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 ("host") or by
106 GDBserver ("target"). Default option "auto" chooses the most efficient
108 This option can improve debugger efficiency depending on the speed of the
113 z0/z1 conditional breakpoints extension
115 The z0/z1 breakpoint insertion packets have been extended to carry
116 a list of conditional expressions over to the remote stub depending on the
117 condition evaluation mode. The use of this extension can be controlled
118 via the "set remote conditional-breakpoints-packet" command.
122 Specify the signals which the remote stub may pass to the debugged
123 program without GDB involvement.
125 * New command line options
127 --init-command=FILE, -ix Like --command, -x but execute it
128 before loading inferior.
129 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
130 execute it before loading inferior.
132 *** Changes in GDB 7.4
134 * GDB now handles ambiguous linespecs more consistently; the existing
135 FILE:LINE support has been expanded to other types of linespecs. A
136 breakpoint will now be set on all matching locations in all
137 inferiors, and locations will be added or removed according to
140 * GDB now allows you to skip uninteresting functions and files when
141 stepping with the "skip function" and "skip file" commands.
143 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
144 and "show remote hardware-watchpoint-length-limit". These allows to
145 set or show the maximum length limit (in bytes) of a remote
146 target hardware watchpoint.
148 This allows e.g. to use "unlimited" hardware watchpoints with the
149 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
150 watchpoints are slower than real hardware watchpoints but are
151 significantly faster than gdb software watchpoints.
155 ** The register_pretty_printer function in module gdb.printing now takes
156 an optional `replace' argument. If True, the new printer replaces any
159 ** The "maint set python print-stack on|off" command has been
160 deprecated and will be deleted in GDB 7.5.
161 A new command: "set python print-stack none|full|message" has
162 replaced it. Additionally, the default for "print-stack" is
163 now "message", which just prints the error message without
166 ** A prompt substitution hook (prompt_hook) is now available to the
169 ** A new Python module, gdb.prompt has been added to the GDB Python
170 modules library. This module provides functionality for
171 escape sequences in prompts (used by set/show
172 extended-prompt). These escape sequences are replaced by their
175 ** Python commands and convenience-functions located in
176 'data-directory'/python/gdb/command and
177 'data-directory'/python/gdb/function are now automatically loaded
180 ** Blocks now provide four new attributes. global_block and
181 static_block will return the global and static blocks
182 respectively. is_static and is_global are boolean attributes
183 that indicate if the block is one of those two types.
185 ** Symbols now provide the "type" attribute, the type of the symbol.
187 ** The "gdb.breakpoint" function has been deprecated in favor of
190 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
191 of a function. This class is based on the "finish" command
192 available in the CLI.
194 ** Type objects for struct and union types now allow access to
195 the fields using standard Python dictionary (mapping) methods.
196 For example, "some_type['myfield']" now works, as does
199 ** A new event "gdb.new_objfile" has been added, triggered by loading a
202 ** A new function, "deep_items" has been added to the gdb.types
203 module in the GDB Python modules library. This function returns
204 an iterator over the fields of a struct or union type. Unlike
205 the standard Python "iteritems" method, it will recursively traverse
206 any anonymous fields.
210 ** "*stopped" events can report several new "reason"s, such as
213 ** Breakpoint changes are now notified using new async records, like
214 "=breakpoint-modified".
216 ** New command -ada-task-info.
218 * libthread-db-search-path now supports two special values: $sdir and $pdir.
219 $sdir specifies the default system locations of shared libraries.
220 $pdir specifies the directory where the libpthread used by the application
223 GDB no longer looks in $sdir and $pdir after it has searched the directories
224 mentioned in libthread-db-search-path. If you want to search those
225 directories, they must be specified in libthread-db-search-path.
226 The default value of libthread-db-search-path on GNU/Linux and Solaris
227 systems is now "$sdir:$pdir".
229 $pdir is not supported by gdbserver, it is currently ignored.
230 $sdir is supported by gdbserver.
232 * New configure option --with-iconv-bin.
233 When using the internationalization support like the one in the GNU C
234 library, GDB will invoke the "iconv" program to get a list of supported
235 character sets. If this program lives in a non-standard location, one can
236 use this option to specify where to find it.
238 * When natively debugging programs on PowerPC BookE processors running
239 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
240 watchpoints, which specify a mask in addition to an address to watch.
241 The mask specifies that some bits of an address (the bits which are
242 reset in the mask) should be ignored when matching the address accessed
243 by the inferior against the watchpoint address. See the "PowerPC Embedded"
244 section in the user manual for more details.
246 * The new option --once causes GDBserver to stop listening for connections once
247 the first connection is made. The listening port used by GDBserver will
248 become available after that.
250 * New commands "info macros" and "alias" have been added.
252 * New function parameters suffix @entry specifies value of function parameter
253 at the time the function got called. Entry values are available only since
259 "!" is now an alias of the "shell" command.
260 Note that no space is needed between "!" and SHELL COMMAND.
264 watch EXPRESSION mask MASK_VALUE
265 The watch command now supports the mask argument which allows creation
266 of masked watchpoints, if the current architecture supports this feature.
268 info auto-load-scripts [REGEXP]
269 This command was formerly named "maintenance print section-scripts".
270 It is now generally useful and is no longer a maintenance-only command.
272 info macro [-all] [--] MACRO
273 The info macro command has new options `-all' and `--'. The first for
274 printing all definitions of a macro. The second for explicitly specifying
275 the end of arguments and the beginning of the macro name in case the macro
276 name starts with a hyphen.
278 collect[/s] EXPRESSIONS
279 The tracepoint collect command now takes an optional modifier "/s"
280 that directs it to dereference pointer-to-character types and
281 collect the bytes of memory up to a zero byte. The behavior is
282 similar to what you see when you use the regular print command on a
283 string. An optional integer following the "/s" sets a bound on the
284 number of bytes that will be collected.
287 The trace start command now interprets any supplied arguments as a
288 note to be recorded with the trace run, with an effect similar to
289 setting the variable trace-notes.
292 The trace stop command now interprets any arguments as a note to be
293 mentioned along with the tstatus report that the trace was stopped
294 with a command. The effect is similar to setting the variable
297 * Tracepoints can now be enabled and disabled at any time after a trace
298 experiment has been started using the standard "enable" and "disable"
299 commands. It is now possible to start a trace experiment with no enabled
300 tracepoints; GDB will display a warning, but will allow the experiment to
301 begin, assuming that tracepoints will be enabled as needed while the trace
304 * Fast tracepoints on 32-bit x86-architectures can now be placed at
305 locations with 4-byte instructions, when they were previously
306 limited to locations with instructions of 5 bytes or longer.
312 Set the GDB prompt, and allow escape sequences to be inserted to
313 display miscellaneous information (see 'help set extended-prompt'
314 for the list of sequences). This prompt (and any information
315 accessed through the escape sequences) is updated every time the
318 set print entry-values (both|compact|default|if-needed|no|only|preferred)
319 show print entry-values
320 Set printing of frame argument values at function entry. In some cases
321 GDB can determine the value of function argument which was passed by the
322 function caller, even if the value was modified inside the called function.
324 set debug entry-values
325 show debug entry-values
326 Control display of debugging info for determining frame argument values at
327 function entry and virtual tail call frames.
329 set basenames-may-differ
330 show basenames-may-differ
331 Set whether a source file may have multiple base names.
332 (A "base name" is the name of a file with the directory part removed.
333 Example: The base name of "/home/user/hello.c" is "hello.c".)
334 If set, GDB will canonicalize file names (e.g., expand symlinks)
335 before comparing them. Canonicalization is an expensive operation,
336 but it allows the same file be known by more than one base name.
337 If not set (the default), all source files are assumed to have just
338 one base name, and gdb will do file name comparisons more efficiently.
344 Set a user name and notes for the current and any future trace runs.
345 This is useful for long-running and/or disconnected traces, to
346 inform others (or yourself) as to who is running the trace, supply
347 contact information, or otherwise explain what is going on.
350 show trace-stop-notes
351 Set a note attached to the trace run, that is displayed when the
352 trace has been stopped by a tstop command. This is useful for
353 instance as an explanation, if you are stopping a trace run that was
354 started by someone else.
360 Dynamically enable a tracepoint in a started trace experiment.
364 Dynamically disable a tracepoint in a started trace experiment.
368 Set the user and notes of the trace run.
372 Query the current status of a tracepoint.
376 Query the minimum length of instruction at which a fast tracepoint may
379 * Dcache size (number of lines) and line-size are now runtime-configurable
380 via "set dcache line" and "set dcache line-size" commands.
384 Texas Instruments TMS320C6x tic6x-*-*
388 Renesas RL78 rl78-*-elf
390 *** Changes in GDB 7.3.1
392 * The build failure for NetBSD and OpenBSD targets have now been fixed.
394 *** Changes in GDB 7.3
396 * GDB has a new command: "thread find [REGEXP]".
397 It finds the thread id whose name, target id, or thread extra info
398 matches the given regular expression.
400 * The "catch syscall" command now works on mips*-linux* targets.
402 * The -data-disassemble MI command now supports modes 2 and 3 for
403 dumping the instruction opcodes.
405 * New command line options
407 -data-directory DIR Specify DIR as the "data-directory".
408 This is mostly for testing purposes.
410 * The "maint set python auto-load on|off" command has been renamed to
411 "set auto-load-scripts on|off".
413 * GDB has a new command: "set directories".
414 It is like the "dir" command except that it replaces the
415 source path list instead of augmenting it.
417 * GDB now understands thread names.
419 On GNU/Linux, "info threads" will display the thread name as set by
420 prctl or pthread_setname_np.
422 There is also a new command, "thread name", which can be used to
423 assign a name internally for GDB to display.
426 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
427 has been integrated into GDB.
431 ** The function gdb.Write now accepts an optional keyword 'stream'.
432 This keyword, when provided, will direct the output to either
433 stdout, stderr, or GDB's logging output.
435 ** Parameters can now be be sub-classed in Python, and in particular
436 you may implement the get_set_doc and get_show_doc functions.
437 This improves how Parameter set/show documentation is processed
438 and allows for more dynamic content.
440 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
441 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
442 have an is_valid method.
444 ** Breakpoints can now be sub-classed in Python, and in particular
445 you may implement a 'stop' function that is executed each time
446 the inferior reaches that breakpoint.
448 ** New function gdb.lookup_global_symbol looks up a global symbol.
450 ** GDB values in Python are now callable if the value represents a
451 function. For example, if 'some_value' represents a function that
452 takes two integer parameters and returns a value, you can call
453 that function like so:
455 result = some_value (10,20)
457 ** Module gdb.types has been added.
458 It contains a collection of utilities for working with gdb.Types objects:
459 get_basic_type, has_field, make_enum_dict.
461 ** Module gdb.printing has been added.
462 It contains utilities for writing and registering pretty-printers.
463 New classes: PrettyPrinter, SubPrettyPrinter,
464 RegexpCollectionPrettyPrinter.
465 New function: register_pretty_printer.
467 ** New commands "info pretty-printers", "enable pretty-printer" and
468 "disable pretty-printer" have been added.
470 ** gdb.parameter("directories") is now available.
472 ** New function gdb.newest_frame returns the newest frame in the
475 ** The gdb.InferiorThread class has a new "name" attribute. This
476 holds the thread's name.
478 ** Python Support for Inferior events.
479 Python scripts can add observers to be notified of events
480 occurring in the process being debugged.
481 The following events are currently supported:
482 - gdb.events.cont Continue event.
483 - gdb.events.exited Inferior exited event.
484 - gdb.events.stop Signal received, and Breakpoint hit events.
488 ** GDB now puts template parameters in scope when debugging in an
489 instantiation. For example, if you have:
491 template<int X> int func (void) { return X; }
493 then if you step into func<5>, "print X" will show "5". This
494 feature requires proper debuginfo support from the compiler; it
495 was added to GCC 4.5.
497 ** The motion commands "next", "finish", "until", and "advance" now
498 work better when exceptions are thrown. In particular, GDB will
499 no longer lose control of the inferior; instead, the GDB will
500 stop the inferior at the point at which the exception is caught.
501 This functionality requires a change in the exception handling
502 code that was introduced in GCC 4.5.
504 * GDB now follows GCC's rules on accessing volatile objects when
505 reading or writing target state during expression evaluation.
506 One notable difference to prior behavior is that "print x = 0"
507 no longer generates a read of x; the value of the assignment is
508 now always taken directly from the value being assigned.
510 * GDB now has some support for using labels in the program's source in
511 linespecs. For instance, you can use "advance label" to continue
512 execution to a label.
514 * GDB now has support for reading and writing a new .gdb_index
515 section. This section holds a fast index of DWARF debugging
516 information and can be used to greatly speed up GDB startup and
517 operation. See the documentation for `save gdb-index' for details.
519 * The "watch" command now accepts an optional "-location" argument.
520 When used, this causes GDB to watch the memory referred to by the
521 expression. Such a watchpoint is never deleted due to it going out
524 * GDB now supports thread debugging of core dumps on GNU/Linux.
526 GDB now activates thread debugging using the libthread_db library
527 when debugging GNU/Linux core dumps, similarly to when debugging
528 live processes. As a result, when debugging a core dump file, GDB
529 is now able to display pthread_t ids of threads. For example, "info
530 threads" shows the same output as when debugging the process when it
531 was live. In earlier releases, you'd see something like this:
534 * 1 LWP 6780 main () at main.c:10
536 While now you see this:
539 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
541 It is also now possible to inspect TLS variables when debugging core
544 When debugging a core dump generated on a machine other than the one
545 used to run GDB, you may need to point GDB at the correct
546 libthread_db library with the "set libthread-db-search-path"
547 command. See the user manual for more details on this command.
549 * When natively debugging programs on PowerPC BookE processors running
550 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
551 which stop execution of the inferior whenever it executes an instruction
552 at any address within the specified range. See the "PowerPC Embedded"
553 section in the user manual for more details.
555 * New features in the GDB remote stub, GDBserver
557 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
558 and i686 LynxOS (version 5.x).
560 ** GDBserver is now supported on Blackfin Linux.
562 * New native configurations
564 ia64 HP-UX ia64-*-hpux*
568 Analog Devices, Inc. Blackfin Processor bfin-*
570 * Ada task switching is now supported on sparc-elf targets when
571 debugging a program using the Ravenscar Profile. For more information,
572 see the "Tasking Support when using the Ravenscar Profile" section
573 in the GDB user manual.
575 * Guile support was removed.
577 * New features in the GNU simulator
579 ** The --map-info flag lists all known core mappings.
581 ** CFI flashes may be simulated via the "cfi" device.
583 *** Changes in GDB 7.2
585 * Shared library support for remote targets by default
587 When GDB is configured for a generic, non-OS specific target, like
588 for example, --target=arm-eabi or one of the many *-*-elf targets,
589 GDB now queries remote stubs for loaded shared libraries using the
590 `qXfer:libraries:read' packet. Previously, shared library support
591 was always disabled for such configurations.
595 ** Argument Dependent Lookup (ADL)
597 In C++ ADL lookup directs function search to the namespaces of its
598 arguments even if the namespace has not been imported.
608 Here the compiler will search for `foo' in the namespace of 'b'
609 and find A::foo. GDB now supports this. This construct is commonly
610 used in the Standard Template Library for operators.
612 ** Improved User Defined Operator Support
614 In addition to member operators, GDB now supports lookup of operators
615 defined in a namespace and imported with a `using' directive, operators
616 defined in the global scope, operators imported implicitly from an
617 anonymous namespace, and the ADL operators mentioned in the previous
619 GDB now also supports proper overload resolution for all the previously
620 mentioned flavors of operators.
622 ** static const class members
624 Printing of static const class members that are initialized in the
625 class definition has been fixed.
627 * Windows Thread Information Block access.
629 On Windows targets, GDB now supports displaying the Windows Thread
630 Information Block (TIB) structure. This structure is visible either
631 by using the new command `info w32 thread-information-block' or, by
632 dereferencing the new convenience variable named `$_tlb', a
633 thread-specific pointer to the TIB. This feature is also supported
634 when remote debugging using GDBserver.
638 Static tracepoints are calls in the user program into a tracing
639 library. One such library is a port of the LTTng kernel tracer to
640 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
641 When debugging with GDBserver, GDB now supports combining the GDB
642 tracepoint machinery with such libraries. For example: the user can
643 use GDB to probe a static tracepoint marker (a call from the user
644 program into the tracing library) with the new "strace" command (see
645 "New commands" below). This creates a "static tracepoint" in the
646 breakpoint list, that can be manipulated with the same feature set
647 as fast and regular tracepoints. E.g., collect registers, local and
648 global variables, collect trace state variables, and define
649 tracepoint conditions. In addition, the user can collect extra
650 static tracepoint marker specific data, by collecting the new
651 $_sdata internal variable. When analyzing the trace buffer, you can
652 inspect $_sdata like any other variable available to GDB. For more
653 information, see the "Tracepoints" chapter in GDB user manual. New
654 remote packets have been defined to support static tracepoints, see
655 the "New remote packets" section below.
657 * Better reconstruction of tracepoints after disconnected tracing
659 GDB will attempt to download the original source form of tracepoint
660 definitions when starting a trace run, and then will upload these
661 upon reconnection to the target, resulting in a more accurate
662 reconstruction of the tracepoints that are in use on the target.
666 You can now exercise direct control over the ways that GDB can
667 affect your program. For instance, you can disallow the setting of
668 breakpoints, so that the program can run continuously (assuming
669 non-stop mode). In addition, the "observer" variable is available
670 to switch all of the different controls; in observer mode, GDB
671 cannot affect the target's behavior at all, which is useful for
672 tasks like diagnosing live systems in the field.
674 * The new convenience variable $_thread holds the number of the
681 Return the address of the Windows Thread Information Block of a given thread.
685 In response to several of the tracepoint packets, the target may now
686 also respond with a number of intermediate `qRelocInsn' request
687 packets before the final result packet, to have GDB handle
688 relocating an instruction to execute at a different address. This
689 is particularly useful for stubs that support fast tracepoints. GDB
690 reports support for this feature in the qSupported packet.
694 List static tracepoint markers in the target program.
698 List static tracepoint markers at a given address in the target
701 qXfer:statictrace:read
703 Read the static trace data collected (by a `collect $_sdata'
704 tracepoint action). The remote stub reports support for this packet
705 to gdb's qSupported query.
709 Send the current settings of GDB's permission flags.
713 Send part of the source (textual) form of a tracepoint definition,
714 which includes location, conditional, and action list.
716 * The source command now accepts a -s option to force searching for the
717 script in the source search path even if the script name specifies
720 * New features in the GDB remote stub, GDBserver
722 - GDBserver now support tracepoints (including fast tracepoints, and
723 static tracepoints). The feature is currently supported by the
724 i386-linux and amd64-linux builds. See the "Tracepoints support
725 in gdbserver" section in the manual for more information.
727 GDBserver JIT compiles the tracepoint's conditional agent
728 expression bytecode into native code whenever possible for low
729 overhead dynamic tracepoints conditionals. For such tracepoints,
730 an expression that examines program state is evaluated when the
731 tracepoint is reached, in order to determine whether to capture
732 trace data. If the condition is simple and false, processing the
733 tracepoint finishes very quickly and no data is gathered.
735 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
736 for static tracepoints support.
738 - GDBserver now supports x86_64 Windows 64-bit debugging.
740 * GDB now sends xmlRegisters= in qSupported packet to indicate that
741 it understands register description.
743 * The --batch flag now disables pagination and queries.
745 * X86 general purpose registers
747 GDB now supports reading/writing byte, word and double-word x86
748 general purpose registers directly. This means you can use, say,
749 $ah or $ax to refer, respectively, to the byte register AH and
750 16-bit word register AX that are actually portions of the 32-bit
751 register EAX or 64-bit register RAX.
753 * The `commands' command now accepts a range of breakpoints to modify.
754 A plain `commands' following a command that creates multiple
755 breakpoints affects all the breakpoints set by that command. This
756 applies to breakpoints set by `rbreak', and also applies when a
757 single `break' command creates multiple breakpoints (e.g.,
758 breakpoints on overloaded c++ functions).
760 * The `rbreak' command now accepts a filename specification as part of
761 its argument, limiting the functions selected by the regex to those
762 in the specified file.
764 * Support for remote debugging Windows and SymbianOS shared libraries
765 from Unix hosts has been improved. Non Windows GDB builds now can
766 understand target reported file names that follow MS-DOS based file
767 system semantics, such as file names that include drive letters and
768 use the backslash character as directory separator. This makes it
769 possible to transparently use the "set sysroot" and "set
770 solib-search-path" on Unix hosts to point as host copies of the
771 target's shared libraries. See the new command "set
772 target-file-system-kind" described below, and the "Commands to
773 specify files" section in the user manual for more information.
777 eval template, expressions...
778 Convert the values of one or more expressions under the control
779 of the string template to a command line, and call it.
781 set target-file-system-kind unix|dos-based|auto
782 show target-file-system-kind
783 Set or show the assumed file system kind for target reported file
786 save breakpoints <filename>
787 Save all current breakpoint definitions to a file suitable for use
788 in a later debugging session. To read the saved breakpoint
789 definitions, use the `source' command.
791 `save tracepoints' is a new alias for `save-tracepoints'. The latter
794 info static-tracepoint-markers
795 Display information about static tracepoint markers in the target.
797 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
798 Define a static tracepoint by probing a marker at the given
799 function, line, address, or marker ID.
803 Enable and disable observer mode.
805 set may-write-registers on|off
806 set may-write-memory on|off
807 set may-insert-breakpoints on|off
808 set may-insert-tracepoints on|off
809 set may-insert-fast-tracepoints on|off
810 set may-interrupt on|off
811 Set individual permissions for GDB effects on the target. Note that
812 some of these settings can have undesirable or surprising
813 consequences, particularly when changed in the middle of a session.
814 For instance, disabling the writing of memory can prevent
815 breakpoints from being inserted, cause single-stepping to fail, or
816 even crash your program, if you disable after breakpoints have been
817 inserted. However, GDB should not crash.
819 set record memory-query on|off
820 show record memory-query
821 Control whether to stop the inferior if memory changes caused
822 by an instruction cannot be recorded.
827 The disassemble command now supports "start,+length" form of two arguments.
831 ** GDB now provides a new directory location, called the python directory,
832 where Python scripts written for GDB can be installed. The location
833 of that directory is <data-directory>/python, where <data-directory>
834 is the GDB data directory. For more details, see section `Scripting
835 GDB using Python' in the manual.
837 ** The GDB Python API now has access to breakpoints, symbols, symbol
838 tables, program spaces, inferiors, threads and frame's code blocks.
839 Additionally, GDB Parameters can now be created from the API, and
840 manipulated via set/show in the CLI.
842 ** New functions gdb.target_charset, gdb.target_wide_charset,
843 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
845 ** New exception gdb.GdbError.
847 ** Pretty-printers are now also looked up in the current program space.
849 ** Pretty-printers can now be individually enabled and disabled.
851 ** GDB now looks for names of Python scripts to auto-load in a
852 special section named `.debug_gdb_scripts', in addition to looking
853 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
855 * Tracepoint actions were unified with breakpoint commands. In particular,
856 there are no longer differences in "info break" output for breakpoints and
857 tracepoints and the "commands" command can be used for both tracepoints and
862 ARM Symbian arm*-*-symbianelf*
864 * D language support.
865 GDB now supports debugging programs written in the D programming
868 * GDB now supports the extended ptrace interface for PowerPC which is
869 available since Linux kernel version 2.6.34. This automatically enables
870 any hardware breakpoints and additional hardware watchpoints available in
871 the processor. The old ptrace interface exposes just one hardware
872 watchpoint and no hardware breakpoints.
874 * GDB is now able to use the Data Value Compare (DVC) register available on
875 embedded PowerPC processors to implement in hardware simple watchpoint
876 conditions of the form:
878 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
880 This works in native GDB running on Linux kernels with the extended ptrace
881 interface mentioned above.
883 *** Changes in GDB 7.1
889 GDB now supports importing of namespaces in C++. This enables the
890 user to inspect variables from imported namespaces. Support for
891 namepace aliasing has also been added. So, if a namespace is
892 aliased in the current scope (e.g. namepace C=A; ) the user can
893 print variables using the alias (e.g. (gdb) print C::x).
897 All known bugs relating to the printing of virtual base class were
898 fixed. It is now possible to call overloaded static methods using a
903 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
904 and reinterpret_cast<> are now handled by the C++ expression parser.
908 Xilinx MicroBlaze microblaze-*-*
913 Xilinx MicroBlaze microblaze
916 * Multi-program debugging.
918 GDB now has support for multi-program (a.k.a. multi-executable or
919 multi-exec) debugging. This allows for debugging multiple inferiors
920 simultaneously each running a different program under the same GDB
921 session. See "Debugging Multiple Inferiors and Programs" in the
922 manual for more information. This implied some user visible changes
923 in the multi-inferior support. For example, "info inferiors" now
924 lists inferiors that are not running yet or that have exited
925 already. See also "New commands" and "New options" below.
927 * New tracing features
929 GDB's tracepoint facility now includes several new features:
931 ** Trace state variables
933 GDB tracepoints now include support for trace state variables, which
934 are variables managed by the target agent during a tracing
935 experiment. They are useful for tracepoints that trigger each
936 other, so for instance one tracepoint can count hits in a variable,
937 and then a second tracepoint has a condition that is true when the
938 count reaches a particular value. Trace state variables share the
939 $-syntax of GDB convenience variables, and can appear in both
940 tracepoint actions and condition expressions. Use the "tvariable"
941 command to create, and "info tvariables" to view; see "Trace State
942 Variables" in the manual for more detail.
946 GDB now includes an option for defining fast tracepoints, which
947 targets may implement more efficiently, such as by installing a jump
948 into the target agent rather than a trap instruction. The resulting
949 speedup can be by two orders of magnitude or more, although the
950 tradeoff is that some program locations on some target architectures
951 might not allow fast tracepoint installation, for instance if the
952 instruction to be replaced is shorter than the jump. To request a
953 fast tracepoint, use the "ftrace" command, with syntax identical to
954 the regular trace command.
956 ** Disconnected tracing
958 It is now possible to detach GDB from the target while it is running
959 a trace experiment, then reconnect later to see how the experiment
960 is going. In addition, a new variable disconnected-tracing lets you
961 tell the target agent whether to continue running a trace if the
962 connection is lost unexpectedly.
966 GDB now has the ability to save the trace buffer into a file, and
967 then use that file as a target, similarly to you can do with
968 corefiles. You can select trace frames, print data that was
969 collected in them, and use tstatus to display the state of the
970 tracing run at the moment that it was saved. To create a trace
971 file, use "tsave <filename>", and to use it, do "target tfile
974 ** Circular trace buffer
976 You can ask the target agent to handle the trace buffer as a
977 circular buffer, discarding the oldest trace frames to make room for
978 newer ones, by setting circular-trace-buffer to on. This feature may
979 not be available for all target agents.
984 The disassemble command, when invoked with two arguments, now requires
985 the arguments to be comma-separated.
988 The info variables command now displays variable definitions. Files
989 which only declare a variable are not shown.
992 The source command is now capable of sourcing Python scripts.
993 This feature is dependent on the debugger being build with Python
996 Related to this enhancement is also the introduction of a new command
997 "set script-extension" (see below).
999 * New commands (for set/show, see "New options" below)
1001 record save [<FILENAME>]
1002 Save a file (in core file format) containing the process record
1003 execution log for replay debugging at a later time.
1005 record restore <FILENAME>
1006 Restore the process record execution log that was saved at an
1007 earlier time, for replay debugging.
1009 add-inferior [-copies <N>] [-exec <FILENAME>]
1012 clone-inferior [-copies <N>] [ID]
1013 Make a new inferior ready to execute the same program another
1014 inferior has loaded.
1019 maint info program-spaces
1020 List the program spaces loaded into GDB.
1022 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1023 show remote interrupt-sequence
1024 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1025 as the sequence to the remote target in order to interrupt the execution.
1026 Ctrl-C is a default. Some system prefers BREAK which is high level of
1027 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1028 Magic SysRq g. It is BREAK signal and character 'g'.
1030 set remote interrupt-on-connect [on | off]
1031 show remote interrupt-on-connect
1032 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1033 remote target when gdb connects to it. This is needed when you debug
1036 set remotebreak [on | off]
1038 Deprecated. Use "set/show remote interrupt-sequence" instead.
1040 tvariable $NAME [ = EXP ]
1041 Create or modify a trace state variable.
1044 List trace state variables and their values.
1046 delete tvariable $NAME ...
1047 Delete one or more trace state variables.
1050 Evaluate the given expressions without collecting anything into the
1051 trace buffer. (Valid in tracepoint actions only.)
1053 ftrace FN / FILE:LINE / *ADDR
1054 Define a fast tracepoint at the given function, line, or address.
1056 * New expression syntax
1058 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1059 GDB now parses 0b101010 identically with 42.
1063 set follow-exec-mode new|same
1064 show follow-exec-mode
1065 Control whether GDB reuses the same inferior across an exec call or
1066 creates a new one. This is useful to be able to restart the old
1067 executable after the inferior having done an exec call.
1069 set default-collect EXPR, ...
1070 show default-collect
1071 Define a list of expressions to be collected at each tracepoint.
1072 This is a useful way to ensure essential items are not overlooked,
1073 such as registers or a critical global variable.
1075 set disconnected-tracing
1076 show disconnected-tracing
1077 If set to 1, the target is instructed to continue tracing if it
1078 loses its connection to GDB. If 0, the target is to stop tracing
1081 set circular-trace-buffer
1082 show circular-trace-buffer
1083 If set to on, the target is instructed to use a circular trace buffer
1084 and discard the oldest trace frames instead of stopping the trace due
1085 to a full trace buffer. If set to off, the trace stops when the buffer
1086 fills up. Some targets may not support this.
1088 set script-extension off|soft|strict
1089 show script-extension
1090 If set to "off", the debugger does not perform any script language
1091 recognition, and all sourced files are assumed to be GDB scripts.
1092 If set to "soft" (the default), files are sourced according to
1093 filename extension, falling back to GDB scripts if the first
1095 If set to "strict", files are sourced according to filename extension.
1097 set ada trust-PAD-over-XVS on|off
1098 show ada trust-PAD-over-XVS
1099 If off, activate a workaround against a bug in the debugging information
1100 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1101 the GCC sources for more information about the GNAT encoding and
1102 PAD types in particular). It is always safe to set this option to
1103 off, but this introduces a slight performance penalty. The default
1106 * Python API Improvements
1108 ** GDB provides the new class gdb.LazyString. This is useful in
1109 some pretty-printing cases. The new method gdb.Value.lazy_string
1110 provides a simple way to create objects of this type.
1112 ** The fields returned by gdb.Type.fields now have an
1113 `is_base_class' attribute.
1115 ** The new method gdb.Type.range returns the range of an array type.
1117 ** The new method gdb.parse_and_eval can be used to parse and
1118 evaluate an expression.
1120 * New remote packets
1123 Define a trace state variable.
1126 Get the current value of a trace state variable.
1129 Set desired tracing behavior upon disconnection.
1132 Set the trace buffer to be linear or circular.
1135 Get data about the tracepoints currently in use.
1139 Process record now works correctly with hardware watchpoints.
1141 Multiple bug fixes have been made to the mips-irix port, making it
1142 much more reliable. In particular:
1143 - Debugging threaded applications is now possible again. Previously,
1144 GDB would hang while starting the program, or while waiting for
1145 the program to stop at a breakpoint.
1146 - Attaching to a running process no longer hangs.
1147 - An error occurring while loading a core file has been fixed.
1148 - Changing the value of the PC register now works again. This fixes
1149 problems observed when using the "jump" command, or when calling
1150 a function from GDB, or even when assigning a new value to $pc.
1151 - With the "finish" and "return" commands, the return value for functions
1152 returning a small array is now correctly printed.
1153 - It is now possible to break on shared library code which gets executed
1154 during a shared library init phase (code executed while executing
1155 their .init section). Previously, the breakpoint would have no effect.
1156 - GDB is now able to backtrace through the signal handler for
1157 non-threaded programs.
1159 PIE (Position Independent Executable) programs debugging is now supported.
1160 This includes debugging execution of PIC (Position Independent Code) shared
1161 libraries although for that, it should be possible to run such libraries as an
1164 *** Changes in GDB 7.0
1166 * GDB now has an interface for JIT compilation. Applications that
1167 dynamically generate code can create symbol files in memory and register
1168 them with GDB. For users, the feature should work transparently, and
1169 for JIT developers, the interface is documented in the GDB manual in the
1170 "JIT Compilation Interface" chapter.
1172 * Tracepoints may now be conditional. The syntax is as for
1173 breakpoints; either an "if" clause appended to the "trace" command,
1174 or the "condition" command is available. GDB sends the condition to
1175 the target for evaluation using the same bytecode format as is used
1176 for tracepoint actions.
1178 * The disassemble command now supports: an optional /r modifier, print the
1179 raw instructions in hex as well as in symbolic form, and an optional /m
1180 modifier to print mixed source+assembly.
1182 * Process record and replay
1184 In a architecture environment that supports ``process record and
1185 replay'', ``process record and replay'' target can record a log of
1186 the process execution, and replay it with both forward and reverse
1189 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1190 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1191 set execution-direction {forward|reverse}, for targets that support
1194 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1195 feature is available with a native GDB running on kernel version
1198 * GDB now has support for multi-byte and wide character sets on the
1199 target. Strings whose character type is wchar_t, char16_t, or
1200 char32_t are now correctly printed. GDB supports wide- and unicode-
1201 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1202 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1203 `printf'. This feature requires iconv to work properly; if your
1204 system does not have a working iconv, GDB can use GNU libiconv. See
1205 the installation instructions for more information.
1207 * GDB now supports automatic retrieval of shared library files from
1208 remote targets. To use this feature, specify a system root that begins
1209 with the `remote:' prefix, either via the `set sysroot' command or via
1210 the `--with-sysroot' configure-time option.
1212 * "info sharedlibrary" now takes an optional regex of libraries to show,
1213 and it now reports if a shared library has no debugging information.
1215 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1216 now complete on file names.
1218 * When completing in expressions, gdb will attempt to limit
1219 completions to allowable structure or union fields, where appropriate.
1220 For instance, consider:
1222 # struct example { int f1; double f2; };
1223 # struct example variable;
1226 If the user types TAB at the end of this command line, the available
1227 completions will be "f1" and "f2".
1229 * Inlined functions are now supported. They show up in backtraces, and
1230 the "step", "next", and "finish" commands handle them automatically.
1232 * GDB now supports the token-splicing (##) and stringification (#)
1233 operators when expanding macros. It also supports variable-arity
1236 * GDB now supports inspecting extra signal information, exported by
1237 the new $_siginfo convenience variable. The feature is currently
1238 implemented on linux ARM, i386 and amd64.
1240 * GDB can now display the VFP floating point registers and NEON vector
1241 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1242 can provide these registers (requires Linux 2.6.30 or later). Remote
1243 and simulator targets may also provide them.
1245 * New remote packets
1248 Search memory for a sequence of bytes.
1251 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1252 operation over reliable transport links. Use of this packet is
1253 controlled by the `set remote noack-packet' command.
1256 Kill the process with the specified process ID. Use this in preference
1257 to `k' when multiprocess protocol extensions are supported.
1260 Obtains additional operating system information
1264 Read or write additional signal information.
1266 * Removed remote protocol undocumented extension
1268 An undocumented extension to the remote protocol's `S' stop reply
1269 packet that permited the stub to pass a process id was removed.
1270 Remote servers should use the `T' stop reply packet instead.
1272 * GDB now supports multiple function calling conventions according to the
1273 DWARF-2 DW_AT_calling_convention function attribute.
1275 * The SH target utilizes the aforementioned change to distinguish between gcc
1276 and Renesas calling convention. It also adds the new CLI commands
1277 `set/show sh calling-convention'.
1279 * GDB can now read compressed debug sections, as produced by GNU gold
1280 with the --compress-debug-sections=zlib flag.
1282 * 64-bit core files are now supported on AIX.
1284 * Thread switching is now supported on Tru64.
1286 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1287 which will be allocated using malloc later in program execution.
1289 * The qXfer:libraries:read remote procotol packet now allows passing a
1290 list of section offsets.
1292 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1293 conditions handling signals delivered during attach or thread creation
1294 have also been fixed.
1296 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1297 From the user's standpoint, all unqualified instances of True and False
1298 are treated as the standard definitions, regardless of context.
1300 * GDB now parses C++ symbol and type names more flexibly. For
1303 template<typename T> class C { };
1306 GDB will now correctly handle all of:
1308 ptype C<char const *>
1309 ptype C<char const*>
1310 ptype C<const char *>
1311 ptype C<const char*>
1313 * New features in the GDB remote stub, gdbserver
1315 - The "--wrapper" command-line argument tells gdbserver to use a
1316 wrapper program to launch programs for debugging.
1318 - On PowerPC and S/390 targets, it is now possible to use a single
1319 gdbserver executable to debug both 32-bit and 64-bit programs.
1320 (This requires gdbserver itself to be built as a 64-bit executable.)
1322 - gdbserver uses the new noack protocol mode for TCP connections to
1323 reduce communications latency, if also supported and enabled in GDB.
1325 - Support for the sparc64-linux-gnu target is now included in
1328 - The amd64-linux build of gdbserver now supports debugging both
1329 32-bit and 64-bit programs.
1331 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1332 now support hardware watchpoints, and will use them automatically
1337 GDB now has support for scripting using Python. Whether this is
1338 available is determined at configure time.
1340 New GDB commands can now be written in Python.
1342 * Ada tasking support
1344 Ada tasks can now be inspected in GDB. The following commands have
1348 Print the list of Ada tasks.
1350 Print detailed information about task number N.
1352 Print the task number of the current task.
1354 Switch the context of debugging to task number N.
1356 * Support for user-defined prefixed commands. The "define" command can
1357 add new commands to existing prefixes, e.g. "target".
1359 * Multi-inferior, multi-process debugging.
1361 GDB now has generalized support for multi-inferior debugging. See
1362 "Debugging Multiple Inferiors" in the manual for more information.
1363 Although availability still depends on target support, the command
1364 set is more uniform now. The GNU/Linux specific multi-forks support
1365 has been migrated to this new framework. This implied some user
1366 visible changes; see "New commands" and also "Removed commands"
1369 * Target descriptions can now describe the target OS ABI. See the
1370 "Target Description Format" section in the user manual for more
1373 * Target descriptions can now describe "compatible" architectures
1374 to indicate that the target can execute applications for a different
1375 architecture in addition to those for the main target architecture.
1376 See the "Target Description Format" section in the user manual for
1379 * Multi-architecture debugging.
1381 GDB now includes general supports for debugging applications on
1382 hybrid systems that use more than one single processor architecture
1383 at the same time. Each such hybrid architecture still requires
1384 specific support to be added. The only hybrid architecture supported
1385 in this version of GDB is the Cell Broadband Engine.
1387 * GDB now supports integrated debugging of Cell/B.E. applications that
1388 use both the PPU and SPU architectures. To enable support for hybrid
1389 Cell/B.E. debugging, you need to configure GDB to support both the
1390 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1391 --enable-targets configure option.
1393 * Non-stop mode debugging.
1395 For some targets, GDB now supports an optional mode of operation in
1396 which you can examine stopped threads while other threads continue
1397 to execute freely. This is referred to as non-stop mode, with the
1398 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1399 section in the user manual for more information.
1401 To be able to support remote non-stop debugging, a remote stub needs
1402 to implement the non-stop mode remote protocol extensions, as
1403 described in the "Remote Non-Stop" section of the user manual. The
1404 GDB remote stub, gdbserver, has been adjusted to support these
1405 extensions on linux targets.
1407 * New commands (for set/show, see "New options" below)
1409 catch syscall [NAME(S) | NUMBER(S)]
1410 Catch system calls. Arguments, which should be names of system
1411 calls or their numbers, mean catch only those syscalls. Without
1412 arguments, every syscall will be caught. When the inferior issues
1413 any of the specified syscalls, GDB will stop and announce the system
1414 call, both when it is called and when its call returns. This
1415 feature is currently available with a native GDB running on the
1416 Linux Kernel, under the following architectures: x86, x86_64,
1417 PowerPC and PowerPC64.
1419 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1421 Search memory for a sequence of bytes.
1423 maint set python print-stack
1424 maint show python print-stack
1425 Show a stack trace when an error is encountered in a Python script.
1428 Invoke CODE by passing it to the Python interpreter.
1433 These allow macros to be defined, undefined, and listed
1437 Show operating system information about processes.
1440 List the inferiors currently under GDB's control.
1443 Switch focus to inferior number NUM.
1446 Detach from inferior number NUM.
1449 Kill inferior number NUM.
1453 set spu stop-on-load
1454 show spu stop-on-load
1455 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1457 set spu auto-flush-cache
1458 show spu auto-flush-cache
1459 Control whether to automatically flush the software-managed cache
1460 during Cell/B.E. debugging.
1462 set sh calling-convention
1463 show sh calling-convention
1464 Control the calling convention used when calling SH target functions.
1467 show debug timestamp
1468 Control display of timestamps with GDB debugging output.
1470 set disassemble-next-line
1471 show disassemble-next-line
1472 Control display of disassembled source lines or instructions when
1475 set remote noack-packet
1476 show remote noack-packet
1477 Set/show the use of remote protocol QStartNoAckMode packet. See above
1478 under "New remote packets."
1480 set remote query-attached-packet
1481 show remote query-attached-packet
1482 Control use of remote protocol `qAttached' (query-attached) packet.
1484 set remote read-siginfo-object
1485 show remote read-siginfo-object
1486 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1489 set remote write-siginfo-object
1490 show remote write-siginfo-object
1491 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1494 set remote reverse-continue
1495 show remote reverse-continue
1496 Control use of remote protocol 'bc' (reverse-continue) packet.
1498 set remote reverse-step
1499 show remote reverse-step
1500 Control use of remote protocol 'bs' (reverse-step) packet.
1502 set displaced-stepping
1503 show displaced-stepping
1504 Control displaced stepping mode. Displaced stepping is a way to
1505 single-step over breakpoints without removing them from the debuggee.
1506 Also known as "out-of-line single-stepping".
1509 show debug displaced
1510 Control display of debugging info for displaced stepping.
1512 maint set internal-error
1513 maint show internal-error
1514 Control what GDB does when an internal error is detected.
1516 maint set internal-warning
1517 maint show internal-warning
1518 Control what GDB does when an internal warning is detected.
1523 Use a wrapper program to launch programs for debugging.
1525 set multiple-symbols (all|ask|cancel)
1526 show multiple-symbols
1527 The value of this variable can be changed to adjust the debugger behavior
1528 when an expression or a breakpoint location contains an ambiguous symbol
1529 name (an overloaded function name, for instance).
1531 set breakpoint always-inserted
1532 show breakpoint always-inserted
1533 Keep breakpoints always inserted in the target, as opposed to inserting
1534 them when resuming the target, and removing them when the target stops.
1535 This option can improve debugger performance on slow remote targets.
1537 set arm fallback-mode (arm|thumb|auto)
1538 show arm fallback-mode
1539 set arm force-mode (arm|thumb|auto)
1541 These commands control how ARM GDB determines whether instructions
1542 are ARM or Thumb. The default for both settings is auto, which uses
1543 the current CPSR value for instructions without symbols; previous
1544 versions of GDB behaved as if "set arm fallback-mode arm".
1546 set disable-randomization
1547 show disable-randomization
1548 Standalone programs run with the virtual address space randomization enabled
1549 by default on some platforms. This option keeps the addresses stable across
1550 multiple debugging sessions.
1554 Control whether other threads are stopped or not when some thread hits
1559 Requests that asynchronous execution is enabled in the target, if available.
1560 In this case, it's possible to resume target in the background, and interact
1561 with GDB while the target is running. "show target-async" displays the
1562 current state of asynchronous execution of the target.
1564 set target-wide-charset
1565 show target-wide-charset
1566 The target-wide-charset is the name of the character set that GDB
1567 uses when printing characters whose type is wchar_t.
1569 set tcp auto-retry (on|off)
1571 set tcp connect-timeout
1572 show tcp connect-timeout
1573 These commands allow GDB to retry failed TCP connections to a remote stub
1574 with a specified timeout period; this is useful if the stub is launched
1575 in parallel with GDB but may not be ready to accept connections immediately.
1577 set libthread-db-search-path
1578 show libthread-db-search-path
1579 Control list of directories which GDB will search for appropriate
1582 set schedule-multiple (on|off)
1583 show schedule-multiple
1584 Allow GDB to resume all threads of all processes or only threads of
1585 the current process.
1589 Use more aggressive caching for accesses to the stack. This improves
1590 performance of remote debugging (particularly backtraces) without
1591 affecting correctness.
1593 set interactive-mode (on|off|auto)
1594 show interactive-mode
1595 Control whether GDB runs in interactive mode (on) or not (off).
1596 When in interactive mode, GDB waits for the user to answer all
1597 queries. Otherwise, GDB does not wait and assumes the default
1598 answer. When set to auto (the default), GDB determines which
1599 mode to use based on the stdin settings.
1604 For program forks, this is replaced by the new more generic `info
1605 inferiors' command. To list checkpoints, you can still use the
1606 `info checkpoints' command, which was an alias for the `info forks'
1610 Replaced by the new `inferior' command. To switch between
1611 checkpoints, you can still use the `restart' command, which was an
1612 alias for the `fork' command.
1615 This is removed, since some targets don't have a notion of
1616 processes. To switch between processes, you can still use the
1617 `inferior' command using GDB's own inferior number.
1620 For program forks, this is replaced by the new more generic `kill
1621 inferior' command. To delete a checkpoint, you can still use the
1622 `delete checkpoint' command, which was an alias for the `delete
1626 For program forks, this is replaced by the new more generic `detach
1627 inferior' command. To detach a checkpoint, you can still use the
1628 `detach checkpoint' command, which was an alias for the `detach
1631 * New native configurations
1633 x86/x86_64 Darwin i[34567]86-*-darwin*
1635 x86_64 MinGW x86_64-*-mingw*
1639 Lattice Mico32 lm32-*
1640 x86 DICOS i[34567]86-*-dicos*
1641 x86_64 DICOS x86_64-*-dicos*
1644 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1645 (mingw32ce) debugging.
1651 These commands were actually not implemented on any target.
1653 *** Changes in GDB 6.8
1655 * New native configurations
1657 NetBSD/hppa hppa*-*netbsd*
1658 Xtensa GNU/Linux xtensa*-*-linux*
1662 NetBSD/hppa hppa*-*-netbsd*
1663 Xtensa GNU/Lunux xtensa*-*-linux*
1665 * Change in command line behavior -- corefiles vs. process ids.
1667 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1668 attaching to process NUMBER fails, GDB no longer attempts to open a
1669 core file named NUMBER. Attaching to a program using the -c option
1670 is no longer supported. Instead, use the '-p' or '--pid' options.
1672 * GDB can now be built as a native debugger for debugging Windows x86
1673 (mingw32) Portable Executable (PE) programs.
1675 * Pending breakpoints no longer change their number when their address
1678 * GDB now supports breakpoints with multiple locations,
1679 including breakpoints on C++ constructors, inside C++ templates,
1680 and in inlined functions.
1682 * GDB's ability to debug optimized code has been improved. GDB more
1683 accurately identifies function bodies and lexical blocks that occupy
1684 more than one contiguous range of addresses.
1686 * Target descriptions can now describe registers for PowerPC.
1688 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1689 registers on PowerPC targets.
1691 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1692 targets even when the libthread_db library is not available.
1694 * The GDB remote stub, gdbserver, now supports the new file transfer
1695 commands (remote put, remote get, and remote delete).
1697 * The GDB remote stub, gdbserver, now supports run and attach in
1698 extended-remote mode.
1700 * hppa*64*-*-hpux11* target broken
1701 The debugger is unable to start a program and fails with the following
1702 error: "Error trying to get information about dynamic linker".
1703 The gdb-6.7 release is also affected.
1705 * GDB now supports the --enable-targets= configure option to allow
1706 building a single GDB executable that supports multiple remote
1707 target architectures.
1709 * GDB now supports debugging C and C++ programs which use the
1710 Decimal Floating Point extension. In addition, the PowerPC target
1711 now has a set of pseudo-registers to inspect decimal float values
1712 stored in two consecutive float registers.
1714 * The -break-insert MI command can optionally create pending
1717 * Improved support for debugging Ada
1718 Many improvements to the Ada language support have been made. These
1720 - Better support for Ada2005 interface types
1721 - Improved handling of arrays and slices in general
1722 - Better support for Taft-amendment types
1723 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1725 - Improved command completion in Ada
1728 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1733 set print frame-arguments (all|scalars|none)
1734 show print frame-arguments
1735 The value of this variable can be changed to control which argument
1736 values should be printed by the debugger when displaying a frame.
1741 Transfer files to and from a remote target, and delete remote files.
1748 Transfer files to and from a remote target, and delete remote files.
1750 * New remote packets
1757 Open, close, read, write, and delete files on the remote system.
1760 Attach to an existing process on the remote system, in extended-remote
1764 Run a new process on the remote system, in extended-remote mode.
1766 *** Changes in GDB 6.7
1768 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1769 bfd, libiberty and opcodes, as revealed by static analysis donated by
1770 Coverity, Inc. (http://scan.coverity.com).
1772 * When looking up multiply-defined global symbols, GDB will now prefer the
1773 symbol definition in the current shared library if it was built using the
1774 -Bsymbolic linker option.
1776 * When the Text User Interface (TUI) is not configured, GDB will now
1777 recognize the -tui command-line option and print a message that the TUI
1780 * The GDB remote stub, gdbserver, now has lower overhead for high
1781 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1783 * GDB for MIPS targets now autodetects whether a remote target provides
1784 32-bit or 64-bit register values.
1786 * Support for C++ member pointers has been improved.
1788 * GDB now understands XML target descriptions, which specify the
1789 target's overall architecture. GDB can read a description from
1790 a local file or over the remote serial protocol.
1792 * Vectors of single-byte data use a new integer type which is not
1793 automatically displayed as character or string data.
1795 * The /s format now works with the print command. It displays
1796 arrays of single-byte integers and pointers to single-byte integers
1799 * Target descriptions can now describe target-specific registers,
1800 for architectures which have implemented the support (currently
1801 only ARM, M68K, and MIPS).
1803 * GDB and the GDB remote stub, gdbserver, now support the XScale
1806 * The GDB remote stub, gdbserver, has been updated to support
1807 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1808 has been rewritten to use the standard GDB remote protocol.
1810 * GDB can now step into C++ functions which are called through thunks.
1812 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1814 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1815 layout. It also supports a TextSeg= and DataSeg= response when only
1816 segment base addresses (rather than offsets) are available.
1818 * The /i format now outputs any trailing branch delay slot instructions
1819 immediately following the last instruction within the count specified.
1821 * The GDB remote protocol "T" stop reply packet now supports a
1822 "library" response. Combined with the new "qXfer:libraries:read"
1823 packet, this response allows GDB to debug shared libraries on targets
1824 where the operating system manages the list of loaded libraries (e.g.
1825 Windows and SymbianOS).
1827 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1828 (DLLs) on Windows and Windows CE targets.
1830 * GDB now supports a faster verification that a .debug file matches its binary
1831 according to its build-id signature, if the signature is present.
1837 Enable or disable hardware flow control (RTS/CTS) on the serial port
1838 when debugging using remote targets.
1840 set mem inaccessible-by-default
1841 show mem inaccessible-by-default
1842 If the target supplies a memory map, for instance via the remote
1843 protocol's "qXfer:memory-map:read" packet, setting this variable
1844 prevents GDB from accessing memory outside the memory map. This
1845 is useful for targets with memory mapped registers or which react
1846 badly to accesses of unmapped address space.
1848 set breakpoint auto-hw
1849 show breakpoint auto-hw
1850 If the target supplies a memory map, for instance via the remote
1851 protocol's "qXfer:memory-map:read" packet, setting this variable
1852 lets GDB use hardware breakpoints automatically for memory regions
1853 where it can not use software breakpoints. This covers both the
1854 "break" command and internal breakpoints used for other commands
1855 including "next" and "finish".
1858 catch exception unhandled
1859 Stop the program execution when Ada exceptions are raised.
1862 Stop the program execution when an Ada assertion failed.
1866 Set an alternate system root for target files. This is a more
1867 general version of "set solib-absolute-prefix", which is now
1868 an alias to "set sysroot".
1871 Provide extended SPU facility status information. This set of
1872 commands is available only when debugging the Cell/B.E. SPU
1875 * New native configurations
1877 OpenBSD/sh sh*-*openbsd*
1880 unset tdesc filename
1882 Use the specified local file as an XML target description, and do
1883 not query the target for its built-in description.
1887 OpenBSD/sh sh*-*-openbsd*
1888 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1889 Toshiba Media Processor mep-elf
1891 * New remote packets
1894 Ignore the specified signals; pass them directly to the debugged program
1895 without stopping other threads or reporting them to GDB.
1897 qXfer:features:read:
1898 Read an XML target description from the target, which describes its
1903 Read or write contents of an spufs file on the target system. These
1904 packets are available only on the Cell/B.E. SPU architecture.
1906 qXfer:libraries:read:
1907 Report the loaded shared libraries. Combined with new "T" packet
1908 response, this packet allows GDB to debug shared libraries on
1909 targets where the operating system manages the list of loaded
1910 libraries (e.g. Windows and SymbianOS).
1914 Support for these obsolete configurations has been removed.
1922 i[34567]86-*-lynxos*
1923 i[34567]86-*-netware*
1924 i[34567]86-*-sco3.2v5*
1925 i[34567]86-*-sco3.2v4*
1927 i[34567]86-*-sysv4.2*
1930 i[34567]86-*-unixware2*
1931 i[34567]86-*-unixware*
1940 * Other removed features
1947 Various m68k-only ROM monitors.
1954 Various Renesas ROM monitors and debugging interfaces for SH and
1959 Support for a Macraigor serial interface to on-chip debugging.
1960 GDB does not directly support the newer parallel or USB
1965 A debug information format. The predecessor to DWARF 2 and
1966 DWARF 3, which are still supported.
1968 Support for the HP aCC compiler on HP-UX/PA-RISC
1970 SOM-encapsulated symbolic debugging information, automatic
1971 invocation of pxdb, and the aCC custom C++ ABI. This does not
1972 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1973 with aCC can still be debugged on an assembly level.
1975 MIPS ".pdr" sections
1977 A MIPS-specific format used to describe stack frame layout
1978 in debugging information.
1982 GDB could work with an older version of Guile to debug
1983 the interpreter and Scheme programs running in it.
1985 set mips stack-arg-size
1986 set mips saved-gpreg-size
1988 Use "set mips abi" to control parameter passing for MIPS.
1990 *** Changes in GDB 6.6
1995 Cell Broadband Engine SPU spu-elf
1997 * GDB can now be configured as a cross-debugger targeting native Windows
1998 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1999 running on a Windows system over TCP/IP to debug Windows programs.
2001 * The GDB remote stub, gdbserver, has been updated to support Windows and
2002 Cygwin debugging. Both single-threaded and multi-threaded programs are
2005 * The "set trust-readonly-sections" command works again. This command was
2006 broken in GDB 6.3, 6.4, and 6.5.
2008 * The "load" command now supports writing to flash memory, if the remote
2009 stub provides the required support.
2011 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2012 longer requires symbolic debug information (e.g. DWARF-2).
2017 unset substitute-path
2018 show substitute-path
2019 Manage a list of substitution rules that GDB uses to rewrite the name
2020 of the directories where the sources are located. This can be useful
2021 for instance when the sources were moved to a different location
2022 between compilation and debugging.
2026 Print each CLI command as it is executed. Each command is prefixed with
2027 a number of `+' symbols representing the nesting depth.
2028 The source command now has a `-v' option to enable the same feature.
2032 The ARM Demon monitor support (RDP protocol, "target rdp").
2034 Kernel Object Display, an embedded debugging feature which only worked with
2035 an obsolete version of Cisco IOS.
2037 The 'set download-write-size' and 'show download-write-size' commands.
2039 * New remote packets
2042 Tell a stub about GDB client features, and request remote target features.
2043 The first feature implemented is PacketSize, which allows the target to
2044 specify the size of packets it can handle - to minimize the number of
2045 packets required and improve performance when connected to a remote
2049 Fetch an OS auxilliary vector from the remote stub. This packet is a
2050 more efficient replacement for qPart:auxv:read.
2052 qXfer:memory-map:read:
2053 Fetch a memory map from the remote stub, including information about
2054 RAM, ROM, and flash memory devices.
2059 Erase and program a flash memory device.
2061 * Removed remote packets
2064 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2065 used it, and only gdbserver implemented it.
2067 *** Changes in GDB 6.5
2071 Renesas M32C/M16C m32c-elf
2073 Morpho Technologies ms1 ms1-elf
2077 init-if-undefined Initialize a convenience variable, but
2078 only if it doesn't already have a value.
2080 The following commands are presently only implemented for native GNU/Linux:
2082 checkpoint Save a snapshot of the program state.
2084 restart <n> Return the program state to a
2085 previously saved state.
2087 info checkpoints List currently saved checkpoints.
2089 delete-checkpoint <n> Delete a previously saved checkpoint.
2091 set|show detach-on-fork Tell gdb whether to detach from a newly
2092 forked process, or to keep debugging it.
2094 info forks List forks of the user program that
2095 are available to be debugged.
2097 fork <n> Switch to debugging one of several
2098 forks of the user program that are
2099 available to be debugged.
2101 delete-fork <n> Delete a fork from the list of forks
2102 that are available to be debugged (and
2103 kill the forked process).
2105 detach-fork <n> Delete a fork from the list of forks
2106 that are available to be debugged (and
2107 allow the process to continue).
2111 Morpho Technologies ms2 ms1-elf
2113 * Improved Windows host support
2115 GDB now builds as a cross debugger hosted on i686-mingw32, including
2116 native console support, and remote communications using either
2117 network sockets or serial ports.
2119 * Improved Modula-2 language support
2121 GDB can now print most types in the Modula-2 syntax. This includes:
2122 basic types, set types, record types, enumerated types, range types,
2123 pointer types and ARRAY types. Procedure var parameters are correctly
2124 printed and hexadecimal addresses and character constants are also
2125 written in the Modula-2 syntax. Best results can be obtained by using
2126 GNU Modula-2 together with the -gdwarf-2 command line option.
2130 The ARM rdi-share module.
2132 The Netware NLM debug server.
2134 *** Changes in GDB 6.4
2136 * New native configurations
2138 OpenBSD/arm arm*-*-openbsd*
2139 OpenBSD/mips64 mips64-*-openbsd*
2143 Morpho Technologies ms1 ms1-elf
2145 * New command line options
2147 --batch-silent As for --batch, but totally silent.
2148 --return-child-result The debugger will exist with the same value
2149 the child (debugged) program exited with.
2150 --eval-command COMMAND, -ex COMMAND
2151 Execute a single GDB CLI command. This may be
2152 specified multiple times and in conjunction
2153 with the --command (-x) option.
2155 * Deprecated commands removed
2157 The following commands, that were deprecated in 2000, have been
2161 set|show arm disassembly-flavor set|show arm disassembler
2162 othernames set arm disassembler
2163 set|show remotedebug set|show debug remote
2164 set|show archdebug set|show debug arch
2165 set|show eventdebug set|show debug event
2168 * New BSD user-level threads support
2170 It is now possible to debug programs using the user-level threads
2171 library on OpenBSD and FreeBSD. Currently supported (target)
2174 FreeBSD/amd64 x86_64-*-freebsd*
2175 FreeBSD/i386 i386-*-freebsd*
2176 OpenBSD/i386 i386-*-openbsd*
2178 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2179 are not yet supported.
2181 * New support for Matsushita MN10300 w/sim added
2182 (Work in progress). mn10300-elf.
2184 * REMOVED configurations and files
2186 VxWorks and the XDR protocol *-*-vxworks
2187 Motorola MCORE mcore-*-*
2188 National Semiconductor NS32000 ns32k-*-*
2190 * New "set print array-indexes" command
2192 After turning this setting "on", GDB prints the index of each element
2193 when displaying arrays. The default is "off" to preserve the previous
2196 * VAX floating point support
2198 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2200 * User-defined command support
2202 In addition to using $arg0..$arg9 for argument passing, it is now possible
2203 to use $argc to determine now many arguments have been passed. See the
2204 section on user-defined commands in the user manual for more information.
2206 *** Changes in GDB 6.3:
2208 * New command line option
2210 GDB now accepts -l followed by a number to set the timeout for remote
2213 * GDB works with GCC -feliminate-dwarf2-dups
2215 GDB now supports a more compact representation of DWARF-2 debug
2216 information using DW_FORM_ref_addr references. These are produced
2217 by GCC with the option -feliminate-dwarf2-dups and also by some
2218 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2219 to use -feliminate-dwarf2-dups.
2221 * Internationalization
2223 When supported by the host system, GDB will be built with
2224 internationalization (libintl). The task of marking up the sources is
2225 continued, we're looking forward to our first translation.
2229 Initial support for debugging programs compiled with the GNAT
2230 implementation of the Ada programming language has been integrated
2231 into GDB. In this release, support is limited to expression evaluation.
2233 * New native configurations
2235 GNU/Linux/m32r m32r-*-linux-gnu
2239 GDB's remote protocol now includes support for the 'p' packet. This
2240 packet is used to fetch individual registers from a remote inferior.
2242 * END-OF-LIFE registers[] compatibility module
2244 GDB's internal register infrastructure has been completely rewritten.
2245 The new infrastructure making possible the implementation of key new
2246 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2249 GDB 6.3 will be the last release to include the the registers[]
2250 compatibility module that allowed out-of-date configurations to
2251 continue to work. This change directly impacts the following
2261 powerpc bdm protocol
2263 Unless there is activity to revive these configurations, they will be
2264 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2266 * OBSOLETE configurations and files
2268 Configurations that have been declared obsolete in this release have
2269 been commented out. Unless there is activity to revive these
2270 configurations, the next release of GDB will have their sources
2271 permanently REMOVED.
2280 *** Changes in GDB 6.2.1:
2282 * MIPS `break main; run' gave an heuristic-fence-post warning
2284 When attempting to run even a simple program, a warning about
2285 heuristic-fence-post being hit would be reported. This problem has
2288 * MIPS IRIX 'long double' crashed GDB
2290 When examining a long double variable, GDB would get a segmentation
2291 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2292 IRIX long double values).
2296 A bug in the VAX stack code was causing problems with the "next"
2297 command. This problem has been fixed.
2299 *** Changes in GDB 6.2:
2301 * Fix for ``many threads''
2303 On GNU/Linux systems that use the NPTL threads library, a program
2304 rapidly creating and deleting threads would confuse GDB leading to the
2307 ptrace: No such process.
2308 thread_db_get_info: cannot get thread info: generic error
2310 This problem has been fixed.
2312 * "-async" and "-noasync" options removed.
2314 Support for the broken "-noasync" option has been removed (it caused
2317 * New ``start'' command.
2319 This command runs the program until the begining of the main procedure.
2321 * New BSD Kernel Data Access Library (libkvm) interface
2323 Using ``target kvm'' it is now possible to debug kernel core dumps and
2324 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2325 platforms. Currently supported (native-only) configurations are:
2327 FreeBSD/amd64 x86_64-*-freebsd*
2328 FreeBSD/i386 i?86-*-freebsd*
2329 NetBSD/i386 i?86-*-netbsd*
2330 NetBSD/m68k m68*-*-netbsd*
2331 NetBSD/sparc sparc-*-netbsd*
2332 OpenBSD/amd64 x86_64-*-openbsd*
2333 OpenBSD/i386 i?86-*-openbsd*
2334 OpenBSD/m68k m68*-openbsd*
2335 OpenBSD/sparc sparc-*-openbsd*
2337 * Signal trampoline code overhauled
2339 Many generic problems with GDB's signal handling code have been fixed.
2340 These include: backtraces through non-contiguous stacks; recognition
2341 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2342 call; backtrace through a signal trampoline; step into and out of
2343 signal handlers; and single-stepping in the signal trampoline.
2345 Please note that kernel bugs are a limiting factor here. These
2346 features have been shown to work on an s390 GNU/Linux system that
2347 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2349 * Cygwin support for DWARF 2 added.
2351 * New native configurations
2353 GNU/Linux/hppa hppa*-*-linux*
2354 OpenBSD/hppa hppa*-*-openbsd*
2355 OpenBSD/m68k m68*-*-openbsd*
2356 OpenBSD/m88k m88*-*-openbsd*
2357 OpenBSD/powerpc powerpc-*-openbsd*
2358 NetBSD/vax vax-*-netbsd*
2359 OpenBSD/vax vax-*-openbsd*
2361 * END-OF-LIFE frame compatibility module
2363 GDB's internal frame infrastructure has been completely rewritten.
2364 The new infrastructure making it possible to support key new features
2365 including DWARF 2 Call Frame Information. To aid in the task of
2366 migrating old configurations to this new infrastructure, a
2367 compatibility module, that allowed old configurations to continue to
2368 work, was also included.
2370 GDB 6.2 will be the last release to include this frame compatibility
2371 module. This change directly impacts the following configurations:
2381 Unless there is activity to revive these configurations, they will be
2382 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2384 * REMOVED configurations and files
2386 Sun 3, running SunOS 3 m68*-*-sunos3*
2387 Sun 3, running SunOS 4 m68*-*-sunos4*
2388 Sun 2, running SunOS 3 m68000-*-sunos3*
2389 Sun 2, running SunOS 4 m68000-*-sunos4*
2390 Motorola 680x0 running LynxOS m68*-*-lynxos*
2391 AT&T 3b1/Unix pc m68*-att-*
2392 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2393 decstation mips-dec-* mips-little-*
2394 riscos mips-*-riscos* mips-*-sysv*
2395 sonymips mips-sony-*
2396 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2398 *** Changes in GDB 6.1.1:
2400 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2402 The TUI (Text-mode User Interface) is now built as part of a default
2403 GDB configuration. It is enabled by either selecting the TUI with the
2404 command line option "-i=tui" or by running the separate "gdbtui"
2405 program. For more information on the TUI, see the manual "Debugging
2408 * Pending breakpoint support (also included in GDB 6.1)
2410 Support has been added to allow you to specify breakpoints in shared
2411 libraries that have not yet been loaded. If a breakpoint location
2412 cannot be found, and the "breakpoint pending" option is set to auto,
2413 GDB queries you if you wish to make the breakpoint pending on a future
2414 shared-library load. If and when GDB resolves the breakpoint symbol,
2415 the pending breakpoint is removed as one or more regular breakpoints
2418 Pending breakpoints are very useful for GCJ Java debugging.
2420 * Fixed ISO-C build problems
2422 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2423 non ISO-C code that stopped them being built using a more strict ISO-C
2424 compiler (e.g., IBM's C compiler).
2426 * Fixed build problem on IRIX 5
2428 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2429 wasn't able to compile compile on an IRIX 5 system.
2431 * Added execute permission to gdb/gdbserver/configure
2433 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2434 permission. This bug would cause configure to fail on a number of
2435 systems (Solaris, IRIX). Ref: server/519.
2437 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2439 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2440 has been updated to use constant array sizes.
2442 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2444 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2445 its generated DWARF Call Frame Info. This encoding was causing GDB to
2446 panic, that panic has been fixed. Ref: gdb/1628.
2448 * Fixed a problem when examining parameters in shared library code.
2450 When examining parameters in optimized shared library code generated
2451 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2452 not available''. GDB now correctly displays the variable's value.
2454 *** Changes in GDB 6.1:
2456 * Removed --with-mmalloc
2458 Support for the mmalloc memory manager has been removed, as it
2459 conflicted with the internal gdb byte cache.
2461 * Changes in AMD64 configurations
2463 The AMD64 target now includes the %cs and %ss registers. As a result
2464 the AMD64 remote protocol has changed; this affects the floating-point
2465 and SSE registers. If you rely on those registers for your debugging,
2466 you should upgrade gdbserver on the remote side.
2468 * Revised SPARC target
2470 The SPARC target has been completely revised, incorporating the
2471 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2472 support for LynxOS and SunOS 4 has been dropped. Calling functions
2473 from within GDB on operating systems with a non-executable stack
2474 (Solaris, OpenBSD) now works.
2478 GDB has a new C++ demangler which does a better job on the mangled
2479 names generated by current versions of g++. It also runs faster, so
2480 with this and other changes gdb should now start faster on large C++
2483 * DWARF 2 Location Expressions
2485 GDB support for location expressions has been extended to support function
2486 arguments and frame bases. Older versions of GDB could crash when they
2489 * C++ nested types and namespaces
2491 GDB's support for nested types and namespaces in C++ has been
2492 improved, especially if you use the DWARF 2 debugging format. (This
2493 is the default for recent versions of GCC on most platforms.)
2494 Specifically, if you have a class "Inner" defined within a class or
2495 namespace "Outer", then GDB realizes that the class's name is
2496 "Outer::Inner", not simply "Inner". This should greatly reduce the
2497 frequency of complaints about not finding RTTI symbols. In addition,
2498 if you are stopped at inside of a function defined within a namespace,
2499 GDB modifies its name lookup accordingly.
2501 * New native configurations
2503 NetBSD/amd64 x86_64-*-netbsd*
2504 OpenBSD/amd64 x86_64-*-openbsd*
2505 OpenBSD/alpha alpha*-*-openbsd*
2506 OpenBSD/sparc sparc-*-openbsd*
2507 OpenBSD/sparc64 sparc64-*-openbsd*
2509 * New debugging protocols
2511 M32R with SDI protocol m32r-*-elf*
2513 * "set prompt-escape-char" command deleted.
2515 The command "set prompt-escape-char" has been deleted. This command,
2516 and its very obscure effet on GDB's prompt, was never documented,
2517 tested, nor mentioned in the NEWS file.
2519 * OBSOLETE configurations and files
2521 Configurations that have been declared obsolete in this release have
2522 been commented out. Unless there is activity to revive these
2523 configurations, the next release of GDB will have their sources
2524 permanently REMOVED.
2526 Sun 3, running SunOS 3 m68*-*-sunos3*
2527 Sun 3, running SunOS 4 m68*-*-sunos4*
2528 Sun 2, running SunOS 3 m68000-*-sunos3*
2529 Sun 2, running SunOS 4 m68000-*-sunos4*
2530 Motorola 680x0 running LynxOS m68*-*-lynxos*
2531 AT&T 3b1/Unix pc m68*-att-*
2532 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2533 decstation mips-dec-* mips-little-*
2534 riscos mips-*-riscos* mips-*-sysv*
2535 sonymips mips-sony-*
2536 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2538 * REMOVED configurations and files
2540 SGI Irix-4.x mips-sgi-irix4 or iris4
2541 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2542 Z8000 simulator z8k-zilog-none or z8ksim
2543 Matsushita MN10200 w/simulator mn10200-*-*
2544 H8/500 simulator h8500-hitachi-hms or h8500hms
2545 HP/PA running BSD hppa*-*-bsd*
2546 HP/PA running OSF/1 hppa*-*-osf*
2547 HP/PA Pro target hppa*-*-pro*
2548 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2549 386BSD i[3456]86-*-bsd*
2550 Sequent family i[3456]86-sequent-sysv4*
2551 i[3456]86-sequent-sysv*
2552 i[3456]86-sequent-bsd*
2553 SPARC running LynxOS sparc-*-lynxos*
2554 SPARC running SunOS 4 sparc-*-sunos4*
2555 Tsqware Sparclet sparclet-*-*
2556 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2558 *** Changes in GDB 6.0:
2562 Support for debugging the Objective-C programming language has been
2563 integrated into GDB.
2565 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2567 DWARF 2's Call Frame Information makes available compiler generated
2568 information that more exactly describes the program's run-time stack.
2569 By using this information, GDB is able to provide more robust stack
2572 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2573 have been updated to use a new backtrace mechanism which includes
2574 DWARF 2 CFI support.
2578 GDB's remote protocol has been extended to include support for hosted
2579 file I/O (where the remote target uses GDB's file system). See GDB's
2580 remote protocol documentation for details.
2582 * All targets using the new architecture framework.
2584 All of GDB's targets have been updated to use the new internal
2585 architecture framework. The way is now open for future GDB releases
2586 to include cross-architecture native debugging support (i386 on amd64,
2589 * GNU/Linux's Thread Local Storage (TLS)
2591 GDB now includes support for for the GNU/Linux implementation of
2592 per-thread variables.
2594 * GNU/Linux's Native POSIX Thread Library (NPTL)
2596 GDB's thread code has been updated to work with either the new
2597 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2599 * Separate debug info.
2601 GDB, in conjunction with BINUTILS, now supports a mechanism for
2602 automatically loading debug information from a separate file. Instead
2603 of shipping full debug and non-debug versions of system libraries,
2604 system integrators can now instead ship just the stripped libraries
2605 and optional debug files.
2607 * DWARF 2 Location Expressions
2609 DWARF 2 Location Expressions allow the compiler to more completely
2610 describe the location of variables (even in optimized code) to the
2613 GDB now includes preliminary support for location expressions (support
2614 for DW_OP_piece is still missing).
2618 A number of long standing bugs that caused GDB to die while starting a
2619 Java application have been fixed. GDB's Java support is now
2620 considered "useable".
2622 * GNU/Linux support for fork, vfork, and exec.
2624 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2625 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2628 * GDB supports logging output to a file
2630 There are two new commands, "set logging" and "show logging", which can be
2631 used to capture GDB's output to a file.
2633 * The meaning of "detach" has changed for gdbserver
2635 The "detach" command will now resume the application, as documented. To
2636 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2639 * d10v, m68hc11 `regs' command deprecated
2641 The `info registers' command has been updated so that it displays the
2642 registers using a format identical to the old `regs' command.
2646 A new command, "maint set profile on/off", has been added. This command can
2647 be used to enable or disable profiling while running GDB, to profile a
2648 session or a set of commands. In addition there is a new configure switch,
2649 "--enable-profiling", which will cause GDB to be compiled with profiling
2650 data, for more informative profiling results.
2652 * Default MI syntax changed to "mi2".
2654 The default MI (machine interface) syntax, enabled by the command line
2655 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2656 "mi1", can be enabled by specifying the option "-i=mi1".
2658 Support for the original "mi0" syntax (included in GDB 5.0) has been
2661 Fix for gdb/192: removed extraneous space when displaying frame level.
2662 Fix for gdb/672: update changelist is now output in mi list format.
2663 Fix for gdb/702: a -var-assign that updates the value now shows up
2664 in a subsequent -var-update.
2666 * New native configurations.
2668 FreeBSD/amd64 x86_64-*-freebsd*
2670 * Multi-arched targets.
2672 HP/PA HPUX11 hppa*-*-hpux*
2673 Renesas M32R/D w/simulator m32r-*-elf*
2675 * OBSOLETE configurations and files
2677 Configurations that have been declared obsolete in this release have
2678 been commented out. Unless there is activity to revive these
2679 configurations, the next release of GDB will have their sources
2680 permanently REMOVED.
2682 Z8000 simulator z8k-zilog-none or z8ksim
2683 Matsushita MN10200 w/simulator mn10200-*-*
2684 H8/500 simulator h8500-hitachi-hms or h8500hms
2685 HP/PA running BSD hppa*-*-bsd*
2686 HP/PA running OSF/1 hppa*-*-osf*
2687 HP/PA Pro target hppa*-*-pro*
2688 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2689 Sequent family i[3456]86-sequent-sysv4*
2690 i[3456]86-sequent-sysv*
2691 i[3456]86-sequent-bsd*
2692 Tsqware Sparclet sparclet-*-*
2693 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2695 * REMOVED configurations and files
2698 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2699 IBM AIX PS/2 i[3456]86-*-aix
2700 i386 running Mach 3.0 i[3456]86-*-mach3*
2701 i386 running Mach i[3456]86-*-mach*
2702 i386 running OSF/1 i[3456]86-*osf1mk*
2703 HP/Apollo 68k Family m68*-apollo*-sysv*,
2705 m68*-hp-bsd*, m68*-hp-hpux*
2706 Argonaut Risc Chip (ARC) arc-*-*
2707 Mitsubishi D30V d30v-*-*
2708 Fujitsu FR30 fr30-*-elf*
2709 OS/9000 i[34]86-*-os9k
2710 I960 with MON960 i960-*-coff
2712 * MIPS $fp behavior changed
2714 The convenience variable $fp, for the MIPS, now consistently returns
2715 the address of the current frame's base. Previously, depending on the
2716 context, $fp could refer to either $sp or the current frame's base
2717 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2718 The GNU Source-Level Debugger''.
2720 *** Changes in GDB 5.3:
2722 * GNU/Linux shared library multi-threaded performance improved.
2724 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2725 `/proc', in preference to `ptrace' for memory reads. This may result
2726 in an improvement in the start-up time of multi-threaded, shared
2727 library applications when run under GDB. One GDB user writes: ``loads
2728 shared libs like mad''.
2730 * ``gdbserver'' now supports multi-threaded applications on some targets
2732 Support for debugging multi-threaded applications which use
2733 the GNU/Linux LinuxThreads package has been added for
2734 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2735 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2737 * GDB now supports C/C++ preprocessor macros.
2739 GDB now expands preprocessor macro invocations in C/C++ expressions,
2740 and provides various commands for showing macro definitions and how
2743 The new command `macro expand EXPRESSION' expands any macro
2744 invocations in expression, and shows the result.
2746 The new command `show macro MACRO-NAME' shows the definition of the
2747 macro named MACRO-NAME, and where it was defined.
2749 Most compilers don't include information about macros in the debugging
2750 information by default. In GCC 3.1, for example, you need to compile
2751 your program with the options `-gdwarf-2 -g3'. If the macro
2752 information is present in the executable, GDB will read it.
2754 * Multi-arched targets.
2756 DEC Alpha (partial) alpha*-*-*
2757 DEC VAX (partial) vax-*-*
2759 National Semiconductor NS32000 (partial) ns32k-*-*
2760 Motorola 68000 (partial) m68k-*-*
2761 Motorola MCORE mcore-*-*
2765 Fujitsu FRV architecture added by Red Hat frv*-*-*
2768 * New native configurations
2770 Alpha NetBSD alpha*-*-netbsd*
2771 SH NetBSD sh*-*-netbsdelf*
2772 MIPS NetBSD mips*-*-netbsd*
2773 UltraSPARC NetBSD sparc64-*-netbsd*
2775 * OBSOLETE configurations and files
2777 Configurations that have been declared obsolete in this release have
2778 been commented out. Unless there is activity to revive these
2779 configurations, the next release of GDB will have their sources
2780 permanently REMOVED.
2782 Mitsubishi D30V d30v-*-*
2783 OS/9000 i[34]86-*-os9k
2784 IBM AIX PS/2 i[3456]86-*-aix
2785 Fujitsu FR30 fr30-*-elf*
2786 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2787 Argonaut Risc Chip (ARC) arc-*-*
2788 i386 running Mach 3.0 i[3456]86-*-mach3*
2789 i386 running Mach i[3456]86-*-mach*
2790 i386 running OSF/1 i[3456]86-*osf1mk*
2791 HP/Apollo 68k Family m68*-apollo*-sysv*,
2793 m68*-hp-bsd*, m68*-hp-hpux*
2794 I960 with MON960 i960-*-coff
2796 * OBSOLETE languages
2798 CHILL, a Pascal like language used by telecommunications companies.
2800 * REMOVED configurations and files
2802 AMD 29k family via UDI a29k-amd-udi, udi29k
2803 A29K VxWorks a29k-*-vxworks
2804 AMD 29000 embedded, using EBMON a29k-none-none
2805 AMD 29000 embedded with COFF a29k-none-coff
2806 AMD 29000 embedded with a.out a29k-none-aout
2808 testsuite/gdb.hp/gdb.threads-hp/ directory
2810 * New command "set max-user-call-depth <nnn>"
2812 This command allows the user to limit the call depth of user-defined
2813 commands. The default is 1024.
2815 * Changes in FreeBSD/i386 native debugging.
2817 Support for the "generate-core-file" has been added.
2819 * New commands "dump", "append", and "restore".
2821 These commands allow data to be copied from target memory
2822 to a bfd-format or binary file (dump and append), and back
2823 from a file into memory (restore).
2825 * Improved "next/step" support on multi-processor Alpha Tru64.
2827 The previous single-step mechanism could cause unpredictable problems,
2828 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2829 of a software single-step mechanism prevents this.
2831 *** Changes in GDB 5.2.1:
2839 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2840 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2841 Fix, by Joel Brobecker imported from mainline.
2843 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2844 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2845 Fix, by Fred Fish, imported from mainline.
2847 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2848 Surprisingly enough, it works now.
2849 By Michal Ludvig, imported from mainline.
2851 i386 hardware watchpoint support:
2852 avoid misses on second run for some targets.
2853 By Pierre Muller, imported from mainline.
2855 *** Changes in GDB 5.2:
2857 * New command "set trust-readonly-sections on[off]".
2859 This command is a hint that tells gdb that read-only sections
2860 really are read-only (ie. that their contents will not change).
2861 In this mode, gdb will go to the object file rather than the
2862 target to read memory from read-only sections (such as ".text").
2863 This can be a significant performance improvement on some
2864 (notably embedded) targets.
2866 * New command "generate-core-file" (or "gcore").
2868 This new gdb command allows the user to drop a core file of the child
2869 process state at any time. So far it's been implemented only for
2870 GNU/Linux and Solaris, but should be relatively easily ported to other
2871 hosts. Argument is core file name (defaults to core.<pid>).
2873 * New command line option
2875 GDB now accepts --pid or -p followed by a process id.
2877 * Change in command line behavior -- corefiles vs. process ids.
2879 There is a subtle behavior in the way in which GDB handles
2880 command line arguments. The first non-flag argument is always
2881 a program to debug, but the second non-flag argument may either
2882 be a corefile or a process id. Previously, GDB would attempt to
2883 open the second argument as a corefile, and if that failed, would
2884 issue a superfluous error message and then attempt to attach it as
2885 a process. Now, if the second argument begins with a non-digit,
2886 it will be treated as a corefile. If it begins with a digit,
2887 GDB will attempt to attach it as a process, and if no such process
2888 is found, will then attempt to open it as a corefile.
2890 * Changes in ARM configurations.
2892 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2893 configuration is fully multi-arch.
2895 * New native configurations
2897 ARM NetBSD arm*-*-netbsd*
2898 x86 OpenBSD i[3456]86-*-openbsd*
2899 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2900 Sparc64 running FreeBSD sparc64-*-freebsd*
2904 Sanyo XStormy16 xstormy16-elf
2906 * OBSOLETE configurations and files
2908 Configurations that have been declared obsolete in this release have
2909 been commented out. Unless there is activity to revive these
2910 configurations, the next release of GDB will have their sources
2911 permanently REMOVED.
2913 AMD 29k family via UDI a29k-amd-udi, udi29k
2914 A29K VxWorks a29k-*-vxworks
2915 AMD 29000 embedded, using EBMON a29k-none-none
2916 AMD 29000 embedded with COFF a29k-none-coff
2917 AMD 29000 embedded with a.out a29k-none-aout
2919 testsuite/gdb.hp/gdb.threads-hp/ directory
2921 * REMOVED configurations and files
2923 TI TMS320C80 tic80-*-*
2925 PowerPC Solaris powerpcle-*-solaris*
2926 PowerPC Windows NT powerpcle-*-cygwin32
2927 PowerPC Netware powerpc-*-netware*
2928 Harris/CXUX m88k m88*-harris-cxux*
2929 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2930 ns32k-utek-sysv* ns32k-utek-*
2931 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2932 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2933 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2934 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2935 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2937 * Changes to command line processing
2939 The new `--args' feature can be used to specify command-line arguments
2940 for the inferior from gdb's command line.
2942 * Changes to key bindings
2944 There is a new `operate-and-get-next' function bound to `C-o'.
2946 *** Changes in GDB 5.1.1
2948 Fix compile problem on DJGPP.
2950 Fix a problem with floating-point registers on the i386 being
2953 Fix to stop GDB crashing on .debug_str debug info.
2955 Numerous documentation fixes.
2957 Numerous testsuite fixes.
2959 *** Changes in GDB 5.1:
2961 * New native configurations
2963 Alpha FreeBSD alpha*-*-freebsd*
2964 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2965 MIPS GNU/Linux mips*-*-linux*
2966 MIPS SGI Irix 6.x mips*-sgi-irix6*
2967 ia64 AIX ia64-*-aix*
2968 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2972 Motorola 68HC11 and 68HC12 m68hc11-elf
2974 UltraSparc running GNU/Linux sparc64-*-linux*
2976 * OBSOLETE configurations and files
2978 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2979 Harris/CXUX m88k m88*-harris-cxux*
2980 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2981 ns32k-utek-sysv* ns32k-utek-*
2982 TI TMS320C80 tic80-*-*
2984 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2985 PowerPC Solaris powerpcle-*-solaris*
2986 PowerPC Windows NT powerpcle-*-cygwin32
2987 PowerPC Netware powerpc-*-netware*
2988 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2989 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2990 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2991 Apple Macintosh (MPW) host N/A
2993 stuff.c (Program to stuff files into a specially prepared space in kdb)
2994 kdb-start.c (Main loop for the standalone kernel debugger)
2996 Configurations that have been declared obsolete in this release have
2997 been commented out. Unless there is activity to revive these
2998 configurations, the next release of GDB will have their sources
2999 permanently REMOVED.
3001 * REMOVED configurations and files
3003 Altos 3068 m68*-altos-*
3004 Convex c1-*-*, c2-*-*
3006 ARM RISCix arm-*-* (as host)
3010 * GDB has been converted to ISO C.
3012 GDB's source code has been converted to ISO C. In particular, the
3013 sources are fully protoized, and rely on standard headers being
3018 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3020 * The MI enabled by default.
3022 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3023 revised and enabled by default. Packages which use GDB as a debugging
3024 engine behind a UI or another front end are encouraged to switch to
3025 using the GDB/MI interface, instead of the old annotations interface
3026 which is now deprecated.
3028 * Support for debugging Pascal programs.
3030 GDB now includes support for debugging Pascal programs. The following
3031 main features are supported:
3033 - Pascal-specific data types such as sets;
3035 - automatic recognition of Pascal sources based on file-name
3038 - Pascal-style display of data types, variables, and functions;
3040 - a Pascal expression parser.
3042 However, some important features are not yet supported.
3044 - Pascal string operations are not supported at all;
3046 - there are some problems with boolean types;
3048 - Pascal type hexadecimal constants are not supported
3049 because they conflict with the internal variables format;
3051 - support for Pascal objects and classes is not full yet;
3053 - unlike Pascal, GDB is case-sensitive for symbol names.
3055 * Changes in completion.
3057 Commands such as `shell', `run' and `set args', which pass arguments
3058 to inferior programs, now complete on file names, similar to what
3059 users expect at the shell prompt.
3061 Commands which accept locations, such as `disassemble', `print',
3062 `breakpoint', `until', etc. now complete on filenames as well as
3063 program symbols. Thus, if you type "break foob TAB", and the source
3064 files linked into the programs include `foobar.c', that file name will
3065 be one of the candidates for completion. However, file names are not
3066 considered for completion after you typed a colon that delimits a file
3067 name from a name of a function in that file, as in "break foo.c:bar".
3069 `set demangle-style' completes on available demangling styles.
3071 * New platform-independent commands:
3073 It is now possible to define a post-hook for a command as well as a
3074 hook that runs before the command. For more details, see the
3075 documentation of `hookpost' in the GDB manual.
3077 * Changes in GNU/Linux native debugging.
3079 Support for debugging multi-threaded programs has been completely
3080 revised for all platforms except m68k and sparc. You can now debug as
3081 many threads as your system allows you to have.
3083 Attach/detach is supported for multi-threaded programs.
3085 Support for SSE registers was added for x86. This doesn't work for
3086 multi-threaded programs though.
3088 * Changes in MIPS configurations.
3090 Multi-arch support is enabled for all MIPS configurations.
3092 GDB can now be built as native debugger on SGI Irix 6.x systems for
3093 debugging n32 executables. (Debugging 64-bit executables is not yet
3096 * Unified support for hardware watchpoints in all x86 configurations.
3098 Most (if not all) native x86 configurations support hardware-assisted
3099 breakpoints and watchpoints in a unified manner. This support
3100 implements debug register sharing between watchpoints, which allows to
3101 put a virtually infinite number of watchpoints on the same address,
3102 and also supports watching regions up to 16 bytes with several debug
3105 The new maintenance command `maintenance show-debug-regs' toggles
3106 debugging print-outs in functions that insert, remove, and test
3107 watchpoints and hardware breakpoints.
3109 * Changes in the DJGPP native configuration.
3111 New command ``info dos sysinfo'' displays assorted information about
3112 the CPU, OS, memory, and DPMI server.
3114 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3115 display information about segment descriptors stored in GDT, LDT, and
3118 New commands ``info dos pde'' and ``info dos pte'' display entries
3119 from Page Directory and Page Tables (for now works with CWSDPMI only).
3120 New command ``info dos address-pte'' displays the Page Table entry for
3121 a given linear address.
3123 GDB can now pass command lines longer than 126 characters to the
3124 program being debugged (requires an update to the libdbg.a library
3125 which is part of the DJGPP development kit).
3127 DWARF2 debug info is now supported.
3129 It is now possible to `step' and `next' through calls to `longjmp'.
3131 * Changes in documentation.
3133 All GDB documentation was converted to GFDL, the GNU Free
3134 Documentation License.
3136 Tracepoints-related commands are now fully documented in the GDB
3139 TUI, the Text-mode User Interface, is now documented in the manual.
3141 Tracepoints-related commands are now fully documented in the GDB
3144 The "GDB Internals" manual now has an index. It also includes
3145 documentation of `ui_out' functions, GDB coding standards, x86
3146 hardware watchpoints, and memory region attributes.
3148 * GDB's version number moved to ``version.in''
3150 The Makefile variable VERSION has been replaced by the file
3151 ``version.in''. People creating GDB distributions should update the
3152 contents of this file.
3156 GUD support is now a standard part of the EMACS distribution.
3158 *** Changes in GDB 5.0:
3160 * Improved support for debugging FP programs on x86 targets
3162 Unified and much-improved support for debugging floating-point
3163 programs on all x86 targets. In particular, ``info float'' now
3164 displays the FP registers in the same format on all x86 targets, with
3165 greater level of detail.
3167 * Improvements and bugfixes in hardware-assisted watchpoints
3169 It is now possible to watch array elements, struct members, and
3170 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3171 on x86 targets no longer erroneously trigger when the address is
3174 * Improvements in the native DJGPP version of GDB
3176 The distribution now includes all the scripts and auxiliary files
3177 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3178 machines ``out of the box''.
3180 The DJGPP version can now debug programs that use signals. It is
3181 possible to catch signals that happened in the debuggee, deliver
3182 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3183 would kill the program being debugged.) Programs that hook hardware
3184 interrupts (keyboard, timer, etc.) can also be debugged.
3186 It is now possible to debug DJGPP programs that redirect their
3187 standard handles or switch them to raw (as opposed to cooked) mode, or
3188 even close them. The command ``run < foo > bar'' works as expected,
3189 and ``info terminal'' reports useful information about the debuggee's
3190 terminal, including raw/cooked mode, redirection, etc.
3192 The DJGPP version now uses termios functions for console I/O, which
3193 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3196 DOS-style file names with drive letters are now fully supported by
3199 It is now possible to debug DJGPP programs that switch their working
3200 directory. It is also possible to rerun the debuggee any number of
3201 times without restarting GDB; thus, you can use the same setup,
3202 breakpoints, etc. for many debugging sessions.
3204 * New native configurations
3206 ARM GNU/Linux arm*-*-linux*
3207 PowerPC GNU/Linux powerpc-*-linux*
3211 Motorola MCore mcore-*-*
3212 x86 VxWorks i[3456]86-*-vxworks*
3213 PowerPC VxWorks powerpc-*-vxworks*
3214 TI TMS320C80 tic80-*-*
3216 * OBSOLETE configurations
3218 Altos 3068 m68*-altos-*
3219 Convex c1-*-*, c2-*-*
3221 ARM RISCix arm-*-* (as host)
3224 Configurations that have been declared obsolete will be commented out,
3225 but the code will be left in place. If there is no activity to revive
3226 these configurations before the next release of GDB, the sources will
3227 be permanently REMOVED.
3229 * Gould support removed
3231 Support for the Gould PowerNode and NP1 has been removed.
3233 * New features for SVR4
3235 On SVR4 native platforms (such as Solaris), if you attach to a process
3236 without first loading a symbol file, GDB will now attempt to locate and
3237 load symbols from the running process's executable file.
3239 * Many C++ enhancements
3241 C++ support has been greatly improved. Overload resolution now works properly
3242 in almost all cases. RTTI support is on the way.
3244 * Remote targets can connect to a sub-program
3246 A popen(3) style serial-device has been added. This device starts a
3247 sub-process (such as a stand-alone simulator) and then communicates
3248 with that. The sub-program to run is specified using the syntax
3249 ``|<program> <args>'' vis:
3251 (gdb) set remotedebug 1
3252 (gdb) target extended-remote |mn10300-elf-sim program-args
3254 * MIPS 64 remote protocol
3256 A long standing bug in the mips64 remote protocol where by GDB
3257 expected certain 32 bit registers (ex SR) to be transfered as 32
3258 instead of 64 bits has been fixed.
3260 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3261 added to provide backward compatibility with older versions of GDB.
3263 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3265 The command ``set remotebinarydownload'' command has been replaced by
3266 ``set remote X-packet''. Other commands in ``set remote'' family
3267 include ``set remote P-packet''.
3269 * Breakpoint commands accept ranges.
3271 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3272 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3273 ``tracepoint passcount'' also accepts a range of tracepoints.
3275 * ``apropos'' command added.
3277 The ``apropos'' command searches through command names and
3278 documentation strings, printing out matches, making it much easier to
3279 try to find a command that does what you are looking for.
3283 A new machine oriented interface (MI) has been added to GDB. This
3284 interface is designed for debug environments running GDB as a separate
3285 process. This is part of the long term libGDB project. See the
3286 "GDB/MI" chapter of the GDB manual for further information. It can be
3287 enabled by configuring with:
3289 .../configure --enable-gdbmi
3291 *** Changes in GDB-4.18:
3293 * New native configurations
3295 HP-UX 10.20 hppa*-*-hpux10.20
3296 HP-UX 11.x hppa*-*-hpux11.0*
3297 M68K GNU/Linux m68*-*-linux*
3301 Fujitsu FR30 fr30-*-elf*
3302 Intel StrongARM strongarm-*-*
3303 Mitsubishi D30V d30v-*-*
3305 * OBSOLETE configurations
3307 Gould PowerNode, NP1 np1-*-*, pn-*-*
3309 Configurations that have been declared obsolete will be commented out,
3310 but the code will be left in place. If there is no activity to revive
3311 these configurations before the next release of GDB, the sources will
3312 be permanently REMOVED.
3316 As a compatibility experiment, GDB's source files buildsym.h and
3317 buildsym.c have been converted to pure standard C, no longer
3318 containing any K&R compatibility code. We believe that all systems in
3319 use today either come with a standard C compiler, or have a GCC port
3320 available. If this is not true, please report the affected
3321 configuration to bug-gdb@gnu.org immediately. See the README file for
3322 information about getting a standard C compiler if you don't have one
3327 GDB now uses readline 2.2.
3329 * set extension-language
3331 You can now control the mapping between filename extensions and source
3332 languages by using the `set extension-language' command. For instance,
3333 you can ask GDB to treat .c files as C++ by saying
3334 set extension-language .c c++
3335 The command `info extensions' lists all of the recognized extensions
3336 and their associated languages.
3338 * Setting processor type for PowerPC and RS/6000
3340 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3341 you can use the `set processor' command to specify what variant of the
3342 PowerPC family you are debugging. The command
3346 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3347 following PowerPC and RS6000 variants:
3349 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3350 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3352 403GC IBM PowerPC 403GC
3353 505 Motorola PowerPC 505
3354 860 Motorola PowerPC 860 or 850
3355 601 Motorola PowerPC 601
3356 602 Motorola PowerPC 602
3357 603 Motorola/IBM PowerPC 603 or 603e
3358 604 Motorola PowerPC 604 or 604e
3359 750 Motorola/IBM PowerPC 750 or 750
3361 At the moment, this command just tells GDB what to name the
3362 special-purpose processor registers. Since almost all the affected
3363 registers are inaccessible to user-level programs, this command is
3364 only useful for remote debugging in its present form.
3368 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3369 more extensive support for HP-UX. Added features include shared
3370 library support, kernel threads and hardware watchpoints for 11.00,
3371 support for HP's ANSI C and C++ compilers, and a compatibility mode
3372 for xdb and dbx commands.
3376 HP's donation includes the new concept of catchpoints, which is a
3377 generalization of the old catch command. On HP-UX, it is now possible
3378 to catch exec, fork, and vfork, as well as library loading.
3380 This means that the existing catch command has changed; its first
3381 argument now specifies the type of catch to be set up. See the
3382 output of "help catch" for a list of catchpoint types.
3384 * Debugging across forks
3386 On HP-UX, you can choose which process to debug when a fork() happens
3391 HP has donated a curses-based terminal user interface (TUI). To get
3392 it, build with --enable-tui. Although this can be enabled for any
3393 configuration, at present it only works for native HP debugging.
3395 * GDB remote protocol additions
3397 A new protocol packet 'X' that writes binary data is now available.
3398 Default behavior is to try 'X', then drop back to 'M' if the stub
3399 fails to respond. The settable variable `remotebinarydownload'
3400 allows explicit control over the use of 'X'.
3402 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3403 full 64-bit address. The command
3405 set remoteaddresssize 32
3407 can be used to revert to the old behaviour. For existing remote stubs
3408 the change should not be noticed, as the additional address information
3411 In order to assist in debugging stubs, you may use the maintenance
3412 command `packet' to send any text string to the stub. For instance,
3414 maint packet heythere
3416 sends the packet "$heythere#<checksum>". Note that it is very easy to
3417 disrupt a debugging session by sending the wrong packet at the wrong
3420 The compare-sections command allows you to compare section data on the
3421 target to what is in the executable file without uploading or
3422 downloading, by comparing CRC checksums.
3424 * Tracing can collect general expressions
3426 You may now collect general expressions at tracepoints. This requires
3427 further additions to the target-side stub; see tracepoint.c and
3428 doc/agentexpr.texi for further details.
3430 * mask-address variable for Mips
3432 For Mips targets, you may control the zeroing of the upper 32 bits of
3433 a 64-bit address by entering `set mask-address on'. This is mainly
3434 of interest to users of embedded R4xxx and R5xxx processors.
3436 * Higher serial baud rates
3438 GDB's serial code now allows you to specify baud rates 57600, 115200,
3439 230400, and 460800 baud. (Note that your host system may not be able
3440 to achieve all of these rates.)
3444 The i960 configuration now includes an initial implementation of a
3445 builtin simulator, contributed by Jim Wilson.
3448 *** Changes in GDB-4.17:
3450 * New native configurations
3452 Alpha GNU/Linux alpha*-*-linux*
3453 Unixware 2.x i[3456]86-unixware2*
3454 Irix 6.x mips*-sgi-irix6*
3455 PowerPC GNU/Linux powerpc-*-linux*
3456 PowerPC Solaris powerpcle-*-solaris*
3457 Sparc GNU/Linux sparc-*-linux*
3458 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3462 Argonaut Risc Chip (ARC) arc-*-*
3463 Hitachi H8/300S h8300*-*-*
3464 Matsushita MN10200 w/simulator mn10200-*-*
3465 Matsushita MN10300 w/simulator mn10300-*-*
3466 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3467 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3468 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3469 Mitsubishi D10V w/simulator d10v-*-*
3470 Mitsubishi M32R/D w/simulator m32r-*-elf*
3471 Tsqware Sparclet sparclet-*-*
3472 NEC V850 w/simulator v850-*-*
3474 * New debugging protocols
3476 ARM with RDI protocol arm*-*-*
3477 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3478 DDB and LSI variants of PMON protocol mips*-*-*
3479 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3480 PowerPC with SDS protocol powerpc{,le}-*-eabi
3481 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3485 All configurations can now understand and use the DWARF 2 debugging
3486 format. The choice is automatic, if the symbol file contains DWARF 2
3491 GDB now includes basic Java language support. This support is
3492 only useful with Java compilers that produce native machine code.
3494 * solib-absolute-prefix and solib-search-path
3496 For SunOS and SVR4 shared libraries, you may now set the prefix for
3497 loading absolute shared library symbol files, and the search path for
3498 locating non-absolute shared library symbol files.
3500 * Live range splitting
3502 GDB can now effectively debug code for which GCC has performed live
3503 range splitting as part of its optimization. See gdb/doc/LRS for
3504 more details on the expected format of the stabs information.
3508 GDB's support for the GNU Hurd, including thread debugging, has been
3509 updated to work with current versions of the Hurd.
3513 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3514 instruction set. ARM GDB automatically detects when Thumb
3515 instructions are in use, and adjusts disassembly and backtracing
3520 GDB's MIPS target configurations now handle the MIP16 16-bit
3525 GDB now includes support for overlays; if an executable has been
3526 linked such that multiple sections are based at the same address, GDB
3527 will decide which section to use for symbolic info. You can choose to
3528 control the decision manually, using overlay commands, or implement
3529 additional target-side support and use "overlay load-target" to bring
3530 in the overlay mapping. Do "help overlay" for more detail.
3534 The command "info symbol <address>" displays information about
3535 the symbol at the specified address.
3539 The standard remote protocol now includes an extension that allows
3540 asynchronous collection and display of trace data. This requires
3541 extensive support in the target-side debugging stub. Tracing mode
3542 includes a new interaction mode in GDB and new commands: see the
3543 file tracepoint.c for more details.
3547 Configurations for embedded MIPS now include a simulator contributed
3548 by Cygnus Solutions. The simulator supports the instruction sets
3549 of most MIPS variants.
3553 Sparc configurations may now include the ERC32 simulator contributed
3554 by the European Space Agency. The simulator is not built into
3555 Sparc targets by default; configure with --enable-sim to include it.
3559 For target configurations that may include multiple variants of a
3560 basic architecture (such as MIPS and SH), you may now set the
3561 architecture explicitly. "set arch" sets, "info arch" lists
3562 the possible architectures.
3564 *** Changes in GDB-4.16:
3566 * New native configurations
3568 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3569 M68K NetBSD m68k-*-netbsd*
3570 PowerPC AIX 4.x powerpc-*-aix*
3571 PowerPC MacOS powerpc-*-macos*
3572 PowerPC Windows NT powerpcle-*-cygwin32
3573 RS/6000 AIX 4.x rs6000-*-aix4*
3577 ARM with RDP protocol arm-*-*
3578 I960 with MON960 i960-*-coff
3579 MIPS VxWorks mips*-*-vxworks*
3580 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3581 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3583 Matra Sparclet sparclet-*-*
3587 The powerpc-eabi configuration now includes the PSIM simulator,
3588 contributed by Andrew Cagney, with assistance from Mike Meissner.
3589 PSIM is a very elaborate model of the PowerPC, including not only
3590 basic instruction set execution, but also details of execution unit
3591 performance and I/O hardware. See sim/ppc/README for more details.
3595 GDB now works with Solaris 2.5.
3597 * Windows 95/NT native
3599 GDB will now work as a native debugger on Windows 95 and Windows NT.
3600 To build it from source, you must use the "gnu-win32" environment,
3601 which uses a DLL to emulate enough of Unix to run the GNU tools.
3602 Further information, binaries, and sources are available at
3603 ftp.cygnus.com, under pub/gnu-win32.
3605 * dont-repeat command
3607 If a user-defined command includes the command `dont-repeat', then the
3608 command will not be repeated if the user just types return. This is
3609 useful if the command is time-consuming to run, so that accidental
3610 extra keystrokes don't run the same command many times.
3612 * Send break instead of ^C
3614 The standard remote protocol now includes an option to send a break
3615 rather than a ^C to the target in order to interrupt it. By default,
3616 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3618 * Remote protocol timeout
3620 The standard remote protocol includes a new variable `remotetimeout'
3621 that allows you to set the number of seconds before GDB gives up trying
3622 to read from the target. The default value is 2.
3624 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3626 By default GDB will automatically keep track of objects as they are
3627 loaded and unloaded by the dynamic linker. By using the command `set
3628 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3629 when shared library events occur, thus allowing you to set breakpoints
3630 in shared libraries which are explicitly loaded by the inferior.
3632 Note this feature does not work on hpux8. On hpux9 you must link
3633 /usr/lib/end.o into your program. This feature should work
3634 automatically on hpux10.
3636 * Irix 5.x hardware watchpoint support
3638 Irix 5 configurations now support the use of hardware watchpoints.
3640 * Mips protocol "SYN garbage limit"
3642 When debugging a Mips target using the `target mips' protocol, you
3643 may set the number of characters that GDB will ignore by setting
3644 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3645 every character. The default value is 1050.
3647 * Recording and replaying remote debug sessions
3649 If you set `remotelogfile' to the name of a file, gdb will write to it
3650 a recording of a remote debug session. This recording may then be
3651 replayed back to gdb using "gdbreplay". See gdbserver/README for
3652 details. This is useful when you have a problem with GDB while doing
3653 remote debugging; you can make a recording of the session and send it
3654 to someone else, who can then recreate the problem.
3656 * Speedups for remote debugging
3658 GDB includes speedups for downloading and stepping MIPS systems using
3659 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3660 and more efficient S-record downloading.
3662 * Memory use reductions and statistics collection
3664 GDB now uses less memory and reports statistics about memory usage.
3665 Try the `maint print statistics' command, for example.
3667 *** Changes in GDB-4.15:
3669 * Psymtabs for XCOFF
3671 The symbol reader for AIX GDB now uses partial symbol tables. This
3672 can greatly improve startup time, especially for large executables.
3674 * Remote targets use caching
3676 Remote targets now use a data cache to speed up communication with the
3677 remote side. The data cache could lead to incorrect results because
3678 it doesn't know about volatile variables, thus making it impossible to
3679 debug targets which use memory mapped I/O devices. `set remotecache
3680 off' turns the the data cache off.
3682 * Remote targets may have threads
3684 The standard remote protocol now includes support for multiple threads
3685 in the target system, using new protocol commands 'H' and 'T'. See
3686 gdb/remote.c for details.
3690 If GDB is configured with `--enable-netrom', then it will include
3691 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3692 acts as though it is a bank of ROM on the target board, but you can
3693 write into it over the network. GDB's support consists only of
3694 support for fast loading into the emulated ROM; to debug, you must use
3695 another protocol, such as standard remote protocol. The usual
3696 sequence is something like
3698 target nrom <netrom-hostname>
3700 target remote <netrom-hostname>:1235
3704 GDB now includes support for the Apple Macintosh, as a host only. It
3705 may be run as either an MPW tool or as a standalone application, and
3706 it can debug through the serial port. All the usual GDB commands are
3707 available, but to the target command, you must supply "serial" as the
3708 device type instead of "/dev/ttyXX". See mpw-README in the main
3709 directory for more information on how to build. The MPW configuration
3710 scripts */mpw-config.in support only a few targets, and only the
3711 mips-idt-ecoff target has been tested.
3715 GDB configuration now uses autoconf. This is not user-visible,
3716 but does simplify configuration and building.
3720 GDB now supports hpux10.
3722 *** Changes in GDB-4.14:
3724 * New native configurations
3726 x86 FreeBSD i[345]86-*-freebsd
3727 x86 NetBSD i[345]86-*-netbsd
3728 NS32k NetBSD ns32k-*-netbsd
3729 Sparc NetBSD sparc-*-netbsd
3733 A29K VxWorks a29k-*-vxworks
3734 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3735 CPU32 EST-300 emulator m68*-*-est*
3736 PowerPC ELF powerpc-*-elf
3739 * Alpha OSF/1 support for procfs
3741 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3742 possible to attach to running processes. As the mounting of the /proc
3743 filesystem is optional on the Alpha, GDB automatically determines
3744 the availability of /proc during startup. This can lead to problems
3745 if /proc is unmounted after GDB has been started.
3747 * Arguments to user-defined commands
3749 User commands may accept up to 10 arguments separated by whitespace.
3750 Arguments are accessed within the user command via $arg0..$arg9. A
3753 print $arg0 + $arg1 + $arg2
3755 To execute the command use:
3758 Defines the command "adder" which prints the sum of its three arguments.
3759 Note the arguments are text substitutions, so they may reference variables,
3760 use complex expressions, or even perform inferior function calls.
3762 * New `if' and `while' commands
3764 This makes it possible to write more sophisticated user-defined
3765 commands. Both commands take a single argument, which is the
3766 expression to evaluate, and must be followed by the commands to
3767 execute, one per line, if the expression is nonzero, the list being
3768 terminated by the word `end'. The `if' command list may include an
3769 `else' word, which causes the following commands to be executed only
3770 if the expression is zero.
3772 * Fortran source language mode
3774 GDB now includes partial support for Fortran 77. It will recognize
3775 Fortran programs and can evaluate a subset of Fortran expressions, but
3776 variables and functions may not be handled correctly. GDB will work
3777 with G77, but does not yet know much about symbols emitted by other
3780 * Better HPUX support
3782 Most debugging facilities now work on dynamic executables for HPPAs
3783 running hpux9 or later. You can attach to running dynamically linked
3784 processes, but by default the dynamic libraries will be read-only, so
3785 for instance you won't be able to put breakpoints in them. To change
3786 that behavior do the following before running the program:
3792 This will cause the libraries to be mapped private and read-write.
3793 To revert to the normal behavior, do this:
3799 You cannot set breakpoints or examine data in the library until after
3800 the library is loaded if the function/data symbols do not have
3803 GDB can now also read debug symbols produced by the HP C compiler on
3804 HPPAs (sorry, no C++, Fortran or 68k support).
3806 * Target byte order now dynamically selectable
3808 You can choose which byte order to use with a target system, via the
3809 commands "set endian big" and "set endian little", and you can see the
3810 current setting by using "show endian". You can also give the command
3811 "set endian auto", in which case GDB will use the byte order
3812 associated with the executable. Currently, only embedded MIPS
3813 configurations support dynamic selection of target byte order.
3815 * New DOS host serial code
3817 This version uses DPMI interrupts to handle buffered I/O, so you
3818 no longer need to run asynctsr when debugging boards connected to
3821 *** Changes in GDB-4.13:
3823 * New "complete" command
3825 This lists all the possible completions for the rest of the line, if it
3826 were to be given as a command itself. This is intended for use by emacs.
3828 * Trailing space optional in prompt
3830 "set prompt" no longer adds a space for you after the prompt you set. This
3831 allows you to set a prompt which ends in a space or one that does not.
3833 * Breakpoint hit counts
3835 "info break" now displays a count of the number of times the breakpoint
3836 has been hit. This is especially useful in conjunction with "ignore"; you
3837 can ignore a large number of breakpoint hits, look at the breakpoint info
3838 to see how many times the breakpoint was hit, then run again, ignoring one
3839 less than that number, and this will get you quickly to the last hit of
3842 * Ability to stop printing at NULL character
3844 "set print null-stop" will cause GDB to stop printing the characters of
3845 an array when the first NULL is encountered. This is useful when large
3846 arrays actually contain only short strings.
3848 * Shared library breakpoints
3850 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3851 breakpoints in shared libraries before the executable is run.
3853 * Hardware watchpoints
3855 There is a new hardware breakpoint for the watch command for sparclite
3856 targets. See gdb/sparclite/hw_breakpoint.note.
3858 Hardware watchpoints are also now supported under GNU/Linux.
3862 Annotations have been added. These are for use with graphical interfaces,
3863 and are still experimental. Currently only gdba.el uses these.
3865 * Improved Irix 5 support
3867 GDB now works properly with Irix 5.2.
3869 * Improved HPPA support
3871 GDB now works properly with the latest GCC and GAS.
3873 * New native configurations
3875 Sequent PTX4 i[34]86-sequent-ptx4
3876 HPPA running OSF/1 hppa*-*-osf*
3877 Atari TT running SVR4 m68*-*-sysv4*
3878 RS/6000 LynxOS rs6000-*-lynxos*
3882 OS/9000 i[34]86-*-os9k
3883 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3886 * Hitachi SH7000 and E7000-PC ICE support
3888 There is now support for communicating with the Hitachi E7000-PC ICE.
3889 This is available automatically when GDB is configured for the SH.
3893 As usual, a variety of small fixes and improvements, both generic
3894 and configuration-specific. See the ChangeLog for more detail.
3896 *** Changes in GDB-4.12:
3898 * Irix 5 is now supported
3902 GDB-4.12 on the HPPA has a number of changes which make it unable
3903 to debug the output from the currently released versions of GCC and
3904 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3905 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3906 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3909 *** Changes in GDB-4.11:
3911 * User visible changes:
3915 The "set remotedebug" option is now consistent between the mips remote
3916 target, remote targets using the gdb-specific protocol, UDI (AMD's
3917 debug protocol for the 29k) and the 88k bug monitor. It is now an
3918 integer specifying a debug level (normally 0 or 1, but 2 means more
3919 debugging info for the mips target).
3921 * DEC Alpha native support
3923 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3924 debug info, but GDB works fairly well with the DEC compiler and should
3925 work with a future GCC release. See the README file for a few
3926 Alpha-specific notes.
3928 * Preliminary thread implementation
3930 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3932 * LynxOS native and target support for 386
3934 This release has been hosted on LynxOS 2.2, and also can be configured
3935 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3938 * Improvements in C++ mangling/demangling.
3940 This release has much better g++ debugging, specifically in name
3941 mangling/demangling, virtual function calls, print virtual table,
3942 call methods, ...etc.
3944 *** Changes in GDB-4.10:
3946 * User visible changes:
3948 Remote debugging using the GDB-specific (`target remote') protocol now
3949 supports the `load' command. This is only useful if you have some
3950 other way of getting the stub to the target system, and you can put it
3951 somewhere in memory where it won't get clobbered by the download.
3953 Filename completion now works.
3955 When run under emacs mode, the "info line" command now causes the
3956 arrow to point to the line specified. Also, "info line" prints
3957 addresses in symbolic form (as well as hex).
3959 All vxworks based targets now support a user settable option, called
3960 vxworks-timeout. This option represents the number of seconds gdb
3961 should wait for responses to rpc's. You might want to use this if
3962 your vxworks target is, perhaps, a slow software simulator or happens
3963 to be on the far side of a thin network line.
3967 This release contains support for using a DEC alpha as a GDB host for
3968 cross debugging. Native alpha debugging is not supported yet.
3971 *** Changes in GDB-4.9:
3975 This is the first GDB release which is accompanied by a matching testsuite.
3976 The testsuite requires installation of dejagnu, which should be available
3977 via ftp from most sites that carry GNU software.
3981 'Cfront' style demangling has had its name changed to 'ARM' style, to
3982 emphasize that it was written from the specifications in the C++ Annotated
3983 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3984 disclaimers, it still generated too much confusion with users attempting to
3985 use gdb with AT&T cfront.
3989 GDB now uses a standard remote interface to a simulator library.
3990 So far, the library contains simulators for the Zilog Z8001/2, the
3991 Hitachi H8/300, H8/500 and Super-H.
3993 * New targets supported
3995 H8/300 simulator h8300-hitachi-hms or h8300hms
3996 H8/500 simulator h8500-hitachi-hms or h8500hms
3997 SH simulator sh-hitachi-hms or sh
3998 Z8000 simulator z8k-zilog-none or z8ksim
3999 IDT MIPS board over serial line mips-idt-ecoff
4001 Cross-debugging to GO32 targets is supported. It requires a custom
4002 version of the i386-stub.c module which is integrated with the
4003 GO32 memory extender.
4005 * New remote protocols
4007 MIPS remote debugging protocol.
4009 * New source languages supported
4011 This version includes preliminary support for Chill, a Pascal like language
4012 used by telecommunications companies. Chill support is also being integrated
4013 into the GNU compiler, but we don't know when it will be publically available.
4016 *** Changes in GDB-4.8:
4018 * HP Precision Architecture supported
4020 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4021 version of this support was available as a set of patches from the
4022 University of Utah. GDB does not support debugging of programs
4023 compiled with the HP compiler, because HP will not document their file
4024 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4025 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4027 Many problems in the preliminary version have been fixed.
4029 * Faster and better demangling
4031 We have improved template demangling and fixed numerous bugs in the GNU style
4032 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4033 character types (wchar_t) are now supported. Demangling of each symbol is now
4034 only done once, and is cached when the symbol table for a file is read in.
4035 This results in a small increase in memory usage for C programs, a moderate
4036 increase in memory usage for C++ programs, and a fantastic speedup in
4039 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4040 from the specifications in the Annotated Reference Manual, which AT&T's
4041 compiler does not actually implement.
4043 * G++ multiple inheritance compiler problem
4045 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4046 inheritance lattices was reworked to properly discover ambiguities. We
4047 recently found an example which causes this new algorithm to fail in a
4048 very subtle way, producing bad debug information for those classes.
4049 The file 'gcc.patch' (in this directory) can be applied to gcc to
4050 circumvent the problem. A future GCC release will contain a complete
4053 The previous G++ debug info problem (mentioned below for the gdb-4.7
4054 release) is fixed in gcc version 2.3.2.
4056 * Improved configure script
4058 The `configure' script will now attempt to guess your system type if
4059 you don't supply a host system type. The old scheme of supplying a
4060 host system triplet is preferable over using this. All the magic is
4061 done in the new `config.guess' script. Examine it for details.
4063 We have also brought our configure script much more in line with the FSF's
4064 version. It now supports the --with-xxx options. In particular,
4065 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4066 The resulting GDB will not be able to read arbitrary object file formats --
4067 only the format ``expected'' to be used on the configured target system.
4068 We hope to make this the default in a future release.
4070 * Documentation improvements
4072 There's new internal documentation on how to modify GDB, and how to
4073 produce clean changes to the code. We implore people to read it
4074 before submitting changes.
4076 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4077 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4078 `info' files are also provided. To build `info' files from scratch,
4079 you will need the latest `makeinfo' release, which will be available in
4080 a future texinfo-X.Y release.
4082 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4083 We're not sure exactly which versions have this problem, but it has
4084 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4085 or better. If that isn't possible, there is a patch in
4086 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4087 around this problem.
4091 GDB now supports array constants that can be used in expressions typed in by
4092 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4093 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4096 The new directory `gdb/sparclite' contains a program that demonstrates
4097 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4099 * New native hosts supported
4101 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4102 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4104 * New targets supported
4106 AMD 29k family via UDI a29k-amd-udi or udi29k
4108 * New file formats supported
4110 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4111 HPUX core files, and SCO 3.2v2 core files.
4115 Attaching to processes now works again; thanks for the many bug reports.
4117 We have also stomped on a bunch of core dumps caused by
4118 printf_filtered("%s") problems.
4120 We eliminated a copyright problem on the rpc and ptrace header files
4121 for VxWorks, which was discovered at the last minute during the 4.7
4122 release. You should now be able to build a VxWorks GDB.
4124 You can now interrupt gdb while an attached process is running. This
4125 will cause the attached process to stop, and give control back to GDB.
4127 We fixed problems caused by using too many file descriptors
4128 for reading symbols from object files and libraries. This was
4129 especially a problem for programs that used many (~100) shared
4132 The `step' command now only enters a subroutine if there is line number
4133 information for the subroutine. Otherwise it acts like the `next'
4134 command. Previously, `step' would enter subroutines if there was
4135 any debugging information about the routine. This avoids problems
4136 when using `cc -g1' on MIPS machines.
4138 * Internal improvements
4140 GDB's internal interfaces have been improved to make it easier to support
4141 debugging of multiple languages in the future.
4143 GDB now uses a common structure for symbol information internally.
4144 Minimal symbols (derived from linkage symbols in object files), partial
4145 symbols (from a quick scan of debug information), and full symbols
4146 contain a common subset of information, making it easier to write
4147 shared code that handles any of them.
4149 * New command line options
4151 We now accept --silent as an alias for --quiet.
4155 The memory-mapped-malloc library is now licensed under the GNU Library
4156 General Public License.
4158 *** Changes in GDB-4.7:
4160 * Host/native/target split
4162 GDB has had some major internal surgery to untangle the support for
4163 hosts and remote targets. Now, when you configure GDB for a remote
4164 target, it will no longer load in all of the support for debugging
4165 local programs on the host. When fully completed and tested, this will
4166 ensure that arbitrary host/target combinations are possible.
4168 The primary conceptual shift is to separate the non-portable code in
4169 GDB into three categories. Host specific code is required any time GDB
4170 is compiled on that host, regardless of the target. Target specific
4171 code relates to the peculiarities of the target, but can be compiled on
4172 any host. Native specific code is everything else: it can only be
4173 built when the host and target are the same system. Child process
4174 handling and core file support are two common `native' examples.
4176 GDB's use of /proc for controlling Unix child processes is now cleaner.
4177 It has been split out into a single module under the `target_ops' vector,
4178 plus two native-dependent functions for each system that uses /proc.
4180 * New hosts supported
4182 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4183 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4184 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4186 * New targets supported
4188 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4189 68030 and CPU32 m68030-*-*, m68332-*-*
4191 * New native hosts supported
4193 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4194 (386bsd is not well tested yet)
4195 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4197 * New file formats supported
4199 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4200 supports reading of `a.out.adobe' object files, which are an a.out
4201 format extended with minimal information about multiple sections.
4205 `show copying' is the same as the old `info copying'.
4206 `show warranty' is the same as `info warrantee'.
4207 These were renamed for consistency. The old commands continue to work.
4209 `info handle' is a new alias for `info signals'.
4211 You can now define pre-command hooks, which attach arbitrary command
4212 scripts to any command. The commands in the hook will be executed
4213 prior to the user's command. You can also create a hook which will be
4214 executed whenever the program stops. See gdb.texinfo.
4218 We now deal with Cfront style name mangling, and can even extract type
4219 info from mangled symbols. GDB can automatically figure out which
4220 symbol mangling style your C++ compiler uses.
4222 Calling of methods and virtual functions has been improved as well.
4226 The crash that occured when debugging Sun Ansi-C compiled binaries is
4227 fixed. This was due to mishandling of the extra N_SO stabs output
4230 We also finally got Ultrix 4.2 running in house, and fixed core file
4231 support, with help from a dozen people on the net.
4233 John M. Farrell discovered that the reason that single-stepping was so
4234 slow on all of the Mips based platforms (primarily SGI and DEC) was
4235 that we were trying to demangle and lookup a symbol used for internal
4236 purposes on every instruction that was being stepped through. Changing
4237 the name of that symbol so that it couldn't be mistaken for a C++
4238 mangled symbol sped things up a great deal.
4240 Rich Pixley sped up symbol lookups in general by getting much smarter
4241 about when C++ symbol mangling is necessary. This should make symbol
4242 completion (TAB on the command line) much faster. It's not as fast as
4243 we'd like, but it's significantly faster than gdb-4.6.
4247 A new user controllable variable 'call_scratch_address' can
4248 specify the location of a scratch area to be used when GDB
4249 calls a function in the target. This is necessary because the
4250 usual method of putting the scratch area on the stack does not work
4251 in systems that have separate instruction and data spaces.
4253 We integrated changes to support the 29k UDI (Universal Debugger
4254 Interface), but discovered at the last minute that we didn't have all
4255 of the appropriate copyright paperwork. We are working with AMD to
4256 resolve this, and hope to have it available soon.
4260 We have sped up the remote serial line protocol, especially for targets
4261 with lots of registers. It now supports a new `expedited status' ('T')
4262 message which can be used in place of the existing 'S' status message.
4263 This allows the remote stub to send only the registers that GDB
4264 needs to make a quick decision about single-stepping or conditional
4265 breakpoints, eliminating the need to fetch the entire register set for
4266 each instruction being stepped through.
4268 The GDB remote serial protocol now implements a write-through cache for
4269 registers, only re-reading the registers if the target has run.
4271 There is also a new remote serial stub for SPARC processors. You can
4272 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4273 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4274 processor with a serial port.
4278 Configure.in files have become much easier to read and modify. A new
4279 `table driven' format makes it more obvious what configurations are
4280 supported, and what files each one uses.
4284 There is a new opcodes library which will eventually contain all of the
4285 disassembly routines and opcode tables. At present, it only contains
4286 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4287 disassembler (binutils/objdump) to share these routines.
4289 The libiberty library is now copylefted under the GNU Library General
4290 Public License. This allows more liberal use, and was done so libg++
4291 can use it. This makes no difference to GDB, since the Library License
4292 grants all the rights from the General Public License.
4296 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4297 reference to the stabs symbol info used by the debugger. It is (as far
4298 as we know) the only published document on this fascinating topic. We
4299 encourage you to read it, compare it to the stabs information on your
4300 system, and send improvements on the document in general (to
4301 bug-gdb@prep.ai.mit.edu).
4303 And, of course, many bugs have been fixed.
4306 *** Changes in GDB-4.6:
4308 * Better support for C++ function names
4310 GDB now accepts as input the "demangled form" of C++ overloaded function
4311 names and member function names, and can do command completion on such names
4312 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4313 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4314 Make use of command completion, it is your friend.
4316 GDB also now accepts a variety of C++ mangled symbol formats. They are
4317 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4318 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4319 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4320 for the list of formats.
4322 * G++ symbol mangling problem
4324 Recent versions of gcc have a bug in how they emit debugging information for
4325 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4326 directory) can be applied to gcc to fix the problem. Alternatively, if you
4327 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4328 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4329 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4332 * New 'maintenance' command
4334 All of the commands related to hacking GDB internals have been moved out of
4335 the main command set, and now live behind the 'maintenance' command. This
4336 can also be abbreviated as 'mt'. The following changes were made:
4338 dump-me -> maintenance dump-me
4339 info all-breakpoints -> maintenance info breakpoints
4340 printmsyms -> maintenance print msyms
4341 printobjfiles -> maintenance print objfiles
4342 printpsyms -> maintenance print psymbols
4343 printsyms -> maintenance print symbols
4345 The following commands are new:
4347 maintenance demangle Call internal GDB demangler routine to
4348 demangle a C++ link name and prints the result.
4349 maintenance print type Print a type chain for a given symbol
4351 * Change to .gdbinit file processing
4353 We now read the $HOME/.gdbinit file before processing the argv arguments
4354 (e.g. reading symbol files or core files). This allows global parameters to
4355 be set, which will apply during the symbol reading. The ./.gdbinit is still
4356 read after argv processing.
4358 * New hosts supported
4360 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4362 GNU/Linux support i386-unknown-linux or linux
4364 We are also including code to support the HP/PA running BSD and HPUX. This
4365 is almost guaranteed not to work, as we didn't have time to test or build it
4366 for this release. We are including it so that the more adventurous (or
4367 masochistic) of you can play with it. We also had major problems with the
4368 fact that the compiler that we got from HP doesn't support the -g option.
4371 * New targets supported
4373 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4375 * More smarts about finding #include files
4377 GDB now remembers the compilation directory for all include files, and for
4378 all files from which C is generated (like yacc and lex sources). This
4379 greatly improves GDB's ability to find yacc/lex sources, and include files,
4380 especially if you are debugging your program from a directory different from
4381 the one that contains your sources.
4383 We also fixed a bug which caused difficulty with listing and setting
4384 breakpoints in include files which contain C code. (In the past, you had to
4385 try twice in order to list an include file that you hadn't looked at before.)
4387 * Interesting infernals change
4389 GDB now deals with arbitrary numbers of sections, where the symbols for each
4390 section must be relocated relative to that section's landing place in the
4391 target's address space. This work was needed to support ELF with embedded
4392 stabs used by Solaris-2.0.
4394 * Bug fixes (of course!)
4396 There have been loads of fixes for the following things:
4397 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4398 i960, stabs, DOS(GO32), procfs, etc...
4400 See the ChangeLog for details.
4402 *** Changes in GDB-4.5:
4404 * New machines supported (host and target)
4406 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4408 SGI Irix-4.x mips-sgi-irix4 or iris4
4410 * New malloc package
4412 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4413 Mmalloc is capable of handling mutiple heaps of memory. It is also
4414 capable of saving a heap to a file, and then mapping it back in later.
4415 This can be used to greatly speedup the startup of GDB by using a
4416 pre-parsed symbol table which lives in a mmalloc managed heap. For
4417 more details, please read mmalloc/mmalloc.texi.
4421 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4422 'help info proc' for details.
4424 * MIPS ecoff symbol table format
4426 The code that reads MIPS symbol table format is now supported on all hosts.
4427 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4430 * File name changes for MS-DOS
4432 Many files in the config directories have been renamed to make it easier to
4433 support GDB on MS-DOSe systems (which have very restrictive file name
4434 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4435 environment) is close to working but has some remaining problems. Note
4436 that debugging of DOS programs is not supported, due to limitations
4437 in the ``operating system'', but it can be used to host cross-debugging.
4439 * Cross byte order fixes
4441 Many fixes have been made to support cross debugging of Sparc and MIPS
4442 targets from hosts whose byte order differs.
4444 * New -mapped and -readnow options
4446 If memory-mapped files are available on your system through the 'mmap'
4447 system call, you can use the -mapped option on the `file' or
4448 `symbol-file' commands to cause GDB to write the symbols from your
4449 program into a reusable file. If the program you are debugging is
4450 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4451 Future GDB debugging sessions will notice the presence of this file,
4452 and will quickly map in symbol information from it, rather than reading
4453 the symbol table from the executable program. Using the '-mapped'
4454 option in a GDB `file' or `symbol-file' command has the same effect as
4455 starting GDB with the '-mapped' command-line option.
4457 You can cause GDB to read the entire symbol table immediately by using
4458 the '-readnow' option with any of the commands that load symbol table
4459 information (or on the GDB command line). This makes the command
4460 slower, but makes future operations faster.
4462 The -mapped and -readnow options are typically combined in order to
4463 build a `fred.syms' file that contains complete symbol information.
4464 A simple GDB invocation to do nothing but build a `.syms' file for future
4467 gdb -batch -nx -mapped -readnow programname
4469 The `.syms' file is specific to the host machine on which GDB is run.
4470 It holds an exact image of GDB's internal symbol table. It cannot be
4471 shared across multiple host platforms.
4473 * longjmp() handling
4475 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4476 siglongjmp() without losing control. This feature has not yet been ported to
4477 all systems. It currently works on many 386 platforms, all MIPS-based
4478 platforms (SGI, DECstation, etc), and Sun3/4.
4482 Preliminary work has been put in to support the new Solaris OS from Sun. At
4483 this time, it can control and debug processes, but it is not capable of
4488 As always, many many bug fixes. The major areas were with g++, and mipsread.
4489 People using the MIPS-based platforms should experience fewer mysterious
4490 crashes and trashed symbol tables.
4492 *** Changes in GDB-4.4:
4494 * New machines supported (host and target)
4496 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4498 BSD Reno on Vax vax-dec-bsd
4499 Ultrix on Vax vax-dec-ultrix
4501 * New machines supported (target)
4503 AMD 29000 embedded, using EBMON a29k-none-none
4507 GDB continues to improve its handling of C++. `References' work better.
4508 The demangler has also been improved, and now deals with symbols mangled as
4509 per the Annotated C++ Reference Guide.
4511 GDB also now handles `stabs' symbol information embedded in MIPS
4512 `ecoff' symbol tables. Since the ecoff format was not easily
4513 extensible to handle new languages such as C++, this appeared to be a
4514 good way to put C++ debugging info into MIPS binaries. This option
4515 will be supported in the GNU C compiler, version 2, when it is
4518 * New features for SVR4
4520 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4521 shared libraries. Debugging dynamically linked programs should present
4522 only minor differences from debugging statically linked programs.
4524 The `info proc' command will print out information about any process
4525 on an SVR4 system (including the one you are debugging). At the moment,
4526 it prints the address mappings of the process.
4528 If you bring up GDB on another SVR4 system, please send mail to
4529 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4531 * Better dynamic linking support in SunOS
4533 Reading symbols from shared libraries which contain debugging symbols
4534 now works properly. However, there remain issues such as automatic
4535 skipping of `transfer vector' code during function calls, which
4536 make it harder to debug code in a shared library, than to debug the
4537 same code linked statically.
4541 GDB is now using the latest `getopt' routines from the FSF. This
4542 version accepts the -- prefix for options with long names. GDB will
4543 continue to accept the old forms (-option and +option) as well.
4544 Various single letter abbreviations for options have been explicity
4545 added to the option table so that they won't get overshadowed in the
4546 future by other options that begin with the same letter.
4550 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4551 Many assorted bugs have been handled. Many more remain to be handled.
4552 See the various ChangeLog files (primarily in gdb and bfd) for details.
4555 *** Changes in GDB-4.3:
4557 * New machines supported (host and target)
4559 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4560 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4561 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4563 * Almost SCO Unix support
4565 We had hoped to support:
4566 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4567 (except for core file support), but we discovered very late in the release
4568 that it has problems with process groups that render gdb unusable. Sorry
4569 about that. I encourage people to fix it and post the fixes.
4571 * Preliminary ELF and DWARF support
4573 GDB can read ELF object files on System V Release 4, and can handle
4574 debugging records for C, in DWARF format, in ELF files. This support
4575 is preliminary. If you bring up GDB on another SVR4 system, please
4576 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4581 GDB now uses the latest `readline' library. One user-visible change
4582 is that two tabs will list possible command completions, which previously
4583 required typing M-? (meta-question mark, or ESC ?).
4587 The `stepi' bug that many of you noticed has been squashed.
4588 Many bugs in C++ have been handled. Many more remain to be handled.
4589 See the various ChangeLog files (primarily in gdb and bfd) for details.
4591 * State of the MIPS world (in case you wondered):
4593 GDB can understand the symbol tables emitted by the compilers
4594 supplied by most vendors of MIPS-based machines, including DEC. These
4595 symbol tables are in a format that essentially nobody else uses.
4597 Some versions of gcc come with an assembler post-processor called
4598 mips-tfile. This program is required if you want to do source-level
4599 debugging of gcc-compiled programs. I believe FSF does not ship
4600 mips-tfile with gcc version 1, but it will eventually come with gcc
4603 Debugging of g++ output remains a problem. g++ version 1.xx does not
4604 really support it at all. (If you're lucky, you should be able to get
4605 line numbers and stack traces to work, but no parameters or local
4606 variables.) With some work it should be possible to improve the
4609 When gcc version 2 is released, you will have somewhat better luck.
4610 However, even then you will get confusing results for inheritance and
4613 We will eventually provide full debugging of g++ output on
4614 DECstations. This will probably involve some kind of stabs-in-ecoff
4615 encapulation, but the details have not been worked out yet.
4618 *** Changes in GDB-4.2:
4620 * Improved configuration
4622 Only one copy of `configure' exists now, and it is not self-modifying.
4623 Porting BFD is simpler.
4627 The `step' and `next' commands now only stop at the first instruction
4628 of a source line. This prevents the multiple stops that used to occur
4629 in switch statements, for-loops, etc. `Step' continues to stop if a
4630 function that has debugging information is called within the line.
4634 Lots of small bugs fixed. More remain.
4636 * New host supported (not target)
4638 Intel 386 PC clone running Mach i386-none-mach
4641 *** Changes in GDB-4.1:
4643 * Multiple source language support
4645 GDB now has internal scaffolding to handle several source languages.
4646 It determines the type of each source file from its filename extension,
4647 and will switch expression parsing and number formatting to match the
4648 language of the function in the currently selected stack frame.
4649 You can also specifically set the language to be used, with
4650 `set language c' or `set language modula-2'.
4654 GDB now has preliminary support for the GNU Modula-2 compiler,
4655 currently under development at the State University of New York at
4656 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4657 continue through the fall of 1991 and into 1992.
4659 Other Modula-2 compilers are currently not supported, and attempting to
4660 debug programs compiled with them will likely result in an error as the
4661 symbol table is read. Feel free to work on it, though!
4663 There are hooks in GDB for strict type checking and range checking,
4664 in the `Modula-2 philosophy', but they do not currently work.
4668 GDB can now write to executable and core files (e.g. patch
4669 a variable's value). You must turn this switch on, specify
4670 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4671 by assigning a new value to a variable. Modifications take
4674 * Automatic SunOS shared library reading
4676 When you run your program, GDB automatically determines where its
4677 shared libraries (if any) have been loaded, and reads their symbols.
4678 The `share' command is no longer needed. This also works when
4679 examining core files.
4683 You can specify the number of lines that the `list' command shows.
4686 * New machines supported (host and target)
4688 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4689 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4690 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4692 * New hosts supported (not targets)
4694 IBM RT/PC: romp-ibm-aix or rtpc
4696 * New targets supported (not hosts)
4698 AMD 29000 embedded with COFF a29k-none-coff
4699 AMD 29000 embedded with a.out a29k-none-aout
4700 Ultracomputer remote kernel debug a29k-nyu-kern
4702 * New remote interfaces
4708 *** Changes in GDB-4.0:
4712 Wide output is wrapped at good places to make the output more readable.
4714 Gdb now supports cross-debugging from a host machine of one type to a
4715 target machine of another type. Communication with the target system
4716 is over serial lines. The ``target'' command handles connecting to the
4717 remote system; the ``load'' command will download a program into the
4718 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4719 also supports debugging of realtime processes running under VxWorks,
4720 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4721 stub on the target system.
4723 New CPUs supported include the AMD 29000 and Intel 960.
4725 GDB now reads object files and symbol tables via a ``binary file''
4726 library, which allows a single copy of GDB to debug programs of multiple
4727 object file types such as a.out and coff.
4729 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4730 refcard.dvi and refcard.ps are available to format it).
4733 * Control-Variable user interface simplified
4735 All variables that control the operation of the debugger can be set
4736 by the ``set'' command, and displayed by the ``show'' command.
4738 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4739 ``Show prompt'' produces the response:
4740 Gdb's prompt is new-gdb=>.
4742 What follows are the NEW set commands. The command ``help set'' will
4743 print a complete list of old and new set commands. ``help set FOO''
4744 will give a longer description of the variable FOO. ``show'' will show
4745 all of the variable descriptions and their current settings.
4747 confirm on/off: Enables warning questions for operations that are
4748 hard to recover from, e.g. rerunning the program while
4749 it is already running. Default is ON.
4751 editing on/off: Enables EMACS style command line editing
4752 of input. Previous lines can be recalled with
4753 control-P, the current line can be edited with control-B,
4754 you can search for commands with control-R, etc.
4757 history filename NAME: NAME is where the gdb command history
4758 will be stored. The default is .gdb_history,
4759 or the value of the environment variable
4762 history size N: The size, in commands, of the command history. The
4763 default is 256, or the value of the environment variable
4766 history save on/off: If this value is set to ON, the history file will
4767 be saved after exiting gdb. If set to OFF, the
4768 file will not be saved. The default is OFF.
4770 history expansion on/off: If this value is set to ON, then csh-like
4771 history expansion will be performed on
4772 command line input. The default is OFF.
4774 radix N: Sets the default radix for input and output. It can be set
4775 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4776 in the current radix, so "set radix 10" is always a no-op.
4778 height N: This integer value is the number of lines on a page. Default
4779 is 24, the current `stty rows'' setting, or the ``li#''
4780 setting from the termcap entry matching the environment
4783 width N: This integer value is the number of characters on a line.
4784 Default is 80, the current `stty cols'' setting, or the ``co#''
4785 setting from the termcap entry matching the environment
4788 Note: ``set screensize'' is obsolete. Use ``set height'' and
4789 ``set width'' instead.
4791 print address on/off: Print memory addresses in various command displays,
4792 such as stack traces and structure values. Gdb looks
4793 more ``symbolic'' if you turn this off; it looks more
4794 ``machine level'' with it on. Default is ON.
4796 print array on/off: Prettyprint arrays. New convenient format! Default
4799 print demangle on/off: Print C++ symbols in "source" form if on,
4802 print asm-demangle on/off: Same, for assembler level printouts
4805 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4808 * Support for Epoch Environment.
4810 The epoch environment is a version of Emacs v18 with windowing. One
4811 new command, ``inspect'', is identical to ``print'', except that if you
4812 are running in the epoch environment, the value is printed in its own
4816 * Support for Shared Libraries
4818 GDB can now debug programs and core files that use SunOS shared libraries.
4819 Symbols from a shared library cannot be referenced
4820 before the shared library has been linked with the program (this
4821 happens after you type ``run'' and before the function main() is entered).
4822 At any time after this linking (including when examining core files
4823 from dynamically linked programs), gdb reads the symbols from each
4824 shared library when you type the ``sharedlibrary'' command.
4825 It can be abbreviated ``share''.
4827 sharedlibrary REGEXP: Load shared object library symbols for files
4828 matching a unix regular expression. No argument
4829 indicates to load symbols for all shared libraries.
4831 info sharedlibrary: Status of loaded shared libraries.
4836 A watchpoint stops execution of a program whenever the value of an
4837 expression changes. Checking for this slows down execution
4838 tremendously whenever you are in the scope of the expression, but is
4839 quite useful for catching tough ``bit-spreader'' or pointer misuse
4840 problems. Some machines such as the 386 have hardware for doing this
4841 more quickly, and future versions of gdb will use this hardware.
4843 watch EXP: Set a watchpoint (breakpoint) for an expression.
4845 info watchpoints: Information about your watchpoints.
4847 delete N: Deletes watchpoint number N (same as breakpoints).
4848 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4849 enable N: Re-enables watchpoint number N (same as breakpoints).
4852 * C++ multiple inheritance
4854 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4857 * C++ exception handling
4859 Gdb now supports limited C++ exception handling. Besides the existing
4860 ability to breakpoint on an exception handler, gdb can breakpoint on
4861 the raising of an exception (before the stack is peeled back to the
4864 catch FOO: If there is a FOO exception handler in the dynamic scope,
4865 set a breakpoint to catch exceptions which may be raised there.
4866 Multiple exceptions (``catch foo bar baz'') may be caught.
4868 info catch: Lists all exceptions which may be caught in the
4869 current stack frame.
4872 * Minor command changes
4874 The command ``call func (arg, arg, ...)'' now acts like the print
4875 command, except it does not print or save a value if the function's result
4876 is void. This is similar to dbx usage.
4878 The ``up'' and ``down'' commands now always print the frame they end up
4879 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4880 frames without printing.
4882 * New directory command
4884 'dir' now adds directories to the FRONT of the source search path.
4885 The path starts off empty. Source files that contain debug information
4886 about the directory in which they were compiled can be found even
4887 with an empty path; Sun CC and GCC include this information. If GDB can't
4888 find your source file in the current directory, type "dir .".
4890 * Configuring GDB for compilation
4892 For normal use, type ``./configure host''. See README or gdb.texinfo
4895 GDB now handles cross debugging. If you are remotely debugging between
4896 two different machines, type ``./configure host -target=targ''.
4897 Host is the machine where GDB will run; targ is the machine
4898 where the program that you are debugging will run.