1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.5
6 * New command line options:
8 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
9 other initialization files, unlike -nx which disables all of them.
13 ** Vectors can be created with gdb.Type.vector.
15 ** Python's atexit.register now works in GDB.
17 * New Python-based convenience functions:
19 ** $_memeq(buf1, buf2, length)
20 ** $_streq(str1, str2)
22 ** $_regex(str, regex)
24 * The 'cd' command now defaults to using '~' (the home directory) if not
27 * The command 'forward-search' can now be abbreviated as 'fo'.
29 * New configure options
31 --enable-libmcheck/--disable-libmcheck
32 By default, development versions are built with -lmcheck on hosts
33 that support it, in order to help track memory corruption issues.
34 Release versions, on the other hand, are built without -lmcheck
35 by default. The --enable-libmcheck/--disable-libmcheck configure
36 options allow the user to override that default.
38 * New commands (for set/show, see "New options" below)
41 List the BFDs known to GDB.
43 python-interactive [command]
45 Start a Python interactive prompt, or evaluate the optional command
46 and print the result of expressions.
49 "py" is a new alias for "python".
53 ** For the Renesas Super-H architecture, the "regs" command has been removed
54 (has been deprecated in GDB 7.5), and "info all-registers" should be used
59 ** Command parameter changes are now notified using new async record
61 ** Trace frame changes caused by command "tfind" are now notified using
62 new async record "=traceframe-changed".
63 ** The creation and deletion of trace state variables are now notified
64 using new async records "=tsv-created" and "=tsv-deleted".
65 ** The start and stop of process record are now notified using new
66 async record "=record-started" and "=record-stopped".
67 ** Memory changes are now notified using new async record
70 *** Changes in GDB 7.5
72 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
73 for more x32 ABI info.
75 * GDB now supports access to MIPS DSP registers on Linux targets.
77 * GDB now supports debugging microMIPS binaries.
79 * The "info os" command on GNU/Linux can now display information on
80 several new classes of objects managed by the operating system:
81 "info os procgroups" lists process groups
82 "info os files" lists file descriptors
83 "info os sockets" lists internet-domain sockets
84 "info os shm" lists shared-memory regions
85 "info os semaphores" lists semaphores
86 "info os msg" lists message queues
87 "info os modules" lists loaded kernel modules
89 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
90 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
91 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
92 options and inspect the probe arguments using the new $_probe_arg family
93 of convenience variables. You can obtain more information about SystemTap
94 in <http://sourceware.org/systemtap/>.
96 * GDB now supports reversible debugging on ARM, it allows you to
97 debug basic ARM and THUMB instructions, and provides
98 record/replay support.
100 * The option "symbol-reloading" has been deleted as it is no longer used.
104 ** GDB commands implemented in Python can now be put in command class
107 ** The "maint set python print-stack on|off" is now deleted.
109 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
110 apply "flag enum"-style pretty-printing to any enum.
112 ** gdb.lookup_symbol can now work when there is no current frame.
114 ** gdb.Symbol now has a 'line' attribute, holding the line number in
115 the source at which the symbol was defined.
117 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
118 method 'value'. The former indicates whether the symbol needs a
119 frame in order to compute its value, and the latter computes the
122 ** A new method 'referenced_value' on gdb.Value objects which can
123 dereference pointer as well as C++ reference values.
125 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
126 which return the global and static blocks (as gdb.Block objects),
127 of the underlying symbol table, respectively.
129 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
130 object associated with a PC value.
132 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
133 of the address range occupied by code for the current source line.
135 * Go language support.
136 GDB now supports debugging programs written in the Go programming
139 * GDBserver now supports stdio connections.
140 E.g. (gdb) target remote | ssh myhost gdbserver - hello
142 * The binary "gdbtui" can no longer be built or installed.
143 Use "gdb -tui" instead.
145 * GDB will now print "flag" enums specially. A flag enum is one where
146 all the enumerator values have no bits in common when pairwise
147 "and"ed. When printing a value whose type is a flag enum, GDB will
148 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
149 (gdb) print (enum E) 3
152 * The filename part of a linespec will now match trailing components
153 of a source file name. For example, "break gcc/expr.c:1000" will
154 now set a breakpoint in build/gcc/expr.c, but not
157 * The "info proc" and "generate-core-file" commands will now also
158 work on remote targets connected to GDBserver on Linux.
160 * The command "info catch" has been removed. It has been disabled
163 * The "catch exception" and "catch assert" commands now accept
164 a condition at the end of the command, much like the "break"
165 command does. For instance:
167 (gdb) catch exception Constraint_Error if Barrier = True
169 Previously, it was possible to add a condition to such catchpoints,
170 but it had to be done as a second step, after the catchpoint had been
171 created, using the "condition" command.
173 * The "info static-tracepoint-marker" command will now also work on
174 native Linux targets with in-process agent.
176 * GDB can now set breakpoints on inlined functions.
178 * The .gdb_index section has been updated to include symbols for
179 inlined functions. GDB will ignore older .gdb_index sections by
180 default, which could cause symbol files to be loaded more slowly
181 until their .gdb_index sections can be recreated. The new command
182 "set use-deprecated-index-sections on" will cause GDB to use any older
183 .gdb_index sections it finds. This will restore performance, but the
184 ability to set breakpoints on inlined functions will be lost in symbol
185 files with older .gdb_index sections.
187 The .gdb_index section has also been updated to record more information
188 about each symbol. This speeds up the "info variables", "info functions"
189 and "info types" commands when used with programs having the .gdb_index
190 section, as well as speeding up debugging with shared libraries using
191 the .gdb_index section.
193 * Ada support for GDB/MI Variable Objects has been added.
195 * GDB can now support 'breakpoint always-inserted mode' in 'record'
200 ** New command -info-os is the MI equivalent of "info os".
202 ** Output logs ("set logging" and related) now include MI output.
206 ** "set use-deprecated-index-sections on|off"
207 "show use-deprecated-index-sections on|off"
208 Controls the use of deprecated .gdb_index sections.
210 ** "catch load" and "catch unload" can be used to stop when a shared
211 library is loaded or unloaded, respectively.
213 ** "enable count" can be used to auto-disable a breakpoint after
216 ** "info vtbl" can be used to show the virtual method tables for
217 C++ and Java objects.
219 ** "explore" and its sub commands "explore value" and "explore type"
220 can be used to reccursively explore values and types of
221 expressions. These commands are available only if GDB is
222 configured with '--with-python'.
224 ** "info auto-load" shows status of all kinds of auto-loaded files,
225 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
226 sequences of commands files, "info auto-load python-scripts"
227 shows status of auto-loading Python script files,
228 "info auto-load local-gdbinit" shows status of loading init file
229 (.gdbinit) from current directory and "info auto-load libthread-db" shows
230 status of inferior specific thread debugging shared library loading.
232 ** "info auto-load-scripts", "set auto-load-scripts on|off"
233 and "show auto-load-scripts" commands have been deprecated, use their
234 "info auto-load python-scripts", "set auto-load python-scripts on|off"
235 and "show auto-load python-scripts" counterparts instead.
237 ** "dprintf location,format,args..." creates a dynamic printf, which
238 is basically a breakpoint that does a printf and immediately
239 resumes your program's execution, so it is like a printf that you
240 can insert dynamically at runtime instead of at compiletime.
242 ** "set print symbol"
244 Controls whether GDB attempts to display the symbol, if any,
245 corresponding to addresses it prints. This defaults to "on", but
246 you can set it to "off" to restore GDB's previous behavior.
248 * Deprecated commands
250 ** For the Renesas Super-H architecture, the "regs" command has been
251 deprecated, and "info all-registers" should be used instead.
255 Renesas RL78 rl78-*-elf
256 HP OpenVMS ia64 ia64-hp-openvms*
258 * GDBserver supports evaluation of breakpoint conditions. When
259 support is advertised by GDBserver, GDB may be told to send the
260 breakpoint conditions in bytecode form to GDBserver. GDBserver
261 will only report the breakpoint trigger to GDB when its condition
267 show mips compression
268 Select the compressed ISA encoding used in functions that have no symbol
269 information available. The encoding can be set to either of:
272 and is updated automatically from ELF file flags if available.
274 set breakpoint condition-evaluation
275 show breakpoint condition-evaluation
276 Control whether breakpoint conditions are evaluated by GDB ("host") or by
277 GDBserver ("target"). Default option "auto" chooses the most efficient
279 This option can improve debugger efficiency depending on the speed of the
283 Disable auto-loading globally.
286 Show auto-loading setting of all kinds of auto-loaded files.
288 set auto-load gdb-scripts on|off
289 show auto-load gdb-scripts
290 Control auto-loading of GDB canned sequences of commands files.
292 set auto-load python-scripts on|off
293 show auto-load python-scripts
294 Control auto-loading of Python script files.
296 set auto-load local-gdbinit on|off
297 show auto-load local-gdbinit
298 Control loading of init file (.gdbinit) from current directory.
300 set auto-load libthread-db on|off
301 show auto-load libthread-db
302 Control auto-loading of inferior specific thread debugging shared library.
304 set auto-load scripts-directory <dir1>[:<dir2>...]
305 show auto-load scripts-directory
306 Set a list of directories from which to load auto-loaded scripts.
307 Automatically loaded Python scripts and GDB scripts are located in one
308 of the directories listed by this option.
309 The delimiter (':' above) may differ according to the host platform.
311 set auto-load safe-path <dir1>[:<dir2>...]
312 show auto-load safe-path
313 Set a list of directories from which it is safe to auto-load files.
314 The delimiter (':' above) may differ according to the host platform.
316 set debug auto-load on|off
318 Control display of debugging info for auto-loading the files above.
320 set dprintf-style gdb|call|agent
322 Control the way in which a dynamic printf is performed; "gdb"
323 requests a GDB printf command, while "call" causes dprintf to call a
324 function in the inferior. "agent" requests that the target agent
325 (such as GDBserver) do the printing.
327 set dprintf-function <expr>
328 show dprintf-function
329 set dprintf-channel <expr>
331 Set the function and optional first argument to the call when using
332 the "call" style of dynamic printf.
334 set disconnected-dprintf on|off
335 show disconnected-dprintf
336 Control whether agent-style dynamic printfs continue to be in effect
337 after GDB disconnects.
339 * New configure options
342 Configure default value for the 'set auto-load scripts-directory'
343 setting above. It defaults to '$debugdir:$datadir/auto-load',
344 $debugdir representing global debugging info directories (available
345 via 'show debug-file-directory') and $datadir representing GDB's data
346 directory (available via 'show data-directory').
348 --with-auto-load-safe-path
349 Configure default value for the 'set auto-load safe-path' setting
350 above. It defaults to the --with-auto-load-dir setting.
352 --without-auto-load-safe-path
353 Set 'set auto-load safe-path' to '/', effectively disabling this
358 z0/z1 conditional breakpoints extension
360 The z0/z1 breakpoint insertion packets have been extended to carry
361 a list of conditional expressions over to the remote stub depending on the
362 condition evaluation mode. The use of this extension can be controlled
363 via the "set remote conditional-breakpoints-packet" command.
367 Specify the signals which the remote stub may pass to the debugged
368 program without GDB involvement.
370 * New command line options
372 --init-command=FILE, -ix Like --command, -x but execute it
373 before loading inferior.
374 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
375 execute it before loading inferior.
377 *** Changes in GDB 7.4
379 * GDB now handles ambiguous linespecs more consistently; the existing
380 FILE:LINE support has been expanded to other types of linespecs. A
381 breakpoint will now be set on all matching locations in all
382 inferiors, and locations will be added or removed according to
385 * GDB now allows you to skip uninteresting functions and files when
386 stepping with the "skip function" and "skip file" commands.
388 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
389 and "show remote hardware-watchpoint-length-limit". These allows to
390 set or show the maximum length limit (in bytes) of a remote
391 target hardware watchpoint.
393 This allows e.g. to use "unlimited" hardware watchpoints with the
394 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
395 watchpoints are slower than real hardware watchpoints but are
396 significantly faster than gdb software watchpoints.
400 ** The register_pretty_printer function in module gdb.printing now takes
401 an optional `replace' argument. If True, the new printer replaces any
404 ** The "maint set python print-stack on|off" command has been
405 deprecated and will be deleted in GDB 7.5.
406 A new command: "set python print-stack none|full|message" has
407 replaced it. Additionally, the default for "print-stack" is
408 now "message", which just prints the error message without
411 ** A prompt substitution hook (prompt_hook) is now available to the
414 ** A new Python module, gdb.prompt has been added to the GDB Python
415 modules library. This module provides functionality for
416 escape sequences in prompts (used by set/show
417 extended-prompt). These escape sequences are replaced by their
420 ** Python commands and convenience-functions located in
421 'data-directory'/python/gdb/command and
422 'data-directory'/python/gdb/function are now automatically loaded
425 ** Blocks now provide four new attributes. global_block and
426 static_block will return the global and static blocks
427 respectively. is_static and is_global are boolean attributes
428 that indicate if the block is one of those two types.
430 ** Symbols now provide the "type" attribute, the type of the symbol.
432 ** The "gdb.breakpoint" function has been deprecated in favor of
435 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
436 of a function. This class is based on the "finish" command
437 available in the CLI.
439 ** Type objects for struct and union types now allow access to
440 the fields using standard Python dictionary (mapping) methods.
441 For example, "some_type['myfield']" now works, as does
444 ** A new event "gdb.new_objfile" has been added, triggered by loading a
447 ** A new function, "deep_items" has been added to the gdb.types
448 module in the GDB Python modules library. This function returns
449 an iterator over the fields of a struct or union type. Unlike
450 the standard Python "iteritems" method, it will recursively traverse
451 any anonymous fields.
455 ** "*stopped" events can report several new "reason"s, such as
458 ** Breakpoint changes are now notified using new async records, like
459 "=breakpoint-modified".
461 ** New command -ada-task-info.
463 * libthread-db-search-path now supports two special values: $sdir and $pdir.
464 $sdir specifies the default system locations of shared libraries.
465 $pdir specifies the directory where the libpthread used by the application
468 GDB no longer looks in $sdir and $pdir after it has searched the directories
469 mentioned in libthread-db-search-path. If you want to search those
470 directories, they must be specified in libthread-db-search-path.
471 The default value of libthread-db-search-path on GNU/Linux and Solaris
472 systems is now "$sdir:$pdir".
474 $pdir is not supported by gdbserver, it is currently ignored.
475 $sdir is supported by gdbserver.
477 * New configure option --with-iconv-bin.
478 When using the internationalization support like the one in the GNU C
479 library, GDB will invoke the "iconv" program to get a list of supported
480 character sets. If this program lives in a non-standard location, one can
481 use this option to specify where to find it.
483 * When natively debugging programs on PowerPC BookE processors running
484 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
485 watchpoints, which specify a mask in addition to an address to watch.
486 The mask specifies that some bits of an address (the bits which are
487 reset in the mask) should be ignored when matching the address accessed
488 by the inferior against the watchpoint address. See the "PowerPC Embedded"
489 section in the user manual for more details.
491 * The new option --once causes GDBserver to stop listening for connections once
492 the first connection is made. The listening port used by GDBserver will
493 become available after that.
495 * New commands "info macros" and "alias" have been added.
497 * New function parameters suffix @entry specifies value of function parameter
498 at the time the function got called. Entry values are available only since
504 "!" is now an alias of the "shell" command.
505 Note that no space is needed between "!" and SHELL COMMAND.
509 watch EXPRESSION mask MASK_VALUE
510 The watch command now supports the mask argument which allows creation
511 of masked watchpoints, if the current architecture supports this feature.
513 info auto-load-scripts [REGEXP]
514 This command was formerly named "maintenance print section-scripts".
515 It is now generally useful and is no longer a maintenance-only command.
517 info macro [-all] [--] MACRO
518 The info macro command has new options `-all' and `--'. The first for
519 printing all definitions of a macro. The second for explicitly specifying
520 the end of arguments and the beginning of the macro name in case the macro
521 name starts with a hyphen.
523 collect[/s] EXPRESSIONS
524 The tracepoint collect command now takes an optional modifier "/s"
525 that directs it to dereference pointer-to-character types and
526 collect the bytes of memory up to a zero byte. The behavior is
527 similar to what you see when you use the regular print command on a
528 string. An optional integer following the "/s" sets a bound on the
529 number of bytes that will be collected.
532 The trace start command now interprets any supplied arguments as a
533 note to be recorded with the trace run, with an effect similar to
534 setting the variable trace-notes.
537 The trace stop command now interprets any arguments as a note to be
538 mentioned along with the tstatus report that the trace was stopped
539 with a command. The effect is similar to setting the variable
542 * Tracepoints can now be enabled and disabled at any time after a trace
543 experiment has been started using the standard "enable" and "disable"
544 commands. It is now possible to start a trace experiment with no enabled
545 tracepoints; GDB will display a warning, but will allow the experiment to
546 begin, assuming that tracepoints will be enabled as needed while the trace
549 * Fast tracepoints on 32-bit x86-architectures can now be placed at
550 locations with 4-byte instructions, when they were previously
551 limited to locations with instructions of 5 bytes or longer.
555 set debug dwarf2-read
556 show debug dwarf2-read
557 Turns on or off display of debugging messages related to reading
558 DWARF debug info. The default is off.
560 set debug symtab-create
561 show debug symtab-create
562 Turns on or off display of debugging messages related to symbol table
563 creation. The default is off.
567 Set the GDB prompt, and allow escape sequences to be inserted to
568 display miscellaneous information (see 'help set extended-prompt'
569 for the list of sequences). This prompt (and any information
570 accessed through the escape sequences) is updated every time the
573 set print entry-values (both|compact|default|if-needed|no|only|preferred)
574 show print entry-values
575 Set printing of frame argument values at function entry. In some cases
576 GDB can determine the value of function argument which was passed by the
577 function caller, even if the value was modified inside the called function.
579 set debug entry-values
580 show debug entry-values
581 Control display of debugging info for determining frame argument values at
582 function entry and virtual tail call frames.
584 set basenames-may-differ
585 show basenames-may-differ
586 Set whether a source file may have multiple base names.
587 (A "base name" is the name of a file with the directory part removed.
588 Example: The base name of "/home/user/hello.c" is "hello.c".)
589 If set, GDB will canonicalize file names (e.g., expand symlinks)
590 before comparing them. Canonicalization is an expensive operation,
591 but it allows the same file be known by more than one base name.
592 If not set (the default), all source files are assumed to have just
593 one base name, and gdb will do file name comparisons more efficiently.
599 Set a user name and notes for the current and any future trace runs.
600 This is useful for long-running and/or disconnected traces, to
601 inform others (or yourself) as to who is running the trace, supply
602 contact information, or otherwise explain what is going on.
605 show trace-stop-notes
606 Set a note attached to the trace run, that is displayed when the
607 trace has been stopped by a tstop command. This is useful for
608 instance as an explanation, if you are stopping a trace run that was
609 started by someone else.
615 Dynamically enable a tracepoint in a started trace experiment.
619 Dynamically disable a tracepoint in a started trace experiment.
623 Set the user and notes of the trace run.
627 Query the current status of a tracepoint.
631 Query the minimum length of instruction at which a fast tracepoint may
634 * Dcache size (number of lines) and line-size are now runtime-configurable
635 via "set dcache line" and "set dcache line-size" commands.
639 Texas Instruments TMS320C6x tic6x-*-*
643 Renesas RL78 rl78-*-elf
645 *** Changes in GDB 7.3.1
647 * The build failure for NetBSD and OpenBSD targets have now been fixed.
649 *** Changes in GDB 7.3
651 * GDB has a new command: "thread find [REGEXP]".
652 It finds the thread id whose name, target id, or thread extra info
653 matches the given regular expression.
655 * The "catch syscall" command now works on mips*-linux* targets.
657 * The -data-disassemble MI command now supports modes 2 and 3 for
658 dumping the instruction opcodes.
660 * New command line options
662 -data-directory DIR Specify DIR as the "data-directory".
663 This is mostly for testing purposes.
665 * The "maint set python auto-load on|off" command has been renamed to
666 "set auto-load-scripts on|off".
668 * GDB has a new command: "set directories".
669 It is like the "dir" command except that it replaces the
670 source path list instead of augmenting it.
672 * GDB now understands thread names.
674 On GNU/Linux, "info threads" will display the thread name as set by
675 prctl or pthread_setname_np.
677 There is also a new command, "thread name", which can be used to
678 assign a name internally for GDB to display.
681 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
682 has been integrated into GDB.
686 ** The function gdb.Write now accepts an optional keyword 'stream'.
687 This keyword, when provided, will direct the output to either
688 stdout, stderr, or GDB's logging output.
690 ** Parameters can now be be sub-classed in Python, and in particular
691 you may implement the get_set_doc and get_show_doc functions.
692 This improves how Parameter set/show documentation is processed
693 and allows for more dynamic content.
695 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
696 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
697 have an is_valid method.
699 ** Breakpoints can now be sub-classed in Python, and in particular
700 you may implement a 'stop' function that is executed each time
701 the inferior reaches that breakpoint.
703 ** New function gdb.lookup_global_symbol looks up a global symbol.
705 ** GDB values in Python are now callable if the value represents a
706 function. For example, if 'some_value' represents a function that
707 takes two integer parameters and returns a value, you can call
708 that function like so:
710 result = some_value (10,20)
712 ** Module gdb.types has been added.
713 It contains a collection of utilities for working with gdb.Types objects:
714 get_basic_type, has_field, make_enum_dict.
716 ** Module gdb.printing has been added.
717 It contains utilities for writing and registering pretty-printers.
718 New classes: PrettyPrinter, SubPrettyPrinter,
719 RegexpCollectionPrettyPrinter.
720 New function: register_pretty_printer.
722 ** New commands "info pretty-printers", "enable pretty-printer" and
723 "disable pretty-printer" have been added.
725 ** gdb.parameter("directories") is now available.
727 ** New function gdb.newest_frame returns the newest frame in the
730 ** The gdb.InferiorThread class has a new "name" attribute. This
731 holds the thread's name.
733 ** Python Support for Inferior events.
734 Python scripts can add observers to be notified of events
735 occurring in the process being debugged.
736 The following events are currently supported:
737 - gdb.events.cont Continue event.
738 - gdb.events.exited Inferior exited event.
739 - gdb.events.stop Signal received, and Breakpoint hit events.
743 ** GDB now puts template parameters in scope when debugging in an
744 instantiation. For example, if you have:
746 template<int X> int func (void) { return X; }
748 then if you step into func<5>, "print X" will show "5". This
749 feature requires proper debuginfo support from the compiler; it
750 was added to GCC 4.5.
752 ** The motion commands "next", "finish", "until", and "advance" now
753 work better when exceptions are thrown. In particular, GDB will
754 no longer lose control of the inferior; instead, the GDB will
755 stop the inferior at the point at which the exception is caught.
756 This functionality requires a change in the exception handling
757 code that was introduced in GCC 4.5.
759 * GDB now follows GCC's rules on accessing volatile objects when
760 reading or writing target state during expression evaluation.
761 One notable difference to prior behavior is that "print x = 0"
762 no longer generates a read of x; the value of the assignment is
763 now always taken directly from the value being assigned.
765 * GDB now has some support for using labels in the program's source in
766 linespecs. For instance, you can use "advance label" to continue
767 execution to a label.
769 * GDB now has support for reading and writing a new .gdb_index
770 section. This section holds a fast index of DWARF debugging
771 information and can be used to greatly speed up GDB startup and
772 operation. See the documentation for `save gdb-index' for details.
774 * The "watch" command now accepts an optional "-location" argument.
775 When used, this causes GDB to watch the memory referred to by the
776 expression. Such a watchpoint is never deleted due to it going out
779 * GDB now supports thread debugging of core dumps on GNU/Linux.
781 GDB now activates thread debugging using the libthread_db library
782 when debugging GNU/Linux core dumps, similarly to when debugging
783 live processes. As a result, when debugging a core dump file, GDB
784 is now able to display pthread_t ids of threads. For example, "info
785 threads" shows the same output as when debugging the process when it
786 was live. In earlier releases, you'd see something like this:
789 * 1 LWP 6780 main () at main.c:10
791 While now you see this:
794 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
796 It is also now possible to inspect TLS variables when debugging core
799 When debugging a core dump generated on a machine other than the one
800 used to run GDB, you may need to point GDB at the correct
801 libthread_db library with the "set libthread-db-search-path"
802 command. See the user manual for more details on this command.
804 * When natively debugging programs on PowerPC BookE processors running
805 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
806 which stop execution of the inferior whenever it executes an instruction
807 at any address within the specified range. See the "PowerPC Embedded"
808 section in the user manual for more details.
810 * New features in the GDB remote stub, GDBserver
812 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
813 and i686 LynxOS (version 5.x).
815 ** GDBserver is now supported on Blackfin Linux.
817 * New native configurations
819 ia64 HP-UX ia64-*-hpux*
823 Analog Devices, Inc. Blackfin Processor bfin-*
825 * Ada task switching is now supported on sparc-elf targets when
826 debugging a program using the Ravenscar Profile. For more information,
827 see the "Tasking Support when using the Ravenscar Profile" section
828 in the GDB user manual.
830 * Guile support was removed.
832 * New features in the GNU simulator
834 ** The --map-info flag lists all known core mappings.
836 ** CFI flashes may be simulated via the "cfi" device.
838 *** Changes in GDB 7.2
840 * Shared library support for remote targets by default
842 When GDB is configured for a generic, non-OS specific target, like
843 for example, --target=arm-eabi or one of the many *-*-elf targets,
844 GDB now queries remote stubs for loaded shared libraries using the
845 `qXfer:libraries:read' packet. Previously, shared library support
846 was always disabled for such configurations.
850 ** Argument Dependent Lookup (ADL)
852 In C++ ADL lookup directs function search to the namespaces of its
853 arguments even if the namespace has not been imported.
863 Here the compiler will search for `foo' in the namespace of 'b'
864 and find A::foo. GDB now supports this. This construct is commonly
865 used in the Standard Template Library for operators.
867 ** Improved User Defined Operator Support
869 In addition to member operators, GDB now supports lookup of operators
870 defined in a namespace and imported with a `using' directive, operators
871 defined in the global scope, operators imported implicitly from an
872 anonymous namespace, and the ADL operators mentioned in the previous
874 GDB now also supports proper overload resolution for all the previously
875 mentioned flavors of operators.
877 ** static const class members
879 Printing of static const class members that are initialized in the
880 class definition has been fixed.
882 * Windows Thread Information Block access.
884 On Windows targets, GDB now supports displaying the Windows Thread
885 Information Block (TIB) structure. This structure is visible either
886 by using the new command `info w32 thread-information-block' or, by
887 dereferencing the new convenience variable named `$_tlb', a
888 thread-specific pointer to the TIB. This feature is also supported
889 when remote debugging using GDBserver.
893 Static tracepoints are calls in the user program into a tracing
894 library. One such library is a port of the LTTng kernel tracer to
895 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
896 When debugging with GDBserver, GDB now supports combining the GDB
897 tracepoint machinery with such libraries. For example: the user can
898 use GDB to probe a static tracepoint marker (a call from the user
899 program into the tracing library) with the new "strace" command (see
900 "New commands" below). This creates a "static tracepoint" in the
901 breakpoint list, that can be manipulated with the same feature set
902 as fast and regular tracepoints. E.g., collect registers, local and
903 global variables, collect trace state variables, and define
904 tracepoint conditions. In addition, the user can collect extra
905 static tracepoint marker specific data, by collecting the new
906 $_sdata internal variable. When analyzing the trace buffer, you can
907 inspect $_sdata like any other variable available to GDB. For more
908 information, see the "Tracepoints" chapter in GDB user manual. New
909 remote packets have been defined to support static tracepoints, see
910 the "New remote packets" section below.
912 * Better reconstruction of tracepoints after disconnected tracing
914 GDB will attempt to download the original source form of tracepoint
915 definitions when starting a trace run, and then will upload these
916 upon reconnection to the target, resulting in a more accurate
917 reconstruction of the tracepoints that are in use on the target.
921 You can now exercise direct control over the ways that GDB can
922 affect your program. For instance, you can disallow the setting of
923 breakpoints, so that the program can run continuously (assuming
924 non-stop mode). In addition, the "observer" variable is available
925 to switch all of the different controls; in observer mode, GDB
926 cannot affect the target's behavior at all, which is useful for
927 tasks like diagnosing live systems in the field.
929 * The new convenience variable $_thread holds the number of the
936 Return the address of the Windows Thread Information Block of a given thread.
940 In response to several of the tracepoint packets, the target may now
941 also respond with a number of intermediate `qRelocInsn' request
942 packets before the final result packet, to have GDB handle
943 relocating an instruction to execute at a different address. This
944 is particularly useful for stubs that support fast tracepoints. GDB
945 reports support for this feature in the qSupported packet.
949 List static tracepoint markers in the target program.
953 List static tracepoint markers at a given address in the target
956 qXfer:statictrace:read
958 Read the static trace data collected (by a `collect $_sdata'
959 tracepoint action). The remote stub reports support for this packet
960 to gdb's qSupported query.
964 Send the current settings of GDB's permission flags.
968 Send part of the source (textual) form of a tracepoint definition,
969 which includes location, conditional, and action list.
971 * The source command now accepts a -s option to force searching for the
972 script in the source search path even if the script name specifies
975 * New features in the GDB remote stub, GDBserver
977 - GDBserver now support tracepoints (including fast tracepoints, and
978 static tracepoints). The feature is currently supported by the
979 i386-linux and amd64-linux builds. See the "Tracepoints support
980 in gdbserver" section in the manual for more information.
982 GDBserver JIT compiles the tracepoint's conditional agent
983 expression bytecode into native code whenever possible for low
984 overhead dynamic tracepoints conditionals. For such tracepoints,
985 an expression that examines program state is evaluated when the
986 tracepoint is reached, in order to determine whether to capture
987 trace data. If the condition is simple and false, processing the
988 tracepoint finishes very quickly and no data is gathered.
990 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
991 for static tracepoints support.
993 - GDBserver now supports x86_64 Windows 64-bit debugging.
995 * GDB now sends xmlRegisters= in qSupported packet to indicate that
996 it understands register description.
998 * The --batch flag now disables pagination and queries.
1000 * X86 general purpose registers
1002 GDB now supports reading/writing byte, word and double-word x86
1003 general purpose registers directly. This means you can use, say,
1004 $ah or $ax to refer, respectively, to the byte register AH and
1005 16-bit word register AX that are actually portions of the 32-bit
1006 register EAX or 64-bit register RAX.
1008 * The `commands' command now accepts a range of breakpoints to modify.
1009 A plain `commands' following a command that creates multiple
1010 breakpoints affects all the breakpoints set by that command. This
1011 applies to breakpoints set by `rbreak', and also applies when a
1012 single `break' command creates multiple breakpoints (e.g.,
1013 breakpoints on overloaded c++ functions).
1015 * The `rbreak' command now accepts a filename specification as part of
1016 its argument, limiting the functions selected by the regex to those
1017 in the specified file.
1019 * Support for remote debugging Windows and SymbianOS shared libraries
1020 from Unix hosts has been improved. Non Windows GDB builds now can
1021 understand target reported file names that follow MS-DOS based file
1022 system semantics, such as file names that include drive letters and
1023 use the backslash character as directory separator. This makes it
1024 possible to transparently use the "set sysroot" and "set
1025 solib-search-path" on Unix hosts to point as host copies of the
1026 target's shared libraries. See the new command "set
1027 target-file-system-kind" described below, and the "Commands to
1028 specify files" section in the user manual for more information.
1032 eval template, expressions...
1033 Convert the values of one or more expressions under the control
1034 of the string template to a command line, and call it.
1036 set target-file-system-kind unix|dos-based|auto
1037 show target-file-system-kind
1038 Set or show the assumed file system kind for target reported file
1041 save breakpoints <filename>
1042 Save all current breakpoint definitions to a file suitable for use
1043 in a later debugging session. To read the saved breakpoint
1044 definitions, use the `source' command.
1046 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1049 info static-tracepoint-markers
1050 Display information about static tracepoint markers in the target.
1052 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1053 Define a static tracepoint by probing a marker at the given
1054 function, line, address, or marker ID.
1058 Enable and disable observer mode.
1060 set may-write-registers on|off
1061 set may-write-memory on|off
1062 set may-insert-breakpoints on|off
1063 set may-insert-tracepoints on|off
1064 set may-insert-fast-tracepoints on|off
1065 set may-interrupt on|off
1066 Set individual permissions for GDB effects on the target. Note that
1067 some of these settings can have undesirable or surprising
1068 consequences, particularly when changed in the middle of a session.
1069 For instance, disabling the writing of memory can prevent
1070 breakpoints from being inserted, cause single-stepping to fail, or
1071 even crash your program, if you disable after breakpoints have been
1072 inserted. However, GDB should not crash.
1074 set record memory-query on|off
1075 show record memory-query
1076 Control whether to stop the inferior if memory changes caused
1077 by an instruction cannot be recorded.
1082 The disassemble command now supports "start,+length" form of two arguments.
1086 ** GDB now provides a new directory location, called the python directory,
1087 where Python scripts written for GDB can be installed. The location
1088 of that directory is <data-directory>/python, where <data-directory>
1089 is the GDB data directory. For more details, see section `Scripting
1090 GDB using Python' in the manual.
1092 ** The GDB Python API now has access to breakpoints, symbols, symbol
1093 tables, program spaces, inferiors, threads and frame's code blocks.
1094 Additionally, GDB Parameters can now be created from the API, and
1095 manipulated via set/show in the CLI.
1097 ** New functions gdb.target_charset, gdb.target_wide_charset,
1098 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1100 ** New exception gdb.GdbError.
1102 ** Pretty-printers are now also looked up in the current program space.
1104 ** Pretty-printers can now be individually enabled and disabled.
1106 ** GDB now looks for names of Python scripts to auto-load in a
1107 special section named `.debug_gdb_scripts', in addition to looking
1108 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1110 * Tracepoint actions were unified with breakpoint commands. In particular,
1111 there are no longer differences in "info break" output for breakpoints and
1112 tracepoints and the "commands" command can be used for both tracepoints and
1113 regular breakpoints.
1117 ARM Symbian arm*-*-symbianelf*
1119 * D language support.
1120 GDB now supports debugging programs written in the D programming
1123 * GDB now supports the extended ptrace interface for PowerPC which is
1124 available since Linux kernel version 2.6.34. This automatically enables
1125 any hardware breakpoints and additional hardware watchpoints available in
1126 the processor. The old ptrace interface exposes just one hardware
1127 watchpoint and no hardware breakpoints.
1129 * GDB is now able to use the Data Value Compare (DVC) register available on
1130 embedded PowerPC processors to implement in hardware simple watchpoint
1131 conditions of the form:
1133 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1135 This works in native GDB running on Linux kernels with the extended ptrace
1136 interface mentioned above.
1138 *** Changes in GDB 7.1
1142 ** Namespace Support
1144 GDB now supports importing of namespaces in C++. This enables the
1145 user to inspect variables from imported namespaces. Support for
1146 namepace aliasing has also been added. So, if a namespace is
1147 aliased in the current scope (e.g. namepace C=A; ) the user can
1148 print variables using the alias (e.g. (gdb) print C::x).
1152 All known bugs relating to the printing of virtual base class were
1153 fixed. It is now possible to call overloaded static methods using a
1158 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1159 and reinterpret_cast<> are now handled by the C++ expression parser.
1163 Xilinx MicroBlaze microblaze-*-*
1168 Xilinx MicroBlaze microblaze
1171 * Multi-program debugging.
1173 GDB now has support for multi-program (a.k.a. multi-executable or
1174 multi-exec) debugging. This allows for debugging multiple inferiors
1175 simultaneously each running a different program under the same GDB
1176 session. See "Debugging Multiple Inferiors and Programs" in the
1177 manual for more information. This implied some user visible changes
1178 in the multi-inferior support. For example, "info inferiors" now
1179 lists inferiors that are not running yet or that have exited
1180 already. See also "New commands" and "New options" below.
1182 * New tracing features
1184 GDB's tracepoint facility now includes several new features:
1186 ** Trace state variables
1188 GDB tracepoints now include support for trace state variables, which
1189 are variables managed by the target agent during a tracing
1190 experiment. They are useful for tracepoints that trigger each
1191 other, so for instance one tracepoint can count hits in a variable,
1192 and then a second tracepoint has a condition that is true when the
1193 count reaches a particular value. Trace state variables share the
1194 $-syntax of GDB convenience variables, and can appear in both
1195 tracepoint actions and condition expressions. Use the "tvariable"
1196 command to create, and "info tvariables" to view; see "Trace State
1197 Variables" in the manual for more detail.
1201 GDB now includes an option for defining fast tracepoints, which
1202 targets may implement more efficiently, such as by installing a jump
1203 into the target agent rather than a trap instruction. The resulting
1204 speedup can be by two orders of magnitude or more, although the
1205 tradeoff is that some program locations on some target architectures
1206 might not allow fast tracepoint installation, for instance if the
1207 instruction to be replaced is shorter than the jump. To request a
1208 fast tracepoint, use the "ftrace" command, with syntax identical to
1209 the regular trace command.
1211 ** Disconnected tracing
1213 It is now possible to detach GDB from the target while it is running
1214 a trace experiment, then reconnect later to see how the experiment
1215 is going. In addition, a new variable disconnected-tracing lets you
1216 tell the target agent whether to continue running a trace if the
1217 connection is lost unexpectedly.
1221 GDB now has the ability to save the trace buffer into a file, and
1222 then use that file as a target, similarly to you can do with
1223 corefiles. You can select trace frames, print data that was
1224 collected in them, and use tstatus to display the state of the
1225 tracing run at the moment that it was saved. To create a trace
1226 file, use "tsave <filename>", and to use it, do "target tfile
1229 ** Circular trace buffer
1231 You can ask the target agent to handle the trace buffer as a
1232 circular buffer, discarding the oldest trace frames to make room for
1233 newer ones, by setting circular-trace-buffer to on. This feature may
1234 not be available for all target agents.
1239 The disassemble command, when invoked with two arguments, now requires
1240 the arguments to be comma-separated.
1243 The info variables command now displays variable definitions. Files
1244 which only declare a variable are not shown.
1247 The source command is now capable of sourcing Python scripts.
1248 This feature is dependent on the debugger being build with Python
1251 Related to this enhancement is also the introduction of a new command
1252 "set script-extension" (see below).
1254 * New commands (for set/show, see "New options" below)
1256 record save [<FILENAME>]
1257 Save a file (in core file format) containing the process record
1258 execution log for replay debugging at a later time.
1260 record restore <FILENAME>
1261 Restore the process record execution log that was saved at an
1262 earlier time, for replay debugging.
1264 add-inferior [-copies <N>] [-exec <FILENAME>]
1267 clone-inferior [-copies <N>] [ID]
1268 Make a new inferior ready to execute the same program another
1269 inferior has loaded.
1274 maint info program-spaces
1275 List the program spaces loaded into GDB.
1277 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1278 show remote interrupt-sequence
1279 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1280 as the sequence to the remote target in order to interrupt the execution.
1281 Ctrl-C is a default. Some system prefers BREAK which is high level of
1282 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1283 Magic SysRq g. It is BREAK signal and character 'g'.
1285 set remote interrupt-on-connect [on | off]
1286 show remote interrupt-on-connect
1287 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1288 remote target when gdb connects to it. This is needed when you debug
1291 set remotebreak [on | off]
1293 Deprecated. Use "set/show remote interrupt-sequence" instead.
1295 tvariable $NAME [ = EXP ]
1296 Create or modify a trace state variable.
1299 List trace state variables and their values.
1301 delete tvariable $NAME ...
1302 Delete one or more trace state variables.
1305 Evaluate the given expressions without collecting anything into the
1306 trace buffer. (Valid in tracepoint actions only.)
1308 ftrace FN / FILE:LINE / *ADDR
1309 Define a fast tracepoint at the given function, line, or address.
1311 * New expression syntax
1313 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1314 GDB now parses 0b101010 identically with 42.
1318 set follow-exec-mode new|same
1319 show follow-exec-mode
1320 Control whether GDB reuses the same inferior across an exec call or
1321 creates a new one. This is useful to be able to restart the old
1322 executable after the inferior having done an exec call.
1324 set default-collect EXPR, ...
1325 show default-collect
1326 Define a list of expressions to be collected at each tracepoint.
1327 This is a useful way to ensure essential items are not overlooked,
1328 such as registers or a critical global variable.
1330 set disconnected-tracing
1331 show disconnected-tracing
1332 If set to 1, the target is instructed to continue tracing if it
1333 loses its connection to GDB. If 0, the target is to stop tracing
1336 set circular-trace-buffer
1337 show circular-trace-buffer
1338 If set to on, the target is instructed to use a circular trace buffer
1339 and discard the oldest trace frames instead of stopping the trace due
1340 to a full trace buffer. If set to off, the trace stops when the buffer
1341 fills up. Some targets may not support this.
1343 set script-extension off|soft|strict
1344 show script-extension
1345 If set to "off", the debugger does not perform any script language
1346 recognition, and all sourced files are assumed to be GDB scripts.
1347 If set to "soft" (the default), files are sourced according to
1348 filename extension, falling back to GDB scripts if the first
1350 If set to "strict", files are sourced according to filename extension.
1352 set ada trust-PAD-over-XVS on|off
1353 show ada trust-PAD-over-XVS
1354 If off, activate a workaround against a bug in the debugging information
1355 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1356 the GCC sources for more information about the GNAT encoding and
1357 PAD types in particular). It is always safe to set this option to
1358 off, but this introduces a slight performance penalty. The default
1361 * Python API Improvements
1363 ** GDB provides the new class gdb.LazyString. This is useful in
1364 some pretty-printing cases. The new method gdb.Value.lazy_string
1365 provides a simple way to create objects of this type.
1367 ** The fields returned by gdb.Type.fields now have an
1368 `is_base_class' attribute.
1370 ** The new method gdb.Type.range returns the range of an array type.
1372 ** The new method gdb.parse_and_eval can be used to parse and
1373 evaluate an expression.
1375 * New remote packets
1378 Define a trace state variable.
1381 Get the current value of a trace state variable.
1384 Set desired tracing behavior upon disconnection.
1387 Set the trace buffer to be linear or circular.
1390 Get data about the tracepoints currently in use.
1394 Process record now works correctly with hardware watchpoints.
1396 Multiple bug fixes have been made to the mips-irix port, making it
1397 much more reliable. In particular:
1398 - Debugging threaded applications is now possible again. Previously,
1399 GDB would hang while starting the program, or while waiting for
1400 the program to stop at a breakpoint.
1401 - Attaching to a running process no longer hangs.
1402 - An error occurring while loading a core file has been fixed.
1403 - Changing the value of the PC register now works again. This fixes
1404 problems observed when using the "jump" command, or when calling
1405 a function from GDB, or even when assigning a new value to $pc.
1406 - With the "finish" and "return" commands, the return value for functions
1407 returning a small array is now correctly printed.
1408 - It is now possible to break on shared library code which gets executed
1409 during a shared library init phase (code executed while executing
1410 their .init section). Previously, the breakpoint would have no effect.
1411 - GDB is now able to backtrace through the signal handler for
1412 non-threaded programs.
1414 PIE (Position Independent Executable) programs debugging is now supported.
1415 This includes debugging execution of PIC (Position Independent Code) shared
1416 libraries although for that, it should be possible to run such libraries as an
1419 *** Changes in GDB 7.0
1421 * GDB now has an interface for JIT compilation. Applications that
1422 dynamically generate code can create symbol files in memory and register
1423 them with GDB. For users, the feature should work transparently, and
1424 for JIT developers, the interface is documented in the GDB manual in the
1425 "JIT Compilation Interface" chapter.
1427 * Tracepoints may now be conditional. The syntax is as for
1428 breakpoints; either an "if" clause appended to the "trace" command,
1429 or the "condition" command is available. GDB sends the condition to
1430 the target for evaluation using the same bytecode format as is used
1431 for tracepoint actions.
1433 * The disassemble command now supports: an optional /r modifier, print the
1434 raw instructions in hex as well as in symbolic form, and an optional /m
1435 modifier to print mixed source+assembly.
1437 * Process record and replay
1439 In a architecture environment that supports ``process record and
1440 replay'', ``process record and replay'' target can record a log of
1441 the process execution, and replay it with both forward and reverse
1444 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1445 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1446 set execution-direction {forward|reverse}, for targets that support
1449 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1450 feature is available with a native GDB running on kernel version
1453 * GDB now has support for multi-byte and wide character sets on the
1454 target. Strings whose character type is wchar_t, char16_t, or
1455 char32_t are now correctly printed. GDB supports wide- and unicode-
1456 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1457 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1458 `printf'. This feature requires iconv to work properly; if your
1459 system does not have a working iconv, GDB can use GNU libiconv. See
1460 the installation instructions for more information.
1462 * GDB now supports automatic retrieval of shared library files from
1463 remote targets. To use this feature, specify a system root that begins
1464 with the `remote:' prefix, either via the `set sysroot' command or via
1465 the `--with-sysroot' configure-time option.
1467 * "info sharedlibrary" now takes an optional regex of libraries to show,
1468 and it now reports if a shared library has no debugging information.
1470 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1471 now complete on file names.
1473 * When completing in expressions, gdb will attempt to limit
1474 completions to allowable structure or union fields, where appropriate.
1475 For instance, consider:
1477 # struct example { int f1; double f2; };
1478 # struct example variable;
1481 If the user types TAB at the end of this command line, the available
1482 completions will be "f1" and "f2".
1484 * Inlined functions are now supported. They show up in backtraces, and
1485 the "step", "next", and "finish" commands handle them automatically.
1487 * GDB now supports the token-splicing (##) and stringification (#)
1488 operators when expanding macros. It also supports variable-arity
1491 * GDB now supports inspecting extra signal information, exported by
1492 the new $_siginfo convenience variable. The feature is currently
1493 implemented on linux ARM, i386 and amd64.
1495 * GDB can now display the VFP floating point registers and NEON vector
1496 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1497 can provide these registers (requires Linux 2.6.30 or later). Remote
1498 and simulator targets may also provide them.
1500 * New remote packets
1503 Search memory for a sequence of bytes.
1506 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1507 operation over reliable transport links. Use of this packet is
1508 controlled by the `set remote noack-packet' command.
1511 Kill the process with the specified process ID. Use this in preference
1512 to `k' when multiprocess protocol extensions are supported.
1515 Obtains additional operating system information
1519 Read or write additional signal information.
1521 * Removed remote protocol undocumented extension
1523 An undocumented extension to the remote protocol's `S' stop reply
1524 packet that permited the stub to pass a process id was removed.
1525 Remote servers should use the `T' stop reply packet instead.
1527 * GDB now supports multiple function calling conventions according to the
1528 DWARF-2 DW_AT_calling_convention function attribute.
1530 * The SH target utilizes the aforementioned change to distinguish between gcc
1531 and Renesas calling convention. It also adds the new CLI commands
1532 `set/show sh calling-convention'.
1534 * GDB can now read compressed debug sections, as produced by GNU gold
1535 with the --compress-debug-sections=zlib flag.
1537 * 64-bit core files are now supported on AIX.
1539 * Thread switching is now supported on Tru64.
1541 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1542 which will be allocated using malloc later in program execution.
1544 * The qXfer:libraries:read remote procotol packet now allows passing a
1545 list of section offsets.
1547 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1548 conditions handling signals delivered during attach or thread creation
1549 have also been fixed.
1551 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1552 From the user's standpoint, all unqualified instances of True and False
1553 are treated as the standard definitions, regardless of context.
1555 * GDB now parses C++ symbol and type names more flexibly. For
1558 template<typename T> class C { };
1561 GDB will now correctly handle all of:
1563 ptype C<char const *>
1564 ptype C<char const*>
1565 ptype C<const char *>
1566 ptype C<const char*>
1568 * New features in the GDB remote stub, gdbserver
1570 - The "--wrapper" command-line argument tells gdbserver to use a
1571 wrapper program to launch programs for debugging.
1573 - On PowerPC and S/390 targets, it is now possible to use a single
1574 gdbserver executable to debug both 32-bit and 64-bit programs.
1575 (This requires gdbserver itself to be built as a 64-bit executable.)
1577 - gdbserver uses the new noack protocol mode for TCP connections to
1578 reduce communications latency, if also supported and enabled in GDB.
1580 - Support for the sparc64-linux-gnu target is now included in
1583 - The amd64-linux build of gdbserver now supports debugging both
1584 32-bit and 64-bit programs.
1586 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1587 now support hardware watchpoints, and will use them automatically
1592 GDB now has support for scripting using Python. Whether this is
1593 available is determined at configure time.
1595 New GDB commands can now be written in Python.
1597 * Ada tasking support
1599 Ada tasks can now be inspected in GDB. The following commands have
1603 Print the list of Ada tasks.
1605 Print detailed information about task number N.
1607 Print the task number of the current task.
1609 Switch the context of debugging to task number N.
1611 * Support for user-defined prefixed commands. The "define" command can
1612 add new commands to existing prefixes, e.g. "target".
1614 * Multi-inferior, multi-process debugging.
1616 GDB now has generalized support for multi-inferior debugging. See
1617 "Debugging Multiple Inferiors" in the manual for more information.
1618 Although availability still depends on target support, the command
1619 set is more uniform now. The GNU/Linux specific multi-forks support
1620 has been migrated to this new framework. This implied some user
1621 visible changes; see "New commands" and also "Removed commands"
1624 * Target descriptions can now describe the target OS ABI. See the
1625 "Target Description Format" section in the user manual for more
1628 * Target descriptions can now describe "compatible" architectures
1629 to indicate that the target can execute applications for a different
1630 architecture in addition to those for the main target architecture.
1631 See the "Target Description Format" section in the user manual for
1634 * Multi-architecture debugging.
1636 GDB now includes general supports for debugging applications on
1637 hybrid systems that use more than one single processor architecture
1638 at the same time. Each such hybrid architecture still requires
1639 specific support to be added. The only hybrid architecture supported
1640 in this version of GDB is the Cell Broadband Engine.
1642 * GDB now supports integrated debugging of Cell/B.E. applications that
1643 use both the PPU and SPU architectures. To enable support for hybrid
1644 Cell/B.E. debugging, you need to configure GDB to support both the
1645 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1646 --enable-targets configure option.
1648 * Non-stop mode debugging.
1650 For some targets, GDB now supports an optional mode of operation in
1651 which you can examine stopped threads while other threads continue
1652 to execute freely. This is referred to as non-stop mode, with the
1653 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1654 section in the user manual for more information.
1656 To be able to support remote non-stop debugging, a remote stub needs
1657 to implement the non-stop mode remote protocol extensions, as
1658 described in the "Remote Non-Stop" section of the user manual. The
1659 GDB remote stub, gdbserver, has been adjusted to support these
1660 extensions on linux targets.
1662 * New commands (for set/show, see "New options" below)
1664 catch syscall [NAME(S) | NUMBER(S)]
1665 Catch system calls. Arguments, which should be names of system
1666 calls or their numbers, mean catch only those syscalls. Without
1667 arguments, every syscall will be caught. When the inferior issues
1668 any of the specified syscalls, GDB will stop and announce the system
1669 call, both when it is called and when its call returns. This
1670 feature is currently available with a native GDB running on the
1671 Linux Kernel, under the following architectures: x86, x86_64,
1672 PowerPC and PowerPC64.
1674 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1676 Search memory for a sequence of bytes.
1678 maint set python print-stack
1679 maint show python print-stack
1680 Show a stack trace when an error is encountered in a Python script.
1683 Invoke CODE by passing it to the Python interpreter.
1688 These allow macros to be defined, undefined, and listed
1692 Show operating system information about processes.
1695 List the inferiors currently under GDB's control.
1698 Switch focus to inferior number NUM.
1701 Detach from inferior number NUM.
1704 Kill inferior number NUM.
1708 set spu stop-on-load
1709 show spu stop-on-load
1710 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1712 set spu auto-flush-cache
1713 show spu auto-flush-cache
1714 Control whether to automatically flush the software-managed cache
1715 during Cell/B.E. debugging.
1717 set sh calling-convention
1718 show sh calling-convention
1719 Control the calling convention used when calling SH target functions.
1722 show debug timestamp
1723 Control display of timestamps with GDB debugging output.
1725 set disassemble-next-line
1726 show disassemble-next-line
1727 Control display of disassembled source lines or instructions when
1730 set remote noack-packet
1731 show remote noack-packet
1732 Set/show the use of remote protocol QStartNoAckMode packet. See above
1733 under "New remote packets."
1735 set remote query-attached-packet
1736 show remote query-attached-packet
1737 Control use of remote protocol `qAttached' (query-attached) packet.
1739 set remote read-siginfo-object
1740 show remote read-siginfo-object
1741 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1744 set remote write-siginfo-object
1745 show remote write-siginfo-object
1746 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1749 set remote reverse-continue
1750 show remote reverse-continue
1751 Control use of remote protocol 'bc' (reverse-continue) packet.
1753 set remote reverse-step
1754 show remote reverse-step
1755 Control use of remote protocol 'bs' (reverse-step) packet.
1757 set displaced-stepping
1758 show displaced-stepping
1759 Control displaced stepping mode. Displaced stepping is a way to
1760 single-step over breakpoints without removing them from the debuggee.
1761 Also known as "out-of-line single-stepping".
1764 show debug displaced
1765 Control display of debugging info for displaced stepping.
1767 maint set internal-error
1768 maint show internal-error
1769 Control what GDB does when an internal error is detected.
1771 maint set internal-warning
1772 maint show internal-warning
1773 Control what GDB does when an internal warning is detected.
1778 Use a wrapper program to launch programs for debugging.
1780 set multiple-symbols (all|ask|cancel)
1781 show multiple-symbols
1782 The value of this variable can be changed to adjust the debugger behavior
1783 when an expression or a breakpoint location contains an ambiguous symbol
1784 name (an overloaded function name, for instance).
1786 set breakpoint always-inserted
1787 show breakpoint always-inserted
1788 Keep breakpoints always inserted in the target, as opposed to inserting
1789 them when resuming the target, and removing them when the target stops.
1790 This option can improve debugger performance on slow remote targets.
1792 set arm fallback-mode (arm|thumb|auto)
1793 show arm fallback-mode
1794 set arm force-mode (arm|thumb|auto)
1796 These commands control how ARM GDB determines whether instructions
1797 are ARM or Thumb. The default for both settings is auto, which uses
1798 the current CPSR value for instructions without symbols; previous
1799 versions of GDB behaved as if "set arm fallback-mode arm".
1801 set disable-randomization
1802 show disable-randomization
1803 Standalone programs run with the virtual address space randomization enabled
1804 by default on some platforms. This option keeps the addresses stable across
1805 multiple debugging sessions.
1809 Control whether other threads are stopped or not when some thread hits
1814 Requests that asynchronous execution is enabled in the target, if available.
1815 In this case, it's possible to resume target in the background, and interact
1816 with GDB while the target is running. "show target-async" displays the
1817 current state of asynchronous execution of the target.
1819 set target-wide-charset
1820 show target-wide-charset
1821 The target-wide-charset is the name of the character set that GDB
1822 uses when printing characters whose type is wchar_t.
1824 set tcp auto-retry (on|off)
1826 set tcp connect-timeout
1827 show tcp connect-timeout
1828 These commands allow GDB to retry failed TCP connections to a remote stub
1829 with a specified timeout period; this is useful if the stub is launched
1830 in parallel with GDB but may not be ready to accept connections immediately.
1832 set libthread-db-search-path
1833 show libthread-db-search-path
1834 Control list of directories which GDB will search for appropriate
1837 set schedule-multiple (on|off)
1838 show schedule-multiple
1839 Allow GDB to resume all threads of all processes or only threads of
1840 the current process.
1844 Use more aggressive caching for accesses to the stack. This improves
1845 performance of remote debugging (particularly backtraces) without
1846 affecting correctness.
1848 set interactive-mode (on|off|auto)
1849 show interactive-mode
1850 Control whether GDB runs in interactive mode (on) or not (off).
1851 When in interactive mode, GDB waits for the user to answer all
1852 queries. Otherwise, GDB does not wait and assumes the default
1853 answer. When set to auto (the default), GDB determines which
1854 mode to use based on the stdin settings.
1859 For program forks, this is replaced by the new more generic `info
1860 inferiors' command. To list checkpoints, you can still use the
1861 `info checkpoints' command, which was an alias for the `info forks'
1865 Replaced by the new `inferior' command. To switch between
1866 checkpoints, you can still use the `restart' command, which was an
1867 alias for the `fork' command.
1870 This is removed, since some targets don't have a notion of
1871 processes. To switch between processes, you can still use the
1872 `inferior' command using GDB's own inferior number.
1875 For program forks, this is replaced by the new more generic `kill
1876 inferior' command. To delete a checkpoint, you can still use the
1877 `delete checkpoint' command, which was an alias for the `delete
1881 For program forks, this is replaced by the new more generic `detach
1882 inferior' command. To detach a checkpoint, you can still use the
1883 `detach checkpoint' command, which was an alias for the `detach
1886 * New native configurations
1888 x86/x86_64 Darwin i[34567]86-*-darwin*
1890 x86_64 MinGW x86_64-*-mingw*
1894 Lattice Mico32 lm32-*
1895 x86 DICOS i[34567]86-*-dicos*
1896 x86_64 DICOS x86_64-*-dicos*
1899 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1900 (mingw32ce) debugging.
1906 These commands were actually not implemented on any target.
1908 *** Changes in GDB 6.8
1910 * New native configurations
1912 NetBSD/hppa hppa*-*netbsd*
1913 Xtensa GNU/Linux xtensa*-*-linux*
1917 NetBSD/hppa hppa*-*-netbsd*
1918 Xtensa GNU/Lunux xtensa*-*-linux*
1920 * Change in command line behavior -- corefiles vs. process ids.
1922 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1923 attaching to process NUMBER fails, GDB no longer attempts to open a
1924 core file named NUMBER. Attaching to a program using the -c option
1925 is no longer supported. Instead, use the '-p' or '--pid' options.
1927 * GDB can now be built as a native debugger for debugging Windows x86
1928 (mingw32) Portable Executable (PE) programs.
1930 * Pending breakpoints no longer change their number when their address
1933 * GDB now supports breakpoints with multiple locations,
1934 including breakpoints on C++ constructors, inside C++ templates,
1935 and in inlined functions.
1937 * GDB's ability to debug optimized code has been improved. GDB more
1938 accurately identifies function bodies and lexical blocks that occupy
1939 more than one contiguous range of addresses.
1941 * Target descriptions can now describe registers for PowerPC.
1943 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1944 registers on PowerPC targets.
1946 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1947 targets even when the libthread_db library is not available.
1949 * The GDB remote stub, gdbserver, now supports the new file transfer
1950 commands (remote put, remote get, and remote delete).
1952 * The GDB remote stub, gdbserver, now supports run and attach in
1953 extended-remote mode.
1955 * hppa*64*-*-hpux11* target broken
1956 The debugger is unable to start a program and fails with the following
1957 error: "Error trying to get information about dynamic linker".
1958 The gdb-6.7 release is also affected.
1960 * GDB now supports the --enable-targets= configure option to allow
1961 building a single GDB executable that supports multiple remote
1962 target architectures.
1964 * GDB now supports debugging C and C++ programs which use the
1965 Decimal Floating Point extension. In addition, the PowerPC target
1966 now has a set of pseudo-registers to inspect decimal float values
1967 stored in two consecutive float registers.
1969 * The -break-insert MI command can optionally create pending
1972 * Improved support for debugging Ada
1973 Many improvements to the Ada language support have been made. These
1975 - Better support for Ada2005 interface types
1976 - Improved handling of arrays and slices in general
1977 - Better support for Taft-amendment types
1978 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1980 - Improved command completion in Ada
1983 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1988 set print frame-arguments (all|scalars|none)
1989 show print frame-arguments
1990 The value of this variable can be changed to control which argument
1991 values should be printed by the debugger when displaying a frame.
1996 Transfer files to and from a remote target, and delete remote files.
2003 Transfer files to and from a remote target, and delete remote files.
2005 * New remote packets
2012 Open, close, read, write, and delete files on the remote system.
2015 Attach to an existing process on the remote system, in extended-remote
2019 Run a new process on the remote system, in extended-remote mode.
2021 *** Changes in GDB 6.7
2023 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2024 bfd, libiberty and opcodes, as revealed by static analysis donated by
2025 Coverity, Inc. (http://scan.coverity.com).
2027 * When looking up multiply-defined global symbols, GDB will now prefer the
2028 symbol definition in the current shared library if it was built using the
2029 -Bsymbolic linker option.
2031 * When the Text User Interface (TUI) is not configured, GDB will now
2032 recognize the -tui command-line option and print a message that the TUI
2035 * The GDB remote stub, gdbserver, now has lower overhead for high
2036 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2038 * GDB for MIPS targets now autodetects whether a remote target provides
2039 32-bit or 64-bit register values.
2041 * Support for C++ member pointers has been improved.
2043 * GDB now understands XML target descriptions, which specify the
2044 target's overall architecture. GDB can read a description from
2045 a local file or over the remote serial protocol.
2047 * Vectors of single-byte data use a new integer type which is not
2048 automatically displayed as character or string data.
2050 * The /s format now works with the print command. It displays
2051 arrays of single-byte integers and pointers to single-byte integers
2054 * Target descriptions can now describe target-specific registers,
2055 for architectures which have implemented the support (currently
2056 only ARM, M68K, and MIPS).
2058 * GDB and the GDB remote stub, gdbserver, now support the XScale
2061 * The GDB remote stub, gdbserver, has been updated to support
2062 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2063 has been rewritten to use the standard GDB remote protocol.
2065 * GDB can now step into C++ functions which are called through thunks.
2067 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2069 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2070 layout. It also supports a TextSeg= and DataSeg= response when only
2071 segment base addresses (rather than offsets) are available.
2073 * The /i format now outputs any trailing branch delay slot instructions
2074 immediately following the last instruction within the count specified.
2076 * The GDB remote protocol "T" stop reply packet now supports a
2077 "library" response. Combined with the new "qXfer:libraries:read"
2078 packet, this response allows GDB to debug shared libraries on targets
2079 where the operating system manages the list of loaded libraries (e.g.
2080 Windows and SymbianOS).
2082 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2083 (DLLs) on Windows and Windows CE targets.
2085 * GDB now supports a faster verification that a .debug file matches its binary
2086 according to its build-id signature, if the signature is present.
2092 Enable or disable hardware flow control (RTS/CTS) on the serial port
2093 when debugging using remote targets.
2095 set mem inaccessible-by-default
2096 show mem inaccessible-by-default
2097 If the target supplies a memory map, for instance via the remote
2098 protocol's "qXfer:memory-map:read" packet, setting this variable
2099 prevents GDB from accessing memory outside the memory map. This
2100 is useful for targets with memory mapped registers or which react
2101 badly to accesses of unmapped address space.
2103 set breakpoint auto-hw
2104 show breakpoint auto-hw
2105 If the target supplies a memory map, for instance via the remote
2106 protocol's "qXfer:memory-map:read" packet, setting this variable
2107 lets GDB use hardware breakpoints automatically for memory regions
2108 where it can not use software breakpoints. This covers both the
2109 "break" command and internal breakpoints used for other commands
2110 including "next" and "finish".
2113 catch exception unhandled
2114 Stop the program execution when Ada exceptions are raised.
2117 Stop the program execution when an Ada assertion failed.
2121 Set an alternate system root for target files. This is a more
2122 general version of "set solib-absolute-prefix", which is now
2123 an alias to "set sysroot".
2126 Provide extended SPU facility status information. This set of
2127 commands is available only when debugging the Cell/B.E. SPU
2130 * New native configurations
2132 OpenBSD/sh sh*-*openbsd*
2135 unset tdesc filename
2137 Use the specified local file as an XML target description, and do
2138 not query the target for its built-in description.
2142 OpenBSD/sh sh*-*-openbsd*
2143 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2144 Toshiba Media Processor mep-elf
2146 * New remote packets
2149 Ignore the specified signals; pass them directly to the debugged program
2150 without stopping other threads or reporting them to GDB.
2152 qXfer:features:read:
2153 Read an XML target description from the target, which describes its
2158 Read or write contents of an spufs file on the target system. These
2159 packets are available only on the Cell/B.E. SPU architecture.
2161 qXfer:libraries:read:
2162 Report the loaded shared libraries. Combined with new "T" packet
2163 response, this packet allows GDB to debug shared libraries on
2164 targets where the operating system manages the list of loaded
2165 libraries (e.g. Windows and SymbianOS).
2169 Support for these obsolete configurations has been removed.
2177 i[34567]86-*-lynxos*
2178 i[34567]86-*-netware*
2179 i[34567]86-*-sco3.2v5*
2180 i[34567]86-*-sco3.2v4*
2182 i[34567]86-*-sysv4.2*
2185 i[34567]86-*-unixware2*
2186 i[34567]86-*-unixware*
2195 * Other removed features
2202 Various m68k-only ROM monitors.
2209 Various Renesas ROM monitors and debugging interfaces for SH and
2214 Support for a Macraigor serial interface to on-chip debugging.
2215 GDB does not directly support the newer parallel or USB
2220 A debug information format. The predecessor to DWARF 2 and
2221 DWARF 3, which are still supported.
2223 Support for the HP aCC compiler on HP-UX/PA-RISC
2225 SOM-encapsulated symbolic debugging information, automatic
2226 invocation of pxdb, and the aCC custom C++ ABI. This does not
2227 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2228 with aCC can still be debugged on an assembly level.
2230 MIPS ".pdr" sections
2232 A MIPS-specific format used to describe stack frame layout
2233 in debugging information.
2237 GDB could work with an older version of Guile to debug
2238 the interpreter and Scheme programs running in it.
2240 set mips stack-arg-size
2241 set mips saved-gpreg-size
2243 Use "set mips abi" to control parameter passing for MIPS.
2245 *** Changes in GDB 6.6
2250 Cell Broadband Engine SPU spu-elf
2252 * GDB can now be configured as a cross-debugger targeting native Windows
2253 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2254 running on a Windows system over TCP/IP to debug Windows programs.
2256 * The GDB remote stub, gdbserver, has been updated to support Windows and
2257 Cygwin debugging. Both single-threaded and multi-threaded programs are
2260 * The "set trust-readonly-sections" command works again. This command was
2261 broken in GDB 6.3, 6.4, and 6.5.
2263 * The "load" command now supports writing to flash memory, if the remote
2264 stub provides the required support.
2266 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2267 longer requires symbolic debug information (e.g. DWARF-2).
2272 unset substitute-path
2273 show substitute-path
2274 Manage a list of substitution rules that GDB uses to rewrite the name
2275 of the directories where the sources are located. This can be useful
2276 for instance when the sources were moved to a different location
2277 between compilation and debugging.
2281 Print each CLI command as it is executed. Each command is prefixed with
2282 a number of `+' symbols representing the nesting depth.
2283 The source command now has a `-v' option to enable the same feature.
2287 The ARM Demon monitor support (RDP protocol, "target rdp").
2289 Kernel Object Display, an embedded debugging feature which only worked with
2290 an obsolete version of Cisco IOS.
2292 The 'set download-write-size' and 'show download-write-size' commands.
2294 * New remote packets
2297 Tell a stub about GDB client features, and request remote target features.
2298 The first feature implemented is PacketSize, which allows the target to
2299 specify the size of packets it can handle - to minimize the number of
2300 packets required and improve performance when connected to a remote
2304 Fetch an OS auxilliary vector from the remote stub. This packet is a
2305 more efficient replacement for qPart:auxv:read.
2307 qXfer:memory-map:read:
2308 Fetch a memory map from the remote stub, including information about
2309 RAM, ROM, and flash memory devices.
2314 Erase and program a flash memory device.
2316 * Removed remote packets
2319 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2320 used it, and only gdbserver implemented it.
2322 *** Changes in GDB 6.5
2326 Renesas M32C/M16C m32c-elf
2328 Morpho Technologies ms1 ms1-elf
2332 init-if-undefined Initialize a convenience variable, but
2333 only if it doesn't already have a value.
2335 The following commands are presently only implemented for native GNU/Linux:
2337 checkpoint Save a snapshot of the program state.
2339 restart <n> Return the program state to a
2340 previously saved state.
2342 info checkpoints List currently saved checkpoints.
2344 delete-checkpoint <n> Delete a previously saved checkpoint.
2346 set|show detach-on-fork Tell gdb whether to detach from a newly
2347 forked process, or to keep debugging it.
2349 info forks List forks of the user program that
2350 are available to be debugged.
2352 fork <n> Switch to debugging one of several
2353 forks of the user program that are
2354 available to be debugged.
2356 delete-fork <n> Delete a fork from the list of forks
2357 that are available to be debugged (and
2358 kill the forked process).
2360 detach-fork <n> Delete a fork from the list of forks
2361 that are available to be debugged (and
2362 allow the process to continue).
2366 Morpho Technologies ms2 ms1-elf
2368 * Improved Windows host support
2370 GDB now builds as a cross debugger hosted on i686-mingw32, including
2371 native console support, and remote communications using either
2372 network sockets or serial ports.
2374 * Improved Modula-2 language support
2376 GDB can now print most types in the Modula-2 syntax. This includes:
2377 basic types, set types, record types, enumerated types, range types,
2378 pointer types and ARRAY types. Procedure var parameters are correctly
2379 printed and hexadecimal addresses and character constants are also
2380 written in the Modula-2 syntax. Best results can be obtained by using
2381 GNU Modula-2 together with the -gdwarf-2 command line option.
2385 The ARM rdi-share module.
2387 The Netware NLM debug server.
2389 *** Changes in GDB 6.4
2391 * New native configurations
2393 OpenBSD/arm arm*-*-openbsd*
2394 OpenBSD/mips64 mips64-*-openbsd*
2398 Morpho Technologies ms1 ms1-elf
2400 * New command line options
2402 --batch-silent As for --batch, but totally silent.
2403 --return-child-result The debugger will exist with the same value
2404 the child (debugged) program exited with.
2405 --eval-command COMMAND, -ex COMMAND
2406 Execute a single GDB CLI command. This may be
2407 specified multiple times and in conjunction
2408 with the --command (-x) option.
2410 * Deprecated commands removed
2412 The following commands, that were deprecated in 2000, have been
2416 set|show arm disassembly-flavor set|show arm disassembler
2417 othernames set arm disassembler
2418 set|show remotedebug set|show debug remote
2419 set|show archdebug set|show debug arch
2420 set|show eventdebug set|show debug event
2423 * New BSD user-level threads support
2425 It is now possible to debug programs using the user-level threads
2426 library on OpenBSD and FreeBSD. Currently supported (target)
2429 FreeBSD/amd64 x86_64-*-freebsd*
2430 FreeBSD/i386 i386-*-freebsd*
2431 OpenBSD/i386 i386-*-openbsd*
2433 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2434 are not yet supported.
2436 * New support for Matsushita MN10300 w/sim added
2437 (Work in progress). mn10300-elf.
2439 * REMOVED configurations and files
2441 VxWorks and the XDR protocol *-*-vxworks
2442 Motorola MCORE mcore-*-*
2443 National Semiconductor NS32000 ns32k-*-*
2445 * New "set print array-indexes" command
2447 After turning this setting "on", GDB prints the index of each element
2448 when displaying arrays. The default is "off" to preserve the previous
2451 * VAX floating point support
2453 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2455 * User-defined command support
2457 In addition to using $arg0..$arg9 for argument passing, it is now possible
2458 to use $argc to determine now many arguments have been passed. See the
2459 section on user-defined commands in the user manual for more information.
2461 *** Changes in GDB 6.3:
2463 * New command line option
2465 GDB now accepts -l followed by a number to set the timeout for remote
2468 * GDB works with GCC -feliminate-dwarf2-dups
2470 GDB now supports a more compact representation of DWARF-2 debug
2471 information using DW_FORM_ref_addr references. These are produced
2472 by GCC with the option -feliminate-dwarf2-dups and also by some
2473 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2474 to use -feliminate-dwarf2-dups.
2476 * Internationalization
2478 When supported by the host system, GDB will be built with
2479 internationalization (libintl). The task of marking up the sources is
2480 continued, we're looking forward to our first translation.
2484 Initial support for debugging programs compiled with the GNAT
2485 implementation of the Ada programming language has been integrated
2486 into GDB. In this release, support is limited to expression evaluation.
2488 * New native configurations
2490 GNU/Linux/m32r m32r-*-linux-gnu
2494 GDB's remote protocol now includes support for the 'p' packet. This
2495 packet is used to fetch individual registers from a remote inferior.
2497 * END-OF-LIFE registers[] compatibility module
2499 GDB's internal register infrastructure has been completely rewritten.
2500 The new infrastructure making possible the implementation of key new
2501 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2504 GDB 6.3 will be the last release to include the the registers[]
2505 compatibility module that allowed out-of-date configurations to
2506 continue to work. This change directly impacts the following
2516 powerpc bdm protocol
2518 Unless there is activity to revive these configurations, they will be
2519 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2521 * OBSOLETE configurations and files
2523 Configurations that have been declared obsolete in this release have
2524 been commented out. Unless there is activity to revive these
2525 configurations, the next release of GDB will have their sources
2526 permanently REMOVED.
2535 *** Changes in GDB 6.2.1:
2537 * MIPS `break main; run' gave an heuristic-fence-post warning
2539 When attempting to run even a simple program, a warning about
2540 heuristic-fence-post being hit would be reported. This problem has
2543 * MIPS IRIX 'long double' crashed GDB
2545 When examining a long double variable, GDB would get a segmentation
2546 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2547 IRIX long double values).
2551 A bug in the VAX stack code was causing problems with the "next"
2552 command. This problem has been fixed.
2554 *** Changes in GDB 6.2:
2556 * Fix for ``many threads''
2558 On GNU/Linux systems that use the NPTL threads library, a program
2559 rapidly creating and deleting threads would confuse GDB leading to the
2562 ptrace: No such process.
2563 thread_db_get_info: cannot get thread info: generic error
2565 This problem has been fixed.
2567 * "-async" and "-noasync" options removed.
2569 Support for the broken "-noasync" option has been removed (it caused
2572 * New ``start'' command.
2574 This command runs the program until the begining of the main procedure.
2576 * New BSD Kernel Data Access Library (libkvm) interface
2578 Using ``target kvm'' it is now possible to debug kernel core dumps and
2579 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2580 platforms. Currently supported (native-only) configurations are:
2582 FreeBSD/amd64 x86_64-*-freebsd*
2583 FreeBSD/i386 i?86-*-freebsd*
2584 NetBSD/i386 i?86-*-netbsd*
2585 NetBSD/m68k m68*-*-netbsd*
2586 NetBSD/sparc sparc-*-netbsd*
2587 OpenBSD/amd64 x86_64-*-openbsd*
2588 OpenBSD/i386 i?86-*-openbsd*
2589 OpenBSD/m68k m68*-openbsd*
2590 OpenBSD/sparc sparc-*-openbsd*
2592 * Signal trampoline code overhauled
2594 Many generic problems with GDB's signal handling code have been fixed.
2595 These include: backtraces through non-contiguous stacks; recognition
2596 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2597 call; backtrace through a signal trampoline; step into and out of
2598 signal handlers; and single-stepping in the signal trampoline.
2600 Please note that kernel bugs are a limiting factor here. These
2601 features have been shown to work on an s390 GNU/Linux system that
2602 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2604 * Cygwin support for DWARF 2 added.
2606 * New native configurations
2608 GNU/Linux/hppa hppa*-*-linux*
2609 OpenBSD/hppa hppa*-*-openbsd*
2610 OpenBSD/m68k m68*-*-openbsd*
2611 OpenBSD/m88k m88*-*-openbsd*
2612 OpenBSD/powerpc powerpc-*-openbsd*
2613 NetBSD/vax vax-*-netbsd*
2614 OpenBSD/vax vax-*-openbsd*
2616 * END-OF-LIFE frame compatibility module
2618 GDB's internal frame infrastructure has been completely rewritten.
2619 The new infrastructure making it possible to support key new features
2620 including DWARF 2 Call Frame Information. To aid in the task of
2621 migrating old configurations to this new infrastructure, a
2622 compatibility module, that allowed old configurations to continue to
2623 work, was also included.
2625 GDB 6.2 will be the last release to include this frame compatibility
2626 module. This change directly impacts the following configurations:
2636 Unless there is activity to revive these configurations, they will be
2637 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2639 * REMOVED configurations and files
2641 Sun 3, running SunOS 3 m68*-*-sunos3*
2642 Sun 3, running SunOS 4 m68*-*-sunos4*
2643 Sun 2, running SunOS 3 m68000-*-sunos3*
2644 Sun 2, running SunOS 4 m68000-*-sunos4*
2645 Motorola 680x0 running LynxOS m68*-*-lynxos*
2646 AT&T 3b1/Unix pc m68*-att-*
2647 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2648 decstation mips-dec-* mips-little-*
2649 riscos mips-*-riscos* mips-*-sysv*
2650 sonymips mips-sony-*
2651 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2653 *** Changes in GDB 6.1.1:
2655 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2657 The TUI (Text-mode User Interface) is now built as part of a default
2658 GDB configuration. It is enabled by either selecting the TUI with the
2659 command line option "-i=tui" or by running the separate "gdbtui"
2660 program. For more information on the TUI, see the manual "Debugging
2663 * Pending breakpoint support (also included in GDB 6.1)
2665 Support has been added to allow you to specify breakpoints in shared
2666 libraries that have not yet been loaded. If a breakpoint location
2667 cannot be found, and the "breakpoint pending" option is set to auto,
2668 GDB queries you if you wish to make the breakpoint pending on a future
2669 shared-library load. If and when GDB resolves the breakpoint symbol,
2670 the pending breakpoint is removed as one or more regular breakpoints
2673 Pending breakpoints are very useful for GCJ Java debugging.
2675 * Fixed ISO-C build problems
2677 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2678 non ISO-C code that stopped them being built using a more strict ISO-C
2679 compiler (e.g., IBM's C compiler).
2681 * Fixed build problem on IRIX 5
2683 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2684 wasn't able to compile compile on an IRIX 5 system.
2686 * Added execute permission to gdb/gdbserver/configure
2688 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2689 permission. This bug would cause configure to fail on a number of
2690 systems (Solaris, IRIX). Ref: server/519.
2692 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2694 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2695 has been updated to use constant array sizes.
2697 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2699 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2700 its generated DWARF Call Frame Info. This encoding was causing GDB to
2701 panic, that panic has been fixed. Ref: gdb/1628.
2703 * Fixed a problem when examining parameters in shared library code.
2705 When examining parameters in optimized shared library code generated
2706 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2707 not available''. GDB now correctly displays the variable's value.
2709 *** Changes in GDB 6.1:
2711 * Removed --with-mmalloc
2713 Support for the mmalloc memory manager has been removed, as it
2714 conflicted with the internal gdb byte cache.
2716 * Changes in AMD64 configurations
2718 The AMD64 target now includes the %cs and %ss registers. As a result
2719 the AMD64 remote protocol has changed; this affects the floating-point
2720 and SSE registers. If you rely on those registers for your debugging,
2721 you should upgrade gdbserver on the remote side.
2723 * Revised SPARC target
2725 The SPARC target has been completely revised, incorporating the
2726 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2727 support for LynxOS and SunOS 4 has been dropped. Calling functions
2728 from within GDB on operating systems with a non-executable stack
2729 (Solaris, OpenBSD) now works.
2733 GDB has a new C++ demangler which does a better job on the mangled
2734 names generated by current versions of g++. It also runs faster, so
2735 with this and other changes gdb should now start faster on large C++
2738 * DWARF 2 Location Expressions
2740 GDB support for location expressions has been extended to support function
2741 arguments and frame bases. Older versions of GDB could crash when they
2744 * C++ nested types and namespaces
2746 GDB's support for nested types and namespaces in C++ has been
2747 improved, especially if you use the DWARF 2 debugging format. (This
2748 is the default for recent versions of GCC on most platforms.)
2749 Specifically, if you have a class "Inner" defined within a class or
2750 namespace "Outer", then GDB realizes that the class's name is
2751 "Outer::Inner", not simply "Inner". This should greatly reduce the
2752 frequency of complaints about not finding RTTI symbols. In addition,
2753 if you are stopped at inside of a function defined within a namespace,
2754 GDB modifies its name lookup accordingly.
2756 * New native configurations
2758 NetBSD/amd64 x86_64-*-netbsd*
2759 OpenBSD/amd64 x86_64-*-openbsd*
2760 OpenBSD/alpha alpha*-*-openbsd*
2761 OpenBSD/sparc sparc-*-openbsd*
2762 OpenBSD/sparc64 sparc64-*-openbsd*
2764 * New debugging protocols
2766 M32R with SDI protocol m32r-*-elf*
2768 * "set prompt-escape-char" command deleted.
2770 The command "set prompt-escape-char" has been deleted. This command,
2771 and its very obscure effet on GDB's prompt, was never documented,
2772 tested, nor mentioned in the NEWS file.
2774 * OBSOLETE configurations and files
2776 Configurations that have been declared obsolete in this release have
2777 been commented out. Unless there is activity to revive these
2778 configurations, the next release of GDB will have their sources
2779 permanently REMOVED.
2781 Sun 3, running SunOS 3 m68*-*-sunos3*
2782 Sun 3, running SunOS 4 m68*-*-sunos4*
2783 Sun 2, running SunOS 3 m68000-*-sunos3*
2784 Sun 2, running SunOS 4 m68000-*-sunos4*
2785 Motorola 680x0 running LynxOS m68*-*-lynxos*
2786 AT&T 3b1/Unix pc m68*-att-*
2787 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2788 decstation mips-dec-* mips-little-*
2789 riscos mips-*-riscos* mips-*-sysv*
2790 sonymips mips-sony-*
2791 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2793 * REMOVED configurations and files
2795 SGI Irix-4.x mips-sgi-irix4 or iris4
2796 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2797 Z8000 simulator z8k-zilog-none or z8ksim
2798 Matsushita MN10200 w/simulator mn10200-*-*
2799 H8/500 simulator h8500-hitachi-hms or h8500hms
2800 HP/PA running BSD hppa*-*-bsd*
2801 HP/PA running OSF/1 hppa*-*-osf*
2802 HP/PA Pro target hppa*-*-pro*
2803 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2804 386BSD i[3456]86-*-bsd*
2805 Sequent family i[3456]86-sequent-sysv4*
2806 i[3456]86-sequent-sysv*
2807 i[3456]86-sequent-bsd*
2808 SPARC running LynxOS sparc-*-lynxos*
2809 SPARC running SunOS 4 sparc-*-sunos4*
2810 Tsqware Sparclet sparclet-*-*
2811 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2813 *** Changes in GDB 6.0:
2817 Support for debugging the Objective-C programming language has been
2818 integrated into GDB.
2820 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2822 DWARF 2's Call Frame Information makes available compiler generated
2823 information that more exactly describes the program's run-time stack.
2824 By using this information, GDB is able to provide more robust stack
2827 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2828 have been updated to use a new backtrace mechanism which includes
2829 DWARF 2 CFI support.
2833 GDB's remote protocol has been extended to include support for hosted
2834 file I/O (where the remote target uses GDB's file system). See GDB's
2835 remote protocol documentation for details.
2837 * All targets using the new architecture framework.
2839 All of GDB's targets have been updated to use the new internal
2840 architecture framework. The way is now open for future GDB releases
2841 to include cross-architecture native debugging support (i386 on amd64,
2844 * GNU/Linux's Thread Local Storage (TLS)
2846 GDB now includes support for for the GNU/Linux implementation of
2847 per-thread variables.
2849 * GNU/Linux's Native POSIX Thread Library (NPTL)
2851 GDB's thread code has been updated to work with either the new
2852 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2854 * Separate debug info.
2856 GDB, in conjunction with BINUTILS, now supports a mechanism for
2857 automatically loading debug information from a separate file. Instead
2858 of shipping full debug and non-debug versions of system libraries,
2859 system integrators can now instead ship just the stripped libraries
2860 and optional debug files.
2862 * DWARF 2 Location Expressions
2864 DWARF 2 Location Expressions allow the compiler to more completely
2865 describe the location of variables (even in optimized code) to the
2868 GDB now includes preliminary support for location expressions (support
2869 for DW_OP_piece is still missing).
2873 A number of long standing bugs that caused GDB to die while starting a
2874 Java application have been fixed. GDB's Java support is now
2875 considered "useable".
2877 * GNU/Linux support for fork, vfork, and exec.
2879 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2880 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2883 * GDB supports logging output to a file
2885 There are two new commands, "set logging" and "show logging", which can be
2886 used to capture GDB's output to a file.
2888 * The meaning of "detach" has changed for gdbserver
2890 The "detach" command will now resume the application, as documented. To
2891 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2894 * d10v, m68hc11 `regs' command deprecated
2896 The `info registers' command has been updated so that it displays the
2897 registers using a format identical to the old `regs' command.
2901 A new command, "maint set profile on/off", has been added. This command can
2902 be used to enable or disable profiling while running GDB, to profile a
2903 session or a set of commands. In addition there is a new configure switch,
2904 "--enable-profiling", which will cause GDB to be compiled with profiling
2905 data, for more informative profiling results.
2907 * Default MI syntax changed to "mi2".
2909 The default MI (machine interface) syntax, enabled by the command line
2910 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2911 "mi1", can be enabled by specifying the option "-i=mi1".
2913 Support for the original "mi0" syntax (included in GDB 5.0) has been
2916 Fix for gdb/192: removed extraneous space when displaying frame level.
2917 Fix for gdb/672: update changelist is now output in mi list format.
2918 Fix for gdb/702: a -var-assign that updates the value now shows up
2919 in a subsequent -var-update.
2921 * New native configurations.
2923 FreeBSD/amd64 x86_64-*-freebsd*
2925 * Multi-arched targets.
2927 HP/PA HPUX11 hppa*-*-hpux*
2928 Renesas M32R/D w/simulator m32r-*-elf*
2930 * OBSOLETE configurations and files
2932 Configurations that have been declared obsolete in this release have
2933 been commented out. Unless there is activity to revive these
2934 configurations, the next release of GDB will have their sources
2935 permanently REMOVED.
2937 Z8000 simulator z8k-zilog-none or z8ksim
2938 Matsushita MN10200 w/simulator mn10200-*-*
2939 H8/500 simulator h8500-hitachi-hms or h8500hms
2940 HP/PA running BSD hppa*-*-bsd*
2941 HP/PA running OSF/1 hppa*-*-osf*
2942 HP/PA Pro target hppa*-*-pro*
2943 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2944 Sequent family i[3456]86-sequent-sysv4*
2945 i[3456]86-sequent-sysv*
2946 i[3456]86-sequent-bsd*
2947 Tsqware Sparclet sparclet-*-*
2948 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2950 * REMOVED configurations and files
2953 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2954 IBM AIX PS/2 i[3456]86-*-aix
2955 i386 running Mach 3.0 i[3456]86-*-mach3*
2956 i386 running Mach i[3456]86-*-mach*
2957 i386 running OSF/1 i[3456]86-*osf1mk*
2958 HP/Apollo 68k Family m68*-apollo*-sysv*,
2960 m68*-hp-bsd*, m68*-hp-hpux*
2961 Argonaut Risc Chip (ARC) arc-*-*
2962 Mitsubishi D30V d30v-*-*
2963 Fujitsu FR30 fr30-*-elf*
2964 OS/9000 i[34]86-*-os9k
2965 I960 with MON960 i960-*-coff
2967 * MIPS $fp behavior changed
2969 The convenience variable $fp, for the MIPS, now consistently returns
2970 the address of the current frame's base. Previously, depending on the
2971 context, $fp could refer to either $sp or the current frame's base
2972 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2973 The GNU Source-Level Debugger''.
2975 *** Changes in GDB 5.3:
2977 * GNU/Linux shared library multi-threaded performance improved.
2979 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2980 `/proc', in preference to `ptrace' for memory reads. This may result
2981 in an improvement in the start-up time of multi-threaded, shared
2982 library applications when run under GDB. One GDB user writes: ``loads
2983 shared libs like mad''.
2985 * ``gdbserver'' now supports multi-threaded applications on some targets
2987 Support for debugging multi-threaded applications which use
2988 the GNU/Linux LinuxThreads package has been added for
2989 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2990 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2992 * GDB now supports C/C++ preprocessor macros.
2994 GDB now expands preprocessor macro invocations in C/C++ expressions,
2995 and provides various commands for showing macro definitions and how
2998 The new command `macro expand EXPRESSION' expands any macro
2999 invocations in expression, and shows the result.
3001 The new command `show macro MACRO-NAME' shows the definition of the
3002 macro named MACRO-NAME, and where it was defined.
3004 Most compilers don't include information about macros in the debugging
3005 information by default. In GCC 3.1, for example, you need to compile
3006 your program with the options `-gdwarf-2 -g3'. If the macro
3007 information is present in the executable, GDB will read it.
3009 * Multi-arched targets.
3011 DEC Alpha (partial) alpha*-*-*
3012 DEC VAX (partial) vax-*-*
3014 National Semiconductor NS32000 (partial) ns32k-*-*
3015 Motorola 68000 (partial) m68k-*-*
3016 Motorola MCORE mcore-*-*
3020 Fujitsu FRV architecture added by Red Hat frv*-*-*
3023 * New native configurations
3025 Alpha NetBSD alpha*-*-netbsd*
3026 SH NetBSD sh*-*-netbsdelf*
3027 MIPS NetBSD mips*-*-netbsd*
3028 UltraSPARC NetBSD sparc64-*-netbsd*
3030 * OBSOLETE configurations and files
3032 Configurations that have been declared obsolete in this release have
3033 been commented out. Unless there is activity to revive these
3034 configurations, the next release of GDB will have their sources
3035 permanently REMOVED.
3037 Mitsubishi D30V d30v-*-*
3038 OS/9000 i[34]86-*-os9k
3039 IBM AIX PS/2 i[3456]86-*-aix
3040 Fujitsu FR30 fr30-*-elf*
3041 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3042 Argonaut Risc Chip (ARC) arc-*-*
3043 i386 running Mach 3.0 i[3456]86-*-mach3*
3044 i386 running Mach i[3456]86-*-mach*
3045 i386 running OSF/1 i[3456]86-*osf1mk*
3046 HP/Apollo 68k Family m68*-apollo*-sysv*,
3048 m68*-hp-bsd*, m68*-hp-hpux*
3049 I960 with MON960 i960-*-coff
3051 * OBSOLETE languages
3053 CHILL, a Pascal like language used by telecommunications companies.
3055 * REMOVED configurations and files
3057 AMD 29k family via UDI a29k-amd-udi, udi29k
3058 A29K VxWorks a29k-*-vxworks
3059 AMD 29000 embedded, using EBMON a29k-none-none
3060 AMD 29000 embedded with COFF a29k-none-coff
3061 AMD 29000 embedded with a.out a29k-none-aout
3063 testsuite/gdb.hp/gdb.threads-hp/ directory
3065 * New command "set max-user-call-depth <nnn>"
3067 This command allows the user to limit the call depth of user-defined
3068 commands. The default is 1024.
3070 * Changes in FreeBSD/i386 native debugging.
3072 Support for the "generate-core-file" has been added.
3074 * New commands "dump", "append", and "restore".
3076 These commands allow data to be copied from target memory
3077 to a bfd-format or binary file (dump and append), and back
3078 from a file into memory (restore).
3080 * Improved "next/step" support on multi-processor Alpha Tru64.
3082 The previous single-step mechanism could cause unpredictable problems,
3083 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3084 of a software single-step mechanism prevents this.
3086 *** Changes in GDB 5.2.1:
3094 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3095 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3096 Fix, by Joel Brobecker imported from mainline.
3098 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3099 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3100 Fix, by Fred Fish, imported from mainline.
3102 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3103 Surprisingly enough, it works now.
3104 By Michal Ludvig, imported from mainline.
3106 i386 hardware watchpoint support:
3107 avoid misses on second run for some targets.
3108 By Pierre Muller, imported from mainline.
3110 *** Changes in GDB 5.2:
3112 * New command "set trust-readonly-sections on[off]".
3114 This command is a hint that tells gdb that read-only sections
3115 really are read-only (ie. that their contents will not change).
3116 In this mode, gdb will go to the object file rather than the
3117 target to read memory from read-only sections (such as ".text").
3118 This can be a significant performance improvement on some
3119 (notably embedded) targets.
3121 * New command "generate-core-file" (or "gcore").
3123 This new gdb command allows the user to drop a core file of the child
3124 process state at any time. So far it's been implemented only for
3125 GNU/Linux and Solaris, but should be relatively easily ported to other
3126 hosts. Argument is core file name (defaults to core.<pid>).
3128 * New command line option
3130 GDB now accepts --pid or -p followed by a process id.
3132 * Change in command line behavior -- corefiles vs. process ids.
3134 There is a subtle behavior in the way in which GDB handles
3135 command line arguments. The first non-flag argument is always
3136 a program to debug, but the second non-flag argument may either
3137 be a corefile or a process id. Previously, GDB would attempt to
3138 open the second argument as a corefile, and if that failed, would
3139 issue a superfluous error message and then attempt to attach it as
3140 a process. Now, if the second argument begins with a non-digit,
3141 it will be treated as a corefile. If it begins with a digit,
3142 GDB will attempt to attach it as a process, and if no such process
3143 is found, will then attempt to open it as a corefile.
3145 * Changes in ARM configurations.
3147 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3148 configuration is fully multi-arch.
3150 * New native configurations
3152 ARM NetBSD arm*-*-netbsd*
3153 x86 OpenBSD i[3456]86-*-openbsd*
3154 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3155 Sparc64 running FreeBSD sparc64-*-freebsd*
3159 Sanyo XStormy16 xstormy16-elf
3161 * OBSOLETE configurations and files
3163 Configurations that have been declared obsolete in this release have
3164 been commented out. Unless there is activity to revive these
3165 configurations, the next release of GDB will have their sources
3166 permanently REMOVED.
3168 AMD 29k family via UDI a29k-amd-udi, udi29k
3169 A29K VxWorks a29k-*-vxworks
3170 AMD 29000 embedded, using EBMON a29k-none-none
3171 AMD 29000 embedded with COFF a29k-none-coff
3172 AMD 29000 embedded with a.out a29k-none-aout
3174 testsuite/gdb.hp/gdb.threads-hp/ directory
3176 * REMOVED configurations and files
3178 TI TMS320C80 tic80-*-*
3180 PowerPC Solaris powerpcle-*-solaris*
3181 PowerPC Windows NT powerpcle-*-cygwin32
3182 PowerPC Netware powerpc-*-netware*
3183 Harris/CXUX m88k m88*-harris-cxux*
3184 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3185 ns32k-utek-sysv* ns32k-utek-*
3186 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3187 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3188 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3189 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3190 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3192 * Changes to command line processing
3194 The new `--args' feature can be used to specify command-line arguments
3195 for the inferior from gdb's command line.
3197 * Changes to key bindings
3199 There is a new `operate-and-get-next' function bound to `C-o'.
3201 *** Changes in GDB 5.1.1
3203 Fix compile problem on DJGPP.
3205 Fix a problem with floating-point registers on the i386 being
3208 Fix to stop GDB crashing on .debug_str debug info.
3210 Numerous documentation fixes.
3212 Numerous testsuite fixes.
3214 *** Changes in GDB 5.1:
3216 * New native configurations
3218 Alpha FreeBSD alpha*-*-freebsd*
3219 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3220 MIPS GNU/Linux mips*-*-linux*
3221 MIPS SGI Irix 6.x mips*-sgi-irix6*
3222 ia64 AIX ia64-*-aix*
3223 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3227 Motorola 68HC11 and 68HC12 m68hc11-elf
3229 UltraSparc running GNU/Linux sparc64-*-linux*
3231 * OBSOLETE configurations and files
3233 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3234 Harris/CXUX m88k m88*-harris-cxux*
3235 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3236 ns32k-utek-sysv* ns32k-utek-*
3237 TI TMS320C80 tic80-*-*
3239 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3240 PowerPC Solaris powerpcle-*-solaris*
3241 PowerPC Windows NT powerpcle-*-cygwin32
3242 PowerPC Netware powerpc-*-netware*
3243 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3244 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3245 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3246 Apple Macintosh (MPW) host N/A
3248 stuff.c (Program to stuff files into a specially prepared space in kdb)
3249 kdb-start.c (Main loop for the standalone kernel debugger)
3251 Configurations that have been declared obsolete in this release have
3252 been commented out. Unless there is activity to revive these
3253 configurations, the next release of GDB will have their sources
3254 permanently REMOVED.
3256 * REMOVED configurations and files
3258 Altos 3068 m68*-altos-*
3259 Convex c1-*-*, c2-*-*
3261 ARM RISCix arm-*-* (as host)
3265 * GDB has been converted to ISO C.
3267 GDB's source code has been converted to ISO C. In particular, the
3268 sources are fully protoized, and rely on standard headers being
3273 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3275 * The MI enabled by default.
3277 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3278 revised and enabled by default. Packages which use GDB as a debugging
3279 engine behind a UI or another front end are encouraged to switch to
3280 using the GDB/MI interface, instead of the old annotations interface
3281 which is now deprecated.
3283 * Support for debugging Pascal programs.
3285 GDB now includes support for debugging Pascal programs. The following
3286 main features are supported:
3288 - Pascal-specific data types such as sets;
3290 - automatic recognition of Pascal sources based on file-name
3293 - Pascal-style display of data types, variables, and functions;
3295 - a Pascal expression parser.
3297 However, some important features are not yet supported.
3299 - Pascal string operations are not supported at all;
3301 - there are some problems with boolean types;
3303 - Pascal type hexadecimal constants are not supported
3304 because they conflict with the internal variables format;
3306 - support for Pascal objects and classes is not full yet;
3308 - unlike Pascal, GDB is case-sensitive for symbol names.
3310 * Changes in completion.
3312 Commands such as `shell', `run' and `set args', which pass arguments
3313 to inferior programs, now complete on file names, similar to what
3314 users expect at the shell prompt.
3316 Commands which accept locations, such as `disassemble', `print',
3317 `breakpoint', `until', etc. now complete on filenames as well as
3318 program symbols. Thus, if you type "break foob TAB", and the source
3319 files linked into the programs include `foobar.c', that file name will
3320 be one of the candidates for completion. However, file names are not
3321 considered for completion after you typed a colon that delimits a file
3322 name from a name of a function in that file, as in "break foo.c:bar".
3324 `set demangle-style' completes on available demangling styles.
3326 * New platform-independent commands:
3328 It is now possible to define a post-hook for a command as well as a
3329 hook that runs before the command. For more details, see the
3330 documentation of `hookpost' in the GDB manual.
3332 * Changes in GNU/Linux native debugging.
3334 Support for debugging multi-threaded programs has been completely
3335 revised for all platforms except m68k and sparc. You can now debug as
3336 many threads as your system allows you to have.
3338 Attach/detach is supported for multi-threaded programs.
3340 Support for SSE registers was added for x86. This doesn't work for
3341 multi-threaded programs though.
3343 * Changes in MIPS configurations.
3345 Multi-arch support is enabled for all MIPS configurations.
3347 GDB can now be built as native debugger on SGI Irix 6.x systems for
3348 debugging n32 executables. (Debugging 64-bit executables is not yet
3351 * Unified support for hardware watchpoints in all x86 configurations.
3353 Most (if not all) native x86 configurations support hardware-assisted
3354 breakpoints and watchpoints in a unified manner. This support
3355 implements debug register sharing between watchpoints, which allows to
3356 put a virtually infinite number of watchpoints on the same address,
3357 and also supports watching regions up to 16 bytes with several debug
3360 The new maintenance command `maintenance show-debug-regs' toggles
3361 debugging print-outs in functions that insert, remove, and test
3362 watchpoints and hardware breakpoints.
3364 * Changes in the DJGPP native configuration.
3366 New command ``info dos sysinfo'' displays assorted information about
3367 the CPU, OS, memory, and DPMI server.
3369 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3370 display information about segment descriptors stored in GDT, LDT, and
3373 New commands ``info dos pde'' and ``info dos pte'' display entries
3374 from Page Directory and Page Tables (for now works with CWSDPMI only).
3375 New command ``info dos address-pte'' displays the Page Table entry for
3376 a given linear address.
3378 GDB can now pass command lines longer than 126 characters to the
3379 program being debugged (requires an update to the libdbg.a library
3380 which is part of the DJGPP development kit).
3382 DWARF2 debug info is now supported.
3384 It is now possible to `step' and `next' through calls to `longjmp'.
3386 * Changes in documentation.
3388 All GDB documentation was converted to GFDL, the GNU Free
3389 Documentation License.
3391 Tracepoints-related commands are now fully documented in the GDB
3394 TUI, the Text-mode User Interface, is now documented in the manual.
3396 Tracepoints-related commands are now fully documented in the GDB
3399 The "GDB Internals" manual now has an index. It also includes
3400 documentation of `ui_out' functions, GDB coding standards, x86
3401 hardware watchpoints, and memory region attributes.
3403 * GDB's version number moved to ``version.in''
3405 The Makefile variable VERSION has been replaced by the file
3406 ``version.in''. People creating GDB distributions should update the
3407 contents of this file.
3411 GUD support is now a standard part of the EMACS distribution.
3413 *** Changes in GDB 5.0:
3415 * Improved support for debugging FP programs on x86 targets
3417 Unified and much-improved support for debugging floating-point
3418 programs on all x86 targets. In particular, ``info float'' now
3419 displays the FP registers in the same format on all x86 targets, with
3420 greater level of detail.
3422 * Improvements and bugfixes in hardware-assisted watchpoints
3424 It is now possible to watch array elements, struct members, and
3425 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3426 on x86 targets no longer erroneously trigger when the address is
3429 * Improvements in the native DJGPP version of GDB
3431 The distribution now includes all the scripts and auxiliary files
3432 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3433 machines ``out of the box''.
3435 The DJGPP version can now debug programs that use signals. It is
3436 possible to catch signals that happened in the debuggee, deliver
3437 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3438 would kill the program being debugged.) Programs that hook hardware
3439 interrupts (keyboard, timer, etc.) can also be debugged.
3441 It is now possible to debug DJGPP programs that redirect their
3442 standard handles or switch them to raw (as opposed to cooked) mode, or
3443 even close them. The command ``run < foo > bar'' works as expected,
3444 and ``info terminal'' reports useful information about the debuggee's
3445 terminal, including raw/cooked mode, redirection, etc.
3447 The DJGPP version now uses termios functions for console I/O, which
3448 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3451 DOS-style file names with drive letters are now fully supported by
3454 It is now possible to debug DJGPP programs that switch their working
3455 directory. It is also possible to rerun the debuggee any number of
3456 times without restarting GDB; thus, you can use the same setup,
3457 breakpoints, etc. for many debugging sessions.
3459 * New native configurations
3461 ARM GNU/Linux arm*-*-linux*
3462 PowerPC GNU/Linux powerpc-*-linux*
3466 Motorola MCore mcore-*-*
3467 x86 VxWorks i[3456]86-*-vxworks*
3468 PowerPC VxWorks powerpc-*-vxworks*
3469 TI TMS320C80 tic80-*-*
3471 * OBSOLETE configurations
3473 Altos 3068 m68*-altos-*
3474 Convex c1-*-*, c2-*-*
3476 ARM RISCix arm-*-* (as host)
3479 Configurations that have been declared obsolete will be commented out,
3480 but the code will be left in place. If there is no activity to revive
3481 these configurations before the next release of GDB, the sources will
3482 be permanently REMOVED.
3484 * Gould support removed
3486 Support for the Gould PowerNode and NP1 has been removed.
3488 * New features for SVR4
3490 On SVR4 native platforms (such as Solaris), if you attach to a process
3491 without first loading a symbol file, GDB will now attempt to locate and
3492 load symbols from the running process's executable file.
3494 * Many C++ enhancements
3496 C++ support has been greatly improved. Overload resolution now works properly
3497 in almost all cases. RTTI support is on the way.
3499 * Remote targets can connect to a sub-program
3501 A popen(3) style serial-device has been added. This device starts a
3502 sub-process (such as a stand-alone simulator) and then communicates
3503 with that. The sub-program to run is specified using the syntax
3504 ``|<program> <args>'' vis:
3506 (gdb) set remotedebug 1
3507 (gdb) target extended-remote |mn10300-elf-sim program-args
3509 * MIPS 64 remote protocol
3511 A long standing bug in the mips64 remote protocol where by GDB
3512 expected certain 32 bit registers (ex SR) to be transfered as 32
3513 instead of 64 bits has been fixed.
3515 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3516 added to provide backward compatibility with older versions of GDB.
3518 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3520 The command ``set remotebinarydownload'' command has been replaced by
3521 ``set remote X-packet''. Other commands in ``set remote'' family
3522 include ``set remote P-packet''.
3524 * Breakpoint commands accept ranges.
3526 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3527 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3528 ``tracepoint passcount'' also accepts a range of tracepoints.
3530 * ``apropos'' command added.
3532 The ``apropos'' command searches through command names and
3533 documentation strings, printing out matches, making it much easier to
3534 try to find a command that does what you are looking for.
3538 A new machine oriented interface (MI) has been added to GDB. This
3539 interface is designed for debug environments running GDB as a separate
3540 process. This is part of the long term libGDB project. See the
3541 "GDB/MI" chapter of the GDB manual for further information. It can be
3542 enabled by configuring with:
3544 .../configure --enable-gdbmi
3546 *** Changes in GDB-4.18:
3548 * New native configurations
3550 HP-UX 10.20 hppa*-*-hpux10.20
3551 HP-UX 11.x hppa*-*-hpux11.0*
3552 M68K GNU/Linux m68*-*-linux*
3556 Fujitsu FR30 fr30-*-elf*
3557 Intel StrongARM strongarm-*-*
3558 Mitsubishi D30V d30v-*-*
3560 * OBSOLETE configurations
3562 Gould PowerNode, NP1 np1-*-*, pn-*-*
3564 Configurations that have been declared obsolete will be commented out,
3565 but the code will be left in place. If there is no activity to revive
3566 these configurations before the next release of GDB, the sources will
3567 be permanently REMOVED.
3571 As a compatibility experiment, GDB's source files buildsym.h and
3572 buildsym.c have been converted to pure standard C, no longer
3573 containing any K&R compatibility code. We believe that all systems in
3574 use today either come with a standard C compiler, or have a GCC port
3575 available. If this is not true, please report the affected
3576 configuration to bug-gdb@gnu.org immediately. See the README file for
3577 information about getting a standard C compiler if you don't have one
3582 GDB now uses readline 2.2.
3584 * set extension-language
3586 You can now control the mapping between filename extensions and source
3587 languages by using the `set extension-language' command. For instance,
3588 you can ask GDB to treat .c files as C++ by saying
3589 set extension-language .c c++
3590 The command `info extensions' lists all of the recognized extensions
3591 and their associated languages.
3593 * Setting processor type for PowerPC and RS/6000
3595 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3596 you can use the `set processor' command to specify what variant of the
3597 PowerPC family you are debugging. The command
3601 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3602 following PowerPC and RS6000 variants:
3604 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3605 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3607 403GC IBM PowerPC 403GC
3608 505 Motorola PowerPC 505
3609 860 Motorola PowerPC 860 or 850
3610 601 Motorola PowerPC 601
3611 602 Motorola PowerPC 602
3612 603 Motorola/IBM PowerPC 603 or 603e
3613 604 Motorola PowerPC 604 or 604e
3614 750 Motorola/IBM PowerPC 750 or 750
3616 At the moment, this command just tells GDB what to name the
3617 special-purpose processor registers. Since almost all the affected
3618 registers are inaccessible to user-level programs, this command is
3619 only useful for remote debugging in its present form.
3623 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3624 more extensive support for HP-UX. Added features include shared
3625 library support, kernel threads and hardware watchpoints for 11.00,
3626 support for HP's ANSI C and C++ compilers, and a compatibility mode
3627 for xdb and dbx commands.
3631 HP's donation includes the new concept of catchpoints, which is a
3632 generalization of the old catch command. On HP-UX, it is now possible
3633 to catch exec, fork, and vfork, as well as library loading.
3635 This means that the existing catch command has changed; its first
3636 argument now specifies the type of catch to be set up. See the
3637 output of "help catch" for a list of catchpoint types.
3639 * Debugging across forks
3641 On HP-UX, you can choose which process to debug when a fork() happens
3646 HP has donated a curses-based terminal user interface (TUI). To get
3647 it, build with --enable-tui. Although this can be enabled for any
3648 configuration, at present it only works for native HP debugging.
3650 * GDB remote protocol additions
3652 A new protocol packet 'X' that writes binary data is now available.
3653 Default behavior is to try 'X', then drop back to 'M' if the stub
3654 fails to respond. The settable variable `remotebinarydownload'
3655 allows explicit control over the use of 'X'.
3657 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3658 full 64-bit address. The command
3660 set remoteaddresssize 32
3662 can be used to revert to the old behaviour. For existing remote stubs
3663 the change should not be noticed, as the additional address information
3666 In order to assist in debugging stubs, you may use the maintenance
3667 command `packet' to send any text string to the stub. For instance,
3669 maint packet heythere
3671 sends the packet "$heythere#<checksum>". Note that it is very easy to
3672 disrupt a debugging session by sending the wrong packet at the wrong
3675 The compare-sections command allows you to compare section data on the
3676 target to what is in the executable file without uploading or
3677 downloading, by comparing CRC checksums.
3679 * Tracing can collect general expressions
3681 You may now collect general expressions at tracepoints. This requires
3682 further additions to the target-side stub; see tracepoint.c and
3683 doc/agentexpr.texi for further details.
3685 * mask-address variable for Mips
3687 For Mips targets, you may control the zeroing of the upper 32 bits of
3688 a 64-bit address by entering `set mask-address on'. This is mainly
3689 of interest to users of embedded R4xxx and R5xxx processors.
3691 * Higher serial baud rates
3693 GDB's serial code now allows you to specify baud rates 57600, 115200,
3694 230400, and 460800 baud. (Note that your host system may not be able
3695 to achieve all of these rates.)
3699 The i960 configuration now includes an initial implementation of a
3700 builtin simulator, contributed by Jim Wilson.
3703 *** Changes in GDB-4.17:
3705 * New native configurations
3707 Alpha GNU/Linux alpha*-*-linux*
3708 Unixware 2.x i[3456]86-unixware2*
3709 Irix 6.x mips*-sgi-irix6*
3710 PowerPC GNU/Linux powerpc-*-linux*
3711 PowerPC Solaris powerpcle-*-solaris*
3712 Sparc GNU/Linux sparc-*-linux*
3713 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3717 Argonaut Risc Chip (ARC) arc-*-*
3718 Hitachi H8/300S h8300*-*-*
3719 Matsushita MN10200 w/simulator mn10200-*-*
3720 Matsushita MN10300 w/simulator mn10300-*-*
3721 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3722 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3723 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3724 Mitsubishi D10V w/simulator d10v-*-*
3725 Mitsubishi M32R/D w/simulator m32r-*-elf*
3726 Tsqware Sparclet sparclet-*-*
3727 NEC V850 w/simulator v850-*-*
3729 * New debugging protocols
3731 ARM with RDI protocol arm*-*-*
3732 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3733 DDB and LSI variants of PMON protocol mips*-*-*
3734 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3735 PowerPC with SDS protocol powerpc{,le}-*-eabi
3736 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3740 All configurations can now understand and use the DWARF 2 debugging
3741 format. The choice is automatic, if the symbol file contains DWARF 2
3746 GDB now includes basic Java language support. This support is
3747 only useful with Java compilers that produce native machine code.
3749 * solib-absolute-prefix and solib-search-path
3751 For SunOS and SVR4 shared libraries, you may now set the prefix for
3752 loading absolute shared library symbol files, and the search path for
3753 locating non-absolute shared library symbol files.
3755 * Live range splitting
3757 GDB can now effectively debug code for which GCC has performed live
3758 range splitting as part of its optimization. See gdb/doc/LRS for
3759 more details on the expected format of the stabs information.
3763 GDB's support for the GNU Hurd, including thread debugging, has been
3764 updated to work with current versions of the Hurd.
3768 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3769 instruction set. ARM GDB automatically detects when Thumb
3770 instructions are in use, and adjusts disassembly and backtracing
3775 GDB's MIPS target configurations now handle the MIP16 16-bit
3780 GDB now includes support for overlays; if an executable has been
3781 linked such that multiple sections are based at the same address, GDB
3782 will decide which section to use for symbolic info. You can choose to
3783 control the decision manually, using overlay commands, or implement
3784 additional target-side support and use "overlay load-target" to bring
3785 in the overlay mapping. Do "help overlay" for more detail.
3789 The command "info symbol <address>" displays information about
3790 the symbol at the specified address.
3794 The standard remote protocol now includes an extension that allows
3795 asynchronous collection and display of trace data. This requires
3796 extensive support in the target-side debugging stub. Tracing mode
3797 includes a new interaction mode in GDB and new commands: see the
3798 file tracepoint.c for more details.
3802 Configurations for embedded MIPS now include a simulator contributed
3803 by Cygnus Solutions. The simulator supports the instruction sets
3804 of most MIPS variants.
3808 Sparc configurations may now include the ERC32 simulator contributed
3809 by the European Space Agency. The simulator is not built into
3810 Sparc targets by default; configure with --enable-sim to include it.
3814 For target configurations that may include multiple variants of a
3815 basic architecture (such as MIPS and SH), you may now set the
3816 architecture explicitly. "set arch" sets, "info arch" lists
3817 the possible architectures.
3819 *** Changes in GDB-4.16:
3821 * New native configurations
3823 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3824 M68K NetBSD m68k-*-netbsd*
3825 PowerPC AIX 4.x powerpc-*-aix*
3826 PowerPC MacOS powerpc-*-macos*
3827 PowerPC Windows NT powerpcle-*-cygwin32
3828 RS/6000 AIX 4.x rs6000-*-aix4*
3832 ARM with RDP protocol arm-*-*
3833 I960 with MON960 i960-*-coff
3834 MIPS VxWorks mips*-*-vxworks*
3835 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3836 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3838 Matra Sparclet sparclet-*-*
3842 The powerpc-eabi configuration now includes the PSIM simulator,
3843 contributed by Andrew Cagney, with assistance from Mike Meissner.
3844 PSIM is a very elaborate model of the PowerPC, including not only
3845 basic instruction set execution, but also details of execution unit
3846 performance and I/O hardware. See sim/ppc/README for more details.
3850 GDB now works with Solaris 2.5.
3852 * Windows 95/NT native
3854 GDB will now work as a native debugger on Windows 95 and Windows NT.
3855 To build it from source, you must use the "gnu-win32" environment,
3856 which uses a DLL to emulate enough of Unix to run the GNU tools.
3857 Further information, binaries, and sources are available at
3858 ftp.cygnus.com, under pub/gnu-win32.
3860 * dont-repeat command
3862 If a user-defined command includes the command `dont-repeat', then the
3863 command will not be repeated if the user just types return. This is
3864 useful if the command is time-consuming to run, so that accidental
3865 extra keystrokes don't run the same command many times.
3867 * Send break instead of ^C
3869 The standard remote protocol now includes an option to send a break
3870 rather than a ^C to the target in order to interrupt it. By default,
3871 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3873 * Remote protocol timeout
3875 The standard remote protocol includes a new variable `remotetimeout'
3876 that allows you to set the number of seconds before GDB gives up trying
3877 to read from the target. The default value is 2.
3879 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3881 By default GDB will automatically keep track of objects as they are
3882 loaded and unloaded by the dynamic linker. By using the command `set
3883 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3884 when shared library events occur, thus allowing you to set breakpoints
3885 in shared libraries which are explicitly loaded by the inferior.
3887 Note this feature does not work on hpux8. On hpux9 you must link
3888 /usr/lib/end.o into your program. This feature should work
3889 automatically on hpux10.
3891 * Irix 5.x hardware watchpoint support
3893 Irix 5 configurations now support the use of hardware watchpoints.
3895 * Mips protocol "SYN garbage limit"
3897 When debugging a Mips target using the `target mips' protocol, you
3898 may set the number of characters that GDB will ignore by setting
3899 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3900 every character. The default value is 1050.
3902 * Recording and replaying remote debug sessions
3904 If you set `remotelogfile' to the name of a file, gdb will write to it
3905 a recording of a remote debug session. This recording may then be
3906 replayed back to gdb using "gdbreplay". See gdbserver/README for
3907 details. This is useful when you have a problem with GDB while doing
3908 remote debugging; you can make a recording of the session and send it
3909 to someone else, who can then recreate the problem.
3911 * Speedups for remote debugging
3913 GDB includes speedups for downloading and stepping MIPS systems using
3914 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3915 and more efficient S-record downloading.
3917 * Memory use reductions and statistics collection
3919 GDB now uses less memory and reports statistics about memory usage.
3920 Try the `maint print statistics' command, for example.
3922 *** Changes in GDB-4.15:
3924 * Psymtabs for XCOFF
3926 The symbol reader for AIX GDB now uses partial symbol tables. This
3927 can greatly improve startup time, especially for large executables.
3929 * Remote targets use caching
3931 Remote targets now use a data cache to speed up communication with the
3932 remote side. The data cache could lead to incorrect results because
3933 it doesn't know about volatile variables, thus making it impossible to
3934 debug targets which use memory mapped I/O devices. `set remotecache
3935 off' turns the the data cache off.
3937 * Remote targets may have threads
3939 The standard remote protocol now includes support for multiple threads
3940 in the target system, using new protocol commands 'H' and 'T'. See
3941 gdb/remote.c for details.
3945 If GDB is configured with `--enable-netrom', then it will include
3946 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3947 acts as though it is a bank of ROM on the target board, but you can
3948 write into it over the network. GDB's support consists only of
3949 support for fast loading into the emulated ROM; to debug, you must use
3950 another protocol, such as standard remote protocol. The usual
3951 sequence is something like
3953 target nrom <netrom-hostname>
3955 target remote <netrom-hostname>:1235
3959 GDB now includes support for the Apple Macintosh, as a host only. It
3960 may be run as either an MPW tool or as a standalone application, and
3961 it can debug through the serial port. All the usual GDB commands are
3962 available, but to the target command, you must supply "serial" as the
3963 device type instead of "/dev/ttyXX". See mpw-README in the main
3964 directory for more information on how to build. The MPW configuration
3965 scripts */mpw-config.in support only a few targets, and only the
3966 mips-idt-ecoff target has been tested.
3970 GDB configuration now uses autoconf. This is not user-visible,
3971 but does simplify configuration and building.
3975 GDB now supports hpux10.
3977 *** Changes in GDB-4.14:
3979 * New native configurations
3981 x86 FreeBSD i[345]86-*-freebsd
3982 x86 NetBSD i[345]86-*-netbsd
3983 NS32k NetBSD ns32k-*-netbsd
3984 Sparc NetBSD sparc-*-netbsd
3988 A29K VxWorks a29k-*-vxworks
3989 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3990 CPU32 EST-300 emulator m68*-*-est*
3991 PowerPC ELF powerpc-*-elf
3994 * Alpha OSF/1 support for procfs
3996 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3997 possible to attach to running processes. As the mounting of the /proc
3998 filesystem is optional on the Alpha, GDB automatically determines
3999 the availability of /proc during startup. This can lead to problems
4000 if /proc is unmounted after GDB has been started.
4002 * Arguments to user-defined commands
4004 User commands may accept up to 10 arguments separated by whitespace.
4005 Arguments are accessed within the user command via $arg0..$arg9. A
4008 print $arg0 + $arg1 + $arg2
4010 To execute the command use:
4013 Defines the command "adder" which prints the sum of its three arguments.
4014 Note the arguments are text substitutions, so they may reference variables,
4015 use complex expressions, or even perform inferior function calls.
4017 * New `if' and `while' commands
4019 This makes it possible to write more sophisticated user-defined
4020 commands. Both commands take a single argument, which is the
4021 expression to evaluate, and must be followed by the commands to
4022 execute, one per line, if the expression is nonzero, the list being
4023 terminated by the word `end'. The `if' command list may include an
4024 `else' word, which causes the following commands to be executed only
4025 if the expression is zero.
4027 * Fortran source language mode
4029 GDB now includes partial support for Fortran 77. It will recognize
4030 Fortran programs and can evaluate a subset of Fortran expressions, but
4031 variables and functions may not be handled correctly. GDB will work
4032 with G77, but does not yet know much about symbols emitted by other
4035 * Better HPUX support
4037 Most debugging facilities now work on dynamic executables for HPPAs
4038 running hpux9 or later. You can attach to running dynamically linked
4039 processes, but by default the dynamic libraries will be read-only, so
4040 for instance you won't be able to put breakpoints in them. To change
4041 that behavior do the following before running the program:
4047 This will cause the libraries to be mapped private and read-write.
4048 To revert to the normal behavior, do this:
4054 You cannot set breakpoints or examine data in the library until after
4055 the library is loaded if the function/data symbols do not have
4058 GDB can now also read debug symbols produced by the HP C compiler on
4059 HPPAs (sorry, no C++, Fortran or 68k support).
4061 * Target byte order now dynamically selectable
4063 You can choose which byte order to use with a target system, via the
4064 commands "set endian big" and "set endian little", and you can see the
4065 current setting by using "show endian". You can also give the command
4066 "set endian auto", in which case GDB will use the byte order
4067 associated with the executable. Currently, only embedded MIPS
4068 configurations support dynamic selection of target byte order.
4070 * New DOS host serial code
4072 This version uses DPMI interrupts to handle buffered I/O, so you
4073 no longer need to run asynctsr when debugging boards connected to
4076 *** Changes in GDB-4.13:
4078 * New "complete" command
4080 This lists all the possible completions for the rest of the line, if it
4081 were to be given as a command itself. This is intended for use by emacs.
4083 * Trailing space optional in prompt
4085 "set prompt" no longer adds a space for you after the prompt you set. This
4086 allows you to set a prompt which ends in a space or one that does not.
4088 * Breakpoint hit counts
4090 "info break" now displays a count of the number of times the breakpoint
4091 has been hit. This is especially useful in conjunction with "ignore"; you
4092 can ignore a large number of breakpoint hits, look at the breakpoint info
4093 to see how many times the breakpoint was hit, then run again, ignoring one
4094 less than that number, and this will get you quickly to the last hit of
4097 * Ability to stop printing at NULL character
4099 "set print null-stop" will cause GDB to stop printing the characters of
4100 an array when the first NULL is encountered. This is useful when large
4101 arrays actually contain only short strings.
4103 * Shared library breakpoints
4105 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4106 breakpoints in shared libraries before the executable is run.
4108 * Hardware watchpoints
4110 There is a new hardware breakpoint for the watch command for sparclite
4111 targets. See gdb/sparclite/hw_breakpoint.note.
4113 Hardware watchpoints are also now supported under GNU/Linux.
4117 Annotations have been added. These are for use with graphical interfaces,
4118 and are still experimental. Currently only gdba.el uses these.
4120 * Improved Irix 5 support
4122 GDB now works properly with Irix 5.2.
4124 * Improved HPPA support
4126 GDB now works properly with the latest GCC and GAS.
4128 * New native configurations
4130 Sequent PTX4 i[34]86-sequent-ptx4
4131 HPPA running OSF/1 hppa*-*-osf*
4132 Atari TT running SVR4 m68*-*-sysv4*
4133 RS/6000 LynxOS rs6000-*-lynxos*
4137 OS/9000 i[34]86-*-os9k
4138 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4141 * Hitachi SH7000 and E7000-PC ICE support
4143 There is now support for communicating with the Hitachi E7000-PC ICE.
4144 This is available automatically when GDB is configured for the SH.
4148 As usual, a variety of small fixes and improvements, both generic
4149 and configuration-specific. See the ChangeLog for more detail.
4151 *** Changes in GDB-4.12:
4153 * Irix 5 is now supported
4157 GDB-4.12 on the HPPA has a number of changes which make it unable
4158 to debug the output from the currently released versions of GCC and
4159 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4160 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4161 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4164 *** Changes in GDB-4.11:
4166 * User visible changes:
4170 The "set remotedebug" option is now consistent between the mips remote
4171 target, remote targets using the gdb-specific protocol, UDI (AMD's
4172 debug protocol for the 29k) and the 88k bug monitor. It is now an
4173 integer specifying a debug level (normally 0 or 1, but 2 means more
4174 debugging info for the mips target).
4176 * DEC Alpha native support
4178 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4179 debug info, but GDB works fairly well with the DEC compiler and should
4180 work with a future GCC release. See the README file for a few
4181 Alpha-specific notes.
4183 * Preliminary thread implementation
4185 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4187 * LynxOS native and target support for 386
4189 This release has been hosted on LynxOS 2.2, and also can be configured
4190 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4193 * Improvements in C++ mangling/demangling.
4195 This release has much better g++ debugging, specifically in name
4196 mangling/demangling, virtual function calls, print virtual table,
4197 call methods, ...etc.
4199 *** Changes in GDB-4.10:
4201 * User visible changes:
4203 Remote debugging using the GDB-specific (`target remote') protocol now
4204 supports the `load' command. This is only useful if you have some
4205 other way of getting the stub to the target system, and you can put it
4206 somewhere in memory where it won't get clobbered by the download.
4208 Filename completion now works.
4210 When run under emacs mode, the "info line" command now causes the
4211 arrow to point to the line specified. Also, "info line" prints
4212 addresses in symbolic form (as well as hex).
4214 All vxworks based targets now support a user settable option, called
4215 vxworks-timeout. This option represents the number of seconds gdb
4216 should wait for responses to rpc's. You might want to use this if
4217 your vxworks target is, perhaps, a slow software simulator or happens
4218 to be on the far side of a thin network line.
4222 This release contains support for using a DEC alpha as a GDB host for
4223 cross debugging. Native alpha debugging is not supported yet.
4226 *** Changes in GDB-4.9:
4230 This is the first GDB release which is accompanied by a matching testsuite.
4231 The testsuite requires installation of dejagnu, which should be available
4232 via ftp from most sites that carry GNU software.
4236 'Cfront' style demangling has had its name changed to 'ARM' style, to
4237 emphasize that it was written from the specifications in the C++ Annotated
4238 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4239 disclaimers, it still generated too much confusion with users attempting to
4240 use gdb with AT&T cfront.
4244 GDB now uses a standard remote interface to a simulator library.
4245 So far, the library contains simulators for the Zilog Z8001/2, the
4246 Hitachi H8/300, H8/500 and Super-H.
4248 * New targets supported
4250 H8/300 simulator h8300-hitachi-hms or h8300hms
4251 H8/500 simulator h8500-hitachi-hms or h8500hms
4252 SH simulator sh-hitachi-hms or sh
4253 Z8000 simulator z8k-zilog-none or z8ksim
4254 IDT MIPS board over serial line mips-idt-ecoff
4256 Cross-debugging to GO32 targets is supported. It requires a custom
4257 version of the i386-stub.c module which is integrated with the
4258 GO32 memory extender.
4260 * New remote protocols
4262 MIPS remote debugging protocol.
4264 * New source languages supported
4266 This version includes preliminary support for Chill, a Pascal like language
4267 used by telecommunications companies. Chill support is also being integrated
4268 into the GNU compiler, but we don't know when it will be publically available.
4271 *** Changes in GDB-4.8:
4273 * HP Precision Architecture supported
4275 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4276 version of this support was available as a set of patches from the
4277 University of Utah. GDB does not support debugging of programs
4278 compiled with the HP compiler, because HP will not document their file
4279 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4280 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4282 Many problems in the preliminary version have been fixed.
4284 * Faster and better demangling
4286 We have improved template demangling and fixed numerous bugs in the GNU style
4287 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4288 character types (wchar_t) are now supported. Demangling of each symbol is now
4289 only done once, and is cached when the symbol table for a file is read in.
4290 This results in a small increase in memory usage for C programs, a moderate
4291 increase in memory usage for C++ programs, and a fantastic speedup in
4294 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4295 from the specifications in the Annotated Reference Manual, which AT&T's
4296 compiler does not actually implement.
4298 * G++ multiple inheritance compiler problem
4300 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4301 inheritance lattices was reworked to properly discover ambiguities. We
4302 recently found an example which causes this new algorithm to fail in a
4303 very subtle way, producing bad debug information for those classes.
4304 The file 'gcc.patch' (in this directory) can be applied to gcc to
4305 circumvent the problem. A future GCC release will contain a complete
4308 The previous G++ debug info problem (mentioned below for the gdb-4.7
4309 release) is fixed in gcc version 2.3.2.
4311 * Improved configure script
4313 The `configure' script will now attempt to guess your system type if
4314 you don't supply a host system type. The old scheme of supplying a
4315 host system triplet is preferable over using this. All the magic is
4316 done in the new `config.guess' script. Examine it for details.
4318 We have also brought our configure script much more in line with the FSF's
4319 version. It now supports the --with-xxx options. In particular,
4320 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4321 The resulting GDB will not be able to read arbitrary object file formats --
4322 only the format ``expected'' to be used on the configured target system.
4323 We hope to make this the default in a future release.
4325 * Documentation improvements
4327 There's new internal documentation on how to modify GDB, and how to
4328 produce clean changes to the code. We implore people to read it
4329 before submitting changes.
4331 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4332 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4333 `info' files are also provided. To build `info' files from scratch,
4334 you will need the latest `makeinfo' release, which will be available in
4335 a future texinfo-X.Y release.
4337 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4338 We're not sure exactly which versions have this problem, but it has
4339 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4340 or better. If that isn't possible, there is a patch in
4341 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4342 around this problem.
4346 GDB now supports array constants that can be used in expressions typed in by
4347 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4348 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4351 The new directory `gdb/sparclite' contains a program that demonstrates
4352 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4354 * New native hosts supported
4356 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4357 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4359 * New targets supported
4361 AMD 29k family via UDI a29k-amd-udi or udi29k
4363 * New file formats supported
4365 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4366 HPUX core files, and SCO 3.2v2 core files.
4370 Attaching to processes now works again; thanks for the many bug reports.
4372 We have also stomped on a bunch of core dumps caused by
4373 printf_filtered("%s") problems.
4375 We eliminated a copyright problem on the rpc and ptrace header files
4376 for VxWorks, which was discovered at the last minute during the 4.7
4377 release. You should now be able to build a VxWorks GDB.
4379 You can now interrupt gdb while an attached process is running. This
4380 will cause the attached process to stop, and give control back to GDB.
4382 We fixed problems caused by using too many file descriptors
4383 for reading symbols from object files and libraries. This was
4384 especially a problem for programs that used many (~100) shared
4387 The `step' command now only enters a subroutine if there is line number
4388 information for the subroutine. Otherwise it acts like the `next'
4389 command. Previously, `step' would enter subroutines if there was
4390 any debugging information about the routine. This avoids problems
4391 when using `cc -g1' on MIPS machines.
4393 * Internal improvements
4395 GDB's internal interfaces have been improved to make it easier to support
4396 debugging of multiple languages in the future.
4398 GDB now uses a common structure for symbol information internally.
4399 Minimal symbols (derived from linkage symbols in object files), partial
4400 symbols (from a quick scan of debug information), and full symbols
4401 contain a common subset of information, making it easier to write
4402 shared code that handles any of them.
4404 * New command line options
4406 We now accept --silent as an alias for --quiet.
4410 The memory-mapped-malloc library is now licensed under the GNU Library
4411 General Public License.
4413 *** Changes in GDB-4.7:
4415 * Host/native/target split
4417 GDB has had some major internal surgery to untangle the support for
4418 hosts and remote targets. Now, when you configure GDB for a remote
4419 target, it will no longer load in all of the support for debugging
4420 local programs on the host. When fully completed and tested, this will
4421 ensure that arbitrary host/target combinations are possible.
4423 The primary conceptual shift is to separate the non-portable code in
4424 GDB into three categories. Host specific code is required any time GDB
4425 is compiled on that host, regardless of the target. Target specific
4426 code relates to the peculiarities of the target, but can be compiled on
4427 any host. Native specific code is everything else: it can only be
4428 built when the host and target are the same system. Child process
4429 handling and core file support are two common `native' examples.
4431 GDB's use of /proc for controlling Unix child processes is now cleaner.
4432 It has been split out into a single module under the `target_ops' vector,
4433 plus two native-dependent functions for each system that uses /proc.
4435 * New hosts supported
4437 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4438 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4439 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4441 * New targets supported
4443 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4444 68030 and CPU32 m68030-*-*, m68332-*-*
4446 * New native hosts supported
4448 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4449 (386bsd is not well tested yet)
4450 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4452 * New file formats supported
4454 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4455 supports reading of `a.out.adobe' object files, which are an a.out
4456 format extended with minimal information about multiple sections.
4460 `show copying' is the same as the old `info copying'.
4461 `show warranty' is the same as `info warrantee'.
4462 These were renamed for consistency. The old commands continue to work.
4464 `info handle' is a new alias for `info signals'.
4466 You can now define pre-command hooks, which attach arbitrary command
4467 scripts to any command. The commands in the hook will be executed
4468 prior to the user's command. You can also create a hook which will be
4469 executed whenever the program stops. See gdb.texinfo.
4473 We now deal with Cfront style name mangling, and can even extract type
4474 info from mangled symbols. GDB can automatically figure out which
4475 symbol mangling style your C++ compiler uses.
4477 Calling of methods and virtual functions has been improved as well.
4481 The crash that occured when debugging Sun Ansi-C compiled binaries is
4482 fixed. This was due to mishandling of the extra N_SO stabs output
4485 We also finally got Ultrix 4.2 running in house, and fixed core file
4486 support, with help from a dozen people on the net.
4488 John M. Farrell discovered that the reason that single-stepping was so
4489 slow on all of the Mips based platforms (primarily SGI and DEC) was
4490 that we were trying to demangle and lookup a symbol used for internal
4491 purposes on every instruction that was being stepped through. Changing
4492 the name of that symbol so that it couldn't be mistaken for a C++
4493 mangled symbol sped things up a great deal.
4495 Rich Pixley sped up symbol lookups in general by getting much smarter
4496 about when C++ symbol mangling is necessary. This should make symbol
4497 completion (TAB on the command line) much faster. It's not as fast as
4498 we'd like, but it's significantly faster than gdb-4.6.
4502 A new user controllable variable 'call_scratch_address' can
4503 specify the location of a scratch area to be used when GDB
4504 calls a function in the target. This is necessary because the
4505 usual method of putting the scratch area on the stack does not work
4506 in systems that have separate instruction and data spaces.
4508 We integrated changes to support the 29k UDI (Universal Debugger
4509 Interface), but discovered at the last minute that we didn't have all
4510 of the appropriate copyright paperwork. We are working with AMD to
4511 resolve this, and hope to have it available soon.
4515 We have sped up the remote serial line protocol, especially for targets
4516 with lots of registers. It now supports a new `expedited status' ('T')
4517 message which can be used in place of the existing 'S' status message.
4518 This allows the remote stub to send only the registers that GDB
4519 needs to make a quick decision about single-stepping or conditional
4520 breakpoints, eliminating the need to fetch the entire register set for
4521 each instruction being stepped through.
4523 The GDB remote serial protocol now implements a write-through cache for
4524 registers, only re-reading the registers if the target has run.
4526 There is also a new remote serial stub for SPARC processors. You can
4527 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4528 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4529 processor with a serial port.
4533 Configure.in files have become much easier to read and modify. A new
4534 `table driven' format makes it more obvious what configurations are
4535 supported, and what files each one uses.
4539 There is a new opcodes library which will eventually contain all of the
4540 disassembly routines and opcode tables. At present, it only contains
4541 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4542 disassembler (binutils/objdump) to share these routines.
4544 The libiberty library is now copylefted under the GNU Library General
4545 Public License. This allows more liberal use, and was done so libg++
4546 can use it. This makes no difference to GDB, since the Library License
4547 grants all the rights from the General Public License.
4551 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4552 reference to the stabs symbol info used by the debugger. It is (as far
4553 as we know) the only published document on this fascinating topic. We
4554 encourage you to read it, compare it to the stabs information on your
4555 system, and send improvements on the document in general (to
4556 bug-gdb@prep.ai.mit.edu).
4558 And, of course, many bugs have been fixed.
4561 *** Changes in GDB-4.6:
4563 * Better support for C++ function names
4565 GDB now accepts as input the "demangled form" of C++ overloaded function
4566 names and member function names, and can do command completion on such names
4567 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4568 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4569 Make use of command completion, it is your friend.
4571 GDB also now accepts a variety of C++ mangled symbol formats. They are
4572 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4573 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4574 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4575 for the list of formats.
4577 * G++ symbol mangling problem
4579 Recent versions of gcc have a bug in how they emit debugging information for
4580 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4581 directory) can be applied to gcc to fix the problem. Alternatively, if you
4582 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4583 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4584 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4587 * New 'maintenance' command
4589 All of the commands related to hacking GDB internals have been moved out of
4590 the main command set, and now live behind the 'maintenance' command. This
4591 can also be abbreviated as 'mt'. The following changes were made:
4593 dump-me -> maintenance dump-me
4594 info all-breakpoints -> maintenance info breakpoints
4595 printmsyms -> maintenance print msyms
4596 printobjfiles -> maintenance print objfiles
4597 printpsyms -> maintenance print psymbols
4598 printsyms -> maintenance print symbols
4600 The following commands are new:
4602 maintenance demangle Call internal GDB demangler routine to
4603 demangle a C++ link name and prints the result.
4604 maintenance print type Print a type chain for a given symbol
4606 * Change to .gdbinit file processing
4608 We now read the $HOME/.gdbinit file before processing the argv arguments
4609 (e.g. reading symbol files or core files). This allows global parameters to
4610 be set, which will apply during the symbol reading. The ./.gdbinit is still
4611 read after argv processing.
4613 * New hosts supported
4615 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4617 GNU/Linux support i386-unknown-linux or linux
4619 We are also including code to support the HP/PA running BSD and HPUX. This
4620 is almost guaranteed not to work, as we didn't have time to test or build it
4621 for this release. We are including it so that the more adventurous (or
4622 masochistic) of you can play with it. We also had major problems with the
4623 fact that the compiler that we got from HP doesn't support the -g option.
4626 * New targets supported
4628 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4630 * More smarts about finding #include files
4632 GDB now remembers the compilation directory for all include files, and for
4633 all files from which C is generated (like yacc and lex sources). This
4634 greatly improves GDB's ability to find yacc/lex sources, and include files,
4635 especially if you are debugging your program from a directory different from
4636 the one that contains your sources.
4638 We also fixed a bug which caused difficulty with listing and setting
4639 breakpoints in include files which contain C code. (In the past, you had to
4640 try twice in order to list an include file that you hadn't looked at before.)
4642 * Interesting infernals change
4644 GDB now deals with arbitrary numbers of sections, where the symbols for each
4645 section must be relocated relative to that section's landing place in the
4646 target's address space. This work was needed to support ELF with embedded
4647 stabs used by Solaris-2.0.
4649 * Bug fixes (of course!)
4651 There have been loads of fixes for the following things:
4652 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4653 i960, stabs, DOS(GO32), procfs, etc...
4655 See the ChangeLog for details.
4657 *** Changes in GDB-4.5:
4659 * New machines supported (host and target)
4661 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4663 SGI Irix-4.x mips-sgi-irix4 or iris4
4665 * New malloc package
4667 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4668 Mmalloc is capable of handling mutiple heaps of memory. It is also
4669 capable of saving a heap to a file, and then mapping it back in later.
4670 This can be used to greatly speedup the startup of GDB by using a
4671 pre-parsed symbol table which lives in a mmalloc managed heap. For
4672 more details, please read mmalloc/mmalloc.texi.
4676 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4677 'help info proc' for details.
4679 * MIPS ecoff symbol table format
4681 The code that reads MIPS symbol table format is now supported on all hosts.
4682 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4685 * File name changes for MS-DOS
4687 Many files in the config directories have been renamed to make it easier to
4688 support GDB on MS-DOSe systems (which have very restrictive file name
4689 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4690 environment) is close to working but has some remaining problems. Note
4691 that debugging of DOS programs is not supported, due to limitations
4692 in the ``operating system'', but it can be used to host cross-debugging.
4694 * Cross byte order fixes
4696 Many fixes have been made to support cross debugging of Sparc and MIPS
4697 targets from hosts whose byte order differs.
4699 * New -mapped and -readnow options
4701 If memory-mapped files are available on your system through the 'mmap'
4702 system call, you can use the -mapped option on the `file' or
4703 `symbol-file' commands to cause GDB to write the symbols from your
4704 program into a reusable file. If the program you are debugging is
4705 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4706 Future GDB debugging sessions will notice the presence of this file,
4707 and will quickly map in symbol information from it, rather than reading
4708 the symbol table from the executable program. Using the '-mapped'
4709 option in a GDB `file' or `symbol-file' command has the same effect as
4710 starting GDB with the '-mapped' command-line option.
4712 You can cause GDB to read the entire symbol table immediately by using
4713 the '-readnow' option with any of the commands that load symbol table
4714 information (or on the GDB command line). This makes the command
4715 slower, but makes future operations faster.
4717 The -mapped and -readnow options are typically combined in order to
4718 build a `fred.syms' file that contains complete symbol information.
4719 A simple GDB invocation to do nothing but build a `.syms' file for future
4722 gdb -batch -nx -mapped -readnow programname
4724 The `.syms' file is specific to the host machine on which GDB is run.
4725 It holds an exact image of GDB's internal symbol table. It cannot be
4726 shared across multiple host platforms.
4728 * longjmp() handling
4730 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4731 siglongjmp() without losing control. This feature has not yet been ported to
4732 all systems. It currently works on many 386 platforms, all MIPS-based
4733 platforms (SGI, DECstation, etc), and Sun3/4.
4737 Preliminary work has been put in to support the new Solaris OS from Sun. At
4738 this time, it can control and debug processes, but it is not capable of
4743 As always, many many bug fixes. The major areas were with g++, and mipsread.
4744 People using the MIPS-based platforms should experience fewer mysterious
4745 crashes and trashed symbol tables.
4747 *** Changes in GDB-4.4:
4749 * New machines supported (host and target)
4751 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4753 BSD Reno on Vax vax-dec-bsd
4754 Ultrix on Vax vax-dec-ultrix
4756 * New machines supported (target)
4758 AMD 29000 embedded, using EBMON a29k-none-none
4762 GDB continues to improve its handling of C++. `References' work better.
4763 The demangler has also been improved, and now deals with symbols mangled as
4764 per the Annotated C++ Reference Guide.
4766 GDB also now handles `stabs' symbol information embedded in MIPS
4767 `ecoff' symbol tables. Since the ecoff format was not easily
4768 extensible to handle new languages such as C++, this appeared to be a
4769 good way to put C++ debugging info into MIPS binaries. This option
4770 will be supported in the GNU C compiler, version 2, when it is
4773 * New features for SVR4
4775 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4776 shared libraries. Debugging dynamically linked programs should present
4777 only minor differences from debugging statically linked programs.
4779 The `info proc' command will print out information about any process
4780 on an SVR4 system (including the one you are debugging). At the moment,
4781 it prints the address mappings of the process.
4783 If you bring up GDB on another SVR4 system, please send mail to
4784 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4786 * Better dynamic linking support in SunOS
4788 Reading symbols from shared libraries which contain debugging symbols
4789 now works properly. However, there remain issues such as automatic
4790 skipping of `transfer vector' code during function calls, which
4791 make it harder to debug code in a shared library, than to debug the
4792 same code linked statically.
4796 GDB is now using the latest `getopt' routines from the FSF. This
4797 version accepts the -- prefix for options with long names. GDB will
4798 continue to accept the old forms (-option and +option) as well.
4799 Various single letter abbreviations for options have been explicity
4800 added to the option table so that they won't get overshadowed in the
4801 future by other options that begin with the same letter.
4805 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4806 Many assorted bugs have been handled. Many more remain to be handled.
4807 See the various ChangeLog files (primarily in gdb and bfd) for details.
4810 *** Changes in GDB-4.3:
4812 * New machines supported (host and target)
4814 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4815 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4816 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4818 * Almost SCO Unix support
4820 We had hoped to support:
4821 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4822 (except for core file support), but we discovered very late in the release
4823 that it has problems with process groups that render gdb unusable. Sorry
4824 about that. I encourage people to fix it and post the fixes.
4826 * Preliminary ELF and DWARF support
4828 GDB can read ELF object files on System V Release 4, and can handle
4829 debugging records for C, in DWARF format, in ELF files. This support
4830 is preliminary. If you bring up GDB on another SVR4 system, please
4831 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4836 GDB now uses the latest `readline' library. One user-visible change
4837 is that two tabs will list possible command completions, which previously
4838 required typing M-? (meta-question mark, or ESC ?).
4842 The `stepi' bug that many of you noticed has been squashed.
4843 Many bugs in C++ have been handled. Many more remain to be handled.
4844 See the various ChangeLog files (primarily in gdb and bfd) for details.
4846 * State of the MIPS world (in case you wondered):
4848 GDB can understand the symbol tables emitted by the compilers
4849 supplied by most vendors of MIPS-based machines, including DEC. These
4850 symbol tables are in a format that essentially nobody else uses.
4852 Some versions of gcc come with an assembler post-processor called
4853 mips-tfile. This program is required if you want to do source-level
4854 debugging of gcc-compiled programs. I believe FSF does not ship
4855 mips-tfile with gcc version 1, but it will eventually come with gcc
4858 Debugging of g++ output remains a problem. g++ version 1.xx does not
4859 really support it at all. (If you're lucky, you should be able to get
4860 line numbers and stack traces to work, but no parameters or local
4861 variables.) With some work it should be possible to improve the
4864 When gcc version 2 is released, you will have somewhat better luck.
4865 However, even then you will get confusing results for inheritance and
4868 We will eventually provide full debugging of g++ output on
4869 DECstations. This will probably involve some kind of stabs-in-ecoff
4870 encapulation, but the details have not been worked out yet.
4873 *** Changes in GDB-4.2:
4875 * Improved configuration
4877 Only one copy of `configure' exists now, and it is not self-modifying.
4878 Porting BFD is simpler.
4882 The `step' and `next' commands now only stop at the first instruction
4883 of a source line. This prevents the multiple stops that used to occur
4884 in switch statements, for-loops, etc. `Step' continues to stop if a
4885 function that has debugging information is called within the line.
4889 Lots of small bugs fixed. More remain.
4891 * New host supported (not target)
4893 Intel 386 PC clone running Mach i386-none-mach
4896 *** Changes in GDB-4.1:
4898 * Multiple source language support
4900 GDB now has internal scaffolding to handle several source languages.
4901 It determines the type of each source file from its filename extension,
4902 and will switch expression parsing and number formatting to match the
4903 language of the function in the currently selected stack frame.
4904 You can also specifically set the language to be used, with
4905 `set language c' or `set language modula-2'.
4909 GDB now has preliminary support for the GNU Modula-2 compiler,
4910 currently under development at the State University of New York at
4911 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4912 continue through the fall of 1991 and into 1992.
4914 Other Modula-2 compilers are currently not supported, and attempting to
4915 debug programs compiled with them will likely result in an error as the
4916 symbol table is read. Feel free to work on it, though!
4918 There are hooks in GDB for strict type checking and range checking,
4919 in the `Modula-2 philosophy', but they do not currently work.
4923 GDB can now write to executable and core files (e.g. patch
4924 a variable's value). You must turn this switch on, specify
4925 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4926 by assigning a new value to a variable. Modifications take
4929 * Automatic SunOS shared library reading
4931 When you run your program, GDB automatically determines where its
4932 shared libraries (if any) have been loaded, and reads their symbols.
4933 The `share' command is no longer needed. This also works when
4934 examining core files.
4938 You can specify the number of lines that the `list' command shows.
4941 * New machines supported (host and target)
4943 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4944 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4945 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4947 * New hosts supported (not targets)
4949 IBM RT/PC: romp-ibm-aix or rtpc
4951 * New targets supported (not hosts)
4953 AMD 29000 embedded with COFF a29k-none-coff
4954 AMD 29000 embedded with a.out a29k-none-aout
4955 Ultracomputer remote kernel debug a29k-nyu-kern
4957 * New remote interfaces
4963 *** Changes in GDB-4.0:
4967 Wide output is wrapped at good places to make the output more readable.
4969 Gdb now supports cross-debugging from a host machine of one type to a
4970 target machine of another type. Communication with the target system
4971 is over serial lines. The ``target'' command handles connecting to the
4972 remote system; the ``load'' command will download a program into the
4973 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4974 also supports debugging of realtime processes running under VxWorks,
4975 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4976 stub on the target system.
4978 New CPUs supported include the AMD 29000 and Intel 960.
4980 GDB now reads object files and symbol tables via a ``binary file''
4981 library, which allows a single copy of GDB to debug programs of multiple
4982 object file types such as a.out and coff.
4984 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4985 refcard.dvi and refcard.ps are available to format it).
4988 * Control-Variable user interface simplified
4990 All variables that control the operation of the debugger can be set
4991 by the ``set'' command, and displayed by the ``show'' command.
4993 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4994 ``Show prompt'' produces the response:
4995 Gdb's prompt is new-gdb=>.
4997 What follows are the NEW set commands. The command ``help set'' will
4998 print a complete list of old and new set commands. ``help set FOO''
4999 will give a longer description of the variable FOO. ``show'' will show
5000 all of the variable descriptions and their current settings.
5002 confirm on/off: Enables warning questions for operations that are
5003 hard to recover from, e.g. rerunning the program while
5004 it is already running. Default is ON.
5006 editing on/off: Enables EMACS style command line editing
5007 of input. Previous lines can be recalled with
5008 control-P, the current line can be edited with control-B,
5009 you can search for commands with control-R, etc.
5012 history filename NAME: NAME is where the gdb command history
5013 will be stored. The default is .gdb_history,
5014 or the value of the environment variable
5017 history size N: The size, in commands, of the command history. The
5018 default is 256, or the value of the environment variable
5021 history save on/off: If this value is set to ON, the history file will
5022 be saved after exiting gdb. If set to OFF, the
5023 file will not be saved. The default is OFF.
5025 history expansion on/off: If this value is set to ON, then csh-like
5026 history expansion will be performed on
5027 command line input. The default is OFF.
5029 radix N: Sets the default radix for input and output. It can be set
5030 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5031 in the current radix, so "set radix 10" is always a no-op.
5033 height N: This integer value is the number of lines on a page. Default
5034 is 24, the current `stty rows'' setting, or the ``li#''
5035 setting from the termcap entry matching the environment
5038 width N: This integer value is the number of characters on a line.
5039 Default is 80, the current `stty cols'' setting, or the ``co#''
5040 setting from the termcap entry matching the environment
5043 Note: ``set screensize'' is obsolete. Use ``set height'' and
5044 ``set width'' instead.
5046 print address on/off: Print memory addresses in various command displays,
5047 such as stack traces and structure values. Gdb looks
5048 more ``symbolic'' if you turn this off; it looks more
5049 ``machine level'' with it on. Default is ON.
5051 print array on/off: Prettyprint arrays. New convenient format! Default
5054 print demangle on/off: Print C++ symbols in "source" form if on,
5057 print asm-demangle on/off: Same, for assembler level printouts
5060 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5063 * Support for Epoch Environment.
5065 The epoch environment is a version of Emacs v18 with windowing. One
5066 new command, ``inspect'', is identical to ``print'', except that if you
5067 are running in the epoch environment, the value is printed in its own
5071 * Support for Shared Libraries
5073 GDB can now debug programs and core files that use SunOS shared libraries.
5074 Symbols from a shared library cannot be referenced
5075 before the shared library has been linked with the program (this
5076 happens after you type ``run'' and before the function main() is entered).
5077 At any time after this linking (including when examining core files
5078 from dynamically linked programs), gdb reads the symbols from each
5079 shared library when you type the ``sharedlibrary'' command.
5080 It can be abbreviated ``share''.
5082 sharedlibrary REGEXP: Load shared object library symbols for files
5083 matching a unix regular expression. No argument
5084 indicates to load symbols for all shared libraries.
5086 info sharedlibrary: Status of loaded shared libraries.
5091 A watchpoint stops execution of a program whenever the value of an
5092 expression changes. Checking for this slows down execution
5093 tremendously whenever you are in the scope of the expression, but is
5094 quite useful for catching tough ``bit-spreader'' or pointer misuse
5095 problems. Some machines such as the 386 have hardware for doing this
5096 more quickly, and future versions of gdb will use this hardware.
5098 watch EXP: Set a watchpoint (breakpoint) for an expression.
5100 info watchpoints: Information about your watchpoints.
5102 delete N: Deletes watchpoint number N (same as breakpoints).
5103 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5104 enable N: Re-enables watchpoint number N (same as breakpoints).
5107 * C++ multiple inheritance
5109 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5112 * C++ exception handling
5114 Gdb now supports limited C++ exception handling. Besides the existing
5115 ability to breakpoint on an exception handler, gdb can breakpoint on
5116 the raising of an exception (before the stack is peeled back to the
5119 catch FOO: If there is a FOO exception handler in the dynamic scope,
5120 set a breakpoint to catch exceptions which may be raised there.
5121 Multiple exceptions (``catch foo bar baz'') may be caught.
5123 info catch: Lists all exceptions which may be caught in the
5124 current stack frame.
5127 * Minor command changes
5129 The command ``call func (arg, arg, ...)'' now acts like the print
5130 command, except it does not print or save a value if the function's result
5131 is void. This is similar to dbx usage.
5133 The ``up'' and ``down'' commands now always print the frame they end up
5134 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5135 frames without printing.
5137 * New directory command
5139 'dir' now adds directories to the FRONT of the source search path.
5140 The path starts off empty. Source files that contain debug information
5141 about the directory in which they were compiled can be found even
5142 with an empty path; Sun CC and GCC include this information. If GDB can't
5143 find your source file in the current directory, type "dir .".
5145 * Configuring GDB for compilation
5147 For normal use, type ``./configure host''. See README or gdb.texinfo
5150 GDB now handles cross debugging. If you are remotely debugging between
5151 two different machines, type ``./configure host -target=targ''.
5152 Host is the machine where GDB will run; targ is the machine
5153 where the program that you are debugging will run.