1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
6 * GDB now supports reversible debugging on ARM, it allows you to
7 debug basic ARM and THUMB instructions, and provides
10 * The option "symbol-reloading" has been deleted as it is no longer used.
14 ** GDB commands implemented in Python can now be put in command class
17 ** The "maint set python print-stack on|off" is now deleted.
19 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
20 apply "flag enum"-style pretty-printing to any enum.
22 ** gdb.lookup_symbol can now work when there is no current frame.
24 ** gdb.Symbol now has a 'line' attribute, holding the line number in
25 the source at which the symbol was defined.
27 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
28 method 'value'. The former indicates whether the symbol needs a
29 frame in order to compute its value, and the latter computes the
32 ** A new method 'referenced_value' on gdb.Value objects which can
33 dereference pointer as well as C++ reference values.
35 * GDBserver now supports stdio connections.
36 E.g. (gdb) target remote | ssh myhost gdbserver - hello
38 * The binary "gdbtui" can no longer be built or installed.
39 Use "gdb -tui" instead.
41 * GDB will now print "flag" enums specially. A flag enum is one where
42 all the enumerator values have no bits in common when pairwise
43 "and"ed. When printing a value whose type is a flag enum, GDB will
44 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
45 (gdb) print (enum E) 3
48 * The filename part of a linespec will now match trailing components
49 of a source file name. For example, "break gcc/expr.c:1000" will
50 now set a breakpoint in build/gcc/expr.c, but not
53 * The "info proc" and "generate-core-file" commands will now also
54 work on remote targets connected to GDBserver on Linux.
56 * The command "info catch" has been removed. It has been disabled
59 * The "catch exception" and "catch assert" commands now accept
60 a condition at the end of the command, much like the "break"
61 command does. For instance:
63 (gdb) catch exception Constraint_Error if Barrier = True
65 Previously, it was possible to add a condition to such catchpoints,
66 but it had to be done as a second step, after the catchpoint had been
67 created, using the "condition" command.
69 * The "info static-tracepoint-marker" command will now also work on
70 native Linux targets with in-process agent.
72 * GDB can now set breakpoints on inlined functions.
74 * The .gdb_index section has been updated to include symbols for
75 inlined functions. GDB will ignore older .gdb_index sections by
76 default, which could cause symbol files to be loaded more slowly
77 until their .gdb_index sections can be recreated. The new option
78 --use-deprecated-index-sections will cause GDB to use any older
79 .gdb_index sections it finds. This will restore performance, but
80 the ability to set breakpoints on inlined functions will be lost
81 in symbol files with older .gdb_index sections.
83 * Ada support for GDB/MI Variable Objects has been added.
87 ** "catch load" and "catch unload" can be used to stop when a shared
88 library is loaded or unloaded, respectively.
90 ** "enable count" can be used to auto-disable a breakpoint after
93 ** "info vtbl" can be used to show the virtual method tables for
98 Renesas RL78 rl78-*-elf
99 HP OpenVMS ia64 ia64-hp-openvms*
101 * GDBserver supports evaluation of breakpoint conditions. When
102 support is advertised by GDBserver, GDB may be told to send the
103 breakpoint conditions in bytecode form to GDBserver. GDBserver
104 will only report the breakpoint trigger to GDB when its condition
109 set breakpoint condition-evaluation
110 show breakpoint condition-evaluation
111 Control whether breakpoint conditions are evaluated by GDB ("host") or by
112 GDBserver ("target"). Default option "auto" chooses the most efficient
114 This option can improve debugger efficiency depending on the speed of the
119 z0/z1 conditional breakpoints extension
121 The z0/z1 breakpoint insertion packets have been extended to carry
122 a list of conditional expressions over to the remote stub depending on the
123 condition evaluation mode. The use of this extension can be controlled
124 via the "set remote conditional-breakpoints-packet" command.
128 Specify the signals which the remote stub may pass to the debugged
129 program without GDB involvement.
131 * New command line options
133 --init-command=FILE, -ix Like --command, -x but execute it
134 before loading inferior.
135 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
136 execute it before loading inferior.
138 *** Changes in GDB 7.4
140 * GDB now handles ambiguous linespecs more consistently; the existing
141 FILE:LINE support has been expanded to other types of linespecs. A
142 breakpoint will now be set on all matching locations in all
143 inferiors, and locations will be added or removed according to
146 * GDB now allows you to skip uninteresting functions and files when
147 stepping with the "skip function" and "skip file" commands.
149 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
150 and "show remote hardware-watchpoint-length-limit". These allows to
151 set or show the maximum length limit (in bytes) of a remote
152 target hardware watchpoint.
154 This allows e.g. to use "unlimited" hardware watchpoints with the
155 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
156 watchpoints are slower than real hardware watchpoints but are
157 significantly faster than gdb software watchpoints.
161 ** The register_pretty_printer function in module gdb.printing now takes
162 an optional `replace' argument. If True, the new printer replaces any
165 ** The "maint set python print-stack on|off" command has been
166 deprecated and will be deleted in GDB 7.5.
167 A new command: "set python print-stack none|full|message" has
168 replaced it. Additionally, the default for "print-stack" is
169 now "message", which just prints the error message without
172 ** A prompt substitution hook (prompt_hook) is now available to the
175 ** A new Python module, gdb.prompt has been added to the GDB Python
176 modules library. This module provides functionality for
177 escape sequences in prompts (used by set/show
178 extended-prompt). These escape sequences are replaced by their
181 ** Python commands and convenience-functions located in
182 'data-directory'/python/gdb/command and
183 'data-directory'/python/gdb/function are now automatically loaded
186 ** Blocks now provide four new attributes. global_block and
187 static_block will return the global and static blocks
188 respectively. is_static and is_global are boolean attributes
189 that indicate if the block is one of those two types.
191 ** Symbols now provide the "type" attribute, the type of the symbol.
193 ** The "gdb.breakpoint" function has been deprecated in favor of
196 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
197 of a function. This class is based on the "finish" command
198 available in the CLI.
200 ** Type objects for struct and union types now allow access to
201 the fields using standard Python dictionary (mapping) methods.
202 For example, "some_type['myfield']" now works, as does
205 ** A new event "gdb.new_objfile" has been added, triggered by loading a
208 ** A new function, "deep_items" has been added to the gdb.types
209 module in the GDB Python modules library. This function returns
210 an iterator over the fields of a struct or union type. Unlike
211 the standard Python "iteritems" method, it will recursively traverse
212 any anonymous fields.
216 ** "*stopped" events can report several new "reason"s, such as
219 ** Breakpoint changes are now notified using new async records, like
220 "=breakpoint-modified".
222 ** New command -ada-task-info.
224 * libthread-db-search-path now supports two special values: $sdir and $pdir.
225 $sdir specifies the default system locations of shared libraries.
226 $pdir specifies the directory where the libpthread used by the application
229 GDB no longer looks in $sdir and $pdir after it has searched the directories
230 mentioned in libthread-db-search-path. If you want to search those
231 directories, they must be specified in libthread-db-search-path.
232 The default value of libthread-db-search-path on GNU/Linux and Solaris
233 systems is now "$sdir:$pdir".
235 $pdir is not supported by gdbserver, it is currently ignored.
236 $sdir is supported by gdbserver.
238 * New configure option --with-iconv-bin.
239 When using the internationalization support like the one in the GNU C
240 library, GDB will invoke the "iconv" program to get a list of supported
241 character sets. If this program lives in a non-standard location, one can
242 use this option to specify where to find it.
244 * When natively debugging programs on PowerPC BookE processors running
245 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
246 watchpoints, which specify a mask in addition to an address to watch.
247 The mask specifies that some bits of an address (the bits which are
248 reset in the mask) should be ignored when matching the address accessed
249 by the inferior against the watchpoint address. See the "PowerPC Embedded"
250 section in the user manual for more details.
252 * The new option --once causes GDBserver to stop listening for connections once
253 the first connection is made. The listening port used by GDBserver will
254 become available after that.
256 * New commands "info macros" and "alias" have been added.
258 * New function parameters suffix @entry specifies value of function parameter
259 at the time the function got called. Entry values are available only since
265 "!" is now an alias of the "shell" command.
266 Note that no space is needed between "!" and SHELL COMMAND.
270 watch EXPRESSION mask MASK_VALUE
271 The watch command now supports the mask argument which allows creation
272 of masked watchpoints, if the current architecture supports this feature.
274 info auto-load-scripts [REGEXP]
275 This command was formerly named "maintenance print section-scripts".
276 It is now generally useful and is no longer a maintenance-only command.
278 info macro [-all] [--] MACRO
279 The info macro command has new options `-all' and `--'. The first for
280 printing all definitions of a macro. The second for explicitly specifying
281 the end of arguments and the beginning of the macro name in case the macro
282 name starts with a hyphen.
284 collect[/s] EXPRESSIONS
285 The tracepoint collect command now takes an optional modifier "/s"
286 that directs it to dereference pointer-to-character types and
287 collect the bytes of memory up to a zero byte. The behavior is
288 similar to what you see when you use the regular print command on a
289 string. An optional integer following the "/s" sets a bound on the
290 number of bytes that will be collected.
293 The trace start command now interprets any supplied arguments as a
294 note to be recorded with the trace run, with an effect similar to
295 setting the variable trace-notes.
298 The trace stop command now interprets any arguments as a note to be
299 mentioned along with the tstatus report that the trace was stopped
300 with a command. The effect is similar to setting the variable
303 * Tracepoints can now be enabled and disabled at any time after a trace
304 experiment has been started using the standard "enable" and "disable"
305 commands. It is now possible to start a trace experiment with no enabled
306 tracepoints; GDB will display a warning, but will allow the experiment to
307 begin, assuming that tracepoints will be enabled as needed while the trace
310 * Fast tracepoints on 32-bit x86-architectures can now be placed at
311 locations with 4-byte instructions, when they were previously
312 limited to locations with instructions of 5 bytes or longer.
318 Set the GDB prompt, and allow escape sequences to be inserted to
319 display miscellaneous information (see 'help set extended-prompt'
320 for the list of sequences). This prompt (and any information
321 accessed through the escape sequences) is updated every time the
324 set print entry-values (both|compact|default|if-needed|no|only|preferred)
325 show print entry-values
326 Set printing of frame argument values at function entry. In some cases
327 GDB can determine the value of function argument which was passed by the
328 function caller, even if the value was modified inside the called function.
330 set debug entry-values
331 show debug entry-values
332 Control display of debugging info for determining frame argument values at
333 function entry and virtual tail call frames.
335 set basenames-may-differ
336 show basenames-may-differ
337 Set whether a source file may have multiple base names.
338 (A "base name" is the name of a file with the directory part removed.
339 Example: The base name of "/home/user/hello.c" is "hello.c".)
340 If set, GDB will canonicalize file names (e.g., expand symlinks)
341 before comparing them. Canonicalization is an expensive operation,
342 but it allows the same file be known by more than one base name.
343 If not set (the default), all source files are assumed to have just
344 one base name, and gdb will do file name comparisons more efficiently.
350 Set a user name and notes for the current and any future trace runs.
351 This is useful for long-running and/or disconnected traces, to
352 inform others (or yourself) as to who is running the trace, supply
353 contact information, or otherwise explain what is going on.
356 show trace-stop-notes
357 Set a note attached to the trace run, that is displayed when the
358 trace has been stopped by a tstop command. This is useful for
359 instance as an explanation, if you are stopping a trace run that was
360 started by someone else.
366 Dynamically enable a tracepoint in a started trace experiment.
370 Dynamically disable a tracepoint in a started trace experiment.
374 Set the user and notes of the trace run.
378 Query the current status of a tracepoint.
382 Query the minimum length of instruction at which a fast tracepoint may
385 * Dcache size (number of lines) and line-size are now runtime-configurable
386 via "set dcache line" and "set dcache line-size" commands.
390 Texas Instruments TMS320C6x tic6x-*-*
394 Renesas RL78 rl78-*-elf
396 *** Changes in GDB 7.3.1
398 * The build failure for NetBSD and OpenBSD targets have now been fixed.
400 *** Changes in GDB 7.3
402 * GDB has a new command: "thread find [REGEXP]".
403 It finds the thread id whose name, target id, or thread extra info
404 matches the given regular expression.
406 * The "catch syscall" command now works on mips*-linux* targets.
408 * The -data-disassemble MI command now supports modes 2 and 3 for
409 dumping the instruction opcodes.
411 * New command line options
413 -data-directory DIR Specify DIR as the "data-directory".
414 This is mostly for testing purposes.
416 * The "maint set python auto-load on|off" command has been renamed to
417 "set auto-load-scripts on|off".
419 * GDB has a new command: "set directories".
420 It is like the "dir" command except that it replaces the
421 source path list instead of augmenting it.
423 * GDB now understands thread names.
425 On GNU/Linux, "info threads" will display the thread name as set by
426 prctl or pthread_setname_np.
428 There is also a new command, "thread name", which can be used to
429 assign a name internally for GDB to display.
432 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
433 has been integrated into GDB.
437 ** The function gdb.Write now accepts an optional keyword 'stream'.
438 This keyword, when provided, will direct the output to either
439 stdout, stderr, or GDB's logging output.
441 ** Parameters can now be be sub-classed in Python, and in particular
442 you may implement the get_set_doc and get_show_doc functions.
443 This improves how Parameter set/show documentation is processed
444 and allows for more dynamic content.
446 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
447 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
448 have an is_valid method.
450 ** Breakpoints can now be sub-classed in Python, and in particular
451 you may implement a 'stop' function that is executed each time
452 the inferior reaches that breakpoint.
454 ** New function gdb.lookup_global_symbol looks up a global symbol.
456 ** GDB values in Python are now callable if the value represents a
457 function. For example, if 'some_value' represents a function that
458 takes two integer parameters and returns a value, you can call
459 that function like so:
461 result = some_value (10,20)
463 ** Module gdb.types has been added.
464 It contains a collection of utilities for working with gdb.Types objects:
465 get_basic_type, has_field, make_enum_dict.
467 ** Module gdb.printing has been added.
468 It contains utilities for writing and registering pretty-printers.
469 New classes: PrettyPrinter, SubPrettyPrinter,
470 RegexpCollectionPrettyPrinter.
471 New function: register_pretty_printer.
473 ** New commands "info pretty-printers", "enable pretty-printer" and
474 "disable pretty-printer" have been added.
476 ** gdb.parameter("directories") is now available.
478 ** New function gdb.newest_frame returns the newest frame in the
481 ** The gdb.InferiorThread class has a new "name" attribute. This
482 holds the thread's name.
484 ** Python Support for Inferior events.
485 Python scripts can add observers to be notified of events
486 occurring in the process being debugged.
487 The following events are currently supported:
488 - gdb.events.cont Continue event.
489 - gdb.events.exited Inferior exited event.
490 - gdb.events.stop Signal received, and Breakpoint hit events.
494 ** GDB now puts template parameters in scope when debugging in an
495 instantiation. For example, if you have:
497 template<int X> int func (void) { return X; }
499 then if you step into func<5>, "print X" will show "5". This
500 feature requires proper debuginfo support from the compiler; it
501 was added to GCC 4.5.
503 ** The motion commands "next", "finish", "until", and "advance" now
504 work better when exceptions are thrown. In particular, GDB will
505 no longer lose control of the inferior; instead, the GDB will
506 stop the inferior at the point at which the exception is caught.
507 This functionality requires a change in the exception handling
508 code that was introduced in GCC 4.5.
510 * GDB now follows GCC's rules on accessing volatile objects when
511 reading or writing target state during expression evaluation.
512 One notable difference to prior behavior is that "print x = 0"
513 no longer generates a read of x; the value of the assignment is
514 now always taken directly from the value being assigned.
516 * GDB now has some support for using labels in the program's source in
517 linespecs. For instance, you can use "advance label" to continue
518 execution to a label.
520 * GDB now has support for reading and writing a new .gdb_index
521 section. This section holds a fast index of DWARF debugging
522 information and can be used to greatly speed up GDB startup and
523 operation. See the documentation for `save gdb-index' for details.
525 * The "watch" command now accepts an optional "-location" argument.
526 When used, this causes GDB to watch the memory referred to by the
527 expression. Such a watchpoint is never deleted due to it going out
530 * GDB now supports thread debugging of core dumps on GNU/Linux.
532 GDB now activates thread debugging using the libthread_db library
533 when debugging GNU/Linux core dumps, similarly to when debugging
534 live processes. As a result, when debugging a core dump file, GDB
535 is now able to display pthread_t ids of threads. For example, "info
536 threads" shows the same output as when debugging the process when it
537 was live. In earlier releases, you'd see something like this:
540 * 1 LWP 6780 main () at main.c:10
542 While now you see this:
545 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
547 It is also now possible to inspect TLS variables when debugging core
550 When debugging a core dump generated on a machine other than the one
551 used to run GDB, you may need to point GDB at the correct
552 libthread_db library with the "set libthread-db-search-path"
553 command. See the user manual for more details on this command.
555 * When natively debugging programs on PowerPC BookE processors running
556 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
557 which stop execution of the inferior whenever it executes an instruction
558 at any address within the specified range. See the "PowerPC Embedded"
559 section in the user manual for more details.
561 * New features in the GDB remote stub, GDBserver
563 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
564 and i686 LynxOS (version 5.x).
566 ** GDBserver is now supported on Blackfin Linux.
568 * New native configurations
570 ia64 HP-UX ia64-*-hpux*
574 Analog Devices, Inc. Blackfin Processor bfin-*
576 * Ada task switching is now supported on sparc-elf targets when
577 debugging a program using the Ravenscar Profile. For more information,
578 see the "Tasking Support when using the Ravenscar Profile" section
579 in the GDB user manual.
581 * Guile support was removed.
583 * New features in the GNU simulator
585 ** The --map-info flag lists all known core mappings.
587 ** CFI flashes may be simulated via the "cfi" device.
589 *** Changes in GDB 7.2
591 * Shared library support for remote targets by default
593 When GDB is configured for a generic, non-OS specific target, like
594 for example, --target=arm-eabi or one of the many *-*-elf targets,
595 GDB now queries remote stubs for loaded shared libraries using the
596 `qXfer:libraries:read' packet. Previously, shared library support
597 was always disabled for such configurations.
601 ** Argument Dependent Lookup (ADL)
603 In C++ ADL lookup directs function search to the namespaces of its
604 arguments even if the namespace has not been imported.
614 Here the compiler will search for `foo' in the namespace of 'b'
615 and find A::foo. GDB now supports this. This construct is commonly
616 used in the Standard Template Library for operators.
618 ** Improved User Defined Operator Support
620 In addition to member operators, GDB now supports lookup of operators
621 defined in a namespace and imported with a `using' directive, operators
622 defined in the global scope, operators imported implicitly from an
623 anonymous namespace, and the ADL operators mentioned in the previous
625 GDB now also supports proper overload resolution for all the previously
626 mentioned flavors of operators.
628 ** static const class members
630 Printing of static const class members that are initialized in the
631 class definition has been fixed.
633 * Windows Thread Information Block access.
635 On Windows targets, GDB now supports displaying the Windows Thread
636 Information Block (TIB) structure. This structure is visible either
637 by using the new command `info w32 thread-information-block' or, by
638 dereferencing the new convenience variable named `$_tlb', a
639 thread-specific pointer to the TIB. This feature is also supported
640 when remote debugging using GDBserver.
644 Static tracepoints are calls in the user program into a tracing
645 library. One such library is a port of the LTTng kernel tracer to
646 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
647 When debugging with GDBserver, GDB now supports combining the GDB
648 tracepoint machinery with such libraries. For example: the user can
649 use GDB to probe a static tracepoint marker (a call from the user
650 program into the tracing library) with the new "strace" command (see
651 "New commands" below). This creates a "static tracepoint" in the
652 breakpoint list, that can be manipulated with the same feature set
653 as fast and regular tracepoints. E.g., collect registers, local and
654 global variables, collect trace state variables, and define
655 tracepoint conditions. In addition, the user can collect extra
656 static tracepoint marker specific data, by collecting the new
657 $_sdata internal variable. When analyzing the trace buffer, you can
658 inspect $_sdata like any other variable available to GDB. For more
659 information, see the "Tracepoints" chapter in GDB user manual. New
660 remote packets have been defined to support static tracepoints, see
661 the "New remote packets" section below.
663 * Better reconstruction of tracepoints after disconnected tracing
665 GDB will attempt to download the original source form of tracepoint
666 definitions when starting a trace run, and then will upload these
667 upon reconnection to the target, resulting in a more accurate
668 reconstruction of the tracepoints that are in use on the target.
672 You can now exercise direct control over the ways that GDB can
673 affect your program. For instance, you can disallow the setting of
674 breakpoints, so that the program can run continuously (assuming
675 non-stop mode). In addition, the "observer" variable is available
676 to switch all of the different controls; in observer mode, GDB
677 cannot affect the target's behavior at all, which is useful for
678 tasks like diagnosing live systems in the field.
680 * The new convenience variable $_thread holds the number of the
687 Return the address of the Windows Thread Information Block of a given thread.
691 In response to several of the tracepoint packets, the target may now
692 also respond with a number of intermediate `qRelocInsn' request
693 packets before the final result packet, to have GDB handle
694 relocating an instruction to execute at a different address. This
695 is particularly useful for stubs that support fast tracepoints. GDB
696 reports support for this feature in the qSupported packet.
700 List static tracepoint markers in the target program.
704 List static tracepoint markers at a given address in the target
707 qXfer:statictrace:read
709 Read the static trace data collected (by a `collect $_sdata'
710 tracepoint action). The remote stub reports support for this packet
711 to gdb's qSupported query.
715 Send the current settings of GDB's permission flags.
719 Send part of the source (textual) form of a tracepoint definition,
720 which includes location, conditional, and action list.
722 * The source command now accepts a -s option to force searching for the
723 script in the source search path even if the script name specifies
726 * New features in the GDB remote stub, GDBserver
728 - GDBserver now support tracepoints (including fast tracepoints, and
729 static tracepoints). The feature is currently supported by the
730 i386-linux and amd64-linux builds. See the "Tracepoints support
731 in gdbserver" section in the manual for more information.
733 GDBserver JIT compiles the tracepoint's conditional agent
734 expression bytecode into native code whenever possible for low
735 overhead dynamic tracepoints conditionals. For such tracepoints,
736 an expression that examines program state is evaluated when the
737 tracepoint is reached, in order to determine whether to capture
738 trace data. If the condition is simple and false, processing the
739 tracepoint finishes very quickly and no data is gathered.
741 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
742 for static tracepoints support.
744 - GDBserver now supports x86_64 Windows 64-bit debugging.
746 * GDB now sends xmlRegisters= in qSupported packet to indicate that
747 it understands register description.
749 * The --batch flag now disables pagination and queries.
751 * X86 general purpose registers
753 GDB now supports reading/writing byte, word and double-word x86
754 general purpose registers directly. This means you can use, say,
755 $ah or $ax to refer, respectively, to the byte register AH and
756 16-bit word register AX that are actually portions of the 32-bit
757 register EAX or 64-bit register RAX.
759 * The `commands' command now accepts a range of breakpoints to modify.
760 A plain `commands' following a command that creates multiple
761 breakpoints affects all the breakpoints set by that command. This
762 applies to breakpoints set by `rbreak', and also applies when a
763 single `break' command creates multiple breakpoints (e.g.,
764 breakpoints on overloaded c++ functions).
766 * The `rbreak' command now accepts a filename specification as part of
767 its argument, limiting the functions selected by the regex to those
768 in the specified file.
770 * Support for remote debugging Windows and SymbianOS shared libraries
771 from Unix hosts has been improved. Non Windows GDB builds now can
772 understand target reported file names that follow MS-DOS based file
773 system semantics, such as file names that include drive letters and
774 use the backslash character as directory separator. This makes it
775 possible to transparently use the "set sysroot" and "set
776 solib-search-path" on Unix hosts to point as host copies of the
777 target's shared libraries. See the new command "set
778 target-file-system-kind" described below, and the "Commands to
779 specify files" section in the user manual for more information.
783 eval template, expressions...
784 Convert the values of one or more expressions under the control
785 of the string template to a command line, and call it.
787 set target-file-system-kind unix|dos-based|auto
788 show target-file-system-kind
789 Set or show the assumed file system kind for target reported file
792 save breakpoints <filename>
793 Save all current breakpoint definitions to a file suitable for use
794 in a later debugging session. To read the saved breakpoint
795 definitions, use the `source' command.
797 `save tracepoints' is a new alias for `save-tracepoints'. The latter
800 info static-tracepoint-markers
801 Display information about static tracepoint markers in the target.
803 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
804 Define a static tracepoint by probing a marker at the given
805 function, line, address, or marker ID.
809 Enable and disable observer mode.
811 set may-write-registers on|off
812 set may-write-memory on|off
813 set may-insert-breakpoints on|off
814 set may-insert-tracepoints on|off
815 set may-insert-fast-tracepoints on|off
816 set may-interrupt on|off
817 Set individual permissions for GDB effects on the target. Note that
818 some of these settings can have undesirable or surprising
819 consequences, particularly when changed in the middle of a session.
820 For instance, disabling the writing of memory can prevent
821 breakpoints from being inserted, cause single-stepping to fail, or
822 even crash your program, if you disable after breakpoints have been
823 inserted. However, GDB should not crash.
825 set record memory-query on|off
826 show record memory-query
827 Control whether to stop the inferior if memory changes caused
828 by an instruction cannot be recorded.
833 The disassemble command now supports "start,+length" form of two arguments.
837 ** GDB now provides a new directory location, called the python directory,
838 where Python scripts written for GDB can be installed. The location
839 of that directory is <data-directory>/python, where <data-directory>
840 is the GDB data directory. For more details, see section `Scripting
841 GDB using Python' in the manual.
843 ** The GDB Python API now has access to breakpoints, symbols, symbol
844 tables, program spaces, inferiors, threads and frame's code blocks.
845 Additionally, GDB Parameters can now be created from the API, and
846 manipulated via set/show in the CLI.
848 ** New functions gdb.target_charset, gdb.target_wide_charset,
849 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
851 ** New exception gdb.GdbError.
853 ** Pretty-printers are now also looked up in the current program space.
855 ** Pretty-printers can now be individually enabled and disabled.
857 ** GDB now looks for names of Python scripts to auto-load in a
858 special section named `.debug_gdb_scripts', in addition to looking
859 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
861 * Tracepoint actions were unified with breakpoint commands. In particular,
862 there are no longer differences in "info break" output for breakpoints and
863 tracepoints and the "commands" command can be used for both tracepoints and
868 ARM Symbian arm*-*-symbianelf*
870 * D language support.
871 GDB now supports debugging programs written in the D programming
874 * GDB now supports the extended ptrace interface for PowerPC which is
875 available since Linux kernel version 2.6.34. This automatically enables
876 any hardware breakpoints and additional hardware watchpoints available in
877 the processor. The old ptrace interface exposes just one hardware
878 watchpoint and no hardware breakpoints.
880 * GDB is now able to use the Data Value Compare (DVC) register available on
881 embedded PowerPC processors to implement in hardware simple watchpoint
882 conditions of the form:
884 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
886 This works in native GDB running on Linux kernels with the extended ptrace
887 interface mentioned above.
889 *** Changes in GDB 7.1
895 GDB now supports importing of namespaces in C++. This enables the
896 user to inspect variables from imported namespaces. Support for
897 namepace aliasing has also been added. So, if a namespace is
898 aliased in the current scope (e.g. namepace C=A; ) the user can
899 print variables using the alias (e.g. (gdb) print C::x).
903 All known bugs relating to the printing of virtual base class were
904 fixed. It is now possible to call overloaded static methods using a
909 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
910 and reinterpret_cast<> are now handled by the C++ expression parser.
914 Xilinx MicroBlaze microblaze-*-*
919 Xilinx MicroBlaze microblaze
922 * Multi-program debugging.
924 GDB now has support for multi-program (a.k.a. multi-executable or
925 multi-exec) debugging. This allows for debugging multiple inferiors
926 simultaneously each running a different program under the same GDB
927 session. See "Debugging Multiple Inferiors and Programs" in the
928 manual for more information. This implied some user visible changes
929 in the multi-inferior support. For example, "info inferiors" now
930 lists inferiors that are not running yet or that have exited
931 already. See also "New commands" and "New options" below.
933 * New tracing features
935 GDB's tracepoint facility now includes several new features:
937 ** Trace state variables
939 GDB tracepoints now include support for trace state variables, which
940 are variables managed by the target agent during a tracing
941 experiment. They are useful for tracepoints that trigger each
942 other, so for instance one tracepoint can count hits in a variable,
943 and then a second tracepoint has a condition that is true when the
944 count reaches a particular value. Trace state variables share the
945 $-syntax of GDB convenience variables, and can appear in both
946 tracepoint actions and condition expressions. Use the "tvariable"
947 command to create, and "info tvariables" to view; see "Trace State
948 Variables" in the manual for more detail.
952 GDB now includes an option for defining fast tracepoints, which
953 targets may implement more efficiently, such as by installing a jump
954 into the target agent rather than a trap instruction. The resulting
955 speedup can be by two orders of magnitude or more, although the
956 tradeoff is that some program locations on some target architectures
957 might not allow fast tracepoint installation, for instance if the
958 instruction to be replaced is shorter than the jump. To request a
959 fast tracepoint, use the "ftrace" command, with syntax identical to
960 the regular trace command.
962 ** Disconnected tracing
964 It is now possible to detach GDB from the target while it is running
965 a trace experiment, then reconnect later to see how the experiment
966 is going. In addition, a new variable disconnected-tracing lets you
967 tell the target agent whether to continue running a trace if the
968 connection is lost unexpectedly.
972 GDB now has the ability to save the trace buffer into a file, and
973 then use that file as a target, similarly to you can do with
974 corefiles. You can select trace frames, print data that was
975 collected in them, and use tstatus to display the state of the
976 tracing run at the moment that it was saved. To create a trace
977 file, use "tsave <filename>", and to use it, do "target tfile
980 ** Circular trace buffer
982 You can ask the target agent to handle the trace buffer as a
983 circular buffer, discarding the oldest trace frames to make room for
984 newer ones, by setting circular-trace-buffer to on. This feature may
985 not be available for all target agents.
990 The disassemble command, when invoked with two arguments, now requires
991 the arguments to be comma-separated.
994 The info variables command now displays variable definitions. Files
995 which only declare a variable are not shown.
998 The source command is now capable of sourcing Python scripts.
999 This feature is dependent on the debugger being build with Python
1002 Related to this enhancement is also the introduction of a new command
1003 "set script-extension" (see below).
1005 * New commands (for set/show, see "New options" below)
1007 record save [<FILENAME>]
1008 Save a file (in core file format) containing the process record
1009 execution log for replay debugging at a later time.
1011 record restore <FILENAME>
1012 Restore the process record execution log that was saved at an
1013 earlier time, for replay debugging.
1015 add-inferior [-copies <N>] [-exec <FILENAME>]
1018 clone-inferior [-copies <N>] [ID]
1019 Make a new inferior ready to execute the same program another
1020 inferior has loaded.
1025 maint info program-spaces
1026 List the program spaces loaded into GDB.
1028 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1029 show remote interrupt-sequence
1030 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1031 as the sequence to the remote target in order to interrupt the execution.
1032 Ctrl-C is a default. Some system prefers BREAK which is high level of
1033 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1034 Magic SysRq g. It is BREAK signal and character 'g'.
1036 set remote interrupt-on-connect [on | off]
1037 show remote interrupt-on-connect
1038 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1039 remote target when gdb connects to it. This is needed when you debug
1042 set remotebreak [on | off]
1044 Deprecated. Use "set/show remote interrupt-sequence" instead.
1046 tvariable $NAME [ = EXP ]
1047 Create or modify a trace state variable.
1050 List trace state variables and their values.
1052 delete tvariable $NAME ...
1053 Delete one or more trace state variables.
1056 Evaluate the given expressions without collecting anything into the
1057 trace buffer. (Valid in tracepoint actions only.)
1059 ftrace FN / FILE:LINE / *ADDR
1060 Define a fast tracepoint at the given function, line, or address.
1062 * New expression syntax
1064 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1065 GDB now parses 0b101010 identically with 42.
1069 set follow-exec-mode new|same
1070 show follow-exec-mode
1071 Control whether GDB reuses the same inferior across an exec call or
1072 creates a new one. This is useful to be able to restart the old
1073 executable after the inferior having done an exec call.
1075 set default-collect EXPR, ...
1076 show default-collect
1077 Define a list of expressions to be collected at each tracepoint.
1078 This is a useful way to ensure essential items are not overlooked,
1079 such as registers or a critical global variable.
1081 set disconnected-tracing
1082 show disconnected-tracing
1083 If set to 1, the target is instructed to continue tracing if it
1084 loses its connection to GDB. If 0, the target is to stop tracing
1087 set circular-trace-buffer
1088 show circular-trace-buffer
1089 If set to on, the target is instructed to use a circular trace buffer
1090 and discard the oldest trace frames instead of stopping the trace due
1091 to a full trace buffer. If set to off, the trace stops when the buffer
1092 fills up. Some targets may not support this.
1094 set script-extension off|soft|strict
1095 show script-extension
1096 If set to "off", the debugger does not perform any script language
1097 recognition, and all sourced files are assumed to be GDB scripts.
1098 If set to "soft" (the default), files are sourced according to
1099 filename extension, falling back to GDB scripts if the first
1101 If set to "strict", files are sourced according to filename extension.
1103 set ada trust-PAD-over-XVS on|off
1104 show ada trust-PAD-over-XVS
1105 If off, activate a workaround against a bug in the debugging information
1106 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1107 the GCC sources for more information about the GNAT encoding and
1108 PAD types in particular). It is always safe to set this option to
1109 off, but this introduces a slight performance penalty. The default
1112 * Python API Improvements
1114 ** GDB provides the new class gdb.LazyString. This is useful in
1115 some pretty-printing cases. The new method gdb.Value.lazy_string
1116 provides a simple way to create objects of this type.
1118 ** The fields returned by gdb.Type.fields now have an
1119 `is_base_class' attribute.
1121 ** The new method gdb.Type.range returns the range of an array type.
1123 ** The new method gdb.parse_and_eval can be used to parse and
1124 evaluate an expression.
1126 * New remote packets
1129 Define a trace state variable.
1132 Get the current value of a trace state variable.
1135 Set desired tracing behavior upon disconnection.
1138 Set the trace buffer to be linear or circular.
1141 Get data about the tracepoints currently in use.
1145 Process record now works correctly with hardware watchpoints.
1147 Multiple bug fixes have been made to the mips-irix port, making it
1148 much more reliable. In particular:
1149 - Debugging threaded applications is now possible again. Previously,
1150 GDB would hang while starting the program, or while waiting for
1151 the program to stop at a breakpoint.
1152 - Attaching to a running process no longer hangs.
1153 - An error occurring while loading a core file has been fixed.
1154 - Changing the value of the PC register now works again. This fixes
1155 problems observed when using the "jump" command, or when calling
1156 a function from GDB, or even when assigning a new value to $pc.
1157 - With the "finish" and "return" commands, the return value for functions
1158 returning a small array is now correctly printed.
1159 - It is now possible to break on shared library code which gets executed
1160 during a shared library init phase (code executed while executing
1161 their .init section). Previously, the breakpoint would have no effect.
1162 - GDB is now able to backtrace through the signal handler for
1163 non-threaded programs.
1165 PIE (Position Independent Executable) programs debugging is now supported.
1166 This includes debugging execution of PIC (Position Independent Code) shared
1167 libraries although for that, it should be possible to run such libraries as an
1170 *** Changes in GDB 7.0
1172 * GDB now has an interface for JIT compilation. Applications that
1173 dynamically generate code can create symbol files in memory and register
1174 them with GDB. For users, the feature should work transparently, and
1175 for JIT developers, the interface is documented in the GDB manual in the
1176 "JIT Compilation Interface" chapter.
1178 * Tracepoints may now be conditional. The syntax is as for
1179 breakpoints; either an "if" clause appended to the "trace" command,
1180 or the "condition" command is available. GDB sends the condition to
1181 the target for evaluation using the same bytecode format as is used
1182 for tracepoint actions.
1184 * The disassemble command now supports: an optional /r modifier, print the
1185 raw instructions in hex as well as in symbolic form, and an optional /m
1186 modifier to print mixed source+assembly.
1188 * Process record and replay
1190 In a architecture environment that supports ``process record and
1191 replay'', ``process record and replay'' target can record a log of
1192 the process execution, and replay it with both forward and reverse
1195 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1196 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1197 set execution-direction {forward|reverse}, for targets that support
1200 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1201 feature is available with a native GDB running on kernel version
1204 * GDB now has support for multi-byte and wide character sets on the
1205 target. Strings whose character type is wchar_t, char16_t, or
1206 char32_t are now correctly printed. GDB supports wide- and unicode-
1207 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1208 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1209 `printf'. This feature requires iconv to work properly; if your
1210 system does not have a working iconv, GDB can use GNU libiconv. See
1211 the installation instructions for more information.
1213 * GDB now supports automatic retrieval of shared library files from
1214 remote targets. To use this feature, specify a system root that begins
1215 with the `remote:' prefix, either via the `set sysroot' command or via
1216 the `--with-sysroot' configure-time option.
1218 * "info sharedlibrary" now takes an optional regex of libraries to show,
1219 and it now reports if a shared library has no debugging information.
1221 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1222 now complete on file names.
1224 * When completing in expressions, gdb will attempt to limit
1225 completions to allowable structure or union fields, where appropriate.
1226 For instance, consider:
1228 # struct example { int f1; double f2; };
1229 # struct example variable;
1232 If the user types TAB at the end of this command line, the available
1233 completions will be "f1" and "f2".
1235 * Inlined functions are now supported. They show up in backtraces, and
1236 the "step", "next", and "finish" commands handle them automatically.
1238 * GDB now supports the token-splicing (##) and stringification (#)
1239 operators when expanding macros. It also supports variable-arity
1242 * GDB now supports inspecting extra signal information, exported by
1243 the new $_siginfo convenience variable. The feature is currently
1244 implemented on linux ARM, i386 and amd64.
1246 * GDB can now display the VFP floating point registers and NEON vector
1247 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1248 can provide these registers (requires Linux 2.6.30 or later). Remote
1249 and simulator targets may also provide them.
1251 * New remote packets
1254 Search memory for a sequence of bytes.
1257 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1258 operation over reliable transport links. Use of this packet is
1259 controlled by the `set remote noack-packet' command.
1262 Kill the process with the specified process ID. Use this in preference
1263 to `k' when multiprocess protocol extensions are supported.
1266 Obtains additional operating system information
1270 Read or write additional signal information.
1272 * Removed remote protocol undocumented extension
1274 An undocumented extension to the remote protocol's `S' stop reply
1275 packet that permited the stub to pass a process id was removed.
1276 Remote servers should use the `T' stop reply packet instead.
1278 * GDB now supports multiple function calling conventions according to the
1279 DWARF-2 DW_AT_calling_convention function attribute.
1281 * The SH target utilizes the aforementioned change to distinguish between gcc
1282 and Renesas calling convention. It also adds the new CLI commands
1283 `set/show sh calling-convention'.
1285 * GDB can now read compressed debug sections, as produced by GNU gold
1286 with the --compress-debug-sections=zlib flag.
1288 * 64-bit core files are now supported on AIX.
1290 * Thread switching is now supported on Tru64.
1292 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1293 which will be allocated using malloc later in program execution.
1295 * The qXfer:libraries:read remote procotol packet now allows passing a
1296 list of section offsets.
1298 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1299 conditions handling signals delivered during attach or thread creation
1300 have also been fixed.
1302 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1303 From the user's standpoint, all unqualified instances of True and False
1304 are treated as the standard definitions, regardless of context.
1306 * GDB now parses C++ symbol and type names more flexibly. For
1309 template<typename T> class C { };
1312 GDB will now correctly handle all of:
1314 ptype C<char const *>
1315 ptype C<char const*>
1316 ptype C<const char *>
1317 ptype C<const char*>
1319 * New features in the GDB remote stub, gdbserver
1321 - The "--wrapper" command-line argument tells gdbserver to use a
1322 wrapper program to launch programs for debugging.
1324 - On PowerPC and S/390 targets, it is now possible to use a single
1325 gdbserver executable to debug both 32-bit and 64-bit programs.
1326 (This requires gdbserver itself to be built as a 64-bit executable.)
1328 - gdbserver uses the new noack protocol mode for TCP connections to
1329 reduce communications latency, if also supported and enabled in GDB.
1331 - Support for the sparc64-linux-gnu target is now included in
1334 - The amd64-linux build of gdbserver now supports debugging both
1335 32-bit and 64-bit programs.
1337 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1338 now support hardware watchpoints, and will use them automatically
1343 GDB now has support for scripting using Python. Whether this is
1344 available is determined at configure time.
1346 New GDB commands can now be written in Python.
1348 * Ada tasking support
1350 Ada tasks can now be inspected in GDB. The following commands have
1354 Print the list of Ada tasks.
1356 Print detailed information about task number N.
1358 Print the task number of the current task.
1360 Switch the context of debugging to task number N.
1362 * Support for user-defined prefixed commands. The "define" command can
1363 add new commands to existing prefixes, e.g. "target".
1365 * Multi-inferior, multi-process debugging.
1367 GDB now has generalized support for multi-inferior debugging. See
1368 "Debugging Multiple Inferiors" in the manual for more information.
1369 Although availability still depends on target support, the command
1370 set is more uniform now. The GNU/Linux specific multi-forks support
1371 has been migrated to this new framework. This implied some user
1372 visible changes; see "New commands" and also "Removed commands"
1375 * Target descriptions can now describe the target OS ABI. See the
1376 "Target Description Format" section in the user manual for more
1379 * Target descriptions can now describe "compatible" architectures
1380 to indicate that the target can execute applications for a different
1381 architecture in addition to those for the main target architecture.
1382 See the "Target Description Format" section in the user manual for
1385 * Multi-architecture debugging.
1387 GDB now includes general supports for debugging applications on
1388 hybrid systems that use more than one single processor architecture
1389 at the same time. Each such hybrid architecture still requires
1390 specific support to be added. The only hybrid architecture supported
1391 in this version of GDB is the Cell Broadband Engine.
1393 * GDB now supports integrated debugging of Cell/B.E. applications that
1394 use both the PPU and SPU architectures. To enable support for hybrid
1395 Cell/B.E. debugging, you need to configure GDB to support both the
1396 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1397 --enable-targets configure option.
1399 * Non-stop mode debugging.
1401 For some targets, GDB now supports an optional mode of operation in
1402 which you can examine stopped threads while other threads continue
1403 to execute freely. This is referred to as non-stop mode, with the
1404 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1405 section in the user manual for more information.
1407 To be able to support remote non-stop debugging, a remote stub needs
1408 to implement the non-stop mode remote protocol extensions, as
1409 described in the "Remote Non-Stop" section of the user manual. The
1410 GDB remote stub, gdbserver, has been adjusted to support these
1411 extensions on linux targets.
1413 * New commands (for set/show, see "New options" below)
1415 catch syscall [NAME(S) | NUMBER(S)]
1416 Catch system calls. Arguments, which should be names of system
1417 calls or their numbers, mean catch only those syscalls. Without
1418 arguments, every syscall will be caught. When the inferior issues
1419 any of the specified syscalls, GDB will stop and announce the system
1420 call, both when it is called and when its call returns. This
1421 feature is currently available with a native GDB running on the
1422 Linux Kernel, under the following architectures: x86, x86_64,
1423 PowerPC and PowerPC64.
1425 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1427 Search memory for a sequence of bytes.
1429 maint set python print-stack
1430 maint show python print-stack
1431 Show a stack trace when an error is encountered in a Python script.
1434 Invoke CODE by passing it to the Python interpreter.
1439 These allow macros to be defined, undefined, and listed
1443 Show operating system information about processes.
1446 List the inferiors currently under GDB's control.
1449 Switch focus to inferior number NUM.
1452 Detach from inferior number NUM.
1455 Kill inferior number NUM.
1459 set spu stop-on-load
1460 show spu stop-on-load
1461 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1463 set spu auto-flush-cache
1464 show spu auto-flush-cache
1465 Control whether to automatically flush the software-managed cache
1466 during Cell/B.E. debugging.
1468 set sh calling-convention
1469 show sh calling-convention
1470 Control the calling convention used when calling SH target functions.
1473 show debug timestamp
1474 Control display of timestamps with GDB debugging output.
1476 set disassemble-next-line
1477 show disassemble-next-line
1478 Control display of disassembled source lines or instructions when
1481 set remote noack-packet
1482 show remote noack-packet
1483 Set/show the use of remote protocol QStartNoAckMode packet. See above
1484 under "New remote packets."
1486 set remote query-attached-packet
1487 show remote query-attached-packet
1488 Control use of remote protocol `qAttached' (query-attached) packet.
1490 set remote read-siginfo-object
1491 show remote read-siginfo-object
1492 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1495 set remote write-siginfo-object
1496 show remote write-siginfo-object
1497 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1500 set remote reverse-continue
1501 show remote reverse-continue
1502 Control use of remote protocol 'bc' (reverse-continue) packet.
1504 set remote reverse-step
1505 show remote reverse-step
1506 Control use of remote protocol 'bs' (reverse-step) packet.
1508 set displaced-stepping
1509 show displaced-stepping
1510 Control displaced stepping mode. Displaced stepping is a way to
1511 single-step over breakpoints without removing them from the debuggee.
1512 Also known as "out-of-line single-stepping".
1515 show debug displaced
1516 Control display of debugging info for displaced stepping.
1518 maint set internal-error
1519 maint show internal-error
1520 Control what GDB does when an internal error is detected.
1522 maint set internal-warning
1523 maint show internal-warning
1524 Control what GDB does when an internal warning is detected.
1529 Use a wrapper program to launch programs for debugging.
1531 set multiple-symbols (all|ask|cancel)
1532 show multiple-symbols
1533 The value of this variable can be changed to adjust the debugger behavior
1534 when an expression or a breakpoint location contains an ambiguous symbol
1535 name (an overloaded function name, for instance).
1537 set breakpoint always-inserted
1538 show breakpoint always-inserted
1539 Keep breakpoints always inserted in the target, as opposed to inserting
1540 them when resuming the target, and removing them when the target stops.
1541 This option can improve debugger performance on slow remote targets.
1543 set arm fallback-mode (arm|thumb|auto)
1544 show arm fallback-mode
1545 set arm force-mode (arm|thumb|auto)
1547 These commands control how ARM GDB determines whether instructions
1548 are ARM or Thumb. The default for both settings is auto, which uses
1549 the current CPSR value for instructions without symbols; previous
1550 versions of GDB behaved as if "set arm fallback-mode arm".
1552 set disable-randomization
1553 show disable-randomization
1554 Standalone programs run with the virtual address space randomization enabled
1555 by default on some platforms. This option keeps the addresses stable across
1556 multiple debugging sessions.
1560 Control whether other threads are stopped or not when some thread hits
1565 Requests that asynchronous execution is enabled in the target, if available.
1566 In this case, it's possible to resume target in the background, and interact
1567 with GDB while the target is running. "show target-async" displays the
1568 current state of asynchronous execution of the target.
1570 set target-wide-charset
1571 show target-wide-charset
1572 The target-wide-charset is the name of the character set that GDB
1573 uses when printing characters whose type is wchar_t.
1575 set tcp auto-retry (on|off)
1577 set tcp connect-timeout
1578 show tcp connect-timeout
1579 These commands allow GDB to retry failed TCP connections to a remote stub
1580 with a specified timeout period; this is useful if the stub is launched
1581 in parallel with GDB but may not be ready to accept connections immediately.
1583 set libthread-db-search-path
1584 show libthread-db-search-path
1585 Control list of directories which GDB will search for appropriate
1588 set schedule-multiple (on|off)
1589 show schedule-multiple
1590 Allow GDB to resume all threads of all processes or only threads of
1591 the current process.
1595 Use more aggressive caching for accesses to the stack. This improves
1596 performance of remote debugging (particularly backtraces) without
1597 affecting correctness.
1599 set interactive-mode (on|off|auto)
1600 show interactive-mode
1601 Control whether GDB runs in interactive mode (on) or not (off).
1602 When in interactive mode, GDB waits for the user to answer all
1603 queries. Otherwise, GDB does not wait and assumes the default
1604 answer. When set to auto (the default), GDB determines which
1605 mode to use based on the stdin settings.
1610 For program forks, this is replaced by the new more generic `info
1611 inferiors' command. To list checkpoints, you can still use the
1612 `info checkpoints' command, which was an alias for the `info forks'
1616 Replaced by the new `inferior' command. To switch between
1617 checkpoints, you can still use the `restart' command, which was an
1618 alias for the `fork' command.
1621 This is removed, since some targets don't have a notion of
1622 processes. To switch between processes, you can still use the
1623 `inferior' command using GDB's own inferior number.
1626 For program forks, this is replaced by the new more generic `kill
1627 inferior' command. To delete a checkpoint, you can still use the
1628 `delete checkpoint' command, which was an alias for the `delete
1632 For program forks, this is replaced by the new more generic `detach
1633 inferior' command. To detach a checkpoint, you can still use the
1634 `detach checkpoint' command, which was an alias for the `detach
1637 * New native configurations
1639 x86/x86_64 Darwin i[34567]86-*-darwin*
1641 x86_64 MinGW x86_64-*-mingw*
1645 Lattice Mico32 lm32-*
1646 x86 DICOS i[34567]86-*-dicos*
1647 x86_64 DICOS x86_64-*-dicos*
1650 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1651 (mingw32ce) debugging.
1657 These commands were actually not implemented on any target.
1659 *** Changes in GDB 6.8
1661 * New native configurations
1663 NetBSD/hppa hppa*-*netbsd*
1664 Xtensa GNU/Linux xtensa*-*-linux*
1668 NetBSD/hppa hppa*-*-netbsd*
1669 Xtensa GNU/Lunux xtensa*-*-linux*
1671 * Change in command line behavior -- corefiles vs. process ids.
1673 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1674 attaching to process NUMBER fails, GDB no longer attempts to open a
1675 core file named NUMBER. Attaching to a program using the -c option
1676 is no longer supported. Instead, use the '-p' or '--pid' options.
1678 * GDB can now be built as a native debugger for debugging Windows x86
1679 (mingw32) Portable Executable (PE) programs.
1681 * Pending breakpoints no longer change their number when their address
1684 * GDB now supports breakpoints with multiple locations,
1685 including breakpoints on C++ constructors, inside C++ templates,
1686 and in inlined functions.
1688 * GDB's ability to debug optimized code has been improved. GDB more
1689 accurately identifies function bodies and lexical blocks that occupy
1690 more than one contiguous range of addresses.
1692 * Target descriptions can now describe registers for PowerPC.
1694 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1695 registers on PowerPC targets.
1697 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1698 targets even when the libthread_db library is not available.
1700 * The GDB remote stub, gdbserver, now supports the new file transfer
1701 commands (remote put, remote get, and remote delete).
1703 * The GDB remote stub, gdbserver, now supports run and attach in
1704 extended-remote mode.
1706 * hppa*64*-*-hpux11* target broken
1707 The debugger is unable to start a program and fails with the following
1708 error: "Error trying to get information about dynamic linker".
1709 The gdb-6.7 release is also affected.
1711 * GDB now supports the --enable-targets= configure option to allow
1712 building a single GDB executable that supports multiple remote
1713 target architectures.
1715 * GDB now supports debugging C and C++ programs which use the
1716 Decimal Floating Point extension. In addition, the PowerPC target
1717 now has a set of pseudo-registers to inspect decimal float values
1718 stored in two consecutive float registers.
1720 * The -break-insert MI command can optionally create pending
1723 * Improved support for debugging Ada
1724 Many improvements to the Ada language support have been made. These
1726 - Better support for Ada2005 interface types
1727 - Improved handling of arrays and slices in general
1728 - Better support for Taft-amendment types
1729 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1731 - Improved command completion in Ada
1734 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1739 set print frame-arguments (all|scalars|none)
1740 show print frame-arguments
1741 The value of this variable can be changed to control which argument
1742 values should be printed by the debugger when displaying a frame.
1747 Transfer files to and from a remote target, and delete remote files.
1754 Transfer files to and from a remote target, and delete remote files.
1756 * New remote packets
1763 Open, close, read, write, and delete files on the remote system.
1766 Attach to an existing process on the remote system, in extended-remote
1770 Run a new process on the remote system, in extended-remote mode.
1772 *** Changes in GDB 6.7
1774 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1775 bfd, libiberty and opcodes, as revealed by static analysis donated by
1776 Coverity, Inc. (http://scan.coverity.com).
1778 * When looking up multiply-defined global symbols, GDB will now prefer the
1779 symbol definition in the current shared library if it was built using the
1780 -Bsymbolic linker option.
1782 * When the Text User Interface (TUI) is not configured, GDB will now
1783 recognize the -tui command-line option and print a message that the TUI
1786 * The GDB remote stub, gdbserver, now has lower overhead for high
1787 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1789 * GDB for MIPS targets now autodetects whether a remote target provides
1790 32-bit or 64-bit register values.
1792 * Support for C++ member pointers has been improved.
1794 * GDB now understands XML target descriptions, which specify the
1795 target's overall architecture. GDB can read a description from
1796 a local file or over the remote serial protocol.
1798 * Vectors of single-byte data use a new integer type which is not
1799 automatically displayed as character or string data.
1801 * The /s format now works with the print command. It displays
1802 arrays of single-byte integers and pointers to single-byte integers
1805 * Target descriptions can now describe target-specific registers,
1806 for architectures which have implemented the support (currently
1807 only ARM, M68K, and MIPS).
1809 * GDB and the GDB remote stub, gdbserver, now support the XScale
1812 * The GDB remote stub, gdbserver, has been updated to support
1813 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1814 has been rewritten to use the standard GDB remote protocol.
1816 * GDB can now step into C++ functions which are called through thunks.
1818 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1820 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1821 layout. It also supports a TextSeg= and DataSeg= response when only
1822 segment base addresses (rather than offsets) are available.
1824 * The /i format now outputs any trailing branch delay slot instructions
1825 immediately following the last instruction within the count specified.
1827 * The GDB remote protocol "T" stop reply packet now supports a
1828 "library" response. Combined with the new "qXfer:libraries:read"
1829 packet, this response allows GDB to debug shared libraries on targets
1830 where the operating system manages the list of loaded libraries (e.g.
1831 Windows and SymbianOS).
1833 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1834 (DLLs) on Windows and Windows CE targets.
1836 * GDB now supports a faster verification that a .debug file matches its binary
1837 according to its build-id signature, if the signature is present.
1843 Enable or disable hardware flow control (RTS/CTS) on the serial port
1844 when debugging using remote targets.
1846 set mem inaccessible-by-default
1847 show mem inaccessible-by-default
1848 If the target supplies a memory map, for instance via the remote
1849 protocol's "qXfer:memory-map:read" packet, setting this variable
1850 prevents GDB from accessing memory outside the memory map. This
1851 is useful for targets with memory mapped registers or which react
1852 badly to accesses of unmapped address space.
1854 set breakpoint auto-hw
1855 show breakpoint auto-hw
1856 If the target supplies a memory map, for instance via the remote
1857 protocol's "qXfer:memory-map:read" packet, setting this variable
1858 lets GDB use hardware breakpoints automatically for memory regions
1859 where it can not use software breakpoints. This covers both the
1860 "break" command and internal breakpoints used for other commands
1861 including "next" and "finish".
1864 catch exception unhandled
1865 Stop the program execution when Ada exceptions are raised.
1868 Stop the program execution when an Ada assertion failed.
1872 Set an alternate system root for target files. This is a more
1873 general version of "set solib-absolute-prefix", which is now
1874 an alias to "set sysroot".
1877 Provide extended SPU facility status information. This set of
1878 commands is available only when debugging the Cell/B.E. SPU
1881 * New native configurations
1883 OpenBSD/sh sh*-*openbsd*
1886 unset tdesc filename
1888 Use the specified local file as an XML target description, and do
1889 not query the target for its built-in description.
1893 OpenBSD/sh sh*-*-openbsd*
1894 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1895 Toshiba Media Processor mep-elf
1897 * New remote packets
1900 Ignore the specified signals; pass them directly to the debugged program
1901 without stopping other threads or reporting them to GDB.
1903 qXfer:features:read:
1904 Read an XML target description from the target, which describes its
1909 Read or write contents of an spufs file on the target system. These
1910 packets are available only on the Cell/B.E. SPU architecture.
1912 qXfer:libraries:read:
1913 Report the loaded shared libraries. Combined with new "T" packet
1914 response, this packet allows GDB to debug shared libraries on
1915 targets where the operating system manages the list of loaded
1916 libraries (e.g. Windows and SymbianOS).
1920 Support for these obsolete configurations has been removed.
1928 i[34567]86-*-lynxos*
1929 i[34567]86-*-netware*
1930 i[34567]86-*-sco3.2v5*
1931 i[34567]86-*-sco3.2v4*
1933 i[34567]86-*-sysv4.2*
1936 i[34567]86-*-unixware2*
1937 i[34567]86-*-unixware*
1946 * Other removed features
1953 Various m68k-only ROM monitors.
1960 Various Renesas ROM monitors and debugging interfaces for SH and
1965 Support for a Macraigor serial interface to on-chip debugging.
1966 GDB does not directly support the newer parallel or USB
1971 A debug information format. The predecessor to DWARF 2 and
1972 DWARF 3, which are still supported.
1974 Support for the HP aCC compiler on HP-UX/PA-RISC
1976 SOM-encapsulated symbolic debugging information, automatic
1977 invocation of pxdb, and the aCC custom C++ ABI. This does not
1978 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1979 with aCC can still be debugged on an assembly level.
1981 MIPS ".pdr" sections
1983 A MIPS-specific format used to describe stack frame layout
1984 in debugging information.
1988 GDB could work with an older version of Guile to debug
1989 the interpreter and Scheme programs running in it.
1991 set mips stack-arg-size
1992 set mips saved-gpreg-size
1994 Use "set mips abi" to control parameter passing for MIPS.
1996 *** Changes in GDB 6.6
2001 Cell Broadband Engine SPU spu-elf
2003 * GDB can now be configured as a cross-debugger targeting native Windows
2004 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2005 running on a Windows system over TCP/IP to debug Windows programs.
2007 * The GDB remote stub, gdbserver, has been updated to support Windows and
2008 Cygwin debugging. Both single-threaded and multi-threaded programs are
2011 * The "set trust-readonly-sections" command works again. This command was
2012 broken in GDB 6.3, 6.4, and 6.5.
2014 * The "load" command now supports writing to flash memory, if the remote
2015 stub provides the required support.
2017 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2018 longer requires symbolic debug information (e.g. DWARF-2).
2023 unset substitute-path
2024 show substitute-path
2025 Manage a list of substitution rules that GDB uses to rewrite the name
2026 of the directories where the sources are located. This can be useful
2027 for instance when the sources were moved to a different location
2028 between compilation and debugging.
2032 Print each CLI command as it is executed. Each command is prefixed with
2033 a number of `+' symbols representing the nesting depth.
2034 The source command now has a `-v' option to enable the same feature.
2038 The ARM Demon monitor support (RDP protocol, "target rdp").
2040 Kernel Object Display, an embedded debugging feature which only worked with
2041 an obsolete version of Cisco IOS.
2043 The 'set download-write-size' and 'show download-write-size' commands.
2045 * New remote packets
2048 Tell a stub about GDB client features, and request remote target features.
2049 The first feature implemented is PacketSize, which allows the target to
2050 specify the size of packets it can handle - to minimize the number of
2051 packets required and improve performance when connected to a remote
2055 Fetch an OS auxilliary vector from the remote stub. This packet is a
2056 more efficient replacement for qPart:auxv:read.
2058 qXfer:memory-map:read:
2059 Fetch a memory map from the remote stub, including information about
2060 RAM, ROM, and flash memory devices.
2065 Erase and program a flash memory device.
2067 * Removed remote packets
2070 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2071 used it, and only gdbserver implemented it.
2073 *** Changes in GDB 6.5
2077 Renesas M32C/M16C m32c-elf
2079 Morpho Technologies ms1 ms1-elf
2083 init-if-undefined Initialize a convenience variable, but
2084 only if it doesn't already have a value.
2086 The following commands are presently only implemented for native GNU/Linux:
2088 checkpoint Save a snapshot of the program state.
2090 restart <n> Return the program state to a
2091 previously saved state.
2093 info checkpoints List currently saved checkpoints.
2095 delete-checkpoint <n> Delete a previously saved checkpoint.
2097 set|show detach-on-fork Tell gdb whether to detach from a newly
2098 forked process, or to keep debugging it.
2100 info forks List forks of the user program that
2101 are available to be debugged.
2103 fork <n> Switch to debugging one of several
2104 forks of the user program that are
2105 available to be debugged.
2107 delete-fork <n> Delete a fork from the list of forks
2108 that are available to be debugged (and
2109 kill the forked process).
2111 detach-fork <n> Delete a fork from the list of forks
2112 that are available to be debugged (and
2113 allow the process to continue).
2117 Morpho Technologies ms2 ms1-elf
2119 * Improved Windows host support
2121 GDB now builds as a cross debugger hosted on i686-mingw32, including
2122 native console support, and remote communications using either
2123 network sockets or serial ports.
2125 * Improved Modula-2 language support
2127 GDB can now print most types in the Modula-2 syntax. This includes:
2128 basic types, set types, record types, enumerated types, range types,
2129 pointer types and ARRAY types. Procedure var parameters are correctly
2130 printed and hexadecimal addresses and character constants are also
2131 written in the Modula-2 syntax. Best results can be obtained by using
2132 GNU Modula-2 together with the -gdwarf-2 command line option.
2136 The ARM rdi-share module.
2138 The Netware NLM debug server.
2140 *** Changes in GDB 6.4
2142 * New native configurations
2144 OpenBSD/arm arm*-*-openbsd*
2145 OpenBSD/mips64 mips64-*-openbsd*
2149 Morpho Technologies ms1 ms1-elf
2151 * New command line options
2153 --batch-silent As for --batch, but totally silent.
2154 --return-child-result The debugger will exist with the same value
2155 the child (debugged) program exited with.
2156 --eval-command COMMAND, -ex COMMAND
2157 Execute a single GDB CLI command. This may be
2158 specified multiple times and in conjunction
2159 with the --command (-x) option.
2161 * Deprecated commands removed
2163 The following commands, that were deprecated in 2000, have been
2167 set|show arm disassembly-flavor set|show arm disassembler
2168 othernames set arm disassembler
2169 set|show remotedebug set|show debug remote
2170 set|show archdebug set|show debug arch
2171 set|show eventdebug set|show debug event
2174 * New BSD user-level threads support
2176 It is now possible to debug programs using the user-level threads
2177 library on OpenBSD and FreeBSD. Currently supported (target)
2180 FreeBSD/amd64 x86_64-*-freebsd*
2181 FreeBSD/i386 i386-*-freebsd*
2182 OpenBSD/i386 i386-*-openbsd*
2184 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2185 are not yet supported.
2187 * New support for Matsushita MN10300 w/sim added
2188 (Work in progress). mn10300-elf.
2190 * REMOVED configurations and files
2192 VxWorks and the XDR protocol *-*-vxworks
2193 Motorola MCORE mcore-*-*
2194 National Semiconductor NS32000 ns32k-*-*
2196 * New "set print array-indexes" command
2198 After turning this setting "on", GDB prints the index of each element
2199 when displaying arrays. The default is "off" to preserve the previous
2202 * VAX floating point support
2204 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2206 * User-defined command support
2208 In addition to using $arg0..$arg9 for argument passing, it is now possible
2209 to use $argc to determine now many arguments have been passed. See the
2210 section on user-defined commands in the user manual for more information.
2212 *** Changes in GDB 6.3:
2214 * New command line option
2216 GDB now accepts -l followed by a number to set the timeout for remote
2219 * GDB works with GCC -feliminate-dwarf2-dups
2221 GDB now supports a more compact representation of DWARF-2 debug
2222 information using DW_FORM_ref_addr references. These are produced
2223 by GCC with the option -feliminate-dwarf2-dups and also by some
2224 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2225 to use -feliminate-dwarf2-dups.
2227 * Internationalization
2229 When supported by the host system, GDB will be built with
2230 internationalization (libintl). The task of marking up the sources is
2231 continued, we're looking forward to our first translation.
2235 Initial support for debugging programs compiled with the GNAT
2236 implementation of the Ada programming language has been integrated
2237 into GDB. In this release, support is limited to expression evaluation.
2239 * New native configurations
2241 GNU/Linux/m32r m32r-*-linux-gnu
2245 GDB's remote protocol now includes support for the 'p' packet. This
2246 packet is used to fetch individual registers from a remote inferior.
2248 * END-OF-LIFE registers[] compatibility module
2250 GDB's internal register infrastructure has been completely rewritten.
2251 The new infrastructure making possible the implementation of key new
2252 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2255 GDB 6.3 will be the last release to include the the registers[]
2256 compatibility module that allowed out-of-date configurations to
2257 continue to work. This change directly impacts the following
2267 powerpc bdm protocol
2269 Unless there is activity to revive these configurations, they will be
2270 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2272 * OBSOLETE configurations and files
2274 Configurations that have been declared obsolete in this release have
2275 been commented out. Unless there is activity to revive these
2276 configurations, the next release of GDB will have their sources
2277 permanently REMOVED.
2286 *** Changes in GDB 6.2.1:
2288 * MIPS `break main; run' gave an heuristic-fence-post warning
2290 When attempting to run even a simple program, a warning about
2291 heuristic-fence-post being hit would be reported. This problem has
2294 * MIPS IRIX 'long double' crashed GDB
2296 When examining a long double variable, GDB would get a segmentation
2297 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2298 IRIX long double values).
2302 A bug in the VAX stack code was causing problems with the "next"
2303 command. This problem has been fixed.
2305 *** Changes in GDB 6.2:
2307 * Fix for ``many threads''
2309 On GNU/Linux systems that use the NPTL threads library, a program
2310 rapidly creating and deleting threads would confuse GDB leading to the
2313 ptrace: No such process.
2314 thread_db_get_info: cannot get thread info: generic error
2316 This problem has been fixed.
2318 * "-async" and "-noasync" options removed.
2320 Support for the broken "-noasync" option has been removed (it caused
2323 * New ``start'' command.
2325 This command runs the program until the begining of the main procedure.
2327 * New BSD Kernel Data Access Library (libkvm) interface
2329 Using ``target kvm'' it is now possible to debug kernel core dumps and
2330 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2331 platforms. Currently supported (native-only) configurations are:
2333 FreeBSD/amd64 x86_64-*-freebsd*
2334 FreeBSD/i386 i?86-*-freebsd*
2335 NetBSD/i386 i?86-*-netbsd*
2336 NetBSD/m68k m68*-*-netbsd*
2337 NetBSD/sparc sparc-*-netbsd*
2338 OpenBSD/amd64 x86_64-*-openbsd*
2339 OpenBSD/i386 i?86-*-openbsd*
2340 OpenBSD/m68k m68*-openbsd*
2341 OpenBSD/sparc sparc-*-openbsd*
2343 * Signal trampoline code overhauled
2345 Many generic problems with GDB's signal handling code have been fixed.
2346 These include: backtraces through non-contiguous stacks; recognition
2347 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2348 call; backtrace through a signal trampoline; step into and out of
2349 signal handlers; and single-stepping in the signal trampoline.
2351 Please note that kernel bugs are a limiting factor here. These
2352 features have been shown to work on an s390 GNU/Linux system that
2353 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2355 * Cygwin support for DWARF 2 added.
2357 * New native configurations
2359 GNU/Linux/hppa hppa*-*-linux*
2360 OpenBSD/hppa hppa*-*-openbsd*
2361 OpenBSD/m68k m68*-*-openbsd*
2362 OpenBSD/m88k m88*-*-openbsd*
2363 OpenBSD/powerpc powerpc-*-openbsd*
2364 NetBSD/vax vax-*-netbsd*
2365 OpenBSD/vax vax-*-openbsd*
2367 * END-OF-LIFE frame compatibility module
2369 GDB's internal frame infrastructure has been completely rewritten.
2370 The new infrastructure making it possible to support key new features
2371 including DWARF 2 Call Frame Information. To aid in the task of
2372 migrating old configurations to this new infrastructure, a
2373 compatibility module, that allowed old configurations to continue to
2374 work, was also included.
2376 GDB 6.2 will be the last release to include this frame compatibility
2377 module. This change directly impacts the following configurations:
2387 Unless there is activity to revive these configurations, they will be
2388 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2390 * REMOVED configurations and files
2392 Sun 3, running SunOS 3 m68*-*-sunos3*
2393 Sun 3, running SunOS 4 m68*-*-sunos4*
2394 Sun 2, running SunOS 3 m68000-*-sunos3*
2395 Sun 2, running SunOS 4 m68000-*-sunos4*
2396 Motorola 680x0 running LynxOS m68*-*-lynxos*
2397 AT&T 3b1/Unix pc m68*-att-*
2398 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2399 decstation mips-dec-* mips-little-*
2400 riscos mips-*-riscos* mips-*-sysv*
2401 sonymips mips-sony-*
2402 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2404 *** Changes in GDB 6.1.1:
2406 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2408 The TUI (Text-mode User Interface) is now built as part of a default
2409 GDB configuration. It is enabled by either selecting the TUI with the
2410 command line option "-i=tui" or by running the separate "gdbtui"
2411 program. For more information on the TUI, see the manual "Debugging
2414 * Pending breakpoint support (also included in GDB 6.1)
2416 Support has been added to allow you to specify breakpoints in shared
2417 libraries that have not yet been loaded. If a breakpoint location
2418 cannot be found, and the "breakpoint pending" option is set to auto,
2419 GDB queries you if you wish to make the breakpoint pending on a future
2420 shared-library load. If and when GDB resolves the breakpoint symbol,
2421 the pending breakpoint is removed as one or more regular breakpoints
2424 Pending breakpoints are very useful for GCJ Java debugging.
2426 * Fixed ISO-C build problems
2428 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2429 non ISO-C code that stopped them being built using a more strict ISO-C
2430 compiler (e.g., IBM's C compiler).
2432 * Fixed build problem on IRIX 5
2434 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2435 wasn't able to compile compile on an IRIX 5 system.
2437 * Added execute permission to gdb/gdbserver/configure
2439 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2440 permission. This bug would cause configure to fail on a number of
2441 systems (Solaris, IRIX). Ref: server/519.
2443 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2445 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2446 has been updated to use constant array sizes.
2448 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2450 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2451 its generated DWARF Call Frame Info. This encoding was causing GDB to
2452 panic, that panic has been fixed. Ref: gdb/1628.
2454 * Fixed a problem when examining parameters in shared library code.
2456 When examining parameters in optimized shared library code generated
2457 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2458 not available''. GDB now correctly displays the variable's value.
2460 *** Changes in GDB 6.1:
2462 * Removed --with-mmalloc
2464 Support for the mmalloc memory manager has been removed, as it
2465 conflicted with the internal gdb byte cache.
2467 * Changes in AMD64 configurations
2469 The AMD64 target now includes the %cs and %ss registers. As a result
2470 the AMD64 remote protocol has changed; this affects the floating-point
2471 and SSE registers. If you rely on those registers for your debugging,
2472 you should upgrade gdbserver on the remote side.
2474 * Revised SPARC target
2476 The SPARC target has been completely revised, incorporating the
2477 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2478 support for LynxOS and SunOS 4 has been dropped. Calling functions
2479 from within GDB on operating systems with a non-executable stack
2480 (Solaris, OpenBSD) now works.
2484 GDB has a new C++ demangler which does a better job on the mangled
2485 names generated by current versions of g++. It also runs faster, so
2486 with this and other changes gdb should now start faster on large C++
2489 * DWARF 2 Location Expressions
2491 GDB support for location expressions has been extended to support function
2492 arguments and frame bases. Older versions of GDB could crash when they
2495 * C++ nested types and namespaces
2497 GDB's support for nested types and namespaces in C++ has been
2498 improved, especially if you use the DWARF 2 debugging format. (This
2499 is the default for recent versions of GCC on most platforms.)
2500 Specifically, if you have a class "Inner" defined within a class or
2501 namespace "Outer", then GDB realizes that the class's name is
2502 "Outer::Inner", not simply "Inner". This should greatly reduce the
2503 frequency of complaints about not finding RTTI symbols. In addition,
2504 if you are stopped at inside of a function defined within a namespace,
2505 GDB modifies its name lookup accordingly.
2507 * New native configurations
2509 NetBSD/amd64 x86_64-*-netbsd*
2510 OpenBSD/amd64 x86_64-*-openbsd*
2511 OpenBSD/alpha alpha*-*-openbsd*
2512 OpenBSD/sparc sparc-*-openbsd*
2513 OpenBSD/sparc64 sparc64-*-openbsd*
2515 * New debugging protocols
2517 M32R with SDI protocol m32r-*-elf*
2519 * "set prompt-escape-char" command deleted.
2521 The command "set prompt-escape-char" has been deleted. This command,
2522 and its very obscure effet on GDB's prompt, was never documented,
2523 tested, nor mentioned in the NEWS file.
2525 * OBSOLETE configurations and files
2527 Configurations that have been declared obsolete in this release have
2528 been commented out. Unless there is activity to revive these
2529 configurations, the next release of GDB will have their sources
2530 permanently REMOVED.
2532 Sun 3, running SunOS 3 m68*-*-sunos3*
2533 Sun 3, running SunOS 4 m68*-*-sunos4*
2534 Sun 2, running SunOS 3 m68000-*-sunos3*
2535 Sun 2, running SunOS 4 m68000-*-sunos4*
2536 Motorola 680x0 running LynxOS m68*-*-lynxos*
2537 AT&T 3b1/Unix pc m68*-att-*
2538 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2539 decstation mips-dec-* mips-little-*
2540 riscos mips-*-riscos* mips-*-sysv*
2541 sonymips mips-sony-*
2542 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2544 * REMOVED configurations and files
2546 SGI Irix-4.x mips-sgi-irix4 or iris4
2547 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2548 Z8000 simulator z8k-zilog-none or z8ksim
2549 Matsushita MN10200 w/simulator mn10200-*-*
2550 H8/500 simulator h8500-hitachi-hms or h8500hms
2551 HP/PA running BSD hppa*-*-bsd*
2552 HP/PA running OSF/1 hppa*-*-osf*
2553 HP/PA Pro target hppa*-*-pro*
2554 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2555 386BSD i[3456]86-*-bsd*
2556 Sequent family i[3456]86-sequent-sysv4*
2557 i[3456]86-sequent-sysv*
2558 i[3456]86-sequent-bsd*
2559 SPARC running LynxOS sparc-*-lynxos*
2560 SPARC running SunOS 4 sparc-*-sunos4*
2561 Tsqware Sparclet sparclet-*-*
2562 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2564 *** Changes in GDB 6.0:
2568 Support for debugging the Objective-C programming language has been
2569 integrated into GDB.
2571 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2573 DWARF 2's Call Frame Information makes available compiler generated
2574 information that more exactly describes the program's run-time stack.
2575 By using this information, GDB is able to provide more robust stack
2578 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2579 have been updated to use a new backtrace mechanism which includes
2580 DWARF 2 CFI support.
2584 GDB's remote protocol has been extended to include support for hosted
2585 file I/O (where the remote target uses GDB's file system). See GDB's
2586 remote protocol documentation for details.
2588 * All targets using the new architecture framework.
2590 All of GDB's targets have been updated to use the new internal
2591 architecture framework. The way is now open for future GDB releases
2592 to include cross-architecture native debugging support (i386 on amd64,
2595 * GNU/Linux's Thread Local Storage (TLS)
2597 GDB now includes support for for the GNU/Linux implementation of
2598 per-thread variables.
2600 * GNU/Linux's Native POSIX Thread Library (NPTL)
2602 GDB's thread code has been updated to work with either the new
2603 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2605 * Separate debug info.
2607 GDB, in conjunction with BINUTILS, now supports a mechanism for
2608 automatically loading debug information from a separate file. Instead
2609 of shipping full debug and non-debug versions of system libraries,
2610 system integrators can now instead ship just the stripped libraries
2611 and optional debug files.
2613 * DWARF 2 Location Expressions
2615 DWARF 2 Location Expressions allow the compiler to more completely
2616 describe the location of variables (even in optimized code) to the
2619 GDB now includes preliminary support for location expressions (support
2620 for DW_OP_piece is still missing).
2624 A number of long standing bugs that caused GDB to die while starting a
2625 Java application have been fixed. GDB's Java support is now
2626 considered "useable".
2628 * GNU/Linux support for fork, vfork, and exec.
2630 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2631 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2634 * GDB supports logging output to a file
2636 There are two new commands, "set logging" and "show logging", which can be
2637 used to capture GDB's output to a file.
2639 * The meaning of "detach" has changed for gdbserver
2641 The "detach" command will now resume the application, as documented. To
2642 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2645 * d10v, m68hc11 `regs' command deprecated
2647 The `info registers' command has been updated so that it displays the
2648 registers using a format identical to the old `regs' command.
2652 A new command, "maint set profile on/off", has been added. This command can
2653 be used to enable or disable profiling while running GDB, to profile a
2654 session or a set of commands. In addition there is a new configure switch,
2655 "--enable-profiling", which will cause GDB to be compiled with profiling
2656 data, for more informative profiling results.
2658 * Default MI syntax changed to "mi2".
2660 The default MI (machine interface) syntax, enabled by the command line
2661 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2662 "mi1", can be enabled by specifying the option "-i=mi1".
2664 Support for the original "mi0" syntax (included in GDB 5.0) has been
2667 Fix for gdb/192: removed extraneous space when displaying frame level.
2668 Fix for gdb/672: update changelist is now output in mi list format.
2669 Fix for gdb/702: a -var-assign that updates the value now shows up
2670 in a subsequent -var-update.
2672 * New native configurations.
2674 FreeBSD/amd64 x86_64-*-freebsd*
2676 * Multi-arched targets.
2678 HP/PA HPUX11 hppa*-*-hpux*
2679 Renesas M32R/D w/simulator m32r-*-elf*
2681 * OBSOLETE configurations and files
2683 Configurations that have been declared obsolete in this release have
2684 been commented out. Unless there is activity to revive these
2685 configurations, the next release of GDB will have their sources
2686 permanently REMOVED.
2688 Z8000 simulator z8k-zilog-none or z8ksim
2689 Matsushita MN10200 w/simulator mn10200-*-*
2690 H8/500 simulator h8500-hitachi-hms or h8500hms
2691 HP/PA running BSD hppa*-*-bsd*
2692 HP/PA running OSF/1 hppa*-*-osf*
2693 HP/PA Pro target hppa*-*-pro*
2694 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2695 Sequent family i[3456]86-sequent-sysv4*
2696 i[3456]86-sequent-sysv*
2697 i[3456]86-sequent-bsd*
2698 Tsqware Sparclet sparclet-*-*
2699 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2701 * REMOVED configurations and files
2704 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2705 IBM AIX PS/2 i[3456]86-*-aix
2706 i386 running Mach 3.0 i[3456]86-*-mach3*
2707 i386 running Mach i[3456]86-*-mach*
2708 i386 running OSF/1 i[3456]86-*osf1mk*
2709 HP/Apollo 68k Family m68*-apollo*-sysv*,
2711 m68*-hp-bsd*, m68*-hp-hpux*
2712 Argonaut Risc Chip (ARC) arc-*-*
2713 Mitsubishi D30V d30v-*-*
2714 Fujitsu FR30 fr30-*-elf*
2715 OS/9000 i[34]86-*-os9k
2716 I960 with MON960 i960-*-coff
2718 * MIPS $fp behavior changed
2720 The convenience variable $fp, for the MIPS, now consistently returns
2721 the address of the current frame's base. Previously, depending on the
2722 context, $fp could refer to either $sp or the current frame's base
2723 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2724 The GNU Source-Level Debugger''.
2726 *** Changes in GDB 5.3:
2728 * GNU/Linux shared library multi-threaded performance improved.
2730 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2731 `/proc', in preference to `ptrace' for memory reads. This may result
2732 in an improvement in the start-up time of multi-threaded, shared
2733 library applications when run under GDB. One GDB user writes: ``loads
2734 shared libs like mad''.
2736 * ``gdbserver'' now supports multi-threaded applications on some targets
2738 Support for debugging multi-threaded applications which use
2739 the GNU/Linux LinuxThreads package has been added for
2740 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2741 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2743 * GDB now supports C/C++ preprocessor macros.
2745 GDB now expands preprocessor macro invocations in C/C++ expressions,
2746 and provides various commands for showing macro definitions and how
2749 The new command `macro expand EXPRESSION' expands any macro
2750 invocations in expression, and shows the result.
2752 The new command `show macro MACRO-NAME' shows the definition of the
2753 macro named MACRO-NAME, and where it was defined.
2755 Most compilers don't include information about macros in the debugging
2756 information by default. In GCC 3.1, for example, you need to compile
2757 your program with the options `-gdwarf-2 -g3'. If the macro
2758 information is present in the executable, GDB will read it.
2760 * Multi-arched targets.
2762 DEC Alpha (partial) alpha*-*-*
2763 DEC VAX (partial) vax-*-*
2765 National Semiconductor NS32000 (partial) ns32k-*-*
2766 Motorola 68000 (partial) m68k-*-*
2767 Motorola MCORE mcore-*-*
2771 Fujitsu FRV architecture added by Red Hat frv*-*-*
2774 * New native configurations
2776 Alpha NetBSD alpha*-*-netbsd*
2777 SH NetBSD sh*-*-netbsdelf*
2778 MIPS NetBSD mips*-*-netbsd*
2779 UltraSPARC NetBSD sparc64-*-netbsd*
2781 * OBSOLETE configurations and files
2783 Configurations that have been declared obsolete in this release have
2784 been commented out. Unless there is activity to revive these
2785 configurations, the next release of GDB will have their sources
2786 permanently REMOVED.
2788 Mitsubishi D30V d30v-*-*
2789 OS/9000 i[34]86-*-os9k
2790 IBM AIX PS/2 i[3456]86-*-aix
2791 Fujitsu FR30 fr30-*-elf*
2792 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2793 Argonaut Risc Chip (ARC) arc-*-*
2794 i386 running Mach 3.0 i[3456]86-*-mach3*
2795 i386 running Mach i[3456]86-*-mach*
2796 i386 running OSF/1 i[3456]86-*osf1mk*
2797 HP/Apollo 68k Family m68*-apollo*-sysv*,
2799 m68*-hp-bsd*, m68*-hp-hpux*
2800 I960 with MON960 i960-*-coff
2802 * OBSOLETE languages
2804 CHILL, a Pascal like language used by telecommunications companies.
2806 * REMOVED configurations and files
2808 AMD 29k family via UDI a29k-amd-udi, udi29k
2809 A29K VxWorks a29k-*-vxworks
2810 AMD 29000 embedded, using EBMON a29k-none-none
2811 AMD 29000 embedded with COFF a29k-none-coff
2812 AMD 29000 embedded with a.out a29k-none-aout
2814 testsuite/gdb.hp/gdb.threads-hp/ directory
2816 * New command "set max-user-call-depth <nnn>"
2818 This command allows the user to limit the call depth of user-defined
2819 commands. The default is 1024.
2821 * Changes in FreeBSD/i386 native debugging.
2823 Support for the "generate-core-file" has been added.
2825 * New commands "dump", "append", and "restore".
2827 These commands allow data to be copied from target memory
2828 to a bfd-format or binary file (dump and append), and back
2829 from a file into memory (restore).
2831 * Improved "next/step" support on multi-processor Alpha Tru64.
2833 The previous single-step mechanism could cause unpredictable problems,
2834 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2835 of a software single-step mechanism prevents this.
2837 *** Changes in GDB 5.2.1:
2845 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2846 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2847 Fix, by Joel Brobecker imported from mainline.
2849 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2850 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2851 Fix, by Fred Fish, imported from mainline.
2853 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2854 Surprisingly enough, it works now.
2855 By Michal Ludvig, imported from mainline.
2857 i386 hardware watchpoint support:
2858 avoid misses on second run for some targets.
2859 By Pierre Muller, imported from mainline.
2861 *** Changes in GDB 5.2:
2863 * New command "set trust-readonly-sections on[off]".
2865 This command is a hint that tells gdb that read-only sections
2866 really are read-only (ie. that their contents will not change).
2867 In this mode, gdb will go to the object file rather than the
2868 target to read memory from read-only sections (such as ".text").
2869 This can be a significant performance improvement on some
2870 (notably embedded) targets.
2872 * New command "generate-core-file" (or "gcore").
2874 This new gdb command allows the user to drop a core file of the child
2875 process state at any time. So far it's been implemented only for
2876 GNU/Linux and Solaris, but should be relatively easily ported to other
2877 hosts. Argument is core file name (defaults to core.<pid>).
2879 * New command line option
2881 GDB now accepts --pid or -p followed by a process id.
2883 * Change in command line behavior -- corefiles vs. process ids.
2885 There is a subtle behavior in the way in which GDB handles
2886 command line arguments. The first non-flag argument is always
2887 a program to debug, but the second non-flag argument may either
2888 be a corefile or a process id. Previously, GDB would attempt to
2889 open the second argument as a corefile, and if that failed, would
2890 issue a superfluous error message and then attempt to attach it as
2891 a process. Now, if the second argument begins with a non-digit,
2892 it will be treated as a corefile. If it begins with a digit,
2893 GDB will attempt to attach it as a process, and if no such process
2894 is found, will then attempt to open it as a corefile.
2896 * Changes in ARM configurations.
2898 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2899 configuration is fully multi-arch.
2901 * New native configurations
2903 ARM NetBSD arm*-*-netbsd*
2904 x86 OpenBSD i[3456]86-*-openbsd*
2905 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2906 Sparc64 running FreeBSD sparc64-*-freebsd*
2910 Sanyo XStormy16 xstormy16-elf
2912 * OBSOLETE configurations and files
2914 Configurations that have been declared obsolete in this release have
2915 been commented out. Unless there is activity to revive these
2916 configurations, the next release of GDB will have their sources
2917 permanently REMOVED.
2919 AMD 29k family via UDI a29k-amd-udi, udi29k
2920 A29K VxWorks a29k-*-vxworks
2921 AMD 29000 embedded, using EBMON a29k-none-none
2922 AMD 29000 embedded with COFF a29k-none-coff
2923 AMD 29000 embedded with a.out a29k-none-aout
2925 testsuite/gdb.hp/gdb.threads-hp/ directory
2927 * REMOVED configurations and files
2929 TI TMS320C80 tic80-*-*
2931 PowerPC Solaris powerpcle-*-solaris*
2932 PowerPC Windows NT powerpcle-*-cygwin32
2933 PowerPC Netware powerpc-*-netware*
2934 Harris/CXUX m88k m88*-harris-cxux*
2935 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2936 ns32k-utek-sysv* ns32k-utek-*
2937 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2938 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2939 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2940 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2941 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2943 * Changes to command line processing
2945 The new `--args' feature can be used to specify command-line arguments
2946 for the inferior from gdb's command line.
2948 * Changes to key bindings
2950 There is a new `operate-and-get-next' function bound to `C-o'.
2952 *** Changes in GDB 5.1.1
2954 Fix compile problem on DJGPP.
2956 Fix a problem with floating-point registers on the i386 being
2959 Fix to stop GDB crashing on .debug_str debug info.
2961 Numerous documentation fixes.
2963 Numerous testsuite fixes.
2965 *** Changes in GDB 5.1:
2967 * New native configurations
2969 Alpha FreeBSD alpha*-*-freebsd*
2970 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2971 MIPS GNU/Linux mips*-*-linux*
2972 MIPS SGI Irix 6.x mips*-sgi-irix6*
2973 ia64 AIX ia64-*-aix*
2974 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2978 Motorola 68HC11 and 68HC12 m68hc11-elf
2980 UltraSparc running GNU/Linux sparc64-*-linux*
2982 * OBSOLETE configurations and files
2984 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2985 Harris/CXUX m88k m88*-harris-cxux*
2986 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2987 ns32k-utek-sysv* ns32k-utek-*
2988 TI TMS320C80 tic80-*-*
2990 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2991 PowerPC Solaris powerpcle-*-solaris*
2992 PowerPC Windows NT powerpcle-*-cygwin32
2993 PowerPC Netware powerpc-*-netware*
2994 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2995 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2996 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2997 Apple Macintosh (MPW) host N/A
2999 stuff.c (Program to stuff files into a specially prepared space in kdb)
3000 kdb-start.c (Main loop for the standalone kernel debugger)
3002 Configurations that have been declared obsolete in this release have
3003 been commented out. Unless there is activity to revive these
3004 configurations, the next release of GDB will have their sources
3005 permanently REMOVED.
3007 * REMOVED configurations and files
3009 Altos 3068 m68*-altos-*
3010 Convex c1-*-*, c2-*-*
3012 ARM RISCix arm-*-* (as host)
3016 * GDB has been converted to ISO C.
3018 GDB's source code has been converted to ISO C. In particular, the
3019 sources are fully protoized, and rely on standard headers being
3024 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3026 * The MI enabled by default.
3028 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3029 revised and enabled by default. Packages which use GDB as a debugging
3030 engine behind a UI or another front end are encouraged to switch to
3031 using the GDB/MI interface, instead of the old annotations interface
3032 which is now deprecated.
3034 * Support for debugging Pascal programs.
3036 GDB now includes support for debugging Pascal programs. The following
3037 main features are supported:
3039 - Pascal-specific data types such as sets;
3041 - automatic recognition of Pascal sources based on file-name
3044 - Pascal-style display of data types, variables, and functions;
3046 - a Pascal expression parser.
3048 However, some important features are not yet supported.
3050 - Pascal string operations are not supported at all;
3052 - there are some problems with boolean types;
3054 - Pascal type hexadecimal constants are not supported
3055 because they conflict with the internal variables format;
3057 - support for Pascal objects and classes is not full yet;
3059 - unlike Pascal, GDB is case-sensitive for symbol names.
3061 * Changes in completion.
3063 Commands such as `shell', `run' and `set args', which pass arguments
3064 to inferior programs, now complete on file names, similar to what
3065 users expect at the shell prompt.
3067 Commands which accept locations, such as `disassemble', `print',
3068 `breakpoint', `until', etc. now complete on filenames as well as
3069 program symbols. Thus, if you type "break foob TAB", and the source
3070 files linked into the programs include `foobar.c', that file name will
3071 be one of the candidates for completion. However, file names are not
3072 considered for completion after you typed a colon that delimits a file
3073 name from a name of a function in that file, as in "break foo.c:bar".
3075 `set demangle-style' completes on available demangling styles.
3077 * New platform-independent commands:
3079 It is now possible to define a post-hook for a command as well as a
3080 hook that runs before the command. For more details, see the
3081 documentation of `hookpost' in the GDB manual.
3083 * Changes in GNU/Linux native debugging.
3085 Support for debugging multi-threaded programs has been completely
3086 revised for all platforms except m68k and sparc. You can now debug as
3087 many threads as your system allows you to have.
3089 Attach/detach is supported for multi-threaded programs.
3091 Support for SSE registers was added for x86. This doesn't work for
3092 multi-threaded programs though.
3094 * Changes in MIPS configurations.
3096 Multi-arch support is enabled for all MIPS configurations.
3098 GDB can now be built as native debugger on SGI Irix 6.x systems for
3099 debugging n32 executables. (Debugging 64-bit executables is not yet
3102 * Unified support for hardware watchpoints in all x86 configurations.
3104 Most (if not all) native x86 configurations support hardware-assisted
3105 breakpoints and watchpoints in a unified manner. This support
3106 implements debug register sharing between watchpoints, which allows to
3107 put a virtually infinite number of watchpoints on the same address,
3108 and also supports watching regions up to 16 bytes with several debug
3111 The new maintenance command `maintenance show-debug-regs' toggles
3112 debugging print-outs in functions that insert, remove, and test
3113 watchpoints and hardware breakpoints.
3115 * Changes in the DJGPP native configuration.
3117 New command ``info dos sysinfo'' displays assorted information about
3118 the CPU, OS, memory, and DPMI server.
3120 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3121 display information about segment descriptors stored in GDT, LDT, and
3124 New commands ``info dos pde'' and ``info dos pte'' display entries
3125 from Page Directory and Page Tables (for now works with CWSDPMI only).
3126 New command ``info dos address-pte'' displays the Page Table entry for
3127 a given linear address.
3129 GDB can now pass command lines longer than 126 characters to the
3130 program being debugged (requires an update to the libdbg.a library
3131 which is part of the DJGPP development kit).
3133 DWARF2 debug info is now supported.
3135 It is now possible to `step' and `next' through calls to `longjmp'.
3137 * Changes in documentation.
3139 All GDB documentation was converted to GFDL, the GNU Free
3140 Documentation License.
3142 Tracepoints-related commands are now fully documented in the GDB
3145 TUI, the Text-mode User Interface, is now documented in the manual.
3147 Tracepoints-related commands are now fully documented in the GDB
3150 The "GDB Internals" manual now has an index. It also includes
3151 documentation of `ui_out' functions, GDB coding standards, x86
3152 hardware watchpoints, and memory region attributes.
3154 * GDB's version number moved to ``version.in''
3156 The Makefile variable VERSION has been replaced by the file
3157 ``version.in''. People creating GDB distributions should update the
3158 contents of this file.
3162 GUD support is now a standard part of the EMACS distribution.
3164 *** Changes in GDB 5.0:
3166 * Improved support for debugging FP programs on x86 targets
3168 Unified and much-improved support for debugging floating-point
3169 programs on all x86 targets. In particular, ``info float'' now
3170 displays the FP registers in the same format on all x86 targets, with
3171 greater level of detail.
3173 * Improvements and bugfixes in hardware-assisted watchpoints
3175 It is now possible to watch array elements, struct members, and
3176 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3177 on x86 targets no longer erroneously trigger when the address is
3180 * Improvements in the native DJGPP version of GDB
3182 The distribution now includes all the scripts and auxiliary files
3183 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3184 machines ``out of the box''.
3186 The DJGPP version can now debug programs that use signals. It is
3187 possible to catch signals that happened in the debuggee, deliver
3188 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3189 would kill the program being debugged.) Programs that hook hardware
3190 interrupts (keyboard, timer, etc.) can also be debugged.
3192 It is now possible to debug DJGPP programs that redirect their
3193 standard handles or switch them to raw (as opposed to cooked) mode, or
3194 even close them. The command ``run < foo > bar'' works as expected,
3195 and ``info terminal'' reports useful information about the debuggee's
3196 terminal, including raw/cooked mode, redirection, etc.
3198 The DJGPP version now uses termios functions for console I/O, which
3199 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3202 DOS-style file names with drive letters are now fully supported by
3205 It is now possible to debug DJGPP programs that switch their working
3206 directory. It is also possible to rerun the debuggee any number of
3207 times without restarting GDB; thus, you can use the same setup,
3208 breakpoints, etc. for many debugging sessions.
3210 * New native configurations
3212 ARM GNU/Linux arm*-*-linux*
3213 PowerPC GNU/Linux powerpc-*-linux*
3217 Motorola MCore mcore-*-*
3218 x86 VxWorks i[3456]86-*-vxworks*
3219 PowerPC VxWorks powerpc-*-vxworks*
3220 TI TMS320C80 tic80-*-*
3222 * OBSOLETE configurations
3224 Altos 3068 m68*-altos-*
3225 Convex c1-*-*, c2-*-*
3227 ARM RISCix arm-*-* (as host)
3230 Configurations that have been declared obsolete will be commented out,
3231 but the code will be left in place. If there is no activity to revive
3232 these configurations before the next release of GDB, the sources will
3233 be permanently REMOVED.
3235 * Gould support removed
3237 Support for the Gould PowerNode and NP1 has been removed.
3239 * New features for SVR4
3241 On SVR4 native platforms (such as Solaris), if you attach to a process
3242 without first loading a symbol file, GDB will now attempt to locate and
3243 load symbols from the running process's executable file.
3245 * Many C++ enhancements
3247 C++ support has been greatly improved. Overload resolution now works properly
3248 in almost all cases. RTTI support is on the way.
3250 * Remote targets can connect to a sub-program
3252 A popen(3) style serial-device has been added. This device starts a
3253 sub-process (such as a stand-alone simulator) and then communicates
3254 with that. The sub-program to run is specified using the syntax
3255 ``|<program> <args>'' vis:
3257 (gdb) set remotedebug 1
3258 (gdb) target extended-remote |mn10300-elf-sim program-args
3260 * MIPS 64 remote protocol
3262 A long standing bug in the mips64 remote protocol where by GDB
3263 expected certain 32 bit registers (ex SR) to be transfered as 32
3264 instead of 64 bits has been fixed.
3266 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3267 added to provide backward compatibility with older versions of GDB.
3269 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3271 The command ``set remotebinarydownload'' command has been replaced by
3272 ``set remote X-packet''. Other commands in ``set remote'' family
3273 include ``set remote P-packet''.
3275 * Breakpoint commands accept ranges.
3277 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3278 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3279 ``tracepoint passcount'' also accepts a range of tracepoints.
3281 * ``apropos'' command added.
3283 The ``apropos'' command searches through command names and
3284 documentation strings, printing out matches, making it much easier to
3285 try to find a command that does what you are looking for.
3289 A new machine oriented interface (MI) has been added to GDB. This
3290 interface is designed for debug environments running GDB as a separate
3291 process. This is part of the long term libGDB project. See the
3292 "GDB/MI" chapter of the GDB manual for further information. It can be
3293 enabled by configuring with:
3295 .../configure --enable-gdbmi
3297 *** Changes in GDB-4.18:
3299 * New native configurations
3301 HP-UX 10.20 hppa*-*-hpux10.20
3302 HP-UX 11.x hppa*-*-hpux11.0*
3303 M68K GNU/Linux m68*-*-linux*
3307 Fujitsu FR30 fr30-*-elf*
3308 Intel StrongARM strongarm-*-*
3309 Mitsubishi D30V d30v-*-*
3311 * OBSOLETE configurations
3313 Gould PowerNode, NP1 np1-*-*, pn-*-*
3315 Configurations that have been declared obsolete will be commented out,
3316 but the code will be left in place. If there is no activity to revive
3317 these configurations before the next release of GDB, the sources will
3318 be permanently REMOVED.
3322 As a compatibility experiment, GDB's source files buildsym.h and
3323 buildsym.c have been converted to pure standard C, no longer
3324 containing any K&R compatibility code. We believe that all systems in
3325 use today either come with a standard C compiler, or have a GCC port
3326 available. If this is not true, please report the affected
3327 configuration to bug-gdb@gnu.org immediately. See the README file for
3328 information about getting a standard C compiler if you don't have one
3333 GDB now uses readline 2.2.
3335 * set extension-language
3337 You can now control the mapping between filename extensions and source
3338 languages by using the `set extension-language' command. For instance,
3339 you can ask GDB to treat .c files as C++ by saying
3340 set extension-language .c c++
3341 The command `info extensions' lists all of the recognized extensions
3342 and their associated languages.
3344 * Setting processor type for PowerPC and RS/6000
3346 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3347 you can use the `set processor' command to specify what variant of the
3348 PowerPC family you are debugging. The command
3352 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3353 following PowerPC and RS6000 variants:
3355 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3356 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3358 403GC IBM PowerPC 403GC
3359 505 Motorola PowerPC 505
3360 860 Motorola PowerPC 860 or 850
3361 601 Motorola PowerPC 601
3362 602 Motorola PowerPC 602
3363 603 Motorola/IBM PowerPC 603 or 603e
3364 604 Motorola PowerPC 604 or 604e
3365 750 Motorola/IBM PowerPC 750 or 750
3367 At the moment, this command just tells GDB what to name the
3368 special-purpose processor registers. Since almost all the affected
3369 registers are inaccessible to user-level programs, this command is
3370 only useful for remote debugging in its present form.
3374 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3375 more extensive support for HP-UX. Added features include shared
3376 library support, kernel threads and hardware watchpoints for 11.00,
3377 support for HP's ANSI C and C++ compilers, and a compatibility mode
3378 for xdb and dbx commands.
3382 HP's donation includes the new concept of catchpoints, which is a
3383 generalization of the old catch command. On HP-UX, it is now possible
3384 to catch exec, fork, and vfork, as well as library loading.
3386 This means that the existing catch command has changed; its first
3387 argument now specifies the type of catch to be set up. See the
3388 output of "help catch" for a list of catchpoint types.
3390 * Debugging across forks
3392 On HP-UX, you can choose which process to debug when a fork() happens
3397 HP has donated a curses-based terminal user interface (TUI). To get
3398 it, build with --enable-tui. Although this can be enabled for any
3399 configuration, at present it only works for native HP debugging.
3401 * GDB remote protocol additions
3403 A new protocol packet 'X' that writes binary data is now available.
3404 Default behavior is to try 'X', then drop back to 'M' if the stub
3405 fails to respond. The settable variable `remotebinarydownload'
3406 allows explicit control over the use of 'X'.
3408 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3409 full 64-bit address. The command
3411 set remoteaddresssize 32
3413 can be used to revert to the old behaviour. For existing remote stubs
3414 the change should not be noticed, as the additional address information
3417 In order to assist in debugging stubs, you may use the maintenance
3418 command `packet' to send any text string to the stub. For instance,
3420 maint packet heythere
3422 sends the packet "$heythere#<checksum>". Note that it is very easy to
3423 disrupt a debugging session by sending the wrong packet at the wrong
3426 The compare-sections command allows you to compare section data on the
3427 target to what is in the executable file without uploading or
3428 downloading, by comparing CRC checksums.
3430 * Tracing can collect general expressions
3432 You may now collect general expressions at tracepoints. This requires
3433 further additions to the target-side stub; see tracepoint.c and
3434 doc/agentexpr.texi for further details.
3436 * mask-address variable for Mips
3438 For Mips targets, you may control the zeroing of the upper 32 bits of
3439 a 64-bit address by entering `set mask-address on'. This is mainly
3440 of interest to users of embedded R4xxx and R5xxx processors.
3442 * Higher serial baud rates
3444 GDB's serial code now allows you to specify baud rates 57600, 115200,
3445 230400, and 460800 baud. (Note that your host system may not be able
3446 to achieve all of these rates.)
3450 The i960 configuration now includes an initial implementation of a
3451 builtin simulator, contributed by Jim Wilson.
3454 *** Changes in GDB-4.17:
3456 * New native configurations
3458 Alpha GNU/Linux alpha*-*-linux*
3459 Unixware 2.x i[3456]86-unixware2*
3460 Irix 6.x mips*-sgi-irix6*
3461 PowerPC GNU/Linux powerpc-*-linux*
3462 PowerPC Solaris powerpcle-*-solaris*
3463 Sparc GNU/Linux sparc-*-linux*
3464 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3468 Argonaut Risc Chip (ARC) arc-*-*
3469 Hitachi H8/300S h8300*-*-*
3470 Matsushita MN10200 w/simulator mn10200-*-*
3471 Matsushita MN10300 w/simulator mn10300-*-*
3472 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3473 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3474 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3475 Mitsubishi D10V w/simulator d10v-*-*
3476 Mitsubishi M32R/D w/simulator m32r-*-elf*
3477 Tsqware Sparclet sparclet-*-*
3478 NEC V850 w/simulator v850-*-*
3480 * New debugging protocols
3482 ARM with RDI protocol arm*-*-*
3483 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3484 DDB and LSI variants of PMON protocol mips*-*-*
3485 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3486 PowerPC with SDS protocol powerpc{,le}-*-eabi
3487 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3491 All configurations can now understand and use the DWARF 2 debugging
3492 format. The choice is automatic, if the symbol file contains DWARF 2
3497 GDB now includes basic Java language support. This support is
3498 only useful with Java compilers that produce native machine code.
3500 * solib-absolute-prefix and solib-search-path
3502 For SunOS and SVR4 shared libraries, you may now set the prefix for
3503 loading absolute shared library symbol files, and the search path for
3504 locating non-absolute shared library symbol files.
3506 * Live range splitting
3508 GDB can now effectively debug code for which GCC has performed live
3509 range splitting as part of its optimization. See gdb/doc/LRS for
3510 more details on the expected format of the stabs information.
3514 GDB's support for the GNU Hurd, including thread debugging, has been
3515 updated to work with current versions of the Hurd.
3519 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3520 instruction set. ARM GDB automatically detects when Thumb
3521 instructions are in use, and adjusts disassembly and backtracing
3526 GDB's MIPS target configurations now handle the MIP16 16-bit
3531 GDB now includes support for overlays; if an executable has been
3532 linked such that multiple sections are based at the same address, GDB
3533 will decide which section to use for symbolic info. You can choose to
3534 control the decision manually, using overlay commands, or implement
3535 additional target-side support and use "overlay load-target" to bring
3536 in the overlay mapping. Do "help overlay" for more detail.
3540 The command "info symbol <address>" displays information about
3541 the symbol at the specified address.
3545 The standard remote protocol now includes an extension that allows
3546 asynchronous collection and display of trace data. This requires
3547 extensive support in the target-side debugging stub. Tracing mode
3548 includes a new interaction mode in GDB and new commands: see the
3549 file tracepoint.c for more details.
3553 Configurations for embedded MIPS now include a simulator contributed
3554 by Cygnus Solutions. The simulator supports the instruction sets
3555 of most MIPS variants.
3559 Sparc configurations may now include the ERC32 simulator contributed
3560 by the European Space Agency. The simulator is not built into
3561 Sparc targets by default; configure with --enable-sim to include it.
3565 For target configurations that may include multiple variants of a
3566 basic architecture (such as MIPS and SH), you may now set the
3567 architecture explicitly. "set arch" sets, "info arch" lists
3568 the possible architectures.
3570 *** Changes in GDB-4.16:
3572 * New native configurations
3574 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3575 M68K NetBSD m68k-*-netbsd*
3576 PowerPC AIX 4.x powerpc-*-aix*
3577 PowerPC MacOS powerpc-*-macos*
3578 PowerPC Windows NT powerpcle-*-cygwin32
3579 RS/6000 AIX 4.x rs6000-*-aix4*
3583 ARM with RDP protocol arm-*-*
3584 I960 with MON960 i960-*-coff
3585 MIPS VxWorks mips*-*-vxworks*
3586 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3587 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3589 Matra Sparclet sparclet-*-*
3593 The powerpc-eabi configuration now includes the PSIM simulator,
3594 contributed by Andrew Cagney, with assistance from Mike Meissner.
3595 PSIM is a very elaborate model of the PowerPC, including not only
3596 basic instruction set execution, but also details of execution unit
3597 performance and I/O hardware. See sim/ppc/README for more details.
3601 GDB now works with Solaris 2.5.
3603 * Windows 95/NT native
3605 GDB will now work as a native debugger on Windows 95 and Windows NT.
3606 To build it from source, you must use the "gnu-win32" environment,
3607 which uses a DLL to emulate enough of Unix to run the GNU tools.
3608 Further information, binaries, and sources are available at
3609 ftp.cygnus.com, under pub/gnu-win32.
3611 * dont-repeat command
3613 If a user-defined command includes the command `dont-repeat', then the
3614 command will not be repeated if the user just types return. This is
3615 useful if the command is time-consuming to run, so that accidental
3616 extra keystrokes don't run the same command many times.
3618 * Send break instead of ^C
3620 The standard remote protocol now includes an option to send a break
3621 rather than a ^C to the target in order to interrupt it. By default,
3622 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3624 * Remote protocol timeout
3626 The standard remote protocol includes a new variable `remotetimeout'
3627 that allows you to set the number of seconds before GDB gives up trying
3628 to read from the target. The default value is 2.
3630 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3632 By default GDB will automatically keep track of objects as they are
3633 loaded and unloaded by the dynamic linker. By using the command `set
3634 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3635 when shared library events occur, thus allowing you to set breakpoints
3636 in shared libraries which are explicitly loaded by the inferior.
3638 Note this feature does not work on hpux8. On hpux9 you must link
3639 /usr/lib/end.o into your program. This feature should work
3640 automatically on hpux10.
3642 * Irix 5.x hardware watchpoint support
3644 Irix 5 configurations now support the use of hardware watchpoints.
3646 * Mips protocol "SYN garbage limit"
3648 When debugging a Mips target using the `target mips' protocol, you
3649 may set the number of characters that GDB will ignore by setting
3650 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3651 every character. The default value is 1050.
3653 * Recording and replaying remote debug sessions
3655 If you set `remotelogfile' to the name of a file, gdb will write to it
3656 a recording of a remote debug session. This recording may then be
3657 replayed back to gdb using "gdbreplay". See gdbserver/README for
3658 details. This is useful when you have a problem with GDB while doing
3659 remote debugging; you can make a recording of the session and send it
3660 to someone else, who can then recreate the problem.
3662 * Speedups for remote debugging
3664 GDB includes speedups for downloading and stepping MIPS systems using
3665 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3666 and more efficient S-record downloading.
3668 * Memory use reductions and statistics collection
3670 GDB now uses less memory and reports statistics about memory usage.
3671 Try the `maint print statistics' command, for example.
3673 *** Changes in GDB-4.15:
3675 * Psymtabs for XCOFF
3677 The symbol reader for AIX GDB now uses partial symbol tables. This
3678 can greatly improve startup time, especially for large executables.
3680 * Remote targets use caching
3682 Remote targets now use a data cache to speed up communication with the
3683 remote side. The data cache could lead to incorrect results because
3684 it doesn't know about volatile variables, thus making it impossible to
3685 debug targets which use memory mapped I/O devices. `set remotecache
3686 off' turns the the data cache off.
3688 * Remote targets may have threads
3690 The standard remote protocol now includes support for multiple threads
3691 in the target system, using new protocol commands 'H' and 'T'. See
3692 gdb/remote.c for details.
3696 If GDB is configured with `--enable-netrom', then it will include
3697 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3698 acts as though it is a bank of ROM on the target board, but you can
3699 write into it over the network. GDB's support consists only of
3700 support for fast loading into the emulated ROM; to debug, you must use
3701 another protocol, such as standard remote protocol. The usual
3702 sequence is something like
3704 target nrom <netrom-hostname>
3706 target remote <netrom-hostname>:1235
3710 GDB now includes support for the Apple Macintosh, as a host only. It
3711 may be run as either an MPW tool or as a standalone application, and
3712 it can debug through the serial port. All the usual GDB commands are
3713 available, but to the target command, you must supply "serial" as the
3714 device type instead of "/dev/ttyXX". See mpw-README in the main
3715 directory for more information on how to build. The MPW configuration
3716 scripts */mpw-config.in support only a few targets, and only the
3717 mips-idt-ecoff target has been tested.
3721 GDB configuration now uses autoconf. This is not user-visible,
3722 but does simplify configuration and building.
3726 GDB now supports hpux10.
3728 *** Changes in GDB-4.14:
3730 * New native configurations
3732 x86 FreeBSD i[345]86-*-freebsd
3733 x86 NetBSD i[345]86-*-netbsd
3734 NS32k NetBSD ns32k-*-netbsd
3735 Sparc NetBSD sparc-*-netbsd
3739 A29K VxWorks a29k-*-vxworks
3740 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3741 CPU32 EST-300 emulator m68*-*-est*
3742 PowerPC ELF powerpc-*-elf
3745 * Alpha OSF/1 support for procfs
3747 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3748 possible to attach to running processes. As the mounting of the /proc
3749 filesystem is optional on the Alpha, GDB automatically determines
3750 the availability of /proc during startup. This can lead to problems
3751 if /proc is unmounted after GDB has been started.
3753 * Arguments to user-defined commands
3755 User commands may accept up to 10 arguments separated by whitespace.
3756 Arguments are accessed within the user command via $arg0..$arg9. A
3759 print $arg0 + $arg1 + $arg2
3761 To execute the command use:
3764 Defines the command "adder" which prints the sum of its three arguments.
3765 Note the arguments are text substitutions, so they may reference variables,
3766 use complex expressions, or even perform inferior function calls.
3768 * New `if' and `while' commands
3770 This makes it possible to write more sophisticated user-defined
3771 commands. Both commands take a single argument, which is the
3772 expression to evaluate, and must be followed by the commands to
3773 execute, one per line, if the expression is nonzero, the list being
3774 terminated by the word `end'. The `if' command list may include an
3775 `else' word, which causes the following commands to be executed only
3776 if the expression is zero.
3778 * Fortran source language mode
3780 GDB now includes partial support for Fortran 77. It will recognize
3781 Fortran programs and can evaluate a subset of Fortran expressions, but
3782 variables and functions may not be handled correctly. GDB will work
3783 with G77, but does not yet know much about symbols emitted by other
3786 * Better HPUX support
3788 Most debugging facilities now work on dynamic executables for HPPAs
3789 running hpux9 or later. You can attach to running dynamically linked
3790 processes, but by default the dynamic libraries will be read-only, so
3791 for instance you won't be able to put breakpoints in them. To change
3792 that behavior do the following before running the program:
3798 This will cause the libraries to be mapped private and read-write.
3799 To revert to the normal behavior, do this:
3805 You cannot set breakpoints or examine data in the library until after
3806 the library is loaded if the function/data symbols do not have
3809 GDB can now also read debug symbols produced by the HP C compiler on
3810 HPPAs (sorry, no C++, Fortran or 68k support).
3812 * Target byte order now dynamically selectable
3814 You can choose which byte order to use with a target system, via the
3815 commands "set endian big" and "set endian little", and you can see the
3816 current setting by using "show endian". You can also give the command
3817 "set endian auto", in which case GDB will use the byte order
3818 associated with the executable. Currently, only embedded MIPS
3819 configurations support dynamic selection of target byte order.
3821 * New DOS host serial code
3823 This version uses DPMI interrupts to handle buffered I/O, so you
3824 no longer need to run asynctsr when debugging boards connected to
3827 *** Changes in GDB-4.13:
3829 * New "complete" command
3831 This lists all the possible completions for the rest of the line, if it
3832 were to be given as a command itself. This is intended for use by emacs.
3834 * Trailing space optional in prompt
3836 "set prompt" no longer adds a space for you after the prompt you set. This
3837 allows you to set a prompt which ends in a space or one that does not.
3839 * Breakpoint hit counts
3841 "info break" now displays a count of the number of times the breakpoint
3842 has been hit. This is especially useful in conjunction with "ignore"; you
3843 can ignore a large number of breakpoint hits, look at the breakpoint info
3844 to see how many times the breakpoint was hit, then run again, ignoring one
3845 less than that number, and this will get you quickly to the last hit of
3848 * Ability to stop printing at NULL character
3850 "set print null-stop" will cause GDB to stop printing the characters of
3851 an array when the first NULL is encountered. This is useful when large
3852 arrays actually contain only short strings.
3854 * Shared library breakpoints
3856 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3857 breakpoints in shared libraries before the executable is run.
3859 * Hardware watchpoints
3861 There is a new hardware breakpoint for the watch command for sparclite
3862 targets. See gdb/sparclite/hw_breakpoint.note.
3864 Hardware watchpoints are also now supported under GNU/Linux.
3868 Annotations have been added. These are for use with graphical interfaces,
3869 and are still experimental. Currently only gdba.el uses these.
3871 * Improved Irix 5 support
3873 GDB now works properly with Irix 5.2.
3875 * Improved HPPA support
3877 GDB now works properly with the latest GCC and GAS.
3879 * New native configurations
3881 Sequent PTX4 i[34]86-sequent-ptx4
3882 HPPA running OSF/1 hppa*-*-osf*
3883 Atari TT running SVR4 m68*-*-sysv4*
3884 RS/6000 LynxOS rs6000-*-lynxos*
3888 OS/9000 i[34]86-*-os9k
3889 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3892 * Hitachi SH7000 and E7000-PC ICE support
3894 There is now support for communicating with the Hitachi E7000-PC ICE.
3895 This is available automatically when GDB is configured for the SH.
3899 As usual, a variety of small fixes and improvements, both generic
3900 and configuration-specific. See the ChangeLog for more detail.
3902 *** Changes in GDB-4.12:
3904 * Irix 5 is now supported
3908 GDB-4.12 on the HPPA has a number of changes which make it unable
3909 to debug the output from the currently released versions of GCC and
3910 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3911 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3912 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3915 *** Changes in GDB-4.11:
3917 * User visible changes:
3921 The "set remotedebug" option is now consistent between the mips remote
3922 target, remote targets using the gdb-specific protocol, UDI (AMD's
3923 debug protocol for the 29k) and the 88k bug monitor. It is now an
3924 integer specifying a debug level (normally 0 or 1, but 2 means more
3925 debugging info for the mips target).
3927 * DEC Alpha native support
3929 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3930 debug info, but GDB works fairly well with the DEC compiler and should
3931 work with a future GCC release. See the README file for a few
3932 Alpha-specific notes.
3934 * Preliminary thread implementation
3936 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3938 * LynxOS native and target support for 386
3940 This release has been hosted on LynxOS 2.2, and also can be configured
3941 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3944 * Improvements in C++ mangling/demangling.
3946 This release has much better g++ debugging, specifically in name
3947 mangling/demangling, virtual function calls, print virtual table,
3948 call methods, ...etc.
3950 *** Changes in GDB-4.10:
3952 * User visible changes:
3954 Remote debugging using the GDB-specific (`target remote') protocol now
3955 supports the `load' command. This is only useful if you have some
3956 other way of getting the stub to the target system, and you can put it
3957 somewhere in memory where it won't get clobbered by the download.
3959 Filename completion now works.
3961 When run under emacs mode, the "info line" command now causes the
3962 arrow to point to the line specified. Also, "info line" prints
3963 addresses in symbolic form (as well as hex).
3965 All vxworks based targets now support a user settable option, called
3966 vxworks-timeout. This option represents the number of seconds gdb
3967 should wait for responses to rpc's. You might want to use this if
3968 your vxworks target is, perhaps, a slow software simulator or happens
3969 to be on the far side of a thin network line.
3973 This release contains support for using a DEC alpha as a GDB host for
3974 cross debugging. Native alpha debugging is not supported yet.
3977 *** Changes in GDB-4.9:
3981 This is the first GDB release which is accompanied by a matching testsuite.
3982 The testsuite requires installation of dejagnu, which should be available
3983 via ftp from most sites that carry GNU software.
3987 'Cfront' style demangling has had its name changed to 'ARM' style, to
3988 emphasize that it was written from the specifications in the C++ Annotated
3989 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3990 disclaimers, it still generated too much confusion with users attempting to
3991 use gdb with AT&T cfront.
3995 GDB now uses a standard remote interface to a simulator library.
3996 So far, the library contains simulators for the Zilog Z8001/2, the
3997 Hitachi H8/300, H8/500 and Super-H.
3999 * New targets supported
4001 H8/300 simulator h8300-hitachi-hms or h8300hms
4002 H8/500 simulator h8500-hitachi-hms or h8500hms
4003 SH simulator sh-hitachi-hms or sh
4004 Z8000 simulator z8k-zilog-none or z8ksim
4005 IDT MIPS board over serial line mips-idt-ecoff
4007 Cross-debugging to GO32 targets is supported. It requires a custom
4008 version of the i386-stub.c module which is integrated with the
4009 GO32 memory extender.
4011 * New remote protocols
4013 MIPS remote debugging protocol.
4015 * New source languages supported
4017 This version includes preliminary support for Chill, a Pascal like language
4018 used by telecommunications companies. Chill support is also being integrated
4019 into the GNU compiler, but we don't know when it will be publically available.
4022 *** Changes in GDB-4.8:
4024 * HP Precision Architecture supported
4026 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4027 version of this support was available as a set of patches from the
4028 University of Utah. GDB does not support debugging of programs
4029 compiled with the HP compiler, because HP will not document their file
4030 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4031 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4033 Many problems in the preliminary version have been fixed.
4035 * Faster and better demangling
4037 We have improved template demangling and fixed numerous bugs in the GNU style
4038 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4039 character types (wchar_t) are now supported. Demangling of each symbol is now
4040 only done once, and is cached when the symbol table for a file is read in.
4041 This results in a small increase in memory usage for C programs, a moderate
4042 increase in memory usage for C++ programs, and a fantastic speedup in
4045 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4046 from the specifications in the Annotated Reference Manual, which AT&T's
4047 compiler does not actually implement.
4049 * G++ multiple inheritance compiler problem
4051 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4052 inheritance lattices was reworked to properly discover ambiguities. We
4053 recently found an example which causes this new algorithm to fail in a
4054 very subtle way, producing bad debug information for those classes.
4055 The file 'gcc.patch' (in this directory) can be applied to gcc to
4056 circumvent the problem. A future GCC release will contain a complete
4059 The previous G++ debug info problem (mentioned below for the gdb-4.7
4060 release) is fixed in gcc version 2.3.2.
4062 * Improved configure script
4064 The `configure' script will now attempt to guess your system type if
4065 you don't supply a host system type. The old scheme of supplying a
4066 host system triplet is preferable over using this. All the magic is
4067 done in the new `config.guess' script. Examine it for details.
4069 We have also brought our configure script much more in line with the FSF's
4070 version. It now supports the --with-xxx options. In particular,
4071 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4072 The resulting GDB will not be able to read arbitrary object file formats --
4073 only the format ``expected'' to be used on the configured target system.
4074 We hope to make this the default in a future release.
4076 * Documentation improvements
4078 There's new internal documentation on how to modify GDB, and how to
4079 produce clean changes to the code. We implore people to read it
4080 before submitting changes.
4082 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4083 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4084 `info' files are also provided. To build `info' files from scratch,
4085 you will need the latest `makeinfo' release, which will be available in
4086 a future texinfo-X.Y release.
4088 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4089 We're not sure exactly which versions have this problem, but it has
4090 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4091 or better. If that isn't possible, there is a patch in
4092 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4093 around this problem.
4097 GDB now supports array constants that can be used in expressions typed in by
4098 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4099 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4102 The new directory `gdb/sparclite' contains a program that demonstrates
4103 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4105 * New native hosts supported
4107 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4108 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4110 * New targets supported
4112 AMD 29k family via UDI a29k-amd-udi or udi29k
4114 * New file formats supported
4116 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4117 HPUX core files, and SCO 3.2v2 core files.
4121 Attaching to processes now works again; thanks for the many bug reports.
4123 We have also stomped on a bunch of core dumps caused by
4124 printf_filtered("%s") problems.
4126 We eliminated a copyright problem on the rpc and ptrace header files
4127 for VxWorks, which was discovered at the last minute during the 4.7
4128 release. You should now be able to build a VxWorks GDB.
4130 You can now interrupt gdb while an attached process is running. This
4131 will cause the attached process to stop, and give control back to GDB.
4133 We fixed problems caused by using too many file descriptors
4134 for reading symbols from object files and libraries. This was
4135 especially a problem for programs that used many (~100) shared
4138 The `step' command now only enters a subroutine if there is line number
4139 information for the subroutine. Otherwise it acts like the `next'
4140 command. Previously, `step' would enter subroutines if there was
4141 any debugging information about the routine. This avoids problems
4142 when using `cc -g1' on MIPS machines.
4144 * Internal improvements
4146 GDB's internal interfaces have been improved to make it easier to support
4147 debugging of multiple languages in the future.
4149 GDB now uses a common structure for symbol information internally.
4150 Minimal symbols (derived from linkage symbols in object files), partial
4151 symbols (from a quick scan of debug information), and full symbols
4152 contain a common subset of information, making it easier to write
4153 shared code that handles any of them.
4155 * New command line options
4157 We now accept --silent as an alias for --quiet.
4161 The memory-mapped-malloc library is now licensed under the GNU Library
4162 General Public License.
4164 *** Changes in GDB-4.7:
4166 * Host/native/target split
4168 GDB has had some major internal surgery to untangle the support for
4169 hosts and remote targets. Now, when you configure GDB for a remote
4170 target, it will no longer load in all of the support for debugging
4171 local programs on the host. When fully completed and tested, this will
4172 ensure that arbitrary host/target combinations are possible.
4174 The primary conceptual shift is to separate the non-portable code in
4175 GDB into three categories. Host specific code is required any time GDB
4176 is compiled on that host, regardless of the target. Target specific
4177 code relates to the peculiarities of the target, but can be compiled on
4178 any host. Native specific code is everything else: it can only be
4179 built when the host and target are the same system. Child process
4180 handling and core file support are two common `native' examples.
4182 GDB's use of /proc for controlling Unix child processes is now cleaner.
4183 It has been split out into a single module under the `target_ops' vector,
4184 plus two native-dependent functions for each system that uses /proc.
4186 * New hosts supported
4188 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4189 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4190 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4192 * New targets supported
4194 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4195 68030 and CPU32 m68030-*-*, m68332-*-*
4197 * New native hosts supported
4199 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4200 (386bsd is not well tested yet)
4201 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4203 * New file formats supported
4205 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4206 supports reading of `a.out.adobe' object files, which are an a.out
4207 format extended with minimal information about multiple sections.
4211 `show copying' is the same as the old `info copying'.
4212 `show warranty' is the same as `info warrantee'.
4213 These were renamed for consistency. The old commands continue to work.
4215 `info handle' is a new alias for `info signals'.
4217 You can now define pre-command hooks, which attach arbitrary command
4218 scripts to any command. The commands in the hook will be executed
4219 prior to the user's command. You can also create a hook which will be
4220 executed whenever the program stops. See gdb.texinfo.
4224 We now deal with Cfront style name mangling, and can even extract type
4225 info from mangled symbols. GDB can automatically figure out which
4226 symbol mangling style your C++ compiler uses.
4228 Calling of methods and virtual functions has been improved as well.
4232 The crash that occured when debugging Sun Ansi-C compiled binaries is
4233 fixed. This was due to mishandling of the extra N_SO stabs output
4236 We also finally got Ultrix 4.2 running in house, and fixed core file
4237 support, with help from a dozen people on the net.
4239 John M. Farrell discovered that the reason that single-stepping was so
4240 slow on all of the Mips based platforms (primarily SGI and DEC) was
4241 that we were trying to demangle and lookup a symbol used for internal
4242 purposes on every instruction that was being stepped through. Changing
4243 the name of that symbol so that it couldn't be mistaken for a C++
4244 mangled symbol sped things up a great deal.
4246 Rich Pixley sped up symbol lookups in general by getting much smarter
4247 about when C++ symbol mangling is necessary. This should make symbol
4248 completion (TAB on the command line) much faster. It's not as fast as
4249 we'd like, but it's significantly faster than gdb-4.6.
4253 A new user controllable variable 'call_scratch_address' can
4254 specify the location of a scratch area to be used when GDB
4255 calls a function in the target. This is necessary because the
4256 usual method of putting the scratch area on the stack does not work
4257 in systems that have separate instruction and data spaces.
4259 We integrated changes to support the 29k UDI (Universal Debugger
4260 Interface), but discovered at the last minute that we didn't have all
4261 of the appropriate copyright paperwork. We are working with AMD to
4262 resolve this, and hope to have it available soon.
4266 We have sped up the remote serial line protocol, especially for targets
4267 with lots of registers. It now supports a new `expedited status' ('T')
4268 message which can be used in place of the existing 'S' status message.
4269 This allows the remote stub to send only the registers that GDB
4270 needs to make a quick decision about single-stepping or conditional
4271 breakpoints, eliminating the need to fetch the entire register set for
4272 each instruction being stepped through.
4274 The GDB remote serial protocol now implements a write-through cache for
4275 registers, only re-reading the registers if the target has run.
4277 There is also a new remote serial stub for SPARC processors. You can
4278 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4279 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4280 processor with a serial port.
4284 Configure.in files have become much easier to read and modify. A new
4285 `table driven' format makes it more obvious what configurations are
4286 supported, and what files each one uses.
4290 There is a new opcodes library which will eventually contain all of the
4291 disassembly routines and opcode tables. At present, it only contains
4292 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4293 disassembler (binutils/objdump) to share these routines.
4295 The libiberty library is now copylefted under the GNU Library General
4296 Public License. This allows more liberal use, and was done so libg++
4297 can use it. This makes no difference to GDB, since the Library License
4298 grants all the rights from the General Public License.
4302 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4303 reference to the stabs symbol info used by the debugger. It is (as far
4304 as we know) the only published document on this fascinating topic. We
4305 encourage you to read it, compare it to the stabs information on your
4306 system, and send improvements on the document in general (to
4307 bug-gdb@prep.ai.mit.edu).
4309 And, of course, many bugs have been fixed.
4312 *** Changes in GDB-4.6:
4314 * Better support for C++ function names
4316 GDB now accepts as input the "demangled form" of C++ overloaded function
4317 names and member function names, and can do command completion on such names
4318 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4319 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4320 Make use of command completion, it is your friend.
4322 GDB also now accepts a variety of C++ mangled symbol formats. They are
4323 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4324 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4325 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4326 for the list of formats.
4328 * G++ symbol mangling problem
4330 Recent versions of gcc have a bug in how they emit debugging information for
4331 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4332 directory) can be applied to gcc to fix the problem. Alternatively, if you
4333 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4334 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4335 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4338 * New 'maintenance' command
4340 All of the commands related to hacking GDB internals have been moved out of
4341 the main command set, and now live behind the 'maintenance' command. This
4342 can also be abbreviated as 'mt'. The following changes were made:
4344 dump-me -> maintenance dump-me
4345 info all-breakpoints -> maintenance info breakpoints
4346 printmsyms -> maintenance print msyms
4347 printobjfiles -> maintenance print objfiles
4348 printpsyms -> maintenance print psymbols
4349 printsyms -> maintenance print symbols
4351 The following commands are new:
4353 maintenance demangle Call internal GDB demangler routine to
4354 demangle a C++ link name and prints the result.
4355 maintenance print type Print a type chain for a given symbol
4357 * Change to .gdbinit file processing
4359 We now read the $HOME/.gdbinit file before processing the argv arguments
4360 (e.g. reading symbol files or core files). This allows global parameters to
4361 be set, which will apply during the symbol reading. The ./.gdbinit is still
4362 read after argv processing.
4364 * New hosts supported
4366 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4368 GNU/Linux support i386-unknown-linux or linux
4370 We are also including code to support the HP/PA running BSD and HPUX. This
4371 is almost guaranteed not to work, as we didn't have time to test or build it
4372 for this release. We are including it so that the more adventurous (or
4373 masochistic) of you can play with it. We also had major problems with the
4374 fact that the compiler that we got from HP doesn't support the -g option.
4377 * New targets supported
4379 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4381 * More smarts about finding #include files
4383 GDB now remembers the compilation directory for all include files, and for
4384 all files from which C is generated (like yacc and lex sources). This
4385 greatly improves GDB's ability to find yacc/lex sources, and include files,
4386 especially if you are debugging your program from a directory different from
4387 the one that contains your sources.
4389 We also fixed a bug which caused difficulty with listing and setting
4390 breakpoints in include files which contain C code. (In the past, you had to
4391 try twice in order to list an include file that you hadn't looked at before.)
4393 * Interesting infernals change
4395 GDB now deals with arbitrary numbers of sections, where the symbols for each
4396 section must be relocated relative to that section's landing place in the
4397 target's address space. This work was needed to support ELF with embedded
4398 stabs used by Solaris-2.0.
4400 * Bug fixes (of course!)
4402 There have been loads of fixes for the following things:
4403 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4404 i960, stabs, DOS(GO32), procfs, etc...
4406 See the ChangeLog for details.
4408 *** Changes in GDB-4.5:
4410 * New machines supported (host and target)
4412 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4414 SGI Irix-4.x mips-sgi-irix4 or iris4
4416 * New malloc package
4418 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4419 Mmalloc is capable of handling mutiple heaps of memory. It is also
4420 capable of saving a heap to a file, and then mapping it back in later.
4421 This can be used to greatly speedup the startup of GDB by using a
4422 pre-parsed symbol table which lives in a mmalloc managed heap. For
4423 more details, please read mmalloc/mmalloc.texi.
4427 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4428 'help info proc' for details.
4430 * MIPS ecoff symbol table format
4432 The code that reads MIPS symbol table format is now supported on all hosts.
4433 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4436 * File name changes for MS-DOS
4438 Many files in the config directories have been renamed to make it easier to
4439 support GDB on MS-DOSe systems (which have very restrictive file name
4440 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4441 environment) is close to working but has some remaining problems. Note
4442 that debugging of DOS programs is not supported, due to limitations
4443 in the ``operating system'', but it can be used to host cross-debugging.
4445 * Cross byte order fixes
4447 Many fixes have been made to support cross debugging of Sparc and MIPS
4448 targets from hosts whose byte order differs.
4450 * New -mapped and -readnow options
4452 If memory-mapped files are available on your system through the 'mmap'
4453 system call, you can use the -mapped option on the `file' or
4454 `symbol-file' commands to cause GDB to write the symbols from your
4455 program into a reusable file. If the program you are debugging is
4456 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4457 Future GDB debugging sessions will notice the presence of this file,
4458 and will quickly map in symbol information from it, rather than reading
4459 the symbol table from the executable program. Using the '-mapped'
4460 option in a GDB `file' or `symbol-file' command has the same effect as
4461 starting GDB with the '-mapped' command-line option.
4463 You can cause GDB to read the entire symbol table immediately by using
4464 the '-readnow' option with any of the commands that load symbol table
4465 information (or on the GDB command line). This makes the command
4466 slower, but makes future operations faster.
4468 The -mapped and -readnow options are typically combined in order to
4469 build a `fred.syms' file that contains complete symbol information.
4470 A simple GDB invocation to do nothing but build a `.syms' file for future
4473 gdb -batch -nx -mapped -readnow programname
4475 The `.syms' file is specific to the host machine on which GDB is run.
4476 It holds an exact image of GDB's internal symbol table. It cannot be
4477 shared across multiple host platforms.
4479 * longjmp() handling
4481 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4482 siglongjmp() without losing control. This feature has not yet been ported to
4483 all systems. It currently works on many 386 platforms, all MIPS-based
4484 platforms (SGI, DECstation, etc), and Sun3/4.
4488 Preliminary work has been put in to support the new Solaris OS from Sun. At
4489 this time, it can control and debug processes, but it is not capable of
4494 As always, many many bug fixes. The major areas were with g++, and mipsread.
4495 People using the MIPS-based platforms should experience fewer mysterious
4496 crashes and trashed symbol tables.
4498 *** Changes in GDB-4.4:
4500 * New machines supported (host and target)
4502 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4504 BSD Reno on Vax vax-dec-bsd
4505 Ultrix on Vax vax-dec-ultrix
4507 * New machines supported (target)
4509 AMD 29000 embedded, using EBMON a29k-none-none
4513 GDB continues to improve its handling of C++. `References' work better.
4514 The demangler has also been improved, and now deals with symbols mangled as
4515 per the Annotated C++ Reference Guide.
4517 GDB also now handles `stabs' symbol information embedded in MIPS
4518 `ecoff' symbol tables. Since the ecoff format was not easily
4519 extensible to handle new languages such as C++, this appeared to be a
4520 good way to put C++ debugging info into MIPS binaries. This option
4521 will be supported in the GNU C compiler, version 2, when it is
4524 * New features for SVR4
4526 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4527 shared libraries. Debugging dynamically linked programs should present
4528 only minor differences from debugging statically linked programs.
4530 The `info proc' command will print out information about any process
4531 on an SVR4 system (including the one you are debugging). At the moment,
4532 it prints the address mappings of the process.
4534 If you bring up GDB on another SVR4 system, please send mail to
4535 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4537 * Better dynamic linking support in SunOS
4539 Reading symbols from shared libraries which contain debugging symbols
4540 now works properly. However, there remain issues such as automatic
4541 skipping of `transfer vector' code during function calls, which
4542 make it harder to debug code in a shared library, than to debug the
4543 same code linked statically.
4547 GDB is now using the latest `getopt' routines from the FSF. This
4548 version accepts the -- prefix for options with long names. GDB will
4549 continue to accept the old forms (-option and +option) as well.
4550 Various single letter abbreviations for options have been explicity
4551 added to the option table so that they won't get overshadowed in the
4552 future by other options that begin with the same letter.
4556 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4557 Many assorted bugs have been handled. Many more remain to be handled.
4558 See the various ChangeLog files (primarily in gdb and bfd) for details.
4561 *** Changes in GDB-4.3:
4563 * New machines supported (host and target)
4565 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4566 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4567 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4569 * Almost SCO Unix support
4571 We had hoped to support:
4572 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4573 (except for core file support), but we discovered very late in the release
4574 that it has problems with process groups that render gdb unusable. Sorry
4575 about that. I encourage people to fix it and post the fixes.
4577 * Preliminary ELF and DWARF support
4579 GDB can read ELF object files on System V Release 4, and can handle
4580 debugging records for C, in DWARF format, in ELF files. This support
4581 is preliminary. If you bring up GDB on another SVR4 system, please
4582 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4587 GDB now uses the latest `readline' library. One user-visible change
4588 is that two tabs will list possible command completions, which previously
4589 required typing M-? (meta-question mark, or ESC ?).
4593 The `stepi' bug that many of you noticed has been squashed.
4594 Many bugs in C++ have been handled. Many more remain to be handled.
4595 See the various ChangeLog files (primarily in gdb and bfd) for details.
4597 * State of the MIPS world (in case you wondered):
4599 GDB can understand the symbol tables emitted by the compilers
4600 supplied by most vendors of MIPS-based machines, including DEC. These
4601 symbol tables are in a format that essentially nobody else uses.
4603 Some versions of gcc come with an assembler post-processor called
4604 mips-tfile. This program is required if you want to do source-level
4605 debugging of gcc-compiled programs. I believe FSF does not ship
4606 mips-tfile with gcc version 1, but it will eventually come with gcc
4609 Debugging of g++ output remains a problem. g++ version 1.xx does not
4610 really support it at all. (If you're lucky, you should be able to get
4611 line numbers and stack traces to work, but no parameters or local
4612 variables.) With some work it should be possible to improve the
4615 When gcc version 2 is released, you will have somewhat better luck.
4616 However, even then you will get confusing results for inheritance and
4619 We will eventually provide full debugging of g++ output on
4620 DECstations. This will probably involve some kind of stabs-in-ecoff
4621 encapulation, but the details have not been worked out yet.
4624 *** Changes in GDB-4.2:
4626 * Improved configuration
4628 Only one copy of `configure' exists now, and it is not self-modifying.
4629 Porting BFD is simpler.
4633 The `step' and `next' commands now only stop at the first instruction
4634 of a source line. This prevents the multiple stops that used to occur
4635 in switch statements, for-loops, etc. `Step' continues to stop if a
4636 function that has debugging information is called within the line.
4640 Lots of small bugs fixed. More remain.
4642 * New host supported (not target)
4644 Intel 386 PC clone running Mach i386-none-mach
4647 *** Changes in GDB-4.1:
4649 * Multiple source language support
4651 GDB now has internal scaffolding to handle several source languages.
4652 It determines the type of each source file from its filename extension,
4653 and will switch expression parsing and number formatting to match the
4654 language of the function in the currently selected stack frame.
4655 You can also specifically set the language to be used, with
4656 `set language c' or `set language modula-2'.
4660 GDB now has preliminary support for the GNU Modula-2 compiler,
4661 currently under development at the State University of New York at
4662 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4663 continue through the fall of 1991 and into 1992.
4665 Other Modula-2 compilers are currently not supported, and attempting to
4666 debug programs compiled with them will likely result in an error as the
4667 symbol table is read. Feel free to work on it, though!
4669 There are hooks in GDB for strict type checking and range checking,
4670 in the `Modula-2 philosophy', but they do not currently work.
4674 GDB can now write to executable and core files (e.g. patch
4675 a variable's value). You must turn this switch on, specify
4676 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4677 by assigning a new value to a variable. Modifications take
4680 * Automatic SunOS shared library reading
4682 When you run your program, GDB automatically determines where its
4683 shared libraries (if any) have been loaded, and reads their symbols.
4684 The `share' command is no longer needed. This also works when
4685 examining core files.
4689 You can specify the number of lines that the `list' command shows.
4692 * New machines supported (host and target)
4694 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4695 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4696 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4698 * New hosts supported (not targets)
4700 IBM RT/PC: romp-ibm-aix or rtpc
4702 * New targets supported (not hosts)
4704 AMD 29000 embedded with COFF a29k-none-coff
4705 AMD 29000 embedded with a.out a29k-none-aout
4706 Ultracomputer remote kernel debug a29k-nyu-kern
4708 * New remote interfaces
4714 *** Changes in GDB-4.0:
4718 Wide output is wrapped at good places to make the output more readable.
4720 Gdb now supports cross-debugging from a host machine of one type to a
4721 target machine of another type. Communication with the target system
4722 is over serial lines. The ``target'' command handles connecting to the
4723 remote system; the ``load'' command will download a program into the
4724 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4725 also supports debugging of realtime processes running under VxWorks,
4726 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4727 stub on the target system.
4729 New CPUs supported include the AMD 29000 and Intel 960.
4731 GDB now reads object files and symbol tables via a ``binary file''
4732 library, which allows a single copy of GDB to debug programs of multiple
4733 object file types such as a.out and coff.
4735 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4736 refcard.dvi and refcard.ps are available to format it).
4739 * Control-Variable user interface simplified
4741 All variables that control the operation of the debugger can be set
4742 by the ``set'' command, and displayed by the ``show'' command.
4744 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4745 ``Show prompt'' produces the response:
4746 Gdb's prompt is new-gdb=>.
4748 What follows are the NEW set commands. The command ``help set'' will
4749 print a complete list of old and new set commands. ``help set FOO''
4750 will give a longer description of the variable FOO. ``show'' will show
4751 all of the variable descriptions and their current settings.
4753 confirm on/off: Enables warning questions for operations that are
4754 hard to recover from, e.g. rerunning the program while
4755 it is already running. Default is ON.
4757 editing on/off: Enables EMACS style command line editing
4758 of input. Previous lines can be recalled with
4759 control-P, the current line can be edited with control-B,
4760 you can search for commands with control-R, etc.
4763 history filename NAME: NAME is where the gdb command history
4764 will be stored. The default is .gdb_history,
4765 or the value of the environment variable
4768 history size N: The size, in commands, of the command history. The
4769 default is 256, or the value of the environment variable
4772 history save on/off: If this value is set to ON, the history file will
4773 be saved after exiting gdb. If set to OFF, the
4774 file will not be saved. The default is OFF.
4776 history expansion on/off: If this value is set to ON, then csh-like
4777 history expansion will be performed on
4778 command line input. The default is OFF.
4780 radix N: Sets the default radix for input and output. It can be set
4781 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4782 in the current radix, so "set radix 10" is always a no-op.
4784 height N: This integer value is the number of lines on a page. Default
4785 is 24, the current `stty rows'' setting, or the ``li#''
4786 setting from the termcap entry matching the environment
4789 width N: This integer value is the number of characters on a line.
4790 Default is 80, the current `stty cols'' setting, or the ``co#''
4791 setting from the termcap entry matching the environment
4794 Note: ``set screensize'' is obsolete. Use ``set height'' and
4795 ``set width'' instead.
4797 print address on/off: Print memory addresses in various command displays,
4798 such as stack traces and structure values. Gdb looks
4799 more ``symbolic'' if you turn this off; it looks more
4800 ``machine level'' with it on. Default is ON.
4802 print array on/off: Prettyprint arrays. New convenient format! Default
4805 print demangle on/off: Print C++ symbols in "source" form if on,
4808 print asm-demangle on/off: Same, for assembler level printouts
4811 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4814 * Support for Epoch Environment.
4816 The epoch environment is a version of Emacs v18 with windowing. One
4817 new command, ``inspect'', is identical to ``print'', except that if you
4818 are running in the epoch environment, the value is printed in its own
4822 * Support for Shared Libraries
4824 GDB can now debug programs and core files that use SunOS shared libraries.
4825 Symbols from a shared library cannot be referenced
4826 before the shared library has been linked with the program (this
4827 happens after you type ``run'' and before the function main() is entered).
4828 At any time after this linking (including when examining core files
4829 from dynamically linked programs), gdb reads the symbols from each
4830 shared library when you type the ``sharedlibrary'' command.
4831 It can be abbreviated ``share''.
4833 sharedlibrary REGEXP: Load shared object library symbols for files
4834 matching a unix regular expression. No argument
4835 indicates to load symbols for all shared libraries.
4837 info sharedlibrary: Status of loaded shared libraries.
4842 A watchpoint stops execution of a program whenever the value of an
4843 expression changes. Checking for this slows down execution
4844 tremendously whenever you are in the scope of the expression, but is
4845 quite useful for catching tough ``bit-spreader'' or pointer misuse
4846 problems. Some machines such as the 386 have hardware for doing this
4847 more quickly, and future versions of gdb will use this hardware.
4849 watch EXP: Set a watchpoint (breakpoint) for an expression.
4851 info watchpoints: Information about your watchpoints.
4853 delete N: Deletes watchpoint number N (same as breakpoints).
4854 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4855 enable N: Re-enables watchpoint number N (same as breakpoints).
4858 * C++ multiple inheritance
4860 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4863 * C++ exception handling
4865 Gdb now supports limited C++ exception handling. Besides the existing
4866 ability to breakpoint on an exception handler, gdb can breakpoint on
4867 the raising of an exception (before the stack is peeled back to the
4870 catch FOO: If there is a FOO exception handler in the dynamic scope,
4871 set a breakpoint to catch exceptions which may be raised there.
4872 Multiple exceptions (``catch foo bar baz'') may be caught.
4874 info catch: Lists all exceptions which may be caught in the
4875 current stack frame.
4878 * Minor command changes
4880 The command ``call func (arg, arg, ...)'' now acts like the print
4881 command, except it does not print or save a value if the function's result
4882 is void. This is similar to dbx usage.
4884 The ``up'' and ``down'' commands now always print the frame they end up
4885 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4886 frames without printing.
4888 * New directory command
4890 'dir' now adds directories to the FRONT of the source search path.
4891 The path starts off empty. Source files that contain debug information
4892 about the directory in which they were compiled can be found even
4893 with an empty path; Sun CC and GCC include this information. If GDB can't
4894 find your source file in the current directory, type "dir .".
4896 * Configuring GDB for compilation
4898 For normal use, type ``./configure host''. See README or gdb.texinfo
4901 GDB now handles cross debugging. If you are remotely debugging between
4902 two different machines, type ``./configure host -target=targ''.
4903 Host is the machine where GDB will run; targ is the machine
4904 where the program that you are debugging will run.