1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
6 * The option "symbol-reloading" has been deleted as it is no longer used.
10 ** GDB commands implemented in Python can now be put in command class
13 ** The "maint set python print-stack on|off" is now deleted.
15 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
16 apply "flag enum"-style pretty-printing to any enum.
18 ** gdb.lookup_symbol can now work when there is no current frame.
20 ** gdb.Symbol now has a 'line' attribute, holding the line number in
21 the source at which the symbol was defined.
23 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
24 method 'value'. The former indicates whether the symbol needs a
25 frame in order to compute its value, and the latter computes the
28 ** A new method 'referenced_value' on gdb.Value objects which can
29 dereference pointer as well as C++ reference values.
31 * GDBserver now supports stdio connections.
32 E.g. (gdb) target remote | ssh myhost gdbserver - hello
34 * The binary "gdbtui" can no longer be built or installed.
35 Use "gdb -tui" instead.
37 * GDB will now print "flag" enums specially. A flag enum is one where
38 all the enumerator values have no bits in common when pairwise
39 "and"ed. When printing a value whose type is a flag enum, GDB will
40 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
41 (gdb) print (enum E) 3
44 * The filename part of a linespec will now match trailing components
45 of a source file name. For example, "break gcc/expr.c:1000" will
46 now set a breakpoint in build/gcc/expr.c, but not
49 * The "info proc" and "generate-core-file" commands will now also
50 work on remote targets connected to GDBserver on Linux.
52 * The command "info catch" has been removed. It has been disabled
55 * The "catch exception" and "catch assert" commands now accept
56 a condition at the end of the command, much like the "break"
57 command does. For instance:
59 (gdb) catch exception Constraint_Error if Barrier = True
61 Previously, it was possible to add a condition to such catchpoints,
62 but it had to be done as a second step, after the catchpoint had been
63 created, using the "condition" command.
65 * The "info static-tracepoint-marker" command will now also work on
66 native Linux targets with in-process agent.
68 * GDB can now set breakpoints on inlined functions.
70 * The .gdb_index section has been updated to include symbols for
71 inlined functions. GDB will ignore older .gdb_index sections by
72 default, which could cause symbol files to be loaded more slowly
73 until their .gdb_index sections can be recreated. The new option
74 --use-deprecated-index-sections will cause GDB to use any older
75 .gdb_index sections it finds. This will restore performance, but
76 the ability to set breakpoints on inlined functions will be lost
77 in symbol files with older .gdb_index sections.
81 ** "catch load" and "catch unload" can be used to stop when a shared
82 library is loaded or unloaded, respectively.
84 ** "enable count" can be used to auto-disable a breakpoint after
87 ** "info vtbl" can be used to show the virtual method tables for
92 Renesas RL78 rl78-*-elf
93 HP OpenVMS ia64 ia64-hp-openvms*
95 * GDBserver supports evaluation of breakpoint conditions. When
96 support is advertised by GDBserver, GDB may be told to send the
97 breakpoint conditions in bytecode form to GDBserver. GDBserver
98 will only report the breakpoint trigger to GDB when its condition
103 set breakpoint condition-evaluation
104 show breakpoint condition-evaluation
105 Controls whether breakpoint conditions are evaluated by GDB ("gdb") or by
106 GDBserver ("target").
107 This option can improve debugger efficiency depending on the speed of the
112 z0/z1 conditional breakpoints extension
114 The z0/z1 breakpoint insertion packets have been extended to carry
115 a list of conditional expressions over to the remote stub depending on the
116 condition evaluation mode. The use of this extension can be controlled
117 via the "set remote conditional-breakpoints-packet" command.
121 Specify the signals which the remote stub may pass to the debugged
122 program without GDB involvement.
124 * New command line options
126 --init-command=FILE, -ix Like --command, -x but execute it
127 before loading inferior.
128 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
129 execute it before loading inferior.
131 *** Changes in GDB 7.4
133 * GDB now handles ambiguous linespecs more consistently; the existing
134 FILE:LINE support has been expanded to other types of linespecs. A
135 breakpoint will now be set on all matching locations in all
136 inferiors, and locations will be added or removed according to
139 * GDB now allows you to skip uninteresting functions and files when
140 stepping with the "skip function" and "skip file" commands.
142 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
143 and "show remote hardware-watchpoint-length-limit". These allows to
144 set or show the maximum length limit (in bytes) of a remote
145 target hardware watchpoint.
147 This allows e.g. to use "unlimited" hardware watchpoints with the
148 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
149 watchpoints are slower than real hardware watchpoints but are
150 significantly faster than gdb software watchpoints.
154 ** The register_pretty_printer function in module gdb.printing now takes
155 an optional `replace' argument. If True, the new printer replaces any
158 ** The "maint set python print-stack on|off" command has been
159 deprecated and will be deleted in GDB 7.5.
160 A new command: "set python print-stack none|full|message" has
161 replaced it. Additionally, the default for "print-stack" is
162 now "message", which just prints the error message without
165 ** A prompt substitution hook (prompt_hook) is now available to the
168 ** A new Python module, gdb.prompt has been added to the GDB Python
169 modules library. This module provides functionality for
170 escape sequences in prompts (used by set/show
171 extended-prompt). These escape sequences are replaced by their
174 ** Python commands and convenience-functions located in
175 'data-directory'/python/gdb/command and
176 'data-directory'/python/gdb/function are now automatically loaded
179 ** Blocks now provide four new attributes. global_block and
180 static_block will return the global and static blocks
181 respectively. is_static and is_global are boolean attributes
182 that indicate if the block is one of those two types.
184 ** Symbols now provide the "type" attribute, the type of the symbol.
186 ** The "gdb.breakpoint" function has been deprecated in favor of
189 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
190 of a function. This class is based on the "finish" command
191 available in the CLI.
193 ** Type objects for struct and union types now allow access to
194 the fields using standard Python dictionary (mapping) methods.
195 For example, "some_type['myfield']" now works, as does
198 ** A new event "gdb.new_objfile" has been added, triggered by loading a
201 ** A new function, "deep_items" has been added to the gdb.types
202 module in the GDB Python modules library. This function returns
203 an iterator over the fields of a struct or union type. Unlike
204 the standard Python "iteritems" method, it will recursively traverse
205 any anonymous fields.
209 ** "*stopped" events can report several new "reason"s, such as
212 ** Breakpoint changes are now notified using new async records, like
213 "=breakpoint-modified".
215 ** New command -ada-task-info.
217 * libthread-db-search-path now supports two special values: $sdir and $pdir.
218 $sdir specifies the default system locations of shared libraries.
219 $pdir specifies the directory where the libpthread used by the application
222 GDB no longer looks in $sdir and $pdir after it has searched the directories
223 mentioned in libthread-db-search-path. If you want to search those
224 directories, they must be specified in libthread-db-search-path.
225 The default value of libthread-db-search-path on GNU/Linux and Solaris
226 systems is now "$sdir:$pdir".
228 $pdir is not supported by gdbserver, it is currently ignored.
229 $sdir is supported by gdbserver.
231 * New configure option --with-iconv-bin.
232 When using the internationalization support like the one in the GNU C
233 library, GDB will invoke the "iconv" program to get a list of supported
234 character sets. If this program lives in a non-standard location, one can
235 use this option to specify where to find it.
237 * When natively debugging programs on PowerPC BookE processors running
238 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
239 watchpoints, which specify a mask in addition to an address to watch.
240 The mask specifies that some bits of an address (the bits which are
241 reset in the mask) should be ignored when matching the address accessed
242 by the inferior against the watchpoint address. See the "PowerPC Embedded"
243 section in the user manual for more details.
245 * The new option --once causes GDBserver to stop listening for connections once
246 the first connection is made. The listening port used by GDBserver will
247 become available after that.
249 * New commands "info macros" and "alias" have been added.
251 * New function parameters suffix @entry specifies value of function parameter
252 at the time the function got called. Entry values are available only since
258 "!" is now an alias of the "shell" command.
259 Note that no space is needed between "!" and SHELL COMMAND.
263 watch EXPRESSION mask MASK_VALUE
264 The watch command now supports the mask argument which allows creation
265 of masked watchpoints, if the current architecture supports this feature.
267 info auto-load-scripts [REGEXP]
268 This command was formerly named "maintenance print section-scripts".
269 It is now generally useful and is no longer a maintenance-only command.
271 info macro [-all] [--] MACRO
272 The info macro command has new options `-all' and `--'. The first for
273 printing all definitions of a macro. The second for explicitly specifying
274 the end of arguments and the beginning of the macro name in case the macro
275 name starts with a hyphen.
277 collect[/s] EXPRESSIONS
278 The tracepoint collect command now takes an optional modifier "/s"
279 that directs it to dereference pointer-to-character types and
280 collect the bytes of memory up to a zero byte. The behavior is
281 similar to what you see when you use the regular print command on a
282 string. An optional integer following the "/s" sets a bound on the
283 number of bytes that will be collected.
286 The trace start command now interprets any supplied arguments as a
287 note to be recorded with the trace run, with an effect similar to
288 setting the variable trace-notes.
291 The trace stop command now interprets any arguments as a note to be
292 mentioned along with the tstatus report that the trace was stopped
293 with a command. The effect is similar to setting the variable
296 * Tracepoints can now be enabled and disabled at any time after a trace
297 experiment has been started using the standard "enable" and "disable"
298 commands. It is now possible to start a trace experiment with no enabled
299 tracepoints; GDB will display a warning, but will allow the experiment to
300 begin, assuming that tracepoints will be enabled as needed while the trace
303 * Fast tracepoints on 32-bit x86-architectures can now be placed at
304 locations with 4-byte instructions, when they were previously
305 limited to locations with instructions of 5 bytes or longer.
311 Set the GDB prompt, and allow escape sequences to be inserted to
312 display miscellaneous information (see 'help set extended-prompt'
313 for the list of sequences). This prompt (and any information
314 accessed through the escape sequences) is updated every time the
317 set print entry-values (both|compact|default|if-needed|no|only|preferred)
318 show print entry-values
319 Set printing of frame argument values at function entry. In some cases
320 GDB can determine the value of function argument which was passed by the
321 function caller, even if the value was modified inside the called function.
323 set debug entry-values
324 show debug entry-values
325 Control display of debugging info for determining frame argument values at
326 function entry and virtual tail call frames.
328 set basenames-may-differ
329 show basenames-may-differ
330 Set whether a source file may have multiple base names.
331 (A "base name" is the name of a file with the directory part removed.
332 Example: The base name of "/home/user/hello.c" is "hello.c".)
333 If set, GDB will canonicalize file names (e.g., expand symlinks)
334 before comparing them. Canonicalization is an expensive operation,
335 but it allows the same file be known by more than one base name.
336 If not set (the default), all source files are assumed to have just
337 one base name, and gdb will do file name comparisons more efficiently.
343 Set a user name and notes for the current and any future trace runs.
344 This is useful for long-running and/or disconnected traces, to
345 inform others (or yourself) as to who is running the trace, supply
346 contact information, or otherwise explain what is going on.
349 show trace-stop-notes
350 Set a note attached to the trace run, that is displayed when the
351 trace has been stopped by a tstop command. This is useful for
352 instance as an explanation, if you are stopping a trace run that was
353 started by someone else.
359 Dynamically enable a tracepoint in a started trace experiment.
363 Dynamically disable a tracepoint in a started trace experiment.
367 Set the user and notes of the trace run.
371 Query the current status of a tracepoint.
375 Query the minimum length of instruction at which a fast tracepoint may
378 * Dcache size (number of lines) and line-size are now runtime-configurable
379 via "set dcache line" and "set dcache line-size" commands.
383 Texas Instruments TMS320C6x tic6x-*-*
387 Renesas RL78 rl78-*-elf
389 *** Changes in GDB 7.3.1
391 * The build failure for NetBSD and OpenBSD targets have now been fixed.
393 *** Changes in GDB 7.3
395 * GDB has a new command: "thread find [REGEXP]".
396 It finds the thread id whose name, target id, or thread extra info
397 matches the given regular expression.
399 * The "catch syscall" command now works on mips*-linux* targets.
401 * The -data-disassemble MI command now supports modes 2 and 3 for
402 dumping the instruction opcodes.
404 * New command line options
406 -data-directory DIR Specify DIR as the "data-directory".
407 This is mostly for testing purposes.
409 * The "maint set python auto-load on|off" command has been renamed to
410 "set auto-load-scripts on|off".
412 * GDB has a new command: "set directories".
413 It is like the "dir" command except that it replaces the
414 source path list instead of augmenting it.
416 * GDB now understands thread names.
418 On GNU/Linux, "info threads" will display the thread name as set by
419 prctl or pthread_setname_np.
421 There is also a new command, "thread name", which can be used to
422 assign a name internally for GDB to display.
425 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
426 has been integrated into GDB.
430 ** The function gdb.Write now accepts an optional keyword 'stream'.
431 This keyword, when provided, will direct the output to either
432 stdout, stderr, or GDB's logging output.
434 ** Parameters can now be be sub-classed in Python, and in particular
435 you may implement the get_set_doc and get_show_doc functions.
436 This improves how Parameter set/show documentation is processed
437 and allows for more dynamic content.
439 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
440 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
441 have an is_valid method.
443 ** Breakpoints can now be sub-classed in Python, and in particular
444 you may implement a 'stop' function that is executed each time
445 the inferior reaches that breakpoint.
447 ** New function gdb.lookup_global_symbol looks up a global symbol.
449 ** GDB values in Python are now callable if the value represents a
450 function. For example, if 'some_value' represents a function that
451 takes two integer parameters and returns a value, you can call
452 that function like so:
454 result = some_value (10,20)
456 ** Module gdb.types has been added.
457 It contains a collection of utilities for working with gdb.Types objects:
458 get_basic_type, has_field, make_enum_dict.
460 ** Module gdb.printing has been added.
461 It contains utilities for writing and registering pretty-printers.
462 New classes: PrettyPrinter, SubPrettyPrinter,
463 RegexpCollectionPrettyPrinter.
464 New function: register_pretty_printer.
466 ** New commands "info pretty-printers", "enable pretty-printer" and
467 "disable pretty-printer" have been added.
469 ** gdb.parameter("directories") is now available.
471 ** New function gdb.newest_frame returns the newest frame in the
474 ** The gdb.InferiorThread class has a new "name" attribute. This
475 holds the thread's name.
477 ** Python Support for Inferior events.
478 Python scripts can add observers to be notified of events
479 occurring in the process being debugged.
480 The following events are currently supported:
481 - gdb.events.cont Continue event.
482 - gdb.events.exited Inferior exited event.
483 - gdb.events.stop Signal received, and Breakpoint hit events.
487 ** GDB now puts template parameters in scope when debugging in an
488 instantiation. For example, if you have:
490 template<int X> int func (void) { return X; }
492 then if you step into func<5>, "print X" will show "5". This
493 feature requires proper debuginfo support from the compiler; it
494 was added to GCC 4.5.
496 ** The motion commands "next", "finish", "until", and "advance" now
497 work better when exceptions are thrown. In particular, GDB will
498 no longer lose control of the inferior; instead, the GDB will
499 stop the inferior at the point at which the exception is caught.
500 This functionality requires a change in the exception handling
501 code that was introduced in GCC 4.5.
503 * GDB now follows GCC's rules on accessing volatile objects when
504 reading or writing target state during expression evaluation.
505 One notable difference to prior behavior is that "print x = 0"
506 no longer generates a read of x; the value of the assignment is
507 now always taken directly from the value being assigned.
509 * GDB now has some support for using labels in the program's source in
510 linespecs. For instance, you can use "advance label" to continue
511 execution to a label.
513 * GDB now has support for reading and writing a new .gdb_index
514 section. This section holds a fast index of DWARF debugging
515 information and can be used to greatly speed up GDB startup and
516 operation. See the documentation for `save gdb-index' for details.
518 * The "watch" command now accepts an optional "-location" argument.
519 When used, this causes GDB to watch the memory referred to by the
520 expression. Such a watchpoint is never deleted due to it going out
523 * GDB now supports thread debugging of core dumps on GNU/Linux.
525 GDB now activates thread debugging using the libthread_db library
526 when debugging GNU/Linux core dumps, similarly to when debugging
527 live processes. As a result, when debugging a core dump file, GDB
528 is now able to display pthread_t ids of threads. For example, "info
529 threads" shows the same output as when debugging the process when it
530 was live. In earlier releases, you'd see something like this:
533 * 1 LWP 6780 main () at main.c:10
535 While now you see this:
538 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
540 It is also now possible to inspect TLS variables when debugging core
543 When debugging a core dump generated on a machine other than the one
544 used to run GDB, you may need to point GDB at the correct
545 libthread_db library with the "set libthread-db-search-path"
546 command. See the user manual for more details on this command.
548 * When natively debugging programs on PowerPC BookE processors running
549 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
550 which stop execution of the inferior whenever it executes an instruction
551 at any address within the specified range. See the "PowerPC Embedded"
552 section in the user manual for more details.
554 * New features in the GDB remote stub, GDBserver
556 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
557 and i686 LynxOS (version 5.x).
559 ** GDBserver is now supported on Blackfin Linux.
561 * New native configurations
563 ia64 HP-UX ia64-*-hpux*
567 Analog Devices, Inc. Blackfin Processor bfin-*
569 * Ada task switching is now supported on sparc-elf targets when
570 debugging a program using the Ravenscar Profile. For more information,
571 see the "Tasking Support when using the Ravenscar Profile" section
572 in the GDB user manual.
574 * Guile support was removed.
576 * New features in the GNU simulator
578 ** The --map-info flag lists all known core mappings.
580 ** CFI flashes may be simulated via the "cfi" device.
582 *** Changes in GDB 7.2
584 * Shared library support for remote targets by default
586 When GDB is configured for a generic, non-OS specific target, like
587 for example, --target=arm-eabi or one of the many *-*-elf targets,
588 GDB now queries remote stubs for loaded shared libraries using the
589 `qXfer:libraries:read' packet. Previously, shared library support
590 was always disabled for such configurations.
594 ** Argument Dependent Lookup (ADL)
596 In C++ ADL lookup directs function search to the namespaces of its
597 arguments even if the namespace has not been imported.
607 Here the compiler will search for `foo' in the namespace of 'b'
608 and find A::foo. GDB now supports this. This construct is commonly
609 used in the Standard Template Library for operators.
611 ** Improved User Defined Operator Support
613 In addition to member operators, GDB now supports lookup of operators
614 defined in a namespace and imported with a `using' directive, operators
615 defined in the global scope, operators imported implicitly from an
616 anonymous namespace, and the ADL operators mentioned in the previous
618 GDB now also supports proper overload resolution for all the previously
619 mentioned flavors of operators.
621 ** static const class members
623 Printing of static const class members that are initialized in the
624 class definition has been fixed.
626 * Windows Thread Information Block access.
628 On Windows targets, GDB now supports displaying the Windows Thread
629 Information Block (TIB) structure. This structure is visible either
630 by using the new command `info w32 thread-information-block' or, by
631 dereferencing the new convenience variable named `$_tlb', a
632 thread-specific pointer to the TIB. This feature is also supported
633 when remote debugging using GDBserver.
637 Static tracepoints are calls in the user program into a tracing
638 library. One such library is a port of the LTTng kernel tracer to
639 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
640 When debugging with GDBserver, GDB now supports combining the GDB
641 tracepoint machinery with such libraries. For example: the user can
642 use GDB to probe a static tracepoint marker (a call from the user
643 program into the tracing library) with the new "strace" command (see
644 "New commands" below). This creates a "static tracepoint" in the
645 breakpoint list, that can be manipulated with the same feature set
646 as fast and regular tracepoints. E.g., collect registers, local and
647 global variables, collect trace state variables, and define
648 tracepoint conditions. In addition, the user can collect extra
649 static tracepoint marker specific data, by collecting the new
650 $_sdata internal variable. When analyzing the trace buffer, you can
651 inspect $_sdata like any other variable available to GDB. For more
652 information, see the "Tracepoints" chapter in GDB user manual. New
653 remote packets have been defined to support static tracepoints, see
654 the "New remote packets" section below.
656 * Better reconstruction of tracepoints after disconnected tracing
658 GDB will attempt to download the original source form of tracepoint
659 definitions when starting a trace run, and then will upload these
660 upon reconnection to the target, resulting in a more accurate
661 reconstruction of the tracepoints that are in use on the target.
665 You can now exercise direct control over the ways that GDB can
666 affect your program. For instance, you can disallow the setting of
667 breakpoints, so that the program can run continuously (assuming
668 non-stop mode). In addition, the "observer" variable is available
669 to switch all of the different controls; in observer mode, GDB
670 cannot affect the target's behavior at all, which is useful for
671 tasks like diagnosing live systems in the field.
673 * The new convenience variable $_thread holds the number of the
680 Return the address of the Windows Thread Information Block of a given thread.
684 In response to several of the tracepoint packets, the target may now
685 also respond with a number of intermediate `qRelocInsn' request
686 packets before the final result packet, to have GDB handle
687 relocating an instruction to execute at a different address. This
688 is particularly useful for stubs that support fast tracepoints. GDB
689 reports support for this feature in the qSupported packet.
693 List static tracepoint markers in the target program.
697 List static tracepoint markers at a given address in the target
700 qXfer:statictrace:read
702 Read the static trace data collected (by a `collect $_sdata'
703 tracepoint action). The remote stub reports support for this packet
704 to gdb's qSupported query.
708 Send the current settings of GDB's permission flags.
712 Send part of the source (textual) form of a tracepoint definition,
713 which includes location, conditional, and action list.
715 * The source command now accepts a -s option to force searching for the
716 script in the source search path even if the script name specifies
719 * New features in the GDB remote stub, GDBserver
721 - GDBserver now support tracepoints (including fast tracepoints, and
722 static tracepoints). The feature is currently supported by the
723 i386-linux and amd64-linux builds. See the "Tracepoints support
724 in gdbserver" section in the manual for more information.
726 GDBserver JIT compiles the tracepoint's conditional agent
727 expression bytecode into native code whenever possible for low
728 overhead dynamic tracepoints conditionals. For such tracepoints,
729 an expression that examines program state is evaluated when the
730 tracepoint is reached, in order to determine whether to capture
731 trace data. If the condition is simple and false, processing the
732 tracepoint finishes very quickly and no data is gathered.
734 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
735 for static tracepoints support.
737 - GDBserver now supports x86_64 Windows 64-bit debugging.
739 * GDB now sends xmlRegisters= in qSupported packet to indicate that
740 it understands register description.
742 * The --batch flag now disables pagination and queries.
744 * X86 general purpose registers
746 GDB now supports reading/writing byte, word and double-word x86
747 general purpose registers directly. This means you can use, say,
748 $ah or $ax to refer, respectively, to the byte register AH and
749 16-bit word register AX that are actually portions of the 32-bit
750 register EAX or 64-bit register RAX.
752 * The `commands' command now accepts a range of breakpoints to modify.
753 A plain `commands' following a command that creates multiple
754 breakpoints affects all the breakpoints set by that command. This
755 applies to breakpoints set by `rbreak', and also applies when a
756 single `break' command creates multiple breakpoints (e.g.,
757 breakpoints on overloaded c++ functions).
759 * The `rbreak' command now accepts a filename specification as part of
760 its argument, limiting the functions selected by the regex to those
761 in the specified file.
763 * Support for remote debugging Windows and SymbianOS shared libraries
764 from Unix hosts has been improved. Non Windows GDB builds now can
765 understand target reported file names that follow MS-DOS based file
766 system semantics, such as file names that include drive letters and
767 use the backslash character as directory separator. This makes it
768 possible to transparently use the "set sysroot" and "set
769 solib-search-path" on Unix hosts to point as host copies of the
770 target's shared libraries. See the new command "set
771 target-file-system-kind" described below, and the "Commands to
772 specify files" section in the user manual for more information.
776 eval template, expressions...
777 Convert the values of one or more expressions under the control
778 of the string template to a command line, and call it.
780 set target-file-system-kind unix|dos-based|auto
781 show target-file-system-kind
782 Set or show the assumed file system kind for target reported file
785 save breakpoints <filename>
786 Save all current breakpoint definitions to a file suitable for use
787 in a later debugging session. To read the saved breakpoint
788 definitions, use the `source' command.
790 `save tracepoints' is a new alias for `save-tracepoints'. The latter
793 info static-tracepoint-markers
794 Display information about static tracepoint markers in the target.
796 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
797 Define a static tracepoint by probing a marker at the given
798 function, line, address, or marker ID.
802 Enable and disable observer mode.
804 set may-write-registers on|off
805 set may-write-memory on|off
806 set may-insert-breakpoints on|off
807 set may-insert-tracepoints on|off
808 set may-insert-fast-tracepoints on|off
809 set may-interrupt on|off
810 Set individual permissions for GDB effects on the target. Note that
811 some of these settings can have undesirable or surprising
812 consequences, particularly when changed in the middle of a session.
813 For instance, disabling the writing of memory can prevent
814 breakpoints from being inserted, cause single-stepping to fail, or
815 even crash your program, if you disable after breakpoints have been
816 inserted. However, GDB should not crash.
818 set record memory-query on|off
819 show record memory-query
820 Control whether to stop the inferior if memory changes caused
821 by an instruction cannot be recorded.
826 The disassemble command now supports "start,+length" form of two arguments.
830 ** GDB now provides a new directory location, called the python directory,
831 where Python scripts written for GDB can be installed. The location
832 of that directory is <data-directory>/python, where <data-directory>
833 is the GDB data directory. For more details, see section `Scripting
834 GDB using Python' in the manual.
836 ** The GDB Python API now has access to breakpoints, symbols, symbol
837 tables, program spaces, inferiors, threads and frame's code blocks.
838 Additionally, GDB Parameters can now be created from the API, and
839 manipulated via set/show in the CLI.
841 ** New functions gdb.target_charset, gdb.target_wide_charset,
842 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
844 ** New exception gdb.GdbError.
846 ** Pretty-printers are now also looked up in the current program space.
848 ** Pretty-printers can now be individually enabled and disabled.
850 ** GDB now looks for names of Python scripts to auto-load in a
851 special section named `.debug_gdb_scripts', in addition to looking
852 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
854 * Tracepoint actions were unified with breakpoint commands. In particular,
855 there are no longer differences in "info break" output for breakpoints and
856 tracepoints and the "commands" command can be used for both tracepoints and
861 ARM Symbian arm*-*-symbianelf*
863 * D language support.
864 GDB now supports debugging programs written in the D programming
867 * GDB now supports the extended ptrace interface for PowerPC which is
868 available since Linux kernel version 2.6.34. This automatically enables
869 any hardware breakpoints and additional hardware watchpoints available in
870 the processor. The old ptrace interface exposes just one hardware
871 watchpoint and no hardware breakpoints.
873 * GDB is now able to use the Data Value Compare (DVC) register available on
874 embedded PowerPC processors to implement in hardware simple watchpoint
875 conditions of the form:
877 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
879 This works in native GDB running on Linux kernels with the extended ptrace
880 interface mentioned above.
882 *** Changes in GDB 7.1
888 GDB now supports importing of namespaces in C++. This enables the
889 user to inspect variables from imported namespaces. Support for
890 namepace aliasing has also been added. So, if a namespace is
891 aliased in the current scope (e.g. namepace C=A; ) the user can
892 print variables using the alias (e.g. (gdb) print C::x).
896 All known bugs relating to the printing of virtual base class were
897 fixed. It is now possible to call overloaded static methods using a
902 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
903 and reinterpret_cast<> are now handled by the C++ expression parser.
907 Xilinx MicroBlaze microblaze-*-*
912 Xilinx MicroBlaze microblaze
915 * Multi-program debugging.
917 GDB now has support for multi-program (a.k.a. multi-executable or
918 multi-exec) debugging. This allows for debugging multiple inferiors
919 simultaneously each running a different program under the same GDB
920 session. See "Debugging Multiple Inferiors and Programs" in the
921 manual for more information. This implied some user visible changes
922 in the multi-inferior support. For example, "info inferiors" now
923 lists inferiors that are not running yet or that have exited
924 already. See also "New commands" and "New options" below.
926 * New tracing features
928 GDB's tracepoint facility now includes several new features:
930 ** Trace state variables
932 GDB tracepoints now include support for trace state variables, which
933 are variables managed by the target agent during a tracing
934 experiment. They are useful for tracepoints that trigger each
935 other, so for instance one tracepoint can count hits in a variable,
936 and then a second tracepoint has a condition that is true when the
937 count reaches a particular value. Trace state variables share the
938 $-syntax of GDB convenience variables, and can appear in both
939 tracepoint actions and condition expressions. Use the "tvariable"
940 command to create, and "info tvariables" to view; see "Trace State
941 Variables" in the manual for more detail.
945 GDB now includes an option for defining fast tracepoints, which
946 targets may implement more efficiently, such as by installing a jump
947 into the target agent rather than a trap instruction. The resulting
948 speedup can be by two orders of magnitude or more, although the
949 tradeoff is that some program locations on some target architectures
950 might not allow fast tracepoint installation, for instance if the
951 instruction to be replaced is shorter than the jump. To request a
952 fast tracepoint, use the "ftrace" command, with syntax identical to
953 the regular trace command.
955 ** Disconnected tracing
957 It is now possible to detach GDB from the target while it is running
958 a trace experiment, then reconnect later to see how the experiment
959 is going. In addition, a new variable disconnected-tracing lets you
960 tell the target agent whether to continue running a trace if the
961 connection is lost unexpectedly.
965 GDB now has the ability to save the trace buffer into a file, and
966 then use that file as a target, similarly to you can do with
967 corefiles. You can select trace frames, print data that was
968 collected in them, and use tstatus to display the state of the
969 tracing run at the moment that it was saved. To create a trace
970 file, use "tsave <filename>", and to use it, do "target tfile
973 ** Circular trace buffer
975 You can ask the target agent to handle the trace buffer as a
976 circular buffer, discarding the oldest trace frames to make room for
977 newer ones, by setting circular-trace-buffer to on. This feature may
978 not be available for all target agents.
983 The disassemble command, when invoked with two arguments, now requires
984 the arguments to be comma-separated.
987 The info variables command now displays variable definitions. Files
988 which only declare a variable are not shown.
991 The source command is now capable of sourcing Python scripts.
992 This feature is dependent on the debugger being build with Python
995 Related to this enhancement is also the introduction of a new command
996 "set script-extension" (see below).
998 * New commands (for set/show, see "New options" below)
1000 record save [<FILENAME>]
1001 Save a file (in core file format) containing the process record
1002 execution log for replay debugging at a later time.
1004 record restore <FILENAME>
1005 Restore the process record execution log that was saved at an
1006 earlier time, for replay debugging.
1008 add-inferior [-copies <N>] [-exec <FILENAME>]
1011 clone-inferior [-copies <N>] [ID]
1012 Make a new inferior ready to execute the same program another
1013 inferior has loaded.
1018 maint info program-spaces
1019 List the program spaces loaded into GDB.
1021 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1022 show remote interrupt-sequence
1023 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1024 as the sequence to the remote target in order to interrupt the execution.
1025 Ctrl-C is a default. Some system prefers BREAK which is high level of
1026 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1027 Magic SysRq g. It is BREAK signal and character 'g'.
1029 set remote interrupt-on-connect [on | off]
1030 show remote interrupt-on-connect
1031 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1032 remote target when gdb connects to it. This is needed when you debug
1035 set remotebreak [on | off]
1037 Deprecated. Use "set/show remote interrupt-sequence" instead.
1039 tvariable $NAME [ = EXP ]
1040 Create or modify a trace state variable.
1043 List trace state variables and their values.
1045 delete tvariable $NAME ...
1046 Delete one or more trace state variables.
1049 Evaluate the given expressions without collecting anything into the
1050 trace buffer. (Valid in tracepoint actions only.)
1052 ftrace FN / FILE:LINE / *ADDR
1053 Define a fast tracepoint at the given function, line, or address.
1055 * New expression syntax
1057 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1058 GDB now parses 0b101010 identically with 42.
1062 set follow-exec-mode new|same
1063 show follow-exec-mode
1064 Control whether GDB reuses the same inferior across an exec call or
1065 creates a new one. This is useful to be able to restart the old
1066 executable after the inferior having done an exec call.
1068 set default-collect EXPR, ...
1069 show default-collect
1070 Define a list of expressions to be collected at each tracepoint.
1071 This is a useful way to ensure essential items are not overlooked,
1072 such as registers or a critical global variable.
1074 set disconnected-tracing
1075 show disconnected-tracing
1076 If set to 1, the target is instructed to continue tracing if it
1077 loses its connection to GDB. If 0, the target is to stop tracing
1080 set circular-trace-buffer
1081 show circular-trace-buffer
1082 If set to on, the target is instructed to use a circular trace buffer
1083 and discard the oldest trace frames instead of stopping the trace due
1084 to a full trace buffer. If set to off, the trace stops when the buffer
1085 fills up. Some targets may not support this.
1087 set script-extension off|soft|strict
1088 show script-extension
1089 If set to "off", the debugger does not perform any script language
1090 recognition, and all sourced files are assumed to be GDB scripts.
1091 If set to "soft" (the default), files are sourced according to
1092 filename extension, falling back to GDB scripts if the first
1094 If set to "strict", files are sourced according to filename extension.
1096 set ada trust-PAD-over-XVS on|off
1097 show ada trust-PAD-over-XVS
1098 If off, activate a workaround against a bug in the debugging information
1099 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1100 the GCC sources for more information about the GNAT encoding and
1101 PAD types in particular). It is always safe to set this option to
1102 off, but this introduces a slight performance penalty. The default
1105 * Python API Improvements
1107 ** GDB provides the new class gdb.LazyString. This is useful in
1108 some pretty-printing cases. The new method gdb.Value.lazy_string
1109 provides a simple way to create objects of this type.
1111 ** The fields returned by gdb.Type.fields now have an
1112 `is_base_class' attribute.
1114 ** The new method gdb.Type.range returns the range of an array type.
1116 ** The new method gdb.parse_and_eval can be used to parse and
1117 evaluate an expression.
1119 * New remote packets
1122 Define a trace state variable.
1125 Get the current value of a trace state variable.
1128 Set desired tracing behavior upon disconnection.
1131 Set the trace buffer to be linear or circular.
1134 Get data about the tracepoints currently in use.
1138 Process record now works correctly with hardware watchpoints.
1140 Multiple bug fixes have been made to the mips-irix port, making it
1141 much more reliable. In particular:
1142 - Debugging threaded applications is now possible again. Previously,
1143 GDB would hang while starting the program, or while waiting for
1144 the program to stop at a breakpoint.
1145 - Attaching to a running process no longer hangs.
1146 - An error occurring while loading a core file has been fixed.
1147 - Changing the value of the PC register now works again. This fixes
1148 problems observed when using the "jump" command, or when calling
1149 a function from GDB, or even when assigning a new value to $pc.
1150 - With the "finish" and "return" commands, the return value for functions
1151 returning a small array is now correctly printed.
1152 - It is now possible to break on shared library code which gets executed
1153 during a shared library init phase (code executed while executing
1154 their .init section). Previously, the breakpoint would have no effect.
1155 - GDB is now able to backtrace through the signal handler for
1156 non-threaded programs.
1158 PIE (Position Independent Executable) programs debugging is now supported.
1159 This includes debugging execution of PIC (Position Independent Code) shared
1160 libraries although for that, it should be possible to run such libraries as an
1163 *** Changes in GDB 7.0
1165 * GDB now has an interface for JIT compilation. Applications that
1166 dynamically generate code can create symbol files in memory and register
1167 them with GDB. For users, the feature should work transparently, and
1168 for JIT developers, the interface is documented in the GDB manual in the
1169 "JIT Compilation Interface" chapter.
1171 * Tracepoints may now be conditional. The syntax is as for
1172 breakpoints; either an "if" clause appended to the "trace" command,
1173 or the "condition" command is available. GDB sends the condition to
1174 the target for evaluation using the same bytecode format as is used
1175 for tracepoint actions.
1177 * The disassemble command now supports: an optional /r modifier, print the
1178 raw instructions in hex as well as in symbolic form, and an optional /m
1179 modifier to print mixed source+assembly.
1181 * Process record and replay
1183 In a architecture environment that supports ``process record and
1184 replay'', ``process record and replay'' target can record a log of
1185 the process execution, and replay it with both forward and reverse
1188 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1189 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1190 set execution-direction {forward|reverse}, for targets that support
1193 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1194 feature is available with a native GDB running on kernel version
1197 * GDB now has support for multi-byte and wide character sets on the
1198 target. Strings whose character type is wchar_t, char16_t, or
1199 char32_t are now correctly printed. GDB supports wide- and unicode-
1200 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1201 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1202 `printf'. This feature requires iconv to work properly; if your
1203 system does not have a working iconv, GDB can use GNU libiconv. See
1204 the installation instructions for more information.
1206 * GDB now supports automatic retrieval of shared library files from
1207 remote targets. To use this feature, specify a system root that begins
1208 with the `remote:' prefix, either via the `set sysroot' command or via
1209 the `--with-sysroot' configure-time option.
1211 * "info sharedlibrary" now takes an optional regex of libraries to show,
1212 and it now reports if a shared library has no debugging information.
1214 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1215 now complete on file names.
1217 * When completing in expressions, gdb will attempt to limit
1218 completions to allowable structure or union fields, where appropriate.
1219 For instance, consider:
1221 # struct example { int f1; double f2; };
1222 # struct example variable;
1225 If the user types TAB at the end of this command line, the available
1226 completions will be "f1" and "f2".
1228 * Inlined functions are now supported. They show up in backtraces, and
1229 the "step", "next", and "finish" commands handle them automatically.
1231 * GDB now supports the token-splicing (##) and stringification (#)
1232 operators when expanding macros. It also supports variable-arity
1235 * GDB now supports inspecting extra signal information, exported by
1236 the new $_siginfo convenience variable. The feature is currently
1237 implemented on linux ARM, i386 and amd64.
1239 * GDB can now display the VFP floating point registers and NEON vector
1240 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1241 can provide these registers (requires Linux 2.6.30 or later). Remote
1242 and simulator targets may also provide them.
1244 * New remote packets
1247 Search memory for a sequence of bytes.
1250 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1251 operation over reliable transport links. Use of this packet is
1252 controlled by the `set remote noack-packet' command.
1255 Kill the process with the specified process ID. Use this in preference
1256 to `k' when multiprocess protocol extensions are supported.
1259 Obtains additional operating system information
1263 Read or write additional signal information.
1265 * Removed remote protocol undocumented extension
1267 An undocumented extension to the remote protocol's `S' stop reply
1268 packet that permited the stub to pass a process id was removed.
1269 Remote servers should use the `T' stop reply packet instead.
1271 * GDB now supports multiple function calling conventions according to the
1272 DWARF-2 DW_AT_calling_convention function attribute.
1274 * The SH target utilizes the aforementioned change to distinguish between gcc
1275 and Renesas calling convention. It also adds the new CLI commands
1276 `set/show sh calling-convention'.
1278 * GDB can now read compressed debug sections, as produced by GNU gold
1279 with the --compress-debug-sections=zlib flag.
1281 * 64-bit core files are now supported on AIX.
1283 * Thread switching is now supported on Tru64.
1285 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1286 which will be allocated using malloc later in program execution.
1288 * The qXfer:libraries:read remote procotol packet now allows passing a
1289 list of section offsets.
1291 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1292 conditions handling signals delivered during attach or thread creation
1293 have also been fixed.
1295 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1296 From the user's standpoint, all unqualified instances of True and False
1297 are treated as the standard definitions, regardless of context.
1299 * GDB now parses C++ symbol and type names more flexibly. For
1302 template<typename T> class C { };
1305 GDB will now correctly handle all of:
1307 ptype C<char const *>
1308 ptype C<char const*>
1309 ptype C<const char *>
1310 ptype C<const char*>
1312 * New features in the GDB remote stub, gdbserver
1314 - The "--wrapper" command-line argument tells gdbserver to use a
1315 wrapper program to launch programs for debugging.
1317 - On PowerPC and S/390 targets, it is now possible to use a single
1318 gdbserver executable to debug both 32-bit and 64-bit programs.
1319 (This requires gdbserver itself to be built as a 64-bit executable.)
1321 - gdbserver uses the new noack protocol mode for TCP connections to
1322 reduce communications latency, if also supported and enabled in GDB.
1324 - Support for the sparc64-linux-gnu target is now included in
1327 - The amd64-linux build of gdbserver now supports debugging both
1328 32-bit and 64-bit programs.
1330 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1331 now support hardware watchpoints, and will use them automatically
1336 GDB now has support for scripting using Python. Whether this is
1337 available is determined at configure time.
1339 New GDB commands can now be written in Python.
1341 * Ada tasking support
1343 Ada tasks can now be inspected in GDB. The following commands have
1347 Print the list of Ada tasks.
1349 Print detailed information about task number N.
1351 Print the task number of the current task.
1353 Switch the context of debugging to task number N.
1355 * Support for user-defined prefixed commands. The "define" command can
1356 add new commands to existing prefixes, e.g. "target".
1358 * Multi-inferior, multi-process debugging.
1360 GDB now has generalized support for multi-inferior debugging. See
1361 "Debugging Multiple Inferiors" in the manual for more information.
1362 Although availability still depends on target support, the command
1363 set is more uniform now. The GNU/Linux specific multi-forks support
1364 has been migrated to this new framework. This implied some user
1365 visible changes; see "New commands" and also "Removed commands"
1368 * Target descriptions can now describe the target OS ABI. See the
1369 "Target Description Format" section in the user manual for more
1372 * Target descriptions can now describe "compatible" architectures
1373 to indicate that the target can execute applications for a different
1374 architecture in addition to those for the main target architecture.
1375 See the "Target Description Format" section in the user manual for
1378 * Multi-architecture debugging.
1380 GDB now includes general supports for debugging applications on
1381 hybrid systems that use more than one single processor architecture
1382 at the same time. Each such hybrid architecture still requires
1383 specific support to be added. The only hybrid architecture supported
1384 in this version of GDB is the Cell Broadband Engine.
1386 * GDB now supports integrated debugging of Cell/B.E. applications that
1387 use both the PPU and SPU architectures. To enable support for hybrid
1388 Cell/B.E. debugging, you need to configure GDB to support both the
1389 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1390 --enable-targets configure option.
1392 * Non-stop mode debugging.
1394 For some targets, GDB now supports an optional mode of operation in
1395 which you can examine stopped threads while other threads continue
1396 to execute freely. This is referred to as non-stop mode, with the
1397 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1398 section in the user manual for more information.
1400 To be able to support remote non-stop debugging, a remote stub needs
1401 to implement the non-stop mode remote protocol extensions, as
1402 described in the "Remote Non-Stop" section of the user manual. The
1403 GDB remote stub, gdbserver, has been adjusted to support these
1404 extensions on linux targets.
1406 * New commands (for set/show, see "New options" below)
1408 catch syscall [NAME(S) | NUMBER(S)]
1409 Catch system calls. Arguments, which should be names of system
1410 calls or their numbers, mean catch only those syscalls. Without
1411 arguments, every syscall will be caught. When the inferior issues
1412 any of the specified syscalls, GDB will stop and announce the system
1413 call, both when it is called and when its call returns. This
1414 feature is currently available with a native GDB running on the
1415 Linux Kernel, under the following architectures: x86, x86_64,
1416 PowerPC and PowerPC64.
1418 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1420 Search memory for a sequence of bytes.
1422 maint set python print-stack
1423 maint show python print-stack
1424 Show a stack trace when an error is encountered in a Python script.
1427 Invoke CODE by passing it to the Python interpreter.
1432 These allow macros to be defined, undefined, and listed
1436 Show operating system information about processes.
1439 List the inferiors currently under GDB's control.
1442 Switch focus to inferior number NUM.
1445 Detach from inferior number NUM.
1448 Kill inferior number NUM.
1452 set spu stop-on-load
1453 show spu stop-on-load
1454 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1456 set spu auto-flush-cache
1457 show spu auto-flush-cache
1458 Control whether to automatically flush the software-managed cache
1459 during Cell/B.E. debugging.
1461 set sh calling-convention
1462 show sh calling-convention
1463 Control the calling convention used when calling SH target functions.
1466 show debug timestamp
1467 Control display of timestamps with GDB debugging output.
1469 set disassemble-next-line
1470 show disassemble-next-line
1471 Control display of disassembled source lines or instructions when
1474 set remote noack-packet
1475 show remote noack-packet
1476 Set/show the use of remote protocol QStartNoAckMode packet. See above
1477 under "New remote packets."
1479 set remote query-attached-packet
1480 show remote query-attached-packet
1481 Control use of remote protocol `qAttached' (query-attached) packet.
1483 set remote read-siginfo-object
1484 show remote read-siginfo-object
1485 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1488 set remote write-siginfo-object
1489 show remote write-siginfo-object
1490 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1493 set remote reverse-continue
1494 show remote reverse-continue
1495 Control use of remote protocol 'bc' (reverse-continue) packet.
1497 set remote reverse-step
1498 show remote reverse-step
1499 Control use of remote protocol 'bs' (reverse-step) packet.
1501 set displaced-stepping
1502 show displaced-stepping
1503 Control displaced stepping mode. Displaced stepping is a way to
1504 single-step over breakpoints without removing them from the debuggee.
1505 Also known as "out-of-line single-stepping".
1508 show debug displaced
1509 Control display of debugging info for displaced stepping.
1511 maint set internal-error
1512 maint show internal-error
1513 Control what GDB does when an internal error is detected.
1515 maint set internal-warning
1516 maint show internal-warning
1517 Control what GDB does when an internal warning is detected.
1522 Use a wrapper program to launch programs for debugging.
1524 set multiple-symbols (all|ask|cancel)
1525 show multiple-symbols
1526 The value of this variable can be changed to adjust the debugger behavior
1527 when an expression or a breakpoint location contains an ambiguous symbol
1528 name (an overloaded function name, for instance).
1530 set breakpoint always-inserted
1531 show breakpoint always-inserted
1532 Keep breakpoints always inserted in the target, as opposed to inserting
1533 them when resuming the target, and removing them when the target stops.
1534 This option can improve debugger performance on slow remote targets.
1536 set arm fallback-mode (arm|thumb|auto)
1537 show arm fallback-mode
1538 set arm force-mode (arm|thumb|auto)
1540 These commands control how ARM GDB determines whether instructions
1541 are ARM or Thumb. The default for both settings is auto, which uses
1542 the current CPSR value for instructions without symbols; previous
1543 versions of GDB behaved as if "set arm fallback-mode arm".
1545 set disable-randomization
1546 show disable-randomization
1547 Standalone programs run with the virtual address space randomization enabled
1548 by default on some platforms. This option keeps the addresses stable across
1549 multiple debugging sessions.
1553 Control whether other threads are stopped or not when some thread hits
1558 Requests that asynchronous execution is enabled in the target, if available.
1559 In this case, it's possible to resume target in the background, and interact
1560 with GDB while the target is running. "show target-async" displays the
1561 current state of asynchronous execution of the target.
1563 set target-wide-charset
1564 show target-wide-charset
1565 The target-wide-charset is the name of the character set that GDB
1566 uses when printing characters whose type is wchar_t.
1568 set tcp auto-retry (on|off)
1570 set tcp connect-timeout
1571 show tcp connect-timeout
1572 These commands allow GDB to retry failed TCP connections to a remote stub
1573 with a specified timeout period; this is useful if the stub is launched
1574 in parallel with GDB but may not be ready to accept connections immediately.
1576 set libthread-db-search-path
1577 show libthread-db-search-path
1578 Control list of directories which GDB will search for appropriate
1581 set schedule-multiple (on|off)
1582 show schedule-multiple
1583 Allow GDB to resume all threads of all processes or only threads of
1584 the current process.
1588 Use more aggressive caching for accesses to the stack. This improves
1589 performance of remote debugging (particularly backtraces) without
1590 affecting correctness.
1592 set interactive-mode (on|off|auto)
1593 show interactive-mode
1594 Control whether GDB runs in interactive mode (on) or not (off).
1595 When in interactive mode, GDB waits for the user to answer all
1596 queries. Otherwise, GDB does not wait and assumes the default
1597 answer. When set to auto (the default), GDB determines which
1598 mode to use based on the stdin settings.
1603 For program forks, this is replaced by the new more generic `info
1604 inferiors' command. To list checkpoints, you can still use the
1605 `info checkpoints' command, which was an alias for the `info forks'
1609 Replaced by the new `inferior' command. To switch between
1610 checkpoints, you can still use the `restart' command, which was an
1611 alias for the `fork' command.
1614 This is removed, since some targets don't have a notion of
1615 processes. To switch between processes, you can still use the
1616 `inferior' command using GDB's own inferior number.
1619 For program forks, this is replaced by the new more generic `kill
1620 inferior' command. To delete a checkpoint, you can still use the
1621 `delete checkpoint' command, which was an alias for the `delete
1625 For program forks, this is replaced by the new more generic `detach
1626 inferior' command. To detach a checkpoint, you can still use the
1627 `detach checkpoint' command, which was an alias for the `detach
1630 * New native configurations
1632 x86/x86_64 Darwin i[34567]86-*-darwin*
1634 x86_64 MinGW x86_64-*-mingw*
1638 Lattice Mico32 lm32-*
1639 x86 DICOS i[34567]86-*-dicos*
1640 x86_64 DICOS x86_64-*-dicos*
1643 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1644 (mingw32ce) debugging.
1650 These commands were actually not implemented on any target.
1652 *** Changes in GDB 6.8
1654 * New native configurations
1656 NetBSD/hppa hppa*-*netbsd*
1657 Xtensa GNU/Linux xtensa*-*-linux*
1661 NetBSD/hppa hppa*-*-netbsd*
1662 Xtensa GNU/Lunux xtensa*-*-linux*
1664 * Change in command line behavior -- corefiles vs. process ids.
1666 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1667 attaching to process NUMBER fails, GDB no longer attempts to open a
1668 core file named NUMBER. Attaching to a program using the -c option
1669 is no longer supported. Instead, use the '-p' or '--pid' options.
1671 * GDB can now be built as a native debugger for debugging Windows x86
1672 (mingw32) Portable Executable (PE) programs.
1674 * Pending breakpoints no longer change their number when their address
1677 * GDB now supports breakpoints with multiple locations,
1678 including breakpoints on C++ constructors, inside C++ templates,
1679 and in inlined functions.
1681 * GDB's ability to debug optimized code has been improved. GDB more
1682 accurately identifies function bodies and lexical blocks that occupy
1683 more than one contiguous range of addresses.
1685 * Target descriptions can now describe registers for PowerPC.
1687 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1688 registers on PowerPC targets.
1690 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1691 targets even when the libthread_db library is not available.
1693 * The GDB remote stub, gdbserver, now supports the new file transfer
1694 commands (remote put, remote get, and remote delete).
1696 * The GDB remote stub, gdbserver, now supports run and attach in
1697 extended-remote mode.
1699 * hppa*64*-*-hpux11* target broken
1700 The debugger is unable to start a program and fails with the following
1701 error: "Error trying to get information about dynamic linker".
1702 The gdb-6.7 release is also affected.
1704 * GDB now supports the --enable-targets= configure option to allow
1705 building a single GDB executable that supports multiple remote
1706 target architectures.
1708 * GDB now supports debugging C and C++ programs which use the
1709 Decimal Floating Point extension. In addition, the PowerPC target
1710 now has a set of pseudo-registers to inspect decimal float values
1711 stored in two consecutive float registers.
1713 * The -break-insert MI command can optionally create pending
1716 * Improved support for debugging Ada
1717 Many improvements to the Ada language support have been made. These
1719 - Better support for Ada2005 interface types
1720 - Improved handling of arrays and slices in general
1721 - Better support for Taft-amendment types
1722 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1724 - Improved command completion in Ada
1727 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1732 set print frame-arguments (all|scalars|none)
1733 show print frame-arguments
1734 The value of this variable can be changed to control which argument
1735 values should be printed by the debugger when displaying a frame.
1740 Transfer files to and from a remote target, and delete remote files.
1747 Transfer files to and from a remote target, and delete remote files.
1749 * New remote packets
1756 Open, close, read, write, and delete files on the remote system.
1759 Attach to an existing process on the remote system, in extended-remote
1763 Run a new process on the remote system, in extended-remote mode.
1765 *** Changes in GDB 6.7
1767 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1768 bfd, libiberty and opcodes, as revealed by static analysis donated by
1769 Coverity, Inc. (http://scan.coverity.com).
1771 * When looking up multiply-defined global symbols, GDB will now prefer the
1772 symbol definition in the current shared library if it was built using the
1773 -Bsymbolic linker option.
1775 * When the Text User Interface (TUI) is not configured, GDB will now
1776 recognize the -tui command-line option and print a message that the TUI
1779 * The GDB remote stub, gdbserver, now has lower overhead for high
1780 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1782 * GDB for MIPS targets now autodetects whether a remote target provides
1783 32-bit or 64-bit register values.
1785 * Support for C++ member pointers has been improved.
1787 * GDB now understands XML target descriptions, which specify the
1788 target's overall architecture. GDB can read a description from
1789 a local file or over the remote serial protocol.
1791 * Vectors of single-byte data use a new integer type which is not
1792 automatically displayed as character or string data.
1794 * The /s format now works with the print command. It displays
1795 arrays of single-byte integers and pointers to single-byte integers
1798 * Target descriptions can now describe target-specific registers,
1799 for architectures which have implemented the support (currently
1800 only ARM, M68K, and MIPS).
1802 * GDB and the GDB remote stub, gdbserver, now support the XScale
1805 * The GDB remote stub, gdbserver, has been updated to support
1806 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1807 has been rewritten to use the standard GDB remote protocol.
1809 * GDB can now step into C++ functions which are called through thunks.
1811 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1813 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1814 layout. It also supports a TextSeg= and DataSeg= response when only
1815 segment base addresses (rather than offsets) are available.
1817 * The /i format now outputs any trailing branch delay slot instructions
1818 immediately following the last instruction within the count specified.
1820 * The GDB remote protocol "T" stop reply packet now supports a
1821 "library" response. Combined with the new "qXfer:libraries:read"
1822 packet, this response allows GDB to debug shared libraries on targets
1823 where the operating system manages the list of loaded libraries (e.g.
1824 Windows and SymbianOS).
1826 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1827 (DLLs) on Windows and Windows CE targets.
1829 * GDB now supports a faster verification that a .debug file matches its binary
1830 according to its build-id signature, if the signature is present.
1836 Enable or disable hardware flow control (RTS/CTS) on the serial port
1837 when debugging using remote targets.
1839 set mem inaccessible-by-default
1840 show mem inaccessible-by-default
1841 If the target supplies a memory map, for instance via the remote
1842 protocol's "qXfer:memory-map:read" packet, setting this variable
1843 prevents GDB from accessing memory outside the memory map. This
1844 is useful for targets with memory mapped registers or which react
1845 badly to accesses of unmapped address space.
1847 set breakpoint auto-hw
1848 show breakpoint auto-hw
1849 If the target supplies a memory map, for instance via the remote
1850 protocol's "qXfer:memory-map:read" packet, setting this variable
1851 lets GDB use hardware breakpoints automatically for memory regions
1852 where it can not use software breakpoints. This covers both the
1853 "break" command and internal breakpoints used for other commands
1854 including "next" and "finish".
1857 catch exception unhandled
1858 Stop the program execution when Ada exceptions are raised.
1861 Stop the program execution when an Ada assertion failed.
1865 Set an alternate system root for target files. This is a more
1866 general version of "set solib-absolute-prefix", which is now
1867 an alias to "set sysroot".
1870 Provide extended SPU facility status information. This set of
1871 commands is available only when debugging the Cell/B.E. SPU
1874 * New native configurations
1876 OpenBSD/sh sh*-*openbsd*
1879 unset tdesc filename
1881 Use the specified local file as an XML target description, and do
1882 not query the target for its built-in description.
1886 OpenBSD/sh sh*-*-openbsd*
1887 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1888 Toshiba Media Processor mep-elf
1890 * New remote packets
1893 Ignore the specified signals; pass them directly to the debugged program
1894 without stopping other threads or reporting them to GDB.
1896 qXfer:features:read:
1897 Read an XML target description from the target, which describes its
1902 Read or write contents of an spufs file on the target system. These
1903 packets are available only on the Cell/B.E. SPU architecture.
1905 qXfer:libraries:read:
1906 Report the loaded shared libraries. Combined with new "T" packet
1907 response, this packet allows GDB to debug shared libraries on
1908 targets where the operating system manages the list of loaded
1909 libraries (e.g. Windows and SymbianOS).
1913 Support for these obsolete configurations has been removed.
1921 i[34567]86-*-lynxos*
1922 i[34567]86-*-netware*
1923 i[34567]86-*-sco3.2v5*
1924 i[34567]86-*-sco3.2v4*
1926 i[34567]86-*-sysv4.2*
1929 i[34567]86-*-unixware2*
1930 i[34567]86-*-unixware*
1939 * Other removed features
1946 Various m68k-only ROM monitors.
1953 Various Renesas ROM monitors and debugging interfaces for SH and
1958 Support for a Macraigor serial interface to on-chip debugging.
1959 GDB does not directly support the newer parallel or USB
1964 A debug information format. The predecessor to DWARF 2 and
1965 DWARF 3, which are still supported.
1967 Support for the HP aCC compiler on HP-UX/PA-RISC
1969 SOM-encapsulated symbolic debugging information, automatic
1970 invocation of pxdb, and the aCC custom C++ ABI. This does not
1971 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1972 with aCC can still be debugged on an assembly level.
1974 MIPS ".pdr" sections
1976 A MIPS-specific format used to describe stack frame layout
1977 in debugging information.
1981 GDB could work with an older version of Guile to debug
1982 the interpreter and Scheme programs running in it.
1984 set mips stack-arg-size
1985 set mips saved-gpreg-size
1987 Use "set mips abi" to control parameter passing for MIPS.
1989 *** Changes in GDB 6.6
1994 Cell Broadband Engine SPU spu-elf
1996 * GDB can now be configured as a cross-debugger targeting native Windows
1997 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1998 running on a Windows system over TCP/IP to debug Windows programs.
2000 * The GDB remote stub, gdbserver, has been updated to support Windows and
2001 Cygwin debugging. Both single-threaded and multi-threaded programs are
2004 * The "set trust-readonly-sections" command works again. This command was
2005 broken in GDB 6.3, 6.4, and 6.5.
2007 * The "load" command now supports writing to flash memory, if the remote
2008 stub provides the required support.
2010 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2011 longer requires symbolic debug information (e.g. DWARF-2).
2016 unset substitute-path
2017 show substitute-path
2018 Manage a list of substitution rules that GDB uses to rewrite the name
2019 of the directories where the sources are located. This can be useful
2020 for instance when the sources were moved to a different location
2021 between compilation and debugging.
2025 Print each CLI command as it is executed. Each command is prefixed with
2026 a number of `+' symbols representing the nesting depth.
2027 The source command now has a `-v' option to enable the same feature.
2031 The ARM Demon monitor support (RDP protocol, "target rdp").
2033 Kernel Object Display, an embedded debugging feature which only worked with
2034 an obsolete version of Cisco IOS.
2036 The 'set download-write-size' and 'show download-write-size' commands.
2038 * New remote packets
2041 Tell a stub about GDB client features, and request remote target features.
2042 The first feature implemented is PacketSize, which allows the target to
2043 specify the size of packets it can handle - to minimize the number of
2044 packets required and improve performance when connected to a remote
2048 Fetch an OS auxilliary vector from the remote stub. This packet is a
2049 more efficient replacement for qPart:auxv:read.
2051 qXfer:memory-map:read:
2052 Fetch a memory map from the remote stub, including information about
2053 RAM, ROM, and flash memory devices.
2058 Erase and program a flash memory device.
2060 * Removed remote packets
2063 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2064 used it, and only gdbserver implemented it.
2066 *** Changes in GDB 6.5
2070 Renesas M32C/M16C m32c-elf
2072 Morpho Technologies ms1 ms1-elf
2076 init-if-undefined Initialize a convenience variable, but
2077 only if it doesn't already have a value.
2079 The following commands are presently only implemented for native GNU/Linux:
2081 checkpoint Save a snapshot of the program state.
2083 restart <n> Return the program state to a
2084 previously saved state.
2086 info checkpoints List currently saved checkpoints.
2088 delete-checkpoint <n> Delete a previously saved checkpoint.
2090 set|show detach-on-fork Tell gdb whether to detach from a newly
2091 forked process, or to keep debugging it.
2093 info forks List forks of the user program that
2094 are available to be debugged.
2096 fork <n> Switch to debugging one of several
2097 forks of the user program that are
2098 available to be debugged.
2100 delete-fork <n> Delete a fork from the list of forks
2101 that are available to be debugged (and
2102 kill the forked process).
2104 detach-fork <n> Delete a fork from the list of forks
2105 that are available to be debugged (and
2106 allow the process to continue).
2110 Morpho Technologies ms2 ms1-elf
2112 * Improved Windows host support
2114 GDB now builds as a cross debugger hosted on i686-mingw32, including
2115 native console support, and remote communications using either
2116 network sockets or serial ports.
2118 * Improved Modula-2 language support
2120 GDB can now print most types in the Modula-2 syntax. This includes:
2121 basic types, set types, record types, enumerated types, range types,
2122 pointer types and ARRAY types. Procedure var parameters are correctly
2123 printed and hexadecimal addresses and character constants are also
2124 written in the Modula-2 syntax. Best results can be obtained by using
2125 GNU Modula-2 together with the -gdwarf-2 command line option.
2129 The ARM rdi-share module.
2131 The Netware NLM debug server.
2133 *** Changes in GDB 6.4
2135 * New native configurations
2137 OpenBSD/arm arm*-*-openbsd*
2138 OpenBSD/mips64 mips64-*-openbsd*
2142 Morpho Technologies ms1 ms1-elf
2144 * New command line options
2146 --batch-silent As for --batch, but totally silent.
2147 --return-child-result The debugger will exist with the same value
2148 the child (debugged) program exited with.
2149 --eval-command COMMAND, -ex COMMAND
2150 Execute a single GDB CLI command. This may be
2151 specified multiple times and in conjunction
2152 with the --command (-x) option.
2154 * Deprecated commands removed
2156 The following commands, that were deprecated in 2000, have been
2160 set|show arm disassembly-flavor set|show arm disassembler
2161 othernames set arm disassembler
2162 set|show remotedebug set|show debug remote
2163 set|show archdebug set|show debug arch
2164 set|show eventdebug set|show debug event
2167 * New BSD user-level threads support
2169 It is now possible to debug programs using the user-level threads
2170 library on OpenBSD and FreeBSD. Currently supported (target)
2173 FreeBSD/amd64 x86_64-*-freebsd*
2174 FreeBSD/i386 i386-*-freebsd*
2175 OpenBSD/i386 i386-*-openbsd*
2177 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2178 are not yet supported.
2180 * New support for Matsushita MN10300 w/sim added
2181 (Work in progress). mn10300-elf.
2183 * REMOVED configurations and files
2185 VxWorks and the XDR protocol *-*-vxworks
2186 Motorola MCORE mcore-*-*
2187 National Semiconductor NS32000 ns32k-*-*
2189 * New "set print array-indexes" command
2191 After turning this setting "on", GDB prints the index of each element
2192 when displaying arrays. The default is "off" to preserve the previous
2195 * VAX floating point support
2197 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2199 * User-defined command support
2201 In addition to using $arg0..$arg9 for argument passing, it is now possible
2202 to use $argc to determine now many arguments have been passed. See the
2203 section on user-defined commands in the user manual for more information.
2205 *** Changes in GDB 6.3:
2207 * New command line option
2209 GDB now accepts -l followed by a number to set the timeout for remote
2212 * GDB works with GCC -feliminate-dwarf2-dups
2214 GDB now supports a more compact representation of DWARF-2 debug
2215 information using DW_FORM_ref_addr references. These are produced
2216 by GCC with the option -feliminate-dwarf2-dups and also by some
2217 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2218 to use -feliminate-dwarf2-dups.
2220 * Internationalization
2222 When supported by the host system, GDB will be built with
2223 internationalization (libintl). The task of marking up the sources is
2224 continued, we're looking forward to our first translation.
2228 Initial support for debugging programs compiled with the GNAT
2229 implementation of the Ada programming language has been integrated
2230 into GDB. In this release, support is limited to expression evaluation.
2232 * New native configurations
2234 GNU/Linux/m32r m32r-*-linux-gnu
2238 GDB's remote protocol now includes support for the 'p' packet. This
2239 packet is used to fetch individual registers from a remote inferior.
2241 * END-OF-LIFE registers[] compatibility module
2243 GDB's internal register infrastructure has been completely rewritten.
2244 The new infrastructure making possible the implementation of key new
2245 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2248 GDB 6.3 will be the last release to include the the registers[]
2249 compatibility module that allowed out-of-date configurations to
2250 continue to work. This change directly impacts the following
2260 powerpc bdm protocol
2262 Unless there is activity to revive these configurations, they will be
2263 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2265 * OBSOLETE configurations and files
2267 Configurations that have been declared obsolete in this release have
2268 been commented out. Unless there is activity to revive these
2269 configurations, the next release of GDB will have their sources
2270 permanently REMOVED.
2279 *** Changes in GDB 6.2.1:
2281 * MIPS `break main; run' gave an heuristic-fence-post warning
2283 When attempting to run even a simple program, a warning about
2284 heuristic-fence-post being hit would be reported. This problem has
2287 * MIPS IRIX 'long double' crashed GDB
2289 When examining a long double variable, GDB would get a segmentation
2290 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2291 IRIX long double values).
2295 A bug in the VAX stack code was causing problems with the "next"
2296 command. This problem has been fixed.
2298 *** Changes in GDB 6.2:
2300 * Fix for ``many threads''
2302 On GNU/Linux systems that use the NPTL threads library, a program
2303 rapidly creating and deleting threads would confuse GDB leading to the
2306 ptrace: No such process.
2307 thread_db_get_info: cannot get thread info: generic error
2309 This problem has been fixed.
2311 * "-async" and "-noasync" options removed.
2313 Support for the broken "-noasync" option has been removed (it caused
2316 * New ``start'' command.
2318 This command runs the program until the begining of the main procedure.
2320 * New BSD Kernel Data Access Library (libkvm) interface
2322 Using ``target kvm'' it is now possible to debug kernel core dumps and
2323 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2324 platforms. Currently supported (native-only) configurations are:
2326 FreeBSD/amd64 x86_64-*-freebsd*
2327 FreeBSD/i386 i?86-*-freebsd*
2328 NetBSD/i386 i?86-*-netbsd*
2329 NetBSD/m68k m68*-*-netbsd*
2330 NetBSD/sparc sparc-*-netbsd*
2331 OpenBSD/amd64 x86_64-*-openbsd*
2332 OpenBSD/i386 i?86-*-openbsd*
2333 OpenBSD/m68k m68*-openbsd*
2334 OpenBSD/sparc sparc-*-openbsd*
2336 * Signal trampoline code overhauled
2338 Many generic problems with GDB's signal handling code have been fixed.
2339 These include: backtraces through non-contiguous stacks; recognition
2340 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2341 call; backtrace through a signal trampoline; step into and out of
2342 signal handlers; and single-stepping in the signal trampoline.
2344 Please note that kernel bugs are a limiting factor here. These
2345 features have been shown to work on an s390 GNU/Linux system that
2346 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2348 * Cygwin support for DWARF 2 added.
2350 * New native configurations
2352 GNU/Linux/hppa hppa*-*-linux*
2353 OpenBSD/hppa hppa*-*-openbsd*
2354 OpenBSD/m68k m68*-*-openbsd*
2355 OpenBSD/m88k m88*-*-openbsd*
2356 OpenBSD/powerpc powerpc-*-openbsd*
2357 NetBSD/vax vax-*-netbsd*
2358 OpenBSD/vax vax-*-openbsd*
2360 * END-OF-LIFE frame compatibility module
2362 GDB's internal frame infrastructure has been completely rewritten.
2363 The new infrastructure making it possible to support key new features
2364 including DWARF 2 Call Frame Information. To aid in the task of
2365 migrating old configurations to this new infrastructure, a
2366 compatibility module, that allowed old configurations to continue to
2367 work, was also included.
2369 GDB 6.2 will be the last release to include this frame compatibility
2370 module. This change directly impacts the following configurations:
2380 Unless there is activity to revive these configurations, they will be
2381 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2383 * REMOVED configurations and files
2385 Sun 3, running SunOS 3 m68*-*-sunos3*
2386 Sun 3, running SunOS 4 m68*-*-sunos4*
2387 Sun 2, running SunOS 3 m68000-*-sunos3*
2388 Sun 2, running SunOS 4 m68000-*-sunos4*
2389 Motorola 680x0 running LynxOS m68*-*-lynxos*
2390 AT&T 3b1/Unix pc m68*-att-*
2391 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2392 decstation mips-dec-* mips-little-*
2393 riscos mips-*-riscos* mips-*-sysv*
2394 sonymips mips-sony-*
2395 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2397 *** Changes in GDB 6.1.1:
2399 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2401 The TUI (Text-mode User Interface) is now built as part of a default
2402 GDB configuration. It is enabled by either selecting the TUI with the
2403 command line option "-i=tui" or by running the separate "gdbtui"
2404 program. For more information on the TUI, see the manual "Debugging
2407 * Pending breakpoint support (also included in GDB 6.1)
2409 Support has been added to allow you to specify breakpoints in shared
2410 libraries that have not yet been loaded. If a breakpoint location
2411 cannot be found, and the "breakpoint pending" option is set to auto,
2412 GDB queries you if you wish to make the breakpoint pending on a future
2413 shared-library load. If and when GDB resolves the breakpoint symbol,
2414 the pending breakpoint is removed as one or more regular breakpoints
2417 Pending breakpoints are very useful for GCJ Java debugging.
2419 * Fixed ISO-C build problems
2421 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2422 non ISO-C code that stopped them being built using a more strict ISO-C
2423 compiler (e.g., IBM's C compiler).
2425 * Fixed build problem on IRIX 5
2427 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2428 wasn't able to compile compile on an IRIX 5 system.
2430 * Added execute permission to gdb/gdbserver/configure
2432 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2433 permission. This bug would cause configure to fail on a number of
2434 systems (Solaris, IRIX). Ref: server/519.
2436 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2438 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2439 has been updated to use constant array sizes.
2441 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2443 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2444 its generated DWARF Call Frame Info. This encoding was causing GDB to
2445 panic, that panic has been fixed. Ref: gdb/1628.
2447 * Fixed a problem when examining parameters in shared library code.
2449 When examining parameters in optimized shared library code generated
2450 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2451 not available''. GDB now correctly displays the variable's value.
2453 *** Changes in GDB 6.1:
2455 * Removed --with-mmalloc
2457 Support for the mmalloc memory manager has been removed, as it
2458 conflicted with the internal gdb byte cache.
2460 * Changes in AMD64 configurations
2462 The AMD64 target now includes the %cs and %ss registers. As a result
2463 the AMD64 remote protocol has changed; this affects the floating-point
2464 and SSE registers. If you rely on those registers for your debugging,
2465 you should upgrade gdbserver on the remote side.
2467 * Revised SPARC target
2469 The SPARC target has been completely revised, incorporating the
2470 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2471 support for LynxOS and SunOS 4 has been dropped. Calling functions
2472 from within GDB on operating systems with a non-executable stack
2473 (Solaris, OpenBSD) now works.
2477 GDB has a new C++ demangler which does a better job on the mangled
2478 names generated by current versions of g++. It also runs faster, so
2479 with this and other changes gdb should now start faster on large C++
2482 * DWARF 2 Location Expressions
2484 GDB support for location expressions has been extended to support function
2485 arguments and frame bases. Older versions of GDB could crash when they
2488 * C++ nested types and namespaces
2490 GDB's support for nested types and namespaces in C++ has been
2491 improved, especially if you use the DWARF 2 debugging format. (This
2492 is the default for recent versions of GCC on most platforms.)
2493 Specifically, if you have a class "Inner" defined within a class or
2494 namespace "Outer", then GDB realizes that the class's name is
2495 "Outer::Inner", not simply "Inner". This should greatly reduce the
2496 frequency of complaints about not finding RTTI symbols. In addition,
2497 if you are stopped at inside of a function defined within a namespace,
2498 GDB modifies its name lookup accordingly.
2500 * New native configurations
2502 NetBSD/amd64 x86_64-*-netbsd*
2503 OpenBSD/amd64 x86_64-*-openbsd*
2504 OpenBSD/alpha alpha*-*-openbsd*
2505 OpenBSD/sparc sparc-*-openbsd*
2506 OpenBSD/sparc64 sparc64-*-openbsd*
2508 * New debugging protocols
2510 M32R with SDI protocol m32r-*-elf*
2512 * "set prompt-escape-char" command deleted.
2514 The command "set prompt-escape-char" has been deleted. This command,
2515 and its very obscure effet on GDB's prompt, was never documented,
2516 tested, nor mentioned in the NEWS file.
2518 * OBSOLETE configurations and files
2520 Configurations that have been declared obsolete in this release have
2521 been commented out. Unless there is activity to revive these
2522 configurations, the next release of GDB will have their sources
2523 permanently REMOVED.
2525 Sun 3, running SunOS 3 m68*-*-sunos3*
2526 Sun 3, running SunOS 4 m68*-*-sunos4*
2527 Sun 2, running SunOS 3 m68000-*-sunos3*
2528 Sun 2, running SunOS 4 m68000-*-sunos4*
2529 Motorola 680x0 running LynxOS m68*-*-lynxos*
2530 AT&T 3b1/Unix pc m68*-att-*
2531 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2532 decstation mips-dec-* mips-little-*
2533 riscos mips-*-riscos* mips-*-sysv*
2534 sonymips mips-sony-*
2535 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2537 * REMOVED configurations and files
2539 SGI Irix-4.x mips-sgi-irix4 or iris4
2540 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2541 Z8000 simulator z8k-zilog-none or z8ksim
2542 Matsushita MN10200 w/simulator mn10200-*-*
2543 H8/500 simulator h8500-hitachi-hms or h8500hms
2544 HP/PA running BSD hppa*-*-bsd*
2545 HP/PA running OSF/1 hppa*-*-osf*
2546 HP/PA Pro target hppa*-*-pro*
2547 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2548 386BSD i[3456]86-*-bsd*
2549 Sequent family i[3456]86-sequent-sysv4*
2550 i[3456]86-sequent-sysv*
2551 i[3456]86-sequent-bsd*
2552 SPARC running LynxOS sparc-*-lynxos*
2553 SPARC running SunOS 4 sparc-*-sunos4*
2554 Tsqware Sparclet sparclet-*-*
2555 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2557 *** Changes in GDB 6.0:
2561 Support for debugging the Objective-C programming language has been
2562 integrated into GDB.
2564 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2566 DWARF 2's Call Frame Information makes available compiler generated
2567 information that more exactly describes the program's run-time stack.
2568 By using this information, GDB is able to provide more robust stack
2571 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2572 have been updated to use a new backtrace mechanism which includes
2573 DWARF 2 CFI support.
2577 GDB's remote protocol has been extended to include support for hosted
2578 file I/O (where the remote target uses GDB's file system). See GDB's
2579 remote protocol documentation for details.
2581 * All targets using the new architecture framework.
2583 All of GDB's targets have been updated to use the new internal
2584 architecture framework. The way is now open for future GDB releases
2585 to include cross-architecture native debugging support (i386 on amd64,
2588 * GNU/Linux's Thread Local Storage (TLS)
2590 GDB now includes support for for the GNU/Linux implementation of
2591 per-thread variables.
2593 * GNU/Linux's Native POSIX Thread Library (NPTL)
2595 GDB's thread code has been updated to work with either the new
2596 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2598 * Separate debug info.
2600 GDB, in conjunction with BINUTILS, now supports a mechanism for
2601 automatically loading debug information from a separate file. Instead
2602 of shipping full debug and non-debug versions of system libraries,
2603 system integrators can now instead ship just the stripped libraries
2604 and optional debug files.
2606 * DWARF 2 Location Expressions
2608 DWARF 2 Location Expressions allow the compiler to more completely
2609 describe the location of variables (even in optimized code) to the
2612 GDB now includes preliminary support for location expressions (support
2613 for DW_OP_piece is still missing).
2617 A number of long standing bugs that caused GDB to die while starting a
2618 Java application have been fixed. GDB's Java support is now
2619 considered "useable".
2621 * GNU/Linux support for fork, vfork, and exec.
2623 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2624 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2627 * GDB supports logging output to a file
2629 There are two new commands, "set logging" and "show logging", which can be
2630 used to capture GDB's output to a file.
2632 * The meaning of "detach" has changed for gdbserver
2634 The "detach" command will now resume the application, as documented. To
2635 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2638 * d10v, m68hc11 `regs' command deprecated
2640 The `info registers' command has been updated so that it displays the
2641 registers using a format identical to the old `regs' command.
2645 A new command, "maint set profile on/off", has been added. This command can
2646 be used to enable or disable profiling while running GDB, to profile a
2647 session or a set of commands. In addition there is a new configure switch,
2648 "--enable-profiling", which will cause GDB to be compiled with profiling
2649 data, for more informative profiling results.
2651 * Default MI syntax changed to "mi2".
2653 The default MI (machine interface) syntax, enabled by the command line
2654 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2655 "mi1", can be enabled by specifying the option "-i=mi1".
2657 Support for the original "mi0" syntax (included in GDB 5.0) has been
2660 Fix for gdb/192: removed extraneous space when displaying frame level.
2661 Fix for gdb/672: update changelist is now output in mi list format.
2662 Fix for gdb/702: a -var-assign that updates the value now shows up
2663 in a subsequent -var-update.
2665 * New native configurations.
2667 FreeBSD/amd64 x86_64-*-freebsd*
2669 * Multi-arched targets.
2671 HP/PA HPUX11 hppa*-*-hpux*
2672 Renesas M32R/D w/simulator m32r-*-elf*
2674 * OBSOLETE configurations and files
2676 Configurations that have been declared obsolete in this release have
2677 been commented out. Unless there is activity to revive these
2678 configurations, the next release of GDB will have their sources
2679 permanently REMOVED.
2681 Z8000 simulator z8k-zilog-none or z8ksim
2682 Matsushita MN10200 w/simulator mn10200-*-*
2683 H8/500 simulator h8500-hitachi-hms or h8500hms
2684 HP/PA running BSD hppa*-*-bsd*
2685 HP/PA running OSF/1 hppa*-*-osf*
2686 HP/PA Pro target hppa*-*-pro*
2687 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2688 Sequent family i[3456]86-sequent-sysv4*
2689 i[3456]86-sequent-sysv*
2690 i[3456]86-sequent-bsd*
2691 Tsqware Sparclet sparclet-*-*
2692 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2694 * REMOVED configurations and files
2697 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2698 IBM AIX PS/2 i[3456]86-*-aix
2699 i386 running Mach 3.0 i[3456]86-*-mach3*
2700 i386 running Mach i[3456]86-*-mach*
2701 i386 running OSF/1 i[3456]86-*osf1mk*
2702 HP/Apollo 68k Family m68*-apollo*-sysv*,
2704 m68*-hp-bsd*, m68*-hp-hpux*
2705 Argonaut Risc Chip (ARC) arc-*-*
2706 Mitsubishi D30V d30v-*-*
2707 Fujitsu FR30 fr30-*-elf*
2708 OS/9000 i[34]86-*-os9k
2709 I960 with MON960 i960-*-coff
2711 * MIPS $fp behavior changed
2713 The convenience variable $fp, for the MIPS, now consistently returns
2714 the address of the current frame's base. Previously, depending on the
2715 context, $fp could refer to either $sp or the current frame's base
2716 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2717 The GNU Source-Level Debugger''.
2719 *** Changes in GDB 5.3:
2721 * GNU/Linux shared library multi-threaded performance improved.
2723 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2724 `/proc', in preference to `ptrace' for memory reads. This may result
2725 in an improvement in the start-up time of multi-threaded, shared
2726 library applications when run under GDB. One GDB user writes: ``loads
2727 shared libs like mad''.
2729 * ``gdbserver'' now supports multi-threaded applications on some targets
2731 Support for debugging multi-threaded applications which use
2732 the GNU/Linux LinuxThreads package has been added for
2733 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2734 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2736 * GDB now supports C/C++ preprocessor macros.
2738 GDB now expands preprocessor macro invocations in C/C++ expressions,
2739 and provides various commands for showing macro definitions and how
2742 The new command `macro expand EXPRESSION' expands any macro
2743 invocations in expression, and shows the result.
2745 The new command `show macro MACRO-NAME' shows the definition of the
2746 macro named MACRO-NAME, and where it was defined.
2748 Most compilers don't include information about macros in the debugging
2749 information by default. In GCC 3.1, for example, you need to compile
2750 your program with the options `-gdwarf-2 -g3'. If the macro
2751 information is present in the executable, GDB will read it.
2753 * Multi-arched targets.
2755 DEC Alpha (partial) alpha*-*-*
2756 DEC VAX (partial) vax-*-*
2758 National Semiconductor NS32000 (partial) ns32k-*-*
2759 Motorola 68000 (partial) m68k-*-*
2760 Motorola MCORE mcore-*-*
2764 Fujitsu FRV architecture added by Red Hat frv*-*-*
2767 * New native configurations
2769 Alpha NetBSD alpha*-*-netbsd*
2770 SH NetBSD sh*-*-netbsdelf*
2771 MIPS NetBSD mips*-*-netbsd*
2772 UltraSPARC NetBSD sparc64-*-netbsd*
2774 * OBSOLETE configurations and files
2776 Configurations that have been declared obsolete in this release have
2777 been commented out. Unless there is activity to revive these
2778 configurations, the next release of GDB will have their sources
2779 permanently REMOVED.
2781 Mitsubishi D30V d30v-*-*
2782 OS/9000 i[34]86-*-os9k
2783 IBM AIX PS/2 i[3456]86-*-aix
2784 Fujitsu FR30 fr30-*-elf*
2785 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2786 Argonaut Risc Chip (ARC) arc-*-*
2787 i386 running Mach 3.0 i[3456]86-*-mach3*
2788 i386 running Mach i[3456]86-*-mach*
2789 i386 running OSF/1 i[3456]86-*osf1mk*
2790 HP/Apollo 68k Family m68*-apollo*-sysv*,
2792 m68*-hp-bsd*, m68*-hp-hpux*
2793 I960 with MON960 i960-*-coff
2795 * OBSOLETE languages
2797 CHILL, a Pascal like language used by telecommunications companies.
2799 * REMOVED configurations and files
2801 AMD 29k family via UDI a29k-amd-udi, udi29k
2802 A29K VxWorks a29k-*-vxworks
2803 AMD 29000 embedded, using EBMON a29k-none-none
2804 AMD 29000 embedded with COFF a29k-none-coff
2805 AMD 29000 embedded with a.out a29k-none-aout
2807 testsuite/gdb.hp/gdb.threads-hp/ directory
2809 * New command "set max-user-call-depth <nnn>"
2811 This command allows the user to limit the call depth of user-defined
2812 commands. The default is 1024.
2814 * Changes in FreeBSD/i386 native debugging.
2816 Support for the "generate-core-file" has been added.
2818 * New commands "dump", "append", and "restore".
2820 These commands allow data to be copied from target memory
2821 to a bfd-format or binary file (dump and append), and back
2822 from a file into memory (restore).
2824 * Improved "next/step" support on multi-processor Alpha Tru64.
2826 The previous single-step mechanism could cause unpredictable problems,
2827 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2828 of a software single-step mechanism prevents this.
2830 *** Changes in GDB 5.2.1:
2838 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2839 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2840 Fix, by Joel Brobecker imported from mainline.
2842 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2843 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2844 Fix, by Fred Fish, imported from mainline.
2846 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2847 Surprisingly enough, it works now.
2848 By Michal Ludvig, imported from mainline.
2850 i386 hardware watchpoint support:
2851 avoid misses on second run for some targets.
2852 By Pierre Muller, imported from mainline.
2854 *** Changes in GDB 5.2:
2856 * New command "set trust-readonly-sections on[off]".
2858 This command is a hint that tells gdb that read-only sections
2859 really are read-only (ie. that their contents will not change).
2860 In this mode, gdb will go to the object file rather than the
2861 target to read memory from read-only sections (such as ".text").
2862 This can be a significant performance improvement on some
2863 (notably embedded) targets.
2865 * New command "generate-core-file" (or "gcore").
2867 This new gdb command allows the user to drop a core file of the child
2868 process state at any time. So far it's been implemented only for
2869 GNU/Linux and Solaris, but should be relatively easily ported to other
2870 hosts. Argument is core file name (defaults to core.<pid>).
2872 * New command line option
2874 GDB now accepts --pid or -p followed by a process id.
2876 * Change in command line behavior -- corefiles vs. process ids.
2878 There is a subtle behavior in the way in which GDB handles
2879 command line arguments. The first non-flag argument is always
2880 a program to debug, but the second non-flag argument may either
2881 be a corefile or a process id. Previously, GDB would attempt to
2882 open the second argument as a corefile, and if that failed, would
2883 issue a superfluous error message and then attempt to attach it as
2884 a process. Now, if the second argument begins with a non-digit,
2885 it will be treated as a corefile. If it begins with a digit,
2886 GDB will attempt to attach it as a process, and if no such process
2887 is found, will then attempt to open it as a corefile.
2889 * Changes in ARM configurations.
2891 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2892 configuration is fully multi-arch.
2894 * New native configurations
2896 ARM NetBSD arm*-*-netbsd*
2897 x86 OpenBSD i[3456]86-*-openbsd*
2898 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2899 Sparc64 running FreeBSD sparc64-*-freebsd*
2903 Sanyo XStormy16 xstormy16-elf
2905 * OBSOLETE configurations and files
2907 Configurations that have been declared obsolete in this release have
2908 been commented out. Unless there is activity to revive these
2909 configurations, the next release of GDB will have their sources
2910 permanently REMOVED.
2912 AMD 29k family via UDI a29k-amd-udi, udi29k
2913 A29K VxWorks a29k-*-vxworks
2914 AMD 29000 embedded, using EBMON a29k-none-none
2915 AMD 29000 embedded with COFF a29k-none-coff
2916 AMD 29000 embedded with a.out a29k-none-aout
2918 testsuite/gdb.hp/gdb.threads-hp/ directory
2920 * REMOVED configurations and files
2922 TI TMS320C80 tic80-*-*
2924 PowerPC Solaris powerpcle-*-solaris*
2925 PowerPC Windows NT powerpcle-*-cygwin32
2926 PowerPC Netware powerpc-*-netware*
2927 Harris/CXUX m88k m88*-harris-cxux*
2928 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2929 ns32k-utek-sysv* ns32k-utek-*
2930 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2931 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2932 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2933 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2934 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2936 * Changes to command line processing
2938 The new `--args' feature can be used to specify command-line arguments
2939 for the inferior from gdb's command line.
2941 * Changes to key bindings
2943 There is a new `operate-and-get-next' function bound to `C-o'.
2945 *** Changes in GDB 5.1.1
2947 Fix compile problem on DJGPP.
2949 Fix a problem with floating-point registers on the i386 being
2952 Fix to stop GDB crashing on .debug_str debug info.
2954 Numerous documentation fixes.
2956 Numerous testsuite fixes.
2958 *** Changes in GDB 5.1:
2960 * New native configurations
2962 Alpha FreeBSD alpha*-*-freebsd*
2963 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2964 MIPS GNU/Linux mips*-*-linux*
2965 MIPS SGI Irix 6.x mips*-sgi-irix6*
2966 ia64 AIX ia64-*-aix*
2967 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2971 Motorola 68HC11 and 68HC12 m68hc11-elf
2973 UltraSparc running GNU/Linux sparc64-*-linux*
2975 * OBSOLETE configurations and files
2977 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2978 Harris/CXUX m88k m88*-harris-cxux*
2979 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2980 ns32k-utek-sysv* ns32k-utek-*
2981 TI TMS320C80 tic80-*-*
2983 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2984 PowerPC Solaris powerpcle-*-solaris*
2985 PowerPC Windows NT powerpcle-*-cygwin32
2986 PowerPC Netware powerpc-*-netware*
2987 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2988 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2989 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2990 Apple Macintosh (MPW) host N/A
2992 stuff.c (Program to stuff files into a specially prepared space in kdb)
2993 kdb-start.c (Main loop for the standalone kernel debugger)
2995 Configurations that have been declared obsolete in this release have
2996 been commented out. Unless there is activity to revive these
2997 configurations, the next release of GDB will have their sources
2998 permanently REMOVED.
3000 * REMOVED configurations and files
3002 Altos 3068 m68*-altos-*
3003 Convex c1-*-*, c2-*-*
3005 ARM RISCix arm-*-* (as host)
3009 * GDB has been converted to ISO C.
3011 GDB's source code has been converted to ISO C. In particular, the
3012 sources are fully protoized, and rely on standard headers being
3017 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3019 * The MI enabled by default.
3021 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3022 revised and enabled by default. Packages which use GDB as a debugging
3023 engine behind a UI or another front end are encouraged to switch to
3024 using the GDB/MI interface, instead of the old annotations interface
3025 which is now deprecated.
3027 * Support for debugging Pascal programs.
3029 GDB now includes support for debugging Pascal programs. The following
3030 main features are supported:
3032 - Pascal-specific data types such as sets;
3034 - automatic recognition of Pascal sources based on file-name
3037 - Pascal-style display of data types, variables, and functions;
3039 - a Pascal expression parser.
3041 However, some important features are not yet supported.
3043 - Pascal string operations are not supported at all;
3045 - there are some problems with boolean types;
3047 - Pascal type hexadecimal constants are not supported
3048 because they conflict with the internal variables format;
3050 - support for Pascal objects and classes is not full yet;
3052 - unlike Pascal, GDB is case-sensitive for symbol names.
3054 * Changes in completion.
3056 Commands such as `shell', `run' and `set args', which pass arguments
3057 to inferior programs, now complete on file names, similar to what
3058 users expect at the shell prompt.
3060 Commands which accept locations, such as `disassemble', `print',
3061 `breakpoint', `until', etc. now complete on filenames as well as
3062 program symbols. Thus, if you type "break foob TAB", and the source
3063 files linked into the programs include `foobar.c', that file name will
3064 be one of the candidates for completion. However, file names are not
3065 considered for completion after you typed a colon that delimits a file
3066 name from a name of a function in that file, as in "break foo.c:bar".
3068 `set demangle-style' completes on available demangling styles.
3070 * New platform-independent commands:
3072 It is now possible to define a post-hook for a command as well as a
3073 hook that runs before the command. For more details, see the
3074 documentation of `hookpost' in the GDB manual.
3076 * Changes in GNU/Linux native debugging.
3078 Support for debugging multi-threaded programs has been completely
3079 revised for all platforms except m68k and sparc. You can now debug as
3080 many threads as your system allows you to have.
3082 Attach/detach is supported for multi-threaded programs.
3084 Support for SSE registers was added for x86. This doesn't work for
3085 multi-threaded programs though.
3087 * Changes in MIPS configurations.
3089 Multi-arch support is enabled for all MIPS configurations.
3091 GDB can now be built as native debugger on SGI Irix 6.x systems for
3092 debugging n32 executables. (Debugging 64-bit executables is not yet
3095 * Unified support for hardware watchpoints in all x86 configurations.
3097 Most (if not all) native x86 configurations support hardware-assisted
3098 breakpoints and watchpoints in a unified manner. This support
3099 implements debug register sharing between watchpoints, which allows to
3100 put a virtually infinite number of watchpoints on the same address,
3101 and also supports watching regions up to 16 bytes with several debug
3104 The new maintenance command `maintenance show-debug-regs' toggles
3105 debugging print-outs in functions that insert, remove, and test
3106 watchpoints and hardware breakpoints.
3108 * Changes in the DJGPP native configuration.
3110 New command ``info dos sysinfo'' displays assorted information about
3111 the CPU, OS, memory, and DPMI server.
3113 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3114 display information about segment descriptors stored in GDT, LDT, and
3117 New commands ``info dos pde'' and ``info dos pte'' display entries
3118 from Page Directory and Page Tables (for now works with CWSDPMI only).
3119 New command ``info dos address-pte'' displays the Page Table entry for
3120 a given linear address.
3122 GDB can now pass command lines longer than 126 characters to the
3123 program being debugged (requires an update to the libdbg.a library
3124 which is part of the DJGPP development kit).
3126 DWARF2 debug info is now supported.
3128 It is now possible to `step' and `next' through calls to `longjmp'.
3130 * Changes in documentation.
3132 All GDB documentation was converted to GFDL, the GNU Free
3133 Documentation License.
3135 Tracepoints-related commands are now fully documented in the GDB
3138 TUI, the Text-mode User Interface, is now documented in the manual.
3140 Tracepoints-related commands are now fully documented in the GDB
3143 The "GDB Internals" manual now has an index. It also includes
3144 documentation of `ui_out' functions, GDB coding standards, x86
3145 hardware watchpoints, and memory region attributes.
3147 * GDB's version number moved to ``version.in''
3149 The Makefile variable VERSION has been replaced by the file
3150 ``version.in''. People creating GDB distributions should update the
3151 contents of this file.
3155 GUD support is now a standard part of the EMACS distribution.
3157 *** Changes in GDB 5.0:
3159 * Improved support for debugging FP programs on x86 targets
3161 Unified and much-improved support for debugging floating-point
3162 programs on all x86 targets. In particular, ``info float'' now
3163 displays the FP registers in the same format on all x86 targets, with
3164 greater level of detail.
3166 * Improvements and bugfixes in hardware-assisted watchpoints
3168 It is now possible to watch array elements, struct members, and
3169 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3170 on x86 targets no longer erroneously trigger when the address is
3173 * Improvements in the native DJGPP version of GDB
3175 The distribution now includes all the scripts and auxiliary files
3176 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3177 machines ``out of the box''.
3179 The DJGPP version can now debug programs that use signals. It is
3180 possible to catch signals that happened in the debuggee, deliver
3181 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3182 would kill the program being debugged.) Programs that hook hardware
3183 interrupts (keyboard, timer, etc.) can also be debugged.
3185 It is now possible to debug DJGPP programs that redirect their
3186 standard handles or switch them to raw (as opposed to cooked) mode, or
3187 even close them. The command ``run < foo > bar'' works as expected,
3188 and ``info terminal'' reports useful information about the debuggee's
3189 terminal, including raw/cooked mode, redirection, etc.
3191 The DJGPP version now uses termios functions for console I/O, which
3192 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3195 DOS-style file names with drive letters are now fully supported by
3198 It is now possible to debug DJGPP programs that switch their working
3199 directory. It is also possible to rerun the debuggee any number of
3200 times without restarting GDB; thus, you can use the same setup,
3201 breakpoints, etc. for many debugging sessions.
3203 * New native configurations
3205 ARM GNU/Linux arm*-*-linux*
3206 PowerPC GNU/Linux powerpc-*-linux*
3210 Motorola MCore mcore-*-*
3211 x86 VxWorks i[3456]86-*-vxworks*
3212 PowerPC VxWorks powerpc-*-vxworks*
3213 TI TMS320C80 tic80-*-*
3215 * OBSOLETE configurations
3217 Altos 3068 m68*-altos-*
3218 Convex c1-*-*, c2-*-*
3220 ARM RISCix arm-*-* (as host)
3223 Configurations that have been declared obsolete will be commented out,
3224 but the code will be left in place. If there is no activity to revive
3225 these configurations before the next release of GDB, the sources will
3226 be permanently REMOVED.
3228 * Gould support removed
3230 Support for the Gould PowerNode and NP1 has been removed.
3232 * New features for SVR4
3234 On SVR4 native platforms (such as Solaris), if you attach to a process
3235 without first loading a symbol file, GDB will now attempt to locate and
3236 load symbols from the running process's executable file.
3238 * Many C++ enhancements
3240 C++ support has been greatly improved. Overload resolution now works properly
3241 in almost all cases. RTTI support is on the way.
3243 * Remote targets can connect to a sub-program
3245 A popen(3) style serial-device has been added. This device starts a
3246 sub-process (such as a stand-alone simulator) and then communicates
3247 with that. The sub-program to run is specified using the syntax
3248 ``|<program> <args>'' vis:
3250 (gdb) set remotedebug 1
3251 (gdb) target extended-remote |mn10300-elf-sim program-args
3253 * MIPS 64 remote protocol
3255 A long standing bug in the mips64 remote protocol where by GDB
3256 expected certain 32 bit registers (ex SR) to be transfered as 32
3257 instead of 64 bits has been fixed.
3259 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3260 added to provide backward compatibility with older versions of GDB.
3262 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3264 The command ``set remotebinarydownload'' command has been replaced by
3265 ``set remote X-packet''. Other commands in ``set remote'' family
3266 include ``set remote P-packet''.
3268 * Breakpoint commands accept ranges.
3270 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3271 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3272 ``tracepoint passcount'' also accepts a range of tracepoints.
3274 * ``apropos'' command added.
3276 The ``apropos'' command searches through command names and
3277 documentation strings, printing out matches, making it much easier to
3278 try to find a command that does what you are looking for.
3282 A new machine oriented interface (MI) has been added to GDB. This
3283 interface is designed for debug environments running GDB as a separate
3284 process. This is part of the long term libGDB project. See the
3285 "GDB/MI" chapter of the GDB manual for further information. It can be
3286 enabled by configuring with:
3288 .../configure --enable-gdbmi
3290 *** Changes in GDB-4.18:
3292 * New native configurations
3294 HP-UX 10.20 hppa*-*-hpux10.20
3295 HP-UX 11.x hppa*-*-hpux11.0*
3296 M68K GNU/Linux m68*-*-linux*
3300 Fujitsu FR30 fr30-*-elf*
3301 Intel StrongARM strongarm-*-*
3302 Mitsubishi D30V d30v-*-*
3304 * OBSOLETE configurations
3306 Gould PowerNode, NP1 np1-*-*, pn-*-*
3308 Configurations that have been declared obsolete will be commented out,
3309 but the code will be left in place. If there is no activity to revive
3310 these configurations before the next release of GDB, the sources will
3311 be permanently REMOVED.
3315 As a compatibility experiment, GDB's source files buildsym.h and
3316 buildsym.c have been converted to pure standard C, no longer
3317 containing any K&R compatibility code. We believe that all systems in
3318 use today either come with a standard C compiler, or have a GCC port
3319 available. If this is not true, please report the affected
3320 configuration to bug-gdb@gnu.org immediately. See the README file for
3321 information about getting a standard C compiler if you don't have one
3326 GDB now uses readline 2.2.
3328 * set extension-language
3330 You can now control the mapping between filename extensions and source
3331 languages by using the `set extension-language' command. For instance,
3332 you can ask GDB to treat .c files as C++ by saying
3333 set extension-language .c c++
3334 The command `info extensions' lists all of the recognized extensions
3335 and their associated languages.
3337 * Setting processor type for PowerPC and RS/6000
3339 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3340 you can use the `set processor' command to specify what variant of the
3341 PowerPC family you are debugging. The command
3345 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3346 following PowerPC and RS6000 variants:
3348 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3349 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3351 403GC IBM PowerPC 403GC
3352 505 Motorola PowerPC 505
3353 860 Motorola PowerPC 860 or 850
3354 601 Motorola PowerPC 601
3355 602 Motorola PowerPC 602
3356 603 Motorola/IBM PowerPC 603 or 603e
3357 604 Motorola PowerPC 604 or 604e
3358 750 Motorola/IBM PowerPC 750 or 750
3360 At the moment, this command just tells GDB what to name the
3361 special-purpose processor registers. Since almost all the affected
3362 registers are inaccessible to user-level programs, this command is
3363 only useful for remote debugging in its present form.
3367 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3368 more extensive support for HP-UX. Added features include shared
3369 library support, kernel threads and hardware watchpoints for 11.00,
3370 support for HP's ANSI C and C++ compilers, and a compatibility mode
3371 for xdb and dbx commands.
3375 HP's donation includes the new concept of catchpoints, which is a
3376 generalization of the old catch command. On HP-UX, it is now possible
3377 to catch exec, fork, and vfork, as well as library loading.
3379 This means that the existing catch command has changed; its first
3380 argument now specifies the type of catch to be set up. See the
3381 output of "help catch" for a list of catchpoint types.
3383 * Debugging across forks
3385 On HP-UX, you can choose which process to debug when a fork() happens
3390 HP has donated a curses-based terminal user interface (TUI). To get
3391 it, build with --enable-tui. Although this can be enabled for any
3392 configuration, at present it only works for native HP debugging.
3394 * GDB remote protocol additions
3396 A new protocol packet 'X' that writes binary data is now available.
3397 Default behavior is to try 'X', then drop back to 'M' if the stub
3398 fails to respond. The settable variable `remotebinarydownload'
3399 allows explicit control over the use of 'X'.
3401 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3402 full 64-bit address. The command
3404 set remoteaddresssize 32
3406 can be used to revert to the old behaviour. For existing remote stubs
3407 the change should not be noticed, as the additional address information
3410 In order to assist in debugging stubs, you may use the maintenance
3411 command `packet' to send any text string to the stub. For instance,
3413 maint packet heythere
3415 sends the packet "$heythere#<checksum>". Note that it is very easy to
3416 disrupt a debugging session by sending the wrong packet at the wrong
3419 The compare-sections command allows you to compare section data on the
3420 target to what is in the executable file without uploading or
3421 downloading, by comparing CRC checksums.
3423 * Tracing can collect general expressions
3425 You may now collect general expressions at tracepoints. This requires
3426 further additions to the target-side stub; see tracepoint.c and
3427 doc/agentexpr.texi for further details.
3429 * mask-address variable for Mips
3431 For Mips targets, you may control the zeroing of the upper 32 bits of
3432 a 64-bit address by entering `set mask-address on'. This is mainly
3433 of interest to users of embedded R4xxx and R5xxx processors.
3435 * Higher serial baud rates
3437 GDB's serial code now allows you to specify baud rates 57600, 115200,
3438 230400, and 460800 baud. (Note that your host system may not be able
3439 to achieve all of these rates.)
3443 The i960 configuration now includes an initial implementation of a
3444 builtin simulator, contributed by Jim Wilson.
3447 *** Changes in GDB-4.17:
3449 * New native configurations
3451 Alpha GNU/Linux alpha*-*-linux*
3452 Unixware 2.x i[3456]86-unixware2*
3453 Irix 6.x mips*-sgi-irix6*
3454 PowerPC GNU/Linux powerpc-*-linux*
3455 PowerPC Solaris powerpcle-*-solaris*
3456 Sparc GNU/Linux sparc-*-linux*
3457 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3461 Argonaut Risc Chip (ARC) arc-*-*
3462 Hitachi H8/300S h8300*-*-*
3463 Matsushita MN10200 w/simulator mn10200-*-*
3464 Matsushita MN10300 w/simulator mn10300-*-*
3465 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3466 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3467 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3468 Mitsubishi D10V w/simulator d10v-*-*
3469 Mitsubishi M32R/D w/simulator m32r-*-elf*
3470 Tsqware Sparclet sparclet-*-*
3471 NEC V850 w/simulator v850-*-*
3473 * New debugging protocols
3475 ARM with RDI protocol arm*-*-*
3476 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3477 DDB and LSI variants of PMON protocol mips*-*-*
3478 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3479 PowerPC with SDS protocol powerpc{,le}-*-eabi
3480 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3484 All configurations can now understand and use the DWARF 2 debugging
3485 format. The choice is automatic, if the symbol file contains DWARF 2
3490 GDB now includes basic Java language support. This support is
3491 only useful with Java compilers that produce native machine code.
3493 * solib-absolute-prefix and solib-search-path
3495 For SunOS and SVR4 shared libraries, you may now set the prefix for
3496 loading absolute shared library symbol files, and the search path for
3497 locating non-absolute shared library symbol files.
3499 * Live range splitting
3501 GDB can now effectively debug code for which GCC has performed live
3502 range splitting as part of its optimization. See gdb/doc/LRS for
3503 more details on the expected format of the stabs information.
3507 GDB's support for the GNU Hurd, including thread debugging, has been
3508 updated to work with current versions of the Hurd.
3512 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3513 instruction set. ARM GDB automatically detects when Thumb
3514 instructions are in use, and adjusts disassembly and backtracing
3519 GDB's MIPS target configurations now handle the MIP16 16-bit
3524 GDB now includes support for overlays; if an executable has been
3525 linked such that multiple sections are based at the same address, GDB
3526 will decide which section to use for symbolic info. You can choose to
3527 control the decision manually, using overlay commands, or implement
3528 additional target-side support and use "overlay load-target" to bring
3529 in the overlay mapping. Do "help overlay" for more detail.
3533 The command "info symbol <address>" displays information about
3534 the symbol at the specified address.
3538 The standard remote protocol now includes an extension that allows
3539 asynchronous collection and display of trace data. This requires
3540 extensive support in the target-side debugging stub. Tracing mode
3541 includes a new interaction mode in GDB and new commands: see the
3542 file tracepoint.c for more details.
3546 Configurations for embedded MIPS now include a simulator contributed
3547 by Cygnus Solutions. The simulator supports the instruction sets
3548 of most MIPS variants.
3552 Sparc configurations may now include the ERC32 simulator contributed
3553 by the European Space Agency. The simulator is not built into
3554 Sparc targets by default; configure with --enable-sim to include it.
3558 For target configurations that may include multiple variants of a
3559 basic architecture (such as MIPS and SH), you may now set the
3560 architecture explicitly. "set arch" sets, "info arch" lists
3561 the possible architectures.
3563 *** Changes in GDB-4.16:
3565 * New native configurations
3567 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3568 M68K NetBSD m68k-*-netbsd*
3569 PowerPC AIX 4.x powerpc-*-aix*
3570 PowerPC MacOS powerpc-*-macos*
3571 PowerPC Windows NT powerpcle-*-cygwin32
3572 RS/6000 AIX 4.x rs6000-*-aix4*
3576 ARM with RDP protocol arm-*-*
3577 I960 with MON960 i960-*-coff
3578 MIPS VxWorks mips*-*-vxworks*
3579 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3580 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3582 Matra Sparclet sparclet-*-*
3586 The powerpc-eabi configuration now includes the PSIM simulator,
3587 contributed by Andrew Cagney, with assistance from Mike Meissner.
3588 PSIM is a very elaborate model of the PowerPC, including not only
3589 basic instruction set execution, but also details of execution unit
3590 performance and I/O hardware. See sim/ppc/README for more details.
3594 GDB now works with Solaris 2.5.
3596 * Windows 95/NT native
3598 GDB will now work as a native debugger on Windows 95 and Windows NT.
3599 To build it from source, you must use the "gnu-win32" environment,
3600 which uses a DLL to emulate enough of Unix to run the GNU tools.
3601 Further information, binaries, and sources are available at
3602 ftp.cygnus.com, under pub/gnu-win32.
3604 * dont-repeat command
3606 If a user-defined command includes the command `dont-repeat', then the
3607 command will not be repeated if the user just types return. This is
3608 useful if the command is time-consuming to run, so that accidental
3609 extra keystrokes don't run the same command many times.
3611 * Send break instead of ^C
3613 The standard remote protocol now includes an option to send a break
3614 rather than a ^C to the target in order to interrupt it. By default,
3615 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3617 * Remote protocol timeout
3619 The standard remote protocol includes a new variable `remotetimeout'
3620 that allows you to set the number of seconds before GDB gives up trying
3621 to read from the target. The default value is 2.
3623 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3625 By default GDB will automatically keep track of objects as they are
3626 loaded and unloaded by the dynamic linker. By using the command `set
3627 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3628 when shared library events occur, thus allowing you to set breakpoints
3629 in shared libraries which are explicitly loaded by the inferior.
3631 Note this feature does not work on hpux8. On hpux9 you must link
3632 /usr/lib/end.o into your program. This feature should work
3633 automatically on hpux10.
3635 * Irix 5.x hardware watchpoint support
3637 Irix 5 configurations now support the use of hardware watchpoints.
3639 * Mips protocol "SYN garbage limit"
3641 When debugging a Mips target using the `target mips' protocol, you
3642 may set the number of characters that GDB will ignore by setting
3643 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3644 every character. The default value is 1050.
3646 * Recording and replaying remote debug sessions
3648 If you set `remotelogfile' to the name of a file, gdb will write to it
3649 a recording of a remote debug session. This recording may then be
3650 replayed back to gdb using "gdbreplay". See gdbserver/README for
3651 details. This is useful when you have a problem with GDB while doing
3652 remote debugging; you can make a recording of the session and send it
3653 to someone else, who can then recreate the problem.
3655 * Speedups for remote debugging
3657 GDB includes speedups for downloading and stepping MIPS systems using
3658 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3659 and more efficient S-record downloading.
3661 * Memory use reductions and statistics collection
3663 GDB now uses less memory and reports statistics about memory usage.
3664 Try the `maint print statistics' command, for example.
3666 *** Changes in GDB-4.15:
3668 * Psymtabs for XCOFF
3670 The symbol reader for AIX GDB now uses partial symbol tables. This
3671 can greatly improve startup time, especially for large executables.
3673 * Remote targets use caching
3675 Remote targets now use a data cache to speed up communication with the
3676 remote side. The data cache could lead to incorrect results because
3677 it doesn't know about volatile variables, thus making it impossible to
3678 debug targets which use memory mapped I/O devices. `set remotecache
3679 off' turns the the data cache off.
3681 * Remote targets may have threads
3683 The standard remote protocol now includes support for multiple threads
3684 in the target system, using new protocol commands 'H' and 'T'. See
3685 gdb/remote.c for details.
3689 If GDB is configured with `--enable-netrom', then it will include
3690 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3691 acts as though it is a bank of ROM on the target board, but you can
3692 write into it over the network. GDB's support consists only of
3693 support for fast loading into the emulated ROM; to debug, you must use
3694 another protocol, such as standard remote protocol. The usual
3695 sequence is something like
3697 target nrom <netrom-hostname>
3699 target remote <netrom-hostname>:1235
3703 GDB now includes support for the Apple Macintosh, as a host only. It
3704 may be run as either an MPW tool or as a standalone application, and
3705 it can debug through the serial port. All the usual GDB commands are
3706 available, but to the target command, you must supply "serial" as the
3707 device type instead of "/dev/ttyXX". See mpw-README in the main
3708 directory for more information on how to build. The MPW configuration
3709 scripts */mpw-config.in support only a few targets, and only the
3710 mips-idt-ecoff target has been tested.
3714 GDB configuration now uses autoconf. This is not user-visible,
3715 but does simplify configuration and building.
3719 GDB now supports hpux10.
3721 *** Changes in GDB-4.14:
3723 * New native configurations
3725 x86 FreeBSD i[345]86-*-freebsd
3726 x86 NetBSD i[345]86-*-netbsd
3727 NS32k NetBSD ns32k-*-netbsd
3728 Sparc NetBSD sparc-*-netbsd
3732 A29K VxWorks a29k-*-vxworks
3733 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3734 CPU32 EST-300 emulator m68*-*-est*
3735 PowerPC ELF powerpc-*-elf
3738 * Alpha OSF/1 support for procfs
3740 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3741 possible to attach to running processes. As the mounting of the /proc
3742 filesystem is optional on the Alpha, GDB automatically determines
3743 the availability of /proc during startup. This can lead to problems
3744 if /proc is unmounted after GDB has been started.
3746 * Arguments to user-defined commands
3748 User commands may accept up to 10 arguments separated by whitespace.
3749 Arguments are accessed within the user command via $arg0..$arg9. A
3752 print $arg0 + $arg1 + $arg2
3754 To execute the command use:
3757 Defines the command "adder" which prints the sum of its three arguments.
3758 Note the arguments are text substitutions, so they may reference variables,
3759 use complex expressions, or even perform inferior function calls.
3761 * New `if' and `while' commands
3763 This makes it possible to write more sophisticated user-defined
3764 commands. Both commands take a single argument, which is the
3765 expression to evaluate, and must be followed by the commands to
3766 execute, one per line, if the expression is nonzero, the list being
3767 terminated by the word `end'. The `if' command list may include an
3768 `else' word, which causes the following commands to be executed only
3769 if the expression is zero.
3771 * Fortran source language mode
3773 GDB now includes partial support for Fortran 77. It will recognize
3774 Fortran programs and can evaluate a subset of Fortran expressions, but
3775 variables and functions may not be handled correctly. GDB will work
3776 with G77, but does not yet know much about symbols emitted by other
3779 * Better HPUX support
3781 Most debugging facilities now work on dynamic executables for HPPAs
3782 running hpux9 or later. You can attach to running dynamically linked
3783 processes, but by default the dynamic libraries will be read-only, so
3784 for instance you won't be able to put breakpoints in them. To change
3785 that behavior do the following before running the program:
3791 This will cause the libraries to be mapped private and read-write.
3792 To revert to the normal behavior, do this:
3798 You cannot set breakpoints or examine data in the library until after
3799 the library is loaded if the function/data symbols do not have
3802 GDB can now also read debug symbols produced by the HP C compiler on
3803 HPPAs (sorry, no C++, Fortran or 68k support).
3805 * Target byte order now dynamically selectable
3807 You can choose which byte order to use with a target system, via the
3808 commands "set endian big" and "set endian little", and you can see the
3809 current setting by using "show endian". You can also give the command
3810 "set endian auto", in which case GDB will use the byte order
3811 associated with the executable. Currently, only embedded MIPS
3812 configurations support dynamic selection of target byte order.
3814 * New DOS host serial code
3816 This version uses DPMI interrupts to handle buffered I/O, so you
3817 no longer need to run asynctsr when debugging boards connected to
3820 *** Changes in GDB-4.13:
3822 * New "complete" command
3824 This lists all the possible completions for the rest of the line, if it
3825 were to be given as a command itself. This is intended for use by emacs.
3827 * Trailing space optional in prompt
3829 "set prompt" no longer adds a space for you after the prompt you set. This
3830 allows you to set a prompt which ends in a space or one that does not.
3832 * Breakpoint hit counts
3834 "info break" now displays a count of the number of times the breakpoint
3835 has been hit. This is especially useful in conjunction with "ignore"; you
3836 can ignore a large number of breakpoint hits, look at the breakpoint info
3837 to see how many times the breakpoint was hit, then run again, ignoring one
3838 less than that number, and this will get you quickly to the last hit of
3841 * Ability to stop printing at NULL character
3843 "set print null-stop" will cause GDB to stop printing the characters of
3844 an array when the first NULL is encountered. This is useful when large
3845 arrays actually contain only short strings.
3847 * Shared library breakpoints
3849 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3850 breakpoints in shared libraries before the executable is run.
3852 * Hardware watchpoints
3854 There is a new hardware breakpoint for the watch command for sparclite
3855 targets. See gdb/sparclite/hw_breakpoint.note.
3857 Hardware watchpoints are also now supported under GNU/Linux.
3861 Annotations have been added. These are for use with graphical interfaces,
3862 and are still experimental. Currently only gdba.el uses these.
3864 * Improved Irix 5 support
3866 GDB now works properly with Irix 5.2.
3868 * Improved HPPA support
3870 GDB now works properly with the latest GCC and GAS.
3872 * New native configurations
3874 Sequent PTX4 i[34]86-sequent-ptx4
3875 HPPA running OSF/1 hppa*-*-osf*
3876 Atari TT running SVR4 m68*-*-sysv4*
3877 RS/6000 LynxOS rs6000-*-lynxos*
3881 OS/9000 i[34]86-*-os9k
3882 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3885 * Hitachi SH7000 and E7000-PC ICE support
3887 There is now support for communicating with the Hitachi E7000-PC ICE.
3888 This is available automatically when GDB is configured for the SH.
3892 As usual, a variety of small fixes and improvements, both generic
3893 and configuration-specific. See the ChangeLog for more detail.
3895 *** Changes in GDB-4.12:
3897 * Irix 5 is now supported
3901 GDB-4.12 on the HPPA has a number of changes which make it unable
3902 to debug the output from the currently released versions of GCC and
3903 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3904 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3905 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3908 *** Changes in GDB-4.11:
3910 * User visible changes:
3914 The "set remotedebug" option is now consistent between the mips remote
3915 target, remote targets using the gdb-specific protocol, UDI (AMD's
3916 debug protocol for the 29k) and the 88k bug monitor. It is now an
3917 integer specifying a debug level (normally 0 or 1, but 2 means more
3918 debugging info for the mips target).
3920 * DEC Alpha native support
3922 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3923 debug info, but GDB works fairly well with the DEC compiler and should
3924 work with a future GCC release. See the README file for a few
3925 Alpha-specific notes.
3927 * Preliminary thread implementation
3929 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3931 * LynxOS native and target support for 386
3933 This release has been hosted on LynxOS 2.2, and also can be configured
3934 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3937 * Improvements in C++ mangling/demangling.
3939 This release has much better g++ debugging, specifically in name
3940 mangling/demangling, virtual function calls, print virtual table,
3941 call methods, ...etc.
3943 *** Changes in GDB-4.10:
3945 * User visible changes:
3947 Remote debugging using the GDB-specific (`target remote') protocol now
3948 supports the `load' command. This is only useful if you have some
3949 other way of getting the stub to the target system, and you can put it
3950 somewhere in memory where it won't get clobbered by the download.
3952 Filename completion now works.
3954 When run under emacs mode, the "info line" command now causes the
3955 arrow to point to the line specified. Also, "info line" prints
3956 addresses in symbolic form (as well as hex).
3958 All vxworks based targets now support a user settable option, called
3959 vxworks-timeout. This option represents the number of seconds gdb
3960 should wait for responses to rpc's. You might want to use this if
3961 your vxworks target is, perhaps, a slow software simulator or happens
3962 to be on the far side of a thin network line.
3966 This release contains support for using a DEC alpha as a GDB host for
3967 cross debugging. Native alpha debugging is not supported yet.
3970 *** Changes in GDB-4.9:
3974 This is the first GDB release which is accompanied by a matching testsuite.
3975 The testsuite requires installation of dejagnu, which should be available
3976 via ftp from most sites that carry GNU software.
3980 'Cfront' style demangling has had its name changed to 'ARM' style, to
3981 emphasize that it was written from the specifications in the C++ Annotated
3982 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3983 disclaimers, it still generated too much confusion with users attempting to
3984 use gdb with AT&T cfront.
3988 GDB now uses a standard remote interface to a simulator library.
3989 So far, the library contains simulators for the Zilog Z8001/2, the
3990 Hitachi H8/300, H8/500 and Super-H.
3992 * New targets supported
3994 H8/300 simulator h8300-hitachi-hms or h8300hms
3995 H8/500 simulator h8500-hitachi-hms or h8500hms
3996 SH simulator sh-hitachi-hms or sh
3997 Z8000 simulator z8k-zilog-none or z8ksim
3998 IDT MIPS board over serial line mips-idt-ecoff
4000 Cross-debugging to GO32 targets is supported. It requires a custom
4001 version of the i386-stub.c module which is integrated with the
4002 GO32 memory extender.
4004 * New remote protocols
4006 MIPS remote debugging protocol.
4008 * New source languages supported
4010 This version includes preliminary support for Chill, a Pascal like language
4011 used by telecommunications companies. Chill support is also being integrated
4012 into the GNU compiler, but we don't know when it will be publically available.
4015 *** Changes in GDB-4.8:
4017 * HP Precision Architecture supported
4019 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4020 version of this support was available as a set of patches from the
4021 University of Utah. GDB does not support debugging of programs
4022 compiled with the HP compiler, because HP will not document their file
4023 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4024 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4026 Many problems in the preliminary version have been fixed.
4028 * Faster and better demangling
4030 We have improved template demangling and fixed numerous bugs in the GNU style
4031 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4032 character types (wchar_t) are now supported. Demangling of each symbol is now
4033 only done once, and is cached when the symbol table for a file is read in.
4034 This results in a small increase in memory usage for C programs, a moderate
4035 increase in memory usage for C++ programs, and a fantastic speedup in
4038 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4039 from the specifications in the Annotated Reference Manual, which AT&T's
4040 compiler does not actually implement.
4042 * G++ multiple inheritance compiler problem
4044 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4045 inheritance lattices was reworked to properly discover ambiguities. We
4046 recently found an example which causes this new algorithm to fail in a
4047 very subtle way, producing bad debug information for those classes.
4048 The file 'gcc.patch' (in this directory) can be applied to gcc to
4049 circumvent the problem. A future GCC release will contain a complete
4052 The previous G++ debug info problem (mentioned below for the gdb-4.7
4053 release) is fixed in gcc version 2.3.2.
4055 * Improved configure script
4057 The `configure' script will now attempt to guess your system type if
4058 you don't supply a host system type. The old scheme of supplying a
4059 host system triplet is preferable over using this. All the magic is
4060 done in the new `config.guess' script. Examine it for details.
4062 We have also brought our configure script much more in line with the FSF's
4063 version. It now supports the --with-xxx options. In particular,
4064 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4065 The resulting GDB will not be able to read arbitrary object file formats --
4066 only the format ``expected'' to be used on the configured target system.
4067 We hope to make this the default in a future release.
4069 * Documentation improvements
4071 There's new internal documentation on how to modify GDB, and how to
4072 produce clean changes to the code. We implore people to read it
4073 before submitting changes.
4075 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4076 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4077 `info' files are also provided. To build `info' files from scratch,
4078 you will need the latest `makeinfo' release, which will be available in
4079 a future texinfo-X.Y release.
4081 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4082 We're not sure exactly which versions have this problem, but it has
4083 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4084 or better. If that isn't possible, there is a patch in
4085 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4086 around this problem.
4090 GDB now supports array constants that can be used in expressions typed in by
4091 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4092 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4095 The new directory `gdb/sparclite' contains a program that demonstrates
4096 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4098 * New native hosts supported
4100 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4101 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4103 * New targets supported
4105 AMD 29k family via UDI a29k-amd-udi or udi29k
4107 * New file formats supported
4109 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4110 HPUX core files, and SCO 3.2v2 core files.
4114 Attaching to processes now works again; thanks for the many bug reports.
4116 We have also stomped on a bunch of core dumps caused by
4117 printf_filtered("%s") problems.
4119 We eliminated a copyright problem on the rpc and ptrace header files
4120 for VxWorks, which was discovered at the last minute during the 4.7
4121 release. You should now be able to build a VxWorks GDB.
4123 You can now interrupt gdb while an attached process is running. This
4124 will cause the attached process to stop, and give control back to GDB.
4126 We fixed problems caused by using too many file descriptors
4127 for reading symbols from object files and libraries. This was
4128 especially a problem for programs that used many (~100) shared
4131 The `step' command now only enters a subroutine if there is line number
4132 information for the subroutine. Otherwise it acts like the `next'
4133 command. Previously, `step' would enter subroutines if there was
4134 any debugging information about the routine. This avoids problems
4135 when using `cc -g1' on MIPS machines.
4137 * Internal improvements
4139 GDB's internal interfaces have been improved to make it easier to support
4140 debugging of multiple languages in the future.
4142 GDB now uses a common structure for symbol information internally.
4143 Minimal symbols (derived from linkage symbols in object files), partial
4144 symbols (from a quick scan of debug information), and full symbols
4145 contain a common subset of information, making it easier to write
4146 shared code that handles any of them.
4148 * New command line options
4150 We now accept --silent as an alias for --quiet.
4154 The memory-mapped-malloc library is now licensed under the GNU Library
4155 General Public License.
4157 *** Changes in GDB-4.7:
4159 * Host/native/target split
4161 GDB has had some major internal surgery to untangle the support for
4162 hosts and remote targets. Now, when you configure GDB for a remote
4163 target, it will no longer load in all of the support for debugging
4164 local programs on the host. When fully completed and tested, this will
4165 ensure that arbitrary host/target combinations are possible.
4167 The primary conceptual shift is to separate the non-portable code in
4168 GDB into three categories. Host specific code is required any time GDB
4169 is compiled on that host, regardless of the target. Target specific
4170 code relates to the peculiarities of the target, but can be compiled on
4171 any host. Native specific code is everything else: it can only be
4172 built when the host and target are the same system. Child process
4173 handling and core file support are two common `native' examples.
4175 GDB's use of /proc for controlling Unix child processes is now cleaner.
4176 It has been split out into a single module under the `target_ops' vector,
4177 plus two native-dependent functions for each system that uses /proc.
4179 * New hosts supported
4181 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4182 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4183 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4185 * New targets supported
4187 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4188 68030 and CPU32 m68030-*-*, m68332-*-*
4190 * New native hosts supported
4192 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4193 (386bsd is not well tested yet)
4194 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4196 * New file formats supported
4198 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4199 supports reading of `a.out.adobe' object files, which are an a.out
4200 format extended with minimal information about multiple sections.
4204 `show copying' is the same as the old `info copying'.
4205 `show warranty' is the same as `info warrantee'.
4206 These were renamed for consistency. The old commands continue to work.
4208 `info handle' is a new alias for `info signals'.
4210 You can now define pre-command hooks, which attach arbitrary command
4211 scripts to any command. The commands in the hook will be executed
4212 prior to the user's command. You can also create a hook which will be
4213 executed whenever the program stops. See gdb.texinfo.
4217 We now deal with Cfront style name mangling, and can even extract type
4218 info from mangled symbols. GDB can automatically figure out which
4219 symbol mangling style your C++ compiler uses.
4221 Calling of methods and virtual functions has been improved as well.
4225 The crash that occured when debugging Sun Ansi-C compiled binaries is
4226 fixed. This was due to mishandling of the extra N_SO stabs output
4229 We also finally got Ultrix 4.2 running in house, and fixed core file
4230 support, with help from a dozen people on the net.
4232 John M. Farrell discovered that the reason that single-stepping was so
4233 slow on all of the Mips based platforms (primarily SGI and DEC) was
4234 that we were trying to demangle and lookup a symbol used for internal
4235 purposes on every instruction that was being stepped through. Changing
4236 the name of that symbol so that it couldn't be mistaken for a C++
4237 mangled symbol sped things up a great deal.
4239 Rich Pixley sped up symbol lookups in general by getting much smarter
4240 about when C++ symbol mangling is necessary. This should make symbol
4241 completion (TAB on the command line) much faster. It's not as fast as
4242 we'd like, but it's significantly faster than gdb-4.6.
4246 A new user controllable variable 'call_scratch_address' can
4247 specify the location of a scratch area to be used when GDB
4248 calls a function in the target. This is necessary because the
4249 usual method of putting the scratch area on the stack does not work
4250 in systems that have separate instruction and data spaces.
4252 We integrated changes to support the 29k UDI (Universal Debugger
4253 Interface), but discovered at the last minute that we didn't have all
4254 of the appropriate copyright paperwork. We are working with AMD to
4255 resolve this, and hope to have it available soon.
4259 We have sped up the remote serial line protocol, especially for targets
4260 with lots of registers. It now supports a new `expedited status' ('T')
4261 message which can be used in place of the existing 'S' status message.
4262 This allows the remote stub to send only the registers that GDB
4263 needs to make a quick decision about single-stepping or conditional
4264 breakpoints, eliminating the need to fetch the entire register set for
4265 each instruction being stepped through.
4267 The GDB remote serial protocol now implements a write-through cache for
4268 registers, only re-reading the registers if the target has run.
4270 There is also a new remote serial stub for SPARC processors. You can
4271 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4272 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4273 processor with a serial port.
4277 Configure.in files have become much easier to read and modify. A new
4278 `table driven' format makes it more obvious what configurations are
4279 supported, and what files each one uses.
4283 There is a new opcodes library which will eventually contain all of the
4284 disassembly routines and opcode tables. At present, it only contains
4285 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4286 disassembler (binutils/objdump) to share these routines.
4288 The libiberty library is now copylefted under the GNU Library General
4289 Public License. This allows more liberal use, and was done so libg++
4290 can use it. This makes no difference to GDB, since the Library License
4291 grants all the rights from the General Public License.
4295 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4296 reference to the stabs symbol info used by the debugger. It is (as far
4297 as we know) the only published document on this fascinating topic. We
4298 encourage you to read it, compare it to the stabs information on your
4299 system, and send improvements on the document in general (to
4300 bug-gdb@prep.ai.mit.edu).
4302 And, of course, many bugs have been fixed.
4305 *** Changes in GDB-4.6:
4307 * Better support for C++ function names
4309 GDB now accepts as input the "demangled form" of C++ overloaded function
4310 names and member function names, and can do command completion on such names
4311 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4312 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4313 Make use of command completion, it is your friend.
4315 GDB also now accepts a variety of C++ mangled symbol formats. They are
4316 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4317 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4318 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4319 for the list of formats.
4321 * G++ symbol mangling problem
4323 Recent versions of gcc have a bug in how they emit debugging information for
4324 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4325 directory) can be applied to gcc to fix the problem. Alternatively, if you
4326 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4327 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4328 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4331 * New 'maintenance' command
4333 All of the commands related to hacking GDB internals have been moved out of
4334 the main command set, and now live behind the 'maintenance' command. This
4335 can also be abbreviated as 'mt'. The following changes were made:
4337 dump-me -> maintenance dump-me
4338 info all-breakpoints -> maintenance info breakpoints
4339 printmsyms -> maintenance print msyms
4340 printobjfiles -> maintenance print objfiles
4341 printpsyms -> maintenance print psymbols
4342 printsyms -> maintenance print symbols
4344 The following commands are new:
4346 maintenance demangle Call internal GDB demangler routine to
4347 demangle a C++ link name and prints the result.
4348 maintenance print type Print a type chain for a given symbol
4350 * Change to .gdbinit file processing
4352 We now read the $HOME/.gdbinit file before processing the argv arguments
4353 (e.g. reading symbol files or core files). This allows global parameters to
4354 be set, which will apply during the symbol reading. The ./.gdbinit is still
4355 read after argv processing.
4357 * New hosts supported
4359 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4361 GNU/Linux support i386-unknown-linux or linux
4363 We are also including code to support the HP/PA running BSD and HPUX. This
4364 is almost guaranteed not to work, as we didn't have time to test or build it
4365 for this release. We are including it so that the more adventurous (or
4366 masochistic) of you can play with it. We also had major problems with the
4367 fact that the compiler that we got from HP doesn't support the -g option.
4370 * New targets supported
4372 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4374 * More smarts about finding #include files
4376 GDB now remembers the compilation directory for all include files, and for
4377 all files from which C is generated (like yacc and lex sources). This
4378 greatly improves GDB's ability to find yacc/lex sources, and include files,
4379 especially if you are debugging your program from a directory different from
4380 the one that contains your sources.
4382 We also fixed a bug which caused difficulty with listing and setting
4383 breakpoints in include files which contain C code. (In the past, you had to
4384 try twice in order to list an include file that you hadn't looked at before.)
4386 * Interesting infernals change
4388 GDB now deals with arbitrary numbers of sections, where the symbols for each
4389 section must be relocated relative to that section's landing place in the
4390 target's address space. This work was needed to support ELF with embedded
4391 stabs used by Solaris-2.0.
4393 * Bug fixes (of course!)
4395 There have been loads of fixes for the following things:
4396 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4397 i960, stabs, DOS(GO32), procfs, etc...
4399 See the ChangeLog for details.
4401 *** Changes in GDB-4.5:
4403 * New machines supported (host and target)
4405 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4407 SGI Irix-4.x mips-sgi-irix4 or iris4
4409 * New malloc package
4411 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4412 Mmalloc is capable of handling mutiple heaps of memory. It is also
4413 capable of saving a heap to a file, and then mapping it back in later.
4414 This can be used to greatly speedup the startup of GDB by using a
4415 pre-parsed symbol table which lives in a mmalloc managed heap. For
4416 more details, please read mmalloc/mmalloc.texi.
4420 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4421 'help info proc' for details.
4423 * MIPS ecoff symbol table format
4425 The code that reads MIPS symbol table format is now supported on all hosts.
4426 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4429 * File name changes for MS-DOS
4431 Many files in the config directories have been renamed to make it easier to
4432 support GDB on MS-DOSe systems (which have very restrictive file name
4433 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4434 environment) is close to working but has some remaining problems. Note
4435 that debugging of DOS programs is not supported, due to limitations
4436 in the ``operating system'', but it can be used to host cross-debugging.
4438 * Cross byte order fixes
4440 Many fixes have been made to support cross debugging of Sparc and MIPS
4441 targets from hosts whose byte order differs.
4443 * New -mapped and -readnow options
4445 If memory-mapped files are available on your system through the 'mmap'
4446 system call, you can use the -mapped option on the `file' or
4447 `symbol-file' commands to cause GDB to write the symbols from your
4448 program into a reusable file. If the program you are debugging is
4449 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4450 Future GDB debugging sessions will notice the presence of this file,
4451 and will quickly map in symbol information from it, rather than reading
4452 the symbol table from the executable program. Using the '-mapped'
4453 option in a GDB `file' or `symbol-file' command has the same effect as
4454 starting GDB with the '-mapped' command-line option.
4456 You can cause GDB to read the entire symbol table immediately by using
4457 the '-readnow' option with any of the commands that load symbol table
4458 information (or on the GDB command line). This makes the command
4459 slower, but makes future operations faster.
4461 The -mapped and -readnow options are typically combined in order to
4462 build a `fred.syms' file that contains complete symbol information.
4463 A simple GDB invocation to do nothing but build a `.syms' file for future
4466 gdb -batch -nx -mapped -readnow programname
4468 The `.syms' file is specific to the host machine on which GDB is run.
4469 It holds an exact image of GDB's internal symbol table. It cannot be
4470 shared across multiple host platforms.
4472 * longjmp() handling
4474 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4475 siglongjmp() without losing control. This feature has not yet been ported to
4476 all systems. It currently works on many 386 platforms, all MIPS-based
4477 platforms (SGI, DECstation, etc), and Sun3/4.
4481 Preliminary work has been put in to support the new Solaris OS from Sun. At
4482 this time, it can control and debug processes, but it is not capable of
4487 As always, many many bug fixes. The major areas were with g++, and mipsread.
4488 People using the MIPS-based platforms should experience fewer mysterious
4489 crashes and trashed symbol tables.
4491 *** Changes in GDB-4.4:
4493 * New machines supported (host and target)
4495 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4497 BSD Reno on Vax vax-dec-bsd
4498 Ultrix on Vax vax-dec-ultrix
4500 * New machines supported (target)
4502 AMD 29000 embedded, using EBMON a29k-none-none
4506 GDB continues to improve its handling of C++. `References' work better.
4507 The demangler has also been improved, and now deals with symbols mangled as
4508 per the Annotated C++ Reference Guide.
4510 GDB also now handles `stabs' symbol information embedded in MIPS
4511 `ecoff' symbol tables. Since the ecoff format was not easily
4512 extensible to handle new languages such as C++, this appeared to be a
4513 good way to put C++ debugging info into MIPS binaries. This option
4514 will be supported in the GNU C compiler, version 2, when it is
4517 * New features for SVR4
4519 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4520 shared libraries. Debugging dynamically linked programs should present
4521 only minor differences from debugging statically linked programs.
4523 The `info proc' command will print out information about any process
4524 on an SVR4 system (including the one you are debugging). At the moment,
4525 it prints the address mappings of the process.
4527 If you bring up GDB on another SVR4 system, please send mail to
4528 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4530 * Better dynamic linking support in SunOS
4532 Reading symbols from shared libraries which contain debugging symbols
4533 now works properly. However, there remain issues such as automatic
4534 skipping of `transfer vector' code during function calls, which
4535 make it harder to debug code in a shared library, than to debug the
4536 same code linked statically.
4540 GDB is now using the latest `getopt' routines from the FSF. This
4541 version accepts the -- prefix for options with long names. GDB will
4542 continue to accept the old forms (-option and +option) as well.
4543 Various single letter abbreviations for options have been explicity
4544 added to the option table so that they won't get overshadowed in the
4545 future by other options that begin with the same letter.
4549 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4550 Many assorted bugs have been handled. Many more remain to be handled.
4551 See the various ChangeLog files (primarily in gdb and bfd) for details.
4554 *** Changes in GDB-4.3:
4556 * New machines supported (host and target)
4558 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4559 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4560 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4562 * Almost SCO Unix support
4564 We had hoped to support:
4565 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4566 (except for core file support), but we discovered very late in the release
4567 that it has problems with process groups that render gdb unusable. Sorry
4568 about that. I encourage people to fix it and post the fixes.
4570 * Preliminary ELF and DWARF support
4572 GDB can read ELF object files on System V Release 4, and can handle
4573 debugging records for C, in DWARF format, in ELF files. This support
4574 is preliminary. If you bring up GDB on another SVR4 system, please
4575 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4580 GDB now uses the latest `readline' library. One user-visible change
4581 is that two tabs will list possible command completions, which previously
4582 required typing M-? (meta-question mark, or ESC ?).
4586 The `stepi' bug that many of you noticed has been squashed.
4587 Many bugs in C++ have been handled. Many more remain to be handled.
4588 See the various ChangeLog files (primarily in gdb and bfd) for details.
4590 * State of the MIPS world (in case you wondered):
4592 GDB can understand the symbol tables emitted by the compilers
4593 supplied by most vendors of MIPS-based machines, including DEC. These
4594 symbol tables are in a format that essentially nobody else uses.
4596 Some versions of gcc come with an assembler post-processor called
4597 mips-tfile. This program is required if you want to do source-level
4598 debugging of gcc-compiled programs. I believe FSF does not ship
4599 mips-tfile with gcc version 1, but it will eventually come with gcc
4602 Debugging of g++ output remains a problem. g++ version 1.xx does not
4603 really support it at all. (If you're lucky, you should be able to get
4604 line numbers and stack traces to work, but no parameters or local
4605 variables.) With some work it should be possible to improve the
4608 When gcc version 2 is released, you will have somewhat better luck.
4609 However, even then you will get confusing results for inheritance and
4612 We will eventually provide full debugging of g++ output on
4613 DECstations. This will probably involve some kind of stabs-in-ecoff
4614 encapulation, but the details have not been worked out yet.
4617 *** Changes in GDB-4.2:
4619 * Improved configuration
4621 Only one copy of `configure' exists now, and it is not self-modifying.
4622 Porting BFD is simpler.
4626 The `step' and `next' commands now only stop at the first instruction
4627 of a source line. This prevents the multiple stops that used to occur
4628 in switch statements, for-loops, etc. `Step' continues to stop if a
4629 function that has debugging information is called within the line.
4633 Lots of small bugs fixed. More remain.
4635 * New host supported (not target)
4637 Intel 386 PC clone running Mach i386-none-mach
4640 *** Changes in GDB-4.1:
4642 * Multiple source language support
4644 GDB now has internal scaffolding to handle several source languages.
4645 It determines the type of each source file from its filename extension,
4646 and will switch expression parsing and number formatting to match the
4647 language of the function in the currently selected stack frame.
4648 You can also specifically set the language to be used, with
4649 `set language c' or `set language modula-2'.
4653 GDB now has preliminary support for the GNU Modula-2 compiler,
4654 currently under development at the State University of New York at
4655 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4656 continue through the fall of 1991 and into 1992.
4658 Other Modula-2 compilers are currently not supported, and attempting to
4659 debug programs compiled with them will likely result in an error as the
4660 symbol table is read. Feel free to work on it, though!
4662 There are hooks in GDB for strict type checking and range checking,
4663 in the `Modula-2 philosophy', but they do not currently work.
4667 GDB can now write to executable and core files (e.g. patch
4668 a variable's value). You must turn this switch on, specify
4669 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4670 by assigning a new value to a variable. Modifications take
4673 * Automatic SunOS shared library reading
4675 When you run your program, GDB automatically determines where its
4676 shared libraries (if any) have been loaded, and reads their symbols.
4677 The `share' command is no longer needed. This also works when
4678 examining core files.
4682 You can specify the number of lines that the `list' command shows.
4685 * New machines supported (host and target)
4687 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4688 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4689 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4691 * New hosts supported (not targets)
4693 IBM RT/PC: romp-ibm-aix or rtpc
4695 * New targets supported (not hosts)
4697 AMD 29000 embedded with COFF a29k-none-coff
4698 AMD 29000 embedded with a.out a29k-none-aout
4699 Ultracomputer remote kernel debug a29k-nyu-kern
4701 * New remote interfaces
4707 *** Changes in GDB-4.0:
4711 Wide output is wrapped at good places to make the output more readable.
4713 Gdb now supports cross-debugging from a host machine of one type to a
4714 target machine of another type. Communication with the target system
4715 is over serial lines. The ``target'' command handles connecting to the
4716 remote system; the ``load'' command will download a program into the
4717 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4718 also supports debugging of realtime processes running under VxWorks,
4719 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4720 stub on the target system.
4722 New CPUs supported include the AMD 29000 and Intel 960.
4724 GDB now reads object files and symbol tables via a ``binary file''
4725 library, which allows a single copy of GDB to debug programs of multiple
4726 object file types such as a.out and coff.
4728 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4729 refcard.dvi and refcard.ps are available to format it).
4732 * Control-Variable user interface simplified
4734 All variables that control the operation of the debugger can be set
4735 by the ``set'' command, and displayed by the ``show'' command.
4737 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4738 ``Show prompt'' produces the response:
4739 Gdb's prompt is new-gdb=>.
4741 What follows are the NEW set commands. The command ``help set'' will
4742 print a complete list of old and new set commands. ``help set FOO''
4743 will give a longer description of the variable FOO. ``show'' will show
4744 all of the variable descriptions and their current settings.
4746 confirm on/off: Enables warning questions for operations that are
4747 hard to recover from, e.g. rerunning the program while
4748 it is already running. Default is ON.
4750 editing on/off: Enables EMACS style command line editing
4751 of input. Previous lines can be recalled with
4752 control-P, the current line can be edited with control-B,
4753 you can search for commands with control-R, etc.
4756 history filename NAME: NAME is where the gdb command history
4757 will be stored. The default is .gdb_history,
4758 or the value of the environment variable
4761 history size N: The size, in commands, of the command history. The
4762 default is 256, or the value of the environment variable
4765 history save on/off: If this value is set to ON, the history file will
4766 be saved after exiting gdb. If set to OFF, the
4767 file will not be saved. The default is OFF.
4769 history expansion on/off: If this value is set to ON, then csh-like
4770 history expansion will be performed on
4771 command line input. The default is OFF.
4773 radix N: Sets the default radix for input and output. It can be set
4774 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4775 in the current radix, so "set radix 10" is always a no-op.
4777 height N: This integer value is the number of lines on a page. Default
4778 is 24, the current `stty rows'' setting, or the ``li#''
4779 setting from the termcap entry matching the environment
4782 width N: This integer value is the number of characters on a line.
4783 Default is 80, the current `stty cols'' setting, or the ``co#''
4784 setting from the termcap entry matching the environment
4787 Note: ``set screensize'' is obsolete. Use ``set height'' and
4788 ``set width'' instead.
4790 print address on/off: Print memory addresses in various command displays,
4791 such as stack traces and structure values. Gdb looks
4792 more ``symbolic'' if you turn this off; it looks more
4793 ``machine level'' with it on. Default is ON.
4795 print array on/off: Prettyprint arrays. New convenient format! Default
4798 print demangle on/off: Print C++ symbols in "source" form if on,
4801 print asm-demangle on/off: Same, for assembler level printouts
4804 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4807 * Support for Epoch Environment.
4809 The epoch environment is a version of Emacs v18 with windowing. One
4810 new command, ``inspect'', is identical to ``print'', except that if you
4811 are running in the epoch environment, the value is printed in its own
4815 * Support for Shared Libraries
4817 GDB can now debug programs and core files that use SunOS shared libraries.
4818 Symbols from a shared library cannot be referenced
4819 before the shared library has been linked with the program (this
4820 happens after you type ``run'' and before the function main() is entered).
4821 At any time after this linking (including when examining core files
4822 from dynamically linked programs), gdb reads the symbols from each
4823 shared library when you type the ``sharedlibrary'' command.
4824 It can be abbreviated ``share''.
4826 sharedlibrary REGEXP: Load shared object library symbols for files
4827 matching a unix regular expression. No argument
4828 indicates to load symbols for all shared libraries.
4830 info sharedlibrary: Status of loaded shared libraries.
4835 A watchpoint stops execution of a program whenever the value of an
4836 expression changes. Checking for this slows down execution
4837 tremendously whenever you are in the scope of the expression, but is
4838 quite useful for catching tough ``bit-spreader'' or pointer misuse
4839 problems. Some machines such as the 386 have hardware for doing this
4840 more quickly, and future versions of gdb will use this hardware.
4842 watch EXP: Set a watchpoint (breakpoint) for an expression.
4844 info watchpoints: Information about your watchpoints.
4846 delete N: Deletes watchpoint number N (same as breakpoints).
4847 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4848 enable N: Re-enables watchpoint number N (same as breakpoints).
4851 * C++ multiple inheritance
4853 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4856 * C++ exception handling
4858 Gdb now supports limited C++ exception handling. Besides the existing
4859 ability to breakpoint on an exception handler, gdb can breakpoint on
4860 the raising of an exception (before the stack is peeled back to the
4863 catch FOO: If there is a FOO exception handler in the dynamic scope,
4864 set a breakpoint to catch exceptions which may be raised there.
4865 Multiple exceptions (``catch foo bar baz'') may be caught.
4867 info catch: Lists all exceptions which may be caught in the
4868 current stack frame.
4871 * Minor command changes
4873 The command ``call func (arg, arg, ...)'' now acts like the print
4874 command, except it does not print or save a value if the function's result
4875 is void. This is similar to dbx usage.
4877 The ``up'' and ``down'' commands now always print the frame they end up
4878 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4879 frames without printing.
4881 * New directory command
4883 'dir' now adds directories to the FRONT of the source search path.
4884 The path starts off empty. Source files that contain debug information
4885 about the directory in which they were compiled can be found even
4886 with an empty path; Sun CC and GCC include this information. If GDB can't
4887 find your source file in the current directory, type "dir .".
4889 * Configuring GDB for compilation
4891 For normal use, type ``./configure host''. See README or gdb.texinfo
4894 GDB now handles cross debugging. If you are remotely debugging between
4895 two different machines, type ``./configure host -target=targ''.
4896 Host is the machine where GDB will run; targ is the machine
4897 where the program that you are debugging will run.