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".
135 ** "catch load" and "catch unload" can be used to stop when a shared
136 library is loaded or unloaded, respectively.
138 ** "enable count" can be used to auto-disable a breakpoint after
141 ** "info vtbl" can be used to show the virtual method tables for
142 C++ and Java objects.
144 ** "explore" and its sub commands "explore value" and "explore type"
145 can be used to reccursively explore values and types of
146 expressions. These commands are available only if GDB is
147 configured with '--with-python'.
149 ** "info auto-load" shows status of all kinds of auto-loaded files,
150 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
151 sequences of commands files, "info auto-load python-scripts"
152 shows status of auto-loading Python script files,
153 "info auto-load local-gdbinit" shows status of loading init file
154 (.gdbinit) from current directory and "info auto-load libthread-db" shows
155 status of inferior specific thread debugging shared library loading.
157 ** "info auto-load-scripts", "set auto-load-scripts on|off"
158 and "show auto-load-scripts" commands have been deprecated, use their
159 "info auto-load python-scripts", "set auto-load python-scripts on|off"
160 and "show auto-load python-scripts" counterparts instead.
162 ** "dprintf location,format,args..." creates a dynamic printf, which
163 is basically a breakpoint that does a printf and immediately
164 resumes your program's execution, so it is like a printf that you
165 can insert dynamically at runtime instead of at compiletime.
167 ** "set print symbol"
169 Controls whether GDB attempts to display the symbol, if any,
170 corresponding to addresses it prints. This defaults to "on", but
171 you can set it to "off" to restore GDB's previous behavior.
173 * Deprecated commands
175 ** For the Renesas Super-H architecture, the "regs" command has been
176 deprecated, and "info all-registers" should be used instead.
180 Renesas RL78 rl78-*-elf
181 HP OpenVMS ia64 ia64-hp-openvms*
183 * GDBserver supports evaluation of breakpoint conditions. When
184 support is advertised by GDBserver, GDB may be told to send the
185 breakpoint conditions in bytecode form to GDBserver. GDBserver
186 will only report the breakpoint trigger to GDB when its condition
192 show mips compression
193 Select the compressed ISA encoding used in functions that have no symbol
194 information available. The encoding can be set to either of:
197 and is updated automatically from ELF file flags if available.
199 set breakpoint condition-evaluation
200 show breakpoint condition-evaluation
201 Control whether breakpoint conditions are evaluated by GDB ("host") or by
202 GDBserver ("target"). Default option "auto" chooses the most efficient
204 This option can improve debugger efficiency depending on the speed of the
208 Disable auto-loading globally.
211 Show auto-loading setting of all kinds of auto-loaded files.
213 set auto-load gdb-scripts on|off
214 show auto-load gdb-scripts
215 Control auto-loading of GDB canned sequences of commands files.
217 set auto-load python-scripts on|off
218 show auto-load python-scripts
219 Control auto-loading of Python script files.
221 set auto-load local-gdbinit on|off
222 show auto-load local-gdbinit
223 Control loading of init file (.gdbinit) from current directory.
225 set auto-load libthread-db on|off
226 show auto-load libthread-db
227 Control auto-loading of inferior specific thread debugging shared library.
229 set auto-load scripts-directory <dir1>[:<dir2>...]
230 show auto-load scripts-directory
231 Set a list of directories from which to load auto-loaded scripts.
232 Automatically loaded Python scripts and GDB scripts are located in one
233 of the directories listed by this option.
234 The delimiter (':' above) may differ according to the host platform.
236 set auto-load safe-path <dir1>[:<dir2>...]
237 show auto-load safe-path
238 Set a list of directories from which it is safe to auto-load files.
239 The delimiter (':' above) may differ according to the host platform.
241 set debug auto-load on|off
243 Control display of debugging info for auto-loading the files above.
245 set dprintf-style gdb|call
247 Control the way in which a dynamic printf is performed; "gdb" requests
248 a GDB printf command, while "call" causes dprintf to call a function
251 set dprintf-function <expr>
252 show dprintf-function
253 set dprintf-channel <expr>
255 Set the function and optional first argument to the call when using
256 the "call" style of dynamic printf.
258 * New configure options
261 Configure default value for the 'set auto-load scripts-directory'
262 setting above. It defaults to '$debugdir:$datadir/auto-load',
263 $debugdir representing global debugging info directories (available
264 via 'show debug-file-directory') and $datadir representing GDB's data
265 directory (available via 'show data-directory').
267 --with-auto-load-safe-path
268 Configure default value for the 'set auto-load safe-path' setting
269 above. It defaults to the --with-auto-load-dir setting.
271 --without-auto-load-safe-path
272 Set 'set auto-load safe-path' to '/', effectively disabling this
277 z0/z1 conditional breakpoints extension
279 The z0/z1 breakpoint insertion packets have been extended to carry
280 a list of conditional expressions over to the remote stub depending on the
281 condition evaluation mode. The use of this extension can be controlled
282 via the "set remote conditional-breakpoints-packet" command.
286 Specify the signals which the remote stub may pass to the debugged
287 program without GDB involvement.
289 * New command line options
291 --init-command=FILE, -ix Like --command, -x but execute it
292 before loading inferior.
293 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
294 execute it before loading inferior.
296 *** Changes in GDB 7.4
298 * GDB now handles ambiguous linespecs more consistently; the existing
299 FILE:LINE support has been expanded to other types of linespecs. A
300 breakpoint will now be set on all matching locations in all
301 inferiors, and locations will be added or removed according to
304 * GDB now allows you to skip uninteresting functions and files when
305 stepping with the "skip function" and "skip file" commands.
307 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
308 and "show remote hardware-watchpoint-length-limit". These allows to
309 set or show the maximum length limit (in bytes) of a remote
310 target hardware watchpoint.
312 This allows e.g. to use "unlimited" hardware watchpoints with the
313 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
314 watchpoints are slower than real hardware watchpoints but are
315 significantly faster than gdb software watchpoints.
319 ** The register_pretty_printer function in module gdb.printing now takes
320 an optional `replace' argument. If True, the new printer replaces any
323 ** The "maint set python print-stack on|off" command has been
324 deprecated and will be deleted in GDB 7.5.
325 A new command: "set python print-stack none|full|message" has
326 replaced it. Additionally, the default for "print-stack" is
327 now "message", which just prints the error message without
330 ** A prompt substitution hook (prompt_hook) is now available to the
333 ** A new Python module, gdb.prompt has been added to the GDB Python
334 modules library. This module provides functionality for
335 escape sequences in prompts (used by set/show
336 extended-prompt). These escape sequences are replaced by their
339 ** Python commands and convenience-functions located in
340 'data-directory'/python/gdb/command and
341 'data-directory'/python/gdb/function are now automatically loaded
344 ** Blocks now provide four new attributes. global_block and
345 static_block will return the global and static blocks
346 respectively. is_static and is_global are boolean attributes
347 that indicate if the block is one of those two types.
349 ** Symbols now provide the "type" attribute, the type of the symbol.
351 ** The "gdb.breakpoint" function has been deprecated in favor of
354 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
355 of a function. This class is based on the "finish" command
356 available in the CLI.
358 ** Type objects for struct and union types now allow access to
359 the fields using standard Python dictionary (mapping) methods.
360 For example, "some_type['myfield']" now works, as does
363 ** A new event "gdb.new_objfile" has been added, triggered by loading a
366 ** A new function, "deep_items" has been added to the gdb.types
367 module in the GDB Python modules library. This function returns
368 an iterator over the fields of a struct or union type. Unlike
369 the standard Python "iteritems" method, it will recursively traverse
370 any anonymous fields.
374 ** "*stopped" events can report several new "reason"s, such as
377 ** Breakpoint changes are now notified using new async records, like
378 "=breakpoint-modified".
380 ** New command -ada-task-info.
382 * libthread-db-search-path now supports two special values: $sdir and $pdir.
383 $sdir specifies the default system locations of shared libraries.
384 $pdir specifies the directory where the libpthread used by the application
387 GDB no longer looks in $sdir and $pdir after it has searched the directories
388 mentioned in libthread-db-search-path. If you want to search those
389 directories, they must be specified in libthread-db-search-path.
390 The default value of libthread-db-search-path on GNU/Linux and Solaris
391 systems is now "$sdir:$pdir".
393 $pdir is not supported by gdbserver, it is currently ignored.
394 $sdir is supported by gdbserver.
396 * New configure option --with-iconv-bin.
397 When using the internationalization support like the one in the GNU C
398 library, GDB will invoke the "iconv" program to get a list of supported
399 character sets. If this program lives in a non-standard location, one can
400 use this option to specify where to find it.
402 * When natively debugging programs on PowerPC BookE processors running
403 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
404 watchpoints, which specify a mask in addition to an address to watch.
405 The mask specifies that some bits of an address (the bits which are
406 reset in the mask) should be ignored when matching the address accessed
407 by the inferior against the watchpoint address. See the "PowerPC Embedded"
408 section in the user manual for more details.
410 * The new option --once causes GDBserver to stop listening for connections once
411 the first connection is made. The listening port used by GDBserver will
412 become available after that.
414 * New commands "info macros" and "alias" have been added.
416 * New function parameters suffix @entry specifies value of function parameter
417 at the time the function got called. Entry values are available only since
423 "!" is now an alias of the "shell" command.
424 Note that no space is needed between "!" and SHELL COMMAND.
428 watch EXPRESSION mask MASK_VALUE
429 The watch command now supports the mask argument which allows creation
430 of masked watchpoints, if the current architecture supports this feature.
432 info auto-load-scripts [REGEXP]
433 This command was formerly named "maintenance print section-scripts".
434 It is now generally useful and is no longer a maintenance-only command.
436 info macro [-all] [--] MACRO
437 The info macro command has new options `-all' and `--'. The first for
438 printing all definitions of a macro. The second for explicitly specifying
439 the end of arguments and the beginning of the macro name in case the macro
440 name starts with a hyphen.
442 collect[/s] EXPRESSIONS
443 The tracepoint collect command now takes an optional modifier "/s"
444 that directs it to dereference pointer-to-character types and
445 collect the bytes of memory up to a zero byte. The behavior is
446 similar to what you see when you use the regular print command on a
447 string. An optional integer following the "/s" sets a bound on the
448 number of bytes that will be collected.
451 The trace start command now interprets any supplied arguments as a
452 note to be recorded with the trace run, with an effect similar to
453 setting the variable trace-notes.
456 The trace stop command now interprets any arguments as a note to be
457 mentioned along with the tstatus report that the trace was stopped
458 with a command. The effect is similar to setting the variable
461 * Tracepoints can now be enabled and disabled at any time after a trace
462 experiment has been started using the standard "enable" and "disable"
463 commands. It is now possible to start a trace experiment with no enabled
464 tracepoints; GDB will display a warning, but will allow the experiment to
465 begin, assuming that tracepoints will be enabled as needed while the trace
468 * Fast tracepoints on 32-bit x86-architectures can now be placed at
469 locations with 4-byte instructions, when they were previously
470 limited to locations with instructions of 5 bytes or longer.
474 set debug dwarf2-read
475 show debug dwarf2-read
476 Turns on or off display of debugging messages related to reading
477 DWARF debug info. The default is off.
479 set debug symtab-create
480 show debug symtab-create
481 Turns on or off display of debugging messages related to symbol table
482 creation. The default is off.
486 Set the GDB prompt, and allow escape sequences to be inserted to
487 display miscellaneous information (see 'help set extended-prompt'
488 for the list of sequences). This prompt (and any information
489 accessed through the escape sequences) is updated every time the
492 set print entry-values (both|compact|default|if-needed|no|only|preferred)
493 show print entry-values
494 Set printing of frame argument values at function entry. In some cases
495 GDB can determine the value of function argument which was passed by the
496 function caller, even if the value was modified inside the called function.
498 set debug entry-values
499 show debug entry-values
500 Control display of debugging info for determining frame argument values at
501 function entry and virtual tail call frames.
503 set basenames-may-differ
504 show basenames-may-differ
505 Set whether a source file may have multiple base names.
506 (A "base name" is the name of a file with the directory part removed.
507 Example: The base name of "/home/user/hello.c" is "hello.c".)
508 If set, GDB will canonicalize file names (e.g., expand symlinks)
509 before comparing them. Canonicalization is an expensive operation,
510 but it allows the same file be known by more than one base name.
511 If not set (the default), all source files are assumed to have just
512 one base name, and gdb will do file name comparisons more efficiently.
518 Set a user name and notes for the current and any future trace runs.
519 This is useful for long-running and/or disconnected traces, to
520 inform others (or yourself) as to who is running the trace, supply
521 contact information, or otherwise explain what is going on.
524 show trace-stop-notes
525 Set a note attached to the trace run, that is displayed when the
526 trace has been stopped by a tstop command. This is useful for
527 instance as an explanation, if you are stopping a trace run that was
528 started by someone else.
534 Dynamically enable a tracepoint in a started trace experiment.
538 Dynamically disable a tracepoint in a started trace experiment.
542 Set the user and notes of the trace run.
546 Query the current status of a tracepoint.
550 Query the minimum length of instruction at which a fast tracepoint may
553 * Dcache size (number of lines) and line-size are now runtime-configurable
554 via "set dcache line" and "set dcache line-size" commands.
558 Texas Instruments TMS320C6x tic6x-*-*
562 Renesas RL78 rl78-*-elf
564 *** Changes in GDB 7.3.1
566 * The build failure for NetBSD and OpenBSD targets have now been fixed.
568 *** Changes in GDB 7.3
570 * GDB has a new command: "thread find [REGEXP]".
571 It finds the thread id whose name, target id, or thread extra info
572 matches the given regular expression.
574 * The "catch syscall" command now works on mips*-linux* targets.
576 * The -data-disassemble MI command now supports modes 2 and 3 for
577 dumping the instruction opcodes.
579 * New command line options
581 -data-directory DIR Specify DIR as the "data-directory".
582 This is mostly for testing purposes.
584 * The "maint set python auto-load on|off" command has been renamed to
585 "set auto-load-scripts on|off".
587 * GDB has a new command: "set directories".
588 It is like the "dir" command except that it replaces the
589 source path list instead of augmenting it.
591 * GDB now understands thread names.
593 On GNU/Linux, "info threads" will display the thread name as set by
594 prctl or pthread_setname_np.
596 There is also a new command, "thread name", which can be used to
597 assign a name internally for GDB to display.
600 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
601 has been integrated into GDB.
605 ** The function gdb.Write now accepts an optional keyword 'stream'.
606 This keyword, when provided, will direct the output to either
607 stdout, stderr, or GDB's logging output.
609 ** Parameters can now be be sub-classed in Python, and in particular
610 you may implement the get_set_doc and get_show_doc functions.
611 This improves how Parameter set/show documentation is processed
612 and allows for more dynamic content.
614 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
615 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
616 have an is_valid method.
618 ** Breakpoints can now be sub-classed in Python, and in particular
619 you may implement a 'stop' function that is executed each time
620 the inferior reaches that breakpoint.
622 ** New function gdb.lookup_global_symbol looks up a global symbol.
624 ** GDB values in Python are now callable if the value represents a
625 function. For example, if 'some_value' represents a function that
626 takes two integer parameters and returns a value, you can call
627 that function like so:
629 result = some_value (10,20)
631 ** Module gdb.types has been added.
632 It contains a collection of utilities for working with gdb.Types objects:
633 get_basic_type, has_field, make_enum_dict.
635 ** Module gdb.printing has been added.
636 It contains utilities for writing and registering pretty-printers.
637 New classes: PrettyPrinter, SubPrettyPrinter,
638 RegexpCollectionPrettyPrinter.
639 New function: register_pretty_printer.
641 ** New commands "info pretty-printers", "enable pretty-printer" and
642 "disable pretty-printer" have been added.
644 ** gdb.parameter("directories") is now available.
646 ** New function gdb.newest_frame returns the newest frame in the
649 ** The gdb.InferiorThread class has a new "name" attribute. This
650 holds the thread's name.
652 ** Python Support for Inferior events.
653 Python scripts can add observers to be notified of events
654 occurring in the process being debugged.
655 The following events are currently supported:
656 - gdb.events.cont Continue event.
657 - gdb.events.exited Inferior exited event.
658 - gdb.events.stop Signal received, and Breakpoint hit events.
662 ** GDB now puts template parameters in scope when debugging in an
663 instantiation. For example, if you have:
665 template<int X> int func (void) { return X; }
667 then if you step into func<5>, "print X" will show "5". This
668 feature requires proper debuginfo support from the compiler; it
669 was added to GCC 4.5.
671 ** The motion commands "next", "finish", "until", and "advance" now
672 work better when exceptions are thrown. In particular, GDB will
673 no longer lose control of the inferior; instead, the GDB will
674 stop the inferior at the point at which the exception is caught.
675 This functionality requires a change in the exception handling
676 code that was introduced in GCC 4.5.
678 * GDB now follows GCC's rules on accessing volatile objects when
679 reading or writing target state during expression evaluation.
680 One notable difference to prior behavior is that "print x = 0"
681 no longer generates a read of x; the value of the assignment is
682 now always taken directly from the value being assigned.
684 * GDB now has some support for using labels in the program's source in
685 linespecs. For instance, you can use "advance label" to continue
686 execution to a label.
688 * GDB now has support for reading and writing a new .gdb_index
689 section. This section holds a fast index of DWARF debugging
690 information and can be used to greatly speed up GDB startup and
691 operation. See the documentation for `save gdb-index' for details.
693 * The "watch" command now accepts an optional "-location" argument.
694 When used, this causes GDB to watch the memory referred to by the
695 expression. Such a watchpoint is never deleted due to it going out
698 * GDB now supports thread debugging of core dumps on GNU/Linux.
700 GDB now activates thread debugging using the libthread_db library
701 when debugging GNU/Linux core dumps, similarly to when debugging
702 live processes. As a result, when debugging a core dump file, GDB
703 is now able to display pthread_t ids of threads. For example, "info
704 threads" shows the same output as when debugging the process when it
705 was live. In earlier releases, you'd see something like this:
708 * 1 LWP 6780 main () at main.c:10
710 While now you see this:
713 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
715 It is also now possible to inspect TLS variables when debugging core
718 When debugging a core dump generated on a machine other than the one
719 used to run GDB, you may need to point GDB at the correct
720 libthread_db library with the "set libthread-db-search-path"
721 command. See the user manual for more details on this command.
723 * When natively debugging programs on PowerPC BookE processors running
724 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
725 which stop execution of the inferior whenever it executes an instruction
726 at any address within the specified range. See the "PowerPC Embedded"
727 section in the user manual for more details.
729 * New features in the GDB remote stub, GDBserver
731 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
732 and i686 LynxOS (version 5.x).
734 ** GDBserver is now supported on Blackfin Linux.
736 * New native configurations
738 ia64 HP-UX ia64-*-hpux*
742 Analog Devices, Inc. Blackfin Processor bfin-*
744 * Ada task switching is now supported on sparc-elf targets when
745 debugging a program using the Ravenscar Profile. For more information,
746 see the "Tasking Support when using the Ravenscar Profile" section
747 in the GDB user manual.
749 * Guile support was removed.
751 * New features in the GNU simulator
753 ** The --map-info flag lists all known core mappings.
755 ** CFI flashes may be simulated via the "cfi" device.
757 *** Changes in GDB 7.2
759 * Shared library support for remote targets by default
761 When GDB is configured for a generic, non-OS specific target, like
762 for example, --target=arm-eabi or one of the many *-*-elf targets,
763 GDB now queries remote stubs for loaded shared libraries using the
764 `qXfer:libraries:read' packet. Previously, shared library support
765 was always disabled for such configurations.
769 ** Argument Dependent Lookup (ADL)
771 In C++ ADL lookup directs function search to the namespaces of its
772 arguments even if the namespace has not been imported.
782 Here the compiler will search for `foo' in the namespace of 'b'
783 and find A::foo. GDB now supports this. This construct is commonly
784 used in the Standard Template Library for operators.
786 ** Improved User Defined Operator Support
788 In addition to member operators, GDB now supports lookup of operators
789 defined in a namespace and imported with a `using' directive, operators
790 defined in the global scope, operators imported implicitly from an
791 anonymous namespace, and the ADL operators mentioned in the previous
793 GDB now also supports proper overload resolution for all the previously
794 mentioned flavors of operators.
796 ** static const class members
798 Printing of static const class members that are initialized in the
799 class definition has been fixed.
801 * Windows Thread Information Block access.
803 On Windows targets, GDB now supports displaying the Windows Thread
804 Information Block (TIB) structure. This structure is visible either
805 by using the new command `info w32 thread-information-block' or, by
806 dereferencing the new convenience variable named `$_tlb', a
807 thread-specific pointer to the TIB. This feature is also supported
808 when remote debugging using GDBserver.
812 Static tracepoints are calls in the user program into a tracing
813 library. One such library is a port of the LTTng kernel tracer to
814 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
815 When debugging with GDBserver, GDB now supports combining the GDB
816 tracepoint machinery with such libraries. For example: the user can
817 use GDB to probe a static tracepoint marker (a call from the user
818 program into the tracing library) with the new "strace" command (see
819 "New commands" below). This creates a "static tracepoint" in the
820 breakpoint list, that can be manipulated with the same feature set
821 as fast and regular tracepoints. E.g., collect registers, local and
822 global variables, collect trace state variables, and define
823 tracepoint conditions. In addition, the user can collect extra
824 static tracepoint marker specific data, by collecting the new
825 $_sdata internal variable. When analyzing the trace buffer, you can
826 inspect $_sdata like any other variable available to GDB. For more
827 information, see the "Tracepoints" chapter in GDB user manual. New
828 remote packets have been defined to support static tracepoints, see
829 the "New remote packets" section below.
831 * Better reconstruction of tracepoints after disconnected tracing
833 GDB will attempt to download the original source form of tracepoint
834 definitions when starting a trace run, and then will upload these
835 upon reconnection to the target, resulting in a more accurate
836 reconstruction of the tracepoints that are in use on the target.
840 You can now exercise direct control over the ways that GDB can
841 affect your program. For instance, you can disallow the setting of
842 breakpoints, so that the program can run continuously (assuming
843 non-stop mode). In addition, the "observer" variable is available
844 to switch all of the different controls; in observer mode, GDB
845 cannot affect the target's behavior at all, which is useful for
846 tasks like diagnosing live systems in the field.
848 * The new convenience variable $_thread holds the number of the
855 Return the address of the Windows Thread Information Block of a given thread.
859 In response to several of the tracepoint packets, the target may now
860 also respond with a number of intermediate `qRelocInsn' request
861 packets before the final result packet, to have GDB handle
862 relocating an instruction to execute at a different address. This
863 is particularly useful for stubs that support fast tracepoints. GDB
864 reports support for this feature in the qSupported packet.
868 List static tracepoint markers in the target program.
872 List static tracepoint markers at a given address in the target
875 qXfer:statictrace:read
877 Read the static trace data collected (by a `collect $_sdata'
878 tracepoint action). The remote stub reports support for this packet
879 to gdb's qSupported query.
883 Send the current settings of GDB's permission flags.
887 Send part of the source (textual) form of a tracepoint definition,
888 which includes location, conditional, and action list.
890 * The source command now accepts a -s option to force searching for the
891 script in the source search path even if the script name specifies
894 * New features in the GDB remote stub, GDBserver
896 - GDBserver now support tracepoints (including fast tracepoints, and
897 static tracepoints). The feature is currently supported by the
898 i386-linux and amd64-linux builds. See the "Tracepoints support
899 in gdbserver" section in the manual for more information.
901 GDBserver JIT compiles the tracepoint's conditional agent
902 expression bytecode into native code whenever possible for low
903 overhead dynamic tracepoints conditionals. For such tracepoints,
904 an expression that examines program state is evaluated when the
905 tracepoint is reached, in order to determine whether to capture
906 trace data. If the condition is simple and false, processing the
907 tracepoint finishes very quickly and no data is gathered.
909 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
910 for static tracepoints support.
912 - GDBserver now supports x86_64 Windows 64-bit debugging.
914 * GDB now sends xmlRegisters= in qSupported packet to indicate that
915 it understands register description.
917 * The --batch flag now disables pagination and queries.
919 * X86 general purpose registers
921 GDB now supports reading/writing byte, word and double-word x86
922 general purpose registers directly. This means you can use, say,
923 $ah or $ax to refer, respectively, to the byte register AH and
924 16-bit word register AX that are actually portions of the 32-bit
925 register EAX or 64-bit register RAX.
927 * The `commands' command now accepts a range of breakpoints to modify.
928 A plain `commands' following a command that creates multiple
929 breakpoints affects all the breakpoints set by that command. This
930 applies to breakpoints set by `rbreak', and also applies when a
931 single `break' command creates multiple breakpoints (e.g.,
932 breakpoints on overloaded c++ functions).
934 * The `rbreak' command now accepts a filename specification as part of
935 its argument, limiting the functions selected by the regex to those
936 in the specified file.
938 * Support for remote debugging Windows and SymbianOS shared libraries
939 from Unix hosts has been improved. Non Windows GDB builds now can
940 understand target reported file names that follow MS-DOS based file
941 system semantics, such as file names that include drive letters and
942 use the backslash character as directory separator. This makes it
943 possible to transparently use the "set sysroot" and "set
944 solib-search-path" on Unix hosts to point as host copies of the
945 target's shared libraries. See the new command "set
946 target-file-system-kind" described below, and the "Commands to
947 specify files" section in the user manual for more information.
951 eval template, expressions...
952 Convert the values of one or more expressions under the control
953 of the string template to a command line, and call it.
955 set target-file-system-kind unix|dos-based|auto
956 show target-file-system-kind
957 Set or show the assumed file system kind for target reported file
960 save breakpoints <filename>
961 Save all current breakpoint definitions to a file suitable for use
962 in a later debugging session. To read the saved breakpoint
963 definitions, use the `source' command.
965 `save tracepoints' is a new alias for `save-tracepoints'. The latter
968 info static-tracepoint-markers
969 Display information about static tracepoint markers in the target.
971 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
972 Define a static tracepoint by probing a marker at the given
973 function, line, address, or marker ID.
977 Enable and disable observer mode.
979 set may-write-registers on|off
980 set may-write-memory on|off
981 set may-insert-breakpoints on|off
982 set may-insert-tracepoints on|off
983 set may-insert-fast-tracepoints on|off
984 set may-interrupt on|off
985 Set individual permissions for GDB effects on the target. Note that
986 some of these settings can have undesirable or surprising
987 consequences, particularly when changed in the middle of a session.
988 For instance, disabling the writing of memory can prevent
989 breakpoints from being inserted, cause single-stepping to fail, or
990 even crash your program, if you disable after breakpoints have been
991 inserted. However, GDB should not crash.
993 set record memory-query on|off
994 show record memory-query
995 Control whether to stop the inferior if memory changes caused
996 by an instruction cannot be recorded.
1001 The disassemble command now supports "start,+length" form of two arguments.
1005 ** GDB now provides a new directory location, called the python directory,
1006 where Python scripts written for GDB can be installed. The location
1007 of that directory is <data-directory>/python, where <data-directory>
1008 is the GDB data directory. For more details, see section `Scripting
1009 GDB using Python' in the manual.
1011 ** The GDB Python API now has access to breakpoints, symbols, symbol
1012 tables, program spaces, inferiors, threads and frame's code blocks.
1013 Additionally, GDB Parameters can now be created from the API, and
1014 manipulated via set/show in the CLI.
1016 ** New functions gdb.target_charset, gdb.target_wide_charset,
1017 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1019 ** New exception gdb.GdbError.
1021 ** Pretty-printers are now also looked up in the current program space.
1023 ** Pretty-printers can now be individually enabled and disabled.
1025 ** GDB now looks for names of Python scripts to auto-load in a
1026 special section named `.debug_gdb_scripts', in addition to looking
1027 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1029 * Tracepoint actions were unified with breakpoint commands. In particular,
1030 there are no longer differences in "info break" output for breakpoints and
1031 tracepoints and the "commands" command can be used for both tracepoints and
1032 regular breakpoints.
1036 ARM Symbian arm*-*-symbianelf*
1038 * D language support.
1039 GDB now supports debugging programs written in the D programming
1042 * GDB now supports the extended ptrace interface for PowerPC which is
1043 available since Linux kernel version 2.6.34. This automatically enables
1044 any hardware breakpoints and additional hardware watchpoints available in
1045 the processor. The old ptrace interface exposes just one hardware
1046 watchpoint and no hardware breakpoints.
1048 * GDB is now able to use the Data Value Compare (DVC) register available on
1049 embedded PowerPC processors to implement in hardware simple watchpoint
1050 conditions of the form:
1052 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1054 This works in native GDB running on Linux kernels with the extended ptrace
1055 interface mentioned above.
1057 *** Changes in GDB 7.1
1061 ** Namespace Support
1063 GDB now supports importing of namespaces in C++. This enables the
1064 user to inspect variables from imported namespaces. Support for
1065 namepace aliasing has also been added. So, if a namespace is
1066 aliased in the current scope (e.g. namepace C=A; ) the user can
1067 print variables using the alias (e.g. (gdb) print C::x).
1071 All known bugs relating to the printing of virtual base class were
1072 fixed. It is now possible to call overloaded static methods using a
1077 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1078 and reinterpret_cast<> are now handled by the C++ expression parser.
1082 Xilinx MicroBlaze microblaze-*-*
1087 Xilinx MicroBlaze microblaze
1090 * Multi-program debugging.
1092 GDB now has support for multi-program (a.k.a. multi-executable or
1093 multi-exec) debugging. This allows for debugging multiple inferiors
1094 simultaneously each running a different program under the same GDB
1095 session. See "Debugging Multiple Inferiors and Programs" in the
1096 manual for more information. This implied some user visible changes
1097 in the multi-inferior support. For example, "info inferiors" now
1098 lists inferiors that are not running yet or that have exited
1099 already. See also "New commands" and "New options" below.
1101 * New tracing features
1103 GDB's tracepoint facility now includes several new features:
1105 ** Trace state variables
1107 GDB tracepoints now include support for trace state variables, which
1108 are variables managed by the target agent during a tracing
1109 experiment. They are useful for tracepoints that trigger each
1110 other, so for instance one tracepoint can count hits in a variable,
1111 and then a second tracepoint has a condition that is true when the
1112 count reaches a particular value. Trace state variables share the
1113 $-syntax of GDB convenience variables, and can appear in both
1114 tracepoint actions and condition expressions. Use the "tvariable"
1115 command to create, and "info tvariables" to view; see "Trace State
1116 Variables" in the manual for more detail.
1120 GDB now includes an option for defining fast tracepoints, which
1121 targets may implement more efficiently, such as by installing a jump
1122 into the target agent rather than a trap instruction. The resulting
1123 speedup can be by two orders of magnitude or more, although the
1124 tradeoff is that some program locations on some target architectures
1125 might not allow fast tracepoint installation, for instance if the
1126 instruction to be replaced is shorter than the jump. To request a
1127 fast tracepoint, use the "ftrace" command, with syntax identical to
1128 the regular trace command.
1130 ** Disconnected tracing
1132 It is now possible to detach GDB from the target while it is running
1133 a trace experiment, then reconnect later to see how the experiment
1134 is going. In addition, a new variable disconnected-tracing lets you
1135 tell the target agent whether to continue running a trace if the
1136 connection is lost unexpectedly.
1140 GDB now has the ability to save the trace buffer into a file, and
1141 then use that file as a target, similarly to you can do with
1142 corefiles. You can select trace frames, print data that was
1143 collected in them, and use tstatus to display the state of the
1144 tracing run at the moment that it was saved. To create a trace
1145 file, use "tsave <filename>", and to use it, do "target tfile
1148 ** Circular trace buffer
1150 You can ask the target agent to handle the trace buffer as a
1151 circular buffer, discarding the oldest trace frames to make room for
1152 newer ones, by setting circular-trace-buffer to on. This feature may
1153 not be available for all target agents.
1158 The disassemble command, when invoked with two arguments, now requires
1159 the arguments to be comma-separated.
1162 The info variables command now displays variable definitions. Files
1163 which only declare a variable are not shown.
1166 The source command is now capable of sourcing Python scripts.
1167 This feature is dependent on the debugger being build with Python
1170 Related to this enhancement is also the introduction of a new command
1171 "set script-extension" (see below).
1173 * New commands (for set/show, see "New options" below)
1175 record save [<FILENAME>]
1176 Save a file (in core file format) containing the process record
1177 execution log for replay debugging at a later time.
1179 record restore <FILENAME>
1180 Restore the process record execution log that was saved at an
1181 earlier time, for replay debugging.
1183 add-inferior [-copies <N>] [-exec <FILENAME>]
1186 clone-inferior [-copies <N>] [ID]
1187 Make a new inferior ready to execute the same program another
1188 inferior has loaded.
1193 maint info program-spaces
1194 List the program spaces loaded into GDB.
1196 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1197 show remote interrupt-sequence
1198 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1199 as the sequence to the remote target in order to interrupt the execution.
1200 Ctrl-C is a default. Some system prefers BREAK which is high level of
1201 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1202 Magic SysRq g. It is BREAK signal and character 'g'.
1204 set remote interrupt-on-connect [on | off]
1205 show remote interrupt-on-connect
1206 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1207 remote target when gdb connects to it. This is needed when you debug
1210 set remotebreak [on | off]
1212 Deprecated. Use "set/show remote interrupt-sequence" instead.
1214 tvariable $NAME [ = EXP ]
1215 Create or modify a trace state variable.
1218 List trace state variables and their values.
1220 delete tvariable $NAME ...
1221 Delete one or more trace state variables.
1224 Evaluate the given expressions without collecting anything into the
1225 trace buffer. (Valid in tracepoint actions only.)
1227 ftrace FN / FILE:LINE / *ADDR
1228 Define a fast tracepoint at the given function, line, or address.
1230 * New expression syntax
1232 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1233 GDB now parses 0b101010 identically with 42.
1237 set follow-exec-mode new|same
1238 show follow-exec-mode
1239 Control whether GDB reuses the same inferior across an exec call or
1240 creates a new one. This is useful to be able to restart the old
1241 executable after the inferior having done an exec call.
1243 set default-collect EXPR, ...
1244 show default-collect
1245 Define a list of expressions to be collected at each tracepoint.
1246 This is a useful way to ensure essential items are not overlooked,
1247 such as registers or a critical global variable.
1249 set disconnected-tracing
1250 show disconnected-tracing
1251 If set to 1, the target is instructed to continue tracing if it
1252 loses its connection to GDB. If 0, the target is to stop tracing
1255 set circular-trace-buffer
1256 show circular-trace-buffer
1257 If set to on, the target is instructed to use a circular trace buffer
1258 and discard the oldest trace frames instead of stopping the trace due
1259 to a full trace buffer. If set to off, the trace stops when the buffer
1260 fills up. Some targets may not support this.
1262 set script-extension off|soft|strict
1263 show script-extension
1264 If set to "off", the debugger does not perform any script language
1265 recognition, and all sourced files are assumed to be GDB scripts.
1266 If set to "soft" (the default), files are sourced according to
1267 filename extension, falling back to GDB scripts if the first
1269 If set to "strict", files are sourced according to filename extension.
1271 set ada trust-PAD-over-XVS on|off
1272 show ada trust-PAD-over-XVS
1273 If off, activate a workaround against a bug in the debugging information
1274 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1275 the GCC sources for more information about the GNAT encoding and
1276 PAD types in particular). It is always safe to set this option to
1277 off, but this introduces a slight performance penalty. The default
1280 * Python API Improvements
1282 ** GDB provides the new class gdb.LazyString. This is useful in
1283 some pretty-printing cases. The new method gdb.Value.lazy_string
1284 provides a simple way to create objects of this type.
1286 ** The fields returned by gdb.Type.fields now have an
1287 `is_base_class' attribute.
1289 ** The new method gdb.Type.range returns the range of an array type.
1291 ** The new method gdb.parse_and_eval can be used to parse and
1292 evaluate an expression.
1294 * New remote packets
1297 Define a trace state variable.
1300 Get the current value of a trace state variable.
1303 Set desired tracing behavior upon disconnection.
1306 Set the trace buffer to be linear or circular.
1309 Get data about the tracepoints currently in use.
1313 Process record now works correctly with hardware watchpoints.
1315 Multiple bug fixes have been made to the mips-irix port, making it
1316 much more reliable. In particular:
1317 - Debugging threaded applications is now possible again. Previously,
1318 GDB would hang while starting the program, or while waiting for
1319 the program to stop at a breakpoint.
1320 - Attaching to a running process no longer hangs.
1321 - An error occurring while loading a core file has been fixed.
1322 - Changing the value of the PC register now works again. This fixes
1323 problems observed when using the "jump" command, or when calling
1324 a function from GDB, or even when assigning a new value to $pc.
1325 - With the "finish" and "return" commands, the return value for functions
1326 returning a small array is now correctly printed.
1327 - It is now possible to break on shared library code which gets executed
1328 during a shared library init phase (code executed while executing
1329 their .init section). Previously, the breakpoint would have no effect.
1330 - GDB is now able to backtrace through the signal handler for
1331 non-threaded programs.
1333 PIE (Position Independent Executable) programs debugging is now supported.
1334 This includes debugging execution of PIC (Position Independent Code) shared
1335 libraries although for that, it should be possible to run such libraries as an
1338 *** Changes in GDB 7.0
1340 * GDB now has an interface for JIT compilation. Applications that
1341 dynamically generate code can create symbol files in memory and register
1342 them with GDB. For users, the feature should work transparently, and
1343 for JIT developers, the interface is documented in the GDB manual in the
1344 "JIT Compilation Interface" chapter.
1346 * Tracepoints may now be conditional. The syntax is as for
1347 breakpoints; either an "if" clause appended to the "trace" command,
1348 or the "condition" command is available. GDB sends the condition to
1349 the target for evaluation using the same bytecode format as is used
1350 for tracepoint actions.
1352 * The disassemble command now supports: an optional /r modifier, print the
1353 raw instructions in hex as well as in symbolic form, and an optional /m
1354 modifier to print mixed source+assembly.
1356 * Process record and replay
1358 In a architecture environment that supports ``process record and
1359 replay'', ``process record and replay'' target can record a log of
1360 the process execution, and replay it with both forward and reverse
1363 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1364 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1365 set execution-direction {forward|reverse}, for targets that support
1368 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1369 feature is available with a native GDB running on kernel version
1372 * GDB now has support for multi-byte and wide character sets on the
1373 target. Strings whose character type is wchar_t, char16_t, or
1374 char32_t are now correctly printed. GDB supports wide- and unicode-
1375 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1376 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1377 `printf'. This feature requires iconv to work properly; if your
1378 system does not have a working iconv, GDB can use GNU libiconv. See
1379 the installation instructions for more information.
1381 * GDB now supports automatic retrieval of shared library files from
1382 remote targets. To use this feature, specify a system root that begins
1383 with the `remote:' prefix, either via the `set sysroot' command or via
1384 the `--with-sysroot' configure-time option.
1386 * "info sharedlibrary" now takes an optional regex of libraries to show,
1387 and it now reports if a shared library has no debugging information.
1389 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1390 now complete on file names.
1392 * When completing in expressions, gdb will attempt to limit
1393 completions to allowable structure or union fields, where appropriate.
1394 For instance, consider:
1396 # struct example { int f1; double f2; };
1397 # struct example variable;
1400 If the user types TAB at the end of this command line, the available
1401 completions will be "f1" and "f2".
1403 * Inlined functions are now supported. They show up in backtraces, and
1404 the "step", "next", and "finish" commands handle them automatically.
1406 * GDB now supports the token-splicing (##) and stringification (#)
1407 operators when expanding macros. It also supports variable-arity
1410 * GDB now supports inspecting extra signal information, exported by
1411 the new $_siginfo convenience variable. The feature is currently
1412 implemented on linux ARM, i386 and amd64.
1414 * GDB can now display the VFP floating point registers and NEON vector
1415 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1416 can provide these registers (requires Linux 2.6.30 or later). Remote
1417 and simulator targets may also provide them.
1419 * New remote packets
1422 Search memory for a sequence of bytes.
1425 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1426 operation over reliable transport links. Use of this packet is
1427 controlled by the `set remote noack-packet' command.
1430 Kill the process with the specified process ID. Use this in preference
1431 to `k' when multiprocess protocol extensions are supported.
1434 Obtains additional operating system information
1438 Read or write additional signal information.
1440 * Removed remote protocol undocumented extension
1442 An undocumented extension to the remote protocol's `S' stop reply
1443 packet that permited the stub to pass a process id was removed.
1444 Remote servers should use the `T' stop reply packet instead.
1446 * GDB now supports multiple function calling conventions according to the
1447 DWARF-2 DW_AT_calling_convention function attribute.
1449 * The SH target utilizes the aforementioned change to distinguish between gcc
1450 and Renesas calling convention. It also adds the new CLI commands
1451 `set/show sh calling-convention'.
1453 * GDB can now read compressed debug sections, as produced by GNU gold
1454 with the --compress-debug-sections=zlib flag.
1456 * 64-bit core files are now supported on AIX.
1458 * Thread switching is now supported on Tru64.
1460 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1461 which will be allocated using malloc later in program execution.
1463 * The qXfer:libraries:read remote procotol packet now allows passing a
1464 list of section offsets.
1466 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1467 conditions handling signals delivered during attach or thread creation
1468 have also been fixed.
1470 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1471 From the user's standpoint, all unqualified instances of True and False
1472 are treated as the standard definitions, regardless of context.
1474 * GDB now parses C++ symbol and type names more flexibly. For
1477 template<typename T> class C { };
1480 GDB will now correctly handle all of:
1482 ptype C<char const *>
1483 ptype C<char const*>
1484 ptype C<const char *>
1485 ptype C<const char*>
1487 * New features in the GDB remote stub, gdbserver
1489 - The "--wrapper" command-line argument tells gdbserver to use a
1490 wrapper program to launch programs for debugging.
1492 - On PowerPC and S/390 targets, it is now possible to use a single
1493 gdbserver executable to debug both 32-bit and 64-bit programs.
1494 (This requires gdbserver itself to be built as a 64-bit executable.)
1496 - gdbserver uses the new noack protocol mode for TCP connections to
1497 reduce communications latency, if also supported and enabled in GDB.
1499 - Support for the sparc64-linux-gnu target is now included in
1502 - The amd64-linux build of gdbserver now supports debugging both
1503 32-bit and 64-bit programs.
1505 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1506 now support hardware watchpoints, and will use them automatically
1511 GDB now has support for scripting using Python. Whether this is
1512 available is determined at configure time.
1514 New GDB commands can now be written in Python.
1516 * Ada tasking support
1518 Ada tasks can now be inspected in GDB. The following commands have
1522 Print the list of Ada tasks.
1524 Print detailed information about task number N.
1526 Print the task number of the current task.
1528 Switch the context of debugging to task number N.
1530 * Support for user-defined prefixed commands. The "define" command can
1531 add new commands to existing prefixes, e.g. "target".
1533 * Multi-inferior, multi-process debugging.
1535 GDB now has generalized support for multi-inferior debugging. See
1536 "Debugging Multiple Inferiors" in the manual for more information.
1537 Although availability still depends on target support, the command
1538 set is more uniform now. The GNU/Linux specific multi-forks support
1539 has been migrated to this new framework. This implied some user
1540 visible changes; see "New commands" and also "Removed commands"
1543 * Target descriptions can now describe the target OS ABI. See the
1544 "Target Description Format" section in the user manual for more
1547 * Target descriptions can now describe "compatible" architectures
1548 to indicate that the target can execute applications for a different
1549 architecture in addition to those for the main target architecture.
1550 See the "Target Description Format" section in the user manual for
1553 * Multi-architecture debugging.
1555 GDB now includes general supports for debugging applications on
1556 hybrid systems that use more than one single processor architecture
1557 at the same time. Each such hybrid architecture still requires
1558 specific support to be added. The only hybrid architecture supported
1559 in this version of GDB is the Cell Broadband Engine.
1561 * GDB now supports integrated debugging of Cell/B.E. applications that
1562 use both the PPU and SPU architectures. To enable support for hybrid
1563 Cell/B.E. debugging, you need to configure GDB to support both the
1564 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1565 --enable-targets configure option.
1567 * Non-stop mode debugging.
1569 For some targets, GDB now supports an optional mode of operation in
1570 which you can examine stopped threads while other threads continue
1571 to execute freely. This is referred to as non-stop mode, with the
1572 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1573 section in the user manual for more information.
1575 To be able to support remote non-stop debugging, a remote stub needs
1576 to implement the non-stop mode remote protocol extensions, as
1577 described in the "Remote Non-Stop" section of the user manual. The
1578 GDB remote stub, gdbserver, has been adjusted to support these
1579 extensions on linux targets.
1581 * New commands (for set/show, see "New options" below)
1583 catch syscall [NAME(S) | NUMBER(S)]
1584 Catch system calls. Arguments, which should be names of system
1585 calls or their numbers, mean catch only those syscalls. Without
1586 arguments, every syscall will be caught. When the inferior issues
1587 any of the specified syscalls, GDB will stop and announce the system
1588 call, both when it is called and when its call returns. This
1589 feature is currently available with a native GDB running on the
1590 Linux Kernel, under the following architectures: x86, x86_64,
1591 PowerPC and PowerPC64.
1593 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1595 Search memory for a sequence of bytes.
1597 maint set python print-stack
1598 maint show python print-stack
1599 Show a stack trace when an error is encountered in a Python script.
1602 Invoke CODE by passing it to the Python interpreter.
1607 These allow macros to be defined, undefined, and listed
1611 Show operating system information about processes.
1614 List the inferiors currently under GDB's control.
1617 Switch focus to inferior number NUM.
1620 Detach from inferior number NUM.
1623 Kill inferior number NUM.
1627 set spu stop-on-load
1628 show spu stop-on-load
1629 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1631 set spu auto-flush-cache
1632 show spu auto-flush-cache
1633 Control whether to automatically flush the software-managed cache
1634 during Cell/B.E. debugging.
1636 set sh calling-convention
1637 show sh calling-convention
1638 Control the calling convention used when calling SH target functions.
1641 show debug timestamp
1642 Control display of timestamps with GDB debugging output.
1644 set disassemble-next-line
1645 show disassemble-next-line
1646 Control display of disassembled source lines or instructions when
1649 set remote noack-packet
1650 show remote noack-packet
1651 Set/show the use of remote protocol QStartNoAckMode packet. See above
1652 under "New remote packets."
1654 set remote query-attached-packet
1655 show remote query-attached-packet
1656 Control use of remote protocol `qAttached' (query-attached) packet.
1658 set remote read-siginfo-object
1659 show remote read-siginfo-object
1660 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1663 set remote write-siginfo-object
1664 show remote write-siginfo-object
1665 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1668 set remote reverse-continue
1669 show remote reverse-continue
1670 Control use of remote protocol 'bc' (reverse-continue) packet.
1672 set remote reverse-step
1673 show remote reverse-step
1674 Control use of remote protocol 'bs' (reverse-step) packet.
1676 set displaced-stepping
1677 show displaced-stepping
1678 Control displaced stepping mode. Displaced stepping is a way to
1679 single-step over breakpoints without removing them from the debuggee.
1680 Also known as "out-of-line single-stepping".
1683 show debug displaced
1684 Control display of debugging info for displaced stepping.
1686 maint set internal-error
1687 maint show internal-error
1688 Control what GDB does when an internal error is detected.
1690 maint set internal-warning
1691 maint show internal-warning
1692 Control what GDB does when an internal warning is detected.
1697 Use a wrapper program to launch programs for debugging.
1699 set multiple-symbols (all|ask|cancel)
1700 show multiple-symbols
1701 The value of this variable can be changed to adjust the debugger behavior
1702 when an expression or a breakpoint location contains an ambiguous symbol
1703 name (an overloaded function name, for instance).
1705 set breakpoint always-inserted
1706 show breakpoint always-inserted
1707 Keep breakpoints always inserted in the target, as opposed to inserting
1708 them when resuming the target, and removing them when the target stops.
1709 This option can improve debugger performance on slow remote targets.
1711 set arm fallback-mode (arm|thumb|auto)
1712 show arm fallback-mode
1713 set arm force-mode (arm|thumb|auto)
1715 These commands control how ARM GDB determines whether instructions
1716 are ARM or Thumb. The default for both settings is auto, which uses
1717 the current CPSR value for instructions without symbols; previous
1718 versions of GDB behaved as if "set arm fallback-mode arm".
1720 set disable-randomization
1721 show disable-randomization
1722 Standalone programs run with the virtual address space randomization enabled
1723 by default on some platforms. This option keeps the addresses stable across
1724 multiple debugging sessions.
1728 Control whether other threads are stopped or not when some thread hits
1733 Requests that asynchronous execution is enabled in the target, if available.
1734 In this case, it's possible to resume target in the background, and interact
1735 with GDB while the target is running. "show target-async" displays the
1736 current state of asynchronous execution of the target.
1738 set target-wide-charset
1739 show target-wide-charset
1740 The target-wide-charset is the name of the character set that GDB
1741 uses when printing characters whose type is wchar_t.
1743 set tcp auto-retry (on|off)
1745 set tcp connect-timeout
1746 show tcp connect-timeout
1747 These commands allow GDB to retry failed TCP connections to a remote stub
1748 with a specified timeout period; this is useful if the stub is launched
1749 in parallel with GDB but may not be ready to accept connections immediately.
1751 set libthread-db-search-path
1752 show libthread-db-search-path
1753 Control list of directories which GDB will search for appropriate
1756 set schedule-multiple (on|off)
1757 show schedule-multiple
1758 Allow GDB to resume all threads of all processes or only threads of
1759 the current process.
1763 Use more aggressive caching for accesses to the stack. This improves
1764 performance of remote debugging (particularly backtraces) without
1765 affecting correctness.
1767 set interactive-mode (on|off|auto)
1768 show interactive-mode
1769 Control whether GDB runs in interactive mode (on) or not (off).
1770 When in interactive mode, GDB waits for the user to answer all
1771 queries. Otherwise, GDB does not wait and assumes the default
1772 answer. When set to auto (the default), GDB determines which
1773 mode to use based on the stdin settings.
1778 For program forks, this is replaced by the new more generic `info
1779 inferiors' command. To list checkpoints, you can still use the
1780 `info checkpoints' command, which was an alias for the `info forks'
1784 Replaced by the new `inferior' command. To switch between
1785 checkpoints, you can still use the `restart' command, which was an
1786 alias for the `fork' command.
1789 This is removed, since some targets don't have a notion of
1790 processes. To switch between processes, you can still use the
1791 `inferior' command using GDB's own inferior number.
1794 For program forks, this is replaced by the new more generic `kill
1795 inferior' command. To delete a checkpoint, you can still use the
1796 `delete checkpoint' command, which was an alias for the `delete
1800 For program forks, this is replaced by the new more generic `detach
1801 inferior' command. To detach a checkpoint, you can still use the
1802 `detach checkpoint' command, which was an alias for the `detach
1805 * New native configurations
1807 x86/x86_64 Darwin i[34567]86-*-darwin*
1809 x86_64 MinGW x86_64-*-mingw*
1813 Lattice Mico32 lm32-*
1814 x86 DICOS i[34567]86-*-dicos*
1815 x86_64 DICOS x86_64-*-dicos*
1818 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1819 (mingw32ce) debugging.
1825 These commands were actually not implemented on any target.
1827 *** Changes in GDB 6.8
1829 * New native configurations
1831 NetBSD/hppa hppa*-*netbsd*
1832 Xtensa GNU/Linux xtensa*-*-linux*
1836 NetBSD/hppa hppa*-*-netbsd*
1837 Xtensa GNU/Lunux xtensa*-*-linux*
1839 * Change in command line behavior -- corefiles vs. process ids.
1841 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1842 attaching to process NUMBER fails, GDB no longer attempts to open a
1843 core file named NUMBER. Attaching to a program using the -c option
1844 is no longer supported. Instead, use the '-p' or '--pid' options.
1846 * GDB can now be built as a native debugger for debugging Windows x86
1847 (mingw32) Portable Executable (PE) programs.
1849 * Pending breakpoints no longer change their number when their address
1852 * GDB now supports breakpoints with multiple locations,
1853 including breakpoints on C++ constructors, inside C++ templates,
1854 and in inlined functions.
1856 * GDB's ability to debug optimized code has been improved. GDB more
1857 accurately identifies function bodies and lexical blocks that occupy
1858 more than one contiguous range of addresses.
1860 * Target descriptions can now describe registers for PowerPC.
1862 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1863 registers on PowerPC targets.
1865 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1866 targets even when the libthread_db library is not available.
1868 * The GDB remote stub, gdbserver, now supports the new file transfer
1869 commands (remote put, remote get, and remote delete).
1871 * The GDB remote stub, gdbserver, now supports run and attach in
1872 extended-remote mode.
1874 * hppa*64*-*-hpux11* target broken
1875 The debugger is unable to start a program and fails with the following
1876 error: "Error trying to get information about dynamic linker".
1877 The gdb-6.7 release is also affected.
1879 * GDB now supports the --enable-targets= configure option to allow
1880 building a single GDB executable that supports multiple remote
1881 target architectures.
1883 * GDB now supports debugging C and C++ programs which use the
1884 Decimal Floating Point extension. In addition, the PowerPC target
1885 now has a set of pseudo-registers to inspect decimal float values
1886 stored in two consecutive float registers.
1888 * The -break-insert MI command can optionally create pending
1891 * Improved support for debugging Ada
1892 Many improvements to the Ada language support have been made. These
1894 - Better support for Ada2005 interface types
1895 - Improved handling of arrays and slices in general
1896 - Better support for Taft-amendment types
1897 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1899 - Improved command completion in Ada
1902 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1907 set print frame-arguments (all|scalars|none)
1908 show print frame-arguments
1909 The value of this variable can be changed to control which argument
1910 values should be printed by the debugger when displaying a frame.
1915 Transfer files to and from a remote target, and delete remote files.
1922 Transfer files to and from a remote target, and delete remote files.
1924 * New remote packets
1931 Open, close, read, write, and delete files on the remote system.
1934 Attach to an existing process on the remote system, in extended-remote
1938 Run a new process on the remote system, in extended-remote mode.
1940 *** Changes in GDB 6.7
1942 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1943 bfd, libiberty and opcodes, as revealed by static analysis donated by
1944 Coverity, Inc. (http://scan.coverity.com).
1946 * When looking up multiply-defined global symbols, GDB will now prefer the
1947 symbol definition in the current shared library if it was built using the
1948 -Bsymbolic linker option.
1950 * When the Text User Interface (TUI) is not configured, GDB will now
1951 recognize the -tui command-line option and print a message that the TUI
1954 * The GDB remote stub, gdbserver, now has lower overhead for high
1955 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1957 * GDB for MIPS targets now autodetects whether a remote target provides
1958 32-bit or 64-bit register values.
1960 * Support for C++ member pointers has been improved.
1962 * GDB now understands XML target descriptions, which specify the
1963 target's overall architecture. GDB can read a description from
1964 a local file or over the remote serial protocol.
1966 * Vectors of single-byte data use a new integer type which is not
1967 automatically displayed as character or string data.
1969 * The /s format now works with the print command. It displays
1970 arrays of single-byte integers and pointers to single-byte integers
1973 * Target descriptions can now describe target-specific registers,
1974 for architectures which have implemented the support (currently
1975 only ARM, M68K, and MIPS).
1977 * GDB and the GDB remote stub, gdbserver, now support the XScale
1980 * The GDB remote stub, gdbserver, has been updated to support
1981 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1982 has been rewritten to use the standard GDB remote protocol.
1984 * GDB can now step into C++ functions which are called through thunks.
1986 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1988 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1989 layout. It also supports a TextSeg= and DataSeg= response when only
1990 segment base addresses (rather than offsets) are available.
1992 * The /i format now outputs any trailing branch delay slot instructions
1993 immediately following the last instruction within the count specified.
1995 * The GDB remote protocol "T" stop reply packet now supports a
1996 "library" response. Combined with the new "qXfer:libraries:read"
1997 packet, this response allows GDB to debug shared libraries on targets
1998 where the operating system manages the list of loaded libraries (e.g.
1999 Windows and SymbianOS).
2001 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2002 (DLLs) on Windows and Windows CE targets.
2004 * GDB now supports a faster verification that a .debug file matches its binary
2005 according to its build-id signature, if the signature is present.
2011 Enable or disable hardware flow control (RTS/CTS) on the serial port
2012 when debugging using remote targets.
2014 set mem inaccessible-by-default
2015 show mem inaccessible-by-default
2016 If the target supplies a memory map, for instance via the remote
2017 protocol's "qXfer:memory-map:read" packet, setting this variable
2018 prevents GDB from accessing memory outside the memory map. This
2019 is useful for targets with memory mapped registers or which react
2020 badly to accesses of unmapped address space.
2022 set breakpoint auto-hw
2023 show breakpoint auto-hw
2024 If the target supplies a memory map, for instance via the remote
2025 protocol's "qXfer:memory-map:read" packet, setting this variable
2026 lets GDB use hardware breakpoints automatically for memory regions
2027 where it can not use software breakpoints. This covers both the
2028 "break" command and internal breakpoints used for other commands
2029 including "next" and "finish".
2032 catch exception unhandled
2033 Stop the program execution when Ada exceptions are raised.
2036 Stop the program execution when an Ada assertion failed.
2040 Set an alternate system root for target files. This is a more
2041 general version of "set solib-absolute-prefix", which is now
2042 an alias to "set sysroot".
2045 Provide extended SPU facility status information. This set of
2046 commands is available only when debugging the Cell/B.E. SPU
2049 * New native configurations
2051 OpenBSD/sh sh*-*openbsd*
2054 unset tdesc filename
2056 Use the specified local file as an XML target description, and do
2057 not query the target for its built-in description.
2061 OpenBSD/sh sh*-*-openbsd*
2062 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2063 Toshiba Media Processor mep-elf
2065 * New remote packets
2068 Ignore the specified signals; pass them directly to the debugged program
2069 without stopping other threads or reporting them to GDB.
2071 qXfer:features:read:
2072 Read an XML target description from the target, which describes its
2077 Read or write contents of an spufs file on the target system. These
2078 packets are available only on the Cell/B.E. SPU architecture.
2080 qXfer:libraries:read:
2081 Report the loaded shared libraries. Combined with new "T" packet
2082 response, this packet allows GDB to debug shared libraries on
2083 targets where the operating system manages the list of loaded
2084 libraries (e.g. Windows and SymbianOS).
2088 Support for these obsolete configurations has been removed.
2096 i[34567]86-*-lynxos*
2097 i[34567]86-*-netware*
2098 i[34567]86-*-sco3.2v5*
2099 i[34567]86-*-sco3.2v4*
2101 i[34567]86-*-sysv4.2*
2104 i[34567]86-*-unixware2*
2105 i[34567]86-*-unixware*
2114 * Other removed features
2121 Various m68k-only ROM monitors.
2128 Various Renesas ROM monitors and debugging interfaces for SH and
2133 Support for a Macraigor serial interface to on-chip debugging.
2134 GDB does not directly support the newer parallel or USB
2139 A debug information format. The predecessor to DWARF 2 and
2140 DWARF 3, which are still supported.
2142 Support for the HP aCC compiler on HP-UX/PA-RISC
2144 SOM-encapsulated symbolic debugging information, automatic
2145 invocation of pxdb, and the aCC custom C++ ABI. This does not
2146 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2147 with aCC can still be debugged on an assembly level.
2149 MIPS ".pdr" sections
2151 A MIPS-specific format used to describe stack frame layout
2152 in debugging information.
2156 GDB could work with an older version of Guile to debug
2157 the interpreter and Scheme programs running in it.
2159 set mips stack-arg-size
2160 set mips saved-gpreg-size
2162 Use "set mips abi" to control parameter passing for MIPS.
2164 *** Changes in GDB 6.6
2169 Cell Broadband Engine SPU spu-elf
2171 * GDB can now be configured as a cross-debugger targeting native Windows
2172 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2173 running on a Windows system over TCP/IP to debug Windows programs.
2175 * The GDB remote stub, gdbserver, has been updated to support Windows and
2176 Cygwin debugging. Both single-threaded and multi-threaded programs are
2179 * The "set trust-readonly-sections" command works again. This command was
2180 broken in GDB 6.3, 6.4, and 6.5.
2182 * The "load" command now supports writing to flash memory, if the remote
2183 stub provides the required support.
2185 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2186 longer requires symbolic debug information (e.g. DWARF-2).
2191 unset substitute-path
2192 show substitute-path
2193 Manage a list of substitution rules that GDB uses to rewrite the name
2194 of the directories where the sources are located. This can be useful
2195 for instance when the sources were moved to a different location
2196 between compilation and debugging.
2200 Print each CLI command as it is executed. Each command is prefixed with
2201 a number of `+' symbols representing the nesting depth.
2202 The source command now has a `-v' option to enable the same feature.
2206 The ARM Demon monitor support (RDP protocol, "target rdp").
2208 Kernel Object Display, an embedded debugging feature which only worked with
2209 an obsolete version of Cisco IOS.
2211 The 'set download-write-size' and 'show download-write-size' commands.
2213 * New remote packets
2216 Tell a stub about GDB client features, and request remote target features.
2217 The first feature implemented is PacketSize, which allows the target to
2218 specify the size of packets it can handle - to minimize the number of
2219 packets required and improve performance when connected to a remote
2223 Fetch an OS auxilliary vector from the remote stub. This packet is a
2224 more efficient replacement for qPart:auxv:read.
2226 qXfer:memory-map:read:
2227 Fetch a memory map from the remote stub, including information about
2228 RAM, ROM, and flash memory devices.
2233 Erase and program a flash memory device.
2235 * Removed remote packets
2238 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2239 used it, and only gdbserver implemented it.
2241 *** Changes in GDB 6.5
2245 Renesas M32C/M16C m32c-elf
2247 Morpho Technologies ms1 ms1-elf
2251 init-if-undefined Initialize a convenience variable, but
2252 only if it doesn't already have a value.
2254 The following commands are presently only implemented for native GNU/Linux:
2256 checkpoint Save a snapshot of the program state.
2258 restart <n> Return the program state to a
2259 previously saved state.
2261 info checkpoints List currently saved checkpoints.
2263 delete-checkpoint <n> Delete a previously saved checkpoint.
2265 set|show detach-on-fork Tell gdb whether to detach from a newly
2266 forked process, or to keep debugging it.
2268 info forks List forks of the user program that
2269 are available to be debugged.
2271 fork <n> Switch to debugging one of several
2272 forks of the user program that are
2273 available to be debugged.
2275 delete-fork <n> Delete a fork from the list of forks
2276 that are available to be debugged (and
2277 kill the forked process).
2279 detach-fork <n> Delete a fork from the list of forks
2280 that are available to be debugged (and
2281 allow the process to continue).
2285 Morpho Technologies ms2 ms1-elf
2287 * Improved Windows host support
2289 GDB now builds as a cross debugger hosted on i686-mingw32, including
2290 native console support, and remote communications using either
2291 network sockets or serial ports.
2293 * Improved Modula-2 language support
2295 GDB can now print most types in the Modula-2 syntax. This includes:
2296 basic types, set types, record types, enumerated types, range types,
2297 pointer types and ARRAY types. Procedure var parameters are correctly
2298 printed and hexadecimal addresses and character constants are also
2299 written in the Modula-2 syntax. Best results can be obtained by using
2300 GNU Modula-2 together with the -gdwarf-2 command line option.
2304 The ARM rdi-share module.
2306 The Netware NLM debug server.
2308 *** Changes in GDB 6.4
2310 * New native configurations
2312 OpenBSD/arm arm*-*-openbsd*
2313 OpenBSD/mips64 mips64-*-openbsd*
2317 Morpho Technologies ms1 ms1-elf
2319 * New command line options
2321 --batch-silent As for --batch, but totally silent.
2322 --return-child-result The debugger will exist with the same value
2323 the child (debugged) program exited with.
2324 --eval-command COMMAND, -ex COMMAND
2325 Execute a single GDB CLI command. This may be
2326 specified multiple times and in conjunction
2327 with the --command (-x) option.
2329 * Deprecated commands removed
2331 The following commands, that were deprecated in 2000, have been
2335 set|show arm disassembly-flavor set|show arm disassembler
2336 othernames set arm disassembler
2337 set|show remotedebug set|show debug remote
2338 set|show archdebug set|show debug arch
2339 set|show eventdebug set|show debug event
2342 * New BSD user-level threads support
2344 It is now possible to debug programs using the user-level threads
2345 library on OpenBSD and FreeBSD. Currently supported (target)
2348 FreeBSD/amd64 x86_64-*-freebsd*
2349 FreeBSD/i386 i386-*-freebsd*
2350 OpenBSD/i386 i386-*-openbsd*
2352 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2353 are not yet supported.
2355 * New support for Matsushita MN10300 w/sim added
2356 (Work in progress). mn10300-elf.
2358 * REMOVED configurations and files
2360 VxWorks and the XDR protocol *-*-vxworks
2361 Motorola MCORE mcore-*-*
2362 National Semiconductor NS32000 ns32k-*-*
2364 * New "set print array-indexes" command
2366 After turning this setting "on", GDB prints the index of each element
2367 when displaying arrays. The default is "off" to preserve the previous
2370 * VAX floating point support
2372 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2374 * User-defined command support
2376 In addition to using $arg0..$arg9 for argument passing, it is now possible
2377 to use $argc to determine now many arguments have been passed. See the
2378 section on user-defined commands in the user manual for more information.
2380 *** Changes in GDB 6.3:
2382 * New command line option
2384 GDB now accepts -l followed by a number to set the timeout for remote
2387 * GDB works with GCC -feliminate-dwarf2-dups
2389 GDB now supports a more compact representation of DWARF-2 debug
2390 information using DW_FORM_ref_addr references. These are produced
2391 by GCC with the option -feliminate-dwarf2-dups and also by some
2392 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2393 to use -feliminate-dwarf2-dups.
2395 * Internationalization
2397 When supported by the host system, GDB will be built with
2398 internationalization (libintl). The task of marking up the sources is
2399 continued, we're looking forward to our first translation.
2403 Initial support for debugging programs compiled with the GNAT
2404 implementation of the Ada programming language has been integrated
2405 into GDB. In this release, support is limited to expression evaluation.
2407 * New native configurations
2409 GNU/Linux/m32r m32r-*-linux-gnu
2413 GDB's remote protocol now includes support for the 'p' packet. This
2414 packet is used to fetch individual registers from a remote inferior.
2416 * END-OF-LIFE registers[] compatibility module
2418 GDB's internal register infrastructure has been completely rewritten.
2419 The new infrastructure making possible the implementation of key new
2420 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2423 GDB 6.3 will be the last release to include the the registers[]
2424 compatibility module that allowed out-of-date configurations to
2425 continue to work. This change directly impacts the following
2435 powerpc bdm protocol
2437 Unless there is activity to revive these configurations, they will be
2438 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2440 * OBSOLETE configurations and files
2442 Configurations that have been declared obsolete in this release have
2443 been commented out. Unless there is activity to revive these
2444 configurations, the next release of GDB will have their sources
2445 permanently REMOVED.
2454 *** Changes in GDB 6.2.1:
2456 * MIPS `break main; run' gave an heuristic-fence-post warning
2458 When attempting to run even a simple program, a warning about
2459 heuristic-fence-post being hit would be reported. This problem has
2462 * MIPS IRIX 'long double' crashed GDB
2464 When examining a long double variable, GDB would get a segmentation
2465 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2466 IRIX long double values).
2470 A bug in the VAX stack code was causing problems with the "next"
2471 command. This problem has been fixed.
2473 *** Changes in GDB 6.2:
2475 * Fix for ``many threads''
2477 On GNU/Linux systems that use the NPTL threads library, a program
2478 rapidly creating and deleting threads would confuse GDB leading to the
2481 ptrace: No such process.
2482 thread_db_get_info: cannot get thread info: generic error
2484 This problem has been fixed.
2486 * "-async" and "-noasync" options removed.
2488 Support for the broken "-noasync" option has been removed (it caused
2491 * New ``start'' command.
2493 This command runs the program until the begining of the main procedure.
2495 * New BSD Kernel Data Access Library (libkvm) interface
2497 Using ``target kvm'' it is now possible to debug kernel core dumps and
2498 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2499 platforms. Currently supported (native-only) configurations are:
2501 FreeBSD/amd64 x86_64-*-freebsd*
2502 FreeBSD/i386 i?86-*-freebsd*
2503 NetBSD/i386 i?86-*-netbsd*
2504 NetBSD/m68k m68*-*-netbsd*
2505 NetBSD/sparc sparc-*-netbsd*
2506 OpenBSD/amd64 x86_64-*-openbsd*
2507 OpenBSD/i386 i?86-*-openbsd*
2508 OpenBSD/m68k m68*-openbsd*
2509 OpenBSD/sparc sparc-*-openbsd*
2511 * Signal trampoline code overhauled
2513 Many generic problems with GDB's signal handling code have been fixed.
2514 These include: backtraces through non-contiguous stacks; recognition
2515 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2516 call; backtrace through a signal trampoline; step into and out of
2517 signal handlers; and single-stepping in the signal trampoline.
2519 Please note that kernel bugs are a limiting factor here. These
2520 features have been shown to work on an s390 GNU/Linux system that
2521 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2523 * Cygwin support for DWARF 2 added.
2525 * New native configurations
2527 GNU/Linux/hppa hppa*-*-linux*
2528 OpenBSD/hppa hppa*-*-openbsd*
2529 OpenBSD/m68k m68*-*-openbsd*
2530 OpenBSD/m88k m88*-*-openbsd*
2531 OpenBSD/powerpc powerpc-*-openbsd*
2532 NetBSD/vax vax-*-netbsd*
2533 OpenBSD/vax vax-*-openbsd*
2535 * END-OF-LIFE frame compatibility module
2537 GDB's internal frame infrastructure has been completely rewritten.
2538 The new infrastructure making it possible to support key new features
2539 including DWARF 2 Call Frame Information. To aid in the task of
2540 migrating old configurations to this new infrastructure, a
2541 compatibility module, that allowed old configurations to continue to
2542 work, was also included.
2544 GDB 6.2 will be the last release to include this frame compatibility
2545 module. This change directly impacts the following configurations:
2555 Unless there is activity to revive these configurations, they will be
2556 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2558 * REMOVED configurations and files
2560 Sun 3, running SunOS 3 m68*-*-sunos3*
2561 Sun 3, running SunOS 4 m68*-*-sunos4*
2562 Sun 2, running SunOS 3 m68000-*-sunos3*
2563 Sun 2, running SunOS 4 m68000-*-sunos4*
2564 Motorola 680x0 running LynxOS m68*-*-lynxos*
2565 AT&T 3b1/Unix pc m68*-att-*
2566 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2567 decstation mips-dec-* mips-little-*
2568 riscos mips-*-riscos* mips-*-sysv*
2569 sonymips mips-sony-*
2570 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2572 *** Changes in GDB 6.1.1:
2574 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2576 The TUI (Text-mode User Interface) is now built as part of a default
2577 GDB configuration. It is enabled by either selecting the TUI with the
2578 command line option "-i=tui" or by running the separate "gdbtui"
2579 program. For more information on the TUI, see the manual "Debugging
2582 * Pending breakpoint support (also included in GDB 6.1)
2584 Support has been added to allow you to specify breakpoints in shared
2585 libraries that have not yet been loaded. If a breakpoint location
2586 cannot be found, and the "breakpoint pending" option is set to auto,
2587 GDB queries you if you wish to make the breakpoint pending on a future
2588 shared-library load. If and when GDB resolves the breakpoint symbol,
2589 the pending breakpoint is removed as one or more regular breakpoints
2592 Pending breakpoints are very useful for GCJ Java debugging.
2594 * Fixed ISO-C build problems
2596 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2597 non ISO-C code that stopped them being built using a more strict ISO-C
2598 compiler (e.g., IBM's C compiler).
2600 * Fixed build problem on IRIX 5
2602 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2603 wasn't able to compile compile on an IRIX 5 system.
2605 * Added execute permission to gdb/gdbserver/configure
2607 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2608 permission. This bug would cause configure to fail on a number of
2609 systems (Solaris, IRIX). Ref: server/519.
2611 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2613 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2614 has been updated to use constant array sizes.
2616 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2618 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2619 its generated DWARF Call Frame Info. This encoding was causing GDB to
2620 panic, that panic has been fixed. Ref: gdb/1628.
2622 * Fixed a problem when examining parameters in shared library code.
2624 When examining parameters in optimized shared library code generated
2625 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2626 not available''. GDB now correctly displays the variable's value.
2628 *** Changes in GDB 6.1:
2630 * Removed --with-mmalloc
2632 Support for the mmalloc memory manager has been removed, as it
2633 conflicted with the internal gdb byte cache.
2635 * Changes in AMD64 configurations
2637 The AMD64 target now includes the %cs and %ss registers. As a result
2638 the AMD64 remote protocol has changed; this affects the floating-point
2639 and SSE registers. If you rely on those registers for your debugging,
2640 you should upgrade gdbserver on the remote side.
2642 * Revised SPARC target
2644 The SPARC target has been completely revised, incorporating the
2645 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2646 support for LynxOS and SunOS 4 has been dropped. Calling functions
2647 from within GDB on operating systems with a non-executable stack
2648 (Solaris, OpenBSD) now works.
2652 GDB has a new C++ demangler which does a better job on the mangled
2653 names generated by current versions of g++. It also runs faster, so
2654 with this and other changes gdb should now start faster on large C++
2657 * DWARF 2 Location Expressions
2659 GDB support for location expressions has been extended to support function
2660 arguments and frame bases. Older versions of GDB could crash when they
2663 * C++ nested types and namespaces
2665 GDB's support for nested types and namespaces in C++ has been
2666 improved, especially if you use the DWARF 2 debugging format. (This
2667 is the default for recent versions of GCC on most platforms.)
2668 Specifically, if you have a class "Inner" defined within a class or
2669 namespace "Outer", then GDB realizes that the class's name is
2670 "Outer::Inner", not simply "Inner". This should greatly reduce the
2671 frequency of complaints about not finding RTTI symbols. In addition,
2672 if you are stopped at inside of a function defined within a namespace,
2673 GDB modifies its name lookup accordingly.
2675 * New native configurations
2677 NetBSD/amd64 x86_64-*-netbsd*
2678 OpenBSD/amd64 x86_64-*-openbsd*
2679 OpenBSD/alpha alpha*-*-openbsd*
2680 OpenBSD/sparc sparc-*-openbsd*
2681 OpenBSD/sparc64 sparc64-*-openbsd*
2683 * New debugging protocols
2685 M32R with SDI protocol m32r-*-elf*
2687 * "set prompt-escape-char" command deleted.
2689 The command "set prompt-escape-char" has been deleted. This command,
2690 and its very obscure effet on GDB's prompt, was never documented,
2691 tested, nor mentioned in the NEWS file.
2693 * OBSOLETE configurations and files
2695 Configurations that have been declared obsolete in this release have
2696 been commented out. Unless there is activity to revive these
2697 configurations, the next release of GDB will have their sources
2698 permanently REMOVED.
2700 Sun 3, running SunOS 3 m68*-*-sunos3*
2701 Sun 3, running SunOS 4 m68*-*-sunos4*
2702 Sun 2, running SunOS 3 m68000-*-sunos3*
2703 Sun 2, running SunOS 4 m68000-*-sunos4*
2704 Motorola 680x0 running LynxOS m68*-*-lynxos*
2705 AT&T 3b1/Unix pc m68*-att-*
2706 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2707 decstation mips-dec-* mips-little-*
2708 riscos mips-*-riscos* mips-*-sysv*
2709 sonymips mips-sony-*
2710 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2712 * REMOVED configurations and files
2714 SGI Irix-4.x mips-sgi-irix4 or iris4
2715 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2716 Z8000 simulator z8k-zilog-none or z8ksim
2717 Matsushita MN10200 w/simulator mn10200-*-*
2718 H8/500 simulator h8500-hitachi-hms or h8500hms
2719 HP/PA running BSD hppa*-*-bsd*
2720 HP/PA running OSF/1 hppa*-*-osf*
2721 HP/PA Pro target hppa*-*-pro*
2722 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2723 386BSD i[3456]86-*-bsd*
2724 Sequent family i[3456]86-sequent-sysv4*
2725 i[3456]86-sequent-sysv*
2726 i[3456]86-sequent-bsd*
2727 SPARC running LynxOS sparc-*-lynxos*
2728 SPARC running SunOS 4 sparc-*-sunos4*
2729 Tsqware Sparclet sparclet-*-*
2730 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2732 *** Changes in GDB 6.0:
2736 Support for debugging the Objective-C programming language has been
2737 integrated into GDB.
2739 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2741 DWARF 2's Call Frame Information makes available compiler generated
2742 information that more exactly describes the program's run-time stack.
2743 By using this information, GDB is able to provide more robust stack
2746 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2747 have been updated to use a new backtrace mechanism which includes
2748 DWARF 2 CFI support.
2752 GDB's remote protocol has been extended to include support for hosted
2753 file I/O (where the remote target uses GDB's file system). See GDB's
2754 remote protocol documentation for details.
2756 * All targets using the new architecture framework.
2758 All of GDB's targets have been updated to use the new internal
2759 architecture framework. The way is now open for future GDB releases
2760 to include cross-architecture native debugging support (i386 on amd64,
2763 * GNU/Linux's Thread Local Storage (TLS)
2765 GDB now includes support for for the GNU/Linux implementation of
2766 per-thread variables.
2768 * GNU/Linux's Native POSIX Thread Library (NPTL)
2770 GDB's thread code has been updated to work with either the new
2771 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2773 * Separate debug info.
2775 GDB, in conjunction with BINUTILS, now supports a mechanism for
2776 automatically loading debug information from a separate file. Instead
2777 of shipping full debug and non-debug versions of system libraries,
2778 system integrators can now instead ship just the stripped libraries
2779 and optional debug files.
2781 * DWARF 2 Location Expressions
2783 DWARF 2 Location Expressions allow the compiler to more completely
2784 describe the location of variables (even in optimized code) to the
2787 GDB now includes preliminary support for location expressions (support
2788 for DW_OP_piece is still missing).
2792 A number of long standing bugs that caused GDB to die while starting a
2793 Java application have been fixed. GDB's Java support is now
2794 considered "useable".
2796 * GNU/Linux support for fork, vfork, and exec.
2798 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2799 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2802 * GDB supports logging output to a file
2804 There are two new commands, "set logging" and "show logging", which can be
2805 used to capture GDB's output to a file.
2807 * The meaning of "detach" has changed for gdbserver
2809 The "detach" command will now resume the application, as documented. To
2810 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2813 * d10v, m68hc11 `regs' command deprecated
2815 The `info registers' command has been updated so that it displays the
2816 registers using a format identical to the old `regs' command.
2820 A new command, "maint set profile on/off", has been added. This command can
2821 be used to enable or disable profiling while running GDB, to profile a
2822 session or a set of commands. In addition there is a new configure switch,
2823 "--enable-profiling", which will cause GDB to be compiled with profiling
2824 data, for more informative profiling results.
2826 * Default MI syntax changed to "mi2".
2828 The default MI (machine interface) syntax, enabled by the command line
2829 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2830 "mi1", can be enabled by specifying the option "-i=mi1".
2832 Support for the original "mi0" syntax (included in GDB 5.0) has been
2835 Fix for gdb/192: removed extraneous space when displaying frame level.
2836 Fix for gdb/672: update changelist is now output in mi list format.
2837 Fix for gdb/702: a -var-assign that updates the value now shows up
2838 in a subsequent -var-update.
2840 * New native configurations.
2842 FreeBSD/amd64 x86_64-*-freebsd*
2844 * Multi-arched targets.
2846 HP/PA HPUX11 hppa*-*-hpux*
2847 Renesas M32R/D w/simulator m32r-*-elf*
2849 * OBSOLETE configurations and files
2851 Configurations that have been declared obsolete in this release have
2852 been commented out. Unless there is activity to revive these
2853 configurations, the next release of GDB will have their sources
2854 permanently REMOVED.
2856 Z8000 simulator z8k-zilog-none or z8ksim
2857 Matsushita MN10200 w/simulator mn10200-*-*
2858 H8/500 simulator h8500-hitachi-hms or h8500hms
2859 HP/PA running BSD hppa*-*-bsd*
2860 HP/PA running OSF/1 hppa*-*-osf*
2861 HP/PA Pro target hppa*-*-pro*
2862 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2863 Sequent family i[3456]86-sequent-sysv4*
2864 i[3456]86-sequent-sysv*
2865 i[3456]86-sequent-bsd*
2866 Tsqware Sparclet sparclet-*-*
2867 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2869 * REMOVED configurations and files
2872 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2873 IBM AIX PS/2 i[3456]86-*-aix
2874 i386 running Mach 3.0 i[3456]86-*-mach3*
2875 i386 running Mach i[3456]86-*-mach*
2876 i386 running OSF/1 i[3456]86-*osf1mk*
2877 HP/Apollo 68k Family m68*-apollo*-sysv*,
2879 m68*-hp-bsd*, m68*-hp-hpux*
2880 Argonaut Risc Chip (ARC) arc-*-*
2881 Mitsubishi D30V d30v-*-*
2882 Fujitsu FR30 fr30-*-elf*
2883 OS/9000 i[34]86-*-os9k
2884 I960 with MON960 i960-*-coff
2886 * MIPS $fp behavior changed
2888 The convenience variable $fp, for the MIPS, now consistently returns
2889 the address of the current frame's base. Previously, depending on the
2890 context, $fp could refer to either $sp or the current frame's base
2891 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2892 The GNU Source-Level Debugger''.
2894 *** Changes in GDB 5.3:
2896 * GNU/Linux shared library multi-threaded performance improved.
2898 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2899 `/proc', in preference to `ptrace' for memory reads. This may result
2900 in an improvement in the start-up time of multi-threaded, shared
2901 library applications when run under GDB. One GDB user writes: ``loads
2902 shared libs like mad''.
2904 * ``gdbserver'' now supports multi-threaded applications on some targets
2906 Support for debugging multi-threaded applications which use
2907 the GNU/Linux LinuxThreads package has been added for
2908 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2909 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2911 * GDB now supports C/C++ preprocessor macros.
2913 GDB now expands preprocessor macro invocations in C/C++ expressions,
2914 and provides various commands for showing macro definitions and how
2917 The new command `macro expand EXPRESSION' expands any macro
2918 invocations in expression, and shows the result.
2920 The new command `show macro MACRO-NAME' shows the definition of the
2921 macro named MACRO-NAME, and where it was defined.
2923 Most compilers don't include information about macros in the debugging
2924 information by default. In GCC 3.1, for example, you need to compile
2925 your program with the options `-gdwarf-2 -g3'. If the macro
2926 information is present in the executable, GDB will read it.
2928 * Multi-arched targets.
2930 DEC Alpha (partial) alpha*-*-*
2931 DEC VAX (partial) vax-*-*
2933 National Semiconductor NS32000 (partial) ns32k-*-*
2934 Motorola 68000 (partial) m68k-*-*
2935 Motorola MCORE mcore-*-*
2939 Fujitsu FRV architecture added by Red Hat frv*-*-*
2942 * New native configurations
2944 Alpha NetBSD alpha*-*-netbsd*
2945 SH NetBSD sh*-*-netbsdelf*
2946 MIPS NetBSD mips*-*-netbsd*
2947 UltraSPARC NetBSD sparc64-*-netbsd*
2949 * OBSOLETE configurations and files
2951 Configurations that have been declared obsolete in this release have
2952 been commented out. Unless there is activity to revive these
2953 configurations, the next release of GDB will have their sources
2954 permanently REMOVED.
2956 Mitsubishi D30V d30v-*-*
2957 OS/9000 i[34]86-*-os9k
2958 IBM AIX PS/2 i[3456]86-*-aix
2959 Fujitsu FR30 fr30-*-elf*
2960 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2961 Argonaut Risc Chip (ARC) arc-*-*
2962 i386 running Mach 3.0 i[3456]86-*-mach3*
2963 i386 running Mach i[3456]86-*-mach*
2964 i386 running OSF/1 i[3456]86-*osf1mk*
2965 HP/Apollo 68k Family m68*-apollo*-sysv*,
2967 m68*-hp-bsd*, m68*-hp-hpux*
2968 I960 with MON960 i960-*-coff
2970 * OBSOLETE languages
2972 CHILL, a Pascal like language used by telecommunications companies.
2974 * REMOVED configurations and files
2976 AMD 29k family via UDI a29k-amd-udi, udi29k
2977 A29K VxWorks a29k-*-vxworks
2978 AMD 29000 embedded, using EBMON a29k-none-none
2979 AMD 29000 embedded with COFF a29k-none-coff
2980 AMD 29000 embedded with a.out a29k-none-aout
2982 testsuite/gdb.hp/gdb.threads-hp/ directory
2984 * New command "set max-user-call-depth <nnn>"
2986 This command allows the user to limit the call depth of user-defined
2987 commands. The default is 1024.
2989 * Changes in FreeBSD/i386 native debugging.
2991 Support for the "generate-core-file" has been added.
2993 * New commands "dump", "append", and "restore".
2995 These commands allow data to be copied from target memory
2996 to a bfd-format or binary file (dump and append), and back
2997 from a file into memory (restore).
2999 * Improved "next/step" support on multi-processor Alpha Tru64.
3001 The previous single-step mechanism could cause unpredictable problems,
3002 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3003 of a software single-step mechanism prevents this.
3005 *** Changes in GDB 5.2.1:
3013 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3014 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3015 Fix, by Joel Brobecker imported from mainline.
3017 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3018 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3019 Fix, by Fred Fish, imported from mainline.
3021 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3022 Surprisingly enough, it works now.
3023 By Michal Ludvig, imported from mainline.
3025 i386 hardware watchpoint support:
3026 avoid misses on second run for some targets.
3027 By Pierre Muller, imported from mainline.
3029 *** Changes in GDB 5.2:
3031 * New command "set trust-readonly-sections on[off]".
3033 This command is a hint that tells gdb that read-only sections
3034 really are read-only (ie. that their contents will not change).
3035 In this mode, gdb will go to the object file rather than the
3036 target to read memory from read-only sections (such as ".text").
3037 This can be a significant performance improvement on some
3038 (notably embedded) targets.
3040 * New command "generate-core-file" (or "gcore").
3042 This new gdb command allows the user to drop a core file of the child
3043 process state at any time. So far it's been implemented only for
3044 GNU/Linux and Solaris, but should be relatively easily ported to other
3045 hosts. Argument is core file name (defaults to core.<pid>).
3047 * New command line option
3049 GDB now accepts --pid or -p followed by a process id.
3051 * Change in command line behavior -- corefiles vs. process ids.
3053 There is a subtle behavior in the way in which GDB handles
3054 command line arguments. The first non-flag argument is always
3055 a program to debug, but the second non-flag argument may either
3056 be a corefile or a process id. Previously, GDB would attempt to
3057 open the second argument as a corefile, and if that failed, would
3058 issue a superfluous error message and then attempt to attach it as
3059 a process. Now, if the second argument begins with a non-digit,
3060 it will be treated as a corefile. If it begins with a digit,
3061 GDB will attempt to attach it as a process, and if no such process
3062 is found, will then attempt to open it as a corefile.
3064 * Changes in ARM configurations.
3066 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3067 configuration is fully multi-arch.
3069 * New native configurations
3071 ARM NetBSD arm*-*-netbsd*
3072 x86 OpenBSD i[3456]86-*-openbsd*
3073 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3074 Sparc64 running FreeBSD sparc64-*-freebsd*
3078 Sanyo XStormy16 xstormy16-elf
3080 * OBSOLETE configurations and files
3082 Configurations that have been declared obsolete in this release have
3083 been commented out. Unless there is activity to revive these
3084 configurations, the next release of GDB will have their sources
3085 permanently REMOVED.
3087 AMD 29k family via UDI a29k-amd-udi, udi29k
3088 A29K VxWorks a29k-*-vxworks
3089 AMD 29000 embedded, using EBMON a29k-none-none
3090 AMD 29000 embedded with COFF a29k-none-coff
3091 AMD 29000 embedded with a.out a29k-none-aout
3093 testsuite/gdb.hp/gdb.threads-hp/ directory
3095 * REMOVED configurations and files
3097 TI TMS320C80 tic80-*-*
3099 PowerPC Solaris powerpcle-*-solaris*
3100 PowerPC Windows NT powerpcle-*-cygwin32
3101 PowerPC Netware powerpc-*-netware*
3102 Harris/CXUX m88k m88*-harris-cxux*
3103 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3104 ns32k-utek-sysv* ns32k-utek-*
3105 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3106 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3107 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3108 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3109 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3111 * Changes to command line processing
3113 The new `--args' feature can be used to specify command-line arguments
3114 for the inferior from gdb's command line.
3116 * Changes to key bindings
3118 There is a new `operate-and-get-next' function bound to `C-o'.
3120 *** Changes in GDB 5.1.1
3122 Fix compile problem on DJGPP.
3124 Fix a problem with floating-point registers on the i386 being
3127 Fix to stop GDB crashing on .debug_str debug info.
3129 Numerous documentation fixes.
3131 Numerous testsuite fixes.
3133 *** Changes in GDB 5.1:
3135 * New native configurations
3137 Alpha FreeBSD alpha*-*-freebsd*
3138 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3139 MIPS GNU/Linux mips*-*-linux*
3140 MIPS SGI Irix 6.x mips*-sgi-irix6*
3141 ia64 AIX ia64-*-aix*
3142 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3146 Motorola 68HC11 and 68HC12 m68hc11-elf
3148 UltraSparc running GNU/Linux sparc64-*-linux*
3150 * OBSOLETE configurations and files
3152 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3153 Harris/CXUX m88k m88*-harris-cxux*
3154 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3155 ns32k-utek-sysv* ns32k-utek-*
3156 TI TMS320C80 tic80-*-*
3158 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3159 PowerPC Solaris powerpcle-*-solaris*
3160 PowerPC Windows NT powerpcle-*-cygwin32
3161 PowerPC Netware powerpc-*-netware*
3162 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3163 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3164 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3165 Apple Macintosh (MPW) host N/A
3167 stuff.c (Program to stuff files into a specially prepared space in kdb)
3168 kdb-start.c (Main loop for the standalone kernel debugger)
3170 Configurations that have been declared obsolete in this release have
3171 been commented out. Unless there is activity to revive these
3172 configurations, the next release of GDB will have their sources
3173 permanently REMOVED.
3175 * REMOVED configurations and files
3177 Altos 3068 m68*-altos-*
3178 Convex c1-*-*, c2-*-*
3180 ARM RISCix arm-*-* (as host)
3184 * GDB has been converted to ISO C.
3186 GDB's source code has been converted to ISO C. In particular, the
3187 sources are fully protoized, and rely on standard headers being
3192 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3194 * The MI enabled by default.
3196 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3197 revised and enabled by default. Packages which use GDB as a debugging
3198 engine behind a UI or another front end are encouraged to switch to
3199 using the GDB/MI interface, instead of the old annotations interface
3200 which is now deprecated.
3202 * Support for debugging Pascal programs.
3204 GDB now includes support for debugging Pascal programs. The following
3205 main features are supported:
3207 - Pascal-specific data types such as sets;
3209 - automatic recognition of Pascal sources based on file-name
3212 - Pascal-style display of data types, variables, and functions;
3214 - a Pascal expression parser.
3216 However, some important features are not yet supported.
3218 - Pascal string operations are not supported at all;
3220 - there are some problems with boolean types;
3222 - Pascal type hexadecimal constants are not supported
3223 because they conflict with the internal variables format;
3225 - support for Pascal objects and classes is not full yet;
3227 - unlike Pascal, GDB is case-sensitive for symbol names.
3229 * Changes in completion.
3231 Commands such as `shell', `run' and `set args', which pass arguments
3232 to inferior programs, now complete on file names, similar to what
3233 users expect at the shell prompt.
3235 Commands which accept locations, such as `disassemble', `print',
3236 `breakpoint', `until', etc. now complete on filenames as well as
3237 program symbols. Thus, if you type "break foob TAB", and the source
3238 files linked into the programs include `foobar.c', that file name will
3239 be one of the candidates for completion. However, file names are not
3240 considered for completion after you typed a colon that delimits a file
3241 name from a name of a function in that file, as in "break foo.c:bar".
3243 `set demangle-style' completes on available demangling styles.
3245 * New platform-independent commands:
3247 It is now possible to define a post-hook for a command as well as a
3248 hook that runs before the command. For more details, see the
3249 documentation of `hookpost' in the GDB manual.
3251 * Changes in GNU/Linux native debugging.
3253 Support for debugging multi-threaded programs has been completely
3254 revised for all platforms except m68k and sparc. You can now debug as
3255 many threads as your system allows you to have.
3257 Attach/detach is supported for multi-threaded programs.
3259 Support for SSE registers was added for x86. This doesn't work for
3260 multi-threaded programs though.
3262 * Changes in MIPS configurations.
3264 Multi-arch support is enabled for all MIPS configurations.
3266 GDB can now be built as native debugger on SGI Irix 6.x systems for
3267 debugging n32 executables. (Debugging 64-bit executables is not yet
3270 * Unified support for hardware watchpoints in all x86 configurations.
3272 Most (if not all) native x86 configurations support hardware-assisted
3273 breakpoints and watchpoints in a unified manner. This support
3274 implements debug register sharing between watchpoints, which allows to
3275 put a virtually infinite number of watchpoints on the same address,
3276 and also supports watching regions up to 16 bytes with several debug
3279 The new maintenance command `maintenance show-debug-regs' toggles
3280 debugging print-outs in functions that insert, remove, and test
3281 watchpoints and hardware breakpoints.
3283 * Changes in the DJGPP native configuration.
3285 New command ``info dos sysinfo'' displays assorted information about
3286 the CPU, OS, memory, and DPMI server.
3288 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3289 display information about segment descriptors stored in GDT, LDT, and
3292 New commands ``info dos pde'' and ``info dos pte'' display entries
3293 from Page Directory and Page Tables (for now works with CWSDPMI only).
3294 New command ``info dos address-pte'' displays the Page Table entry for
3295 a given linear address.
3297 GDB can now pass command lines longer than 126 characters to the
3298 program being debugged (requires an update to the libdbg.a library
3299 which is part of the DJGPP development kit).
3301 DWARF2 debug info is now supported.
3303 It is now possible to `step' and `next' through calls to `longjmp'.
3305 * Changes in documentation.
3307 All GDB documentation was converted to GFDL, the GNU Free
3308 Documentation License.
3310 Tracepoints-related commands are now fully documented in the GDB
3313 TUI, the Text-mode User Interface, is now documented in the manual.
3315 Tracepoints-related commands are now fully documented in the GDB
3318 The "GDB Internals" manual now has an index. It also includes
3319 documentation of `ui_out' functions, GDB coding standards, x86
3320 hardware watchpoints, and memory region attributes.
3322 * GDB's version number moved to ``version.in''
3324 The Makefile variable VERSION has been replaced by the file
3325 ``version.in''. People creating GDB distributions should update the
3326 contents of this file.
3330 GUD support is now a standard part of the EMACS distribution.
3332 *** Changes in GDB 5.0:
3334 * Improved support for debugging FP programs on x86 targets
3336 Unified and much-improved support for debugging floating-point
3337 programs on all x86 targets. In particular, ``info float'' now
3338 displays the FP registers in the same format on all x86 targets, with
3339 greater level of detail.
3341 * Improvements and bugfixes in hardware-assisted watchpoints
3343 It is now possible to watch array elements, struct members, and
3344 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3345 on x86 targets no longer erroneously trigger when the address is
3348 * Improvements in the native DJGPP version of GDB
3350 The distribution now includes all the scripts and auxiliary files
3351 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3352 machines ``out of the box''.
3354 The DJGPP version can now debug programs that use signals. It is
3355 possible to catch signals that happened in the debuggee, deliver
3356 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3357 would kill the program being debugged.) Programs that hook hardware
3358 interrupts (keyboard, timer, etc.) can also be debugged.
3360 It is now possible to debug DJGPP programs that redirect their
3361 standard handles or switch them to raw (as opposed to cooked) mode, or
3362 even close them. The command ``run < foo > bar'' works as expected,
3363 and ``info terminal'' reports useful information about the debuggee's
3364 terminal, including raw/cooked mode, redirection, etc.
3366 The DJGPP version now uses termios functions for console I/O, which
3367 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3370 DOS-style file names with drive letters are now fully supported by
3373 It is now possible to debug DJGPP programs that switch their working
3374 directory. It is also possible to rerun the debuggee any number of
3375 times without restarting GDB; thus, you can use the same setup,
3376 breakpoints, etc. for many debugging sessions.
3378 * New native configurations
3380 ARM GNU/Linux arm*-*-linux*
3381 PowerPC GNU/Linux powerpc-*-linux*
3385 Motorola MCore mcore-*-*
3386 x86 VxWorks i[3456]86-*-vxworks*
3387 PowerPC VxWorks powerpc-*-vxworks*
3388 TI TMS320C80 tic80-*-*
3390 * OBSOLETE configurations
3392 Altos 3068 m68*-altos-*
3393 Convex c1-*-*, c2-*-*
3395 ARM RISCix arm-*-* (as host)
3398 Configurations that have been declared obsolete will be commented out,
3399 but the code will be left in place. If there is no activity to revive
3400 these configurations before the next release of GDB, the sources will
3401 be permanently REMOVED.
3403 * Gould support removed
3405 Support for the Gould PowerNode and NP1 has been removed.
3407 * New features for SVR4
3409 On SVR4 native platforms (such as Solaris), if you attach to a process
3410 without first loading a symbol file, GDB will now attempt to locate and
3411 load symbols from the running process's executable file.
3413 * Many C++ enhancements
3415 C++ support has been greatly improved. Overload resolution now works properly
3416 in almost all cases. RTTI support is on the way.
3418 * Remote targets can connect to a sub-program
3420 A popen(3) style serial-device has been added. This device starts a
3421 sub-process (such as a stand-alone simulator) and then communicates
3422 with that. The sub-program to run is specified using the syntax
3423 ``|<program> <args>'' vis:
3425 (gdb) set remotedebug 1
3426 (gdb) target extended-remote |mn10300-elf-sim program-args
3428 * MIPS 64 remote protocol
3430 A long standing bug in the mips64 remote protocol where by GDB
3431 expected certain 32 bit registers (ex SR) to be transfered as 32
3432 instead of 64 bits has been fixed.
3434 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3435 added to provide backward compatibility with older versions of GDB.
3437 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3439 The command ``set remotebinarydownload'' command has been replaced by
3440 ``set remote X-packet''. Other commands in ``set remote'' family
3441 include ``set remote P-packet''.
3443 * Breakpoint commands accept ranges.
3445 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3446 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3447 ``tracepoint passcount'' also accepts a range of tracepoints.
3449 * ``apropos'' command added.
3451 The ``apropos'' command searches through command names and
3452 documentation strings, printing out matches, making it much easier to
3453 try to find a command that does what you are looking for.
3457 A new machine oriented interface (MI) has been added to GDB. This
3458 interface is designed for debug environments running GDB as a separate
3459 process. This is part of the long term libGDB project. See the
3460 "GDB/MI" chapter of the GDB manual for further information. It can be
3461 enabled by configuring with:
3463 .../configure --enable-gdbmi
3465 *** Changes in GDB-4.18:
3467 * New native configurations
3469 HP-UX 10.20 hppa*-*-hpux10.20
3470 HP-UX 11.x hppa*-*-hpux11.0*
3471 M68K GNU/Linux m68*-*-linux*
3475 Fujitsu FR30 fr30-*-elf*
3476 Intel StrongARM strongarm-*-*
3477 Mitsubishi D30V d30v-*-*
3479 * OBSOLETE configurations
3481 Gould PowerNode, NP1 np1-*-*, pn-*-*
3483 Configurations that have been declared obsolete will be commented out,
3484 but the code will be left in place. If there is no activity to revive
3485 these configurations before the next release of GDB, the sources will
3486 be permanently REMOVED.
3490 As a compatibility experiment, GDB's source files buildsym.h and
3491 buildsym.c have been converted to pure standard C, no longer
3492 containing any K&R compatibility code. We believe that all systems in
3493 use today either come with a standard C compiler, or have a GCC port
3494 available. If this is not true, please report the affected
3495 configuration to bug-gdb@gnu.org immediately. See the README file for
3496 information about getting a standard C compiler if you don't have one
3501 GDB now uses readline 2.2.
3503 * set extension-language
3505 You can now control the mapping between filename extensions and source
3506 languages by using the `set extension-language' command. For instance,
3507 you can ask GDB to treat .c files as C++ by saying
3508 set extension-language .c c++
3509 The command `info extensions' lists all of the recognized extensions
3510 and their associated languages.
3512 * Setting processor type for PowerPC and RS/6000
3514 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3515 you can use the `set processor' command to specify what variant of the
3516 PowerPC family you are debugging. The command
3520 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3521 following PowerPC and RS6000 variants:
3523 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3524 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3526 403GC IBM PowerPC 403GC
3527 505 Motorola PowerPC 505
3528 860 Motorola PowerPC 860 or 850
3529 601 Motorola PowerPC 601
3530 602 Motorola PowerPC 602
3531 603 Motorola/IBM PowerPC 603 or 603e
3532 604 Motorola PowerPC 604 or 604e
3533 750 Motorola/IBM PowerPC 750 or 750
3535 At the moment, this command just tells GDB what to name the
3536 special-purpose processor registers. Since almost all the affected
3537 registers are inaccessible to user-level programs, this command is
3538 only useful for remote debugging in its present form.
3542 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3543 more extensive support for HP-UX. Added features include shared
3544 library support, kernel threads and hardware watchpoints for 11.00,
3545 support for HP's ANSI C and C++ compilers, and a compatibility mode
3546 for xdb and dbx commands.
3550 HP's donation includes the new concept of catchpoints, which is a
3551 generalization of the old catch command. On HP-UX, it is now possible
3552 to catch exec, fork, and vfork, as well as library loading.
3554 This means that the existing catch command has changed; its first
3555 argument now specifies the type of catch to be set up. See the
3556 output of "help catch" for a list of catchpoint types.
3558 * Debugging across forks
3560 On HP-UX, you can choose which process to debug when a fork() happens
3565 HP has donated a curses-based terminal user interface (TUI). To get
3566 it, build with --enable-tui. Although this can be enabled for any
3567 configuration, at present it only works for native HP debugging.
3569 * GDB remote protocol additions
3571 A new protocol packet 'X' that writes binary data is now available.
3572 Default behavior is to try 'X', then drop back to 'M' if the stub
3573 fails to respond. The settable variable `remotebinarydownload'
3574 allows explicit control over the use of 'X'.
3576 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3577 full 64-bit address. The command
3579 set remoteaddresssize 32
3581 can be used to revert to the old behaviour. For existing remote stubs
3582 the change should not be noticed, as the additional address information
3585 In order to assist in debugging stubs, you may use the maintenance
3586 command `packet' to send any text string to the stub. For instance,
3588 maint packet heythere
3590 sends the packet "$heythere#<checksum>". Note that it is very easy to
3591 disrupt a debugging session by sending the wrong packet at the wrong
3594 The compare-sections command allows you to compare section data on the
3595 target to what is in the executable file without uploading or
3596 downloading, by comparing CRC checksums.
3598 * Tracing can collect general expressions
3600 You may now collect general expressions at tracepoints. This requires
3601 further additions to the target-side stub; see tracepoint.c and
3602 doc/agentexpr.texi for further details.
3604 * mask-address variable for Mips
3606 For Mips targets, you may control the zeroing of the upper 32 bits of
3607 a 64-bit address by entering `set mask-address on'. This is mainly
3608 of interest to users of embedded R4xxx and R5xxx processors.
3610 * Higher serial baud rates
3612 GDB's serial code now allows you to specify baud rates 57600, 115200,
3613 230400, and 460800 baud. (Note that your host system may not be able
3614 to achieve all of these rates.)
3618 The i960 configuration now includes an initial implementation of a
3619 builtin simulator, contributed by Jim Wilson.
3622 *** Changes in GDB-4.17:
3624 * New native configurations
3626 Alpha GNU/Linux alpha*-*-linux*
3627 Unixware 2.x i[3456]86-unixware2*
3628 Irix 6.x mips*-sgi-irix6*
3629 PowerPC GNU/Linux powerpc-*-linux*
3630 PowerPC Solaris powerpcle-*-solaris*
3631 Sparc GNU/Linux sparc-*-linux*
3632 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3636 Argonaut Risc Chip (ARC) arc-*-*
3637 Hitachi H8/300S h8300*-*-*
3638 Matsushita MN10200 w/simulator mn10200-*-*
3639 Matsushita MN10300 w/simulator mn10300-*-*
3640 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3641 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3642 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3643 Mitsubishi D10V w/simulator d10v-*-*
3644 Mitsubishi M32R/D w/simulator m32r-*-elf*
3645 Tsqware Sparclet sparclet-*-*
3646 NEC V850 w/simulator v850-*-*
3648 * New debugging protocols
3650 ARM with RDI protocol arm*-*-*
3651 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3652 DDB and LSI variants of PMON protocol mips*-*-*
3653 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3654 PowerPC with SDS protocol powerpc{,le}-*-eabi
3655 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3659 All configurations can now understand and use the DWARF 2 debugging
3660 format. The choice is automatic, if the symbol file contains DWARF 2
3665 GDB now includes basic Java language support. This support is
3666 only useful with Java compilers that produce native machine code.
3668 * solib-absolute-prefix and solib-search-path
3670 For SunOS and SVR4 shared libraries, you may now set the prefix for
3671 loading absolute shared library symbol files, and the search path for
3672 locating non-absolute shared library symbol files.
3674 * Live range splitting
3676 GDB can now effectively debug code for which GCC has performed live
3677 range splitting as part of its optimization. See gdb/doc/LRS for
3678 more details on the expected format of the stabs information.
3682 GDB's support for the GNU Hurd, including thread debugging, has been
3683 updated to work with current versions of the Hurd.
3687 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3688 instruction set. ARM GDB automatically detects when Thumb
3689 instructions are in use, and adjusts disassembly and backtracing
3694 GDB's MIPS target configurations now handle the MIP16 16-bit
3699 GDB now includes support for overlays; if an executable has been
3700 linked such that multiple sections are based at the same address, GDB
3701 will decide which section to use for symbolic info. You can choose to
3702 control the decision manually, using overlay commands, or implement
3703 additional target-side support and use "overlay load-target" to bring
3704 in the overlay mapping. Do "help overlay" for more detail.
3708 The command "info symbol <address>" displays information about
3709 the symbol at the specified address.
3713 The standard remote protocol now includes an extension that allows
3714 asynchronous collection and display of trace data. This requires
3715 extensive support in the target-side debugging stub. Tracing mode
3716 includes a new interaction mode in GDB and new commands: see the
3717 file tracepoint.c for more details.
3721 Configurations for embedded MIPS now include a simulator contributed
3722 by Cygnus Solutions. The simulator supports the instruction sets
3723 of most MIPS variants.
3727 Sparc configurations may now include the ERC32 simulator contributed
3728 by the European Space Agency. The simulator is not built into
3729 Sparc targets by default; configure with --enable-sim to include it.
3733 For target configurations that may include multiple variants of a
3734 basic architecture (such as MIPS and SH), you may now set the
3735 architecture explicitly. "set arch" sets, "info arch" lists
3736 the possible architectures.
3738 *** Changes in GDB-4.16:
3740 * New native configurations
3742 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3743 M68K NetBSD m68k-*-netbsd*
3744 PowerPC AIX 4.x powerpc-*-aix*
3745 PowerPC MacOS powerpc-*-macos*
3746 PowerPC Windows NT powerpcle-*-cygwin32
3747 RS/6000 AIX 4.x rs6000-*-aix4*
3751 ARM with RDP protocol arm-*-*
3752 I960 with MON960 i960-*-coff
3753 MIPS VxWorks mips*-*-vxworks*
3754 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3755 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3757 Matra Sparclet sparclet-*-*
3761 The powerpc-eabi configuration now includes the PSIM simulator,
3762 contributed by Andrew Cagney, with assistance from Mike Meissner.
3763 PSIM is a very elaborate model of the PowerPC, including not only
3764 basic instruction set execution, but also details of execution unit
3765 performance and I/O hardware. See sim/ppc/README for more details.
3769 GDB now works with Solaris 2.5.
3771 * Windows 95/NT native
3773 GDB will now work as a native debugger on Windows 95 and Windows NT.
3774 To build it from source, you must use the "gnu-win32" environment,
3775 which uses a DLL to emulate enough of Unix to run the GNU tools.
3776 Further information, binaries, and sources are available at
3777 ftp.cygnus.com, under pub/gnu-win32.
3779 * dont-repeat command
3781 If a user-defined command includes the command `dont-repeat', then the
3782 command will not be repeated if the user just types return. This is
3783 useful if the command is time-consuming to run, so that accidental
3784 extra keystrokes don't run the same command many times.
3786 * Send break instead of ^C
3788 The standard remote protocol now includes an option to send a break
3789 rather than a ^C to the target in order to interrupt it. By default,
3790 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3792 * Remote protocol timeout
3794 The standard remote protocol includes a new variable `remotetimeout'
3795 that allows you to set the number of seconds before GDB gives up trying
3796 to read from the target. The default value is 2.
3798 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3800 By default GDB will automatically keep track of objects as they are
3801 loaded and unloaded by the dynamic linker. By using the command `set
3802 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3803 when shared library events occur, thus allowing you to set breakpoints
3804 in shared libraries which are explicitly loaded by the inferior.
3806 Note this feature does not work on hpux8. On hpux9 you must link
3807 /usr/lib/end.o into your program. This feature should work
3808 automatically on hpux10.
3810 * Irix 5.x hardware watchpoint support
3812 Irix 5 configurations now support the use of hardware watchpoints.
3814 * Mips protocol "SYN garbage limit"
3816 When debugging a Mips target using the `target mips' protocol, you
3817 may set the number of characters that GDB will ignore by setting
3818 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3819 every character. The default value is 1050.
3821 * Recording and replaying remote debug sessions
3823 If you set `remotelogfile' to the name of a file, gdb will write to it
3824 a recording of a remote debug session. This recording may then be
3825 replayed back to gdb using "gdbreplay". See gdbserver/README for
3826 details. This is useful when you have a problem with GDB while doing
3827 remote debugging; you can make a recording of the session and send it
3828 to someone else, who can then recreate the problem.
3830 * Speedups for remote debugging
3832 GDB includes speedups for downloading and stepping MIPS systems using
3833 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3834 and more efficient S-record downloading.
3836 * Memory use reductions and statistics collection
3838 GDB now uses less memory and reports statistics about memory usage.
3839 Try the `maint print statistics' command, for example.
3841 *** Changes in GDB-4.15:
3843 * Psymtabs for XCOFF
3845 The symbol reader for AIX GDB now uses partial symbol tables. This
3846 can greatly improve startup time, especially for large executables.
3848 * Remote targets use caching
3850 Remote targets now use a data cache to speed up communication with the
3851 remote side. The data cache could lead to incorrect results because
3852 it doesn't know about volatile variables, thus making it impossible to
3853 debug targets which use memory mapped I/O devices. `set remotecache
3854 off' turns the the data cache off.
3856 * Remote targets may have threads
3858 The standard remote protocol now includes support for multiple threads
3859 in the target system, using new protocol commands 'H' and 'T'. See
3860 gdb/remote.c for details.
3864 If GDB is configured with `--enable-netrom', then it will include
3865 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3866 acts as though it is a bank of ROM on the target board, but you can
3867 write into it over the network. GDB's support consists only of
3868 support for fast loading into the emulated ROM; to debug, you must use
3869 another protocol, such as standard remote protocol. The usual
3870 sequence is something like
3872 target nrom <netrom-hostname>
3874 target remote <netrom-hostname>:1235
3878 GDB now includes support for the Apple Macintosh, as a host only. It
3879 may be run as either an MPW tool or as a standalone application, and
3880 it can debug through the serial port. All the usual GDB commands are
3881 available, but to the target command, you must supply "serial" as the
3882 device type instead of "/dev/ttyXX". See mpw-README in the main
3883 directory for more information on how to build. The MPW configuration
3884 scripts */mpw-config.in support only a few targets, and only the
3885 mips-idt-ecoff target has been tested.
3889 GDB configuration now uses autoconf. This is not user-visible,
3890 but does simplify configuration and building.
3894 GDB now supports hpux10.
3896 *** Changes in GDB-4.14:
3898 * New native configurations
3900 x86 FreeBSD i[345]86-*-freebsd
3901 x86 NetBSD i[345]86-*-netbsd
3902 NS32k NetBSD ns32k-*-netbsd
3903 Sparc NetBSD sparc-*-netbsd
3907 A29K VxWorks a29k-*-vxworks
3908 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3909 CPU32 EST-300 emulator m68*-*-est*
3910 PowerPC ELF powerpc-*-elf
3913 * Alpha OSF/1 support for procfs
3915 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3916 possible to attach to running processes. As the mounting of the /proc
3917 filesystem is optional on the Alpha, GDB automatically determines
3918 the availability of /proc during startup. This can lead to problems
3919 if /proc is unmounted after GDB has been started.
3921 * Arguments to user-defined commands
3923 User commands may accept up to 10 arguments separated by whitespace.
3924 Arguments are accessed within the user command via $arg0..$arg9. A
3927 print $arg0 + $arg1 + $arg2
3929 To execute the command use:
3932 Defines the command "adder" which prints the sum of its three arguments.
3933 Note the arguments are text substitutions, so they may reference variables,
3934 use complex expressions, or even perform inferior function calls.
3936 * New `if' and `while' commands
3938 This makes it possible to write more sophisticated user-defined
3939 commands. Both commands take a single argument, which is the
3940 expression to evaluate, and must be followed by the commands to
3941 execute, one per line, if the expression is nonzero, the list being
3942 terminated by the word `end'. The `if' command list may include an
3943 `else' word, which causes the following commands to be executed only
3944 if the expression is zero.
3946 * Fortran source language mode
3948 GDB now includes partial support for Fortran 77. It will recognize
3949 Fortran programs and can evaluate a subset of Fortran expressions, but
3950 variables and functions may not be handled correctly. GDB will work
3951 with G77, but does not yet know much about symbols emitted by other
3954 * Better HPUX support
3956 Most debugging facilities now work on dynamic executables for HPPAs
3957 running hpux9 or later. You can attach to running dynamically linked
3958 processes, but by default the dynamic libraries will be read-only, so
3959 for instance you won't be able to put breakpoints in them. To change
3960 that behavior do the following before running the program:
3966 This will cause the libraries to be mapped private and read-write.
3967 To revert to the normal behavior, do this:
3973 You cannot set breakpoints or examine data in the library until after
3974 the library is loaded if the function/data symbols do not have
3977 GDB can now also read debug symbols produced by the HP C compiler on
3978 HPPAs (sorry, no C++, Fortran or 68k support).
3980 * Target byte order now dynamically selectable
3982 You can choose which byte order to use with a target system, via the
3983 commands "set endian big" and "set endian little", and you can see the
3984 current setting by using "show endian". You can also give the command
3985 "set endian auto", in which case GDB will use the byte order
3986 associated with the executable. Currently, only embedded MIPS
3987 configurations support dynamic selection of target byte order.
3989 * New DOS host serial code
3991 This version uses DPMI interrupts to handle buffered I/O, so you
3992 no longer need to run asynctsr when debugging boards connected to
3995 *** Changes in GDB-4.13:
3997 * New "complete" command
3999 This lists all the possible completions for the rest of the line, if it
4000 were to be given as a command itself. This is intended for use by emacs.
4002 * Trailing space optional in prompt
4004 "set prompt" no longer adds a space for you after the prompt you set. This
4005 allows you to set a prompt which ends in a space or one that does not.
4007 * Breakpoint hit counts
4009 "info break" now displays a count of the number of times the breakpoint
4010 has been hit. This is especially useful in conjunction with "ignore"; you
4011 can ignore a large number of breakpoint hits, look at the breakpoint info
4012 to see how many times the breakpoint was hit, then run again, ignoring one
4013 less than that number, and this will get you quickly to the last hit of
4016 * Ability to stop printing at NULL character
4018 "set print null-stop" will cause GDB to stop printing the characters of
4019 an array when the first NULL is encountered. This is useful when large
4020 arrays actually contain only short strings.
4022 * Shared library breakpoints
4024 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4025 breakpoints in shared libraries before the executable is run.
4027 * Hardware watchpoints
4029 There is a new hardware breakpoint for the watch command for sparclite
4030 targets. See gdb/sparclite/hw_breakpoint.note.
4032 Hardware watchpoints are also now supported under GNU/Linux.
4036 Annotations have been added. These are for use with graphical interfaces,
4037 and are still experimental. Currently only gdba.el uses these.
4039 * Improved Irix 5 support
4041 GDB now works properly with Irix 5.2.
4043 * Improved HPPA support
4045 GDB now works properly with the latest GCC and GAS.
4047 * New native configurations
4049 Sequent PTX4 i[34]86-sequent-ptx4
4050 HPPA running OSF/1 hppa*-*-osf*
4051 Atari TT running SVR4 m68*-*-sysv4*
4052 RS/6000 LynxOS rs6000-*-lynxos*
4056 OS/9000 i[34]86-*-os9k
4057 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4060 * Hitachi SH7000 and E7000-PC ICE support
4062 There is now support for communicating with the Hitachi E7000-PC ICE.
4063 This is available automatically when GDB is configured for the SH.
4067 As usual, a variety of small fixes and improvements, both generic
4068 and configuration-specific. See the ChangeLog for more detail.
4070 *** Changes in GDB-4.12:
4072 * Irix 5 is now supported
4076 GDB-4.12 on the HPPA has a number of changes which make it unable
4077 to debug the output from the currently released versions of GCC and
4078 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4079 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4080 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4083 *** Changes in GDB-4.11:
4085 * User visible changes:
4089 The "set remotedebug" option is now consistent between the mips remote
4090 target, remote targets using the gdb-specific protocol, UDI (AMD's
4091 debug protocol for the 29k) and the 88k bug monitor. It is now an
4092 integer specifying a debug level (normally 0 or 1, but 2 means more
4093 debugging info for the mips target).
4095 * DEC Alpha native support
4097 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4098 debug info, but GDB works fairly well with the DEC compiler and should
4099 work with a future GCC release. See the README file for a few
4100 Alpha-specific notes.
4102 * Preliminary thread implementation
4104 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4106 * LynxOS native and target support for 386
4108 This release has been hosted on LynxOS 2.2, and also can be configured
4109 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4112 * Improvements in C++ mangling/demangling.
4114 This release has much better g++ debugging, specifically in name
4115 mangling/demangling, virtual function calls, print virtual table,
4116 call methods, ...etc.
4118 *** Changes in GDB-4.10:
4120 * User visible changes:
4122 Remote debugging using the GDB-specific (`target remote') protocol now
4123 supports the `load' command. This is only useful if you have some
4124 other way of getting the stub to the target system, and you can put it
4125 somewhere in memory where it won't get clobbered by the download.
4127 Filename completion now works.
4129 When run under emacs mode, the "info line" command now causes the
4130 arrow to point to the line specified. Also, "info line" prints
4131 addresses in symbolic form (as well as hex).
4133 All vxworks based targets now support a user settable option, called
4134 vxworks-timeout. This option represents the number of seconds gdb
4135 should wait for responses to rpc's. You might want to use this if
4136 your vxworks target is, perhaps, a slow software simulator or happens
4137 to be on the far side of a thin network line.
4141 This release contains support for using a DEC alpha as a GDB host for
4142 cross debugging. Native alpha debugging is not supported yet.
4145 *** Changes in GDB-4.9:
4149 This is the first GDB release which is accompanied by a matching testsuite.
4150 The testsuite requires installation of dejagnu, which should be available
4151 via ftp from most sites that carry GNU software.
4155 'Cfront' style demangling has had its name changed to 'ARM' style, to
4156 emphasize that it was written from the specifications in the C++ Annotated
4157 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4158 disclaimers, it still generated too much confusion with users attempting to
4159 use gdb with AT&T cfront.
4163 GDB now uses a standard remote interface to a simulator library.
4164 So far, the library contains simulators for the Zilog Z8001/2, the
4165 Hitachi H8/300, H8/500 and Super-H.
4167 * New targets supported
4169 H8/300 simulator h8300-hitachi-hms or h8300hms
4170 H8/500 simulator h8500-hitachi-hms or h8500hms
4171 SH simulator sh-hitachi-hms or sh
4172 Z8000 simulator z8k-zilog-none or z8ksim
4173 IDT MIPS board over serial line mips-idt-ecoff
4175 Cross-debugging to GO32 targets is supported. It requires a custom
4176 version of the i386-stub.c module which is integrated with the
4177 GO32 memory extender.
4179 * New remote protocols
4181 MIPS remote debugging protocol.
4183 * New source languages supported
4185 This version includes preliminary support for Chill, a Pascal like language
4186 used by telecommunications companies. Chill support is also being integrated
4187 into the GNU compiler, but we don't know when it will be publically available.
4190 *** Changes in GDB-4.8:
4192 * HP Precision Architecture supported
4194 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4195 version of this support was available as a set of patches from the
4196 University of Utah. GDB does not support debugging of programs
4197 compiled with the HP compiler, because HP will not document their file
4198 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4199 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4201 Many problems in the preliminary version have been fixed.
4203 * Faster and better demangling
4205 We have improved template demangling and fixed numerous bugs in the GNU style
4206 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4207 character types (wchar_t) are now supported. Demangling of each symbol is now
4208 only done once, and is cached when the symbol table for a file is read in.
4209 This results in a small increase in memory usage for C programs, a moderate
4210 increase in memory usage for C++ programs, and a fantastic speedup in
4213 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4214 from the specifications in the Annotated Reference Manual, which AT&T's
4215 compiler does not actually implement.
4217 * G++ multiple inheritance compiler problem
4219 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4220 inheritance lattices was reworked to properly discover ambiguities. We
4221 recently found an example which causes this new algorithm to fail in a
4222 very subtle way, producing bad debug information for those classes.
4223 The file 'gcc.patch' (in this directory) can be applied to gcc to
4224 circumvent the problem. A future GCC release will contain a complete
4227 The previous G++ debug info problem (mentioned below for the gdb-4.7
4228 release) is fixed in gcc version 2.3.2.
4230 * Improved configure script
4232 The `configure' script will now attempt to guess your system type if
4233 you don't supply a host system type. The old scheme of supplying a
4234 host system triplet is preferable over using this. All the magic is
4235 done in the new `config.guess' script. Examine it for details.
4237 We have also brought our configure script much more in line with the FSF's
4238 version. It now supports the --with-xxx options. In particular,
4239 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4240 The resulting GDB will not be able to read arbitrary object file formats --
4241 only the format ``expected'' to be used on the configured target system.
4242 We hope to make this the default in a future release.
4244 * Documentation improvements
4246 There's new internal documentation on how to modify GDB, and how to
4247 produce clean changes to the code. We implore people to read it
4248 before submitting changes.
4250 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4251 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4252 `info' files are also provided. To build `info' files from scratch,
4253 you will need the latest `makeinfo' release, which will be available in
4254 a future texinfo-X.Y release.
4256 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4257 We're not sure exactly which versions have this problem, but it has
4258 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4259 or better. If that isn't possible, there is a patch in
4260 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4261 around this problem.
4265 GDB now supports array constants that can be used in expressions typed in by
4266 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4267 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4270 The new directory `gdb/sparclite' contains a program that demonstrates
4271 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4273 * New native hosts supported
4275 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4276 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4278 * New targets supported
4280 AMD 29k family via UDI a29k-amd-udi or udi29k
4282 * New file formats supported
4284 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4285 HPUX core files, and SCO 3.2v2 core files.
4289 Attaching to processes now works again; thanks for the many bug reports.
4291 We have also stomped on a bunch of core dumps caused by
4292 printf_filtered("%s") problems.
4294 We eliminated a copyright problem on the rpc and ptrace header files
4295 for VxWorks, which was discovered at the last minute during the 4.7
4296 release. You should now be able to build a VxWorks GDB.
4298 You can now interrupt gdb while an attached process is running. This
4299 will cause the attached process to stop, and give control back to GDB.
4301 We fixed problems caused by using too many file descriptors
4302 for reading symbols from object files and libraries. This was
4303 especially a problem for programs that used many (~100) shared
4306 The `step' command now only enters a subroutine if there is line number
4307 information for the subroutine. Otherwise it acts like the `next'
4308 command. Previously, `step' would enter subroutines if there was
4309 any debugging information about the routine. This avoids problems
4310 when using `cc -g1' on MIPS machines.
4312 * Internal improvements
4314 GDB's internal interfaces have been improved to make it easier to support
4315 debugging of multiple languages in the future.
4317 GDB now uses a common structure for symbol information internally.
4318 Minimal symbols (derived from linkage symbols in object files), partial
4319 symbols (from a quick scan of debug information), and full symbols
4320 contain a common subset of information, making it easier to write
4321 shared code that handles any of them.
4323 * New command line options
4325 We now accept --silent as an alias for --quiet.
4329 The memory-mapped-malloc library is now licensed under the GNU Library
4330 General Public License.
4332 *** Changes in GDB-4.7:
4334 * Host/native/target split
4336 GDB has had some major internal surgery to untangle the support for
4337 hosts and remote targets. Now, when you configure GDB for a remote
4338 target, it will no longer load in all of the support for debugging
4339 local programs on the host. When fully completed and tested, this will
4340 ensure that arbitrary host/target combinations are possible.
4342 The primary conceptual shift is to separate the non-portable code in
4343 GDB into three categories. Host specific code is required any time GDB
4344 is compiled on that host, regardless of the target. Target specific
4345 code relates to the peculiarities of the target, but can be compiled on
4346 any host. Native specific code is everything else: it can only be
4347 built when the host and target are the same system. Child process
4348 handling and core file support are two common `native' examples.
4350 GDB's use of /proc for controlling Unix child processes is now cleaner.
4351 It has been split out into a single module under the `target_ops' vector,
4352 plus two native-dependent functions for each system that uses /proc.
4354 * New hosts supported
4356 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4357 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4358 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4360 * New targets supported
4362 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4363 68030 and CPU32 m68030-*-*, m68332-*-*
4365 * New native hosts supported
4367 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4368 (386bsd is not well tested yet)
4369 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4371 * New file formats supported
4373 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4374 supports reading of `a.out.adobe' object files, which are an a.out
4375 format extended with minimal information about multiple sections.
4379 `show copying' is the same as the old `info copying'.
4380 `show warranty' is the same as `info warrantee'.
4381 These were renamed for consistency. The old commands continue to work.
4383 `info handle' is a new alias for `info signals'.
4385 You can now define pre-command hooks, which attach arbitrary command
4386 scripts to any command. The commands in the hook will be executed
4387 prior to the user's command. You can also create a hook which will be
4388 executed whenever the program stops. See gdb.texinfo.
4392 We now deal with Cfront style name mangling, and can even extract type
4393 info from mangled symbols. GDB can automatically figure out which
4394 symbol mangling style your C++ compiler uses.
4396 Calling of methods and virtual functions has been improved as well.
4400 The crash that occured when debugging Sun Ansi-C compiled binaries is
4401 fixed. This was due to mishandling of the extra N_SO stabs output
4404 We also finally got Ultrix 4.2 running in house, and fixed core file
4405 support, with help from a dozen people on the net.
4407 John M. Farrell discovered that the reason that single-stepping was so
4408 slow on all of the Mips based platforms (primarily SGI and DEC) was
4409 that we were trying to demangle and lookup a symbol used for internal
4410 purposes on every instruction that was being stepped through. Changing
4411 the name of that symbol so that it couldn't be mistaken for a C++
4412 mangled symbol sped things up a great deal.
4414 Rich Pixley sped up symbol lookups in general by getting much smarter
4415 about when C++ symbol mangling is necessary. This should make symbol
4416 completion (TAB on the command line) much faster. It's not as fast as
4417 we'd like, but it's significantly faster than gdb-4.6.
4421 A new user controllable variable 'call_scratch_address' can
4422 specify the location of a scratch area to be used when GDB
4423 calls a function in the target. This is necessary because the
4424 usual method of putting the scratch area on the stack does not work
4425 in systems that have separate instruction and data spaces.
4427 We integrated changes to support the 29k UDI (Universal Debugger
4428 Interface), but discovered at the last minute that we didn't have all
4429 of the appropriate copyright paperwork. We are working with AMD to
4430 resolve this, and hope to have it available soon.
4434 We have sped up the remote serial line protocol, especially for targets
4435 with lots of registers. It now supports a new `expedited status' ('T')
4436 message which can be used in place of the existing 'S' status message.
4437 This allows the remote stub to send only the registers that GDB
4438 needs to make a quick decision about single-stepping or conditional
4439 breakpoints, eliminating the need to fetch the entire register set for
4440 each instruction being stepped through.
4442 The GDB remote serial protocol now implements a write-through cache for
4443 registers, only re-reading the registers if the target has run.
4445 There is also a new remote serial stub for SPARC processors. You can
4446 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4447 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4448 processor with a serial port.
4452 Configure.in files have become much easier to read and modify. A new
4453 `table driven' format makes it more obvious what configurations are
4454 supported, and what files each one uses.
4458 There is a new opcodes library which will eventually contain all of the
4459 disassembly routines and opcode tables. At present, it only contains
4460 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4461 disassembler (binutils/objdump) to share these routines.
4463 The libiberty library is now copylefted under the GNU Library General
4464 Public License. This allows more liberal use, and was done so libg++
4465 can use it. This makes no difference to GDB, since the Library License
4466 grants all the rights from the General Public License.
4470 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4471 reference to the stabs symbol info used by the debugger. It is (as far
4472 as we know) the only published document on this fascinating topic. We
4473 encourage you to read it, compare it to the stabs information on your
4474 system, and send improvements on the document in general (to
4475 bug-gdb@prep.ai.mit.edu).
4477 And, of course, many bugs have been fixed.
4480 *** Changes in GDB-4.6:
4482 * Better support for C++ function names
4484 GDB now accepts as input the "demangled form" of C++ overloaded function
4485 names and member function names, and can do command completion on such names
4486 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4487 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4488 Make use of command completion, it is your friend.
4490 GDB also now accepts a variety of C++ mangled symbol formats. They are
4491 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4492 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4493 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4494 for the list of formats.
4496 * G++ symbol mangling problem
4498 Recent versions of gcc have a bug in how they emit debugging information for
4499 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4500 directory) can be applied to gcc to fix the problem. Alternatively, if you
4501 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4502 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4503 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4506 * New 'maintenance' command
4508 All of the commands related to hacking GDB internals have been moved out of
4509 the main command set, and now live behind the 'maintenance' command. This
4510 can also be abbreviated as 'mt'. The following changes were made:
4512 dump-me -> maintenance dump-me
4513 info all-breakpoints -> maintenance info breakpoints
4514 printmsyms -> maintenance print msyms
4515 printobjfiles -> maintenance print objfiles
4516 printpsyms -> maintenance print psymbols
4517 printsyms -> maintenance print symbols
4519 The following commands are new:
4521 maintenance demangle Call internal GDB demangler routine to
4522 demangle a C++ link name and prints the result.
4523 maintenance print type Print a type chain for a given symbol
4525 * Change to .gdbinit file processing
4527 We now read the $HOME/.gdbinit file before processing the argv arguments
4528 (e.g. reading symbol files or core files). This allows global parameters to
4529 be set, which will apply during the symbol reading. The ./.gdbinit is still
4530 read after argv processing.
4532 * New hosts supported
4534 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4536 GNU/Linux support i386-unknown-linux or linux
4538 We are also including code to support the HP/PA running BSD and HPUX. This
4539 is almost guaranteed not to work, as we didn't have time to test or build it
4540 for this release. We are including it so that the more adventurous (or
4541 masochistic) of you can play with it. We also had major problems with the
4542 fact that the compiler that we got from HP doesn't support the -g option.
4545 * New targets supported
4547 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4549 * More smarts about finding #include files
4551 GDB now remembers the compilation directory for all include files, and for
4552 all files from which C is generated (like yacc and lex sources). This
4553 greatly improves GDB's ability to find yacc/lex sources, and include files,
4554 especially if you are debugging your program from a directory different from
4555 the one that contains your sources.
4557 We also fixed a bug which caused difficulty with listing and setting
4558 breakpoints in include files which contain C code. (In the past, you had to
4559 try twice in order to list an include file that you hadn't looked at before.)
4561 * Interesting infernals change
4563 GDB now deals with arbitrary numbers of sections, where the symbols for each
4564 section must be relocated relative to that section's landing place in the
4565 target's address space. This work was needed to support ELF with embedded
4566 stabs used by Solaris-2.0.
4568 * Bug fixes (of course!)
4570 There have been loads of fixes for the following things:
4571 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4572 i960, stabs, DOS(GO32), procfs, etc...
4574 See the ChangeLog for details.
4576 *** Changes in GDB-4.5:
4578 * New machines supported (host and target)
4580 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4582 SGI Irix-4.x mips-sgi-irix4 or iris4
4584 * New malloc package
4586 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4587 Mmalloc is capable of handling mutiple heaps of memory. It is also
4588 capable of saving a heap to a file, and then mapping it back in later.
4589 This can be used to greatly speedup the startup of GDB by using a
4590 pre-parsed symbol table which lives in a mmalloc managed heap. For
4591 more details, please read mmalloc/mmalloc.texi.
4595 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4596 'help info proc' for details.
4598 * MIPS ecoff symbol table format
4600 The code that reads MIPS symbol table format is now supported on all hosts.
4601 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4604 * File name changes for MS-DOS
4606 Many files in the config directories have been renamed to make it easier to
4607 support GDB on MS-DOSe systems (which have very restrictive file name
4608 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4609 environment) is close to working but has some remaining problems. Note
4610 that debugging of DOS programs is not supported, due to limitations
4611 in the ``operating system'', but it can be used to host cross-debugging.
4613 * Cross byte order fixes
4615 Many fixes have been made to support cross debugging of Sparc and MIPS
4616 targets from hosts whose byte order differs.
4618 * New -mapped and -readnow options
4620 If memory-mapped files are available on your system through the 'mmap'
4621 system call, you can use the -mapped option on the `file' or
4622 `symbol-file' commands to cause GDB to write the symbols from your
4623 program into a reusable file. If the program you are debugging is
4624 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4625 Future GDB debugging sessions will notice the presence of this file,
4626 and will quickly map in symbol information from it, rather than reading
4627 the symbol table from the executable program. Using the '-mapped'
4628 option in a GDB `file' or `symbol-file' command has the same effect as
4629 starting GDB with the '-mapped' command-line option.
4631 You can cause GDB to read the entire symbol table immediately by using
4632 the '-readnow' option with any of the commands that load symbol table
4633 information (or on the GDB command line). This makes the command
4634 slower, but makes future operations faster.
4636 The -mapped and -readnow options are typically combined in order to
4637 build a `fred.syms' file that contains complete symbol information.
4638 A simple GDB invocation to do nothing but build a `.syms' file for future
4641 gdb -batch -nx -mapped -readnow programname
4643 The `.syms' file is specific to the host machine on which GDB is run.
4644 It holds an exact image of GDB's internal symbol table. It cannot be
4645 shared across multiple host platforms.
4647 * longjmp() handling
4649 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4650 siglongjmp() without losing control. This feature has not yet been ported to
4651 all systems. It currently works on many 386 platforms, all MIPS-based
4652 platforms (SGI, DECstation, etc), and Sun3/4.
4656 Preliminary work has been put in to support the new Solaris OS from Sun. At
4657 this time, it can control and debug processes, but it is not capable of
4662 As always, many many bug fixes. The major areas were with g++, and mipsread.
4663 People using the MIPS-based platforms should experience fewer mysterious
4664 crashes and trashed symbol tables.
4666 *** Changes in GDB-4.4:
4668 * New machines supported (host and target)
4670 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4672 BSD Reno on Vax vax-dec-bsd
4673 Ultrix on Vax vax-dec-ultrix
4675 * New machines supported (target)
4677 AMD 29000 embedded, using EBMON a29k-none-none
4681 GDB continues to improve its handling of C++. `References' work better.
4682 The demangler has also been improved, and now deals with symbols mangled as
4683 per the Annotated C++ Reference Guide.
4685 GDB also now handles `stabs' symbol information embedded in MIPS
4686 `ecoff' symbol tables. Since the ecoff format was not easily
4687 extensible to handle new languages such as C++, this appeared to be a
4688 good way to put C++ debugging info into MIPS binaries. This option
4689 will be supported in the GNU C compiler, version 2, when it is
4692 * New features for SVR4
4694 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4695 shared libraries. Debugging dynamically linked programs should present
4696 only minor differences from debugging statically linked programs.
4698 The `info proc' command will print out information about any process
4699 on an SVR4 system (including the one you are debugging). At the moment,
4700 it prints the address mappings of the process.
4702 If you bring up GDB on another SVR4 system, please send mail to
4703 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4705 * Better dynamic linking support in SunOS
4707 Reading symbols from shared libraries which contain debugging symbols
4708 now works properly. However, there remain issues such as automatic
4709 skipping of `transfer vector' code during function calls, which
4710 make it harder to debug code in a shared library, than to debug the
4711 same code linked statically.
4715 GDB is now using the latest `getopt' routines from the FSF. This
4716 version accepts the -- prefix for options with long names. GDB will
4717 continue to accept the old forms (-option and +option) as well.
4718 Various single letter abbreviations for options have been explicity
4719 added to the option table so that they won't get overshadowed in the
4720 future by other options that begin with the same letter.
4724 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4725 Many assorted bugs have been handled. Many more remain to be handled.
4726 See the various ChangeLog files (primarily in gdb and bfd) for details.
4729 *** Changes in GDB-4.3:
4731 * New machines supported (host and target)
4733 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4734 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4735 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4737 * Almost SCO Unix support
4739 We had hoped to support:
4740 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4741 (except for core file support), but we discovered very late in the release
4742 that it has problems with process groups that render gdb unusable. Sorry
4743 about that. I encourage people to fix it and post the fixes.
4745 * Preliminary ELF and DWARF support
4747 GDB can read ELF object files on System V Release 4, and can handle
4748 debugging records for C, in DWARF format, in ELF files. This support
4749 is preliminary. If you bring up GDB on another SVR4 system, please
4750 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4755 GDB now uses the latest `readline' library. One user-visible change
4756 is that two tabs will list possible command completions, which previously
4757 required typing M-? (meta-question mark, or ESC ?).
4761 The `stepi' bug that many of you noticed has been squashed.
4762 Many bugs in C++ have been handled. Many more remain to be handled.
4763 See the various ChangeLog files (primarily in gdb and bfd) for details.
4765 * State of the MIPS world (in case you wondered):
4767 GDB can understand the symbol tables emitted by the compilers
4768 supplied by most vendors of MIPS-based machines, including DEC. These
4769 symbol tables are in a format that essentially nobody else uses.
4771 Some versions of gcc come with an assembler post-processor called
4772 mips-tfile. This program is required if you want to do source-level
4773 debugging of gcc-compiled programs. I believe FSF does not ship
4774 mips-tfile with gcc version 1, but it will eventually come with gcc
4777 Debugging of g++ output remains a problem. g++ version 1.xx does not
4778 really support it at all. (If you're lucky, you should be able to get
4779 line numbers and stack traces to work, but no parameters or local
4780 variables.) With some work it should be possible to improve the
4783 When gcc version 2 is released, you will have somewhat better luck.
4784 However, even then you will get confusing results for inheritance and
4787 We will eventually provide full debugging of g++ output on
4788 DECstations. This will probably involve some kind of stabs-in-ecoff
4789 encapulation, but the details have not been worked out yet.
4792 *** Changes in GDB-4.2:
4794 * Improved configuration
4796 Only one copy of `configure' exists now, and it is not self-modifying.
4797 Porting BFD is simpler.
4801 The `step' and `next' commands now only stop at the first instruction
4802 of a source line. This prevents the multiple stops that used to occur
4803 in switch statements, for-loops, etc. `Step' continues to stop if a
4804 function that has debugging information is called within the line.
4808 Lots of small bugs fixed. More remain.
4810 * New host supported (not target)
4812 Intel 386 PC clone running Mach i386-none-mach
4815 *** Changes in GDB-4.1:
4817 * Multiple source language support
4819 GDB now has internal scaffolding to handle several source languages.
4820 It determines the type of each source file from its filename extension,
4821 and will switch expression parsing and number formatting to match the
4822 language of the function in the currently selected stack frame.
4823 You can also specifically set the language to be used, with
4824 `set language c' or `set language modula-2'.
4828 GDB now has preliminary support for the GNU Modula-2 compiler,
4829 currently under development at the State University of New York at
4830 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4831 continue through the fall of 1991 and into 1992.
4833 Other Modula-2 compilers are currently not supported, and attempting to
4834 debug programs compiled with them will likely result in an error as the
4835 symbol table is read. Feel free to work on it, though!
4837 There are hooks in GDB for strict type checking and range checking,
4838 in the `Modula-2 philosophy', but they do not currently work.
4842 GDB can now write to executable and core files (e.g. patch
4843 a variable's value). You must turn this switch on, specify
4844 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4845 by assigning a new value to a variable. Modifications take
4848 * Automatic SunOS shared library reading
4850 When you run your program, GDB automatically determines where its
4851 shared libraries (if any) have been loaded, and reads their symbols.
4852 The `share' command is no longer needed. This also works when
4853 examining core files.
4857 You can specify the number of lines that the `list' command shows.
4860 * New machines supported (host and target)
4862 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4863 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4864 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4866 * New hosts supported (not targets)
4868 IBM RT/PC: romp-ibm-aix or rtpc
4870 * New targets supported (not hosts)
4872 AMD 29000 embedded with COFF a29k-none-coff
4873 AMD 29000 embedded with a.out a29k-none-aout
4874 Ultracomputer remote kernel debug a29k-nyu-kern
4876 * New remote interfaces
4882 *** Changes in GDB-4.0:
4886 Wide output is wrapped at good places to make the output more readable.
4888 Gdb now supports cross-debugging from a host machine of one type to a
4889 target machine of another type. Communication with the target system
4890 is over serial lines. The ``target'' command handles connecting to the
4891 remote system; the ``load'' command will download a program into the
4892 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4893 also supports debugging of realtime processes running under VxWorks,
4894 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4895 stub on the target system.
4897 New CPUs supported include the AMD 29000 and Intel 960.
4899 GDB now reads object files and symbol tables via a ``binary file''
4900 library, which allows a single copy of GDB to debug programs of multiple
4901 object file types such as a.out and coff.
4903 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4904 refcard.dvi and refcard.ps are available to format it).
4907 * Control-Variable user interface simplified
4909 All variables that control the operation of the debugger can be set
4910 by the ``set'' command, and displayed by the ``show'' command.
4912 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4913 ``Show prompt'' produces the response:
4914 Gdb's prompt is new-gdb=>.
4916 What follows are the NEW set commands. The command ``help set'' will
4917 print a complete list of old and new set commands. ``help set FOO''
4918 will give a longer description of the variable FOO. ``show'' will show
4919 all of the variable descriptions and their current settings.
4921 confirm on/off: Enables warning questions for operations that are
4922 hard to recover from, e.g. rerunning the program while
4923 it is already running. Default is ON.
4925 editing on/off: Enables EMACS style command line editing
4926 of input. Previous lines can be recalled with
4927 control-P, the current line can be edited with control-B,
4928 you can search for commands with control-R, etc.
4931 history filename NAME: NAME is where the gdb command history
4932 will be stored. The default is .gdb_history,
4933 or the value of the environment variable
4936 history size N: The size, in commands, of the command history. The
4937 default is 256, or the value of the environment variable
4940 history save on/off: If this value is set to ON, the history file will
4941 be saved after exiting gdb. If set to OFF, the
4942 file will not be saved. The default is OFF.
4944 history expansion on/off: If this value is set to ON, then csh-like
4945 history expansion will be performed on
4946 command line input. The default is OFF.
4948 radix N: Sets the default radix for input and output. It can be set
4949 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4950 in the current radix, so "set radix 10" is always a no-op.
4952 height N: This integer value is the number of lines on a page. Default
4953 is 24, the current `stty rows'' setting, or the ``li#''
4954 setting from the termcap entry matching the environment
4957 width N: This integer value is the number of characters on a line.
4958 Default is 80, the current `stty cols'' setting, or the ``co#''
4959 setting from the termcap entry matching the environment
4962 Note: ``set screensize'' is obsolete. Use ``set height'' and
4963 ``set width'' instead.
4965 print address on/off: Print memory addresses in various command displays,
4966 such as stack traces and structure values. Gdb looks
4967 more ``symbolic'' if you turn this off; it looks more
4968 ``machine level'' with it on. Default is ON.
4970 print array on/off: Prettyprint arrays. New convenient format! Default
4973 print demangle on/off: Print C++ symbols in "source" form if on,
4976 print asm-demangle on/off: Same, for assembler level printouts
4979 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4982 * Support for Epoch Environment.
4984 The epoch environment is a version of Emacs v18 with windowing. One
4985 new command, ``inspect'', is identical to ``print'', except that if you
4986 are running in the epoch environment, the value is printed in its own
4990 * Support for Shared Libraries
4992 GDB can now debug programs and core files that use SunOS shared libraries.
4993 Symbols from a shared library cannot be referenced
4994 before the shared library has been linked with the program (this
4995 happens after you type ``run'' and before the function main() is entered).
4996 At any time after this linking (including when examining core files
4997 from dynamically linked programs), gdb reads the symbols from each
4998 shared library when you type the ``sharedlibrary'' command.
4999 It can be abbreviated ``share''.
5001 sharedlibrary REGEXP: Load shared object library symbols for files
5002 matching a unix regular expression. No argument
5003 indicates to load symbols for all shared libraries.
5005 info sharedlibrary: Status of loaded shared libraries.
5010 A watchpoint stops execution of a program whenever the value of an
5011 expression changes. Checking for this slows down execution
5012 tremendously whenever you are in the scope of the expression, but is
5013 quite useful for catching tough ``bit-spreader'' or pointer misuse
5014 problems. Some machines such as the 386 have hardware for doing this
5015 more quickly, and future versions of gdb will use this hardware.
5017 watch EXP: Set a watchpoint (breakpoint) for an expression.
5019 info watchpoints: Information about your watchpoints.
5021 delete N: Deletes watchpoint number N (same as breakpoints).
5022 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5023 enable N: Re-enables watchpoint number N (same as breakpoints).
5026 * C++ multiple inheritance
5028 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5031 * C++ exception handling
5033 Gdb now supports limited C++ exception handling. Besides the existing
5034 ability to breakpoint on an exception handler, gdb can breakpoint on
5035 the raising of an exception (before the stack is peeled back to the
5038 catch FOO: If there is a FOO exception handler in the dynamic scope,
5039 set a breakpoint to catch exceptions which may be raised there.
5040 Multiple exceptions (``catch foo bar baz'') may be caught.
5042 info catch: Lists all exceptions which may be caught in the
5043 current stack frame.
5046 * Minor command changes
5048 The command ``call func (arg, arg, ...)'' now acts like the print
5049 command, except it does not print or save a value if the function's result
5050 is void. This is similar to dbx usage.
5052 The ``up'' and ``down'' commands now always print the frame they end up
5053 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5054 frames without printing.
5056 * New directory command
5058 'dir' now adds directories to the FRONT of the source search path.
5059 The path starts off empty. Source files that contain debug information
5060 about the directory in which they were compiled can be found even
5061 with an empty path; Sun CC and GCC include this information. If GDB can't
5062 find your source file in the current directory, type "dir .".
5064 * Configuring GDB for compilation
5066 For normal use, type ``./configure host''. See README or gdb.texinfo
5069 GDB now handles cross debugging. If you are remotely debugging between
5070 two different machines, type ``./configure host -target=targ''.
5071 Host is the machine where GDB will run; targ is the machine
5072 where the program that you are debugging will run.