1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.5
8 ** Vectors can be created with gdb.Type.vector.
10 * New Python-based convenience functions:
12 ** $_memeq(buf1, buf2, length)
13 ** $_streq(str1, str2)
15 ** $_regex(str, regex)
17 * The 'cd' command now defaults to using '~' (the home directory) if not
20 * New configure options
22 --enable-libmcheck/--disable-libmcheck
23 By default, development versions are built with -lmcheck on hosts
24 that support it, in order to help track memory corruption issues.
25 Release versions, on the other hand, are built without -lmcheck
26 by default. The --enable-libmcheck/--disable-libmcheck configure
27 options allow the user to override that default.
29 * New commands (for set/show, see "New options" below)
32 List the BFDs known to GDB.
34 python-interactive [command]
36 Start a Python interactive prompt, or evaluate the optional command
37 and print the result of expressions.
40 "py" is a new alias for "python".
44 ** For the Renesas Super-H architecture, the "regs" command has been removed
45 (has been deprecated in GDB 7.5), and "info all-registers" should be used
50 ** Command parameter changes are now notified using new async record
52 ** Trace frame changes caused by command "tfind" are now notified using
53 new async record "=traceframe-changed".
54 ** The creation and deletion of trace state variables are now notified
55 using new async records "=tsv-created" and "=tsv-deleted".
57 *** Changes in GDB 7.5
59 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
60 for more x32 ABI info.
62 * GDB now supports access to MIPS DSP registers on Linux targets.
64 * GDB now supports debugging microMIPS binaries.
66 * The "info os" command on GNU/Linux can now display information on
67 several new classes of objects managed by the operating system:
68 "info os procgroups" lists process groups
69 "info os files" lists file descriptors
70 "info os sockets" lists internet-domain sockets
71 "info os shm" lists shared-memory regions
72 "info os semaphores" lists semaphores
73 "info os msg" lists message queues
74 "info os modules" lists loaded kernel modules
76 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
77 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
78 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
79 options and inspect the probe arguments using the new $_probe_arg family
80 of convenience variables. You can obtain more information about SystemTap
81 in <http://sourceware.org/systemtap/>.
83 * GDB now supports reversible debugging on ARM, it allows you to
84 debug basic ARM and THUMB instructions, and provides
85 record/replay support.
87 * The option "symbol-reloading" has been deleted as it is no longer used.
91 ** GDB commands implemented in Python can now be put in command class
94 ** The "maint set python print-stack on|off" is now deleted.
96 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
97 apply "flag enum"-style pretty-printing to any enum.
99 ** gdb.lookup_symbol can now work when there is no current frame.
101 ** gdb.Symbol now has a 'line' attribute, holding the line number in
102 the source at which the symbol was defined.
104 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
105 method 'value'. The former indicates whether the symbol needs a
106 frame in order to compute its value, and the latter computes the
109 ** A new method 'referenced_value' on gdb.Value objects which can
110 dereference pointer as well as C++ reference values.
112 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
113 which return the global and static blocks (as gdb.Block objects),
114 of the underlying symbol table, respectively.
116 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
117 object associated with a PC value.
119 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
120 of the address range occupied by code for the current source line.
122 * Go language support.
123 GDB now supports debugging programs written in the Go programming
126 * GDBserver now supports stdio connections.
127 E.g. (gdb) target remote | ssh myhost gdbserver - hello
129 * The binary "gdbtui" can no longer be built or installed.
130 Use "gdb -tui" instead.
132 * GDB will now print "flag" enums specially. A flag enum is one where
133 all the enumerator values have no bits in common when pairwise
134 "and"ed. When printing a value whose type is a flag enum, GDB will
135 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
136 (gdb) print (enum E) 3
139 * The filename part of a linespec will now match trailing components
140 of a source file name. For example, "break gcc/expr.c:1000" will
141 now set a breakpoint in build/gcc/expr.c, but not
144 * The "info proc" and "generate-core-file" commands will now also
145 work on remote targets connected to GDBserver on Linux.
147 * The command "info catch" has been removed. It has been disabled
150 * The "catch exception" and "catch assert" commands now accept
151 a condition at the end of the command, much like the "break"
152 command does. For instance:
154 (gdb) catch exception Constraint_Error if Barrier = True
156 Previously, it was possible to add a condition to such catchpoints,
157 but it had to be done as a second step, after the catchpoint had been
158 created, using the "condition" command.
160 * The "info static-tracepoint-marker" command will now also work on
161 native Linux targets with in-process agent.
163 * GDB can now set breakpoints on inlined functions.
165 * The .gdb_index section has been updated to include symbols for
166 inlined functions. GDB will ignore older .gdb_index sections by
167 default, which could cause symbol files to be loaded more slowly
168 until their .gdb_index sections can be recreated. The new command
169 "set use-deprecated-index-sections on" will cause GDB to use any older
170 .gdb_index sections it finds. This will restore performance, but the
171 ability to set breakpoints on inlined functions will be lost in symbol
172 files with older .gdb_index sections.
174 The .gdb_index section has also been updated to record more information
175 about each symbol. This speeds up the "info variables", "info functions"
176 and "info types" commands when used with programs having the .gdb_index
177 section, as well as speeding up debugging with shared libraries using
178 the .gdb_index section.
180 * Ada support for GDB/MI Variable Objects has been added.
182 * GDB can now support 'breakpoint always-inserted mode' in 'record'
187 ** New command -info-os is the MI equivalent of "info os".
189 ** Output logs ("set logging" and related) now include MI output.
193 ** "set use-deprecated-index-sections on|off"
194 "show use-deprecated-index-sections on|off"
195 Controls the use of deprecated .gdb_index sections.
197 ** "catch load" and "catch unload" can be used to stop when a shared
198 library is loaded or unloaded, respectively.
200 ** "enable count" can be used to auto-disable a breakpoint after
203 ** "info vtbl" can be used to show the virtual method tables for
204 C++ and Java objects.
206 ** "explore" and its sub commands "explore value" and "explore type"
207 can be used to reccursively explore values and types of
208 expressions. These commands are available only if GDB is
209 configured with '--with-python'.
211 ** "info auto-load" shows status of all kinds of auto-loaded files,
212 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
213 sequences of commands files, "info auto-load python-scripts"
214 shows status of auto-loading Python script files,
215 "info auto-load local-gdbinit" shows status of loading init file
216 (.gdbinit) from current directory and "info auto-load libthread-db" shows
217 status of inferior specific thread debugging shared library loading.
219 ** "info auto-load-scripts", "set auto-load-scripts on|off"
220 and "show auto-load-scripts" commands have been deprecated, use their
221 "info auto-load python-scripts", "set auto-load python-scripts on|off"
222 and "show auto-load python-scripts" counterparts instead.
224 ** "dprintf location,format,args..." creates a dynamic printf, which
225 is basically a breakpoint that does a printf and immediately
226 resumes your program's execution, so it is like a printf that you
227 can insert dynamically at runtime instead of at compiletime.
229 ** "set print symbol"
231 Controls whether GDB attempts to display the symbol, if any,
232 corresponding to addresses it prints. This defaults to "on", but
233 you can set it to "off" to restore GDB's previous behavior.
235 * Deprecated commands
237 ** For the Renesas Super-H architecture, the "regs" command has been
238 deprecated, and "info all-registers" should be used instead.
242 Renesas RL78 rl78-*-elf
243 HP OpenVMS ia64 ia64-hp-openvms*
245 * GDBserver supports evaluation of breakpoint conditions. When
246 support is advertised by GDBserver, GDB may be told to send the
247 breakpoint conditions in bytecode form to GDBserver. GDBserver
248 will only report the breakpoint trigger to GDB when its condition
254 show mips compression
255 Select the compressed ISA encoding used in functions that have no symbol
256 information available. The encoding can be set to either of:
259 and is updated automatically from ELF file flags if available.
261 set breakpoint condition-evaluation
262 show breakpoint condition-evaluation
263 Control whether breakpoint conditions are evaluated by GDB ("host") or by
264 GDBserver ("target"). Default option "auto" chooses the most efficient
266 This option can improve debugger efficiency depending on the speed of the
270 Disable auto-loading globally.
273 Show auto-loading setting of all kinds of auto-loaded files.
275 set auto-load gdb-scripts on|off
276 show auto-load gdb-scripts
277 Control auto-loading of GDB canned sequences of commands files.
279 set auto-load python-scripts on|off
280 show auto-load python-scripts
281 Control auto-loading of Python script files.
283 set auto-load local-gdbinit on|off
284 show auto-load local-gdbinit
285 Control loading of init file (.gdbinit) from current directory.
287 set auto-load libthread-db on|off
288 show auto-load libthread-db
289 Control auto-loading of inferior specific thread debugging shared library.
291 set auto-load scripts-directory <dir1>[:<dir2>...]
292 show auto-load scripts-directory
293 Set a list of directories from which to load auto-loaded scripts.
294 Automatically loaded Python scripts and GDB scripts are located in one
295 of the directories listed by this option.
296 The delimiter (':' above) may differ according to the host platform.
298 set auto-load safe-path <dir1>[:<dir2>...]
299 show auto-load safe-path
300 Set a list of directories from which it is safe to auto-load files.
301 The delimiter (':' above) may differ according to the host platform.
303 set debug auto-load on|off
305 Control display of debugging info for auto-loading the files above.
307 set dprintf-style gdb|call|agent
309 Control the way in which a dynamic printf is performed; "gdb"
310 requests a GDB printf command, while "call" causes dprintf to call a
311 function in the inferior. "agent" requests that the target agent
312 (such as GDBserver) do the printing.
314 set dprintf-function <expr>
315 show dprintf-function
316 set dprintf-channel <expr>
318 Set the function and optional first argument to the call when using
319 the "call" style of dynamic printf.
321 set disconnected-dprintf on|off
322 show disconnected-dprintf
323 Control whether agent-style dynamic printfs continue to be in effect
324 after GDB disconnects.
326 * New configure options
329 Configure default value for the 'set auto-load scripts-directory'
330 setting above. It defaults to '$debugdir:$datadir/auto-load',
331 $debugdir representing global debugging info directories (available
332 via 'show debug-file-directory') and $datadir representing GDB's data
333 directory (available via 'show data-directory').
335 --with-auto-load-safe-path
336 Configure default value for the 'set auto-load safe-path' setting
337 above. It defaults to the --with-auto-load-dir setting.
339 --without-auto-load-safe-path
340 Set 'set auto-load safe-path' to '/', effectively disabling this
345 z0/z1 conditional breakpoints extension
347 The z0/z1 breakpoint insertion packets have been extended to carry
348 a list of conditional expressions over to the remote stub depending on the
349 condition evaluation mode. The use of this extension can be controlled
350 via the "set remote conditional-breakpoints-packet" command.
354 Specify the signals which the remote stub may pass to the debugged
355 program without GDB involvement.
357 * New command line options
359 --init-command=FILE, -ix Like --command, -x but execute it
360 before loading inferior.
361 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
362 execute it before loading inferior.
364 *** Changes in GDB 7.4
366 * GDB now handles ambiguous linespecs more consistently; the existing
367 FILE:LINE support has been expanded to other types of linespecs. A
368 breakpoint will now be set on all matching locations in all
369 inferiors, and locations will be added or removed according to
372 * GDB now allows you to skip uninteresting functions and files when
373 stepping with the "skip function" and "skip file" commands.
375 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
376 and "show remote hardware-watchpoint-length-limit". These allows to
377 set or show the maximum length limit (in bytes) of a remote
378 target hardware watchpoint.
380 This allows e.g. to use "unlimited" hardware watchpoints with the
381 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
382 watchpoints are slower than real hardware watchpoints but are
383 significantly faster than gdb software watchpoints.
387 ** The register_pretty_printer function in module gdb.printing now takes
388 an optional `replace' argument. If True, the new printer replaces any
391 ** The "maint set python print-stack on|off" command has been
392 deprecated and will be deleted in GDB 7.5.
393 A new command: "set python print-stack none|full|message" has
394 replaced it. Additionally, the default for "print-stack" is
395 now "message", which just prints the error message without
398 ** A prompt substitution hook (prompt_hook) is now available to the
401 ** A new Python module, gdb.prompt has been added to the GDB Python
402 modules library. This module provides functionality for
403 escape sequences in prompts (used by set/show
404 extended-prompt). These escape sequences are replaced by their
407 ** Python commands and convenience-functions located in
408 'data-directory'/python/gdb/command and
409 'data-directory'/python/gdb/function are now automatically loaded
412 ** Blocks now provide four new attributes. global_block and
413 static_block will return the global and static blocks
414 respectively. is_static and is_global are boolean attributes
415 that indicate if the block is one of those two types.
417 ** Symbols now provide the "type" attribute, the type of the symbol.
419 ** The "gdb.breakpoint" function has been deprecated in favor of
422 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
423 of a function. This class is based on the "finish" command
424 available in the CLI.
426 ** Type objects for struct and union types now allow access to
427 the fields using standard Python dictionary (mapping) methods.
428 For example, "some_type['myfield']" now works, as does
431 ** A new event "gdb.new_objfile" has been added, triggered by loading a
434 ** A new function, "deep_items" has been added to the gdb.types
435 module in the GDB Python modules library. This function returns
436 an iterator over the fields of a struct or union type. Unlike
437 the standard Python "iteritems" method, it will recursively traverse
438 any anonymous fields.
442 ** "*stopped" events can report several new "reason"s, such as
445 ** Breakpoint changes are now notified using new async records, like
446 "=breakpoint-modified".
448 ** New command -ada-task-info.
450 * libthread-db-search-path now supports two special values: $sdir and $pdir.
451 $sdir specifies the default system locations of shared libraries.
452 $pdir specifies the directory where the libpthread used by the application
455 GDB no longer looks in $sdir and $pdir after it has searched the directories
456 mentioned in libthread-db-search-path. If you want to search those
457 directories, they must be specified in libthread-db-search-path.
458 The default value of libthread-db-search-path on GNU/Linux and Solaris
459 systems is now "$sdir:$pdir".
461 $pdir is not supported by gdbserver, it is currently ignored.
462 $sdir is supported by gdbserver.
464 * New configure option --with-iconv-bin.
465 When using the internationalization support like the one in the GNU C
466 library, GDB will invoke the "iconv" program to get a list of supported
467 character sets. If this program lives in a non-standard location, one can
468 use this option to specify where to find it.
470 * When natively debugging programs on PowerPC BookE processors running
471 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
472 watchpoints, which specify a mask in addition to an address to watch.
473 The mask specifies that some bits of an address (the bits which are
474 reset in the mask) should be ignored when matching the address accessed
475 by the inferior against the watchpoint address. See the "PowerPC Embedded"
476 section in the user manual for more details.
478 * The new option --once causes GDBserver to stop listening for connections once
479 the first connection is made. The listening port used by GDBserver will
480 become available after that.
482 * New commands "info macros" and "alias" have been added.
484 * New function parameters suffix @entry specifies value of function parameter
485 at the time the function got called. Entry values are available only since
491 "!" is now an alias of the "shell" command.
492 Note that no space is needed between "!" and SHELL COMMAND.
496 watch EXPRESSION mask MASK_VALUE
497 The watch command now supports the mask argument which allows creation
498 of masked watchpoints, if the current architecture supports this feature.
500 info auto-load-scripts [REGEXP]
501 This command was formerly named "maintenance print section-scripts".
502 It is now generally useful and is no longer a maintenance-only command.
504 info macro [-all] [--] MACRO
505 The info macro command has new options `-all' and `--'. The first for
506 printing all definitions of a macro. The second for explicitly specifying
507 the end of arguments and the beginning of the macro name in case the macro
508 name starts with a hyphen.
510 collect[/s] EXPRESSIONS
511 The tracepoint collect command now takes an optional modifier "/s"
512 that directs it to dereference pointer-to-character types and
513 collect the bytes of memory up to a zero byte. The behavior is
514 similar to what you see when you use the regular print command on a
515 string. An optional integer following the "/s" sets a bound on the
516 number of bytes that will be collected.
519 The trace start command now interprets any supplied arguments as a
520 note to be recorded with the trace run, with an effect similar to
521 setting the variable trace-notes.
524 The trace stop command now interprets any arguments as a note to be
525 mentioned along with the tstatus report that the trace was stopped
526 with a command. The effect is similar to setting the variable
529 * Tracepoints can now be enabled and disabled at any time after a trace
530 experiment has been started using the standard "enable" and "disable"
531 commands. It is now possible to start a trace experiment with no enabled
532 tracepoints; GDB will display a warning, but will allow the experiment to
533 begin, assuming that tracepoints will be enabled as needed while the trace
536 * Fast tracepoints on 32-bit x86-architectures can now be placed at
537 locations with 4-byte instructions, when they were previously
538 limited to locations with instructions of 5 bytes or longer.
542 set debug dwarf2-read
543 show debug dwarf2-read
544 Turns on or off display of debugging messages related to reading
545 DWARF debug info. The default is off.
547 set debug symtab-create
548 show debug symtab-create
549 Turns on or off display of debugging messages related to symbol table
550 creation. The default is off.
554 Set the GDB prompt, and allow escape sequences to be inserted to
555 display miscellaneous information (see 'help set extended-prompt'
556 for the list of sequences). This prompt (and any information
557 accessed through the escape sequences) is updated every time the
560 set print entry-values (both|compact|default|if-needed|no|only|preferred)
561 show print entry-values
562 Set printing of frame argument values at function entry. In some cases
563 GDB can determine the value of function argument which was passed by the
564 function caller, even if the value was modified inside the called function.
566 set debug entry-values
567 show debug entry-values
568 Control display of debugging info for determining frame argument values at
569 function entry and virtual tail call frames.
571 set basenames-may-differ
572 show basenames-may-differ
573 Set whether a source file may have multiple base names.
574 (A "base name" is the name of a file with the directory part removed.
575 Example: The base name of "/home/user/hello.c" is "hello.c".)
576 If set, GDB will canonicalize file names (e.g., expand symlinks)
577 before comparing them. Canonicalization is an expensive operation,
578 but it allows the same file be known by more than one base name.
579 If not set (the default), all source files are assumed to have just
580 one base name, and gdb will do file name comparisons more efficiently.
586 Set a user name and notes for the current and any future trace runs.
587 This is useful for long-running and/or disconnected traces, to
588 inform others (or yourself) as to who is running the trace, supply
589 contact information, or otherwise explain what is going on.
592 show trace-stop-notes
593 Set a note attached to the trace run, that is displayed when the
594 trace has been stopped by a tstop command. This is useful for
595 instance as an explanation, if you are stopping a trace run that was
596 started by someone else.
602 Dynamically enable a tracepoint in a started trace experiment.
606 Dynamically disable a tracepoint in a started trace experiment.
610 Set the user and notes of the trace run.
614 Query the current status of a tracepoint.
618 Query the minimum length of instruction at which a fast tracepoint may
621 * Dcache size (number of lines) and line-size are now runtime-configurable
622 via "set dcache line" and "set dcache line-size" commands.
626 Texas Instruments TMS320C6x tic6x-*-*
630 Renesas RL78 rl78-*-elf
632 *** Changes in GDB 7.3.1
634 * The build failure for NetBSD and OpenBSD targets have now been fixed.
636 *** Changes in GDB 7.3
638 * GDB has a new command: "thread find [REGEXP]".
639 It finds the thread id whose name, target id, or thread extra info
640 matches the given regular expression.
642 * The "catch syscall" command now works on mips*-linux* targets.
644 * The -data-disassemble MI command now supports modes 2 and 3 for
645 dumping the instruction opcodes.
647 * New command line options
649 -data-directory DIR Specify DIR as the "data-directory".
650 This is mostly for testing purposes.
652 * The "maint set python auto-load on|off" command has been renamed to
653 "set auto-load-scripts on|off".
655 * GDB has a new command: "set directories".
656 It is like the "dir" command except that it replaces the
657 source path list instead of augmenting it.
659 * GDB now understands thread names.
661 On GNU/Linux, "info threads" will display the thread name as set by
662 prctl or pthread_setname_np.
664 There is also a new command, "thread name", which can be used to
665 assign a name internally for GDB to display.
668 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
669 has been integrated into GDB.
673 ** The function gdb.Write now accepts an optional keyword 'stream'.
674 This keyword, when provided, will direct the output to either
675 stdout, stderr, or GDB's logging output.
677 ** Parameters can now be be sub-classed in Python, and in particular
678 you may implement the get_set_doc and get_show_doc functions.
679 This improves how Parameter set/show documentation is processed
680 and allows for more dynamic content.
682 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
683 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
684 have an is_valid method.
686 ** Breakpoints can now be sub-classed in Python, and in particular
687 you may implement a 'stop' function that is executed each time
688 the inferior reaches that breakpoint.
690 ** New function gdb.lookup_global_symbol looks up a global symbol.
692 ** GDB values in Python are now callable if the value represents a
693 function. For example, if 'some_value' represents a function that
694 takes two integer parameters and returns a value, you can call
695 that function like so:
697 result = some_value (10,20)
699 ** Module gdb.types has been added.
700 It contains a collection of utilities for working with gdb.Types objects:
701 get_basic_type, has_field, make_enum_dict.
703 ** Module gdb.printing has been added.
704 It contains utilities for writing and registering pretty-printers.
705 New classes: PrettyPrinter, SubPrettyPrinter,
706 RegexpCollectionPrettyPrinter.
707 New function: register_pretty_printer.
709 ** New commands "info pretty-printers", "enable pretty-printer" and
710 "disable pretty-printer" have been added.
712 ** gdb.parameter("directories") is now available.
714 ** New function gdb.newest_frame returns the newest frame in the
717 ** The gdb.InferiorThread class has a new "name" attribute. This
718 holds the thread's name.
720 ** Python Support for Inferior events.
721 Python scripts can add observers to be notified of events
722 occurring in the process being debugged.
723 The following events are currently supported:
724 - gdb.events.cont Continue event.
725 - gdb.events.exited Inferior exited event.
726 - gdb.events.stop Signal received, and Breakpoint hit events.
730 ** GDB now puts template parameters in scope when debugging in an
731 instantiation. For example, if you have:
733 template<int X> int func (void) { return X; }
735 then if you step into func<5>, "print X" will show "5". This
736 feature requires proper debuginfo support from the compiler; it
737 was added to GCC 4.5.
739 ** The motion commands "next", "finish", "until", and "advance" now
740 work better when exceptions are thrown. In particular, GDB will
741 no longer lose control of the inferior; instead, the GDB will
742 stop the inferior at the point at which the exception is caught.
743 This functionality requires a change in the exception handling
744 code that was introduced in GCC 4.5.
746 * GDB now follows GCC's rules on accessing volatile objects when
747 reading or writing target state during expression evaluation.
748 One notable difference to prior behavior is that "print x = 0"
749 no longer generates a read of x; the value of the assignment is
750 now always taken directly from the value being assigned.
752 * GDB now has some support for using labels in the program's source in
753 linespecs. For instance, you can use "advance label" to continue
754 execution to a label.
756 * GDB now has support for reading and writing a new .gdb_index
757 section. This section holds a fast index of DWARF debugging
758 information and can be used to greatly speed up GDB startup and
759 operation. See the documentation for `save gdb-index' for details.
761 * The "watch" command now accepts an optional "-location" argument.
762 When used, this causes GDB to watch the memory referred to by the
763 expression. Such a watchpoint is never deleted due to it going out
766 * GDB now supports thread debugging of core dumps on GNU/Linux.
768 GDB now activates thread debugging using the libthread_db library
769 when debugging GNU/Linux core dumps, similarly to when debugging
770 live processes. As a result, when debugging a core dump file, GDB
771 is now able to display pthread_t ids of threads. For example, "info
772 threads" shows the same output as when debugging the process when it
773 was live. In earlier releases, you'd see something like this:
776 * 1 LWP 6780 main () at main.c:10
778 While now you see this:
781 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
783 It is also now possible to inspect TLS variables when debugging core
786 When debugging a core dump generated on a machine other than the one
787 used to run GDB, you may need to point GDB at the correct
788 libthread_db library with the "set libthread-db-search-path"
789 command. See the user manual for more details on this command.
791 * When natively debugging programs on PowerPC BookE processors running
792 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
793 which stop execution of the inferior whenever it executes an instruction
794 at any address within the specified range. See the "PowerPC Embedded"
795 section in the user manual for more details.
797 * New features in the GDB remote stub, GDBserver
799 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
800 and i686 LynxOS (version 5.x).
802 ** GDBserver is now supported on Blackfin Linux.
804 * New native configurations
806 ia64 HP-UX ia64-*-hpux*
810 Analog Devices, Inc. Blackfin Processor bfin-*
812 * Ada task switching is now supported on sparc-elf targets when
813 debugging a program using the Ravenscar Profile. For more information,
814 see the "Tasking Support when using the Ravenscar Profile" section
815 in the GDB user manual.
817 * Guile support was removed.
819 * New features in the GNU simulator
821 ** The --map-info flag lists all known core mappings.
823 ** CFI flashes may be simulated via the "cfi" device.
825 *** Changes in GDB 7.2
827 * Shared library support for remote targets by default
829 When GDB is configured for a generic, non-OS specific target, like
830 for example, --target=arm-eabi or one of the many *-*-elf targets,
831 GDB now queries remote stubs for loaded shared libraries using the
832 `qXfer:libraries:read' packet. Previously, shared library support
833 was always disabled for such configurations.
837 ** Argument Dependent Lookup (ADL)
839 In C++ ADL lookup directs function search to the namespaces of its
840 arguments even if the namespace has not been imported.
850 Here the compiler will search for `foo' in the namespace of 'b'
851 and find A::foo. GDB now supports this. This construct is commonly
852 used in the Standard Template Library for operators.
854 ** Improved User Defined Operator Support
856 In addition to member operators, GDB now supports lookup of operators
857 defined in a namespace and imported with a `using' directive, operators
858 defined in the global scope, operators imported implicitly from an
859 anonymous namespace, and the ADL operators mentioned in the previous
861 GDB now also supports proper overload resolution for all the previously
862 mentioned flavors of operators.
864 ** static const class members
866 Printing of static const class members that are initialized in the
867 class definition has been fixed.
869 * Windows Thread Information Block access.
871 On Windows targets, GDB now supports displaying the Windows Thread
872 Information Block (TIB) structure. This structure is visible either
873 by using the new command `info w32 thread-information-block' or, by
874 dereferencing the new convenience variable named `$_tlb', a
875 thread-specific pointer to the TIB. This feature is also supported
876 when remote debugging using GDBserver.
880 Static tracepoints are calls in the user program into a tracing
881 library. One such library is a port of the LTTng kernel tracer to
882 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
883 When debugging with GDBserver, GDB now supports combining the GDB
884 tracepoint machinery with such libraries. For example: the user can
885 use GDB to probe a static tracepoint marker (a call from the user
886 program into the tracing library) with the new "strace" command (see
887 "New commands" below). This creates a "static tracepoint" in the
888 breakpoint list, that can be manipulated with the same feature set
889 as fast and regular tracepoints. E.g., collect registers, local and
890 global variables, collect trace state variables, and define
891 tracepoint conditions. In addition, the user can collect extra
892 static tracepoint marker specific data, by collecting the new
893 $_sdata internal variable. When analyzing the trace buffer, you can
894 inspect $_sdata like any other variable available to GDB. For more
895 information, see the "Tracepoints" chapter in GDB user manual. New
896 remote packets have been defined to support static tracepoints, see
897 the "New remote packets" section below.
899 * Better reconstruction of tracepoints after disconnected tracing
901 GDB will attempt to download the original source form of tracepoint
902 definitions when starting a trace run, and then will upload these
903 upon reconnection to the target, resulting in a more accurate
904 reconstruction of the tracepoints that are in use on the target.
908 You can now exercise direct control over the ways that GDB can
909 affect your program. For instance, you can disallow the setting of
910 breakpoints, so that the program can run continuously (assuming
911 non-stop mode). In addition, the "observer" variable is available
912 to switch all of the different controls; in observer mode, GDB
913 cannot affect the target's behavior at all, which is useful for
914 tasks like diagnosing live systems in the field.
916 * The new convenience variable $_thread holds the number of the
923 Return the address of the Windows Thread Information Block of a given thread.
927 In response to several of the tracepoint packets, the target may now
928 also respond with a number of intermediate `qRelocInsn' request
929 packets before the final result packet, to have GDB handle
930 relocating an instruction to execute at a different address. This
931 is particularly useful for stubs that support fast tracepoints. GDB
932 reports support for this feature in the qSupported packet.
936 List static tracepoint markers in the target program.
940 List static tracepoint markers at a given address in the target
943 qXfer:statictrace:read
945 Read the static trace data collected (by a `collect $_sdata'
946 tracepoint action). The remote stub reports support for this packet
947 to gdb's qSupported query.
951 Send the current settings of GDB's permission flags.
955 Send part of the source (textual) form of a tracepoint definition,
956 which includes location, conditional, and action list.
958 * The source command now accepts a -s option to force searching for the
959 script in the source search path even if the script name specifies
962 * New features in the GDB remote stub, GDBserver
964 - GDBserver now support tracepoints (including fast tracepoints, and
965 static tracepoints). The feature is currently supported by the
966 i386-linux and amd64-linux builds. See the "Tracepoints support
967 in gdbserver" section in the manual for more information.
969 GDBserver JIT compiles the tracepoint's conditional agent
970 expression bytecode into native code whenever possible for low
971 overhead dynamic tracepoints conditionals. For such tracepoints,
972 an expression that examines program state is evaluated when the
973 tracepoint is reached, in order to determine whether to capture
974 trace data. If the condition is simple and false, processing the
975 tracepoint finishes very quickly and no data is gathered.
977 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
978 for static tracepoints support.
980 - GDBserver now supports x86_64 Windows 64-bit debugging.
982 * GDB now sends xmlRegisters= in qSupported packet to indicate that
983 it understands register description.
985 * The --batch flag now disables pagination and queries.
987 * X86 general purpose registers
989 GDB now supports reading/writing byte, word and double-word x86
990 general purpose registers directly. This means you can use, say,
991 $ah or $ax to refer, respectively, to the byte register AH and
992 16-bit word register AX that are actually portions of the 32-bit
993 register EAX or 64-bit register RAX.
995 * The `commands' command now accepts a range of breakpoints to modify.
996 A plain `commands' following a command that creates multiple
997 breakpoints affects all the breakpoints set by that command. This
998 applies to breakpoints set by `rbreak', and also applies when a
999 single `break' command creates multiple breakpoints (e.g.,
1000 breakpoints on overloaded c++ functions).
1002 * The `rbreak' command now accepts a filename specification as part of
1003 its argument, limiting the functions selected by the regex to those
1004 in the specified file.
1006 * Support for remote debugging Windows and SymbianOS shared libraries
1007 from Unix hosts has been improved. Non Windows GDB builds now can
1008 understand target reported file names that follow MS-DOS based file
1009 system semantics, such as file names that include drive letters and
1010 use the backslash character as directory separator. This makes it
1011 possible to transparently use the "set sysroot" and "set
1012 solib-search-path" on Unix hosts to point as host copies of the
1013 target's shared libraries. See the new command "set
1014 target-file-system-kind" described below, and the "Commands to
1015 specify files" section in the user manual for more information.
1019 eval template, expressions...
1020 Convert the values of one or more expressions under the control
1021 of the string template to a command line, and call it.
1023 set target-file-system-kind unix|dos-based|auto
1024 show target-file-system-kind
1025 Set or show the assumed file system kind for target reported file
1028 save breakpoints <filename>
1029 Save all current breakpoint definitions to a file suitable for use
1030 in a later debugging session. To read the saved breakpoint
1031 definitions, use the `source' command.
1033 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1036 info static-tracepoint-markers
1037 Display information about static tracepoint markers in the target.
1039 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1040 Define a static tracepoint by probing a marker at the given
1041 function, line, address, or marker ID.
1045 Enable and disable observer mode.
1047 set may-write-registers on|off
1048 set may-write-memory on|off
1049 set may-insert-breakpoints on|off
1050 set may-insert-tracepoints on|off
1051 set may-insert-fast-tracepoints on|off
1052 set may-interrupt on|off
1053 Set individual permissions for GDB effects on the target. Note that
1054 some of these settings can have undesirable or surprising
1055 consequences, particularly when changed in the middle of a session.
1056 For instance, disabling the writing of memory can prevent
1057 breakpoints from being inserted, cause single-stepping to fail, or
1058 even crash your program, if you disable after breakpoints have been
1059 inserted. However, GDB should not crash.
1061 set record memory-query on|off
1062 show record memory-query
1063 Control whether to stop the inferior if memory changes caused
1064 by an instruction cannot be recorded.
1069 The disassemble command now supports "start,+length" form of two arguments.
1073 ** GDB now provides a new directory location, called the python directory,
1074 where Python scripts written for GDB can be installed. The location
1075 of that directory is <data-directory>/python, where <data-directory>
1076 is the GDB data directory. For more details, see section `Scripting
1077 GDB using Python' in the manual.
1079 ** The GDB Python API now has access to breakpoints, symbols, symbol
1080 tables, program spaces, inferiors, threads and frame's code blocks.
1081 Additionally, GDB Parameters can now be created from the API, and
1082 manipulated via set/show in the CLI.
1084 ** New functions gdb.target_charset, gdb.target_wide_charset,
1085 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1087 ** New exception gdb.GdbError.
1089 ** Pretty-printers are now also looked up in the current program space.
1091 ** Pretty-printers can now be individually enabled and disabled.
1093 ** GDB now looks for names of Python scripts to auto-load in a
1094 special section named `.debug_gdb_scripts', in addition to looking
1095 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1097 * Tracepoint actions were unified with breakpoint commands. In particular,
1098 there are no longer differences in "info break" output for breakpoints and
1099 tracepoints and the "commands" command can be used for both tracepoints and
1100 regular breakpoints.
1104 ARM Symbian arm*-*-symbianelf*
1106 * D language support.
1107 GDB now supports debugging programs written in the D programming
1110 * GDB now supports the extended ptrace interface for PowerPC which is
1111 available since Linux kernel version 2.6.34. This automatically enables
1112 any hardware breakpoints and additional hardware watchpoints available in
1113 the processor. The old ptrace interface exposes just one hardware
1114 watchpoint and no hardware breakpoints.
1116 * GDB is now able to use the Data Value Compare (DVC) register available on
1117 embedded PowerPC processors to implement in hardware simple watchpoint
1118 conditions of the form:
1120 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1122 This works in native GDB running on Linux kernels with the extended ptrace
1123 interface mentioned above.
1125 *** Changes in GDB 7.1
1129 ** Namespace Support
1131 GDB now supports importing of namespaces in C++. This enables the
1132 user to inspect variables from imported namespaces. Support for
1133 namepace aliasing has also been added. So, if a namespace is
1134 aliased in the current scope (e.g. namepace C=A; ) the user can
1135 print variables using the alias (e.g. (gdb) print C::x).
1139 All known bugs relating to the printing of virtual base class were
1140 fixed. It is now possible to call overloaded static methods using a
1145 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1146 and reinterpret_cast<> are now handled by the C++ expression parser.
1150 Xilinx MicroBlaze microblaze-*-*
1155 Xilinx MicroBlaze microblaze
1158 * Multi-program debugging.
1160 GDB now has support for multi-program (a.k.a. multi-executable or
1161 multi-exec) debugging. This allows for debugging multiple inferiors
1162 simultaneously each running a different program under the same GDB
1163 session. See "Debugging Multiple Inferiors and Programs" in the
1164 manual for more information. This implied some user visible changes
1165 in the multi-inferior support. For example, "info inferiors" now
1166 lists inferiors that are not running yet or that have exited
1167 already. See also "New commands" and "New options" below.
1169 * New tracing features
1171 GDB's tracepoint facility now includes several new features:
1173 ** Trace state variables
1175 GDB tracepoints now include support for trace state variables, which
1176 are variables managed by the target agent during a tracing
1177 experiment. They are useful for tracepoints that trigger each
1178 other, so for instance one tracepoint can count hits in a variable,
1179 and then a second tracepoint has a condition that is true when the
1180 count reaches a particular value. Trace state variables share the
1181 $-syntax of GDB convenience variables, and can appear in both
1182 tracepoint actions and condition expressions. Use the "tvariable"
1183 command to create, and "info tvariables" to view; see "Trace State
1184 Variables" in the manual for more detail.
1188 GDB now includes an option for defining fast tracepoints, which
1189 targets may implement more efficiently, such as by installing a jump
1190 into the target agent rather than a trap instruction. The resulting
1191 speedup can be by two orders of magnitude or more, although the
1192 tradeoff is that some program locations on some target architectures
1193 might not allow fast tracepoint installation, for instance if the
1194 instruction to be replaced is shorter than the jump. To request a
1195 fast tracepoint, use the "ftrace" command, with syntax identical to
1196 the regular trace command.
1198 ** Disconnected tracing
1200 It is now possible to detach GDB from the target while it is running
1201 a trace experiment, then reconnect later to see how the experiment
1202 is going. In addition, a new variable disconnected-tracing lets you
1203 tell the target agent whether to continue running a trace if the
1204 connection is lost unexpectedly.
1208 GDB now has the ability to save the trace buffer into a file, and
1209 then use that file as a target, similarly to you can do with
1210 corefiles. You can select trace frames, print data that was
1211 collected in them, and use tstatus to display the state of the
1212 tracing run at the moment that it was saved. To create a trace
1213 file, use "tsave <filename>", and to use it, do "target tfile
1216 ** Circular trace buffer
1218 You can ask the target agent to handle the trace buffer as a
1219 circular buffer, discarding the oldest trace frames to make room for
1220 newer ones, by setting circular-trace-buffer to on. This feature may
1221 not be available for all target agents.
1226 The disassemble command, when invoked with two arguments, now requires
1227 the arguments to be comma-separated.
1230 The info variables command now displays variable definitions. Files
1231 which only declare a variable are not shown.
1234 The source command is now capable of sourcing Python scripts.
1235 This feature is dependent on the debugger being build with Python
1238 Related to this enhancement is also the introduction of a new command
1239 "set script-extension" (see below).
1241 * New commands (for set/show, see "New options" below)
1243 record save [<FILENAME>]
1244 Save a file (in core file format) containing the process record
1245 execution log for replay debugging at a later time.
1247 record restore <FILENAME>
1248 Restore the process record execution log that was saved at an
1249 earlier time, for replay debugging.
1251 add-inferior [-copies <N>] [-exec <FILENAME>]
1254 clone-inferior [-copies <N>] [ID]
1255 Make a new inferior ready to execute the same program another
1256 inferior has loaded.
1261 maint info program-spaces
1262 List the program spaces loaded into GDB.
1264 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1265 show remote interrupt-sequence
1266 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1267 as the sequence to the remote target in order to interrupt the execution.
1268 Ctrl-C is a default. Some system prefers BREAK which is high level of
1269 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1270 Magic SysRq g. It is BREAK signal and character 'g'.
1272 set remote interrupt-on-connect [on | off]
1273 show remote interrupt-on-connect
1274 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1275 remote target when gdb connects to it. This is needed when you debug
1278 set remotebreak [on | off]
1280 Deprecated. Use "set/show remote interrupt-sequence" instead.
1282 tvariable $NAME [ = EXP ]
1283 Create or modify a trace state variable.
1286 List trace state variables and their values.
1288 delete tvariable $NAME ...
1289 Delete one or more trace state variables.
1292 Evaluate the given expressions without collecting anything into the
1293 trace buffer. (Valid in tracepoint actions only.)
1295 ftrace FN / FILE:LINE / *ADDR
1296 Define a fast tracepoint at the given function, line, or address.
1298 * New expression syntax
1300 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1301 GDB now parses 0b101010 identically with 42.
1305 set follow-exec-mode new|same
1306 show follow-exec-mode
1307 Control whether GDB reuses the same inferior across an exec call or
1308 creates a new one. This is useful to be able to restart the old
1309 executable after the inferior having done an exec call.
1311 set default-collect EXPR, ...
1312 show default-collect
1313 Define a list of expressions to be collected at each tracepoint.
1314 This is a useful way to ensure essential items are not overlooked,
1315 such as registers or a critical global variable.
1317 set disconnected-tracing
1318 show disconnected-tracing
1319 If set to 1, the target is instructed to continue tracing if it
1320 loses its connection to GDB. If 0, the target is to stop tracing
1323 set circular-trace-buffer
1324 show circular-trace-buffer
1325 If set to on, the target is instructed to use a circular trace buffer
1326 and discard the oldest trace frames instead of stopping the trace due
1327 to a full trace buffer. If set to off, the trace stops when the buffer
1328 fills up. Some targets may not support this.
1330 set script-extension off|soft|strict
1331 show script-extension
1332 If set to "off", the debugger does not perform any script language
1333 recognition, and all sourced files are assumed to be GDB scripts.
1334 If set to "soft" (the default), files are sourced according to
1335 filename extension, falling back to GDB scripts if the first
1337 If set to "strict", files are sourced according to filename extension.
1339 set ada trust-PAD-over-XVS on|off
1340 show ada trust-PAD-over-XVS
1341 If off, activate a workaround against a bug in the debugging information
1342 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1343 the GCC sources for more information about the GNAT encoding and
1344 PAD types in particular). It is always safe to set this option to
1345 off, but this introduces a slight performance penalty. The default
1348 * Python API Improvements
1350 ** GDB provides the new class gdb.LazyString. This is useful in
1351 some pretty-printing cases. The new method gdb.Value.lazy_string
1352 provides a simple way to create objects of this type.
1354 ** The fields returned by gdb.Type.fields now have an
1355 `is_base_class' attribute.
1357 ** The new method gdb.Type.range returns the range of an array type.
1359 ** The new method gdb.parse_and_eval can be used to parse and
1360 evaluate an expression.
1362 * New remote packets
1365 Define a trace state variable.
1368 Get the current value of a trace state variable.
1371 Set desired tracing behavior upon disconnection.
1374 Set the trace buffer to be linear or circular.
1377 Get data about the tracepoints currently in use.
1381 Process record now works correctly with hardware watchpoints.
1383 Multiple bug fixes have been made to the mips-irix port, making it
1384 much more reliable. In particular:
1385 - Debugging threaded applications is now possible again. Previously,
1386 GDB would hang while starting the program, or while waiting for
1387 the program to stop at a breakpoint.
1388 - Attaching to a running process no longer hangs.
1389 - An error occurring while loading a core file has been fixed.
1390 - Changing the value of the PC register now works again. This fixes
1391 problems observed when using the "jump" command, or when calling
1392 a function from GDB, or even when assigning a new value to $pc.
1393 - With the "finish" and "return" commands, the return value for functions
1394 returning a small array is now correctly printed.
1395 - It is now possible to break on shared library code which gets executed
1396 during a shared library init phase (code executed while executing
1397 their .init section). Previously, the breakpoint would have no effect.
1398 - GDB is now able to backtrace through the signal handler for
1399 non-threaded programs.
1401 PIE (Position Independent Executable) programs debugging is now supported.
1402 This includes debugging execution of PIC (Position Independent Code) shared
1403 libraries although for that, it should be possible to run such libraries as an
1406 *** Changes in GDB 7.0
1408 * GDB now has an interface for JIT compilation. Applications that
1409 dynamically generate code can create symbol files in memory and register
1410 them with GDB. For users, the feature should work transparently, and
1411 for JIT developers, the interface is documented in the GDB manual in the
1412 "JIT Compilation Interface" chapter.
1414 * Tracepoints may now be conditional. The syntax is as for
1415 breakpoints; either an "if" clause appended to the "trace" command,
1416 or the "condition" command is available. GDB sends the condition to
1417 the target for evaluation using the same bytecode format as is used
1418 for tracepoint actions.
1420 * The disassemble command now supports: an optional /r modifier, print the
1421 raw instructions in hex as well as in symbolic form, and an optional /m
1422 modifier to print mixed source+assembly.
1424 * Process record and replay
1426 In a architecture environment that supports ``process record and
1427 replay'', ``process record and replay'' target can record a log of
1428 the process execution, and replay it with both forward and reverse
1431 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1432 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1433 set execution-direction {forward|reverse}, for targets that support
1436 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1437 feature is available with a native GDB running on kernel version
1440 * GDB now has support for multi-byte and wide character sets on the
1441 target. Strings whose character type is wchar_t, char16_t, or
1442 char32_t are now correctly printed. GDB supports wide- and unicode-
1443 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1444 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1445 `printf'. This feature requires iconv to work properly; if your
1446 system does not have a working iconv, GDB can use GNU libiconv. See
1447 the installation instructions for more information.
1449 * GDB now supports automatic retrieval of shared library files from
1450 remote targets. To use this feature, specify a system root that begins
1451 with the `remote:' prefix, either via the `set sysroot' command or via
1452 the `--with-sysroot' configure-time option.
1454 * "info sharedlibrary" now takes an optional regex of libraries to show,
1455 and it now reports if a shared library has no debugging information.
1457 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1458 now complete on file names.
1460 * When completing in expressions, gdb will attempt to limit
1461 completions to allowable structure or union fields, where appropriate.
1462 For instance, consider:
1464 # struct example { int f1; double f2; };
1465 # struct example variable;
1468 If the user types TAB at the end of this command line, the available
1469 completions will be "f1" and "f2".
1471 * Inlined functions are now supported. They show up in backtraces, and
1472 the "step", "next", and "finish" commands handle them automatically.
1474 * GDB now supports the token-splicing (##) and stringification (#)
1475 operators when expanding macros. It also supports variable-arity
1478 * GDB now supports inspecting extra signal information, exported by
1479 the new $_siginfo convenience variable. The feature is currently
1480 implemented on linux ARM, i386 and amd64.
1482 * GDB can now display the VFP floating point registers and NEON vector
1483 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1484 can provide these registers (requires Linux 2.6.30 or later). Remote
1485 and simulator targets may also provide them.
1487 * New remote packets
1490 Search memory for a sequence of bytes.
1493 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1494 operation over reliable transport links. Use of this packet is
1495 controlled by the `set remote noack-packet' command.
1498 Kill the process with the specified process ID. Use this in preference
1499 to `k' when multiprocess protocol extensions are supported.
1502 Obtains additional operating system information
1506 Read or write additional signal information.
1508 * Removed remote protocol undocumented extension
1510 An undocumented extension to the remote protocol's `S' stop reply
1511 packet that permited the stub to pass a process id was removed.
1512 Remote servers should use the `T' stop reply packet instead.
1514 * GDB now supports multiple function calling conventions according to the
1515 DWARF-2 DW_AT_calling_convention function attribute.
1517 * The SH target utilizes the aforementioned change to distinguish between gcc
1518 and Renesas calling convention. It also adds the new CLI commands
1519 `set/show sh calling-convention'.
1521 * GDB can now read compressed debug sections, as produced by GNU gold
1522 with the --compress-debug-sections=zlib flag.
1524 * 64-bit core files are now supported on AIX.
1526 * Thread switching is now supported on Tru64.
1528 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1529 which will be allocated using malloc later in program execution.
1531 * The qXfer:libraries:read remote procotol packet now allows passing a
1532 list of section offsets.
1534 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1535 conditions handling signals delivered during attach or thread creation
1536 have also been fixed.
1538 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1539 From the user's standpoint, all unqualified instances of True and False
1540 are treated as the standard definitions, regardless of context.
1542 * GDB now parses C++ symbol and type names more flexibly. For
1545 template<typename T> class C { };
1548 GDB will now correctly handle all of:
1550 ptype C<char const *>
1551 ptype C<char const*>
1552 ptype C<const char *>
1553 ptype C<const char*>
1555 * New features in the GDB remote stub, gdbserver
1557 - The "--wrapper" command-line argument tells gdbserver to use a
1558 wrapper program to launch programs for debugging.
1560 - On PowerPC and S/390 targets, it is now possible to use a single
1561 gdbserver executable to debug both 32-bit and 64-bit programs.
1562 (This requires gdbserver itself to be built as a 64-bit executable.)
1564 - gdbserver uses the new noack protocol mode for TCP connections to
1565 reduce communications latency, if also supported and enabled in GDB.
1567 - Support for the sparc64-linux-gnu target is now included in
1570 - The amd64-linux build of gdbserver now supports debugging both
1571 32-bit and 64-bit programs.
1573 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1574 now support hardware watchpoints, and will use them automatically
1579 GDB now has support for scripting using Python. Whether this is
1580 available is determined at configure time.
1582 New GDB commands can now be written in Python.
1584 * Ada tasking support
1586 Ada tasks can now be inspected in GDB. The following commands have
1590 Print the list of Ada tasks.
1592 Print detailed information about task number N.
1594 Print the task number of the current task.
1596 Switch the context of debugging to task number N.
1598 * Support for user-defined prefixed commands. The "define" command can
1599 add new commands to existing prefixes, e.g. "target".
1601 * Multi-inferior, multi-process debugging.
1603 GDB now has generalized support for multi-inferior debugging. See
1604 "Debugging Multiple Inferiors" in the manual for more information.
1605 Although availability still depends on target support, the command
1606 set is more uniform now. The GNU/Linux specific multi-forks support
1607 has been migrated to this new framework. This implied some user
1608 visible changes; see "New commands" and also "Removed commands"
1611 * Target descriptions can now describe the target OS ABI. See the
1612 "Target Description Format" section in the user manual for more
1615 * Target descriptions can now describe "compatible" architectures
1616 to indicate that the target can execute applications for a different
1617 architecture in addition to those for the main target architecture.
1618 See the "Target Description Format" section in the user manual for
1621 * Multi-architecture debugging.
1623 GDB now includes general supports for debugging applications on
1624 hybrid systems that use more than one single processor architecture
1625 at the same time. Each such hybrid architecture still requires
1626 specific support to be added. The only hybrid architecture supported
1627 in this version of GDB is the Cell Broadband Engine.
1629 * GDB now supports integrated debugging of Cell/B.E. applications that
1630 use both the PPU and SPU architectures. To enable support for hybrid
1631 Cell/B.E. debugging, you need to configure GDB to support both the
1632 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1633 --enable-targets configure option.
1635 * Non-stop mode debugging.
1637 For some targets, GDB now supports an optional mode of operation in
1638 which you can examine stopped threads while other threads continue
1639 to execute freely. This is referred to as non-stop mode, with the
1640 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1641 section in the user manual for more information.
1643 To be able to support remote non-stop debugging, a remote stub needs
1644 to implement the non-stop mode remote protocol extensions, as
1645 described in the "Remote Non-Stop" section of the user manual. The
1646 GDB remote stub, gdbserver, has been adjusted to support these
1647 extensions on linux targets.
1649 * New commands (for set/show, see "New options" below)
1651 catch syscall [NAME(S) | NUMBER(S)]
1652 Catch system calls. Arguments, which should be names of system
1653 calls or their numbers, mean catch only those syscalls. Without
1654 arguments, every syscall will be caught. When the inferior issues
1655 any of the specified syscalls, GDB will stop and announce the system
1656 call, both when it is called and when its call returns. This
1657 feature is currently available with a native GDB running on the
1658 Linux Kernel, under the following architectures: x86, x86_64,
1659 PowerPC and PowerPC64.
1661 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1663 Search memory for a sequence of bytes.
1665 maint set python print-stack
1666 maint show python print-stack
1667 Show a stack trace when an error is encountered in a Python script.
1670 Invoke CODE by passing it to the Python interpreter.
1675 These allow macros to be defined, undefined, and listed
1679 Show operating system information about processes.
1682 List the inferiors currently under GDB's control.
1685 Switch focus to inferior number NUM.
1688 Detach from inferior number NUM.
1691 Kill inferior number NUM.
1695 set spu stop-on-load
1696 show spu stop-on-load
1697 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1699 set spu auto-flush-cache
1700 show spu auto-flush-cache
1701 Control whether to automatically flush the software-managed cache
1702 during Cell/B.E. debugging.
1704 set sh calling-convention
1705 show sh calling-convention
1706 Control the calling convention used when calling SH target functions.
1709 show debug timestamp
1710 Control display of timestamps with GDB debugging output.
1712 set disassemble-next-line
1713 show disassemble-next-line
1714 Control display of disassembled source lines or instructions when
1717 set remote noack-packet
1718 show remote noack-packet
1719 Set/show the use of remote protocol QStartNoAckMode packet. See above
1720 under "New remote packets."
1722 set remote query-attached-packet
1723 show remote query-attached-packet
1724 Control use of remote protocol `qAttached' (query-attached) packet.
1726 set remote read-siginfo-object
1727 show remote read-siginfo-object
1728 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1731 set remote write-siginfo-object
1732 show remote write-siginfo-object
1733 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1736 set remote reverse-continue
1737 show remote reverse-continue
1738 Control use of remote protocol 'bc' (reverse-continue) packet.
1740 set remote reverse-step
1741 show remote reverse-step
1742 Control use of remote protocol 'bs' (reverse-step) packet.
1744 set displaced-stepping
1745 show displaced-stepping
1746 Control displaced stepping mode. Displaced stepping is a way to
1747 single-step over breakpoints without removing them from the debuggee.
1748 Also known as "out-of-line single-stepping".
1751 show debug displaced
1752 Control display of debugging info for displaced stepping.
1754 maint set internal-error
1755 maint show internal-error
1756 Control what GDB does when an internal error is detected.
1758 maint set internal-warning
1759 maint show internal-warning
1760 Control what GDB does when an internal warning is detected.
1765 Use a wrapper program to launch programs for debugging.
1767 set multiple-symbols (all|ask|cancel)
1768 show multiple-symbols
1769 The value of this variable can be changed to adjust the debugger behavior
1770 when an expression or a breakpoint location contains an ambiguous symbol
1771 name (an overloaded function name, for instance).
1773 set breakpoint always-inserted
1774 show breakpoint always-inserted
1775 Keep breakpoints always inserted in the target, as opposed to inserting
1776 them when resuming the target, and removing them when the target stops.
1777 This option can improve debugger performance on slow remote targets.
1779 set arm fallback-mode (arm|thumb|auto)
1780 show arm fallback-mode
1781 set arm force-mode (arm|thumb|auto)
1783 These commands control how ARM GDB determines whether instructions
1784 are ARM or Thumb. The default for both settings is auto, which uses
1785 the current CPSR value for instructions without symbols; previous
1786 versions of GDB behaved as if "set arm fallback-mode arm".
1788 set disable-randomization
1789 show disable-randomization
1790 Standalone programs run with the virtual address space randomization enabled
1791 by default on some platforms. This option keeps the addresses stable across
1792 multiple debugging sessions.
1796 Control whether other threads are stopped or not when some thread hits
1801 Requests that asynchronous execution is enabled in the target, if available.
1802 In this case, it's possible to resume target in the background, and interact
1803 with GDB while the target is running. "show target-async" displays the
1804 current state of asynchronous execution of the target.
1806 set target-wide-charset
1807 show target-wide-charset
1808 The target-wide-charset is the name of the character set that GDB
1809 uses when printing characters whose type is wchar_t.
1811 set tcp auto-retry (on|off)
1813 set tcp connect-timeout
1814 show tcp connect-timeout
1815 These commands allow GDB to retry failed TCP connections to a remote stub
1816 with a specified timeout period; this is useful if the stub is launched
1817 in parallel with GDB but may not be ready to accept connections immediately.
1819 set libthread-db-search-path
1820 show libthread-db-search-path
1821 Control list of directories which GDB will search for appropriate
1824 set schedule-multiple (on|off)
1825 show schedule-multiple
1826 Allow GDB to resume all threads of all processes or only threads of
1827 the current process.
1831 Use more aggressive caching for accesses to the stack. This improves
1832 performance of remote debugging (particularly backtraces) without
1833 affecting correctness.
1835 set interactive-mode (on|off|auto)
1836 show interactive-mode
1837 Control whether GDB runs in interactive mode (on) or not (off).
1838 When in interactive mode, GDB waits for the user to answer all
1839 queries. Otherwise, GDB does not wait and assumes the default
1840 answer. When set to auto (the default), GDB determines which
1841 mode to use based on the stdin settings.
1846 For program forks, this is replaced by the new more generic `info
1847 inferiors' command. To list checkpoints, you can still use the
1848 `info checkpoints' command, which was an alias for the `info forks'
1852 Replaced by the new `inferior' command. To switch between
1853 checkpoints, you can still use the `restart' command, which was an
1854 alias for the `fork' command.
1857 This is removed, since some targets don't have a notion of
1858 processes. To switch between processes, you can still use the
1859 `inferior' command using GDB's own inferior number.
1862 For program forks, this is replaced by the new more generic `kill
1863 inferior' command. To delete a checkpoint, you can still use the
1864 `delete checkpoint' command, which was an alias for the `delete
1868 For program forks, this is replaced by the new more generic `detach
1869 inferior' command. To detach a checkpoint, you can still use the
1870 `detach checkpoint' command, which was an alias for the `detach
1873 * New native configurations
1875 x86/x86_64 Darwin i[34567]86-*-darwin*
1877 x86_64 MinGW x86_64-*-mingw*
1881 Lattice Mico32 lm32-*
1882 x86 DICOS i[34567]86-*-dicos*
1883 x86_64 DICOS x86_64-*-dicos*
1886 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1887 (mingw32ce) debugging.
1893 These commands were actually not implemented on any target.
1895 *** Changes in GDB 6.8
1897 * New native configurations
1899 NetBSD/hppa hppa*-*netbsd*
1900 Xtensa GNU/Linux xtensa*-*-linux*
1904 NetBSD/hppa hppa*-*-netbsd*
1905 Xtensa GNU/Lunux xtensa*-*-linux*
1907 * Change in command line behavior -- corefiles vs. process ids.
1909 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1910 attaching to process NUMBER fails, GDB no longer attempts to open a
1911 core file named NUMBER. Attaching to a program using the -c option
1912 is no longer supported. Instead, use the '-p' or '--pid' options.
1914 * GDB can now be built as a native debugger for debugging Windows x86
1915 (mingw32) Portable Executable (PE) programs.
1917 * Pending breakpoints no longer change their number when their address
1920 * GDB now supports breakpoints with multiple locations,
1921 including breakpoints on C++ constructors, inside C++ templates,
1922 and in inlined functions.
1924 * GDB's ability to debug optimized code has been improved. GDB more
1925 accurately identifies function bodies and lexical blocks that occupy
1926 more than one contiguous range of addresses.
1928 * Target descriptions can now describe registers for PowerPC.
1930 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1931 registers on PowerPC targets.
1933 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1934 targets even when the libthread_db library is not available.
1936 * The GDB remote stub, gdbserver, now supports the new file transfer
1937 commands (remote put, remote get, and remote delete).
1939 * The GDB remote stub, gdbserver, now supports run and attach in
1940 extended-remote mode.
1942 * hppa*64*-*-hpux11* target broken
1943 The debugger is unable to start a program and fails with the following
1944 error: "Error trying to get information about dynamic linker".
1945 The gdb-6.7 release is also affected.
1947 * GDB now supports the --enable-targets= configure option to allow
1948 building a single GDB executable that supports multiple remote
1949 target architectures.
1951 * GDB now supports debugging C and C++ programs which use the
1952 Decimal Floating Point extension. In addition, the PowerPC target
1953 now has a set of pseudo-registers to inspect decimal float values
1954 stored in two consecutive float registers.
1956 * The -break-insert MI command can optionally create pending
1959 * Improved support for debugging Ada
1960 Many improvements to the Ada language support have been made. These
1962 - Better support for Ada2005 interface types
1963 - Improved handling of arrays and slices in general
1964 - Better support for Taft-amendment types
1965 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1967 - Improved command completion in Ada
1970 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1975 set print frame-arguments (all|scalars|none)
1976 show print frame-arguments
1977 The value of this variable can be changed to control which argument
1978 values should be printed by the debugger when displaying a frame.
1983 Transfer files to and from a remote target, and delete remote files.
1990 Transfer files to and from a remote target, and delete remote files.
1992 * New remote packets
1999 Open, close, read, write, and delete files on the remote system.
2002 Attach to an existing process on the remote system, in extended-remote
2006 Run a new process on the remote system, in extended-remote mode.
2008 *** Changes in GDB 6.7
2010 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2011 bfd, libiberty and opcodes, as revealed by static analysis donated by
2012 Coverity, Inc. (http://scan.coverity.com).
2014 * When looking up multiply-defined global symbols, GDB will now prefer the
2015 symbol definition in the current shared library if it was built using the
2016 -Bsymbolic linker option.
2018 * When the Text User Interface (TUI) is not configured, GDB will now
2019 recognize the -tui command-line option and print a message that the TUI
2022 * The GDB remote stub, gdbserver, now has lower overhead for high
2023 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2025 * GDB for MIPS targets now autodetects whether a remote target provides
2026 32-bit or 64-bit register values.
2028 * Support for C++ member pointers has been improved.
2030 * GDB now understands XML target descriptions, which specify the
2031 target's overall architecture. GDB can read a description from
2032 a local file or over the remote serial protocol.
2034 * Vectors of single-byte data use a new integer type which is not
2035 automatically displayed as character or string data.
2037 * The /s format now works with the print command. It displays
2038 arrays of single-byte integers and pointers to single-byte integers
2041 * Target descriptions can now describe target-specific registers,
2042 for architectures which have implemented the support (currently
2043 only ARM, M68K, and MIPS).
2045 * GDB and the GDB remote stub, gdbserver, now support the XScale
2048 * The GDB remote stub, gdbserver, has been updated to support
2049 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2050 has been rewritten to use the standard GDB remote protocol.
2052 * GDB can now step into C++ functions which are called through thunks.
2054 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2056 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2057 layout. It also supports a TextSeg= and DataSeg= response when only
2058 segment base addresses (rather than offsets) are available.
2060 * The /i format now outputs any trailing branch delay slot instructions
2061 immediately following the last instruction within the count specified.
2063 * The GDB remote protocol "T" stop reply packet now supports a
2064 "library" response. Combined with the new "qXfer:libraries:read"
2065 packet, this response allows GDB to debug shared libraries on targets
2066 where the operating system manages the list of loaded libraries (e.g.
2067 Windows and SymbianOS).
2069 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2070 (DLLs) on Windows and Windows CE targets.
2072 * GDB now supports a faster verification that a .debug file matches its binary
2073 according to its build-id signature, if the signature is present.
2079 Enable or disable hardware flow control (RTS/CTS) on the serial port
2080 when debugging using remote targets.
2082 set mem inaccessible-by-default
2083 show mem inaccessible-by-default
2084 If the target supplies a memory map, for instance via the remote
2085 protocol's "qXfer:memory-map:read" packet, setting this variable
2086 prevents GDB from accessing memory outside the memory map. This
2087 is useful for targets with memory mapped registers or which react
2088 badly to accesses of unmapped address space.
2090 set breakpoint auto-hw
2091 show breakpoint auto-hw
2092 If the target supplies a memory map, for instance via the remote
2093 protocol's "qXfer:memory-map:read" packet, setting this variable
2094 lets GDB use hardware breakpoints automatically for memory regions
2095 where it can not use software breakpoints. This covers both the
2096 "break" command and internal breakpoints used for other commands
2097 including "next" and "finish".
2100 catch exception unhandled
2101 Stop the program execution when Ada exceptions are raised.
2104 Stop the program execution when an Ada assertion failed.
2108 Set an alternate system root for target files. This is a more
2109 general version of "set solib-absolute-prefix", which is now
2110 an alias to "set sysroot".
2113 Provide extended SPU facility status information. This set of
2114 commands is available only when debugging the Cell/B.E. SPU
2117 * New native configurations
2119 OpenBSD/sh sh*-*openbsd*
2122 unset tdesc filename
2124 Use the specified local file as an XML target description, and do
2125 not query the target for its built-in description.
2129 OpenBSD/sh sh*-*-openbsd*
2130 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2131 Toshiba Media Processor mep-elf
2133 * New remote packets
2136 Ignore the specified signals; pass them directly to the debugged program
2137 without stopping other threads or reporting them to GDB.
2139 qXfer:features:read:
2140 Read an XML target description from the target, which describes its
2145 Read or write contents of an spufs file on the target system. These
2146 packets are available only on the Cell/B.E. SPU architecture.
2148 qXfer:libraries:read:
2149 Report the loaded shared libraries. Combined with new "T" packet
2150 response, this packet allows GDB to debug shared libraries on
2151 targets where the operating system manages the list of loaded
2152 libraries (e.g. Windows and SymbianOS).
2156 Support for these obsolete configurations has been removed.
2164 i[34567]86-*-lynxos*
2165 i[34567]86-*-netware*
2166 i[34567]86-*-sco3.2v5*
2167 i[34567]86-*-sco3.2v4*
2169 i[34567]86-*-sysv4.2*
2172 i[34567]86-*-unixware2*
2173 i[34567]86-*-unixware*
2182 * Other removed features
2189 Various m68k-only ROM monitors.
2196 Various Renesas ROM monitors and debugging interfaces for SH and
2201 Support for a Macraigor serial interface to on-chip debugging.
2202 GDB does not directly support the newer parallel or USB
2207 A debug information format. The predecessor to DWARF 2 and
2208 DWARF 3, which are still supported.
2210 Support for the HP aCC compiler on HP-UX/PA-RISC
2212 SOM-encapsulated symbolic debugging information, automatic
2213 invocation of pxdb, and the aCC custom C++ ABI. This does not
2214 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2215 with aCC can still be debugged on an assembly level.
2217 MIPS ".pdr" sections
2219 A MIPS-specific format used to describe stack frame layout
2220 in debugging information.
2224 GDB could work with an older version of Guile to debug
2225 the interpreter and Scheme programs running in it.
2227 set mips stack-arg-size
2228 set mips saved-gpreg-size
2230 Use "set mips abi" to control parameter passing for MIPS.
2232 *** Changes in GDB 6.6
2237 Cell Broadband Engine SPU spu-elf
2239 * GDB can now be configured as a cross-debugger targeting native Windows
2240 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2241 running on a Windows system over TCP/IP to debug Windows programs.
2243 * The GDB remote stub, gdbserver, has been updated to support Windows and
2244 Cygwin debugging. Both single-threaded and multi-threaded programs are
2247 * The "set trust-readonly-sections" command works again. This command was
2248 broken in GDB 6.3, 6.4, and 6.5.
2250 * The "load" command now supports writing to flash memory, if the remote
2251 stub provides the required support.
2253 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2254 longer requires symbolic debug information (e.g. DWARF-2).
2259 unset substitute-path
2260 show substitute-path
2261 Manage a list of substitution rules that GDB uses to rewrite the name
2262 of the directories where the sources are located. This can be useful
2263 for instance when the sources were moved to a different location
2264 between compilation and debugging.
2268 Print each CLI command as it is executed. Each command is prefixed with
2269 a number of `+' symbols representing the nesting depth.
2270 The source command now has a `-v' option to enable the same feature.
2274 The ARM Demon monitor support (RDP protocol, "target rdp").
2276 Kernel Object Display, an embedded debugging feature which only worked with
2277 an obsolete version of Cisco IOS.
2279 The 'set download-write-size' and 'show download-write-size' commands.
2281 * New remote packets
2284 Tell a stub about GDB client features, and request remote target features.
2285 The first feature implemented is PacketSize, which allows the target to
2286 specify the size of packets it can handle - to minimize the number of
2287 packets required and improve performance when connected to a remote
2291 Fetch an OS auxilliary vector from the remote stub. This packet is a
2292 more efficient replacement for qPart:auxv:read.
2294 qXfer:memory-map:read:
2295 Fetch a memory map from the remote stub, including information about
2296 RAM, ROM, and flash memory devices.
2301 Erase and program a flash memory device.
2303 * Removed remote packets
2306 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2307 used it, and only gdbserver implemented it.
2309 *** Changes in GDB 6.5
2313 Renesas M32C/M16C m32c-elf
2315 Morpho Technologies ms1 ms1-elf
2319 init-if-undefined Initialize a convenience variable, but
2320 only if it doesn't already have a value.
2322 The following commands are presently only implemented for native GNU/Linux:
2324 checkpoint Save a snapshot of the program state.
2326 restart <n> Return the program state to a
2327 previously saved state.
2329 info checkpoints List currently saved checkpoints.
2331 delete-checkpoint <n> Delete a previously saved checkpoint.
2333 set|show detach-on-fork Tell gdb whether to detach from a newly
2334 forked process, or to keep debugging it.
2336 info forks List forks of the user program that
2337 are available to be debugged.
2339 fork <n> Switch to debugging one of several
2340 forks of the user program that are
2341 available to be debugged.
2343 delete-fork <n> Delete a fork from the list of forks
2344 that are available to be debugged (and
2345 kill the forked process).
2347 detach-fork <n> Delete a fork from the list of forks
2348 that are available to be debugged (and
2349 allow the process to continue).
2353 Morpho Technologies ms2 ms1-elf
2355 * Improved Windows host support
2357 GDB now builds as a cross debugger hosted on i686-mingw32, including
2358 native console support, and remote communications using either
2359 network sockets or serial ports.
2361 * Improved Modula-2 language support
2363 GDB can now print most types in the Modula-2 syntax. This includes:
2364 basic types, set types, record types, enumerated types, range types,
2365 pointer types and ARRAY types. Procedure var parameters are correctly
2366 printed and hexadecimal addresses and character constants are also
2367 written in the Modula-2 syntax. Best results can be obtained by using
2368 GNU Modula-2 together with the -gdwarf-2 command line option.
2372 The ARM rdi-share module.
2374 The Netware NLM debug server.
2376 *** Changes in GDB 6.4
2378 * New native configurations
2380 OpenBSD/arm arm*-*-openbsd*
2381 OpenBSD/mips64 mips64-*-openbsd*
2385 Morpho Technologies ms1 ms1-elf
2387 * New command line options
2389 --batch-silent As for --batch, but totally silent.
2390 --return-child-result The debugger will exist with the same value
2391 the child (debugged) program exited with.
2392 --eval-command COMMAND, -ex COMMAND
2393 Execute a single GDB CLI command. This may be
2394 specified multiple times and in conjunction
2395 with the --command (-x) option.
2397 * Deprecated commands removed
2399 The following commands, that were deprecated in 2000, have been
2403 set|show arm disassembly-flavor set|show arm disassembler
2404 othernames set arm disassembler
2405 set|show remotedebug set|show debug remote
2406 set|show archdebug set|show debug arch
2407 set|show eventdebug set|show debug event
2410 * New BSD user-level threads support
2412 It is now possible to debug programs using the user-level threads
2413 library on OpenBSD and FreeBSD. Currently supported (target)
2416 FreeBSD/amd64 x86_64-*-freebsd*
2417 FreeBSD/i386 i386-*-freebsd*
2418 OpenBSD/i386 i386-*-openbsd*
2420 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2421 are not yet supported.
2423 * New support for Matsushita MN10300 w/sim added
2424 (Work in progress). mn10300-elf.
2426 * REMOVED configurations and files
2428 VxWorks and the XDR protocol *-*-vxworks
2429 Motorola MCORE mcore-*-*
2430 National Semiconductor NS32000 ns32k-*-*
2432 * New "set print array-indexes" command
2434 After turning this setting "on", GDB prints the index of each element
2435 when displaying arrays. The default is "off" to preserve the previous
2438 * VAX floating point support
2440 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2442 * User-defined command support
2444 In addition to using $arg0..$arg9 for argument passing, it is now possible
2445 to use $argc to determine now many arguments have been passed. See the
2446 section on user-defined commands in the user manual for more information.
2448 *** Changes in GDB 6.3:
2450 * New command line option
2452 GDB now accepts -l followed by a number to set the timeout for remote
2455 * GDB works with GCC -feliminate-dwarf2-dups
2457 GDB now supports a more compact representation of DWARF-2 debug
2458 information using DW_FORM_ref_addr references. These are produced
2459 by GCC with the option -feliminate-dwarf2-dups and also by some
2460 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2461 to use -feliminate-dwarf2-dups.
2463 * Internationalization
2465 When supported by the host system, GDB will be built with
2466 internationalization (libintl). The task of marking up the sources is
2467 continued, we're looking forward to our first translation.
2471 Initial support for debugging programs compiled with the GNAT
2472 implementation of the Ada programming language has been integrated
2473 into GDB. In this release, support is limited to expression evaluation.
2475 * New native configurations
2477 GNU/Linux/m32r m32r-*-linux-gnu
2481 GDB's remote protocol now includes support for the 'p' packet. This
2482 packet is used to fetch individual registers from a remote inferior.
2484 * END-OF-LIFE registers[] compatibility module
2486 GDB's internal register infrastructure has been completely rewritten.
2487 The new infrastructure making possible the implementation of key new
2488 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2491 GDB 6.3 will be the last release to include the the registers[]
2492 compatibility module that allowed out-of-date configurations to
2493 continue to work. This change directly impacts the following
2503 powerpc bdm protocol
2505 Unless there is activity to revive these configurations, they will be
2506 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2508 * OBSOLETE configurations and files
2510 Configurations that have been declared obsolete in this release have
2511 been commented out. Unless there is activity to revive these
2512 configurations, the next release of GDB will have their sources
2513 permanently REMOVED.
2522 *** Changes in GDB 6.2.1:
2524 * MIPS `break main; run' gave an heuristic-fence-post warning
2526 When attempting to run even a simple program, a warning about
2527 heuristic-fence-post being hit would be reported. This problem has
2530 * MIPS IRIX 'long double' crashed GDB
2532 When examining a long double variable, GDB would get a segmentation
2533 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2534 IRIX long double values).
2538 A bug in the VAX stack code was causing problems with the "next"
2539 command. This problem has been fixed.
2541 *** Changes in GDB 6.2:
2543 * Fix for ``many threads''
2545 On GNU/Linux systems that use the NPTL threads library, a program
2546 rapidly creating and deleting threads would confuse GDB leading to the
2549 ptrace: No such process.
2550 thread_db_get_info: cannot get thread info: generic error
2552 This problem has been fixed.
2554 * "-async" and "-noasync" options removed.
2556 Support for the broken "-noasync" option has been removed (it caused
2559 * New ``start'' command.
2561 This command runs the program until the begining of the main procedure.
2563 * New BSD Kernel Data Access Library (libkvm) interface
2565 Using ``target kvm'' it is now possible to debug kernel core dumps and
2566 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2567 platforms. Currently supported (native-only) configurations are:
2569 FreeBSD/amd64 x86_64-*-freebsd*
2570 FreeBSD/i386 i?86-*-freebsd*
2571 NetBSD/i386 i?86-*-netbsd*
2572 NetBSD/m68k m68*-*-netbsd*
2573 NetBSD/sparc sparc-*-netbsd*
2574 OpenBSD/amd64 x86_64-*-openbsd*
2575 OpenBSD/i386 i?86-*-openbsd*
2576 OpenBSD/m68k m68*-openbsd*
2577 OpenBSD/sparc sparc-*-openbsd*
2579 * Signal trampoline code overhauled
2581 Many generic problems with GDB's signal handling code have been fixed.
2582 These include: backtraces through non-contiguous stacks; recognition
2583 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2584 call; backtrace through a signal trampoline; step into and out of
2585 signal handlers; and single-stepping in the signal trampoline.
2587 Please note that kernel bugs are a limiting factor here. These
2588 features have been shown to work on an s390 GNU/Linux system that
2589 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2591 * Cygwin support for DWARF 2 added.
2593 * New native configurations
2595 GNU/Linux/hppa hppa*-*-linux*
2596 OpenBSD/hppa hppa*-*-openbsd*
2597 OpenBSD/m68k m68*-*-openbsd*
2598 OpenBSD/m88k m88*-*-openbsd*
2599 OpenBSD/powerpc powerpc-*-openbsd*
2600 NetBSD/vax vax-*-netbsd*
2601 OpenBSD/vax vax-*-openbsd*
2603 * END-OF-LIFE frame compatibility module
2605 GDB's internal frame infrastructure has been completely rewritten.
2606 The new infrastructure making it possible to support key new features
2607 including DWARF 2 Call Frame Information. To aid in the task of
2608 migrating old configurations to this new infrastructure, a
2609 compatibility module, that allowed old configurations to continue to
2610 work, was also included.
2612 GDB 6.2 will be the last release to include this frame compatibility
2613 module. This change directly impacts the following configurations:
2623 Unless there is activity to revive these configurations, they will be
2624 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2626 * REMOVED configurations and files
2628 Sun 3, running SunOS 3 m68*-*-sunos3*
2629 Sun 3, running SunOS 4 m68*-*-sunos4*
2630 Sun 2, running SunOS 3 m68000-*-sunos3*
2631 Sun 2, running SunOS 4 m68000-*-sunos4*
2632 Motorola 680x0 running LynxOS m68*-*-lynxos*
2633 AT&T 3b1/Unix pc m68*-att-*
2634 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2635 decstation mips-dec-* mips-little-*
2636 riscos mips-*-riscos* mips-*-sysv*
2637 sonymips mips-sony-*
2638 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2640 *** Changes in GDB 6.1.1:
2642 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2644 The TUI (Text-mode User Interface) is now built as part of a default
2645 GDB configuration. It is enabled by either selecting the TUI with the
2646 command line option "-i=tui" or by running the separate "gdbtui"
2647 program. For more information on the TUI, see the manual "Debugging
2650 * Pending breakpoint support (also included in GDB 6.1)
2652 Support has been added to allow you to specify breakpoints in shared
2653 libraries that have not yet been loaded. If a breakpoint location
2654 cannot be found, and the "breakpoint pending" option is set to auto,
2655 GDB queries you if you wish to make the breakpoint pending on a future
2656 shared-library load. If and when GDB resolves the breakpoint symbol,
2657 the pending breakpoint is removed as one or more regular breakpoints
2660 Pending breakpoints are very useful for GCJ Java debugging.
2662 * Fixed ISO-C build problems
2664 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2665 non ISO-C code that stopped them being built using a more strict ISO-C
2666 compiler (e.g., IBM's C compiler).
2668 * Fixed build problem on IRIX 5
2670 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2671 wasn't able to compile compile on an IRIX 5 system.
2673 * Added execute permission to gdb/gdbserver/configure
2675 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2676 permission. This bug would cause configure to fail on a number of
2677 systems (Solaris, IRIX). Ref: server/519.
2679 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2681 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2682 has been updated to use constant array sizes.
2684 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2686 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2687 its generated DWARF Call Frame Info. This encoding was causing GDB to
2688 panic, that panic has been fixed. Ref: gdb/1628.
2690 * Fixed a problem when examining parameters in shared library code.
2692 When examining parameters in optimized shared library code generated
2693 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2694 not available''. GDB now correctly displays the variable's value.
2696 *** Changes in GDB 6.1:
2698 * Removed --with-mmalloc
2700 Support for the mmalloc memory manager has been removed, as it
2701 conflicted with the internal gdb byte cache.
2703 * Changes in AMD64 configurations
2705 The AMD64 target now includes the %cs and %ss registers. As a result
2706 the AMD64 remote protocol has changed; this affects the floating-point
2707 and SSE registers. If you rely on those registers for your debugging,
2708 you should upgrade gdbserver on the remote side.
2710 * Revised SPARC target
2712 The SPARC target has been completely revised, incorporating the
2713 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2714 support for LynxOS and SunOS 4 has been dropped. Calling functions
2715 from within GDB on operating systems with a non-executable stack
2716 (Solaris, OpenBSD) now works.
2720 GDB has a new C++ demangler which does a better job on the mangled
2721 names generated by current versions of g++. It also runs faster, so
2722 with this and other changes gdb should now start faster on large C++
2725 * DWARF 2 Location Expressions
2727 GDB support for location expressions has been extended to support function
2728 arguments and frame bases. Older versions of GDB could crash when they
2731 * C++ nested types and namespaces
2733 GDB's support for nested types and namespaces in C++ has been
2734 improved, especially if you use the DWARF 2 debugging format. (This
2735 is the default for recent versions of GCC on most platforms.)
2736 Specifically, if you have a class "Inner" defined within a class or
2737 namespace "Outer", then GDB realizes that the class's name is
2738 "Outer::Inner", not simply "Inner". This should greatly reduce the
2739 frequency of complaints about not finding RTTI symbols. In addition,
2740 if you are stopped at inside of a function defined within a namespace,
2741 GDB modifies its name lookup accordingly.
2743 * New native configurations
2745 NetBSD/amd64 x86_64-*-netbsd*
2746 OpenBSD/amd64 x86_64-*-openbsd*
2747 OpenBSD/alpha alpha*-*-openbsd*
2748 OpenBSD/sparc sparc-*-openbsd*
2749 OpenBSD/sparc64 sparc64-*-openbsd*
2751 * New debugging protocols
2753 M32R with SDI protocol m32r-*-elf*
2755 * "set prompt-escape-char" command deleted.
2757 The command "set prompt-escape-char" has been deleted. This command,
2758 and its very obscure effet on GDB's prompt, was never documented,
2759 tested, nor mentioned in the NEWS file.
2761 * OBSOLETE configurations and files
2763 Configurations that have been declared obsolete in this release have
2764 been commented out. Unless there is activity to revive these
2765 configurations, the next release of GDB will have their sources
2766 permanently REMOVED.
2768 Sun 3, running SunOS 3 m68*-*-sunos3*
2769 Sun 3, running SunOS 4 m68*-*-sunos4*
2770 Sun 2, running SunOS 3 m68000-*-sunos3*
2771 Sun 2, running SunOS 4 m68000-*-sunos4*
2772 Motorola 680x0 running LynxOS m68*-*-lynxos*
2773 AT&T 3b1/Unix pc m68*-att-*
2774 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2775 decstation mips-dec-* mips-little-*
2776 riscos mips-*-riscos* mips-*-sysv*
2777 sonymips mips-sony-*
2778 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2780 * REMOVED configurations and files
2782 SGI Irix-4.x mips-sgi-irix4 or iris4
2783 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2784 Z8000 simulator z8k-zilog-none or z8ksim
2785 Matsushita MN10200 w/simulator mn10200-*-*
2786 H8/500 simulator h8500-hitachi-hms or h8500hms
2787 HP/PA running BSD hppa*-*-bsd*
2788 HP/PA running OSF/1 hppa*-*-osf*
2789 HP/PA Pro target hppa*-*-pro*
2790 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2791 386BSD i[3456]86-*-bsd*
2792 Sequent family i[3456]86-sequent-sysv4*
2793 i[3456]86-sequent-sysv*
2794 i[3456]86-sequent-bsd*
2795 SPARC running LynxOS sparc-*-lynxos*
2796 SPARC running SunOS 4 sparc-*-sunos4*
2797 Tsqware Sparclet sparclet-*-*
2798 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2800 *** Changes in GDB 6.0:
2804 Support for debugging the Objective-C programming language has been
2805 integrated into GDB.
2807 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2809 DWARF 2's Call Frame Information makes available compiler generated
2810 information that more exactly describes the program's run-time stack.
2811 By using this information, GDB is able to provide more robust stack
2814 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2815 have been updated to use a new backtrace mechanism which includes
2816 DWARF 2 CFI support.
2820 GDB's remote protocol has been extended to include support for hosted
2821 file I/O (where the remote target uses GDB's file system). See GDB's
2822 remote protocol documentation for details.
2824 * All targets using the new architecture framework.
2826 All of GDB's targets have been updated to use the new internal
2827 architecture framework. The way is now open for future GDB releases
2828 to include cross-architecture native debugging support (i386 on amd64,
2831 * GNU/Linux's Thread Local Storage (TLS)
2833 GDB now includes support for for the GNU/Linux implementation of
2834 per-thread variables.
2836 * GNU/Linux's Native POSIX Thread Library (NPTL)
2838 GDB's thread code has been updated to work with either the new
2839 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2841 * Separate debug info.
2843 GDB, in conjunction with BINUTILS, now supports a mechanism for
2844 automatically loading debug information from a separate file. Instead
2845 of shipping full debug and non-debug versions of system libraries,
2846 system integrators can now instead ship just the stripped libraries
2847 and optional debug files.
2849 * DWARF 2 Location Expressions
2851 DWARF 2 Location Expressions allow the compiler to more completely
2852 describe the location of variables (even in optimized code) to the
2855 GDB now includes preliminary support for location expressions (support
2856 for DW_OP_piece is still missing).
2860 A number of long standing bugs that caused GDB to die while starting a
2861 Java application have been fixed. GDB's Java support is now
2862 considered "useable".
2864 * GNU/Linux support for fork, vfork, and exec.
2866 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2867 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2870 * GDB supports logging output to a file
2872 There are two new commands, "set logging" and "show logging", which can be
2873 used to capture GDB's output to a file.
2875 * The meaning of "detach" has changed for gdbserver
2877 The "detach" command will now resume the application, as documented. To
2878 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2881 * d10v, m68hc11 `regs' command deprecated
2883 The `info registers' command has been updated so that it displays the
2884 registers using a format identical to the old `regs' command.
2888 A new command, "maint set profile on/off", has been added. This command can
2889 be used to enable or disable profiling while running GDB, to profile a
2890 session or a set of commands. In addition there is a new configure switch,
2891 "--enable-profiling", which will cause GDB to be compiled with profiling
2892 data, for more informative profiling results.
2894 * Default MI syntax changed to "mi2".
2896 The default MI (machine interface) syntax, enabled by the command line
2897 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2898 "mi1", can be enabled by specifying the option "-i=mi1".
2900 Support for the original "mi0" syntax (included in GDB 5.0) has been
2903 Fix for gdb/192: removed extraneous space when displaying frame level.
2904 Fix for gdb/672: update changelist is now output in mi list format.
2905 Fix for gdb/702: a -var-assign that updates the value now shows up
2906 in a subsequent -var-update.
2908 * New native configurations.
2910 FreeBSD/amd64 x86_64-*-freebsd*
2912 * Multi-arched targets.
2914 HP/PA HPUX11 hppa*-*-hpux*
2915 Renesas M32R/D w/simulator m32r-*-elf*
2917 * OBSOLETE configurations and files
2919 Configurations that have been declared obsolete in this release have
2920 been commented out. Unless there is activity to revive these
2921 configurations, the next release of GDB will have their sources
2922 permanently REMOVED.
2924 Z8000 simulator z8k-zilog-none or z8ksim
2925 Matsushita MN10200 w/simulator mn10200-*-*
2926 H8/500 simulator h8500-hitachi-hms or h8500hms
2927 HP/PA running BSD hppa*-*-bsd*
2928 HP/PA running OSF/1 hppa*-*-osf*
2929 HP/PA Pro target hppa*-*-pro*
2930 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2931 Sequent family i[3456]86-sequent-sysv4*
2932 i[3456]86-sequent-sysv*
2933 i[3456]86-sequent-bsd*
2934 Tsqware Sparclet sparclet-*-*
2935 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2937 * REMOVED configurations and files
2940 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2941 IBM AIX PS/2 i[3456]86-*-aix
2942 i386 running Mach 3.0 i[3456]86-*-mach3*
2943 i386 running Mach i[3456]86-*-mach*
2944 i386 running OSF/1 i[3456]86-*osf1mk*
2945 HP/Apollo 68k Family m68*-apollo*-sysv*,
2947 m68*-hp-bsd*, m68*-hp-hpux*
2948 Argonaut Risc Chip (ARC) arc-*-*
2949 Mitsubishi D30V d30v-*-*
2950 Fujitsu FR30 fr30-*-elf*
2951 OS/9000 i[34]86-*-os9k
2952 I960 with MON960 i960-*-coff
2954 * MIPS $fp behavior changed
2956 The convenience variable $fp, for the MIPS, now consistently returns
2957 the address of the current frame's base. Previously, depending on the
2958 context, $fp could refer to either $sp or the current frame's base
2959 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2960 The GNU Source-Level Debugger''.
2962 *** Changes in GDB 5.3:
2964 * GNU/Linux shared library multi-threaded performance improved.
2966 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2967 `/proc', in preference to `ptrace' for memory reads. This may result
2968 in an improvement in the start-up time of multi-threaded, shared
2969 library applications when run under GDB. One GDB user writes: ``loads
2970 shared libs like mad''.
2972 * ``gdbserver'' now supports multi-threaded applications on some targets
2974 Support for debugging multi-threaded applications which use
2975 the GNU/Linux LinuxThreads package has been added for
2976 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2977 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2979 * GDB now supports C/C++ preprocessor macros.
2981 GDB now expands preprocessor macro invocations in C/C++ expressions,
2982 and provides various commands for showing macro definitions and how
2985 The new command `macro expand EXPRESSION' expands any macro
2986 invocations in expression, and shows the result.
2988 The new command `show macro MACRO-NAME' shows the definition of the
2989 macro named MACRO-NAME, and where it was defined.
2991 Most compilers don't include information about macros in the debugging
2992 information by default. In GCC 3.1, for example, you need to compile
2993 your program with the options `-gdwarf-2 -g3'. If the macro
2994 information is present in the executable, GDB will read it.
2996 * Multi-arched targets.
2998 DEC Alpha (partial) alpha*-*-*
2999 DEC VAX (partial) vax-*-*
3001 National Semiconductor NS32000 (partial) ns32k-*-*
3002 Motorola 68000 (partial) m68k-*-*
3003 Motorola MCORE mcore-*-*
3007 Fujitsu FRV architecture added by Red Hat frv*-*-*
3010 * New native configurations
3012 Alpha NetBSD alpha*-*-netbsd*
3013 SH NetBSD sh*-*-netbsdelf*
3014 MIPS NetBSD mips*-*-netbsd*
3015 UltraSPARC NetBSD sparc64-*-netbsd*
3017 * OBSOLETE configurations and files
3019 Configurations that have been declared obsolete in this release have
3020 been commented out. Unless there is activity to revive these
3021 configurations, the next release of GDB will have their sources
3022 permanently REMOVED.
3024 Mitsubishi D30V d30v-*-*
3025 OS/9000 i[34]86-*-os9k
3026 IBM AIX PS/2 i[3456]86-*-aix
3027 Fujitsu FR30 fr30-*-elf*
3028 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3029 Argonaut Risc Chip (ARC) arc-*-*
3030 i386 running Mach 3.0 i[3456]86-*-mach3*
3031 i386 running Mach i[3456]86-*-mach*
3032 i386 running OSF/1 i[3456]86-*osf1mk*
3033 HP/Apollo 68k Family m68*-apollo*-sysv*,
3035 m68*-hp-bsd*, m68*-hp-hpux*
3036 I960 with MON960 i960-*-coff
3038 * OBSOLETE languages
3040 CHILL, a Pascal like language used by telecommunications companies.
3042 * REMOVED configurations and files
3044 AMD 29k family via UDI a29k-amd-udi, udi29k
3045 A29K VxWorks a29k-*-vxworks
3046 AMD 29000 embedded, using EBMON a29k-none-none
3047 AMD 29000 embedded with COFF a29k-none-coff
3048 AMD 29000 embedded with a.out a29k-none-aout
3050 testsuite/gdb.hp/gdb.threads-hp/ directory
3052 * New command "set max-user-call-depth <nnn>"
3054 This command allows the user to limit the call depth of user-defined
3055 commands. The default is 1024.
3057 * Changes in FreeBSD/i386 native debugging.
3059 Support for the "generate-core-file" has been added.
3061 * New commands "dump", "append", and "restore".
3063 These commands allow data to be copied from target memory
3064 to a bfd-format or binary file (dump and append), and back
3065 from a file into memory (restore).
3067 * Improved "next/step" support on multi-processor Alpha Tru64.
3069 The previous single-step mechanism could cause unpredictable problems,
3070 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3071 of a software single-step mechanism prevents this.
3073 *** Changes in GDB 5.2.1:
3081 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3082 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3083 Fix, by Joel Brobecker imported from mainline.
3085 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3086 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3087 Fix, by Fred Fish, imported from mainline.
3089 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3090 Surprisingly enough, it works now.
3091 By Michal Ludvig, imported from mainline.
3093 i386 hardware watchpoint support:
3094 avoid misses on second run for some targets.
3095 By Pierre Muller, imported from mainline.
3097 *** Changes in GDB 5.2:
3099 * New command "set trust-readonly-sections on[off]".
3101 This command is a hint that tells gdb that read-only sections
3102 really are read-only (ie. that their contents will not change).
3103 In this mode, gdb will go to the object file rather than the
3104 target to read memory from read-only sections (such as ".text").
3105 This can be a significant performance improvement on some
3106 (notably embedded) targets.
3108 * New command "generate-core-file" (or "gcore").
3110 This new gdb command allows the user to drop a core file of the child
3111 process state at any time. So far it's been implemented only for
3112 GNU/Linux and Solaris, but should be relatively easily ported to other
3113 hosts. Argument is core file name (defaults to core.<pid>).
3115 * New command line option
3117 GDB now accepts --pid or -p followed by a process id.
3119 * Change in command line behavior -- corefiles vs. process ids.
3121 There is a subtle behavior in the way in which GDB handles
3122 command line arguments. The first non-flag argument is always
3123 a program to debug, but the second non-flag argument may either
3124 be a corefile or a process id. Previously, GDB would attempt to
3125 open the second argument as a corefile, and if that failed, would
3126 issue a superfluous error message and then attempt to attach it as
3127 a process. Now, if the second argument begins with a non-digit,
3128 it will be treated as a corefile. If it begins with a digit,
3129 GDB will attempt to attach it as a process, and if no such process
3130 is found, will then attempt to open it as a corefile.
3132 * Changes in ARM configurations.
3134 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3135 configuration is fully multi-arch.
3137 * New native configurations
3139 ARM NetBSD arm*-*-netbsd*
3140 x86 OpenBSD i[3456]86-*-openbsd*
3141 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3142 Sparc64 running FreeBSD sparc64-*-freebsd*
3146 Sanyo XStormy16 xstormy16-elf
3148 * OBSOLETE configurations and files
3150 Configurations that have been declared obsolete in this release have
3151 been commented out. Unless there is activity to revive these
3152 configurations, the next release of GDB will have their sources
3153 permanently REMOVED.
3155 AMD 29k family via UDI a29k-amd-udi, udi29k
3156 A29K VxWorks a29k-*-vxworks
3157 AMD 29000 embedded, using EBMON a29k-none-none
3158 AMD 29000 embedded with COFF a29k-none-coff
3159 AMD 29000 embedded with a.out a29k-none-aout
3161 testsuite/gdb.hp/gdb.threads-hp/ directory
3163 * REMOVED configurations and files
3165 TI TMS320C80 tic80-*-*
3167 PowerPC Solaris powerpcle-*-solaris*
3168 PowerPC Windows NT powerpcle-*-cygwin32
3169 PowerPC Netware powerpc-*-netware*
3170 Harris/CXUX m88k m88*-harris-cxux*
3171 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3172 ns32k-utek-sysv* ns32k-utek-*
3173 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3174 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3175 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3176 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3177 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3179 * Changes to command line processing
3181 The new `--args' feature can be used to specify command-line arguments
3182 for the inferior from gdb's command line.
3184 * Changes to key bindings
3186 There is a new `operate-and-get-next' function bound to `C-o'.
3188 *** Changes in GDB 5.1.1
3190 Fix compile problem on DJGPP.
3192 Fix a problem with floating-point registers on the i386 being
3195 Fix to stop GDB crashing on .debug_str debug info.
3197 Numerous documentation fixes.
3199 Numerous testsuite fixes.
3201 *** Changes in GDB 5.1:
3203 * New native configurations
3205 Alpha FreeBSD alpha*-*-freebsd*
3206 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3207 MIPS GNU/Linux mips*-*-linux*
3208 MIPS SGI Irix 6.x mips*-sgi-irix6*
3209 ia64 AIX ia64-*-aix*
3210 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3214 Motorola 68HC11 and 68HC12 m68hc11-elf
3216 UltraSparc running GNU/Linux sparc64-*-linux*
3218 * OBSOLETE configurations and files
3220 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3221 Harris/CXUX m88k m88*-harris-cxux*
3222 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3223 ns32k-utek-sysv* ns32k-utek-*
3224 TI TMS320C80 tic80-*-*
3226 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3227 PowerPC Solaris powerpcle-*-solaris*
3228 PowerPC Windows NT powerpcle-*-cygwin32
3229 PowerPC Netware powerpc-*-netware*
3230 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3231 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3232 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3233 Apple Macintosh (MPW) host N/A
3235 stuff.c (Program to stuff files into a specially prepared space in kdb)
3236 kdb-start.c (Main loop for the standalone kernel debugger)
3238 Configurations that have been declared obsolete in this release have
3239 been commented out. Unless there is activity to revive these
3240 configurations, the next release of GDB will have their sources
3241 permanently REMOVED.
3243 * REMOVED configurations and files
3245 Altos 3068 m68*-altos-*
3246 Convex c1-*-*, c2-*-*
3248 ARM RISCix arm-*-* (as host)
3252 * GDB has been converted to ISO C.
3254 GDB's source code has been converted to ISO C. In particular, the
3255 sources are fully protoized, and rely on standard headers being
3260 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3262 * The MI enabled by default.
3264 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3265 revised and enabled by default. Packages which use GDB as a debugging
3266 engine behind a UI or another front end are encouraged to switch to
3267 using the GDB/MI interface, instead of the old annotations interface
3268 which is now deprecated.
3270 * Support for debugging Pascal programs.
3272 GDB now includes support for debugging Pascal programs. The following
3273 main features are supported:
3275 - Pascal-specific data types such as sets;
3277 - automatic recognition of Pascal sources based on file-name
3280 - Pascal-style display of data types, variables, and functions;
3282 - a Pascal expression parser.
3284 However, some important features are not yet supported.
3286 - Pascal string operations are not supported at all;
3288 - there are some problems with boolean types;
3290 - Pascal type hexadecimal constants are not supported
3291 because they conflict with the internal variables format;
3293 - support for Pascal objects and classes is not full yet;
3295 - unlike Pascal, GDB is case-sensitive for symbol names.
3297 * Changes in completion.
3299 Commands such as `shell', `run' and `set args', which pass arguments
3300 to inferior programs, now complete on file names, similar to what
3301 users expect at the shell prompt.
3303 Commands which accept locations, such as `disassemble', `print',
3304 `breakpoint', `until', etc. now complete on filenames as well as
3305 program symbols. Thus, if you type "break foob TAB", and the source
3306 files linked into the programs include `foobar.c', that file name will
3307 be one of the candidates for completion. However, file names are not
3308 considered for completion after you typed a colon that delimits a file
3309 name from a name of a function in that file, as in "break foo.c:bar".
3311 `set demangle-style' completes on available demangling styles.
3313 * New platform-independent commands:
3315 It is now possible to define a post-hook for a command as well as a
3316 hook that runs before the command. For more details, see the
3317 documentation of `hookpost' in the GDB manual.
3319 * Changes in GNU/Linux native debugging.
3321 Support for debugging multi-threaded programs has been completely
3322 revised for all platforms except m68k and sparc. You can now debug as
3323 many threads as your system allows you to have.
3325 Attach/detach is supported for multi-threaded programs.
3327 Support for SSE registers was added for x86. This doesn't work for
3328 multi-threaded programs though.
3330 * Changes in MIPS configurations.
3332 Multi-arch support is enabled for all MIPS configurations.
3334 GDB can now be built as native debugger on SGI Irix 6.x systems for
3335 debugging n32 executables. (Debugging 64-bit executables is not yet
3338 * Unified support for hardware watchpoints in all x86 configurations.
3340 Most (if not all) native x86 configurations support hardware-assisted
3341 breakpoints and watchpoints in a unified manner. This support
3342 implements debug register sharing between watchpoints, which allows to
3343 put a virtually infinite number of watchpoints on the same address,
3344 and also supports watching regions up to 16 bytes with several debug
3347 The new maintenance command `maintenance show-debug-regs' toggles
3348 debugging print-outs in functions that insert, remove, and test
3349 watchpoints and hardware breakpoints.
3351 * Changes in the DJGPP native configuration.
3353 New command ``info dos sysinfo'' displays assorted information about
3354 the CPU, OS, memory, and DPMI server.
3356 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3357 display information about segment descriptors stored in GDT, LDT, and
3360 New commands ``info dos pde'' and ``info dos pte'' display entries
3361 from Page Directory and Page Tables (for now works with CWSDPMI only).
3362 New command ``info dos address-pte'' displays the Page Table entry for
3363 a given linear address.
3365 GDB can now pass command lines longer than 126 characters to the
3366 program being debugged (requires an update to the libdbg.a library
3367 which is part of the DJGPP development kit).
3369 DWARF2 debug info is now supported.
3371 It is now possible to `step' and `next' through calls to `longjmp'.
3373 * Changes in documentation.
3375 All GDB documentation was converted to GFDL, the GNU Free
3376 Documentation License.
3378 Tracepoints-related commands are now fully documented in the GDB
3381 TUI, the Text-mode User Interface, is now documented in the manual.
3383 Tracepoints-related commands are now fully documented in the GDB
3386 The "GDB Internals" manual now has an index. It also includes
3387 documentation of `ui_out' functions, GDB coding standards, x86
3388 hardware watchpoints, and memory region attributes.
3390 * GDB's version number moved to ``version.in''
3392 The Makefile variable VERSION has been replaced by the file
3393 ``version.in''. People creating GDB distributions should update the
3394 contents of this file.
3398 GUD support is now a standard part of the EMACS distribution.
3400 *** Changes in GDB 5.0:
3402 * Improved support for debugging FP programs on x86 targets
3404 Unified and much-improved support for debugging floating-point
3405 programs on all x86 targets. In particular, ``info float'' now
3406 displays the FP registers in the same format on all x86 targets, with
3407 greater level of detail.
3409 * Improvements and bugfixes in hardware-assisted watchpoints
3411 It is now possible to watch array elements, struct members, and
3412 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3413 on x86 targets no longer erroneously trigger when the address is
3416 * Improvements in the native DJGPP version of GDB
3418 The distribution now includes all the scripts and auxiliary files
3419 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3420 machines ``out of the box''.
3422 The DJGPP version can now debug programs that use signals. It is
3423 possible to catch signals that happened in the debuggee, deliver
3424 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3425 would kill the program being debugged.) Programs that hook hardware
3426 interrupts (keyboard, timer, etc.) can also be debugged.
3428 It is now possible to debug DJGPP programs that redirect their
3429 standard handles or switch them to raw (as opposed to cooked) mode, or
3430 even close them. The command ``run < foo > bar'' works as expected,
3431 and ``info terminal'' reports useful information about the debuggee's
3432 terminal, including raw/cooked mode, redirection, etc.
3434 The DJGPP version now uses termios functions for console I/O, which
3435 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3438 DOS-style file names with drive letters are now fully supported by
3441 It is now possible to debug DJGPP programs that switch their working
3442 directory. It is also possible to rerun the debuggee any number of
3443 times without restarting GDB; thus, you can use the same setup,
3444 breakpoints, etc. for many debugging sessions.
3446 * New native configurations
3448 ARM GNU/Linux arm*-*-linux*
3449 PowerPC GNU/Linux powerpc-*-linux*
3453 Motorola MCore mcore-*-*
3454 x86 VxWorks i[3456]86-*-vxworks*
3455 PowerPC VxWorks powerpc-*-vxworks*
3456 TI TMS320C80 tic80-*-*
3458 * OBSOLETE configurations
3460 Altos 3068 m68*-altos-*
3461 Convex c1-*-*, c2-*-*
3463 ARM RISCix arm-*-* (as host)
3466 Configurations that have been declared obsolete will be commented out,
3467 but the code will be left in place. If there is no activity to revive
3468 these configurations before the next release of GDB, the sources will
3469 be permanently REMOVED.
3471 * Gould support removed
3473 Support for the Gould PowerNode and NP1 has been removed.
3475 * New features for SVR4
3477 On SVR4 native platforms (such as Solaris), if you attach to a process
3478 without first loading a symbol file, GDB will now attempt to locate and
3479 load symbols from the running process's executable file.
3481 * Many C++ enhancements
3483 C++ support has been greatly improved. Overload resolution now works properly
3484 in almost all cases. RTTI support is on the way.
3486 * Remote targets can connect to a sub-program
3488 A popen(3) style serial-device has been added. This device starts a
3489 sub-process (such as a stand-alone simulator) and then communicates
3490 with that. The sub-program to run is specified using the syntax
3491 ``|<program> <args>'' vis:
3493 (gdb) set remotedebug 1
3494 (gdb) target extended-remote |mn10300-elf-sim program-args
3496 * MIPS 64 remote protocol
3498 A long standing bug in the mips64 remote protocol where by GDB
3499 expected certain 32 bit registers (ex SR) to be transfered as 32
3500 instead of 64 bits has been fixed.
3502 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3503 added to provide backward compatibility with older versions of GDB.
3505 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3507 The command ``set remotebinarydownload'' command has been replaced by
3508 ``set remote X-packet''. Other commands in ``set remote'' family
3509 include ``set remote P-packet''.
3511 * Breakpoint commands accept ranges.
3513 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3514 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3515 ``tracepoint passcount'' also accepts a range of tracepoints.
3517 * ``apropos'' command added.
3519 The ``apropos'' command searches through command names and
3520 documentation strings, printing out matches, making it much easier to
3521 try to find a command that does what you are looking for.
3525 A new machine oriented interface (MI) has been added to GDB. This
3526 interface is designed for debug environments running GDB as a separate
3527 process. This is part of the long term libGDB project. See the
3528 "GDB/MI" chapter of the GDB manual for further information. It can be
3529 enabled by configuring with:
3531 .../configure --enable-gdbmi
3533 *** Changes in GDB-4.18:
3535 * New native configurations
3537 HP-UX 10.20 hppa*-*-hpux10.20
3538 HP-UX 11.x hppa*-*-hpux11.0*
3539 M68K GNU/Linux m68*-*-linux*
3543 Fujitsu FR30 fr30-*-elf*
3544 Intel StrongARM strongarm-*-*
3545 Mitsubishi D30V d30v-*-*
3547 * OBSOLETE configurations
3549 Gould PowerNode, NP1 np1-*-*, pn-*-*
3551 Configurations that have been declared obsolete will be commented out,
3552 but the code will be left in place. If there is no activity to revive
3553 these configurations before the next release of GDB, the sources will
3554 be permanently REMOVED.
3558 As a compatibility experiment, GDB's source files buildsym.h and
3559 buildsym.c have been converted to pure standard C, no longer
3560 containing any K&R compatibility code. We believe that all systems in
3561 use today either come with a standard C compiler, or have a GCC port
3562 available. If this is not true, please report the affected
3563 configuration to bug-gdb@gnu.org immediately. See the README file for
3564 information about getting a standard C compiler if you don't have one
3569 GDB now uses readline 2.2.
3571 * set extension-language
3573 You can now control the mapping between filename extensions and source
3574 languages by using the `set extension-language' command. For instance,
3575 you can ask GDB to treat .c files as C++ by saying
3576 set extension-language .c c++
3577 The command `info extensions' lists all of the recognized extensions
3578 and their associated languages.
3580 * Setting processor type for PowerPC and RS/6000
3582 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3583 you can use the `set processor' command to specify what variant of the
3584 PowerPC family you are debugging. The command
3588 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3589 following PowerPC and RS6000 variants:
3591 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3592 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3594 403GC IBM PowerPC 403GC
3595 505 Motorola PowerPC 505
3596 860 Motorola PowerPC 860 or 850
3597 601 Motorola PowerPC 601
3598 602 Motorola PowerPC 602
3599 603 Motorola/IBM PowerPC 603 or 603e
3600 604 Motorola PowerPC 604 or 604e
3601 750 Motorola/IBM PowerPC 750 or 750
3603 At the moment, this command just tells GDB what to name the
3604 special-purpose processor registers. Since almost all the affected
3605 registers are inaccessible to user-level programs, this command is
3606 only useful for remote debugging in its present form.
3610 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3611 more extensive support for HP-UX. Added features include shared
3612 library support, kernel threads and hardware watchpoints for 11.00,
3613 support for HP's ANSI C and C++ compilers, and a compatibility mode
3614 for xdb and dbx commands.
3618 HP's donation includes the new concept of catchpoints, which is a
3619 generalization of the old catch command. On HP-UX, it is now possible
3620 to catch exec, fork, and vfork, as well as library loading.
3622 This means that the existing catch command has changed; its first
3623 argument now specifies the type of catch to be set up. See the
3624 output of "help catch" for a list of catchpoint types.
3626 * Debugging across forks
3628 On HP-UX, you can choose which process to debug when a fork() happens
3633 HP has donated a curses-based terminal user interface (TUI). To get
3634 it, build with --enable-tui. Although this can be enabled for any
3635 configuration, at present it only works for native HP debugging.
3637 * GDB remote protocol additions
3639 A new protocol packet 'X' that writes binary data is now available.
3640 Default behavior is to try 'X', then drop back to 'M' if the stub
3641 fails to respond. The settable variable `remotebinarydownload'
3642 allows explicit control over the use of 'X'.
3644 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3645 full 64-bit address. The command
3647 set remoteaddresssize 32
3649 can be used to revert to the old behaviour. For existing remote stubs
3650 the change should not be noticed, as the additional address information
3653 In order to assist in debugging stubs, you may use the maintenance
3654 command `packet' to send any text string to the stub. For instance,
3656 maint packet heythere
3658 sends the packet "$heythere#<checksum>". Note that it is very easy to
3659 disrupt a debugging session by sending the wrong packet at the wrong
3662 The compare-sections command allows you to compare section data on the
3663 target to what is in the executable file without uploading or
3664 downloading, by comparing CRC checksums.
3666 * Tracing can collect general expressions
3668 You may now collect general expressions at tracepoints. This requires
3669 further additions to the target-side stub; see tracepoint.c and
3670 doc/agentexpr.texi for further details.
3672 * mask-address variable for Mips
3674 For Mips targets, you may control the zeroing of the upper 32 bits of
3675 a 64-bit address by entering `set mask-address on'. This is mainly
3676 of interest to users of embedded R4xxx and R5xxx processors.
3678 * Higher serial baud rates
3680 GDB's serial code now allows you to specify baud rates 57600, 115200,
3681 230400, and 460800 baud. (Note that your host system may not be able
3682 to achieve all of these rates.)
3686 The i960 configuration now includes an initial implementation of a
3687 builtin simulator, contributed by Jim Wilson.
3690 *** Changes in GDB-4.17:
3692 * New native configurations
3694 Alpha GNU/Linux alpha*-*-linux*
3695 Unixware 2.x i[3456]86-unixware2*
3696 Irix 6.x mips*-sgi-irix6*
3697 PowerPC GNU/Linux powerpc-*-linux*
3698 PowerPC Solaris powerpcle-*-solaris*
3699 Sparc GNU/Linux sparc-*-linux*
3700 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3704 Argonaut Risc Chip (ARC) arc-*-*
3705 Hitachi H8/300S h8300*-*-*
3706 Matsushita MN10200 w/simulator mn10200-*-*
3707 Matsushita MN10300 w/simulator mn10300-*-*
3708 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3709 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3710 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3711 Mitsubishi D10V w/simulator d10v-*-*
3712 Mitsubishi M32R/D w/simulator m32r-*-elf*
3713 Tsqware Sparclet sparclet-*-*
3714 NEC V850 w/simulator v850-*-*
3716 * New debugging protocols
3718 ARM with RDI protocol arm*-*-*
3719 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3720 DDB and LSI variants of PMON protocol mips*-*-*
3721 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3722 PowerPC with SDS protocol powerpc{,le}-*-eabi
3723 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3727 All configurations can now understand and use the DWARF 2 debugging
3728 format. The choice is automatic, if the symbol file contains DWARF 2
3733 GDB now includes basic Java language support. This support is
3734 only useful with Java compilers that produce native machine code.
3736 * solib-absolute-prefix and solib-search-path
3738 For SunOS and SVR4 shared libraries, you may now set the prefix for
3739 loading absolute shared library symbol files, and the search path for
3740 locating non-absolute shared library symbol files.
3742 * Live range splitting
3744 GDB can now effectively debug code for which GCC has performed live
3745 range splitting as part of its optimization. See gdb/doc/LRS for
3746 more details on the expected format of the stabs information.
3750 GDB's support for the GNU Hurd, including thread debugging, has been
3751 updated to work with current versions of the Hurd.
3755 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3756 instruction set. ARM GDB automatically detects when Thumb
3757 instructions are in use, and adjusts disassembly and backtracing
3762 GDB's MIPS target configurations now handle the MIP16 16-bit
3767 GDB now includes support for overlays; if an executable has been
3768 linked such that multiple sections are based at the same address, GDB
3769 will decide which section to use for symbolic info. You can choose to
3770 control the decision manually, using overlay commands, or implement
3771 additional target-side support and use "overlay load-target" to bring
3772 in the overlay mapping. Do "help overlay" for more detail.
3776 The command "info symbol <address>" displays information about
3777 the symbol at the specified address.
3781 The standard remote protocol now includes an extension that allows
3782 asynchronous collection and display of trace data. This requires
3783 extensive support in the target-side debugging stub. Tracing mode
3784 includes a new interaction mode in GDB and new commands: see the
3785 file tracepoint.c for more details.
3789 Configurations for embedded MIPS now include a simulator contributed
3790 by Cygnus Solutions. The simulator supports the instruction sets
3791 of most MIPS variants.
3795 Sparc configurations may now include the ERC32 simulator contributed
3796 by the European Space Agency. The simulator is not built into
3797 Sparc targets by default; configure with --enable-sim to include it.
3801 For target configurations that may include multiple variants of a
3802 basic architecture (such as MIPS and SH), you may now set the
3803 architecture explicitly. "set arch" sets, "info arch" lists
3804 the possible architectures.
3806 *** Changes in GDB-4.16:
3808 * New native configurations
3810 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3811 M68K NetBSD m68k-*-netbsd*
3812 PowerPC AIX 4.x powerpc-*-aix*
3813 PowerPC MacOS powerpc-*-macos*
3814 PowerPC Windows NT powerpcle-*-cygwin32
3815 RS/6000 AIX 4.x rs6000-*-aix4*
3819 ARM with RDP protocol arm-*-*
3820 I960 with MON960 i960-*-coff
3821 MIPS VxWorks mips*-*-vxworks*
3822 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3823 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3825 Matra Sparclet sparclet-*-*
3829 The powerpc-eabi configuration now includes the PSIM simulator,
3830 contributed by Andrew Cagney, with assistance from Mike Meissner.
3831 PSIM is a very elaborate model of the PowerPC, including not only
3832 basic instruction set execution, but also details of execution unit
3833 performance and I/O hardware. See sim/ppc/README for more details.
3837 GDB now works with Solaris 2.5.
3839 * Windows 95/NT native
3841 GDB will now work as a native debugger on Windows 95 and Windows NT.
3842 To build it from source, you must use the "gnu-win32" environment,
3843 which uses a DLL to emulate enough of Unix to run the GNU tools.
3844 Further information, binaries, and sources are available at
3845 ftp.cygnus.com, under pub/gnu-win32.
3847 * dont-repeat command
3849 If a user-defined command includes the command `dont-repeat', then the
3850 command will not be repeated if the user just types return. This is
3851 useful if the command is time-consuming to run, so that accidental
3852 extra keystrokes don't run the same command many times.
3854 * Send break instead of ^C
3856 The standard remote protocol now includes an option to send a break
3857 rather than a ^C to the target in order to interrupt it. By default,
3858 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3860 * Remote protocol timeout
3862 The standard remote protocol includes a new variable `remotetimeout'
3863 that allows you to set the number of seconds before GDB gives up trying
3864 to read from the target. The default value is 2.
3866 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3868 By default GDB will automatically keep track of objects as they are
3869 loaded and unloaded by the dynamic linker. By using the command `set
3870 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3871 when shared library events occur, thus allowing you to set breakpoints
3872 in shared libraries which are explicitly loaded by the inferior.
3874 Note this feature does not work on hpux8. On hpux9 you must link
3875 /usr/lib/end.o into your program. This feature should work
3876 automatically on hpux10.
3878 * Irix 5.x hardware watchpoint support
3880 Irix 5 configurations now support the use of hardware watchpoints.
3882 * Mips protocol "SYN garbage limit"
3884 When debugging a Mips target using the `target mips' protocol, you
3885 may set the number of characters that GDB will ignore by setting
3886 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3887 every character. The default value is 1050.
3889 * Recording and replaying remote debug sessions
3891 If you set `remotelogfile' to the name of a file, gdb will write to it
3892 a recording of a remote debug session. This recording may then be
3893 replayed back to gdb using "gdbreplay". See gdbserver/README for
3894 details. This is useful when you have a problem with GDB while doing
3895 remote debugging; you can make a recording of the session and send it
3896 to someone else, who can then recreate the problem.
3898 * Speedups for remote debugging
3900 GDB includes speedups for downloading and stepping MIPS systems using
3901 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3902 and more efficient S-record downloading.
3904 * Memory use reductions and statistics collection
3906 GDB now uses less memory and reports statistics about memory usage.
3907 Try the `maint print statistics' command, for example.
3909 *** Changes in GDB-4.15:
3911 * Psymtabs for XCOFF
3913 The symbol reader for AIX GDB now uses partial symbol tables. This
3914 can greatly improve startup time, especially for large executables.
3916 * Remote targets use caching
3918 Remote targets now use a data cache to speed up communication with the
3919 remote side. The data cache could lead to incorrect results because
3920 it doesn't know about volatile variables, thus making it impossible to
3921 debug targets which use memory mapped I/O devices. `set remotecache
3922 off' turns the the data cache off.
3924 * Remote targets may have threads
3926 The standard remote protocol now includes support for multiple threads
3927 in the target system, using new protocol commands 'H' and 'T'. See
3928 gdb/remote.c for details.
3932 If GDB is configured with `--enable-netrom', then it will include
3933 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3934 acts as though it is a bank of ROM on the target board, but you can
3935 write into it over the network. GDB's support consists only of
3936 support for fast loading into the emulated ROM; to debug, you must use
3937 another protocol, such as standard remote protocol. The usual
3938 sequence is something like
3940 target nrom <netrom-hostname>
3942 target remote <netrom-hostname>:1235
3946 GDB now includes support for the Apple Macintosh, as a host only. It
3947 may be run as either an MPW tool or as a standalone application, and
3948 it can debug through the serial port. All the usual GDB commands are
3949 available, but to the target command, you must supply "serial" as the
3950 device type instead of "/dev/ttyXX". See mpw-README in the main
3951 directory for more information on how to build. The MPW configuration
3952 scripts */mpw-config.in support only a few targets, and only the
3953 mips-idt-ecoff target has been tested.
3957 GDB configuration now uses autoconf. This is not user-visible,
3958 but does simplify configuration and building.
3962 GDB now supports hpux10.
3964 *** Changes in GDB-4.14:
3966 * New native configurations
3968 x86 FreeBSD i[345]86-*-freebsd
3969 x86 NetBSD i[345]86-*-netbsd
3970 NS32k NetBSD ns32k-*-netbsd
3971 Sparc NetBSD sparc-*-netbsd
3975 A29K VxWorks a29k-*-vxworks
3976 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3977 CPU32 EST-300 emulator m68*-*-est*
3978 PowerPC ELF powerpc-*-elf
3981 * Alpha OSF/1 support for procfs
3983 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3984 possible to attach to running processes. As the mounting of the /proc
3985 filesystem is optional on the Alpha, GDB automatically determines
3986 the availability of /proc during startup. This can lead to problems
3987 if /proc is unmounted after GDB has been started.
3989 * Arguments to user-defined commands
3991 User commands may accept up to 10 arguments separated by whitespace.
3992 Arguments are accessed within the user command via $arg0..$arg9. A
3995 print $arg0 + $arg1 + $arg2
3997 To execute the command use:
4000 Defines the command "adder" which prints the sum of its three arguments.
4001 Note the arguments are text substitutions, so they may reference variables,
4002 use complex expressions, or even perform inferior function calls.
4004 * New `if' and `while' commands
4006 This makes it possible to write more sophisticated user-defined
4007 commands. Both commands take a single argument, which is the
4008 expression to evaluate, and must be followed by the commands to
4009 execute, one per line, if the expression is nonzero, the list being
4010 terminated by the word `end'. The `if' command list may include an
4011 `else' word, which causes the following commands to be executed only
4012 if the expression is zero.
4014 * Fortran source language mode
4016 GDB now includes partial support for Fortran 77. It will recognize
4017 Fortran programs and can evaluate a subset of Fortran expressions, but
4018 variables and functions may not be handled correctly. GDB will work
4019 with G77, but does not yet know much about symbols emitted by other
4022 * Better HPUX support
4024 Most debugging facilities now work on dynamic executables for HPPAs
4025 running hpux9 or later. You can attach to running dynamically linked
4026 processes, but by default the dynamic libraries will be read-only, so
4027 for instance you won't be able to put breakpoints in them. To change
4028 that behavior do the following before running the program:
4034 This will cause the libraries to be mapped private and read-write.
4035 To revert to the normal behavior, do this:
4041 You cannot set breakpoints or examine data in the library until after
4042 the library is loaded if the function/data symbols do not have
4045 GDB can now also read debug symbols produced by the HP C compiler on
4046 HPPAs (sorry, no C++, Fortran or 68k support).
4048 * Target byte order now dynamically selectable
4050 You can choose which byte order to use with a target system, via the
4051 commands "set endian big" and "set endian little", and you can see the
4052 current setting by using "show endian". You can also give the command
4053 "set endian auto", in which case GDB will use the byte order
4054 associated with the executable. Currently, only embedded MIPS
4055 configurations support dynamic selection of target byte order.
4057 * New DOS host serial code
4059 This version uses DPMI interrupts to handle buffered I/O, so you
4060 no longer need to run asynctsr when debugging boards connected to
4063 *** Changes in GDB-4.13:
4065 * New "complete" command
4067 This lists all the possible completions for the rest of the line, if it
4068 were to be given as a command itself. This is intended for use by emacs.
4070 * Trailing space optional in prompt
4072 "set prompt" no longer adds a space for you after the prompt you set. This
4073 allows you to set a prompt which ends in a space or one that does not.
4075 * Breakpoint hit counts
4077 "info break" now displays a count of the number of times the breakpoint
4078 has been hit. This is especially useful in conjunction with "ignore"; you
4079 can ignore a large number of breakpoint hits, look at the breakpoint info
4080 to see how many times the breakpoint was hit, then run again, ignoring one
4081 less than that number, and this will get you quickly to the last hit of
4084 * Ability to stop printing at NULL character
4086 "set print null-stop" will cause GDB to stop printing the characters of
4087 an array when the first NULL is encountered. This is useful when large
4088 arrays actually contain only short strings.
4090 * Shared library breakpoints
4092 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4093 breakpoints in shared libraries before the executable is run.
4095 * Hardware watchpoints
4097 There is a new hardware breakpoint for the watch command for sparclite
4098 targets. See gdb/sparclite/hw_breakpoint.note.
4100 Hardware watchpoints are also now supported under GNU/Linux.
4104 Annotations have been added. These are for use with graphical interfaces,
4105 and are still experimental. Currently only gdba.el uses these.
4107 * Improved Irix 5 support
4109 GDB now works properly with Irix 5.2.
4111 * Improved HPPA support
4113 GDB now works properly with the latest GCC and GAS.
4115 * New native configurations
4117 Sequent PTX4 i[34]86-sequent-ptx4
4118 HPPA running OSF/1 hppa*-*-osf*
4119 Atari TT running SVR4 m68*-*-sysv4*
4120 RS/6000 LynxOS rs6000-*-lynxos*
4124 OS/9000 i[34]86-*-os9k
4125 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4128 * Hitachi SH7000 and E7000-PC ICE support
4130 There is now support for communicating with the Hitachi E7000-PC ICE.
4131 This is available automatically when GDB is configured for the SH.
4135 As usual, a variety of small fixes and improvements, both generic
4136 and configuration-specific. See the ChangeLog for more detail.
4138 *** Changes in GDB-4.12:
4140 * Irix 5 is now supported
4144 GDB-4.12 on the HPPA has a number of changes which make it unable
4145 to debug the output from the currently released versions of GCC and
4146 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4147 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4148 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4151 *** Changes in GDB-4.11:
4153 * User visible changes:
4157 The "set remotedebug" option is now consistent between the mips remote
4158 target, remote targets using the gdb-specific protocol, UDI (AMD's
4159 debug protocol for the 29k) and the 88k bug monitor. It is now an
4160 integer specifying a debug level (normally 0 or 1, but 2 means more
4161 debugging info for the mips target).
4163 * DEC Alpha native support
4165 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4166 debug info, but GDB works fairly well with the DEC compiler and should
4167 work with a future GCC release. See the README file for a few
4168 Alpha-specific notes.
4170 * Preliminary thread implementation
4172 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4174 * LynxOS native and target support for 386
4176 This release has been hosted on LynxOS 2.2, and also can be configured
4177 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4180 * Improvements in C++ mangling/demangling.
4182 This release has much better g++ debugging, specifically in name
4183 mangling/demangling, virtual function calls, print virtual table,
4184 call methods, ...etc.
4186 *** Changes in GDB-4.10:
4188 * User visible changes:
4190 Remote debugging using the GDB-specific (`target remote') protocol now
4191 supports the `load' command. This is only useful if you have some
4192 other way of getting the stub to the target system, and you can put it
4193 somewhere in memory where it won't get clobbered by the download.
4195 Filename completion now works.
4197 When run under emacs mode, the "info line" command now causes the
4198 arrow to point to the line specified. Also, "info line" prints
4199 addresses in symbolic form (as well as hex).
4201 All vxworks based targets now support a user settable option, called
4202 vxworks-timeout. This option represents the number of seconds gdb
4203 should wait for responses to rpc's. You might want to use this if
4204 your vxworks target is, perhaps, a slow software simulator or happens
4205 to be on the far side of a thin network line.
4209 This release contains support for using a DEC alpha as a GDB host for
4210 cross debugging. Native alpha debugging is not supported yet.
4213 *** Changes in GDB-4.9:
4217 This is the first GDB release which is accompanied by a matching testsuite.
4218 The testsuite requires installation of dejagnu, which should be available
4219 via ftp from most sites that carry GNU software.
4223 'Cfront' style demangling has had its name changed to 'ARM' style, to
4224 emphasize that it was written from the specifications in the C++ Annotated
4225 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4226 disclaimers, it still generated too much confusion with users attempting to
4227 use gdb with AT&T cfront.
4231 GDB now uses a standard remote interface to a simulator library.
4232 So far, the library contains simulators for the Zilog Z8001/2, the
4233 Hitachi H8/300, H8/500 and Super-H.
4235 * New targets supported
4237 H8/300 simulator h8300-hitachi-hms or h8300hms
4238 H8/500 simulator h8500-hitachi-hms or h8500hms
4239 SH simulator sh-hitachi-hms or sh
4240 Z8000 simulator z8k-zilog-none or z8ksim
4241 IDT MIPS board over serial line mips-idt-ecoff
4243 Cross-debugging to GO32 targets is supported. It requires a custom
4244 version of the i386-stub.c module which is integrated with the
4245 GO32 memory extender.
4247 * New remote protocols
4249 MIPS remote debugging protocol.
4251 * New source languages supported
4253 This version includes preliminary support for Chill, a Pascal like language
4254 used by telecommunications companies. Chill support is also being integrated
4255 into the GNU compiler, but we don't know when it will be publically available.
4258 *** Changes in GDB-4.8:
4260 * HP Precision Architecture supported
4262 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4263 version of this support was available as a set of patches from the
4264 University of Utah. GDB does not support debugging of programs
4265 compiled with the HP compiler, because HP will not document their file
4266 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4267 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4269 Many problems in the preliminary version have been fixed.
4271 * Faster and better demangling
4273 We have improved template demangling and fixed numerous bugs in the GNU style
4274 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4275 character types (wchar_t) are now supported. Demangling of each symbol is now
4276 only done once, and is cached when the symbol table for a file is read in.
4277 This results in a small increase in memory usage for C programs, a moderate
4278 increase in memory usage for C++ programs, and a fantastic speedup in
4281 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4282 from the specifications in the Annotated Reference Manual, which AT&T's
4283 compiler does not actually implement.
4285 * G++ multiple inheritance compiler problem
4287 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4288 inheritance lattices was reworked to properly discover ambiguities. We
4289 recently found an example which causes this new algorithm to fail in a
4290 very subtle way, producing bad debug information for those classes.
4291 The file 'gcc.patch' (in this directory) can be applied to gcc to
4292 circumvent the problem. A future GCC release will contain a complete
4295 The previous G++ debug info problem (mentioned below for the gdb-4.7
4296 release) is fixed in gcc version 2.3.2.
4298 * Improved configure script
4300 The `configure' script will now attempt to guess your system type if
4301 you don't supply a host system type. The old scheme of supplying a
4302 host system triplet is preferable over using this. All the magic is
4303 done in the new `config.guess' script. Examine it for details.
4305 We have also brought our configure script much more in line with the FSF's
4306 version. It now supports the --with-xxx options. In particular,
4307 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4308 The resulting GDB will not be able to read arbitrary object file formats --
4309 only the format ``expected'' to be used on the configured target system.
4310 We hope to make this the default in a future release.
4312 * Documentation improvements
4314 There's new internal documentation on how to modify GDB, and how to
4315 produce clean changes to the code. We implore people to read it
4316 before submitting changes.
4318 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4319 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4320 `info' files are also provided. To build `info' files from scratch,
4321 you will need the latest `makeinfo' release, which will be available in
4322 a future texinfo-X.Y release.
4324 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4325 We're not sure exactly which versions have this problem, but it has
4326 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4327 or better. If that isn't possible, there is a patch in
4328 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4329 around this problem.
4333 GDB now supports array constants that can be used in expressions typed in by
4334 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4335 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4338 The new directory `gdb/sparclite' contains a program that demonstrates
4339 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4341 * New native hosts supported
4343 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4344 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4346 * New targets supported
4348 AMD 29k family via UDI a29k-amd-udi or udi29k
4350 * New file formats supported
4352 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4353 HPUX core files, and SCO 3.2v2 core files.
4357 Attaching to processes now works again; thanks for the many bug reports.
4359 We have also stomped on a bunch of core dumps caused by
4360 printf_filtered("%s") problems.
4362 We eliminated a copyright problem on the rpc and ptrace header files
4363 for VxWorks, which was discovered at the last minute during the 4.7
4364 release. You should now be able to build a VxWorks GDB.
4366 You can now interrupt gdb while an attached process is running. This
4367 will cause the attached process to stop, and give control back to GDB.
4369 We fixed problems caused by using too many file descriptors
4370 for reading symbols from object files and libraries. This was
4371 especially a problem for programs that used many (~100) shared
4374 The `step' command now only enters a subroutine if there is line number
4375 information for the subroutine. Otherwise it acts like the `next'
4376 command. Previously, `step' would enter subroutines if there was
4377 any debugging information about the routine. This avoids problems
4378 when using `cc -g1' on MIPS machines.
4380 * Internal improvements
4382 GDB's internal interfaces have been improved to make it easier to support
4383 debugging of multiple languages in the future.
4385 GDB now uses a common structure for symbol information internally.
4386 Minimal symbols (derived from linkage symbols in object files), partial
4387 symbols (from a quick scan of debug information), and full symbols
4388 contain a common subset of information, making it easier to write
4389 shared code that handles any of them.
4391 * New command line options
4393 We now accept --silent as an alias for --quiet.
4397 The memory-mapped-malloc library is now licensed under the GNU Library
4398 General Public License.
4400 *** Changes in GDB-4.7:
4402 * Host/native/target split
4404 GDB has had some major internal surgery to untangle the support for
4405 hosts and remote targets. Now, when you configure GDB for a remote
4406 target, it will no longer load in all of the support for debugging
4407 local programs on the host. When fully completed and tested, this will
4408 ensure that arbitrary host/target combinations are possible.
4410 The primary conceptual shift is to separate the non-portable code in
4411 GDB into three categories. Host specific code is required any time GDB
4412 is compiled on that host, regardless of the target. Target specific
4413 code relates to the peculiarities of the target, but can be compiled on
4414 any host. Native specific code is everything else: it can only be
4415 built when the host and target are the same system. Child process
4416 handling and core file support are two common `native' examples.
4418 GDB's use of /proc for controlling Unix child processes is now cleaner.
4419 It has been split out into a single module under the `target_ops' vector,
4420 plus two native-dependent functions for each system that uses /proc.
4422 * New hosts supported
4424 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4425 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4426 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4428 * New targets supported
4430 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4431 68030 and CPU32 m68030-*-*, m68332-*-*
4433 * New native hosts supported
4435 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4436 (386bsd is not well tested yet)
4437 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4439 * New file formats supported
4441 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4442 supports reading of `a.out.adobe' object files, which are an a.out
4443 format extended with minimal information about multiple sections.
4447 `show copying' is the same as the old `info copying'.
4448 `show warranty' is the same as `info warrantee'.
4449 These were renamed for consistency. The old commands continue to work.
4451 `info handle' is a new alias for `info signals'.
4453 You can now define pre-command hooks, which attach arbitrary command
4454 scripts to any command. The commands in the hook will be executed
4455 prior to the user's command. You can also create a hook which will be
4456 executed whenever the program stops. See gdb.texinfo.
4460 We now deal with Cfront style name mangling, and can even extract type
4461 info from mangled symbols. GDB can automatically figure out which
4462 symbol mangling style your C++ compiler uses.
4464 Calling of methods and virtual functions has been improved as well.
4468 The crash that occured when debugging Sun Ansi-C compiled binaries is
4469 fixed. This was due to mishandling of the extra N_SO stabs output
4472 We also finally got Ultrix 4.2 running in house, and fixed core file
4473 support, with help from a dozen people on the net.
4475 John M. Farrell discovered that the reason that single-stepping was so
4476 slow on all of the Mips based platforms (primarily SGI and DEC) was
4477 that we were trying to demangle and lookup a symbol used for internal
4478 purposes on every instruction that was being stepped through. Changing
4479 the name of that symbol so that it couldn't be mistaken for a C++
4480 mangled symbol sped things up a great deal.
4482 Rich Pixley sped up symbol lookups in general by getting much smarter
4483 about when C++ symbol mangling is necessary. This should make symbol
4484 completion (TAB on the command line) much faster. It's not as fast as
4485 we'd like, but it's significantly faster than gdb-4.6.
4489 A new user controllable variable 'call_scratch_address' can
4490 specify the location of a scratch area to be used when GDB
4491 calls a function in the target. This is necessary because the
4492 usual method of putting the scratch area on the stack does not work
4493 in systems that have separate instruction and data spaces.
4495 We integrated changes to support the 29k UDI (Universal Debugger
4496 Interface), but discovered at the last minute that we didn't have all
4497 of the appropriate copyright paperwork. We are working with AMD to
4498 resolve this, and hope to have it available soon.
4502 We have sped up the remote serial line protocol, especially for targets
4503 with lots of registers. It now supports a new `expedited status' ('T')
4504 message which can be used in place of the existing 'S' status message.
4505 This allows the remote stub to send only the registers that GDB
4506 needs to make a quick decision about single-stepping or conditional
4507 breakpoints, eliminating the need to fetch the entire register set for
4508 each instruction being stepped through.
4510 The GDB remote serial protocol now implements a write-through cache for
4511 registers, only re-reading the registers if the target has run.
4513 There is also a new remote serial stub for SPARC processors. You can
4514 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4515 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4516 processor with a serial port.
4520 Configure.in files have become much easier to read and modify. A new
4521 `table driven' format makes it more obvious what configurations are
4522 supported, and what files each one uses.
4526 There is a new opcodes library which will eventually contain all of the
4527 disassembly routines and opcode tables. At present, it only contains
4528 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4529 disassembler (binutils/objdump) to share these routines.
4531 The libiberty library is now copylefted under the GNU Library General
4532 Public License. This allows more liberal use, and was done so libg++
4533 can use it. This makes no difference to GDB, since the Library License
4534 grants all the rights from the General Public License.
4538 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4539 reference to the stabs symbol info used by the debugger. It is (as far
4540 as we know) the only published document on this fascinating topic. We
4541 encourage you to read it, compare it to the stabs information on your
4542 system, and send improvements on the document in general (to
4543 bug-gdb@prep.ai.mit.edu).
4545 And, of course, many bugs have been fixed.
4548 *** Changes in GDB-4.6:
4550 * Better support for C++ function names
4552 GDB now accepts as input the "demangled form" of C++ overloaded function
4553 names and member function names, and can do command completion on such names
4554 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4555 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4556 Make use of command completion, it is your friend.
4558 GDB also now accepts a variety of C++ mangled symbol formats. They are
4559 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4560 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4561 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4562 for the list of formats.
4564 * G++ symbol mangling problem
4566 Recent versions of gcc have a bug in how they emit debugging information for
4567 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4568 directory) can be applied to gcc to fix the problem. Alternatively, if you
4569 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4570 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4571 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4574 * New 'maintenance' command
4576 All of the commands related to hacking GDB internals have been moved out of
4577 the main command set, and now live behind the 'maintenance' command. This
4578 can also be abbreviated as 'mt'. The following changes were made:
4580 dump-me -> maintenance dump-me
4581 info all-breakpoints -> maintenance info breakpoints
4582 printmsyms -> maintenance print msyms
4583 printobjfiles -> maintenance print objfiles
4584 printpsyms -> maintenance print psymbols
4585 printsyms -> maintenance print symbols
4587 The following commands are new:
4589 maintenance demangle Call internal GDB demangler routine to
4590 demangle a C++ link name and prints the result.
4591 maintenance print type Print a type chain for a given symbol
4593 * Change to .gdbinit file processing
4595 We now read the $HOME/.gdbinit file before processing the argv arguments
4596 (e.g. reading symbol files or core files). This allows global parameters to
4597 be set, which will apply during the symbol reading. The ./.gdbinit is still
4598 read after argv processing.
4600 * New hosts supported
4602 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4604 GNU/Linux support i386-unknown-linux or linux
4606 We are also including code to support the HP/PA running BSD and HPUX. This
4607 is almost guaranteed not to work, as we didn't have time to test or build it
4608 for this release. We are including it so that the more adventurous (or
4609 masochistic) of you can play with it. We also had major problems with the
4610 fact that the compiler that we got from HP doesn't support the -g option.
4613 * New targets supported
4615 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4617 * More smarts about finding #include files
4619 GDB now remembers the compilation directory for all include files, and for
4620 all files from which C is generated (like yacc and lex sources). This
4621 greatly improves GDB's ability to find yacc/lex sources, and include files,
4622 especially if you are debugging your program from a directory different from
4623 the one that contains your sources.
4625 We also fixed a bug which caused difficulty with listing and setting
4626 breakpoints in include files which contain C code. (In the past, you had to
4627 try twice in order to list an include file that you hadn't looked at before.)
4629 * Interesting infernals change
4631 GDB now deals with arbitrary numbers of sections, where the symbols for each
4632 section must be relocated relative to that section's landing place in the
4633 target's address space. This work was needed to support ELF with embedded
4634 stabs used by Solaris-2.0.
4636 * Bug fixes (of course!)
4638 There have been loads of fixes for the following things:
4639 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4640 i960, stabs, DOS(GO32), procfs, etc...
4642 See the ChangeLog for details.
4644 *** Changes in GDB-4.5:
4646 * New machines supported (host and target)
4648 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4650 SGI Irix-4.x mips-sgi-irix4 or iris4
4652 * New malloc package
4654 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4655 Mmalloc is capable of handling mutiple heaps of memory. It is also
4656 capable of saving a heap to a file, and then mapping it back in later.
4657 This can be used to greatly speedup the startup of GDB by using a
4658 pre-parsed symbol table which lives in a mmalloc managed heap. For
4659 more details, please read mmalloc/mmalloc.texi.
4663 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4664 'help info proc' for details.
4666 * MIPS ecoff symbol table format
4668 The code that reads MIPS symbol table format is now supported on all hosts.
4669 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4672 * File name changes for MS-DOS
4674 Many files in the config directories have been renamed to make it easier to
4675 support GDB on MS-DOSe systems (which have very restrictive file name
4676 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4677 environment) is close to working but has some remaining problems. Note
4678 that debugging of DOS programs is not supported, due to limitations
4679 in the ``operating system'', but it can be used to host cross-debugging.
4681 * Cross byte order fixes
4683 Many fixes have been made to support cross debugging of Sparc and MIPS
4684 targets from hosts whose byte order differs.
4686 * New -mapped and -readnow options
4688 If memory-mapped files are available on your system through the 'mmap'
4689 system call, you can use the -mapped option on the `file' or
4690 `symbol-file' commands to cause GDB to write the symbols from your
4691 program into a reusable file. If the program you are debugging is
4692 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4693 Future GDB debugging sessions will notice the presence of this file,
4694 and will quickly map in symbol information from it, rather than reading
4695 the symbol table from the executable program. Using the '-mapped'
4696 option in a GDB `file' or `symbol-file' command has the same effect as
4697 starting GDB with the '-mapped' command-line option.
4699 You can cause GDB to read the entire symbol table immediately by using
4700 the '-readnow' option with any of the commands that load symbol table
4701 information (or on the GDB command line). This makes the command
4702 slower, but makes future operations faster.
4704 The -mapped and -readnow options are typically combined in order to
4705 build a `fred.syms' file that contains complete symbol information.
4706 A simple GDB invocation to do nothing but build a `.syms' file for future
4709 gdb -batch -nx -mapped -readnow programname
4711 The `.syms' file is specific to the host machine on which GDB is run.
4712 It holds an exact image of GDB's internal symbol table. It cannot be
4713 shared across multiple host platforms.
4715 * longjmp() handling
4717 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4718 siglongjmp() without losing control. This feature has not yet been ported to
4719 all systems. It currently works on many 386 platforms, all MIPS-based
4720 platforms (SGI, DECstation, etc), and Sun3/4.
4724 Preliminary work has been put in to support the new Solaris OS from Sun. At
4725 this time, it can control and debug processes, but it is not capable of
4730 As always, many many bug fixes. The major areas were with g++, and mipsread.
4731 People using the MIPS-based platforms should experience fewer mysterious
4732 crashes and trashed symbol tables.
4734 *** Changes in GDB-4.4:
4736 * New machines supported (host and target)
4738 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4740 BSD Reno on Vax vax-dec-bsd
4741 Ultrix on Vax vax-dec-ultrix
4743 * New machines supported (target)
4745 AMD 29000 embedded, using EBMON a29k-none-none
4749 GDB continues to improve its handling of C++. `References' work better.
4750 The demangler has also been improved, and now deals with symbols mangled as
4751 per the Annotated C++ Reference Guide.
4753 GDB also now handles `stabs' symbol information embedded in MIPS
4754 `ecoff' symbol tables. Since the ecoff format was not easily
4755 extensible to handle new languages such as C++, this appeared to be a
4756 good way to put C++ debugging info into MIPS binaries. This option
4757 will be supported in the GNU C compiler, version 2, when it is
4760 * New features for SVR4
4762 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4763 shared libraries. Debugging dynamically linked programs should present
4764 only minor differences from debugging statically linked programs.
4766 The `info proc' command will print out information about any process
4767 on an SVR4 system (including the one you are debugging). At the moment,
4768 it prints the address mappings of the process.
4770 If you bring up GDB on another SVR4 system, please send mail to
4771 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4773 * Better dynamic linking support in SunOS
4775 Reading symbols from shared libraries which contain debugging symbols
4776 now works properly. However, there remain issues such as automatic
4777 skipping of `transfer vector' code during function calls, which
4778 make it harder to debug code in a shared library, than to debug the
4779 same code linked statically.
4783 GDB is now using the latest `getopt' routines from the FSF. This
4784 version accepts the -- prefix for options with long names. GDB will
4785 continue to accept the old forms (-option and +option) as well.
4786 Various single letter abbreviations for options have been explicity
4787 added to the option table so that they won't get overshadowed in the
4788 future by other options that begin with the same letter.
4792 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4793 Many assorted bugs have been handled. Many more remain to be handled.
4794 See the various ChangeLog files (primarily in gdb and bfd) for details.
4797 *** Changes in GDB-4.3:
4799 * New machines supported (host and target)
4801 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4802 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4803 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4805 * Almost SCO Unix support
4807 We had hoped to support:
4808 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4809 (except for core file support), but we discovered very late in the release
4810 that it has problems with process groups that render gdb unusable. Sorry
4811 about that. I encourage people to fix it and post the fixes.
4813 * Preliminary ELF and DWARF support
4815 GDB can read ELF object files on System V Release 4, and can handle
4816 debugging records for C, in DWARF format, in ELF files. This support
4817 is preliminary. If you bring up GDB on another SVR4 system, please
4818 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4823 GDB now uses the latest `readline' library. One user-visible change
4824 is that two tabs will list possible command completions, which previously
4825 required typing M-? (meta-question mark, or ESC ?).
4829 The `stepi' bug that many of you noticed has been squashed.
4830 Many bugs in C++ have been handled. Many more remain to be handled.
4831 See the various ChangeLog files (primarily in gdb and bfd) for details.
4833 * State of the MIPS world (in case you wondered):
4835 GDB can understand the symbol tables emitted by the compilers
4836 supplied by most vendors of MIPS-based machines, including DEC. These
4837 symbol tables are in a format that essentially nobody else uses.
4839 Some versions of gcc come with an assembler post-processor called
4840 mips-tfile. This program is required if you want to do source-level
4841 debugging of gcc-compiled programs. I believe FSF does not ship
4842 mips-tfile with gcc version 1, but it will eventually come with gcc
4845 Debugging of g++ output remains a problem. g++ version 1.xx does not
4846 really support it at all. (If you're lucky, you should be able to get
4847 line numbers and stack traces to work, but no parameters or local
4848 variables.) With some work it should be possible to improve the
4851 When gcc version 2 is released, you will have somewhat better luck.
4852 However, even then you will get confusing results for inheritance and
4855 We will eventually provide full debugging of g++ output on
4856 DECstations. This will probably involve some kind of stabs-in-ecoff
4857 encapulation, but the details have not been worked out yet.
4860 *** Changes in GDB-4.2:
4862 * Improved configuration
4864 Only one copy of `configure' exists now, and it is not self-modifying.
4865 Porting BFD is simpler.
4869 The `step' and `next' commands now only stop at the first instruction
4870 of a source line. This prevents the multiple stops that used to occur
4871 in switch statements, for-loops, etc. `Step' continues to stop if a
4872 function that has debugging information is called within the line.
4876 Lots of small bugs fixed. More remain.
4878 * New host supported (not target)
4880 Intel 386 PC clone running Mach i386-none-mach
4883 *** Changes in GDB-4.1:
4885 * Multiple source language support
4887 GDB now has internal scaffolding to handle several source languages.
4888 It determines the type of each source file from its filename extension,
4889 and will switch expression parsing and number formatting to match the
4890 language of the function in the currently selected stack frame.
4891 You can also specifically set the language to be used, with
4892 `set language c' or `set language modula-2'.
4896 GDB now has preliminary support for the GNU Modula-2 compiler,
4897 currently under development at the State University of New York at
4898 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4899 continue through the fall of 1991 and into 1992.
4901 Other Modula-2 compilers are currently not supported, and attempting to
4902 debug programs compiled with them will likely result in an error as the
4903 symbol table is read. Feel free to work on it, though!
4905 There are hooks in GDB for strict type checking and range checking,
4906 in the `Modula-2 philosophy', but they do not currently work.
4910 GDB can now write to executable and core files (e.g. patch
4911 a variable's value). You must turn this switch on, specify
4912 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4913 by assigning a new value to a variable. Modifications take
4916 * Automatic SunOS shared library reading
4918 When you run your program, GDB automatically determines where its
4919 shared libraries (if any) have been loaded, and reads their symbols.
4920 The `share' command is no longer needed. This also works when
4921 examining core files.
4925 You can specify the number of lines that the `list' command shows.
4928 * New machines supported (host and target)
4930 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4931 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4932 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4934 * New hosts supported (not targets)
4936 IBM RT/PC: romp-ibm-aix or rtpc
4938 * New targets supported (not hosts)
4940 AMD 29000 embedded with COFF a29k-none-coff
4941 AMD 29000 embedded with a.out a29k-none-aout
4942 Ultracomputer remote kernel debug a29k-nyu-kern
4944 * New remote interfaces
4950 *** Changes in GDB-4.0:
4954 Wide output is wrapped at good places to make the output more readable.
4956 Gdb now supports cross-debugging from a host machine of one type to a
4957 target machine of another type. Communication with the target system
4958 is over serial lines. The ``target'' command handles connecting to the
4959 remote system; the ``load'' command will download a program into the
4960 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4961 also supports debugging of realtime processes running under VxWorks,
4962 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4963 stub on the target system.
4965 New CPUs supported include the AMD 29000 and Intel 960.
4967 GDB now reads object files and symbol tables via a ``binary file''
4968 library, which allows a single copy of GDB to debug programs of multiple
4969 object file types such as a.out and coff.
4971 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4972 refcard.dvi and refcard.ps are available to format it).
4975 * Control-Variable user interface simplified
4977 All variables that control the operation of the debugger can be set
4978 by the ``set'' command, and displayed by the ``show'' command.
4980 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4981 ``Show prompt'' produces the response:
4982 Gdb's prompt is new-gdb=>.
4984 What follows are the NEW set commands. The command ``help set'' will
4985 print a complete list of old and new set commands. ``help set FOO''
4986 will give a longer description of the variable FOO. ``show'' will show
4987 all of the variable descriptions and their current settings.
4989 confirm on/off: Enables warning questions for operations that are
4990 hard to recover from, e.g. rerunning the program while
4991 it is already running. Default is ON.
4993 editing on/off: Enables EMACS style command line editing
4994 of input. Previous lines can be recalled with
4995 control-P, the current line can be edited with control-B,
4996 you can search for commands with control-R, etc.
4999 history filename NAME: NAME is where the gdb command history
5000 will be stored. The default is .gdb_history,
5001 or the value of the environment variable
5004 history size N: The size, in commands, of the command history. The
5005 default is 256, or the value of the environment variable
5008 history save on/off: If this value is set to ON, the history file will
5009 be saved after exiting gdb. If set to OFF, the
5010 file will not be saved. The default is OFF.
5012 history expansion on/off: If this value is set to ON, then csh-like
5013 history expansion will be performed on
5014 command line input. The default is OFF.
5016 radix N: Sets the default radix for input and output. It can be set
5017 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5018 in the current radix, so "set radix 10" is always a no-op.
5020 height N: This integer value is the number of lines on a page. Default
5021 is 24, the current `stty rows'' setting, or the ``li#''
5022 setting from the termcap entry matching the environment
5025 width N: This integer value is the number of characters on a line.
5026 Default is 80, the current `stty cols'' setting, or the ``co#''
5027 setting from the termcap entry matching the environment
5030 Note: ``set screensize'' is obsolete. Use ``set height'' and
5031 ``set width'' instead.
5033 print address on/off: Print memory addresses in various command displays,
5034 such as stack traces and structure values. Gdb looks
5035 more ``symbolic'' if you turn this off; it looks more
5036 ``machine level'' with it on. Default is ON.
5038 print array on/off: Prettyprint arrays. New convenient format! Default
5041 print demangle on/off: Print C++ symbols in "source" form if on,
5044 print asm-demangle on/off: Same, for assembler level printouts
5047 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5050 * Support for Epoch Environment.
5052 The epoch environment is a version of Emacs v18 with windowing. One
5053 new command, ``inspect'', is identical to ``print'', except that if you
5054 are running in the epoch environment, the value is printed in its own
5058 * Support for Shared Libraries
5060 GDB can now debug programs and core files that use SunOS shared libraries.
5061 Symbols from a shared library cannot be referenced
5062 before the shared library has been linked with the program (this
5063 happens after you type ``run'' and before the function main() is entered).
5064 At any time after this linking (including when examining core files
5065 from dynamically linked programs), gdb reads the symbols from each
5066 shared library when you type the ``sharedlibrary'' command.
5067 It can be abbreviated ``share''.
5069 sharedlibrary REGEXP: Load shared object library symbols for files
5070 matching a unix regular expression. No argument
5071 indicates to load symbols for all shared libraries.
5073 info sharedlibrary: Status of loaded shared libraries.
5078 A watchpoint stops execution of a program whenever the value of an
5079 expression changes. Checking for this slows down execution
5080 tremendously whenever you are in the scope of the expression, but is
5081 quite useful for catching tough ``bit-spreader'' or pointer misuse
5082 problems. Some machines such as the 386 have hardware for doing this
5083 more quickly, and future versions of gdb will use this hardware.
5085 watch EXP: Set a watchpoint (breakpoint) for an expression.
5087 info watchpoints: Information about your watchpoints.
5089 delete N: Deletes watchpoint number N (same as breakpoints).
5090 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5091 enable N: Re-enables watchpoint number N (same as breakpoints).
5094 * C++ multiple inheritance
5096 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5099 * C++ exception handling
5101 Gdb now supports limited C++ exception handling. Besides the existing
5102 ability to breakpoint on an exception handler, gdb can breakpoint on
5103 the raising of an exception (before the stack is peeled back to the
5106 catch FOO: If there is a FOO exception handler in the dynamic scope,
5107 set a breakpoint to catch exceptions which may be raised there.
5108 Multiple exceptions (``catch foo bar baz'') may be caught.
5110 info catch: Lists all exceptions which may be caught in the
5111 current stack frame.
5114 * Minor command changes
5116 The command ``call func (arg, arg, ...)'' now acts like the print
5117 command, except it does not print or save a value if the function's result
5118 is void. This is similar to dbx usage.
5120 The ``up'' and ``down'' commands now always print the frame they end up
5121 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5122 frames without printing.
5124 * New directory command
5126 'dir' now adds directories to the FRONT of the source search path.
5127 The path starts off empty. Source files that contain debug information
5128 about the directory in which they were compiled can be found even
5129 with an empty path; Sun CC and GCC include this information. If GDB can't
5130 find your source file in the current directory, type "dir .".
5132 * Configuring GDB for compilation
5134 For normal use, type ``./configure host''. See README or gdb.texinfo
5137 GDB now handles cross debugging. If you are remotely debugging between
5138 two different machines, type ``./configure host -target=targ''.
5139 Host is the machine where GDB will run; targ is the machine
5140 where the program that you are debugging will run.