB now includes support for debugging Pascal programs. The following
3207 main features are supported:
3209 - Pascal-specific data types such as sets;
3211 - automatic recognition of Pascal sources based on file-name
3214 - Pascal-style display of data types, variables, and functions;
3216 - a Pascal expression parser.
3218 However, some important features are not yet supported.
3220 - Pascal string operations are not supported at all;
3222 - there are some problems with boolean types;
3224 - Pascal type hexadecimal constants are not supported
3225 because they conflict with the internal variables format;
3227 - support for Pascal objects and classes is not full yet;
3229 - unlike Pascal, GDB is case-sensitive for symbol names.
3231 * Changes in completion.
3233 Commands such as `shell', `run' and `set args', which pass arguments
3234 to inferior programs, now complete on file names, similar to what
3235 users expect at the shell prompt.
3237 Commands which accept locations, such as `disassemble', `print',
3238 `breakpoint', `until', etc. now complete on filenames as well as
3239 program symbols. Thus, if you type "break foob TAB", and the source
3240 files linked into the programs include `foobar.c', that file name will
3241 be one of the candidates for completion. However, file names are not
3242 considered for completion after you typed a colon that delimits a file
3243 name from a name of a function in that file, as in "break foo.c:bar".
3245 `set demangle-style' completes on available demangling styles.
3247 * New platform-independent commands:
3249 It is now possible to define a post-hook for a command as well as a
3250 hook that runs before the command. For more details, see the
3251 documentation of `hookpost' in the GDB manual.
3253 * Changes in GNU/Linux native debugging.
3255 Support for debugging multi-threaded programs has been completely
3256 revised for all platforms except m68k and sparc. You can now debug as
3257 many threads as your system allows you to have.
3259 Attach/detach is supported for multi-threaded programs.
3261 Support for SSE registers was added for x86. This doesn't work for
3262 multi-threaded programs though.
3264 * Changes in MIPS configurations.
3266 Multi-arch support is enabled for all MIPS configurations.
3268 GDB can now be built as native debugger on SGI Irix 6.x systems for
3269 debugging n32 executables. (Debugging 64-bit executables is not yet
3272 * Unified support for hardware watchpoints in all x86 configurations.
3274 Most (if not all) native x86 configurations support hardware-assisted
3275 breakpoints and watchpoints in a unified manner. This support
3276 implements debug register sharing between watchpoints, which allows to
3277 put a virtually infinite number of watchpoints on the same address,
3278 and also supports watching regions up to 16 bytes with several debug
3281 The new maintenance command `maintenance show-debug-regs' toggles
3282 debugging print-outs in functions that insert, remove, and test
3283 watchpoints and hardware breakpoints.
3285 * Changes in the DJGPP native configuration.
3287 New command ``info dos sysinfo'' displays assorted information about
3288 the CPU, OS, memory, and DPMI server.
3290 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3291 display information about segment descriptors stored in GDT, LDT, and
3294 New commands ``info dos pde'' and ``info dos pte'' display entries
3295 from Page Directory and Page Tables (for now works with CWSDPMI only).
3296 New command ``info dos address-pte'' displays the Page Table entry for
3297 a given linear address.
3299 GDB can now pass command lines longer than 126 characters to the
3300 program being debugged (requires an update to the libdbg.a library
3301 which is part of the DJGPP development kit).
3303 DWARF2 debug info is now supported.
3305 It is now possible to `step' and `next' through calls to `longjmp'.
3307 * Changes in documentation.
3309 All GDB documentation was converted to GFDL, the GNU Free
3310 Documentation License.
3312 Tracepoints-related commands are now fully documented in the GDB
3315 TUI, the Text-mode User Interface, is now documented in the manual.
3317 Tracepoints-related commands are now fully documented in the GDB
3320 The "GDB Internals" manual now has an index. It also includes
3321 documentation of `ui_out' functions, GDB coding standards, x86
3322 hardware watchpoints, and memory region attributes.
3324 * GDB's version number moved to ``version.in''
3326 The Makefile variable VERSION has been replaced by the file
3327 ``version.in''. People creating GDB distributions should update the
3328 contents of this file.
3332 GUD support is now a standard part of the EMACS distribution.
3334 *** Changes in GDB 5.0:
3336 * Improved support for debugging FP programs on x86 targets
3338 Unified and much-improved support for debugging floating-point
3339 programs on all x86 targets. In particular, ``info float'' now
3340 displays the FP registers in the same format on all x86 targets, with
3341 greater level of detail.
3343 * Improvements and bugfixes in hardware-assisted watchpoints
3345 It is now possible to watch array elements, struct members, and
3346 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3347 on x86 targets no longer erroneously trigger when the address is
3350 * Improvements in the native DJGPP version of GDB
3352 The distribution now includes all the scripts and auxiliary files
3353 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3354 machines ``out of the box''.
3356 The DJGPP version can now debug programs that use signals. It is
3357 possible to catch signals that happened in the debuggee, deliver
3358 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3359 would kill the program being debugged.) Programs that hook hardware
3360 interrupts (keyboard, timer, etc.) can also be debugged.
3362 It is now possible to debug DJGPP programs that redirect their
3363 standard handles or switch them to raw (as opposed to cooked) mode, or
3364 even close them. The command ``run < foo > bar'' works as expected,
3365 and ``info terminal'' reports useful information about the debuggee's
3366 terminal, including raw/cooked mode, redirection, etc.
3368 The DJGPP version now uses termios functions for console I/O, which
3369 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3372 DOS-style file names with drive letters are now fully supported by
3375 It is now possible to debug DJGPP programs that switch their working
3376 directory. It is also possible to rerun the debuggee any number of
3377 times without restarting GDB; thus, you can use the same setup,
3378 breakpoints, etc. for many debugging sessions.
3380 * New native configurations
3382 ARM GNU/Linux arm*-*-linux*
3383 PowerPC GNU/Linux powerpc-*-linux*
3387 Motorola MCore mcore-*-*
3388 x86 VxWorks i[3456]86-*-vxworks*
3389 PowerPC VxWorks powerpc-*-vxworks*
3390 TI TMS320C80 tic80-*-*
3392 * OBSOLETE configurations
3394 Altos 3068 m68*-altos-*
3395 Convex c1-*-*, c2-*-*
3397 ARM RISCix arm-*-* (as host)
3400 Configurations that have been declared obsolete will be commented out,
3401 but the code will be left in place. If there is no activity to revive
3402 these configurations before the next release of GDB, the sources will
3403 be permanently REMOVED.
3405 * Gould support removed
3407 Support for the Gould PowerNode and NP1 has been removed.
3409 * New features for SVR4
3411 On SVR4 native platforms (such as Solaris), if you attach to a process
3412 without first loading a symbol file, GDB will now attempt to locate and
3413 load symbols from the running process's executable file.
3415 * Many C++ enhancements
3417 C++ support has been greatly improved. Overload resolution now works properly
3418 in almost all cases. RTTI support is on the way.
3420 * Remote targets can connect to a sub-program
3422 A popen(3) style serial-device has been added. This device starts a
3423 sub-process (such as a stand-alone simulator) and then communicates
3424 with that. The sub-program to run is specified using the syntax
3425 ``|<program> <args>'' vis:
3427 (gdb) set remotedebug 1
3428 (gdb) target extended-remote |mn10300-elf-sim program-args
3430 * MIPS 64 remote protocol
3432 A long standing bug in the mips64 remote protocol where by GDB
3433 expected certain 32 bit registers (ex SR) to be transfered as 32
3434 instead of 64 bits has been fixed.
3436 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3437 added to provide backward compatibility with older versions of GDB.
3439 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3441 The command ``set remotebinarydownload'' command has been replaced by
3442 ``set remote X-packet''. Other commands in ``set remote'' family
3443 include ``set remote P-packet''.
3445 * Breakpoint commands accept ranges.
3447 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3448 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3449 ``tracepoint passcount'' also accepts a range of tracepoints.
3451 * ``apropos'' command added.
3453 The ``apropos'' command searches through command names and
3454 documentation strings, printing out matches, making it much easier to
3455 try to find a command that does what you are looking for.
3459 A new machine oriented interface (MI) has been added to GDB. This
3460 interface is designed for debug environments running GDB as a separate
3461 process. This is part of the long term libGDB project. See the
3462 "GDB/MI" chapter of the GDB manual for further information. It can be
3463 enabled by configuring with:
3465 .../configure --enable-gdbmi
3467 *** Changes in GDB-4.18:
3469 * New native configurations
3471 HP-UX 10.20 hppa*-*-hpux10.20
3472 HP-UX 11.x hppa*-*-hpux11.0*
3473 M68K GNU/Linux m68*-*-linux*
3477 Fujitsu FR30 fr30-*-elf*
3478 Intel StrongARM strongarm-*-*
3479 Mitsubishi D30V d30v-*-*
3481 * OBSOLETE configurations
3483 Gould PowerNode, NP1 np1-*-*, pn-*-*
3485 Configurations that have been declared obsolete will be commented out,
3486 but the code will be left in place. If there is no activity to revive
3487 these configurations before the next release of GDB, the sources will
3488 be permanently REMOVED.
3492 As a compatibility experiment, GDB's source files buildsym.h and
3493 buildsym.c have been converted to pure standard C, no longer
3494 containing any K&R compatibility code. We believe that all systems in
3495 use today either come with a standard C compiler, or have a GCC port
3496 available. If this is not true, please report the affected
3497 configuration to bug-gdb@gnu.org immediately. See the README file for
3498 information about getting a standard C compiler if you don't have one
3503 GDB now uses readline 2.2.
3505 * set extension-language
3507 You can now control the mapping between filename extensions and source
3508 languages by using the `set extension-language' command. For instance,
3509 you can ask GDB to treat .c files as C++ by saying
3510 set extension-language .c c++
3511 The command `info extensions' lists all of the recognized extensions
3512 and their associated languages.
3514 * Setting processor type for PowerPC and RS/6000
3516 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3517 you can use the `set processor' command to specify what variant of the
3518 PowerPC family you are debugging. The command
3522 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3523 following PowerPC and RS6000 variants:
3525 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3526 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3528 403GC IBM PowerPC 403GC
3529 505 Motorola PowerPC 505
3530 860 Motorola PowerPC 860 or 850
3531 601 Motorola PowerPC 601
3532 602 Motorola PowerPC 602
3533 603 Motorola/IBM PowerPC 603 or 603e
3534 604 Motorola PowerPC 604 or 604e
3535 750 Motorola/IBM PowerPC 750 or 750
3537 At the moment, this command just tells GDB what to name the
3538 special-purpose processor registers. Since almost all the affected
3539 registers are inaccessible to user-level programs, this command is
3540 only useful for remote debugging in its present form.
3544 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3545 more extensive support for HP-UX. Added features include shared
3546 library support, kernel threads and hardware watchpoints for 11.00,
3547 support for HP's ANSI C and C++ compilers, and a compatibility mode
3548 for xdb and dbx commands.
3552 HP's donation includes the new concept of catchpoints, which is a
3553 generalization of the old catch command. On HP-UX, it is now possible
3554 to catch exec, fork, and vfork, as well as library loading.
3556 This means that the existing catch command has changed; its first
3557 argument now specifies the type of catch to be set up. See the
3558 output of "help catch" for a list of catchpoint types.
3560 * Debugging across forks
3562 On HP-UX, you can choose which process to debug when a fork() happens
3567 HP has donated a curses-based terminal user interface (TUI). To get
3568 it, build with --enable-tui. Although this can be enabled for any
3569 configuration, at present it only works for native HP debugging.
3571 * GDB remote protocol additions
3573 A new protocol packet 'X' that writes binary data is now available.
3574 Default behavior is to try 'X', then drop back to 'M' if the stub
3575 fails to respond. The settable variable `remotebinarydownload'
3576 allows explicit control over the use of 'X'.
3578 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3579 full 64-bit address. The command
3581 set remoteaddresssize 32
3583 can be used to revert to the old behaviour. For existing remote stubs
3584 the change should not be noticed, as the additional address information
3587 In order to assist in debugging stubs, you may use the maintenance
3588 command `packet' to send any text string to the stub. For instance,
3590 maint packet heythere
3592 sends the packet "$heythere#<checksum>". Note that it is very easy to
3593 disrupt a debugging session by sending the wrong packet at the wrong
3596 The compare-sections command allows you to compare section data on the
3597 target to what is in the executable file without uploading or
3598 downloading, by comparing CRC checksums.
3600 * Tracing can collect general expressions
3602 You may now collect general expressions at tracepoints. This requires
3603 further additions to the target-side stub; see tracepoint.c and
3604 doc/agentexpr.texi for further details.
3606 * mask-address variable for Mips
3608 For Mips targets, you may control the zeroing of the upper 32 bits of
3609 a 64-bit address by entering `set mask-address on'. This is mainly
3610 of interest to users of embedded R4xxx and R5xxx processors.
3612 * Higher serial baud rates
3614 GDB's serial code now allows you to specify baud rates 57600, 115200,
3615 230400, and 460800 baud. (Note that your host system may not be able
3616 to achieve all of these rates.)
3620 The i960 configuration now includes an initial implementation of a
3621 builtin simulator, contributed by Jim Wilson.
3624 *** Changes in GDB-4.17:
3626 * New native configurations
3628 Alpha GNU/Linux alpha*-*-linux*
3629 Unixware 2.x i[3456]86-unixware2*
3630 Irix 6.x mips*-sgi-irix6*
3631 PowerPC GNU/Linux powerpc-*-linux*
3632 PowerPC Solaris powerpcle-*-solaris*
3633 Sparc GNU/Linux sparc-*-linux*
3634 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3638 Argonaut Risc Chip (ARC) arc-*-*
3639 Hitachi H8/300S h8300*-*-*
3640 Matsushita MN10200 w/simulator mn10200-*-*
3641 Matsushita MN10300 w/simulator mn10300-*-*
3642 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3643 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3644 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3645 Mitsubishi D10V w/simulator d10v-*-*
3646 Mitsubishi M32R/D w/simulator m32r-*-elf*
3647 Tsqware Sparclet sparclet-*-*
3648 NEC V850 w/simulator v850-*-*
3650 * New debugging protocols
3652 ARM with RDI protocol arm*-*-*
3653 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3654 DDB and LSI variants of PMON protocol mips*-*-*
3655 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3656 PowerPC with SDS protocol powerpc{,le}-*-eabi
3657 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3661 All configurations can now understand and use the DWARF 2 debugging
3662 format. The choice is automatic, if the symbol file contains DWARF 2
3667 GDB now includes basic Java language support. This support is
3668 only useful with Java compilers that produce native machine code.
3670 * solib-absolute-prefix and solib-search-path
3672 For SunOS and SVR4 shared libraries, you may now set the prefix for
3673 loading absolute shared library symbol files, and the search path for
3674 locating non-absolute shared library symbol files.
3676 * Live range splitting
3678 GDB can now effectively debug code for which GCC has performed live
3679 range splitting as part of its optimization. See gdb/doc/LRS for
3680 more details on the expected format of the stabs information.
3684 GDB's support for the GNU Hurd, including thread debugging, has been
3685 updated to work with current versions of the Hurd.
3689 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3690 instruction set. ARM GDB automatically detects when Thumb
3691 instructions are in use, and adjusts disassembly and backtracing
3696 GDB's MIPS target configurations now handle the MIP16 16-bit
3701 GDB now includes support for overlays; if an executable has been
3702 linked such that multiple sections are based at the same address, GDB
3703 will decide which section to use for symbolic info. You can choose to
3704 control the decision manually, using overlay commands, or implement
3705 additional target-side support and use "overlay load-target" to bring
3706 in the overlay mapping. Do "help overlay" for more detail.
3710 The command "info symbol <address>" displays information about
3711 the symbol at the specified address.
3715 The standard remote protocol now includes an extension that allows
3716 asynchronous collection and display of trace data. This requires
3717 extensive support in the target-side debugging stub. Tracing mode
3718 includes a new interaction mode in GDB and new commands: see the
3719 file tracepoint.c for more details.
3723 Configurations for embedded MIPS now include a simulator contributed
3724 by Cygnus Solutions. The simulator supports the instruction sets
3725 of most MIPS variants.
3729 Sparc configurations may now include the ERC32 simulator contributed
3730 by the European Space Agency. The simulator is not built into
3731 Sparc targets by default; configure with --enable-sim to include it.
3735 For target configurations that may include multiple variants of a
3736 basic architecture (such as MIPS and SH), you may now set the
3737 architecture explicitly. "set arch" sets, "info arch" lists
3738 the possible architectures.
3740 *** Changes in GDB-4.16:
3742 * New native configurations
3744 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3745 M68K NetBSD m68k-*-netbsd*
3746 PowerPC AIX 4.x powerpc-*-aix*
3747 PowerPC MacOS powerpc-*-macos*
3748 PowerPC Windows NT powerpcle-*-cygwin32
3749 RS/6000 AIX 4.x rs6000-*-aix4*
3753 ARM with RDP protocol arm-*-*
3754 I960 with MON960 i960-*-coff
3755 MIPS VxWorks mips*-*-vxworks*
3756 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3757 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3759 Matra Sparclet sparclet-*-*
3763 The powerpc-eabi configuration now includes the PSIM simulator,
3764 contributed by Andrew Cagney, with assistance from Mike Meissner.
3765 PSIM is a very elaborate model of the PowerPC, including not only
3766 basic instruction set execution, but also details of execution unit
3767 performance and I/O hardware. See sim/ppc/README for more details.
3771 GDB now works with Solaris 2.5.
3773 * Windows 95/NT native
3775 GDB will now work as a native debugger on Windows 95 and Windows NT.
3776 To build it from source, you must use the "gnu-win32" environment,
3777 which uses a DLL to emulate enough of Unix to run the GNU tools.
3778 Further information, binaries, and sources are available at
3779 ftp.cygnus.com, under pub/gnu-win32.
3781 * dont-repeat command
3783 If a user-defined command includes the command `dont-repeat', then the
3784 command will not be repeated if the user just types return. This is
3785 useful if the command is time-consuming to run, so that accidental
3786 extra keystrokes don't run the same command many times.
3788 * Send break instead of ^C
3790 The standard remote protocol now includes an option to send a break
3791 rather than a ^C to the target in order to interrupt it. By default,
3792 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3794 * Remote protocol timeout
3796 The standard remote protocol includes a new variable `remotetimeout'
3797 that allows you to set the number of seconds before GDB gives up trying
3798 to read from the target. The default value is 2.
3800 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3802 By default GDB will automatically keep track of objects as they are
3803 loaded and unloaded by the dynamic linker. By using the command `set
3804 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3805 when shared library events occur, thus allowing you to set breakpoints
3806 in shared libraries which are explicitly loaded by the inferior.
3808 Note this feature does not work on hpux8. On hpux9 you must link
3809 /usr/lib/end.o into your program. This feature should work
3810 automatically on hpux10.
3812 * Irix 5.x hardware watchpoint support
3814 Irix 5 configurations now support the use of hardware watchpoints.
3816 * Mips protocol "SYN garbage limit"
3818 When debugging a Mips target using the `target mips' protocol, you
3819 may set the number of characters that GDB will ignore by setting
3820 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3821 every character. The default value is 1050.
3823 * Recording and replaying remote debug sessions
3825 If you set `remotelogfile' to the name of a file, gdb will write to it
3826 a recording of a remote debug session. This recording may then be
3827 replayed back to gdb using "gdbreplay". See gdbserver/README for
3828 details. This is useful when you have a problem with GDB while doing
3829 remote debugging; you can make a recording of the session and send it
3830 to someone else, who can then recreate the problem.
3832 * Speedups for remote debugging
3834 GDB includes speedups for downloading and stepping MIPS systems using
3835 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3836 and more efficient S-record downloading.
3838 * Memory use reductions and statistics collection
3840 GDB now uses less memory and reports statistics about memory usage.
3841 Try the `maint print statistics' command, for example.
3843 *** Changes in GDB-4.15:
3845 * Psymtabs for XCOFF
3847 The symbol reader for AIX GDB now uses partial symbol tables. This
3848 can greatly improve startup time, especially for large executables.
3850 * Remote targets use caching
3852 Remote targets now use a data cache to speed up communication with the
3853 remote side. The data cache could lead to incorrect results because
3854 it doesn't know about volatile variables, thus making it impossible to
3855 debug targets which use memory mapped I/O devices. `set remotecache
3856 off' turns the the data cache off.
3858 * Remote targets may have threads
3860 The standard remote protocol now includes support for multiple threads
3861 in the target system, using new protocol commands 'H' and 'T'. See
3862 gdb/remote.c for details.
3866 If GDB is configured with `--enable-netrom', then it will include
3867 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3868 acts as though it is a bank of ROM on the target board, but you can
3869 write into it over the network. GDB's support consists only of
3870 support for fast loading into the emulated ROM; to debug, you must use
3871 another protocol, such as standard remote protocol. The usual
3872 sequence is something like
3874 target nrom <netrom-hostname>
3876 target remote <netrom-hostname>:1235
3880 GDB now includes support for the Apple Macintosh, as a host only. It
3881 may be run as either an MPW tool or as a standalone application, and
3882 it can debug through the serial port. All the usual GDB commands are
3883 available, but to the target command, you must supply "serial" as the
3884 device type instead of "/dev/ttyXX". See mpw-README in the main
3885 directory for more information on how to build. The MPW configuration
3886 scripts */mpw-config.in support only a few targets, and only the
3887 mips-idt-ecoff target has been tested.
3891 GDB configuration now uses autoconf. This is not user-visible,
3892 but does simplify configuration and building.
3896 GDB now supports hpux10.
3898 *** Changes in GDB-4.14:
3900 * New native configurations
3902 x86 FreeBSD i[345]86-*-freebsd
3903 x86 NetBSD i[345]86-*-netbsd
3904 NS32k NetBSD ns32k-*-netbsd
3905 Sparc NetBSD sparc-*-netbsd
3909 A29K VxWorks a29k-*-vxworks
3910 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3911 CPU32 EST-300 emulator m68*-*-est*
3912 PowerPC ELF powerpc-*-elf
3915 * Alpha OSF/1 support for procfs
3917 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3918 possible to attach to running processes. As the mounting of the /proc
3919 filesystem is optional on the Alpha, GDB automatically determines
3920 the availability of /proc during startup. This can lead to problems
3921 if /proc is unmounted after GDB has been started.
3923 * Arguments to user-defined commands
3925 User commands may accept up to 10 arguments separated by whitespace.
3926 Arguments are accessed within the user command via $arg0..$arg9. A
3929 print $arg0 + $arg1 + $arg2
3931 To execute the command use:
3934 Defines the command "adder" which prints the sum of its three arguments.
3935 Note the arguments are text substitutions, so they may reference variables,
3936 use complex expressions, or even perform inferior function calls.
3938 * New `if' and `while' commands
3940 This makes it possible to write more sophisticated user-defined
3941 commands. Both commands take a single argument, which is the
3942 expression to evaluate, and must be followed by the commands to
3943 execute, one per line, if the expression is nonzero, the list being
3944 terminated by the word `end'. The `if' command list may include an
3945 `else' word, which causes the following commands to be executed only
3946 if the expression is zero.
3948 * Fortran source language mode
3950 GDB now includes partial support for Fortran 77. It will recognize
3951 Fortran programs and can evaluate a subset of Fortran expressions, but
3952 variables and functions may not be handled correctly. GDB will work
3953 with G77, but does not yet know much about symbols emitted by other
3956 * Better HPUX support
3958 Most debugging facilities now work on dynamic executables for HPPAs
3959 running hpux9 or later. You can attach to running dynamically linked
3960 processes, but by default the dynamic libraries will be read-only, so
3961 for instance you won't be able to put breakpoints in them. To change
3962 that behavior do the following before running the program:
3968 This will cause the libraries to be mapped private and read-write.
3969 To revert to the normal behavior, do this:
3975 You cannot set breakpoints or examine data in the library until after
3976 the library is loaded if the function/data symbols do not have
3979 GDB can now also read debug symbols produced by the HP C compiler on
3980 HPPAs (sorry, no C++, Fortran or 68k support).
3982 * Target byte order now dynamically selectable
3984 You can choose which byte order to use with a target system, via the
3985 commands "set endian big" and "set endian little", and you can see the
3986 current setting by using "show endian". You can also give the command
3987 "set endian auto", in which case GDB will use the byte order
3988 associated with the executable. Currently, only embedded MIPS
3989 configurations support dynamic selection of target byte order.
3991 * New DOS host serial code
3993 This version uses DPMI interrupts to handle buffered I/O, so you
3994 no longer need to run asynctsr when debugging boards connected to
3997 *** Changes in GDB-4.13:
3999 * New "complete" command
4001 This lists all the possible completions for the rest of the line, if it
4002 were to be given as a command itself. This is intended for use by emacs.
4004 * Trailing space optional in prompt
4006 "set prompt" no longer adds a space for you after the prompt you set. This
4007 allows you to set a prompt which ends in a space or one that does not.
4009 * Breakpoint hit counts
4011 "info break" now displays a count of the number of times the breakpoint
4012 has been hit. This is especially useful in conjunction with "ignore"; you
4013 can ignore a large number of breakpoint hits, look at the breakpoint info
4014 to see how many times the breakpoint was hit, then run again, ignoring one
4015 less than that number, and this will get you quickly to the last hit of
4018 * Ability to stop printing at NULL character
4020 "set print null-stop" will cause GDB to stop printing the characters of
4021 an array when the first NULL is encountered. This is useful when large
4022 arrays actually contain only short strings.
4024 * Shared library breakpoints
4026 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4027 breakpoints in shared libraries before the executable is run.
4029 * Hardware watchpoints
4031 There is a new hardware breakpoint for the watch command for sparclite
4032 targets. See gdb/sparclite/hw_breakpoint.note.
4034 Hardware watchpoints are also now supported under GNU/Linux.
4038 Annotations have been added. These are for use with graphical interfaces,
4039 and are still experimental. Currently only gdba.el uses these.
4041 * Improved Irix 5 support
4043 GDB now works properly with Irix 5.2.
4045 * Improved HPPA support
4047 GDB now works properly with the latest GCC and GAS.
4049 * New native configurations
4051 Sequent PTX4 i[34]86-sequent-ptx4
4052 HPPA running OSF/1 hppa*-*-osf*
4053 Atari TT running SVR4 m68*-*-sysv4*
4054 RS/6000 LynxOS rs6000-*-lynxos*
4058 OS/9000 i[34]86-*-os9k
4059 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4062 * Hitachi SH7000 and E7000-PC ICE support
4064 There is now support for communicating with the Hitachi E7000-PC ICE.
4065 This is available automatically when GDB is configured for the SH.
4069 As usual, a variety of small fixes and improvements, both generic
4070 and configuration-specific. See the ChangeLog for more detail.
4072 *** Changes in GDB-4.12:
4074 * Irix 5 is now supported
4078 GDB-4.12 on the HPPA has a number of changes which make it unable
4079 to debug the output from the currently released versions of GCC and
4080 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4081 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4082 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4085 *** Changes in GDB-4.11:
4087 * User visible changes:
4091 The "set remotedebug" option is now consistent between the mips remote
4092 target, remote targets using the gdb-specific protocol, UDI (AMD's
4093 debug protocol for the 29k) and the 88k bug monitor. It is now an
4094 integer specifying a debug level (normally 0 or 1, but 2 means more
4095 debugging info for the mips target).
4097 * DEC Alpha native support
4099 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4100 debug info, but GDB works fairly well with the DEC compiler and should
4101 work with a future GCC release. See the README file for a few
4102 Alpha-specific notes.
4104 * Preliminary thread implementation
4106 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4108 * LynxOS native and target support for 386
4110 This release has been hosted on LynxOS 2.2, and also can be configured
4111 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4114 * Improvements in C++ mangling/demangling.
4116 This release has much better g++ debugging, specifically in name
4117 mangling/demangling, virtual function calls, print virtual table,
4118 call methods, ...etc.
4120 *** Changes in GDB-4.10:
4122 * User visible changes:
4124 Remote debugging using the GDB-specific (`target remote') protocol now
4125 supports the `load' command. This is only useful if you have some
4126 other way of getting the stub to the target system, and you can put it
4127 somewhere in memory where it won't get clobbered by the download.
4129 Filename completion now works.
4131 When run under emacs mode, the "info line" command now causes the
4132 arrow to point to the line specified. Also, "info line" prints
4133 addresses in symbolic form (as well as hex).
4135 All vxworks based targets now support a user settable option, called
4136 vxworks-timeout. This option represents the number of seconds gdb
4137 should wait for responses to rpc's. You might want to use this if
4138 your vxworks target is, perhaps, a slow software simulator or happens
4139 to be on the far side of a thin network line.
4143 This release contains support for using a DEC alpha as a GDB host for
4144 cross debugging. Native alpha debugging is not supported yet.
4147 *** Changes in GDB-4.9:
4151 This is the first GDB release which is accompanied by a matching testsuite.
4152 The testsuite requires installation of dejagnu, which should be available
4153 via ftp from most sites that carry GNU software.
4157 'Cfront' style demangling has had its name changed to 'ARM' style, to
4158 emphasize that it was written from the specifications in the C++ Annotated
4159 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4160 disclaimers, it still generated too much confusion with users attempting to
4161 use gdb with AT&T cfront.
4165 GDB now uses a standard remote interface to a simulator library.
4166 So far, the library contains simulators for the Zilog Z8001/2, the
4167 Hitachi H8/300, H8/500 and Super-H.
4169 * New targets supported
4171 H8/300 simulator h8300-hitachi-hms or h8300hms
4172 H8/500 simulator h8500-hitachi-hms or h8500hms
4173 SH simulator sh-hitachi-hms or sh
4174 Z8000 simulator z8k-zilog-none or z8ksim
4175 IDT MIPS board over serial line mips-idt-ecoff
4177 Cross-debugging to GO32 targets is supported. It requires a custom
4178 version of the i386-stub.c module which is integrated with the
4179 GO32 memory extender.
4181 * New remote protocols
4183 MIPS remote debugging protocol.
4185 * New source languages supported
4187 This version includes preliminary support for Chill, a Pascal like language
4188 used by telecommunications companies. Chill support is also being integrated
4189 into the GNU compiler, but we don't know when it will be publically available.
4192 *** Changes in GDB-4.8:
4194 * HP Precision Architecture supported
4196 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4197 version of this support was available as a set of patches from the
4198 University of Utah. GDB does not support debugging of programs
4199 compiled with the HP compiler, because HP will not document their file
4200 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4201 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4203 Many problems in the preliminary version have been fixed.
4205 * Faster and better demangling
4207 We have improved template demangling and fixed numerous bugs in the GNU style
4208 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4209 character types (wchar_t) are now supported. Demangling of each symbol is now
4210 only done once, and is cached when the symbol table for a file is read in.
4211 This results in a small increase in memory usage for C programs, a moderate
4212 increase in memory usage for C++ programs, and a fantastic speedup in
4215 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4216 from the specifications in the Annotated Reference Manual, which AT&T's
4217 compiler does not actually implement.
4219 * G++ multiple inheritance compiler problem
4221 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4222 inheritance lattices was reworked to properly discover ambiguities. We
4223 recently found an example which causes this new algorithm to fail in a
4224 very subtle way, producing bad debug information for those classes.
4225 The file 'gcc.patch' (in this directory) can be applied to gcc to
4226 circumvent the problem. A future GCC release will contain a complete
4229 The previous G++ debug info problem (mentioned below for the gdb-4.7
4230 release) is fixed in gcc version 2.3.2.
4232 * Improved configure script
4234 The `configure' script will now attempt to guess your system type if
4235 you don't supply a host system type. The old scheme of supplying a
4236 host system triplet is preferable over using this. All the magic is
4237 done in the new `config.guess' script. Examine it for details.
4239 We have also brought our configure script much more in line with the FSF's
4240 version. It now supports the --with-xxx options. In particular,
4241 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4242 The resulting GDB will not be able to read arbitrary object file formats --
4243 only the format ``expected'' to be used on the configured target system.
4244 We hope to make this the default in a future release.
4246 * Documentation improvements
4248 There's new internal documentation on how to modify GDB, and how to
4249 produce clean changes to the code. We implore people to read it
4250 before submitting changes.
4252 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4253 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4254 `info' files are also provided. To build `info' files from scratch,
4255 you will need the latest `makeinfo' release, which will be available in
4256 a future texinfo-X.Y release.
4258 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4259 We're not sure exactly which versions have this problem, but it has
4260 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4261 or better. If that isn't possible, there is a patch in
4262 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4263 around this problem.
4267 GDB now supports array constants that can be used in expressions typed in by
4268 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4269 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4272 The new directory `gdb/sparclite' contains a program that demonstrates
4273 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4275 * New native hosts supported
4277 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4278 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4280 * New targets supported
4282 AMD 29k family via UDI a29k-amd-udi or udi29k
4284 * New file formats supported
4286 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4287 HPUX core files, and SCO 3.2v2 core files.
4291 Attaching to processes now works again; thanks for the many bug reports.
4293 We have also stomped on a bunch of core dumps caused by
4294 printf_filtered("%s") problems.
4296 We eliminated a copyright problem on the rpc and ptrace header files
4297 for VxWorks, which was discovered at the last minute during the 4.7
4298 release. You should now be able to build a VxWorks GDB.
4300 You can now interrupt gdb while an attached process is running. This
4301 will cause the attached process to stop, and give control back to GDB.
4303 We fixed problems caused by using too many file descriptors
4304 for reading symbols from object files and libraries. This was
4305 especially a problem for programs that used many (~100) shared
4308 The `step' command now only enters a subroutine if there is line number
4309 information for the subroutine. Otherwise it acts like the `next'
4310 command. Previously, `step' would enter subroutines if there was
4311 any debugging information about the routine. This avoids problems
4312 when using `cc -g1' on MIPS machines.
4314 * Internal improvements
4316 GDB's internal interfaces have been improved to make it easier to support
4317 debugging of multiple languages in the future.
4319 GDB now uses a common structure for symbol information internally.
4320 Minimal symbols (derived from linkage symbols in object files), partial
4321 symbols (from a quick scan of debug information), and full symbols
4322 contain a common subset of information, making it easier to write
4323 shared code that handles any of them.
4325 * New command line options
4327 We now accept --silent as an alias for --quiet.
4331 The memory-mapped-malloc library is now licensed under the GNU Library
4332 General Public License.
4334 *** Changes in GDB-4.7:
4336 * Host/native/target split
4338 GDB has had some major internal surgery to untangle the support for
4339 hosts and remote targets. Now, when you configure GDB for a remote
4340 target, it will no longer load in all of the support for debugging
4341 local programs on the host. When fully completed and tested, this will
4342 ensure that arbitrary host/target combinations are possible.
4344 The primary conceptual shift is to separate the non-portable code in
4345 GDB into three categories. Host specific code is required any time GDB
4346 is compiled on that host, regardless of the target. Target specific
4347 code relates to the peculiarities of the target, but can be compiled on
4348 any host. Native specific code is everything else: it can only be
4349 built when the host and target are the same system. Child process
4350 handling and core file support are two common `native' examples.
4352 GDB's use of /proc for controlling Unix child processes is now cleaner.
4353 It has been split out into a single module under the `target_ops' vector,
4354 plus two native-dependent functions for each system that uses /proc.
4356 * New hosts supported
4358 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4359 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4360 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4362 * New targets supported
4364 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4365 68030 and CPU32 m68030-*-*, m68332-*-*
4367 * New native hosts supported
4369 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4370 (386bsd is not well tested yet)
4371 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4373 * New file formats supported
4375 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4376 supports reading of `a.out.adobe' object files, which are an a.out
4377 format extended with minimal information about multiple sections.
4381 `show copying' is the same as the old `info copying'.
4382 `show warranty' is the same as `info warrantee'.
4383 These were renamed for consistency. The old commands continue to work.
4385 `info handle' is a new alias for `info signals'.
4387 You can now define pre-command hooks, which attach arbitrary command
4388 scripts to any command. The commands in the hook will be executed
4389 prior to the user's command. You can also create a hook which will be
4390 executed whenever the program stops. See gdb.texinfo.
4394 We now deal with Cfront style name mangling, and can even extract type
4395 info from mangled symbols. GDB can automatically figure out which
4396 symbol mangling style your C++ compiler uses.
4398 Calling of methods and virtual functions has been improved as well.
4402 The crash that occured when debugging Sun Ansi-C compiled binaries is
4403 fixed. This was due to mishandling of the extra N_SO stabs output
4406 We also finally got Ultrix 4.2 running in house, and fixed core file
4407 support, with help from a dozen people on the net.
4409 John M. Farrell discovered that the reason that single-stepping was so
4410 slow on all of the Mips based platforms (primarily SGI and DEC) was
4411 that we were trying to demangle and lookup a symbol used for internal
4412 purposes on every instruction that was being stepped through. Changing
4413 the name of that symbol so that it couldn't be mistaken for a C++
4414 mangled symbol sped things up a great deal.
4416 Rich Pixley sped up symbol lookups in general by getting much smarter
4417 about when C++ symbol mangling is necessary. This should make symbol
4418 completion (TAB on the command line) much faster. It's not as fast as
4419 we'd like, but it's significantly faster than gdb-4.6.
4423 A new user controllable variable 'call_scratch_address' can
4424 specify the location of a scratch area to be used when GDB
4425 calls a function in the target. This is necessary because the
4426 usual method of putting the scratch area on the stack does not work
4427 in systems that have separate instruction and data spaces.
4429 We integrated changes to support the 29k UDI (Universal Debugger
4430 Interface), but discovered at the last minute that we didn't have all
4431 of the appropriate copyright paperwork. We are working with AMD to
4432 resolve this, and hope to have it available soon.
4436 We have sped up the remote serial line protocol, especially for targets
4437 with lots of registers. It now supports a new `expedited status' ('T')
4438 message which can be used in place of the existing 'S' status message.
4439 This allows the remote stub to send only the registers that GDB
4440 needs to make a quick decision about single-stepping or conditional
4441 breakpoints, eliminating the need to fetch the entire register set for
4442 each instruction being stepped through.
4444 The GDB remote serial protocol now implements a write-through cache for
4445 registers, only re-reading the registers if the target has run.
4447 There is also a new remote serial stub for SPARC processors. You can
4448 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4449 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4450 processor with a serial port.
4454 Configure.in files have become much easier to read and modify. A new
4455 `table driven' format makes it more obvious what configurations are
4456 supported, and what files each one uses.
4460 There is a new opcodes library which will eventually contain all of the
4461 disassembly routines and opcode tables. At present, it only contains
4462 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4463 disassembler (binutils/objdump) to share these routines.
4465 The libiberty library is now copylefted under the GNU Library General
4466 Public License. This allows more liberal use, and was done so libg++
4467 can use it. This makes no difference to GDB, since the Library License
4468 grants all the rights from the General Public License.
4472 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4473 reference to the stabs symbol info used by the debugger. It is (as far
4474 as we know) the only published document on this fascinating topic. We
4475 encourage you to read it, compare it to the stabs information on your
4476 system, and send improvements on the document in general (to
4477 bug-gdb@prep.ai.mit.edu).
4479 And, of course, many bugs have been fixed.
4482 *** Changes in GDB-4.6:
4484 * Better support for C++ function names
4486 GDB now accepts as input the "demangled form" of C++ overloaded function
4487 names and member function names, and can do command completion on such names
4488 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4489 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4490 Make use of command completion, it is your friend.
4492 GDB also now accepts a variety of C++ mangled symbol formats. They are
4493 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4494 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4495 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4496 for the list of formats.
4498 * G++ symbol mangling problem
4500 Recent versions of gcc have a bug in how they emit debugging information for
4501 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4502 directory) can be applied to gcc to fix the problem. Alternatively, if you
4503 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4504 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4505 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4508 * New 'maintenance' command
4510 All of the commands related to hacking GDB internals have been moved out of
4511 the main command set, and now live behind the 'maintenance' command. This
4512 can also be abbreviated as 'mt'. The following changes were made:
4514 dump-me -> maintenance dump-me
4515 info all-breakpoints -> maintenance info breakpoints
4516 printmsyms -> maintenance print msyms
4517 printobjfiles -> maintenance print objfiles
4518 printpsyms -> maintenance print psymbols
4519 printsyms -> maintenance print symbols
4521 The following commands are new:
4523 maintenance demangle Call internal GDB demangler routine to
4524 demangle a C++ link name and prints the result.
4525 maintenance print type Print a type chain for a given symbol
4527 * Change to .gdbinit file processing
4529 We now read the $HOME/.gdbinit file before processing the argv arguments
4530 (e.g. reading symbol files or core files). This allows global parameters to
4531 be set, which will apply during the symbol reading. The ./.gdbinit is still
4532 read after argv processing.
4534 * New hosts supported
4536 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4538 GNU/Linux support i386-unknown-linux or linux
4540 We are also including code to support the HP/PA running BSD and HPUX. This
4541 is almost guaranteed not to work, as we didn't have time to test or build it
4542 for this release. We are including it so that the more adventurous (or
4543 masochistic) of you can play with it. We also had major problems with the
4544 fact that the compiler that we got from HP doesn't support the -g option.
4547 * New targets supported
4549 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4551 * More smarts about finding #include files
4553 GDB now remembers the compilation directory for all include files, and for
4554 all files from which C is generated (like yacc and lex sources). This
4555 greatly improves GDB's ability to find yacc/lex sources, and include files,
4556 especially if you are debugging your program from a directory different from
4557 the one that contains your sources.
4559 We also fixed a bug which caused difficulty with listing and setting
4560 breakpoints in include files which contain C code. (In the past, you had to
4561 try twice in order to list an include file that you hadn't looked at before.)
4563 * Interesting infernals change
4565 GDB now deals with arbitrary numbers of sections, where the symbols for each
4566 section must be relocated relative to that section's landing place in the
4567 target's address space. This work was needed to support ELF with embedded
4568 stabs used by Solaris-2.0.
4570 * Bug fixes (of course!)
4572 There have been loads of fixes for the following things:
4573 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4574 i960, stabs, DOS(GO32), procfs, etc...
4576 See the ChangeLog for details.
4578 *** Changes in GDB-4.5:
4580 * New machines supported (host and target)
4582 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4584 SGI Irix-4.x mips-sgi-irix4 or iris4
4586 * New malloc package
4588 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4589 Mmalloc is capable of handling mutiple heaps of memory. It is also
4590 capable of saving a heap to a file, and then mapping it back in later.
4591 This can be used to greatly speedup the startup of GDB by using a
4592 pre-parsed symbol table which lives in a mmalloc managed heap. For
4593 more details, please read mmalloc/mmalloc.texi.
4597 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4598 'help info proc' for details.
4600 * MIPS ecoff symbol table format
4602 The code that reads MIPS symbol table format is now supported on all hosts.
4603 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4606 * File name changes for MS-DOS
4608 Many files in the config directories have been renamed to make it easier to
4609 support GDB on MS-DOSe systems (which have very restrictive file name
4610 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4611 environment) is close to working but has some remaining problems. Note
4612 that debugging of DOS programs is not supported, due to limitations
4613 in the ``operating system'', but it can be used to host cross-debugging.
4615 * Cross byte order fixes
4617 Many fixes have been made to support cross debugging of Sparc and MIPS
4618 targets from hosts whose byte order differs.
4620 * New -mapped and -readnow options
4622 If memory-mapped files are available on your system through the 'mmap'
4623 system call, you can use the -mapped option on the `file' or
4624 `symbol-file' commands to cause GDB to write the symbols from your
4625 program into a reusable file. If the program you are debugging is
4626 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4627 Future GDB debugging sessions will notice the presence of this file,
4628 and will quickly map in symbol information from it, rather than reading
4629 the symbol table from the executable program. Using the '-mapped'
4630 option in a GDB `file' or `symbol-file' command has the same effect as
4631 starting GDB with the '-mapped' command-line option.
4633 You can cause GDB to read the entire symbol table immediately by using
4634 the '-readnow' option with any of the commands that load symbol table
4635 information (or on the GDB command line). This makes the command
4636 slower, but makes future operations faster.
4638 The -mapped and -readnow options are typically combined in order to
4639 build a `fred.syms' file that contains complete symbol information.
4640 A simple GDB invocation to do nothing but build a `.syms' file for future
4643 gdb -batch -nx -mapped -readnow programname
4645 The `.syms' file is specific to the host machine on which GDB is run.
4646 It holds an exact image of GDB's internal symbol table. It cannot be
4647 shared across multiple host platforms.
4649 * longjmp() handling
4651 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4652 siglongjmp() without losing control. This feature has not yet been ported to
4653 all systems. It currently works on many 386 platforms, all MIPS-based
4654 platforms (SGI, DECstation, etc), and Sun3/4.
4658 Preliminary work has been put in to support the new Solaris OS from Sun. At
4659 this time, it can control and debug processes, but it is not capable of
4664 As always, many many bug fixes. The major areas were with g++, and mipsread.
4665 People using the MIPS-based platforms should experience fewer mysterious
4666 crashes and trashed symbol tables.
4668 *** Changes in GDB-4.4:
4670 * New machines supported (host and target)
4672 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4674 BSD Reno on Vax vax-dec-bsd
4675 Ultrix on Vax vax-dec-ultrix
4677 * New machines supported (target)
4679 AMD 29000 embedded, using EBMON a29k-none-none
4683 GDB continues to improve its handling of C++. `References' work better.
4684 The demangler has also been improved, and now deals with symbols mangled as
4685 per the Annotated C++ Reference Guide.
4687 GDB also now handles `stabs' symbol information embedded in MIPS
4688 `ecoff' symbol tables. Since the ecoff format was not easily
4689 extensible to handle new languages such as C++, this appeared to be a
4690 good way to put C++ debugging info into MIPS binaries. This option
4691 will be supported in the GNU C compiler, version 2, when it is
4694 * New features for SVR4
4696 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4697 shared libraries. Debugging dynamically linked programs should present
4698 only minor differences from debugging statically linked programs.
4700 The `info proc' command will print out information about any process
4701 on an SVR4 system (including the one you are debugging). At the moment,
4702 it prints the address mappings of the process.
4704 If you bring up GDB on another SVR4 system, please send mail to
4705 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4707 * Better dynamic linking support in SunOS
4709 Reading symbols from shared libraries which contain debugging symbols
4710 now works properly. However, there remain issues such as automatic
4711 skipping of `transfer vector' code during function calls, which
4712 make it harder to debug code in a shared library, than to debug the
4713 same code linked statically.
4717 GDB is now using the latest `getopt' routines from the FSF. This
4718 version accepts the -- prefix for options with long names. GDB will
4719 continue to accept the old forms (-option and +option) as well.
4720 Various single letter abbreviations for options have been explicity
4721 added to the option table so that they won't get overshadowed in the
4722 future by other options that begin with the same letter.
4726 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4727 Many assorted bugs have been handled. Many more remain to be handled.
4728 See the various ChangeLog files (primarily in gdb and bfd) for details.
4731 *** Changes in GDB-4.3:
4733 * New machines supported (host and target)
4735 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4736 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4737 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4739 * Almost SCO Unix support
4741 We had hoped to support:
4742 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4743 (except for core file support), but we discovered very late in the release
4744 that it has problems with process groups that render gdb unusable. Sorry
4745 about that. I encourage people to fix it and post the fixes.
4747 * Preliminary ELF and DWARF support
4749 GDB can read ELF object files on System V Release 4, and can handle
4750 debugging records for C, in DWARF format, in ELF files. This support
4751 is preliminary. If you bring up GDB on another SVR4 system, please
4752 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4757 GDB now uses the latest `readline' library. One user-visible change
4758 is that two tabs will list possible command completions, which previously
4759 required typing M-? (meta-question mark, or ESC ?).
4763 The `stepi' bug that many of you noticed has been squashed.
4764 Many bugs in C++ have been handled. Many more remain to be handled.
4765 See the various ChangeLog files (primarily in gdb and bfd) for details.
4767 * State of the MIPS world (in case you wondered):
4769 GDB can understand the symbol tables emitted by the compilers
4770 supplied by most vendors of MIPS-based machines, including DEC. These
4771 symbol tables are in a format that essentially nobody else uses.
4773 Some versions of gcc come with an assembler post-processor called
4774 mips-tfile. This program is required if you want to do source-level
4775 debugging of gcc-compiled programs. I believe FSF does not ship
4776 mips-tfile with gcc version 1, but it will eventually come with gcc
4779 Debugging of g++ output remains a problem. g++ version 1.xx does not
4780 really support it at all. (If you're lucky, you should be able to get
4781 line numbers and stack traces to work, but no parameters or local
4782 variables.) With some work it should be possible to improve the
4785 When gcc version 2 is released, you will have somewhat better luck.
4786 However, even then you will get confusing results for inheritance and
4789 We will eventually provide full debugging of g++ output on
4790 DECstations. This will probably involve some kind of stabs-in-ecoff
4791 encapulation, but the details have not been worked out yet.
4794 *** Changes in GDB-4.2:
4796 * Improved configuration
4798 Only one copy of `configure' exists now, and it is not self-modifying.
4799 Porting BFD is simpler.
4803 The `step' and `next' commands now only stop at the first instruction
4804 of a source line. This prevents the multiple stops that used to occur
4805 in switch statements, for-loops, etc. `Step' continues to stop if a
4806 function that has debugging information is called within the line.
4810 Lots of small bugs fixed. More remain.
4812 * New host supported (not target)
4814 Intel 386 PC clone running Mach i386-none-mach
4817 *** Changes in GDB-4.1:
4819 * Multiple source language support
4821 GDB now has internal scaffolding to handle several source languages.
4822 It determines the type of each source file from its filename extension,
4823 and will switch expression parsing and number formatting to match the
4824 language of the function in the currently selected stack frame.
4825 You can also specifically set the language to be used, with
4826 `set language c' or `set language modula-2'.
4830 GDB now has preliminary support for the GNU Modula-2 compiler,
4831 currently under development at the State University of New York at
4832 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4833 continue through the fall of 1991 and into 1992.
4835 Other Modula-2 compilers are currently not supported, and attempting to
4836 debug programs compiled with them will likely result in an error as the
4837 symbol table is read. Feel free to work on it, though!
4839 There are hooks in GDB for strict type checking and range checking,
4840 in the `Modula-2 philosophy', but they do not currently work.
4844 GDB can now write to executable and core files (e.g. patch
4845 a variable's value). You must turn this switch on, specify
4846 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4847 by assigning a new value to a variable. Modifications take
4850 * Automatic SunOS shared library reading
4852 When you run your program, GDB automatically determines where its
4853 shared libraries (if any) have been loaded, and reads their symbols.
4854 The `share' command is no longer needed. This also works when
4855 examining core files.
4859 You can specify the number of lines that the `list' command shows.
4862 * New machines supported (host and target)
4864 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4865 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4866 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4868 * New hosts supported (not targets)
4870 IBM RT/PC: romp-ibm-aix or rtpc
4872 * New targets supported (not hosts)
4874 AMD 29000 embedded with COFF a29k-none-coff
4875 AMD 29000 embedded with a.out a29k-none-aout
4876 Ultracomputer remote kernel debug a29k-nyu-kern
4878 * New remote interfaces
4884 *** Changes in GDB-4.0:
4888 Wide output is wrapped at good places to make the output more readable.
4890 Gdb now supports cross-debugging from a host machine of one type to a
4891 target machine of another type. Communication with the target system
4892 is over serial lines. The ``target'' command handles connecting to the
4893 remote system; the ``load'' command will download a program into the
4894 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4895 also supports debugging of realtime processes running under VxWorks,
4896 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4897 stub on the target system.
4899 New CPUs supported include the AMD 29000 and Intel 960.
4901 GDB now reads object files and symbol tables via a ``binary file''
4902 library, which allows a single copy of GDB to debug programs of multiple
4903 object file types such as a.out and coff.
4905 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4906 refcard.dvi and refcard.ps are available to format it).
4909 * Control-Variable user interface simplified
4911 All variables that control the operation of the debugger can be set
4912 by the ``set'' command, and displayed by the ``show'' command.
4914 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4915 ``Show prompt'' produces the response:
4916 Gdb's prompt is new-gdb=>.
4918 What follows are the NEW set commands. The command ``help set'' will
4919 print a complete list of old and new set commands. ``help set FOO''
4920 will give a longer description of the variable FOO. ``show'' will show
4921 all of the variable descriptions and their current settings.
4923 confirm on/off: Enables warning questions for operations that are
4924 hard to recover from, e.g. rerunning the program while
4925 it is already running. Default is ON.
4927 editing on/off: Enables EMACS style command line editing
4928 of input. Previous lines can be recalled with
4929 control-P, the current line can be edited with control-B,
4930 you can search for commands with control-R, etc.
4933 history filename NAME: NAME is where the gdb command history
4934 will be stored. The default is .gdb_history,
4935 or the value of the environment variable
4938 history size N: The size, in commands, of the command history. The
4939 default is 256, or the value of the environment variable
4942 history save on/off: If this value is set to ON, the history file will
4943 be saved after exiting gdb. If set to OFF, the
4944 file will not be saved. The default is OFF.
4946 history expansion on/off: If this value is set to ON, then csh-like
4947 history expansion will be performed on
4948 command line input. The default is OFF.
4950 radix N: Sets the default radix for input and output. It can be set
4951 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4952 in the current radix, so "set radix 10" is always a no-op.
4954 height N: This integer value is the number of lines on a page. Default
4955 is 24, the current `stty rows'' setting, or the ``li#''
4956 setting from the termcap entry matching the environment
4959 width N: This integer value is the number of characters on a line.
4960 Default is 80, the current `stty cols'' setting, or the ``co#''
4961 setting from the termcap entry matching the environment
4964 Note: ``set screensize'' is obsolete. Use ``set height'' and
4965 ``set width'' instead.
4967 print address on/off: Print memory addresses in various command displays,
4968 such as stack traces and structure values. Gdb looks
4969 more ``symbolic'' if you turn this off; it looks more
4970 ``machine level'' with it on. Default is ON.
4972 print array on/off: Prettyprint arrays. New convenient format! Default
4975 print demangle on/off: Print C++ symbols in "source" form if on,
4978 print asm-demangle on/off: Same, for assembler level printouts
4981 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4984 * Support for Epoch Environment.
4986 The epoch environment is a version of Emacs v18 with windowing. One
4987 new command, ``inspect'', is identical to ``print'', except that if you
4988 are running in the epoch environment, the value is printed in its own
4992 * Support for Shared Libraries
4994 GDB can now debug programs and core files that use SunOS shared libraries.
4995 Symbols from a shared library cannot be referenced
4996 before the shared library has been linked with the program (this
4997 happens after you type ``run'' and before the function main() is entered).
4998 At any time after this linking (including when examining core files
4999 from dynamically linked programs), gdb reads the symbols from each
5000 shared library when you type the ``sharedlibrary'' command.
5001 It can be abbreviated ``share''.
5003 sharedlibrary REGEXP: Load shared object library symbols for files
5004 matching a unix regular expression. No argument
5005 indicates to load symbols for all shared libraries.
5007 info sharedlibrary: Status of loaded shared libraries.
5012 A watchpoint stops execution of a program whenever the value of an
5013 expression changes. Checking for this slows down execution
5014 tremendously whenever you are in the scope of the expression, but is
5015 quite useful for catching tough ``bit-spreader'' or pointer misuse
5016 problems. Some machines such as the 386 have hardware for doing this
5017 more quickly, and future versions of gdb will use this hardware.
5019 watch EXP: Set a watchpoint (breakpoint) for an expression.
5021 info watchpoints: Information about your watchpoints.
5023 delete N: Deletes watchpoint number N (same as breakpoints).
5024 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5025 enable N: Re-enables watchpoint number N (same as breakpoints).
5028 * C++ multiple inheritance
5030 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5033 * C++ exception handling
5035 Gdb now supports limited C++ exception handling. Besides the existing
5036 ability to breakpoint on an exception handler, gdb can breakpoint on
5037 the raising of an exception (before the stack is peeled back to the
5040 catch FOO: If there is a FOO exception handler in the dynamic scope,
5041 set a breakpoint to catch exceptions which may be raised there.
5042 Multiple exceptions (``catch foo bar baz'') may be caught.
5044 info catch: Lists all exceptions which may be caught in the
5045 current stack frame.
5048 * Minor command changes
5050 The command ``call func (arg, arg, ...)'' now acts like the print
5051 command, except it does not print or save a value if the function's result
5052 is void. This is similar to dbx usage.
5054 The ``up'' and ``down'' commands now always print the frame they end up
5055 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5056 frames without printing.
5058 * New directory command
5060 'dir' now adds directories to the FRONT of the source search path.
5061 The path starts off empty. Source files that contain debug information
5062 about the directory in which they were compiled can be found even
5063 with an empty path; Sun CC and GCC include this information. If GDB can't
5064 find your source file in the current directory, type "dir .".
5066 * Configuring GDB for compilation
5068 For normal use, type ``./configure host''. See README or gdb.texinfo
5071 GDB now handles cross debugging. If you are remotely debugging between
5072 two different machines, type ``./configure host -target=targ''.
5073 Host is the machine where GDB will run; targ is the machine
5074 where the program that you are debugging will run.