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.
85 ** "catch load" and "catch unload" can be used to stop when a shared
86 library is loaded or unloaded, respectively.
88 ** "enable count" can be used to auto-disable a breakpoint after
91 ** "info vtbl" can be used to show the virtual method tables for
96 Renesas RL78 rl78-*-elf
97 HP OpenVMS ia64 ia64-hp-openvms*
99 * GDBserver supports evaluation of breakpoint conditions. When
100 support is advertised by GDBserver, GDB may be told to send the
101 breakpoint conditions in bytecode form to GDBserver. GDBserver
102 will only report the breakpoint trigger to GDB when its condition
107 set breakpoint condition-evaluation
108 show breakpoint condition-evaluation
109 Controls whether breakpoint conditions are evaluated by GDB ("host") or by
110 GDBserver ("target"). Default option "auto" chooses the most efficient
112 This option can improve debugger efficiency depending on the speed of the
117 z0/z1 conditional breakpoints extension
119 The z0/z1 breakpoint insertion packets have been extended to carry
120 a list of conditional expressions over to the remote stub depending on the
121 condition evaluation mode. The use of this extension can be controlled
122 via the "set remote conditional-breakpoints-packet" command.
126 Specify the signals which the remote stub may pass to the debugged
127 program without GDB involvement.
129 * New command line options
131 --init-command=FILE, -ix Like --command, -x but execute it
132 before loading inferior.
133 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
134 execute it before loading inferior.
136 *** Changes in GDB 7.4
138 * GDB now handles ambiguous linespecs more consistently; the existing
139 FILE:LINE support has been expanded to other types of linespecs. A
140 breakpoint will now be set on all matching locations in all
141 inferiors, and locations will be added or removed according to
144 * GDB now allows you to skip uninteresting functions and files when
145 stepping with the "skip function" and "skip file" commands.
147 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
148 and "show remote hardware-watchpoint-length-limit". These allows to
149 set or show the maximum length limit (in bytes) of a remote
150 target hardware watchpoint.
152 This allows e.g. to use "unlimited" hardware watchpoints with the
153 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
154 watchpoints are slower than real hardware watchpoints but are
155 significantly faster than gdb software watchpoints.
159 ** The register_pretty_printer function in module gdb.printing now takes
160 an optional `replace' argument. If True, the new printer replaces any
163 ** The "maint set python print-stack on|off" command has been
164 deprecated and will be deleted in GDB 7.5.
165 A new command: "set python print-stack none|full|message" has
166 replaced it. Additionally, the default for "print-stack" is
167 now "message", which just prints the error message without
170 ** A prompt substitution hook (prompt_hook) is now available to the
173 ** A new Python module, gdb.prompt has been added to the GDB Python
174 modules library. This module provides functionality for
175 escape sequences in prompts (used by set/show
176 extended-prompt). These escape sequences are replaced by their
179 ** Python commands and convenience-functions located in
180 'data-directory'/python/gdb/command and
181 'data-directory'/python/gdb/function are now automatically loaded
184 ** Blocks now provide four new attributes. global_block and
185 static_block will return the global and static blocks
186 respectively. is_static and is_global are boolean attributes
187 that indicate if the block is one of those two types.
189 ** Symbols now provide the "type" attribute, the type of the symbol.
191 ** The "gdb.breakpoint" function has been deprecated in favor of
194 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
195 of a function. This class is based on the "finish" command
196 available in the CLI.
198 ** Type objects for struct and union types now allow access to
199 the fields using standard Python dictionary (mapping) methods.
200 For example, "some_type['myfield']" now works, as does
203 ** A new event "gdb.new_objfile" has been added, triggered by loading a
206 ** A new function, "deep_items" has been added to the gdb.types
207 module in the GDB Python modules library. This function returns
208 an iterator over the fields of a struct or union type. Unlike
209 the standard Python "iteritems" method, it will recursively traverse
210 any anonymous fields.
214 ** "*stopped" events can report several new "reason"s, such as
217 ** Breakpoint changes are now notified using new async records, like
218 "=breakpoint-modified".
220 ** New command -ada-task-info.
222 * libthread-db-search-path now supports two special values: $sdir and $pdir.
223 $sdir specifies the default system locations of shared libraries.
224 $pdir specifies the directory where the libpthread used by the application
227 GDB no longer looks in $sdir and $pdir after it has searched the directories
228 mentioned in libthread-db-search-path. If you want to search those
229 directories, they must be specified in libthread-db-search-path.
230 The default value of libthread-db-search-path on GNU/Linux and Solaris
231 systems is now "$sdir:$pdir".
233 $pdir is not supported by gdbserver, it is currently ignored.
234 $sdir is supported by gdbserver.
236 * New configure option --with-iconv-bin.
237 When using the internationalization support like the one in the GNU C
238 library, GDB will invoke the "iconv" program to get a list of supported
239 character sets. If this program lives in a non-standard location, one can
240 use this option to specify where to find it.
242 * When natively debugging programs on PowerPC BookE processors running
243 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
244 watchpoints, which specify a mask in addition to an address to watch.
245 The mask specifies that some bits of an address (the bits which are
246 reset in the mask) should be ignored when matching the address accessed
247 by the inferior against the watchpoint address. See the "PowerPC Embedded"
248 section in the user manual for more details.
250 * The new option --once causes GDBserver to stop listening for connections once
251 the first connection is made. The listening port used by GDBserver will
252 become available after that.
254 * New commands "info macros" and "alias" have been added.
256 * New function parameters suffix @entry specifies value of function parameter
257 at the time the function got called. Entry values are available only since
263 "!" is now an alias of the "shell" command.
264 Note that no space is needed between "!" and SHELL COMMAND.
268 watch EXPRESSION mask MASK_VALUE
269 The watch command now supports the mask argument which allows creation
270 of masked watchpoints, if the current architecture supports this feature.
272 info auto-load-scripts [REGEXP]
273 This command was formerly named "maintenance print section-scripts".
274 It is now generally useful and is no longer a maintenance-only command.
276 info macro [-all] [--] MACRO
277 The info macro command has new options `-all' and `--'. The first for
278 printing all definitions of a macro. The second for explicitly specifying
279 the end of arguments and the beginning of the macro name in case the macro
280 name starts with a hyphen.
282 collect[/s] EXPRESSIONS
283 The tracepoint collect command now takes an optional modifier "/s"
284 that directs it to dereference pointer-to-character types and
285 collect the bytes of memory up to a zero byte. The behavior is
286 similar to what you see when you use the regular print command on a
287 string. An optional integer following the "/s" sets a bound on the
288 number of bytes that will be collected.
291 The trace start command now interprets any supplied arguments as a
292 note to be recorded with the trace run, with an effect similar to
293 setting the variable trace-notes.
296 The trace stop command now interprets any arguments as a note to be
297 mentioned along with the tstatus report that the trace was stopped
298 with a command. The effect is similar to setting the variable
301 * Tracepoints can now be enabled and disabled at any time after a trace
302 experiment has been started using the standard "enable" and "disable"
303 commands. It is now possible to start a trace experiment with no enabled
304 tracepoints; GDB will display a warning, but will allow the experiment to
305 begin, assuming that tracepoints will be enabled as needed while the trace
308 * Fast tracepoints on 32-bit x86-architectures can now be placed at
309 locations with 4-byte instructions, when they were previously
310 limited to locations with instructions of 5 bytes or longer.
316 Set the GDB prompt, and allow escape sequences to be inserted to
317 display miscellaneous information (see 'help set extended-prompt'
318 for the list of sequences). This prompt (and any information
319 accessed through the escape sequences) is updated every time the
322 set print entry-values (both|compact|default|if-needed|no|only|preferred)
323 show print entry-values
324 Set printing of frame argument values at function entry. In some cases
325 GDB can determine the value of function argument which was passed by the
326 function caller, even if the value was modified inside the called function.
328 set debug entry-values
329 show debug entry-values
330 Control display of debugging info for determining frame argument values at
331 function entry and virtual tail call frames.
333 set basenames-may-differ
334 show basenames-may-differ
335 Set whether a source file may have multiple base names.
336 (A "base name" is the name of a file with the directory part removed.
337 Example: The base name of "/home/user/hello.c" is "hello.c".)
338 If set, GDB will canonicalize file names (e.g., expand symlinks)
339 before comparing them. Canonicalization is an expensive operation,
340 but it allows the same file be known by more than one base name.
341 If not set (the default), all source files are assumed to have just
342 one base name, and gdb will do file name comparisons more efficiently.
348 Set a user name and notes for the current and any future trace runs.
349 This is useful for long-running and/or disconnected traces, to
350 inform others (or yourself) as to who is running the trace, supply
351 contact information, or otherwise explain what is going on.
354 show trace-stop-notes
355 Set a note attached to the trace run, that is displayed when the
356 trace has been stopped by a tstop command. This is useful for
357 instance as an explanation, if you are stopping a trace run that was
358 started by someone else.
364 Dynamically enable a tracepoint in a started trace experiment.
368 Dynamically disable a tracepoint in a started trace experiment.
372 Set the user and notes of the trace run.
376 Query the current status of a tracepoint.
380 Query the minimum length of instruction at which a fast tracepoint may
383 * Dcache size (number of lines) and line-size are now runtime-configurable
384 via "set dcache line" and "set dcache line-size" commands.
388 Texas Instruments TMS320C6x tic6x-*-*
392 Renesas RL78 rl78-*-elf
394 *** Changes in GDB 7.3.1
396 * The build failure for NetBSD and OpenBSD targets have now been fixed.
398 *** Changes in GDB 7.3
400 * GDB has a new command: "thread find [REGEXP]".
401 It finds the thread id whose name, target id, or thread extra info
402 matches the given regular expression.
404 * The "catch syscall" command now works on mips*-linux* targets.
406 * The -data-disassemble MI command now supports modes 2 and 3 for
407 dumping the instruction opcodes.
409 * New command line options
411 -data-directory DIR Specify DIR as the "data-directory".
412 This is mostly for testing purposes.
414 * The "maint set python auto-load on|off" command has been renamed to
415 "set auto-load-scripts on|off".
417 * GDB has a new command: "set directories".
418 It is like the "dir" command except that it replaces the
419 source path list instead of augmenting it.
421 * GDB now understands thread names.
423 On GNU/Linux, "info threads" will display the thread name as set by
424 prctl or pthread_setname_np.
426 There is also a new command, "thread name", which can be used to
427 assign a name internally for GDB to display.
430 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
431 has been integrated into GDB.
435 ** The function gdb.Write now accepts an optional keyword 'stream'.
436 This keyword, when provided, will direct the output to either
437 stdout, stderr, or GDB's logging output.
439 ** Parameters can now be be sub-classed in Python, and in particular
440 you may implement the get_set_doc and get_show_doc functions.
441 This improves how Parameter set/show documentation is processed
442 and allows for more dynamic content.
444 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
445 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
446 have an is_valid method.
448 ** Breakpoints can now be sub-classed in Python, and in particular
449 you may implement a 'stop' function that is executed each time
450 the inferior reaches that breakpoint.
452 ** New function gdb.lookup_global_symbol looks up a global symbol.
454 ** GDB values in Python are now callable if the value represents a
455 function. For example, if 'some_value' represents a function that
456 takes two integer parameters and returns a value, you can call
457 that function like so:
459 result = some_value (10,20)
461 ** Module gdb.types has been added.
462 It contains a collection of utilities for working with gdb.Types objects:
463 get_basic_type, has_field, make_enum_dict.
465 ** Module gdb.printing has been added.
466 It contains utilities for writing and registering pretty-printers.
467 New classes: PrettyPrinter, SubPrettyPrinter,
468 RegexpCollectionPrettyPrinter.
469 New function: register_pretty_printer.
471 ** New commands "info pretty-printers", "enable pretty-printer" and
472 "disable pretty-printer" have been added.
474 ** gdb.parameter("directories") is now available.
476 ** New function gdb.newest_frame returns the newest frame in the
479 ** The gdb.InferiorThread class has a new "name" attribute. This
480 holds the thread's name.
482 ** Python Support for Inferior events.
483 Python scripts can add observers to be notified of events
484 occurring in the process being debugged.
485 The following events are currently supported:
486 - gdb.events.cont Continue event.
487 - gdb.events.exited Inferior exited event.
488 - gdb.events.stop Signal received, and Breakpoint hit events.
492 ** GDB now puts template parameters in scope when debugging in an
493 instantiation. For example, if you have:
495 template<int X> int func (void) { return X; }
497 then if you step into func<5>, "print X" will show "5". This
498 feature requires proper debuginfo support from the compiler; it
499 was added to GCC 4.5.
501 ** The motion commands "next", "finish", "until", and "advance" now
502 work better when exceptions are thrown. In particular, GDB will
503 no longer lose control of the inferior; instead, the GDB will
504 stop the inferior at the point at which the exception is caught.
505 This functionality requires a change in the exception handling
506 code that was introduced in GCC 4.5.
508 * GDB now follows GCC's rules on accessing volatile objects when
509 reading or writing target state during expression evaluation.
510 One notable difference to prior behavior is that "print x = 0"
511 no longer generates a read of x; the value of the assignment is
512 now always taken directly from the value being assigned.
514 * GDB now has some support for using labels in the program's source in
515 linespecs. For instance, you can use "advance label" to continue
516 execution to a label.
518 * GDB now has support for reading and writing a new .gdb_index
519 section. This section holds a fast index of DWARF debugging
520 information and can be used to greatly speed up GDB startup and
521 operation. See the documentation for `save gdb-index' for details.
523 * The "watch" command now accepts an optional "-location" argument.
524 When used, this causes GDB to watch the memory referred to by the
525 expression. Such a watchpoint is never deleted due to it going out
528 * GDB now supports thread debugging of core dumps on GNU/Linux.
530 GDB now activates thread debugging using the libthread_db library
531 when debugging GNU/Linux core dumps, similarly to when debugging
532 live processes. As a result, when debugging a core dump file, GDB
533 is now able to display pthread_t ids of threads. For example, "info
534 threads" shows the same output as when debugging the process when it
535 was live. In earlier releases, you'd see something like this:
538 * 1 LWP 6780 main () at main.c:10
540 While now you see this:
543 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
545 It is also now possible to inspect TLS variables when debugging core
548 When debugging a core dump generated on a machine other than the one
549 used to run GDB, you may need to point GDB at the correct
550 libthread_db library with the "set libthread-db-search-path"
551 command. See the user manual for more details on this command.
553 * When natively debugging programs on PowerPC BookE processors running
554 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
555 which stop execution of the inferior whenever it executes an instruction
556 at any address within the specified range. See the "PowerPC Embedded"
557 section in the user manual for more details.
559 * New features in the GDB remote stub, GDBserver
561 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
562 and i686 LynxOS (version 5.x).
564 ** GDBserver is now supported on Blackfin Linux.
566 * New native configurations
568 ia64 HP-UX ia64-*-hpux*
572 Analog Devices, Inc. Blackfin Processor bfin-*
574 * Ada task switching is now supported on sparc-elf targets when
575 debugging a program using the Ravenscar Profile. For more information,
576 see the "Tasking Support when using the Ravenscar Profile" section
577 in the GDB user manual.
579 * Guile support was removed.
581 * New features in the GNU simulator
583 ** The --map-info flag lists all known core mappings.
585 ** CFI flashes may be simulated via the "cfi" device.
587 *** Changes in GDB 7.2
589 * Shared library support for remote targets by default
591 When GDB is configured for a generic, non-OS specific target, like
592 for example, --target=arm-eabi or one of the many *-*-elf targets,
593 GDB now queries remote stubs for loaded shared libraries using the
594 `qXfer:libraries:read' packet. Previously, shared library support
595 was always disabled for such configurations.
599 ** Argument Dependent Lookup (ADL)
601 In C++ ADL lookup directs function search to the namespaces of its
602 arguments even if the namespace has not been imported.
612 Here the compiler will search for `foo' in the namespace of 'b'
613 and find A::foo. GDB now supports this. This construct is commonly
614 used in the Standard Template Library for operators.
616 ** Improved User Defined Operator Support
618 In addition to member operators, GDB now supports lookup of operators
619 defined in a namespace and imported with a `using' directive, operators
620 defined in the global scope, operators imported implicitly from an
621 anonymous namespace, and the ADL operators mentioned in the previous
623 GDB now also supports proper overload resolution for all the previously
624 mentioned flavors of operators.
626 ** static const class members
628 Printing of static const class members that are initialized in the
629 class definition has been fixed.
631 * Windows Thread Information Block access.
633 On Windows targets, GDB now supports displaying the Windows Thread
634 Information Block (TIB) structure. This structure is visible either
635 by using the new command `info w32 thread-information-block' or, by
636 dereferencing the new convenience variable named `$_tlb', a
637 thread-specific pointer to the TIB. This feature is also supported
638 when remote debugging using GDBserver.
642 Static tracepoints are calls in the user program into a tracing
643 library. One such library is a port of the LTTng kernel tracer to
644 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
645 When debugging with GDBserver, GDB now supports combining the GDB
646 tracepoint machinery with such libraries. For example: the user can
647 use GDB to probe a static tracepoint marker (a call from the user
648 program into the tracing library) with the new "strace" command (see
649 "New commands" below). This creates a "static tracepoint" in the
650 breakpoint list, that can be manipulated with the same feature set
651 as fast and regular tracepoints. E.g., collect registers, local and
652 global variables, collect trace state variables, and define
653 tracepoint conditions. In addition, the user can collect extra
654 static tracepoint marker specific data, by collecting the new
655 $_sdata internal variable. When analyzing the trace buffer, you can
656 inspect $_sdata like any other variable available to GDB. For more
657 information, see the "Tracepoints" chapter in GDB user manual. New
658 remote packets have been defined to support static tracepoints, see
659 the "New remote packets" section below.
661 * Better reconstruction of tracepoints after disconnected tracing
663 GDB will attempt to download the original source form of tracepoint
664 definitions when starting a trace run, and then will upload these
665 upon reconnection to the target, resulting in a more accurate
666 reconstruction of the tracepoints that are in use on the target.
670 You can now exercise direct control over the ways that GDB can
671 affect your program. For instance, you can disallow the setting of
672 breakpoints, so that the program can run continuously (assuming
673 non-stop mode). In addition, the "observer" variable is available
674 to switch all of the different controls; in observer mode, GDB
675 cannot affect the target's behavior at all, which is useful for
676 tasks like diagnosing live systems in the field.
678 * The new convenience variable $_thread holds the number of the
685 Return the address of the Windows Thread Information Block of a given thread.
689 In response to several of the tracepoint packets, the target may now
690 also respond with a number of intermediate `qRelocInsn' request
691 packets before the final result packet, to have GDB handle
692 relocating an instruction to execute at a different address. This
693 is particularly useful for stubs that support fast tracepoints. GDB
694 reports support for this feature in the qSupported packet.
698 List static tracepoint markers in the target program.
702 List static tracepoint markers at a given address in the target
705 qXfer:statictrace:read
707 Read the static trace data collected (by a `collect $_sdata'
708 tracepoint action). The remote stub reports support for this packet
709 to gdb's qSupported query.
713 Send the current settings of GDB's permission flags.
717 Send part of the source (textual) form of a tracepoint definition,
718 which includes location, conditional, and action list.
720 * The source command now accepts a -s option to force searching for the
721 script in the source search path even if the script name specifies
724 * New features in the GDB remote stub, GDBserver
726 - GDBserver now support tracepoints (including fast tracepoints, and
727 static tracepoints). The feature is currently supported by the
728 i386-linux and amd64-linux builds. See the "Tracepoints support
729 in gdbserver" section in the manual for more information.
731 GDBserver JIT compiles the tracepoint's conditional agent
732 expression bytecode into native code whenever possible for low
733 overhead dynamic tracepoints conditionals. For such tracepoints,
734 an expression that examines program state is evaluated when the
735 tracepoint is reached, in order to determine whether to capture
736 trace data. If the condition is simple and false, processing the
737 tracepoint finishes very quickly and no data is gathered.
739 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
740 for static tracepoints support.
742 - GDBserver now supports x86_64 Windows 64-bit debugging.
744 * GDB now sends xmlRegisters= in qSupported packet to indicate that
745 it understands register description.
747 * The --batch flag now disables pagination and queries.
749 * X86 general purpose registers
751 GDB now supports reading/writing byte, word and double-word x86
752 general purpose registers directly. This means you can use, say,
753 $ah or $ax to refer, respectively, to the byte register AH and
754 16-bit word register AX that are actually portions of the 32-bit
755 register EAX or 64-bit register RAX.
757 * The `commands' command now accepts a range of breakpoints to modify.
758 A plain `commands' following a command that creates multiple
759 breakpoints affects all the breakpoints set by that command. This
760 applies to breakpoints set by `rbreak', and also applies when a
761 single `break' command creates multiple breakpoints (e.g.,
762 breakpoints on overloaded c++ functions).
764 * The `rbreak' command now accepts a filename specification as part of
765 its argument, limiting the functions selected by the regex to those
766 in the specified file.
768 * Support for remote debugging Windows and SymbianOS shared libraries
769 from Unix hosts has been improved. Non Windows GDB builds now can
770 understand target reported file names that follow MS-DOS based file
771 system semantics, such as file names that include drive letters and
772 use the backslash character as directory separator. This makes it
773 possible to transparently use the "set sysroot" and "set
774 solib-search-path" on Unix hosts to point as host copies of the
775 target's shared libraries. See the new command "set
776 target-file-system-kind" described below, and the "Commands to
777 specify files" section in the user manual for more information.
781 eval template, expressions...
782 Convert the values of one or more expressions under the control
783 of the string template to a command line, and call it.
785 set target-file-system-kind unix|dos-based|auto
786 show target-file-system-kind
787 Set or show the assumed file system kind for target reported file
790 save breakpoints <filename>
791 Save all current breakpoint definitions to a file suitable for use
792 in a later debugging session. To read the saved breakpoint
793 definitions, use the `source' command.
795 `save tracepoints' is a new alias for `save-tracepoints'. The latter
798 info static-tracepoint-markers
799 Display information about static tracepoint markers in the target.
801 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
802 Define a static tracepoint by probing a marker at the given
803 function, line, address, or marker ID.
807 Enable and disable observer mode.
809 set may-write-registers on|off
810 set may-write-memory on|off
811 set may-insert-breakpoints on|off
812 set may-insert-tracepoints on|off
813 set may-insert-fast-tracepoints on|off
814 set may-interrupt on|off
815 Set individual permissions for GDB effects on the target. Note that
816 some of these settings can have undesirable or surprising
817 consequences, particularly when changed in the middle of a session.
818 For instance, disabling the writing of memory can prevent
819 breakpoints from being inserted, cause single-stepping to fail, or
820 even crash your program, if you disable after breakpoints have been
821 inserted. However, GDB should not crash.
823 set record memory-query on|off
824 show record memory-query
825 Control whether to stop the inferior if memory changes caused
826 by an instruction cannot be recorded.
831 The disassemble command now supports "start,+length" form of two arguments.
835 ** GDB now provides a new directory location, called the python directory,
836 where Python scripts written for GDB can be installed. The location
837 of that directory is <data-directory>/python, where <data-directory>
838 is the GDB data directory. For more details, see section `Scripting
839 GDB using Python' in the manual.
841 ** The GDB Python API now has access to breakpoints, symbols, symbol
842 tables, program spaces, inferiors, threads and frame's code blocks.
843 Additionally, GDB Parameters can now be created from the API, and
844 manipulated via set/show in the CLI.
846 ** New functions gdb.target_charset, gdb.target_wide_charset,
847 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
849 ** New exception gdb.GdbError.
851 ** Pretty-printers are now also looked up in the current program space.
853 ** Pretty-printers can now be individually enabled and disabled.
855 ** GDB now looks for names of Python scripts to auto-load in a
856 special section named `.debug_gdb_scripts', in addition to looking
857 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
859 * Tracepoint actions were unified with breakpoint commands. In particular,
860 there are no longer differences in "info break" output for breakpoints and
861 tracepoints and the "commands" command can be used for both tracepoints and
866 ARM Symbian arm*-*-symbianelf*
868 * D language support.
869 GDB now supports debugging programs written in the D programming
872 * GDB now supports the extended ptrace interface for PowerPC which is
873 available since Linux kernel version 2.6.34. This automatically enables
874 any hardware breakpoints and additional hardware watchpoints available in
875 the processor. The old ptrace interface exposes just one hardware
876 watchpoint and no hardware breakpoints.
878 * GDB is now able to use the Data Value Compare (DVC) register available on
879 embedded PowerPC processors to implement in hardware simple watchpoint
880 conditions of the form:
882 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
884 This works in native GDB running on Linux kernels with the extended ptrace
885 interface mentioned above.
887 *** Changes in GDB 7.1
893 GDB now supports importing of namespaces in C++. This enables the
894 user to inspect variables from imported namespaces. Support for
895 namepace aliasing has also been added. So, if a namespace is
896 aliased in the current scope (e.g. namepace C=A; ) the user can
897 print variables using the alias (e.g. (gdb) print C::x).
901 All known bugs relating to the printing of virtual base class were
902 fixed. It is now possible to call overloaded static methods using a
907 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
908 and reinterpret_cast<> are now handled by the C++ expression parser.
912 Xilinx MicroBlaze microblaze-*-*
917 Xilinx MicroBlaze microblaze
920 * Multi-program debugging.
922 GDB now has support for multi-program (a.k.a. multi-executable or
923 multi-exec) debugging. This allows for debugging multiple inferiors
924 simultaneously each running a different program under the same GDB
925 session. See "Debugging Multiple Inferiors and Programs" in the
926 manual for more information. This implied some user visible changes
927 in the multi-inferior support. For example, "info inferiors" now
928 lists inferiors that are not running yet or that have exited
929 already. See also "New commands" and "New options" below.
931 * New tracing features
933 GDB's tracepoint facility now includes several new features:
935 ** Trace state variables
937 GDB tracepoints now include support for trace state variables, which
938 are variables managed by the target agent during a tracing
939 experiment. They are useful for tracepoints that trigger each
940 other, so for instance one tracepoint can count hits in a variable,
941 and then a second tracepoint has a condition that is true when the
942 count reaches a particular value. Trace state variables share the
943 $-syntax of GDB convenience variables, and can appear in both
944 tracepoint actions and condition expressions. Use the "tvariable"
945 command to create, and "info tvariables" to view; see "Trace State
946 Variables" in the manual for more detail.
950 GDB now includes an option for defining fast tracepoints, which
951 targets may implement more efficiently, such as by installing a jump
952 into the target agent rather than a trap instruction. The resulting
953 speedup can be by two orders of magnitude or more, although the
954 tradeoff is that some program locations on some target architectures
955 might not allow fast tracepoint installation, for instance if the
956 instruction to be replaced is shorter than the jump. To request a
957 fast tracepoint, use the "ftrace" command, with syntax identical to
958 the regular trace command.
960 ** Disconnected tracing
962 It is now possible to detach GDB from the target while it is running
963 a trace experiment, then reconnect later to see how the experiment
964 is going. In addition, a new variable disconnected-tracing lets you
965 tell the target agent whether to continue running a trace if the
966 connection is lost unexpectedly.
970 GDB now has the ability to save the trace buffer into a file, and
971 then use that file as a target, similarly to you can do with
972 corefiles. You can select trace frames, print data that was
973 collected in them, and use tstatus to display the state of the
974 tracing run at the moment that it was saved. To create a trace
975 file, use "tsave <filename>", and to use it, do "target tfile
978 ** Circular trace buffer
980 You can ask the target agent to handle the trace buffer as a
981 circular buffer, discarding the oldest trace frames to make room for
982 newer ones, by setting circular-trace-buffer to on. This feature may
983 not be available for all target agents.
988 The disassemble command, when invoked with two arguments, now requires
989 the arguments to be comma-separated.
992 The info variables command now displays variable definitions. Files
993 which only declare a variable are not shown.
996 The source command is now capable of sourcing Python scripts.
997 This feature is dependent on the debugger being build with Python
1000 Related to this enhancement is also the introduction of a new command
1001 "set script-extension" (see below).
1003 * New commands (for set/show, see "New options" below)
1005 record save [<FILENAME>]
1006 Save a file (in core file format) containing the process record
1007 execution log for replay debugging at a later time.
1009 record restore <FILENAME>
1010 Restore the process record execution log that was saved at an
1011 earlier time, for replay debugging.
1013 add-inferior [-copies <N>] [-exec <FILENAME>]
1016 clone-inferior [-copies <N>] [ID]
1017 Make a new inferior ready to execute the same program another
1018 inferior has loaded.
1023 maint info program-spaces
1024 List the program spaces loaded into GDB.
1026 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1027 show remote interrupt-sequence
1028 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1029 as the sequence to the remote target in order to interrupt the execution.
1030 Ctrl-C is a default. Some system prefers BREAK which is high level of
1031 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1032 Magic SysRq g. It is BREAK signal and character 'g'.
1034 set remote interrupt-on-connect [on | off]
1035 show remote interrupt-on-connect
1036 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1037 remote target when gdb connects to it. This is needed when you debug
1040 set remotebreak [on | off]
1042 Deprecated. Use "set/show remote interrupt-sequence" instead.
1044 tvariable $NAME [ = EXP ]
1045 Create or modify a trace state variable.
1048 List trace state variables and their values.
1050 delete tvariable $NAME ...
1051 Delete one or more trace state variables.
1054 Evaluate the given expressions without collecting anything into the
1055 trace buffer. (Valid in tracepoint actions only.)
1057 ftrace FN / FILE:LINE / *ADDR
1058 Define a fast tracepoint at the given function, line, or address.
1060 * New expression syntax
1062 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1063 GDB now parses 0b101010 identically with 42.
1067 set follow-exec-mode new|same
1068 show follow-exec-mode
1069 Control whether GDB reuses the same inferior across an exec call or
1070 creates a new one. This is useful to be able to restart the old
1071 executable after the inferior having done an exec call.
1073 set default-collect EXPR, ...
1074 show default-collect
1075 Define a list of expressions to be collected at each tracepoint.
1076 This is a useful way to ensure essential items are not overlooked,
1077 such as registers or a critical global variable.
1079 set disconnected-tracing
1080 show disconnected-tracing
1081 If set to 1, the target is instructed to continue tracing if it
1082 loses its connection to GDB. If 0, the target is to stop tracing
1085 set circular-trace-buffer
1086 show circular-trace-buffer
1087 If set to on, the target is instructed to use a circular trace buffer
1088 and discard the oldest trace frames instead of stopping the trace due
1089 to a full trace buffer. If set to off, the trace stops when the buffer
1090 fills up. Some targets may not support this.
1092 set script-extension off|soft|strict
1093 show script-extension
1094 If set to "off", the debugger does not perform any script language
1095 recognition, and all sourced files are assumed to be GDB scripts.
1096 If set to "soft" (the default), files are sourced according to
1097 filename extension, falling back to GDB scripts if the first
1099 If set to "strict", files are sourced according to filename extension.
1101 set ada trust-PAD-over-XVS on|off
1102 show ada trust-PAD-over-XVS
1103 If off, activate a workaround against a bug in the debugging information
1104 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1105 the GCC sources for more information about the GNAT encoding and
1106 PAD types in particular). It is always safe to set this option to
1107 off, but this introduces a slight performance penalty. The default
1110 * Python API Improvements
1112 ** GDB provides the new class gdb.LazyString. This is useful in
1113 some pretty-printing cases. The new method gdb.Value.lazy_string
1114 provides a simple way to create objects of this type.
1116 ** The fields returned by gdb.Type.fields now have an
1117 `is_base_class' attribute.
1119 ** The new method gdb.Type.range returns the range of an array type.
1121 ** The new method gdb.parse_and_eval can be used to parse and
1122 evaluate an expression.
1124 * New remote packets
1127 Define a trace state variable.
1130 Get the current value of a trace state variable.
1133 Set desired tracing behavior upon disconnection.
1136 Set the trace buffer to be linear or circular.
1139 Get data about the tracepoints currently in use.
1143 Process record now works correctly with hardware watchpoints.
1145 Multiple bug fixes have been made to the mips-irix port, making it
1146 much more reliable. In particular:
1147 - Debugging threaded applications is now possible again. Previously,
1148 GDB would hang while starting the program, or while waiting for
1149 the program to stop at a breakpoint.
1150 - Attaching to a running process no longer hangs.
1151 - An error occurring while loading a core file has been fixed.
1152 - Changing the value of the PC register now works again. This fixes
1153 problems observed when using the "jump" command, or when calling
1154 a function from GDB, or even when assigning a new value to $pc.
1155 - With the "finish" and "return" commands, the return value for functions
1156 returning a small array is now correctly printed.
1157 - It is now possible to break on shared library code which gets executed
1158 during a shared library init phase (code executed while executing
1159 their .init section). Previously, the breakpoint would have no effect.
1160 - GDB is now able to backtrace through the signal handler for
1161 non-threaded programs.
1163 PIE (Position Independent Executable) programs debugging is now supported.
1164 This includes debugging execution of PIC (Position Independent Code) shared
1165 libraries although for that, it should be possible to run such libraries as an
1168 *** Changes in GDB 7.0
1170 * GDB now has an interface for JIT compilation. Applications that
1171 dynamically generate code can create symbol files in memory and register
1172 them with GDB. For users, the feature should work transparently, and
1173 for JIT developers, the interface is documented in the GDB manual in the
1174 "JIT Compilation Interface" chapter.
1176 * Tracepoints may now be conditional. The syntax is as for
1177 breakpoints; either an "if" clause appended to the "trace" command,
1178 or the "condition" command is available. GDB sends the condition to
1179 the target for evaluation using the same bytecode format as is used
1180 for tracepoint actions.
1182 * The disassemble command now supports: an optional /r modifier, print the
1183 raw instructions in hex as well as in symbolic form, and an optional /m
1184 modifier to print mixed source+assembly.
1186 * Process record and replay
1188 In a architecture environment that supports ``process record and
1189 replay'', ``process record and replay'' target can record a log of
1190 the process execution, and replay it with both forward and reverse
1193 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1194 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1195 set execution-direction {forward|reverse}, for targets that support
1198 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1199 feature is available with a native GDB running on kernel version
1202 * GDB now has support for multi-byte and wide character sets on the
1203 target. Strings whose character type is wchar_t, char16_t, or
1204 char32_t are now correctly printed. GDB supports wide- and unicode-
1205 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1206 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1207 `printf'. This feature requires iconv to work properly; if your
1208 system does not have a working iconv, GDB can use GNU libiconv. See
1209 the installation instructions for more information.
1211 * GDB now supports automatic retrieval of shared library files from
1212 remote targets. To use this feature, specify a system root that begins
1213 with the `remote:' prefix, either via the `set sysroot' command or via
1214 the `--with-sysroot' configure-time option.
1216 * "info sharedlibrary" now takes an optional regex of libraries to show,
1217 and it now reports if a shared library has no debugging information.
1219 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1220 now complete on file names.
1222 * When completing in expressions, gdb will attempt to limit
1223 completions to allowable structure or union fields, where appropriate.
1224 For instance, consider:
1226 # struct example { int f1; double f2; };
1227 # struct example variable;
1230 If the user types TAB at the end of this command line, the available
1231 completions will be "f1" and "f2".
1233 * Inlined functions are now supported. They show up in backtraces, and
1234 the "step", "next", and "finish" commands handle them automatically.
1236 * GDB now supports the token-splicing (##) and stringification (#)
1237 operators when expanding macros. It also supports variable-arity
1240 * GDB now supports inspecting extra signal information, exported by
1241 the new $_siginfo convenience variable. The feature is currently
1242 implemented on linux ARM, i386 and amd64.
1244 * GDB can now display the VFP floating point registers and NEON vector
1245 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1246 can provide these registers (requires Linux 2.6.30 or later). Remote
1247 and simulator targets may also provide them.
1249 * New remote packets
1252 Search memory for a sequence of bytes.
1255 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1256 operation over reliable transport links. Use of this packet is
1257 controlled by the `set remote noack-packet' command.
1260 Kill the process with the specified process ID. Use this in preference
1261 to `k' when multiprocess protocol extensions are supported.
1264 Obtains additional operating system information
1268 Read or write additional signal information.
1270 * Removed remote protocol undocumented extension
1272 An undocumented extension to the remote protocol's `S' stop reply
1273 packet that permited the stub to pass a process id was removed.
1274 Remote servers should use the `T' stop reply packet instead.
1276 * GDB now supports multiple function calling conventions according to the
1277 DWARF-2 DW_AT_calling_convention function attribute.
1279 * The SH target utilizes the aforementioned change to distinguish between gcc
1280 and Renesas calling convention. It also adds the new CLI commands
1281 `set/show sh calling-convention'.
1283 * GDB can now read compressed debug sections, as produced by GNU gold
1284 with the --compress-debug-sections=zlib flag.
1286 * 64-bit core files are now supported on AIX.
1288 * Thread switching is now supported on Tru64.
1290 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1291 which will be allocated using malloc later in program execution.
1293 * The qXfer:libraries:read remote procotol packet now allows passing a
1294 list of section offsets.
1296 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1297 conditions handling signals delivered during attach or thread creation
1298 have also been fixed.
1300 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1301 From the user's standpoint, all unqualified instances of True and False
1302 are treated as the standard definitions, regardless of context.
1304 * GDB now parses C++ symbol and type names more flexibly. For
1307 template<typename T> class C { };
1310 GDB will now correctly handle all of:
1312 ptype C<char const *>
1313 ptype C<char const*>
1314 ptype C<const char *>
1315 ptype C<const char*>
1317 * New features in the GDB remote stub, gdbserver
1319 - The "--wrapper" command-line argument tells gdbserver to use a
1320 wrapper program to launch programs for debugging.
1322 - On PowerPC and S/390 targets, it is now possible to use a single
1323 gdbserver executable to debug both 32-bit and 64-bit programs.
1324 (This requires gdbserver itself to be built as a 64-bit executable.)
1326 - gdbserver uses the new noack protocol mode for TCP connections to
1327 reduce communications latency, if also supported and enabled in GDB.
1329 - Support for the sparc64-linux-gnu target is now included in
1332 - The amd64-linux build of gdbserver now supports debugging both
1333 32-bit and 64-bit programs.
1335 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1336 now support hardware watchpoints, and will use them automatically
1341 GDB now has support for scripting using Python. Whether this is
1342 available is determined at configure time.
1344 New GDB commands can now be written in Python.
1346 * Ada tasking support
1348 Ada tasks can now be inspected in GDB. The following commands have
1352 Print the list of Ada tasks.
1354 Print detailed information about task number N.
1356 Print the task number of the current task.
1358 Switch the context of debugging to task number N.
1360 * Support for user-defined prefixed commands. The "define" command can
1361 add new commands to existing prefixes, e.g. "target".
1363 * Multi-inferior, multi-process debugging.
1365 GDB now has generalized support for multi-inferior debugging. See
1366 "Debugging Multiple Inferiors" in the manual for more information.
1367 Although availability still depends on target support, the command
1368 set is more uniform now. The GNU/Linux specific multi-forks support
1369 has been migrated to this new framework. This implied some user
1370 visible changes; see "New commands" and also "Removed commands"
1373 * Target descriptions can now describe the target OS ABI. See the
1374 "Target Description Format" section in the user manual for more
1377 * Target descriptions can now describe "compatible" architectures
1378 to indicate that the target can execute applications for a different
1379 architecture in addition to those for the main target architecture.
1380 See the "Target Description Format" section in the user manual for
1383 * Multi-architecture debugging.
1385 GDB now includes general supports for debugging applications on
1386 hybrid systems that use more than one single processor architecture
1387 at the same time. Each such hybrid architecture still requires
1388 specific support to be added. The only hybrid architecture supported
1389 in this version of GDB is the Cell Broadband Engine.
1391 * GDB now supports integrated debugging of Cell/B.E. applications that
1392 use both the PPU and SPU architectures. To enable support for hybrid
1393 Cell/B.E. debugging, you need to configure GDB to support both the
1394 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1395 --enable-targets configure option.
1397 * Non-stop mode debugging.
1399 For some targets, GDB now supports an optional mode of operation in
1400 which you can examine stopped threads while other threads continue
1401 to execute freely. This is referred to as non-stop mode, with the
1402 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1403 section in the user manual for more information.
1405 To be able to support remote non-stop debugging, a remote stub needs
1406 to implement the non-stop mode remote protocol extensions, as
1407 described in the "Remote Non-Stop" section of the user manual. The
1408 GDB remote stub, gdbserver, has been adjusted to support these
1409 extensions on linux targets.
1411 * New commands (for set/show, see "New options" below)
1413 catch syscall [NAME(S) | NUMBER(S)]
1414 Catch system calls. Arguments, which should be names of system
1415 calls or their numbers, mean catch only those syscalls. Without
1416 arguments, every syscall will be caught. When the inferior issues
1417 any of the specified syscalls, GDB will stop and announce the system
1418 call, both when it is called and when its call returns. This
1419 feature is currently available with a native GDB running on the
1420 Linux Kernel, under the following architectures: x86, x86_64,
1421 PowerPC and PowerPC64.
1423 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1425 Search memory for a sequence of bytes.
1427 maint set python print-stack
1428 maint show python print-stack
1429 Show a stack trace when an error is encountered in a Python script.
1432 Invoke CODE by passing it to the Python interpreter.
1437 These allow macros to be defined, undefined, and listed
1441 Show operating system information about processes.
1444 List the inferiors currently under GDB's control.
1447 Switch focus to inferior number NUM.
1450 Detach from inferior number NUM.
1453 Kill inferior number NUM.
1457 set spu stop-on-load
1458 show spu stop-on-load
1459 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1461 set spu auto-flush-cache
1462 show spu auto-flush-cache
1463 Control whether to automatically flush the software-managed cache
1464 during Cell/B.E. debugging.
1466 set sh calling-convention
1467 show sh calling-convention
1468 Control the calling convention used when calling SH target functions.
1471 show debug timestamp
1472 Control display of timestamps with GDB debugging output.
1474 set disassemble-next-line
1475 show disassemble-next-line
1476 Control display of disassembled source lines or instructions when
1479 set remote noack-packet
1480 show remote noack-packet
1481 Set/show the use of remote protocol QStartNoAckMode packet. See above
1482 under "New remote packets."
1484 set remote query-attached-packet
1485 show remote query-attached-packet
1486 Control use of remote protocol `qAttached' (query-attached) packet.
1488 set remote read-siginfo-object
1489 show remote read-siginfo-object
1490 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1493 set remote write-siginfo-object
1494 show remote write-siginfo-object
1495 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1498 set remote reverse-continue
1499 show remote reverse-continue
1500 Control use of remote protocol 'bc' (reverse-continue) packet.
1502 set remote reverse-step
1503 show remote reverse-step
1504 Control use of remote protocol 'bs' (reverse-step) packet.
1506 set displaced-stepping
1507 show displaced-stepping
1508 Control displaced stepping mode. Displaced stepping is a way to
1509 single-step over breakpoints without removing them from the debuggee.
1510 Also known as "out-of-line single-stepping".
1513 show debug displaced
1514 Control display of debugging info for displaced stepping.
1516 maint set internal-error
1517 maint show internal-error
1518 Control what GDB does when an internal error is detected.
1520 maint set internal-warning
1521 maint show internal-warning
1522 Control what GDB does when an internal warning is detected.
1527 Use a wrapper program to launch programs for debugging.
1529 set multiple-symbols (all|ask|cancel)
1530 show multiple-symbols
1531 The value of this variable can be changed to adjust the debugger behavior
1532 when an expression or a breakpoint location contains an ambiguous symbol
1533 name (an overloaded function name, for instance).
1535 set breakpoint always-inserted
1536 show breakpoint always-inserted
1537 Keep breakpoints always inserted in the target, as opposed to inserting
1538 them when resuming the target, and removing them when the target stops.
1539 This option can improve debugger performance on slow remote targets.
1541 set arm fallback-mode (arm|thumb|auto)
1542 show arm fallback-mode
1543 set arm force-mode (arm|thumb|auto)
1545 These commands control how ARM GDB determines whether instructions
1546 are ARM or Thumb. The default for both settings is auto, which uses
1547 the current CPSR value for instructions without symbols; previous
1548 versions of GDB behaved as if "set arm fallback-mode arm".
1550 set disable-randomization
1551 show disable-randomization
1552 Standalone programs run with the virtual address space randomization enabled
1553 by default on some platforms. This option keeps the addresses stable across
1554 multiple debugging sessions.
1558 Control whether other threads are stopped or not when some thread hits
1563 Requests that asynchronous execution is enabled in the target, if available.
1564 In this case, it's possible to resume target in the background, and interact
1565 with GDB while the target is running. "show target-async" displays the
1566 current state of asynchronous execution of the target.
1568 set target-wide-charset
1569 show target-wide-charset
1570 The target-wide-charset is the name of the character set that GDB
1571 uses when printing characters whose type is wchar_t.
1573 set tcp auto-retry (on|off)
1575 set tcp connect-timeout
1576 show tcp connect-timeout
1577 These commands allow GDB to retry failed TCP connections to a remote stub
1578 with a specified timeout period; this is useful if the stub is launched
1579 in parallel with GDB but may not be ready to accept connections immediately.
1581 set libthread-db-search-path
1582 show libthread-db-search-path
1583 Control list of directories which GDB will search for appropriate
1586 set schedule-multiple (on|off)
1587 show schedule-multiple
1588 Allow GDB to resume all threads of all processes or only threads of
1589 the current process.
1593 Use more aggressive caching for accesses to the stack. This improves
1594 performance of remote debugging (particularly backtraces) without
1595 affecting correctness.
1597 set interactive-mode (on|off|auto)
1598 show interactive-mode
1599 Control whether GDB runs in interactive mode (on) or not (off).
1600 When in interactive mode, GDB waits for the user to answer all
1601 queries. Otherwise, GDB does not wait and assumes the default
1602 answer. When set to auto (the default), GDB determines which
1603 mode to use based on the stdin settings.
1608 For program forks, this is replaced by the new more generic `info
1609 inferiors' command. To list checkpoints, you can still use the
1610 `info checkpoints' command, which was an alias for the `info forks'
1614 Replaced by the new `inferior' command. To switch between
1615 checkpoints, you can still use the `restart' command, which was an
1616 alias for the `fork' command.
1619 This is removed, since some targets don't have a notion of
1620 processes. To switch between processes, you can still use the
1621 `inferior' command using GDB's own inferior number.
1624 For program forks, this is replaced by the new more generic `kill
1625 inferior' command. To delete a checkpoint, you can still use the
1626 `delete checkpoint' command, which was an alias for the `delete
1630 For program forks, this is replaced by the new more generic `detach
1631 inferior' command. To detach a checkpoint, you can still use the
1632 `detach checkpoint' command, which was an alias for the `detach
1635 * New native configurations
1637 x86/x86_64 Darwin i[34567]86-*-darwin*
1639 x86_64 MinGW x86_64-*-mingw*
1643 Lattice Mico32 lm32-*
1644 x86 DICOS i[34567]86-*-dicos*
1645 x86_64 DICOS x86_64-*-dicos*
1648 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1649 (mingw32ce) debugging.
1655 These commands were actually not implemented on any target.
1657 *** Changes in GDB 6.8
1659 * New native configurations
1661 NetBSD/hppa hppa*-*netbsd*
1662 Xtensa GNU/Linux xtensa*-*-linux*
1666 NetBSD/hppa hppa*-*-netbsd*
1667 Xtensa GNU/Lunux xtensa*-*-linux*
1669 * Change in command line behavior -- corefiles vs. process ids.
1671 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1672 attaching to process NUMBER fails, GDB no longer attempts to open a
1673 core file named NUMBER. Attaching to a program using the -c option
1674 is no longer supported. Instead, use the '-p' or '--pid' options.
1676 * GDB can now be built as a native debugger for debugging Windows x86
1677 (mingw32) Portable Executable (PE) programs.
1679 * Pending breakpoints no longer change their number when their address
1682 * GDB now supports breakpoints with multiple locations,
1683 including breakpoints on C++ constructors, inside C++ templates,
1684 and in inlined functions.
1686 * GDB's ability to debug optimized code has been improved. GDB more
1687 accurately identifies function bodies and lexical blocks that occupy
1688 more than one contiguous range of addresses.
1690 * Target descriptions can now describe registers for PowerPC.
1692 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1693 registers on PowerPC targets.
1695 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1696 targets even when the libthread_db library is not available.
1698 * The GDB remote stub, gdbserver, now supports the new file transfer
1699 commands (remote put, remote get, and remote delete).
1701 * The GDB remote stub, gdbserver, now supports run and attach in
1702 extended-remote mode.
1704 * hppa*64*-*-hpux11* target broken
1705 The debugger is unable to start a program and fails with the following
1706 error: "Error trying to get information about dynamic linker".
1707 The gdb-6.7 release is also affected.
1709 * GDB now supports the --enable-targets= configure option to allow
1710 building a single GDB executable that supports multiple remote
1711 target architectures.
1713 * GDB now supports debugging C and C++ programs which use the
1714 Decimal Floating Point extension. In addition, the PowerPC target
1715 now has a set of pseudo-registers to inspect decimal float values
1716 stored in two consecutive float registers.
1718 * The -break-insert MI command can optionally create pending
1721 * Improved support for debugging Ada
1722 Many improvements to the Ada language support have been made. These
1724 - Better support for Ada2005 interface types
1725 - Improved handling of arrays and slices in general
1726 - Better support for Taft-amendment types
1727 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1729 - Improved command completion in Ada
1732 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1737 set print frame-arguments (all|scalars|none)
1738 show print frame-arguments
1739 The value of this variable can be changed to control which argument
1740 values should be printed by the debugger when displaying a frame.
1745 Transfer files to and from a remote target, and delete remote files.
1752 Transfer files to and from a remote target, and delete remote files.
1754 * New remote packets
1761 Open, close, read, write, and delete files on the remote system.
1764 Attach to an existing process on the remote system, in extended-remote
1768 Run a new process on the remote system, in extended-remote mode.
1770 *** Changes in GDB 6.7
1772 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1773 bfd, libiberty and opcodes, as revealed by static analysis donated by
1774 Coverity, Inc. (http://scan.coverity.com).
1776 * When looking up multiply-defined global symbols, GDB will now prefer the
1777 symbol definition in the current shared library if it was built using the
1778 -Bsymbolic linker option.
1780 * When the Text User Interface (TUI) is not configured, GDB will now
1781 recognize the -tui command-line option and print a message that the TUI
1784 * The GDB remote stub, gdbserver, now has lower overhead for high
1785 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1787 * GDB for MIPS targets now autodetects whether a remote target provides
1788 32-bit or 64-bit register values.
1790 * Support for C++ member pointers has been improved.
1792 * GDB now understands XML target descriptions, which specify the
1793 target's overall architecture. GDB can read a description from
1794 a local file or over the remote serial protocol.
1796 * Vectors of single-byte data use a new integer type which is not
1797 automatically displayed as character or string data.
1799 * The /s format now works with the print command. It displays
1800 arrays of single-byte integers and pointers to single-byte integers
1803 * Target descriptions can now describe target-specific registers,
1804 for architectures which have implemented the support (currently
1805 only ARM, M68K, and MIPS).
1807 * GDB and the GDB remote stub, gdbserver, now support the XScale
1810 * The GDB remote stub, gdbserver, has been updated to support
1811 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1812 has been rewritten to use the standard GDB remote protocol.
1814 * GDB can now step into C++ functions which are called through thunks.
1816 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1818 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1819 layout. It also supports a TextSeg= and DataSeg= response when only
1820 segment base addresses (rather than offsets) are available.
1822 * The /i format now outputs any trailing branch delay slot instructions
1823 immediately following the last instruction within the count specified.
1825 * The GDB remote protocol "T" stop reply packet now supports a
1826 "library" response. Combined with the new "qXfer:libraries:read"
1827 packet, this response allows GDB to debug shared libraries on targets
1828 where the operating system manages the list of loaded libraries (e.g.
1829 Windows and SymbianOS).
1831 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1832 (DLLs) on Windows and Windows CE targets.
1834 * GDB now supports a faster verification that a .debug file matches its binary
1835 according to its build-id signature, if the signature is present.
1841 Enable or disable hardware flow control (RTS/CTS) on the serial port
1842 when debugging using remote targets.
1844 set mem inaccessible-by-default
1845 show mem inaccessible-by-default
1846 If the target supplies a memory map, for instance via the remote
1847 protocol's "qXfer:memory-map:read" packet, setting this variable
1848 prevents GDB from accessing memory outside the memory map. This
1849 is useful for targets with memory mapped registers or which react
1850 badly to accesses of unmapped address space.
1852 set breakpoint auto-hw
1853 show breakpoint auto-hw
1854 If the target supplies a memory map, for instance via the remote
1855 protocol's "qXfer:memory-map:read" packet, setting this variable
1856 lets GDB use hardware breakpoints automatically for memory regions
1857 where it can not use software breakpoints. This covers both the
1858 "break" command and internal breakpoints used for other commands
1859 including "next" and "finish".
1862 catch exception unhandled
1863 Stop the program execution when Ada exceptions are raised.
1866 Stop the program execution when an Ada assertion failed.
1870 Set an alternate system root for target files. This is a more
1871 general version of "set solib-absolute-prefix", which is now
1872 an alias to "set sysroot".
1875 Provide extended SPU facility status information. This set of
1876 commands is available only when debugging the Cell/B.E. SPU
1879 * New native configurations
1881 OpenBSD/sh sh*-*openbsd*
1884 unset tdesc filename
1886 Use the specified local file as an XML target description, and do
1887 not query the target for its built-in description.
1891 OpenBSD/sh sh*-*-openbsd*
1892 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1893 Toshiba Media Processor mep-elf
1895 * New remote packets
1898 Ignore the specified signals; pass them directly to the debugged program
1899 without stopping other threads or reporting them to GDB.
1901 qXfer:features:read:
1902 Read an XML target description from the target, which describes its
1907 Read or write contents of an spufs file on the target system. These
1908 packets are available only on the Cell/B.E. SPU architecture.
1910 qXfer:libraries:read:
1911 Report the loaded shared libraries. Combined with new "T" packet
1912 response, this packet allows GDB to debug shared libraries on
1913 targets where the operating system manages the list of loaded
1914 libraries (e.g. Windows and SymbianOS).
1918 Support for these obsolete configurations has been removed.
1926 i[34567]86-*-lynxos*
1927 i[34567]86-*-netware*
1928 i[34567]86-*-sco3.2v5*
1929 i[34567]86-*-sco3.2v4*
1931 i[34567]86-*-sysv4.2*
1934 i[34567]86-*-unixware2*
1935 i[34567]86-*-unixware*
1944 * Other removed features
1951 Various m68k-only ROM monitors.
1958 Various Renesas ROM monitors and debugging interfaces for SH and
1963 Support for a Macraigor serial interface to on-chip debugging.
1964 GDB does not directly support the newer parallel or USB
1969 A debug information format. The predecessor to DWARF 2 and
1970 DWARF 3, which are still supported.
1972 Support for the HP aCC compiler on HP-UX/PA-RISC
1974 SOM-encapsulated symbolic debugging information, automatic
1975 invocation of pxdb, and the aCC custom C++ ABI. This does not
1976 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1977 with aCC can still be debugged on an assembly level.
1979 MIPS ".pdr" sections
1981 A MIPS-specific format used to describe stack frame layout
1982 in debugging information.
1986 GDB could work with an older version of Guile to debug
1987 the interpreter and Scheme programs running in it.
1989 set mips stack-arg-size
1990 set mips saved-gpreg-size
1992 Use "set mips abi" to control parameter passing for MIPS.
1994 *** Changes in GDB 6.6
1999 Cell Broadband Engine SPU spu-elf
2001 * GDB can now be configured as a cross-debugger targeting native Windows
2002 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2003 running on a Windows system over TCP/IP to debug Windows programs.
2005 * The GDB remote stub, gdbserver, has been updated to support Windows and
2006 Cygwin debugging. Both single-threaded and multi-threaded programs are
2009 * The "set trust-readonly-sections" command works again. This command was
2010 broken in GDB 6.3, 6.4, and 6.5.
2012 * The "load" command now supports writing to flash memory, if the remote
2013 stub provides the required support.
2015 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2016 longer requires symbolic debug information (e.g. DWARF-2).
2021 unset substitute-path
2022 show substitute-path
2023 Manage a list of substitution rules that GDB uses to rewrite the name
2024 of the directories where the sources are located. This can be useful
2025 for instance when the sources were moved to a different location
2026 between compilation and debugging.
2030 Print each CLI command as it is executed. Each command is prefixed with
2031 a number of `+' symbols representing the nesting depth.
2032 The source command now has a `-v' option to enable the same feature.
2036 The ARM Demon monitor support (RDP protocol, "target rdp").
2038 Kernel Object Display, an embedded debugging feature which only worked with
2039 an obsolete version of Cisco IOS.
2041 The 'set download-write-size' and 'show download-write-size' commands.
2043 * New remote packets
2046 Tell a stub about GDB client features, and request remote target features.
2047 The first feature implemented is PacketSize, which allows the target to
2048 specify the size of packets it can handle - to minimize the number of
2049 packets required and improve performance when connected to a remote
2053 Fetch an OS auxilliary vector from the remote stub. This packet is a
2054 more efficient replacement for qPart:auxv:read.
2056 qXfer:memory-map:read:
2057 Fetch a memory map from the remote stub, including information about
2058 RAM, ROM, and flash memory devices.
2063 Erase and program a flash memory device.
2065 * Removed remote packets
2068 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2069 used it, and only gdbserver implemented it.
2071 *** Changes in GDB 6.5
2075 Renesas M32C/M16C m32c-elf
2077 Morpho Technologies ms1 ms1-elf
2081 init-if-undefined Initialize a convenience variable, but
2082 only if it doesn't already have a value.
2084 The following commands are presently only implemented for native GNU/Linux:
2086 checkpoint Save a snapshot of the program state.
2088 restart <n> Return the program state to a
2089 previously saved state.
2091 info checkpoints List currently saved checkpoints.
2093 delete-checkpoint <n> Delete a previously saved checkpoint.
2095 set|show detach-on-fork Tell gdb whether to detach from a newly
2096 forked process, or to keep debugging it.
2098 info forks List forks of the user program that
2099 are available to be debugged.
2101 fork <n> Switch to debugging one of several
2102 forks of the user program that are
2103 available to be debugged.
2105 delete-fork <n> Delete a fork from the list of forks
2106 that are available to be debugged (and
2107 kill the forked process).
2109 detach-fork <n> Delete a fork from the list of forks
2110 that are available to be debugged (and
2111 allow the process to continue).
2115 Morpho Technologies ms2 ms1-elf
2117 * Improved Windows host support
2119 GDB now builds as a cross debugger hosted on i686-mingw32, including
2120 native console support, and remote communications using either
2121 network sockets or serial ports.
2123 * Improved Modula-2 language support
2125 GDB can now print most types in the Modula-2 syntax. This includes:
2126 basic types, set types, record types, enumerated types, range types,
2127 pointer types and ARRAY types. Procedure var parameters are correctly
2128 printed and hexadecimal addresses and character constants are also
2129 written in the Modula-2 syntax. Best results can be obtained by using
2130 GNU Modula-2 together with the -gdwarf-2 command line option.
2134 The ARM rdi-share module.
2136 The Netware NLM debug server.
2138 *** Changes in GDB 6.4
2140 * New native configurations
2142 OpenBSD/arm arm*-*-openbsd*
2143 OpenBSD/mips64 mips64-*-openbsd*
2147 Morpho Technologies ms1 ms1-elf
2149 * New command line options
2151 --batch-silent As for --batch, but totally silent.
2152 --return-child-result The debugger will exist with the same value
2153 the child (debugged) program exited with.
2154 --eval-command COMMAND, -ex COMMAND
2155 Execute a single GDB CLI command. This may be
2156 specified multiple times and in conjunction
2157 with the --command (-x) option.
2159 * Deprecated commands removed
2161 The following commands, that were deprecated in 2000, have been
2165 set|show arm disassembly-flavor set|show arm disassembler
2166 othernames set arm disassembler
2167 set|show remotedebug set|show debug remote
2168 set|show archdebug set|show debug arch
2169 set|show eventdebug set|show debug event
2172 * New BSD user-level threads support
2174 It is now possible to debug programs using the user-level threads
2175 library on OpenBSD and FreeBSD. Currently supported (target)
2178 FreeBSD/amd64 x86_64-*-freebsd*
2179 FreeBSD/i386 i386-*-freebsd*
2180 OpenBSD/i386 i386-*-openbsd*
2182 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2183 are not yet supported.
2185 * New support for Matsushita MN10300 w/sim added
2186 (Work in progress). mn10300-elf.
2188 * REMOVED configurations and files
2190 VxWorks and the XDR protocol *-*-vxworks
2191 Motorola MCORE mcore-*-*
2192 National Semiconductor NS32000 ns32k-*-*
2194 * New "set print array-indexes" command
2196 After turning this setting "on", GDB prints the index of each element
2197 when displaying arrays. The default is "off" to preserve the previous
2200 * VAX floating point support
2202 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2204 * User-defined command support
2206 In addition to using $arg0..$arg9 for argument passing, it is now possible
2207 to use $argc to determine now many arguments have been passed. See the
2208 section on user-defined commands in the user manual for more information.
2210 *** Changes in GDB 6.3:
2212 * New command line option
2214 GDB now accepts -l followed by a number to set the timeout for remote
2217 * GDB works with GCC -feliminate-dwarf2-dups
2219 GDB now supports a more compact representation of DWARF-2 debug
2220 information using DW_FORM_ref_addr references. These are produced
2221 by GCC with the option -feliminate-dwarf2-dups and also by some
2222 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2223 to use -feliminate-dwarf2-dups.
2225 * Internationalization
2227 When supported by the host system, GDB will be built with
2228 internationalization (libintl). The task of marking up the sources is
2229 continued, we're looking forward to our first translation.
2233 Initial support for debugging programs compiled with the GNAT
2234 implementation of the Ada programming language has been integrated
2235 into GDB. In this release, support is limited to expression evaluation.
2237 * New native configurations
2239 GNU/Linux/m32r m32r-*-linux-gnu
2243 GDB's remote protocol now includes support for the 'p' packet. This
2244 packet is used to fetch individual registers from a remote inferior.
2246 * END-OF-LIFE registers[] compatibility module
2248 GDB's internal register infrastructure has been completely rewritten.
2249 The new infrastructure making possible the implementation of key new
2250 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2253 GDB 6.3 will be the last release to include the the registers[]
2254 compatibility module that allowed out-of-date configurations to
2255 continue to work. This change directly impacts the following
2265 powerpc bdm protocol
2267 Unless there is activity to revive these configurations, they will be
2268 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2270 * OBSOLETE configurations and files
2272 Configurations that have been declared obsolete in this release have
2273 been commented out. Unless there is activity to revive these
2274 configurations, the next release of GDB will have their sources
2275 permanently REMOVED.
2284 *** Changes in GDB 6.2.1:
2286 * MIPS `break main; run' gave an heuristic-fence-post warning
2288 When attempting to run even a simple program, a warning about
2289 heuristic-fence-post being hit would be reported. This problem has
2292 * MIPS IRIX 'long double' crashed GDB
2294 When examining a long double variable, GDB would get a segmentation
2295 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2296 IRIX long double values).
2300 A bug in the VAX stack code was causing problems with the "next"
2301 command. This problem has been fixed.
2303 *** Changes in GDB 6.2:
2305 * Fix for ``many threads''
2307 On GNU/Linux systems that use the NPTL threads library, a program
2308 rapidly creating and deleting threads would confuse GDB leading to the
2311 ptrace: No such process.
2312 thread_db_get_info: cannot get thread info: generic error
2314 This problem has been fixed.
2316 * "-async" and "-noasync" options removed.
2318 Support for the broken "-noasync" option has been removed (it caused
2321 * New ``start'' command.
2323 This command runs the program until the begining of the main procedure.
2325 * New BSD Kernel Data Access Library (libkvm) interface
2327 Using ``target kvm'' it is now possible to debug kernel core dumps and
2328 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2329 platforms. Currently supported (native-only) configurations are:
2331 FreeBSD/amd64 x86_64-*-freebsd*
2332 FreeBSD/i386 i?86-*-freebsd*
2333 NetBSD/i386 i?86-*-netbsd*
2334 NetBSD/m68k m68*-*-netbsd*
2335 NetBSD/sparc sparc-*-netbsd*
2336 OpenBSD/amd64 x86_64-*-openbsd*
2337 OpenBSD/i386 i?86-*-openbsd*
2338 OpenBSD/m68k m68*-openbsd*
2339 OpenBSD/sparc sparc-*-openbsd*
2341 * Signal trampoline code overhauled
2343 Many generic problems with GDB's signal handling code have been fixed.
2344 These include: backtraces through non-contiguous stacks; recognition
2345 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2346 call; backtrace through a signal trampoline; step into and out of
2347 signal handlers; and single-stepping in the signal trampoline.
2349 Please note that kernel bugs are a limiting factor here. These
2350 features have been shown to work on an s390 GNU/Linux system that
2351 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2353 * Cygwin support for DWARF 2 added.
2355 * New native configurations
2357 GNU/Linux/hppa hppa*-*-linux*
2358 OpenBSD/hppa hppa*-*-openbsd*
2359 OpenBSD/m68k m68*-*-openbsd*
2360 OpenBSD/m88k m88*-*-openbsd*
2361 OpenBSD/powerpc powerpc-*-openbsd*
2362 NetBSD/vax vax-*-netbsd*
2363 OpenBSD/vax vax-*-openbsd*
2365 * END-OF-LIFE frame compatibility module
2367 GDB's internal frame infrastructure has been completely rewritten.
2368 The new infrastructure making it possible to support key new features
2369 including DWARF 2 Call Frame Information. To aid in the task of
2370 migrating old configurations to this new infrastructure, a
2371 compatibility module, that allowed old configurations to continue to
2372 work, was also included.
2374 GDB 6.2 will be the last release to include this frame compatibility
2375 module. This change directly impacts the following configurations:
2385 Unless there is activity to revive these configurations, they will be
2386 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2388 * REMOVED configurations and files
2390 Sun 3, running SunOS 3 m68*-*-sunos3*
2391 Sun 3, running SunOS 4 m68*-*-sunos4*
2392 Sun 2, running SunOS 3 m68000-*-sunos3*
2393 Sun 2, running SunOS 4 m68000-*-sunos4*
2394 Motorola 680x0 running LynxOS m68*-*-lynxos*
2395 AT&T 3b1/Unix pc m68*-att-*
2396 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2397 decstation mips-dec-* mips-little-*
2398 riscos mips-*-riscos* mips-*-sysv*
2399 sonymips mips-sony-*
2400 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2402 *** Changes in GDB 6.1.1:
2404 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2406 The TUI (Text-mode User Interface) is now built as part of a default
2407 GDB configuration. It is enabled by either selecting the TUI with the
2408 command line option "-i=tui" or by running the separate "gdbtui"
2409 program. For more information on the TUI, see the manual "Debugging
2412 * Pending breakpoint support (also included in GDB 6.1)
2414 Support has been added to allow you to specify breakpoints in shared
2415 libraries that have not yet been loaded. If a breakpoint location
2416 cannot be found, and the "breakpoint pending" option is set to auto,
2417 GDB queries you if you wish to make the breakpoint pending on a future
2418 shared-library load. If and when GDB resolves the breakpoint symbol,
2419 the pending breakpoint is removed as one or more regular breakpoints
2422 Pending breakpoints are very useful for GCJ Java debugging.
2424 * Fixed ISO-C build problems
2426 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2427 non ISO-C code that stopped them being built using a more strict ISO-C
2428 compiler (e.g., IBM's C compiler).
2430 * Fixed build problem on IRIX 5
2432 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2433 wasn't able to compile compile on an IRIX 5 system.
2435 * Added execute permission to gdb/gdbserver/configure
2437 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2438 permission. This bug would cause configure to fail on a number of
2439 systems (Solaris, IRIX). Ref: server/519.
2441 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2443 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2444 has been updated to use constant array sizes.
2446 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2448 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2449 its generated DWARF Call Frame Info. This encoding was causing GDB to
2450 panic, that panic has been fixed. Ref: gdb/1628.
2452 * Fixed a problem when examining parameters in shared library code.
2454 When examining parameters in optimized shared library code generated
2455 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2456 not available''. GDB now correctly displays the variable's value.
2458 *** Changes in GDB 6.1:
2460 * Removed --with-mmalloc
2462 Support for the mmalloc memory manager has been removed, as it
2463 conflicted with the internal gdb byte cache.
2465 * Changes in AMD64 configurations
2467 The AMD64 target now includes the %cs and %ss registers. As a result
2468 the AMD64 remote protocol has changed; this affects the floating-point
2469 and SSE registers. If you rely on those registers for your debugging,
2470 you should upgrade gdbserver on the remote side.
2472 * Revised SPARC target
2474 The SPARC target has been completely revised, incorporating the
2475 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2476 support for LynxOS and SunOS 4 has been dropped. Calling functions
2477 from within GDB on operating systems with a non-executable stack
2478 (Solaris, OpenBSD) now works.
2482 GDB has a new C++ demangler which does a better job on the mangled
2483 names generated by current versions of g++. It also runs faster, so
2484 with this and other changes gdb should now start faster on large C++
2487 * DWARF 2 Location Expressions
2489 GDB support for location expressions has been extended to support function
2490 arguments and frame bases. Older versions of GDB could crash when they
2493 * C++ nested types and namespaces
2495 GDB's support for nested types and namespaces in C++ has been
2496 improved, especially if you use the DWARF 2 debugging format. (This
2497 is the default for recent versions of GCC on most platforms.)
2498 Specifically, if you have a class "Inner" defined within a class or
2499 namespace "Outer", then GDB realizes that the class's name is
2500 "Outer::Inner", not simply "Inner". This should greatly reduce the
2501 frequency of complaints about not finding RTTI symbols. In addition,
2502 if you are stopped at inside of a function defined within a namespace,
2503 GDB modifies its name lookup accordingly.
2505 * New native configurations
2507 NetBSD/amd64 x86_64-*-netbsd*
2508 OpenBSD/amd64 x86_64-*-openbsd*
2509 OpenBSD/alpha alpha*-*-openbsd*
2510 OpenBSD/sparc sparc-*-openbsd*
2511 OpenBSD/sparc64 sparc64-*-openbsd*
2513 * New debugging protocols
2515 M32R with SDI protocol m32r-*-elf*
2517 * "set prompt-escape-char" command deleted.
2519 The command "set prompt-escape-char" has been deleted. This command,
2520 and its very obscure effet on GDB's prompt, was never documented,
2521 tested, nor mentioned in the NEWS file.
2523 * OBSOLETE configurations and files
2525 Configurations that have been declared obsolete in this release have
2526 been commented out. Unless there is activity to revive these
2527 configurations, the next release of GDB will have their sources
2528 permanently REMOVED.
2530 Sun 3, running SunOS 3 m68*-*-sunos3*
2531 Sun 3, running SunOS 4 m68*-*-sunos4*
2532 Sun 2, running SunOS 3 m68000-*-sunos3*
2533 Sun 2, running SunOS 4 m68000-*-sunos4*
2534 Motorola 680x0 running LynxOS m68*-*-lynxos*
2535 AT&T 3b1/Unix pc m68*-att-*
2536 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2537 decstation mips-dec-* mips-little-*
2538 riscos mips-*-riscos* mips-*-sysv*
2539 sonymips mips-sony-*
2540 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2542 * REMOVED configurations and files
2544 SGI Irix-4.x mips-sgi-irix4 or iris4
2545 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2546 Z8000 simulator z8k-zilog-none or z8ksim
2547 Matsushita MN10200 w/simulator mn10200-*-*
2548 H8/500 simulator h8500-hitachi-hms or h8500hms
2549 HP/PA running BSD hppa*-*-bsd*
2550 HP/PA running OSF/1 hppa*-*-osf*
2551 HP/PA Pro target hppa*-*-pro*
2552 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2553 386BSD i[3456]86-*-bsd*
2554 Sequent family i[3456]86-sequent-sysv4*
2555 i[3456]86-sequent-sysv*
2556 i[3456]86-sequent-bsd*
2557 SPARC running LynxOS sparc-*-lynxos*
2558 SPARC running SunOS 4 sparc-*-sunos4*
2559 Tsqware Sparclet sparclet-*-*
2560 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2562 *** Changes in GDB 6.0:
2566 Support for debugging the Objective-C programming language has been
2567 integrated into GDB.
2569 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2571 DWARF 2's Call Frame Information makes available compiler generated
2572 information that more exactly describes the program's run-time stack.
2573 By using this information, GDB is able to provide more robust stack
2576 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2577 have been updated to use a new backtrace mechanism which includes
2578 DWARF 2 CFI support.
2582 GDB's remote protocol has been extended to include support for hosted
2583 file I/O (where the remote target uses GDB's file system). See GDB's
2584 remote protocol documentation for details.
2586 * All targets using the new architecture framework.
2588 All of GDB's targets have been updated to use the new internal
2589 architecture framework. The way is now open for future GDB releases
2590 to include cross-architecture native debugging support (i386 on amd64,
2593 * GNU/Linux's Thread Local Storage (TLS)
2595 GDB now includes support for for the GNU/Linux implementation of
2596 per-thread variables.
2598 * GNU/Linux's Native POSIX Thread Library (NPTL)
2600 GDB's thread code has been updated to work with either the new
2601 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2603 * Separate debug info.
2605 GDB, in conjunction with BINUTILS, now supports a mechanism for
2606 automatically loading debug information from a separate file. Instead
2607 of shipping full debug and non-debug versions of system libraries,
2608 system integrators can now instead ship just the stripped libraries
2609 and optional debug files.
2611 * DWARF 2 Location Expressions
2613 DWARF 2 Location Expressions allow the compiler to more completely
2614 describe the location of variables (even in optimized code) to the
2617 GDB now includes preliminary support for location expressions (support
2618 for DW_OP_piece is still missing).
2622 A number of long standing bugs that caused GDB to die while starting a
2623 Java application have been fixed. GDB's Java support is now
2624 considered "useable".
2626 * GNU/Linux support for fork, vfork, and exec.
2628 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2629 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2632 * GDB supports logging output to a file
2634 There are two new commands, "set logging" and "show logging", which can be
2635 used to capture GDB's output to a file.
2637 * The meaning of "detach" has changed for gdbserver
2639 The "detach" command will now resume the application, as documented. To
2640 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2643 * d10v, m68hc11 `regs' command deprecated
2645 The `info registers' command has been updated so that it displays the
2646 registers using a format identical to the old `regs' command.
2650 A new command, "maint set profile on/off", has been added. This command can
2651 be used to enable or disable profiling while running GDB, to profile a
2652 session or a set of commands. In addition there is a new configure switch,
2653 "--enable-profiling", which will cause GDB to be compiled with profiling
2654 data, for more informative profiling results.
2656 * Default MI syntax changed to "mi2".
2658 The default MI (machine interface) syntax, enabled by the command line
2659 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2660 "mi1", can be enabled by specifying the option "-i=mi1".
2662 Support for the original "mi0" syntax (included in GDB 5.0) has been
2665 Fix for gdb/192: removed extraneous space when displaying frame level.
2666 Fix for gdb/672: update changelist is now output in mi list format.
2667 Fix for gdb/702: a -var-assign that updates the value now shows up
2668 in a subsequent -var-update.
2670 * New native configurations.
2672 FreeBSD/amd64 x86_64-*-freebsd*
2674 * Multi-arched targets.
2676 HP/PA HPUX11 hppa*-*-hpux*
2677 Renesas M32R/D w/simulator m32r-*-elf*
2679 * OBSOLETE configurations and files
2681 Configurations that have been declared obsolete in this release have
2682 been commented out. Unless there is activity to revive these
2683 configurations, the next release of GDB will have their sources
2684 permanently REMOVED.
2686 Z8000 simulator z8k-zilog-none or z8ksim
2687 Matsushita MN10200 w/simulator mn10200-*-*
2688 H8/500 simulator h8500-hitachi-hms or h8500hms
2689 HP/PA running BSD hppa*-*-bsd*
2690 HP/PA running OSF/1 hppa*-*-osf*
2691 HP/PA Pro target hppa*-*-pro*
2692 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2693 Sequent family i[3456]86-sequent-sysv4*
2694 i[3456]86-sequent-sysv*
2695 i[3456]86-sequent-bsd*
2696 Tsqware Sparclet sparclet-*-*
2697 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2699 * REMOVED configurations and files
2702 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2703 IBM AIX PS/2 i[3456]86-*-aix
2704 i386 running Mach 3.0 i[3456]86-*-mach3*
2705 i386 running Mach i[3456]86-*-mach*
2706 i386 running OSF/1 i[3456]86-*osf1mk*
2707 HP/Apollo 68k Family m68*-apollo*-sysv*,
2709 m68*-hp-bsd*, m68*-hp-hpux*
2710 Argonaut Risc Chip (ARC) arc-*-*
2711 Mitsubishi D30V d30v-*-*
2712 Fujitsu FR30 fr30-*-elf*
2713 OS/9000 i[34]86-*-os9k
2714 I960 with MON960 i960-*-coff
2716 * MIPS $fp behavior changed
2718 The convenience variable $fp, for the MIPS, now consistently returns
2719 the address of the current frame's base. Previously, depending on the
2720 context, $fp could refer to either $sp or the current frame's base
2721 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2722 The GNU Source-Level Debugger''.
2724 *** Changes in GDB 5.3:
2726 * GNU/Linux shared library multi-threaded performance improved.
2728 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2729 `/proc', in preference to `ptrace' for memory reads. This may result
2730 in an improvement in the start-up time of multi-threaded, shared
2731 library applications when run under GDB. One GDB user writes: ``loads
2732 shared libs like mad''.
2734 * ``gdbserver'' now supports multi-threaded applications on some targets
2736 Support for debugging multi-threaded applications which use
2737 the GNU/Linux LinuxThreads package has been added for
2738 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2739 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2741 * GDB now supports C/C++ preprocessor macros.
2743 GDB now expands preprocessor macro invocations in C/C++ expressions,
2744 and provides various commands for showing macro definitions and how
2747 The new command `macro expand EXPRESSION' expands any macro
2748 invocations in expression, and shows the result.
2750 The new command `show macro MACRO-NAME' shows the definition of the
2751 macro named MACRO-NAME, and where it was defined.
2753 Most compilers don't include information about macros in the debugging
2754 information by default. In GCC 3.1, for example, you need to compile
2755 your program with the options `-gdwarf-2 -g3'. If the macro
2756 information is present in the executable, GDB will read it.
2758 * Multi-arched targets.
2760 DEC Alpha (partial) alpha*-*-*
2761 DEC VAX (partial) vax-*-*
2763 National Semiconductor NS32000 (partial) ns32k-*-*
2764 Motorola 68000 (partial) m68k-*-*
2765 Motorola MCORE mcore-*-*
2769 Fujitsu FRV architecture added by Red Hat frv*-*-*
2772 * New native configurations
2774 Alpha NetBSD alpha*-*-netbsd*
2775 SH NetBSD sh*-*-netbsdelf*
2776 MIPS NetBSD mips*-*-netbsd*
2777 UltraSPARC NetBSD sparc64-*-netbsd*
2779 * OBSOLETE configurations and files
2781 Configurations that have been declared obsolete in this release have
2782 been commented out. Unless there is activity to revive these
2783 configurations, the next release of GDB will have their sources
2784 permanently REMOVED.
2786 Mitsubishi D30V d30v-*-*
2787 OS/9000 i[34]86-*-os9k
2788 IBM AIX PS/2 i[3456]86-*-aix
2789 Fujitsu FR30 fr30-*-elf*
2790 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2791 Argonaut Risc Chip (ARC) arc-*-*
2792 i386 running Mach 3.0 i[3456]86-*-mach3*
2793 i386 running Mach i[3456]86-*-mach*
2794 i386 running OSF/1 i[3456]86-*osf1mk*
2795 HP/Apollo 68k Family m68*-apollo*-sysv*,
2797 m68*-hp-bsd*, m68*-hp-hpux*
2798 I960 with MON960 i960-*-coff
2800 * OBSOLETE languages
2802 CHILL, a Pascal like language used by telecommunications companies.
2804 * REMOVED configurations and files
2806 AMD 29k family via UDI a29k-amd-udi, udi29k
2807 A29K VxWorks a29k-*-vxworks
2808 AMD 29000 embedded, using EBMON a29k-none-none
2809 AMD 29000 embedded with COFF a29k-none-coff
2810 AMD 29000 embedded with a.out a29k-none-aout
2812 testsuite/gdb.hp/gdb.threads-hp/ directory
2814 * New command "set max-user-call-depth <nnn>"
2816 This command allows the user to limit the call depth of user-defined
2817 commands. The default is 1024.
2819 * Changes in FreeBSD/i386 native debugging.
2821 Support for the "generate-core-file" has been added.
2823 * New commands "dump", "append", and "restore".
2825 These commands allow data to be copied from target memory
2826 to a bfd-format or binary file (dump and append), and back
2827 from a file into memory (restore).
2829 * Improved "next/step" support on multi-processor Alpha Tru64.
2831 The previous single-step mechanism could cause unpredictable problems,
2832 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2833 of a software single-step mechanism prevents this.
2835 *** Changes in GDB 5.2.1:
2843 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2844 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2845 Fix, by Joel Brobecker imported from mainline.
2847 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2848 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2849 Fix, by Fred Fish, imported from mainline.
2851 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2852 Surprisingly enough, it works now.
2853 By Michal Ludvig, imported from mainline.
2855 i386 hardware watchpoint support:
2856 avoid misses on second run for some targets.
2857 By Pierre Muller, imported from mainline.
2859 *** Changes in GDB 5.2:
2861 * New command "set trust-readonly-sections on[off]".
2863 This command is a hint that tells gdb that read-only sections
2864 really are read-only (ie. that their contents will not change).
2865 In this mode, gdb will go to the object file rather than the
2866 target to read memory from read-only sections (such as ".text").
2867 This can be a significant performance improvement on some
2868 (notably embedded) targets.
2870 * New command "generate-core-file" (or "gcore").
2872 This new gdb command allows the user to drop a core file of the child
2873 process state at any time. So far it's been implemented only for
2874 GNU/Linux and Solaris, but should be relatively easily ported to other
2875 hosts. Argument is core file name (defaults to core.<pid>).
2877 * New command line option
2879 GDB now accepts --pid or -p followed by a process id.
2881 * Change in command line behavior -- corefiles vs. process ids.
2883 There is a subtle behavior in the way in which GDB handles
2884 command line arguments. The first non-flag argument is always
2885 a program to debug, but the second non-flag argument may either
2886 be a corefile or a process id. Previously, GDB would attempt to
2887 open the second argument as a corefile, and if that failed, would
2888 issue a superfluous error message and then attempt to attach it as
2889 a process. Now, if the second argument begins with a non-digit,
2890 it will be treated as a corefile. If it begins with a digit,
2891 GDB will attempt to attach it as a process, and if no such process
2892 is found, will then attempt to open it as a corefile.
2894 * Changes in ARM configurations.
2896 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2897 configuration is fully multi-arch.
2899 * New native configurations
2901 ARM NetBSD arm*-*-netbsd*
2902 x86 OpenBSD i[3456]86-*-openbsd*
2903 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2904 Sparc64 running FreeBSD sparc64-*-freebsd*
2908 Sanyo XStormy16 xstormy16-elf
2910 * OBSOLETE configurations and files
2912 Configurations that have been declared obsolete in this release have
2913 been commented out. Unless there is activity to revive these
2914 configurations, the next release of GDB will have their sources
2915 permanently REMOVED.
2917 AMD 29k family via UDI a29k-amd-udi, udi29k
2918 A29K VxWorks a29k-*-vxworks
2919 AMD 29000 embedded, using EBMON a29k-none-none
2920 AMD 29000 embedded with COFF a29k-none-coff
2921 AMD 29000 embedded with a.out a29k-none-aout
2923 testsuite/gdb.hp/gdb.threads-hp/ directory
2925 * REMOVED configurations and files
2927 TI TMS320C80 tic80-*-*
2929 PowerPC Solaris powerpcle-*-solaris*
2930 PowerPC Windows NT powerpcle-*-cygwin32
2931 PowerPC Netware powerpc-*-netware*
2932 Harris/CXUX m88k m88*-harris-cxux*
2933 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2934 ns32k-utek-sysv* ns32k-utek-*
2935 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2936 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2937 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2938 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2939 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2941 * Changes to command line processing
2943 The new `--args' feature can be used to specify command-line arguments
2944 for the inferior from gdb's command line.
2946 * Changes to key bindings
2948 There is a new `operate-and-get-next' function bound to `C-o'.
2950 *** Changes in GDB 5.1.1
2952 Fix compile problem on DJGPP.
2954 Fix a problem with floating-point registers on the i386 being
2957 Fix to stop GDB crashing on .debug_str debug info.
2959 Numerous documentation fixes.
2961 Numerous testsuite fixes.
2963 *** Changes in GDB 5.1:
2965 * New native configurations
2967 Alpha FreeBSD alpha*-*-freebsd*
2968 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2969 MIPS GNU/Linux mips*-*-linux*
2970 MIPS SGI Irix 6.x mips*-sgi-irix6*
2971 ia64 AIX ia64-*-aix*
2972 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2976 Motorola 68HC11 and 68HC12 m68hc11-elf
2978 UltraSparc running GNU/Linux sparc64-*-linux*
2980 * OBSOLETE configurations and files
2982 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2983 Harris/CXUX m88k m88*-harris-cxux*
2984 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2985 ns32k-utek-sysv* ns32k-utek-*
2986 TI TMS320C80 tic80-*-*
2988 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2989 PowerPC Solaris powerpcle-*-solaris*
2990 PowerPC Windows NT powerpcle-*-cygwin32
2991 PowerPC Netware powerpc-*-netware*
2992 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2993 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2994 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2995 Apple Macintosh (MPW) host N/A
2997 stuff.c (Program to stuff files into a specially prepared space in kdb)
2998 kdb-start.c (Main loop for the standalone kernel debugger)
3000 Configurations that have been declared obsolete in this release have
3001 been commented out. Unless there is activity to revive these
3002 configurations, the next release of GDB will have their sources
3003 permanently REMOVED.
3005 * REMOVED configurations and files
3007 Altos 3068 m68*-altos-*
3008 Convex c1-*-*, c2-*-*
3010 ARM RISCix arm-*-* (as host)
3014 * GDB has been converted to ISO C.
3016 GDB's source code has been converted to ISO C. In particular, the
3017 sources are fully protoized, and rely on standard headers being
3022 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3024 * The MI enabled by default.
3026 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3027 revised and enabled by default. Packages which use GDB as a debugging
3028 engine behind a UI or another front end are encouraged to switch to
3029 using the GDB/MI interface, instead of the old annotations interface
3030 which is now deprecated.
3032 * Support for debugging Pascal programs.
3034 GDB now includes support for debugging Pascal programs. The following
3035 main features are supported:
3037 - Pascal-specific data types such as sets;
3039 - automatic recognition of Pascal sources based on file-name
3042 - Pascal-style display of data types, variables, and functions;
3044 - a Pascal expression parser.
3046 However, some important features are not yet supported.
3048 - Pascal string operations are not supported at all;
3050 - there are some problems with boolean types;
3052 - Pascal type hexadecimal constants are not supported
3053 because they conflict with the internal variables format;
3055 - support for Pascal objects and classes is not full yet;
3057 - unlike Pascal, GDB is case-sensitive for symbol names.
3059 * Changes in completion.
3061 Commands such as `shell', `run' and `set args', which pass arguments
3062 to inferior programs, now complete on file names, similar to what
3063 users expect at the shell prompt.
3065 Commands which accept locations, such as `disassemble', `print',
3066 `breakpoint', `until', etc. now complete on filenames as well as
3067 program symbols. Thus, if you type "break foob TAB", and the source
3068 files linked into the programs include `foobar.c', that file name will
3069 be one of the candidates for completion. However, file names are not
3070 considered for completion after you typed a colon that delimits a file
3071 name from a name of a function in that file, as in "break foo.c:bar".
3073 `set demangle-style' completes on available demangling styles.
3075 * New platform-independent commands:
3077 It is now possible to define a post-hook for a command as well as a
3078 hook that runs before the command. For more details, see the
3079 documentation of `hookpost' in the GDB manual.
3081 * Changes in GNU/Linux native debugging.
3083 Support for debugging multi-threaded programs has been completely
3084 revised for all platforms except m68k and sparc. You can now debug as
3085 many threads as your system allows you to have.
3087 Attach/detach is supported for multi-threaded programs.
3089 Support for SSE registers was added for x86. This doesn't work for
3090 multi-threaded programs though.
3092 * Changes in MIPS configurations.
3094 Multi-arch support is enabled for all MIPS configurations.
3096 GDB can now be built as native debugger on SGI Irix 6.x systems for
3097 debugging n32 executables. (Debugging 64-bit executables is not yet
3100 * Unified support for hardware watchpoints in all x86 configurations.
3102 Most (if not all) native x86 configurations support hardware-assisted
3103 breakpoints and watchpoints in a unified manner. This support
3104 implements debug register sharing between watchpoints, which allows to
3105 put a virtually infinite number of watchpoints on the same address,
3106 and also supports watching regions up to 16 bytes with several debug
3109 The new maintenance command `maintenance show-debug-regs' toggles
3110 debugging print-outs in functions that insert, remove, and test
3111 watchpoints and hardware breakpoints.
3113 * Changes in the DJGPP native configuration.
3115 New command ``info dos sysinfo'' displays assorted information about
3116 the CPU, OS, memory, and DPMI server.
3118 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3119 display information about segment descriptors stored in GDT, LDT, and
3122 New commands ``info dos pde'' and ``info dos pte'' display entries
3123 from Page Directory and Page Tables (for now works with CWSDPMI only).
3124 New command ``info dos address-pte'' displays the Page Table entry for
3125 a given linear address.
3127 GDB can now pass command lines longer than 126 characters to the
3128 program being debugged (requires an update to the libdbg.a library
3129 which is part of the DJGPP development kit).
3131 DWARF2 debug info is now supported.
3133 It is now possible to `step' and `next' through calls to `longjmp'.
3135 * Changes in documentation.
3137 All GDB documentation was converted to GFDL, the GNU Free
3138 Documentation License.
3140 Tracepoints-related commands are now fully documented in the GDB
3143 TUI, the Text-mode User Interface, is now documented in the manual.
3145 Tracepoints-related commands are now fully documented in the GDB
3148 The "GDB Internals" manual now has an index. It also includes
3149 documentation of `ui_out' functions, GDB coding standards, x86
3150 hardware watchpoints, and memory region attributes.
3152 * GDB's version number moved to ``version.in''
3154 The Makefile variable VERSION has been replaced by the file
3155 ``version.in''. People creating GDB distributions should update the
3156 contents of this file.
3160 GUD support is now a standard part of the EMACS distribution.
3162 *** Changes in GDB 5.0:
3164 * Improved support for debugging FP programs on x86 targets
3166 Unified and much-improved support for debugging floating-point
3167 programs on all x86 targets. In particular, ``info float'' now
3168 displays the FP registers in the same format on all x86 targets, with
3169 greater level of detail.
3171 * Improvements and bugfixes in hardware-assisted watchpoints
3173 It is now possible to watch array elements, struct members, and
3174 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3175 on x86 targets no longer erroneously trigger when the address is
3178 * Improvements in the native DJGPP version of GDB
3180 The distribution now includes all the scripts and auxiliary files
3181 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3182 machines ``out of the box''.
3184 The DJGPP version can now debug programs that use signals. It is
3185 possible to catch signals that happened in the debuggee, deliver
3186 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3187 would kill the program being debugged.) Programs that hook hardware
3188 interrupts (keyboard, timer, etc.) can also be debugged.
3190 It is now possible to debug DJGPP programs that redirect their
3191 standard handles or switch them to raw (as opposed to cooked) mode, or
3192 even close them. The command ``run < foo > bar'' works as expected,
3193 and ``info terminal'' reports useful information about the debuggee's
3194 terminal, including raw/cooked mode, redirection, etc.
3196 The DJGPP version now uses termios functions for console I/O, which
3197 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3200 DOS-style file names with drive letters are now fully supported by
3203 It is now possible to debug DJGPP programs that switch their working
3204 directory. It is also possible to rerun the debuggee any number of
3205 times without restarting GDB; thus, you can use the same setup,
3206 breakpoints, etc. for many debugging sessions.
3208 * New native configurations
3210 ARM GNU/Linux arm*-*-linux*
3211 PowerPC GNU/Linux powerpc-*-linux*
3215 Motorola MCore mcore-*-*
3216 x86 VxWorks i[3456]86-*-vxworks*
3217 PowerPC VxWorks powerpc-*-vxworks*
3218 TI TMS320C80 tic80-*-*
3220 * OBSOLETE configurations
3222 Altos 3068 m68*-altos-*
3223 Convex c1-*-*, c2-*-*
3225 ARM RISCix arm-*-* (as host)
3228 Configurations that have been declared obsolete will be commented out,
3229 but the code will be left in place. If there is no activity to revive
3230 these configurations before the next release of GDB, the sources will
3231 be permanently REMOVED.
3233 * Gould support removed
3235 Support for the Gould PowerNode and NP1 has been removed.
3237 * New features for SVR4
3239 On SVR4 native platforms (such as Solaris), if you attach to a process
3240 without first loading a symbol file, GDB will now attempt to locate and
3241 load symbols from the running process's executable file.
3243 * Many C++ enhancements
3245 C++ support has been greatly improved. Overload resolution now works properly
3246 in almost all cases. RTTI support is on the way.
3248 * Remote targets can connect to a sub-program
3250 A popen(3) style serial-device has been added. This device starts a
3251 sub-process (such as a stand-alone simulator) and then communicates
3252 with that. The sub-program to run is specified using the syntax
3253 ``|<program> <args>'' vis:
3255 (gdb) set remotedebug 1
3256 (gdb) target extended-remote |mn10300-elf-sim program-args
3258 * MIPS 64 remote protocol
3260 A long standing bug in the mips64 remote protocol where by GDB
3261 expected certain 32 bit registers (ex SR) to be transfered as 32
3262 instead of 64 bits has been fixed.
3264 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3265 added to provide backward compatibility with older versions of GDB.
3267 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3269 The command ``set remotebinarydownload'' command has been replaced by
3270 ``set remote X-packet''. Other commands in ``set remote'' family
3271 include ``set remote P-packet''.
3273 * Breakpoint commands accept ranges.
3275 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3276 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3277 ``tracepoint passcount'' also accepts a range of tracepoints.
3279 * ``apropos'' command added.
3281 The ``apropos'' command searches through command names and
3282 documentation strings, printing out matches, making it much easier to
3283 try to find a command that does what you are looking for.
3287 A new machine oriented interface (MI) has been added to GDB. This
3288 interface is designed for debug environments running GDB as a separate
3289 process. This is part of the long term libGDB project. See the
3290 "GDB/MI" chapter of the GDB manual for further information. It can be
3291 enabled by configuring with:
3293 .../configure --enable-gdbmi
3295 *** Changes in GDB-4.18:
3297 * New native configurations
3299 HP-UX 10.20 hppa*-*-hpux10.20
3300 HP-UX 11.x hppa*-*-hpux11.0*
3301 M68K GNU/Linux m68*-*-linux*
3305 Fujitsu FR30 fr30-*-elf*
3306 Intel StrongARM strongarm-*-*
3307 Mitsubishi D30V d30v-*-*
3309 * OBSOLETE configurations
3311 Gould PowerNode, NP1 np1-*-*, pn-*-*
3313 Configurations that have been declared obsolete will be commented out,
3314 but the code will be left in place. If there is no activity to revive
3315 these configurations before the next release of GDB, the sources will
3316 be permanently REMOVED.
3320 As a compatibility experiment, GDB's source files buildsym.h and
3321 buildsym.c have been converted to pure standard C, no longer
3322 containing any K&R compatibility code. We believe that all systems in
3323 use today either come with a standard C compiler, or have a GCC port
3324 available. If this is not true, please report the affected
3325 configuration to bug-gdb@gnu.org immediately. See the README file for
3326 information about getting a standard C compiler if you don't have one
3331 GDB now uses readline 2.2.
3333 * set extension-language
3335 You can now control the mapping between filename extensions and source
3336 languages by using the `set extension-language' command. For instance,
3337 you can ask GDB to treat .c files as C++ by saying
3338 set extension-language .c c++
3339 The command `info extensions' lists all of the recognized extensions
3340 and their associated languages.
3342 * Setting processor type for PowerPC and RS/6000
3344 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3345 you can use the `set processor' command to specify what variant of the
3346 PowerPC family you are debugging. The command
3350 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3351 following PowerPC and RS6000 variants:
3353 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3354 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3356 403GC IBM PowerPC 403GC
3357 505 Motorola PowerPC 505
3358 860 Motorola PowerPC 860 or 850
3359 601 Motorola PowerPC 601
3360 602 Motorola PowerPC 602
3361 603 Motorola/IBM PowerPC 603 or 603e
3362 604 Motorola PowerPC 604 or 604e
3363 750 Motorola/IBM PowerPC 750 or 750
3365 At the moment, this command just tells GDB what to name the
3366 special-purpose processor registers. Since almost all the affected
3367 registers are inaccessible to user-level programs, this command is
3368 only useful for remote debugging in its present form.
3372 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3373 more extensive support for HP-UX. Added features include shared
3374 library support, kernel threads and hardware watchpoints for 11.00,
3375 support for HP's ANSI C and C++ compilers, and a compatibility mode
3376 for xdb and dbx commands.
3380 HP's donation includes the new concept of catchpoints, which is a
3381 generalization of the old catch command. On HP-UX, it is now possible
3382 to catch exec, fork, and vfork, as well as library loading.
3384 This means that the existing catch command has changed; its first
3385 argument now specifies the type of catch to be set up. See the
3386 output of "help catch" for a list of catchpoint types.
3388 * Debugging across forks
3390 On HP-UX, you can choose which process to debug when a fork() happens
3395 HP has donated a curses-based terminal user interface (TUI). To get
3396 it, build with --enable-tui. Although this can be enabled for any
3397 configuration, at present it only works for native HP debugging.
3399 * GDB remote protocol additions
3401 A new protocol packet 'X' that writes binary data is now available.
3402 Default behavior is to try 'X', then drop back to 'M' if the stub
3403 fails to respond. The settable variable `remotebinarydownload'
3404 allows explicit control over the use of 'X'.
3406 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3407 full 64-bit address. The command
3409 set remoteaddresssize 32
3411 can be used to revert to the old behaviour. For existing remote stubs
3412 the change should not be noticed, as the additional address information
3415 In order to assist in debugging stubs, you may use the maintenance
3416 command `packet' to send any text string to the stub. For instance,
3418 maint packet heythere
3420 sends the packet "$heythere#<checksum>". Note that it is very easy to
3421 disrupt a debugging session by sending the wrong packet at the wrong
3424 The compare-sections command allows you to compare section data on the
3425 target to what is in the executable file without uploading or
3426 downloading, by comparing CRC checksums.
3428 * Tracing can collect general expressions
3430 You may now collect general expressions at tracepoints. This requires
3431 further additions to the target-side stub; see tracepoint.c and
3432 doc/agentexpr.texi for further details.
3434 * mask-address variable for Mips
3436 For Mips targets, you may control the zeroing of the upper 32 bits of
3437 a 64-bit address by entering `set mask-address on'. This is mainly
3438 of interest to users of embedded R4xxx and R5xxx processors.
3440 * Higher serial baud rates
3442 GDB's serial code now allows you to specify baud rates 57600, 115200,
3443 230400, and 460800 baud. (Note that your host system may not be able
3444 to achieve all of these rates.)
3448 The i960 configuration now includes an initial implementation of a
3449 builtin simulator, contributed by Jim Wilson.
3452 *** Changes in GDB-4.17:
3454 * New native configurations
3456 Alpha GNU/Linux alpha*-*-linux*
3457 Unixware 2.x i[3456]86-unixware2*
3458 Irix 6.x mips*-sgi-irix6*
3459 PowerPC GNU/Linux powerpc-*-linux*
3460 PowerPC Solaris powerpcle-*-solaris*
3461 Sparc GNU/Linux sparc-*-linux*
3462 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3466 Argonaut Risc Chip (ARC) arc-*-*
3467 Hitachi H8/300S h8300*-*-*
3468 Matsushita MN10200 w/simulator mn10200-*-*
3469 Matsushita MN10300 w/simulator mn10300-*-*
3470 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3471 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3472 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3473 Mitsubishi D10V w/simulator d10v-*-*
3474 Mitsubishi M32R/D w/simulator m32r-*-elf*
3475 Tsqware Sparclet sparclet-*-*
3476 NEC V850 w/simulator v850-*-*
3478 * New debugging protocols
3480 ARM with RDI protocol arm*-*-*
3481 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3482 DDB and LSI variants of PMON protocol mips*-*-*
3483 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3484 PowerPC with SDS protocol powerpc{,le}-*-eabi
3485 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3489 All configurations can now understand and use the DWARF 2 debugging
3490 format. The choice is automatic, if the symbol file contains DWARF 2
3495 GDB now includes basic Java language support. This support is
3496 only useful with Java compilers that produce native machine code.
3498 * solib-absolute-prefix and solib-search-path
3500 For SunOS and SVR4 shared libraries, you may now set the prefix for
3501 loading absolute shared library symbol files, and the search path for
3502 locating non-absolute shared library symbol files.
3504 * Live range splitting
3506 GDB can now effectively debug code for which GCC has performed live
3507 range splitting as part of its optimization. See gdb/doc/LRS for
3508 more details on the expected format of the stabs information.
3512 GDB's support for the GNU Hurd, including thread debugging, has been
3513 updated to work with current versions of the Hurd.
3517 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3518 instruction set. ARM GDB automatically detects when Thumb
3519 instructions are in use, and adjusts disassembly and backtracing
3524 GDB's MIPS target configurations now handle the MIP16 16-bit
3529 GDB now includes support for overlays; if an executable has been
3530 linked such that multiple sections are based at the same address, GDB
3531 will decide which section to use for symbolic info. You can choose to
3532 control the decision manually, using overlay commands, or implement
3533 additional target-side support and use "overlay load-target" to bring
3534 in the overlay mapping. Do "help overlay" for more detail.
3538 The command "info symbol <address>" displays information about
3539 the symbol at the specified address.
3543 The standard remote protocol now includes an extension that allows
3544 asynchronous collection and display of trace data. This requires
3545 extensive support in the target-side debugging stub. Tracing mode
3546 includes a new interaction mode in GDB and new commands: see the
3547 file tracepoint.c for more details.
3551 Configurations for embedded MIPS now include a simulator contributed
3552 by Cygnus Solutions. The simulator supports the instruction sets
3553 of most MIPS variants.
3557 Sparc configurations may now include the ERC32 simulator contributed
3558 by the European Space Agency. The simulator is not built into
3559 Sparc targets by default; configure with --enable-sim to include it.
3563 For target configurations that may include multiple variants of a
3564 basic architecture (such as MIPS and SH), you may now set the
3565 architecture explicitly. "set arch" sets, "info arch" lists
3566 the possible architectures.
3568 *** Changes in GDB-4.16:
3570 * New native configurations
3572 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3573 M68K NetBSD m68k-*-netbsd*
3574 PowerPC AIX 4.x powerpc-*-aix*
3575 PowerPC MacOS powerpc-*-macos*
3576 PowerPC Windows NT powerpcle-*-cygwin32
3577 RS/6000 AIX 4.x rs6000-*-aix4*
3581 ARM with RDP protocol arm-*-*
3582 I960 with MON960 i960-*-coff
3583 MIPS VxWorks mips*-*-vxworks*
3584 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3585 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3587 Matra Sparclet sparclet-*-*
3591 The powerpc-eabi configuration now includes the PSIM simulator,
3592 contributed by Andrew Cagney, with assistance from Mike Meissner.
3593 PSIM is a very elaborate model of the PowerPC, including not only
3594 basic instruction set execution, but also details of execution unit
3595 performance and I/O hardware. See sim/ppc/README for more details.
3599 GDB now works with Solaris 2.5.
3601 * Windows 95/NT native
3603 GDB will now work as a native debugger on Windows 95 and Windows NT.
3604 To build it from source, you must use the "gnu-win32" environment,
3605 which uses a DLL to emulate enough of Unix to run the GNU tools.
3606 Further information, binaries, and sources are available at
3607 ftp.cygnus.com, under pub/gnu-win32.
3609 * dont-repeat command
3611 If a user-defined command includes the command `dont-repeat', then the
3612 command will not be repeated if the user just types return. This is
3613 useful if the command is time-consuming to run, so that accidental
3614 extra keystrokes don't run the same command many times.
3616 * Send break instead of ^C
3618 The standard remote protocol now includes an option to send a break
3619 rather than a ^C to the target in order to interrupt it. By default,
3620 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3622 * Remote protocol timeout
3624 The standard remote protocol includes a new variable `remotetimeout'
3625 that allows you to set the number of seconds before GDB gives up trying
3626 to read from the target. The default value is 2.
3628 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3630 By default GDB will automatically keep track of objects as they are
3631 loaded and unloaded by the dynamic linker. By using the command `set
3632 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3633 when shared library events occur, thus allowing you to set breakpoints
3634 in shared libraries which are explicitly loaded by the inferior.
3636 Note this feature does not work on hpux8. On hpux9 you must link
3637 /usr/lib/end.o into your program. This feature should work
3638 automatically on hpux10.
3640 * Irix 5.x hardware watchpoint support
3642 Irix 5 configurations now support the use of hardware watchpoints.
3644 * Mips protocol "SYN garbage limit"
3646 When debugging a Mips target using the `target mips' protocol, you
3647 may set the number of characters that GDB will ignore by setting
3648 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3649 every character. The default value is 1050.
3651 * Recording and replaying remote debug sessions
3653 If you set `remotelogfile' to the name of a file, gdb will write to it
3654 a recording of a remote debug session. This recording may then be
3655 replayed back to gdb using "gdbreplay". See gdbserver/README for
3656 details. This is useful when you have a problem with GDB while doing
3657 remote debugging; you can make a recording of the session and send it
3658 to someone else, who can then recreate the problem.
3660 * Speedups for remote debugging
3662 GDB includes speedups for downloading and stepping MIPS systems using
3663 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3664 and more efficient S-record downloading.
3666 * Memory use reductions and statistics collection
3668 GDB now uses less memory and reports statistics about memory usage.
3669 Try the `maint print statistics' command, for example.
3671 *** Changes in GDB-4.15:
3673 * Psymtabs for XCOFF
3675 The symbol reader for AIX GDB now uses partial symbol tables. This
3676 can greatly improve startup time, especially for large executables.
3678 * Remote targets use caching
3680 Remote targets now use a data cache to speed up communication with the
3681 remote side. The data cache could lead to incorrect results because
3682 it doesn't know about volatile variables, thus making it impossible to
3683 debug targets which use memory mapped I/O devices. `set remotecache
3684 off' turns the the data cache off.
3686 * Remote targets may have threads
3688 The standard remote protocol now includes support for multiple threads
3689 in the target system, using new protocol commands 'H' and 'T'. See
3690 gdb/remote.c for details.
3694 If GDB is configured with `--enable-netrom', then it will include
3695 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3696 acts as though it is a bank of ROM on the target board, but you can
3697 write into it over the network. GDB's support consists only of
3698 support for fast loading into the emulated ROM; to debug, you must use
3699 another protocol, such as standard remote protocol. The usual
3700 sequence is something like
3702 target nrom <netrom-hostname>
3704 target remote <netrom-hostname>:1235
3708 GDB now includes support for the Apple Macintosh, as a host only. It
3709 may be run as either an MPW tool or as a standalone application, and
3710 it can debug through the serial port. All the usual GDB commands are
3711 available, but to the target command, you must supply "serial" as the
3712 device type instead of "/dev/ttyXX". See mpw-README in the main
3713 directory for more information on how to build. The MPW configuration
3714 scripts */mpw-config.in support only a few targets, and only the
3715 mips-idt-ecoff target has been tested.
3719 GDB configuration now uses autoconf. This is not user-visible,
3720 but does simplify configuration and building.
3724 GDB now supports hpux10.
3726 *** Changes in GDB-4.14:
3728 * New native configurations
3730 x86 FreeBSD i[345]86-*-freebsd
3731 x86 NetBSD i[345]86-*-netbsd
3732 NS32k NetBSD ns32k-*-netbsd
3733 Sparc NetBSD sparc-*-netbsd
3737 A29K VxWorks a29k-*-vxworks
3738 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3739 CPU32 EST-300 emulator m68*-*-est*
3740 PowerPC ELF powerpc-*-elf
3743 * Alpha OSF/1 support for procfs
3745 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3746 possible to attach to running processes. As the mounting of the /proc
3747 filesystem is optional on the Alpha, GDB automatically determines
3748 the availability of /proc during startup. This can lead to problems
3749 if /proc is unmounted after GDB has been started.
3751 * Arguments to user-defined commands
3753 User commands may accept up to 10 arguments separated by whitespace.
3754 Arguments are accessed within the user command via $arg0..$arg9. A
3757 print $arg0 + $arg1 + $arg2
3759 To execute the command use:
3762 Defines the command "adder" which prints the sum of its three arguments.
3763 Note the arguments are text substitutions, so they may reference variables,
3764 use complex expressions, or even perform inferior function calls.
3766 * New `if' and `while' commands
3768 This makes it possible to write more sophisticated user-defined
3769 commands. Both commands take a single argument, which is the
3770 expression to evaluate, and must be followed by the commands to
3771 execute, one per line, if the expression is nonzero, the list being
3772 terminated by the word `end'. The `if' command list may include an
3773 `else' word, which causes the following commands to be executed only
3774 if the expression is zero.
3776 * Fortran source language mode
3778 GDB now includes partial support for Fortran 77. It will recognize
3779 Fortran programs and can evaluate a subset of Fortran expressions, but
3780 variables and functions may not be handled correctly. GDB will work
3781 with G77, but does not yet know much about symbols emitted by other
3784 * Better HPUX support
3786 Most debugging facilities now work on dynamic executables for HPPAs
3787 running hpux9 or later. You can attach to running dynamically linked
3788 processes, but by default the dynamic libraries will be read-only, so
3789 for instance you won't be able to put breakpoints in them. To change
3790 that behavior do the following before running the program:
3796 This will cause the libraries to be mapped private and read-write.
3797 To revert to the normal behavior, do this:
3803 You cannot set breakpoints or examine data in the library until after
3804 the library is loaded if the function/data symbols do not have
3807 GDB can now also read debug symbols produced by the HP C compiler on
3808 HPPAs (sorry, no C++, Fortran or 68k support).
3810 * Target byte order now dynamically selectable
3812 You can choose which byte order to use with a target system, via the
3813 commands "set endian big" and "set endian little", and you can see the
3814 current setting by using "show endian". You can also give the command
3815 "set endian auto", in which case GDB will use the byte order
3816 associated with the executable. Currently, only embedded MIPS
3817 configurations support dynamic selection of target byte order.
3819 * New DOS host serial code
3821 This version uses DPMI interrupts to handle buffered I/O, so you
3822 no longer need to run asynctsr when debugging boards connected to
3825 *** Changes in GDB-4.13:
3827 * New "complete" command
3829 This lists all the possible completions for the rest of the line, if it
3830 were to be given as a command itself. This is intended for use by emacs.
3832 * Trailing space optional in prompt
3834 "set prompt" no longer adds a space for you after the prompt you set. This
3835 allows you to set a prompt which ends in a space or one that does not.
3837 * Breakpoint hit counts
3839 "info break" now displays a count of the number of times the breakpoint
3840 has been hit. This is especially useful in conjunction with "ignore"; you
3841 can ignore a large number of breakpoint hits, look at the breakpoint info
3842 to see how many times the breakpoint was hit, then run again, ignoring one
3843 less than that number, and this will get you quickly to the last hit of
3846 * Ability to stop printing at NULL character
3848 "set print null-stop" will cause GDB to stop printing the characters of
3849 an array when the first NULL is encountered. This is useful when large
3850 arrays actually contain only short strings.
3852 * Shared library breakpoints
3854 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3855 breakpoints in shared libraries before the executable is run.
3857 * Hardware watchpoints
3859 There is a new hardware breakpoint for the watch command for sparclite
3860 targets. See gdb/sparclite/hw_breakpoint.note.
3862 Hardware watchpoints are also now supported under GNU/Linux.
3866 Annotations have been added. These are for use with graphical interfaces,
3867 and are still experimental. Currently only gdba.el uses these.
3869 * Improved Irix 5 support
3871 GDB now works properly with Irix 5.2.
3873 * Improved HPPA support
3875 GDB now works properly with the latest GCC and GAS.
3877 * New native configurations
3879 Sequent PTX4 i[34]86-sequent-ptx4
3880 HPPA running OSF/1 hppa*-*-osf*
3881 Atari TT running SVR4 m68*-*-sysv4*
3882 RS/6000 LynxOS rs6000-*-lynxos*
3886 OS/9000 i[34]86-*-os9k
3887 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3890 * Hitachi SH7000 and E7000-PC ICE support
3892 There is now support for communicating with the Hitachi E7000-PC ICE.
3893 This is available automatically when GDB is configured for the SH.
3897 As usual, a variety of small fixes and improvements, both generic
3898 and configuration-specific. See the ChangeLog for more detail.
3900 *** Changes in GDB-4.12:
3902 * Irix 5 is now supported
3906 GDB-4.12 on the HPPA has a number of changes which make it unable
3907 to debug the output from the currently released versions of GCC and
3908 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3909 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3910 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3913 *** Changes in GDB-4.11:
3915 * User visible changes:
3919 The "set remotedebug" option is now consistent between the mips remote
3920 target, remote targets using the gdb-specific protocol, UDI (AMD's
3921 debug protocol for the 29k) and the 88k bug monitor. It is now an
3922 integer specifying a debug level (normally 0 or 1, but 2 means more
3923 debugging info for the mips target).
3925 * DEC Alpha native support
3927 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3928 debug info, but GDB works fairly well with the DEC compiler and should
3929 work with a future GCC release. See the README file for a few
3930 Alpha-specific notes.
3932 * Preliminary thread implementation
3934 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3936 * LynxOS native and target support for 386
3938 This release has been hosted on LynxOS 2.2, and also can be configured
3939 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3942 * Improvements in C++ mangling/demangling.
3944 This release has much better g++ debugging, specifically in name
3945 mangling/demangling, virtual function calls, print virtual table,
3946 call methods, ...etc.
3948 *** Changes in GDB-4.10:
3950 * User visible changes:
3952 Remote debugging using the GDB-specific (`target remote') protocol now
3953 supports the `load' command. This is only useful if you have some
3954 other way of getting the stub to the target system, and you can put it
3955 somewhere in memory where it won't get clobbered by the download.
3957 Filename completion now works.
3959 When run under emacs mode, the "info line" command now causes the
3960 arrow to point to the line specified. Also, "info line" prints
3961 addresses in symbolic form (as well as hex).
3963 All vxworks based targets now support a user settable option, called
3964 vxworks-timeout. This option represents the number of seconds gdb
3965 should wait for responses to rpc's. You might want to use this if
3966 your vxworks target is, perhaps, a slow software simulator or happens
3967 to be on the far side of a thin network line.
3971 This release contains support for using a DEC alpha as a GDB host for
3972 cross debugging. Native alpha debugging is not supported yet.
3975 *** Changes in GDB-4.9:
3979 This is the first GDB release which is accompanied by a matching testsuite.
3980 The testsuite requires installation of dejagnu, which should be available
3981 via ftp from most sites that carry GNU software.
3985 'Cfront' style demangling has had its name changed to 'ARM' style, to
3986 emphasize that it was written from the specifications in the C++ Annotated
3987 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3988 disclaimers, it still generated too much confusion with users attempting to
3989 use gdb with AT&T cfront.
3993 GDB now uses a standard remote interface to a simulator library.
3994 So far, the library contains simulators for the Zilog Z8001/2, the
3995 Hitachi H8/300, H8/500 and Super-H.
3997 * New targets supported
3999 H8/300 simulator h8300-hitachi-hms or h8300hms
4000 H8/500 simulator h8500-hitachi-hms or h8500hms
4001 SH simulator sh-hitachi-hms or sh
4002 Z8000 simulator z8k-zilog-none or z8ksim
4003 IDT MIPS board over serial line mips-idt-ecoff
4005 Cross-debugging to GO32 targets is supported. It requires a custom
4006 version of the i386-stub.c module which is integrated with the
4007 GO32 memory extender.
4009 * New remote protocols
4011 MIPS remote debugging protocol.
4013 * New source languages supported
4015 This version includes preliminary support for Chill, a Pascal like language
4016 used by telecommunications companies. Chill support is also being integrated
4017 into the GNU compiler, but we don't know when it will be publically available.
4020 *** Changes in GDB-4.8:
4022 * HP Precision Architecture supported
4024 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4025 version of this support was available as a set of patches from the
4026 University of Utah. GDB does not support debugging of programs
4027 compiled with the HP compiler, because HP will not document their file
4028 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4029 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4031 Many problems in the preliminary version have been fixed.
4033 * Faster and better demangling
4035 We have improved template demangling and fixed numerous bugs in the GNU style
4036 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4037 character types (wchar_t) are now supported. Demangling of each symbol is now
4038 only done once, and is cached when the symbol table for a file is read in.
4039 This results in a small increase in memory usage for C programs, a moderate
4040 increase in memory usage for C++ programs, and a fantastic speedup in
4043 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4044 from the specifications in the Annotated Reference Manual, which AT&T's
4045 compiler does not actually implement.
4047 * G++ multiple inheritance compiler problem
4049 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4050 inheritance lattices was reworked to properly discover ambiguities. We
4051 recently found an example which causes this new algorithm to fail in a
4052 very subtle way, producing bad debug information for those classes.
4053 The file 'gcc.patch' (in this directory) can be applied to gcc to
4054 circumvent the problem. A future GCC release will contain a complete
4057 The previous G++ debug info problem (mentioned below for the gdb-4.7
4058 release) is fixed in gcc version 2.3.2.
4060 * Improved configure script
4062 The `configure' script will now attempt to guess your system type if
4063 you don't supply a host system type. The old scheme of supplying a
4064 host system triplet is preferable over using this. All the magic is
4065 done in the new `config.guess' script. Examine it for details.
4067 We have also brought our configure script much more in line with the FSF's
4068 version. It now supports the --with-xxx options. In particular,
4069 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4070 The resulting GDB will not be able to read arbitrary object file formats --
4071 only the format ``expected'' to be used on the configured target system.
4072 We hope to make this the default in a future release.
4074 * Documentation improvements
4076 There's new internal documentation on how to modify GDB, and how to
4077 produce clean changes to the code. We implore people to read it
4078 before submitting changes.
4080 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4081 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4082 `info' files are also provided. To build `info' files from scratch,
4083 you will need the latest `makeinfo' release, which will be available in
4084 a future texinfo-X.Y release.
4086 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4087 We're not sure exactly which versions have this problem, but it has
4088 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4089 or better. If that isn't possible, there is a patch in
4090 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4091 around this problem.
4095 GDB now supports array constants that can be used in expressions typed in by
4096 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4097 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4100 The new directory `gdb/sparclite' contains a program that demonstrates
4101 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4103 * New native hosts supported
4105 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4106 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4108 * New targets supported
4110 AMD 29k family via UDI a29k-amd-udi or udi29k
4112 * New file formats supported
4114 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4115 HPUX core files, and SCO 3.2v2 core files.
4119 Attaching to processes now works again; thanks for the many bug reports.
4121 We have also stomped on a bunch of core dumps caused by
4122 printf_filtered("%s") problems.
4124 We eliminated a copyright problem on the rpc and ptrace header files
4125 for VxWorks, which was discovered at the last minute during the 4.7
4126 release. You should now be able to build a VxWorks GDB.
4128 You can now interrupt gdb while an attached process is running. This
4129 will cause the attached process to stop, and give control back to GDB.
4131 We fixed problems caused by using too many file descriptors
4132 for reading symbols from object files and libraries. This was
4133 especially a problem for programs that used many (~100) shared
4136 The `step' command now only enters a subroutine if there is line number
4137 information for the subroutine. Otherwise it acts like the `next'
4138 command. Previously, `step' would enter subroutines if there was
4139 any debugging information about the routine. This avoids problems
4140 when using `cc -g1' on MIPS machines.
4142 * Internal improvements
4144 GDB's internal interfaces have been improved to make it easier to support
4145 debugging of multiple languages in the future.
4147 GDB now uses a common structure for symbol information internally.
4148 Minimal symbols (derived from linkage symbols in object files), partial
4149 symbols (from a quick scan of debug information), and full symbols
4150 contain a common subset of information, making it easier to write
4151 shared code that handles any of them.
4153 * New command line options
4155 We now accept --silent as an alias for --quiet.
4159 The memory-mapped-malloc library is now licensed under the GNU Library
4160 General Public License.
4162 *** Changes in GDB-4.7:
4164 * Host/native/target split
4166 GDB has had some major internal surgery to untangle the support for
4167 hosts and remote targets. Now, when you configure GDB for a remote
4168 target, it will no longer load in all of the support for debugging
4169 local programs on the host. When fully completed and tested, this will
4170 ensure that arbitrary host/target combinations are possible.
4172 The primary conceptual shift is to separate the non-portable code in
4173 GDB into three categories. Host specific code is required any time GDB
4174 is compiled on that host, regardless of the target. Target specific
4175 code relates to the peculiarities of the target, but can be compiled on
4176 any host. Native specific code is everything else: it can only be
4177 built when the host and target are the same system. Child process
4178 handling and core file support are two common `native' examples.
4180 GDB's use of /proc for controlling Unix child processes is now cleaner.
4181 It has been split out into a single module under the `target_ops' vector,
4182 plus two native-dependent functions for each system that uses /proc.
4184 * New hosts supported
4186 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4187 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4188 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4190 * New targets supported
4192 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4193 68030 and CPU32 m68030-*-*, m68332-*-*
4195 * New native hosts supported
4197 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4198 (386bsd is not well tested yet)
4199 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4201 * New file formats supported
4203 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4204 supports reading of `a.out.adobe' object files, which are an a.out
4205 format extended with minimal information about multiple sections.
4209 `show copying' is the same as the old `info copying'.
4210 `show warranty' is the same as `info warrantee'.
4211 These were renamed for consistency. The old commands continue to work.
4213 `info handle' is a new alias for `info signals'.
4215 You can now define pre-command hooks, which attach arbitrary command
4216 scripts to any command. The commands in the hook will be executed
4217 prior to the user's command. You can also create a hook which will be
4218 executed whenever the program stops. See gdb.texinfo.
4222 We now deal with Cfront style name mangling, and can even extract type
4223 info from mangled symbols. GDB can automatically figure out which
4224 symbol mangling style your C++ compiler uses.
4226 Calling of methods and virtual functions has been improved as well.
4230 The crash that occured when debugging Sun Ansi-C compiled binaries is
4231 fixed. This was due to mishandling of the extra N_SO stabs output
4234 We also finally got Ultrix 4.2 running in house, and fixed core file
4235 support, with help from a dozen people on the net.
4237 John M. Farrell discovered that the reason that single-stepping was so
4238 slow on all of the Mips based platforms (primarily SGI and DEC) was
4239 that we were trying to demangle and lookup a symbol used for internal
4240 purposes on every instruction that was being stepped through. Changing
4241 the name of that symbol so that it couldn't be mistaken for a C++
4242 mangled symbol sped things up a great deal.
4244 Rich Pixley sped up symbol lookups in general by getting much smarter
4245 about when C++ symbol mangling is necessary. This should make symbol
4246 completion (TAB on the command line) much faster. It's not as fast as
4247 we'd like, but it's significantly faster than gdb-4.6.
4251 A new user controllable variable 'call_scratch_address' can
4252 specify the location of a scratch area to be used when GDB
4253 calls a function in the target. This is necessary because the
4254 usual method of putting the scratch area on the stack does not work
4255 in systems that have separate instruction and data spaces.
4257 We integrated changes to support the 29k UDI (Universal Debugger
4258 Interface), but discovered at the last minute that we didn't have all
4259 of the appropriate copyright paperwork. We are working with AMD to
4260 resolve this, and hope to have it available soon.
4264 We have sped up the remote serial line protocol, especially for targets
4265 with lots of registers. It now supports a new `expedited status' ('T')
4266 message which can be used in place of the existing 'S' status message.
4267 This allows the remote stub to send only the registers that GDB
4268 needs to make a quick decision about single-stepping or conditional
4269 breakpoints, eliminating the need to fetch the entire register set for
4270 each instruction being stepped through.
4272 The GDB remote serial protocol now implements a write-through cache for
4273 registers, only re-reading the registers if the target has run.
4275 There is also a new remote serial stub for SPARC processors. You can
4276 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4277 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4278 processor with a serial port.
4282 Configure.in files have become much easier to read and modify. A new
4283 `table driven' format makes it more obvious what configurations are
4284 supported, and what files each one uses.
4288 There is a new opcodes library which will eventually contain all of the
4289 disassembly routines and opcode tables. At present, it only contains
4290 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4291 disassembler (binutils/objdump) to share these routines.
4293 The libiberty library is now copylefted under the GNU Library General
4294 Public License. This allows more liberal use, and was done so libg++
4295 can use it. This makes no difference to GDB, since the Library License
4296 grants all the rights from the General Public License.
4300 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4301 reference to the stabs symbol info used by the debugger. It is (as far
4302 as we know) the only published document on this fascinating topic. We
4303 encourage you to read it, compare it to the stabs information on your
4304 system, and send improvements on the document in general (to
4305 bug-gdb@prep.ai.mit.edu).
4307 And, of course, many bugs have been fixed.
4310 *** Changes in GDB-4.6:
4312 * Better support for C++ function names
4314 GDB now accepts as input the "demangled form" of C++ overloaded function
4315 names and member function names, and can do command completion on such names
4316 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4317 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4318 Make use of command completion, it is your friend.
4320 GDB also now accepts a variety of C++ mangled symbol formats. They are
4321 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4322 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4323 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4324 for the list of formats.
4326 * G++ symbol mangling problem
4328 Recent versions of gcc have a bug in how they emit debugging information for
4329 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4330 directory) can be applied to gcc to fix the problem. Alternatively, if you
4331 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4332 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4333 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4336 * New 'maintenance' command
4338 All of the commands related to hacking GDB internals have been moved out of
4339 the main command set, and now live behind the 'maintenance' command. This
4340 can also be abbreviated as 'mt'. The following changes were made:
4342 dump-me -> maintenance dump-me
4343 info all-breakpoints -> maintenance info breakpoints
4344 printmsyms -> maintenance print msyms
4345 printobjfiles -> maintenance print objfiles
4346 printpsyms -> maintenance print psymbols
4347 printsyms -> maintenance print symbols
4349 The following commands are new:
4351 maintenance demangle Call internal GDB demangler routine to
4352 demangle a C++ link name and prints the result.
4353 maintenance print type Print a type chain for a given symbol
4355 * Change to .gdbinit file processing
4357 We now read the $HOME/.gdbinit file before processing the argv arguments
4358 (e.g. reading symbol files or core files). This allows global parameters to
4359 be set, which will apply during the symbol reading. The ./.gdbinit is still
4360 read after argv processing.
4362 * New hosts supported
4364 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4366 GNU/Linux support i386-unknown-linux or linux
4368 We are also including code to support the HP/PA running BSD and HPUX. This
4369 is almost guaranteed not to work, as we didn't have time to test or build it
4370 for this release. We are including it so that the more adventurous (or
4371 masochistic) of you can play with it. We also had major problems with the
4372 fact that the compiler that we got from HP doesn't support the -g option.
4375 * New targets supported
4377 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4379 * More smarts about finding #include files
4381 GDB now remembers the compilation directory for all include files, and for
4382 all files from which C is generated (like yacc and lex sources). This
4383 greatly improves GDB's ability to find yacc/lex sources, and include files,
4384 especially if you are debugging your program from a directory different from
4385 the one that contains your sources.
4387 We also fixed a bug which caused difficulty with listing and setting
4388 breakpoints in include files which contain C code. (In the past, you had to
4389 try twice in order to list an include file that you hadn't looked at before.)
4391 * Interesting infernals change
4393 GDB now deals with arbitrary numbers of sections, where the symbols for each
4394 section must be relocated relative to that section's landing place in the
4395 target's address space. This work was needed to support ELF with embedded
4396 stabs used by Solaris-2.0.
4398 * Bug fixes (of course!)
4400 There have been loads of fixes for the following things:
4401 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4402 i960, stabs, DOS(GO32), procfs, etc...
4404 See the ChangeLog for details.
4406 *** Changes in GDB-4.5:
4408 * New machines supported (host and target)
4410 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4412 SGI Irix-4.x mips-sgi-irix4 or iris4
4414 * New malloc package
4416 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4417 Mmalloc is capable of handling mutiple heaps of memory. It is also
4418 capable of saving a heap to a file, and then mapping it back in later.
4419 This can be used to greatly speedup the startup of GDB by using a
4420 pre-parsed symbol table which lives in a mmalloc managed heap. For
4421 more details, please read mmalloc/mmalloc.texi.
4425 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4426 'help info proc' for details.
4428 * MIPS ecoff symbol table format
4430 The code that reads MIPS symbol table format is now supported on all hosts.
4431 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4434 * File name changes for MS-DOS
4436 Many files in the config directories have been renamed to make it easier to
4437 support GDB on MS-DOSe systems (which have very restrictive file name
4438 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4439 environment) is close to working but has some remaining problems. Note
4440 that debugging of DOS programs is not supported, due to limitations
4441 in the ``operating system'', but it can be used to host cross-debugging.
4443 * Cross byte order fixes
4445 Many fixes have been made to support cross debugging of Sparc and MIPS
4446 targets from hosts whose byte order differs.
4448 * New -mapped and -readnow options
4450 If memory-mapped files are available on your system through the 'mmap'
4451 system call, you can use the -mapped option on the `file' or
4452 `symbol-file' commands to cause GDB to write the symbols from your
4453 program into a reusable file. If the program you are debugging is
4454 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4455 Future GDB debugging sessions will notice the presence of this file,
4456 and will quickly map in symbol information from it, rather than reading
4457 the symbol table from the executable program. Using the '-mapped'
4458 option in a GDB `file' or `symbol-file' command has the same effect as
4459 starting GDB with the '-mapped' command-line option.
4461 You can cause GDB to read the entire symbol table immediately by using
4462 the '-readnow' option with any of the commands that load symbol table
4463 information (or on the GDB command line). This makes the command
4464 slower, but makes future operations faster.
4466 The -mapped and -readnow options are typically combined in order to
4467 build a `fred.syms' file that contains complete symbol information.
4468 A simple GDB invocation to do nothing but build a `.syms' file for future
4471 gdb -batch -nx -mapped -readnow programname
4473 The `.syms' file is specific to the host machine on which GDB is run.
4474 It holds an exact image of GDB's internal symbol table. It cannot be
4475 shared across multiple host platforms.
4477 * longjmp() handling
4479 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4480 siglongjmp() without losing control. This feature has not yet been ported to
4481 all systems. It currently works on many 386 platforms, all MIPS-based
4482 platforms (SGI, DECstation, etc), and Sun3/4.
4486 Preliminary work has been put in to support the new Solaris OS from Sun. At
4487 this time, it can control and debug processes, but it is not capable of
4492 As always, many many bug fixes. The major areas were with g++, and mipsread.
4493 People using the MIPS-based platforms should experience fewer mysterious
4494 crashes and trashed symbol tables.
4496 *** Changes in GDB-4.4:
4498 * New machines supported (host and target)
4500 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4502 BSD Reno on Vax vax-dec-bsd
4503 Ultrix on Vax vax-dec-ultrix
4505 * New machines supported (target)
4507 AMD 29000 embedded, using EBMON a29k-none-none
4511 GDB continues to improve its handling of C++. `References' work better.
4512 The demangler has also been improved, and now deals with symbols mangled as
4513 per the Annotated C++ Reference Guide.
4515 GDB also now handles `stabs' symbol information embedded in MIPS
4516 `ecoff' symbol tables. Since the ecoff format was not easily
4517 extensible to handle new languages such as C++, this appeared to be a
4518 good way to put C++ debugging info into MIPS binaries. This option
4519 will be supported in the GNU C compiler, version 2, when it is
4522 * New features for SVR4
4524 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4525 shared libraries. Debugging dynamically linked programs should present
4526 only minor differences from debugging statically linked programs.
4528 The `info proc' command will print out information about any process
4529 on an SVR4 system (including the one you are debugging). At the moment,
4530 it prints the address mappings of the process.
4532 If you bring up GDB on another SVR4 system, please send mail to
4533 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4535 * Better dynamic linking support in SunOS
4537 Reading symbols from shared libraries which contain debugging symbols
4538 now works properly. However, there remain issues such as automatic
4539 skipping of `transfer vector' code during function calls, which
4540 make it harder to debug code in a shared library, than to debug the
4541 same code linked statically.
4545 GDB is now using the latest `getopt' routines from the FSF. This
4546 version accepts the -- prefix for options with long names. GDB will
4547 continue to accept the old forms (-option and +option) as well.
4548 Various single letter abbreviations for options have been explicity
4549 added to the option table so that they won't get overshadowed in the
4550 future by other options that begin with the same letter.
4554 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4555 Many assorted bugs have been handled. Many more remain to be handled.
4556 See the various ChangeLog files (primarily in gdb and bfd) for details.
4559 *** Changes in GDB-4.3:
4561 * New machines supported (host and target)
4563 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4564 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4565 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4567 * Almost SCO Unix support
4569 We had hoped to support:
4570 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4571 (except for core file support), but we discovered very late in the release
4572 that it has problems with process groups that render gdb unusable. Sorry
4573 about that. I encourage people to fix it and post the fixes.
4575 * Preliminary ELF and DWARF support
4577 GDB can read ELF object files on System V Release 4, and can handle
4578 debugging records for C, in DWARF format, in ELF files. This support
4579 is preliminary. If you bring up GDB on another SVR4 system, please
4580 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4585 GDB now uses the latest `readline' library. One user-visible change
4586 is that two tabs will list possible command completions, which previously
4587 required typing M-? (meta-question mark, or ESC ?).
4591 The `stepi' bug that many of you noticed has been squashed.
4592 Many bugs in C++ have been handled. Many more remain to be handled.
4593 See the various ChangeLog files (primarily in gdb and bfd) for details.
4595 * State of the MIPS world (in case you wondered):
4597 GDB can understand the symbol tables emitted by the compilers
4598 supplied by most vendors of MIPS-based machines, including DEC. These
4599 symbol tables are in a format that essentially nobody else uses.
4601 Some versions of gcc come with an assembler post-processor called
4602 mips-tfile. This program is required if you want to do source-level
4603 debugging of gcc-compiled programs. I believe FSF does not ship
4604 mips-tfile with gcc version 1, but it will eventually come with gcc
4607 Debugging of g++ output remains a problem. g++ version 1.xx does not
4608 really support it at all. (If you're lucky, you should be able to get
4609 line numbers and stack traces to work, but no parameters or local
4610 variables.) With some work it should be possible to improve the
4613 When gcc version 2 is released, you will have somewhat better luck.
4614 However, even then you will get confusing results for inheritance and
4617 We will eventually provide full debugging of g++ output on
4618 DECstations. This will probably involve some kind of stabs-in-ecoff
4619 encapulation, but the details have not been worked out yet.
4622 *** Changes in GDB-4.2:
4624 * Improved configuration
4626 Only one copy of `configure' exists now, and it is not self-modifying.
4627 Porting BFD is simpler.
4631 The `step' and `next' commands now only stop at the first instruction
4632 of a source line. This prevents the multiple stops that used to occur
4633 in switch statements, for-loops, etc. `Step' continues to stop if a
4634 function that has debugging information is called within the line.
4638 Lots of small bugs fixed. More remain.
4640 * New host supported (not target)
4642 Intel 386 PC clone running Mach i386-none-mach
4645 *** Changes in GDB-4.1:
4647 * Multiple source language support
4649 GDB now has internal scaffolding to handle several source languages.
4650 It determines the type of each source file from its filename extension,
4651 and will switch expression parsing and number formatting to match the
4652 language of the function in the currently selected stack frame.
4653 You can also specifically set the language to be used, with
4654 `set language c' or `set language modula-2'.
4658 GDB now has preliminary support for the GNU Modula-2 compiler,
4659 currently under development at the State University of New York at
4660 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4661 continue through the fall of 1991 and into 1992.
4663 Other Modula-2 compilers are currently not supported, and attempting to
4664 debug programs compiled with them will likely result in an error as the
4665 symbol table is read. Feel free to work on it, though!
4667 There are hooks in GDB for strict type checking and range checking,
4668 in the `Modula-2 philosophy', but they do not currently work.
4672 GDB can now write to executable and core files (e.g. patch
4673 a variable's value). You must turn this switch on, specify
4674 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4675 by assigning a new value to a variable. Modifications take
4678 * Automatic SunOS shared library reading
4680 When you run your program, GDB automatically determines where its
4681 shared libraries (if any) have been loaded, and reads their symbols.
4682 The `share' command is no longer needed. This also works when
4683 examining core files.
4687 You can specify the number of lines that the `list' command shows.
4690 * New machines supported (host and target)
4692 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4693 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4694 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4696 * New hosts supported (not targets)
4698 IBM RT/PC: romp-ibm-aix or rtpc
4700 * New targets supported (not hosts)
4702 AMD 29000 embedded with COFF a29k-none-coff
4703 AMD 29000 embedded with a.out a29k-none-aout
4704 Ultracomputer remote kernel debug a29k-nyu-kern
4706 * New remote interfaces
4712 *** Changes in GDB-4.0:
4716 Wide output is wrapped at good places to make the output more readable.
4718 Gdb now supports cross-debugging from a host machine of one type to a
4719 target machine of another type. Communication with the target system
4720 is over serial lines. The ``target'' command handles connecting to the
4721 remote system; the ``load'' command will download a program into the
4722 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4723 also supports debugging of realtime processes running under VxWorks,
4724 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4725 stub on the target system.
4727 New CPUs supported include the AMD 29000 and Intel 960.
4729 GDB now reads object files and symbol tables via a ``binary file''
4730 library, which allows a single copy of GDB to debug programs of multiple
4731 object file types such as a.out and coff.
4733 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4734 refcard.dvi and refcard.ps are available to format it).
4737 * Control-Variable user interface simplified
4739 All variables that control the operation of the debugger can be set
4740 by the ``set'' command, and displayed by the ``show'' command.
4742 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4743 ``Show prompt'' produces the response:
4744 Gdb's prompt is new-gdb=>.
4746 What follows are the NEW set commands. The command ``help set'' will
4747 print a complete list of old and new set commands. ``help set FOO''
4748 will give a longer description of the variable FOO. ``show'' will show
4749 all of the variable descriptions and their current settings.
4751 confirm on/off: Enables warning questions for operations that are
4752 hard to recover from, e.g. rerunning the program while
4753 it is already running. Default is ON.
4755 editing on/off: Enables EMACS style command line editing
4756 of input. Previous lines can be recalled with
4757 control-P, the current line can be edited with control-B,
4758 you can search for commands with control-R, etc.
4761 history filename NAME: NAME is where the gdb command history
4762 will be stored. The default is .gdb_history,
4763 or the value of the environment variable
4766 history size N: The size, in commands, of the command history. The
4767 default is 256, or the value of the environment variable
4770 history save on/off: If this value is set to ON, the history file will
4771 be saved after exiting gdb. If set to OFF, the
4772 file will not be saved. The default is OFF.
4774 history expansion on/off: If this value is set to ON, then csh-like
4775 history expansion will be performed on
4776 command line input. The default is OFF.
4778 radix N: Sets the default radix for input and output. It can be set
4779 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4780 in the current radix, so "set radix 10" is always a no-op.
4782 height N: This integer value is the number of lines on a page. Default
4783 is 24, the current `stty rows'' setting, or the ``li#''
4784 setting from the termcap entry matching the environment
4787 width N: This integer value is the number of characters on a line.
4788 Default is 80, the current `stty cols'' setting, or the ``co#''
4789 setting from the termcap entry matching the environment
4792 Note: ``set screensize'' is obsolete. Use ``set height'' and
4793 ``set width'' instead.
4795 print address on/off: Print memory addresses in various command displays,
4796 such as stack traces and structure values. Gdb looks
4797 more ``symbolic'' if you turn this off; it looks more
4798 ``machine level'' with it on. Default is ON.
4800 print array on/off: Prettyprint arrays. New convenient format! Default
4803 print demangle on/off: Print C++ symbols in "source" form if on,
4806 print asm-demangle on/off: Same, for assembler level printouts
4809 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4812 * Support for Epoch Environment.
4814 The epoch environment is a version of Emacs v18 with windowing. One
4815 new command, ``inspect'', is identical to ``print'', except that if you
4816 are running in the epoch environment, the value is printed in its own
4820 * Support for Shared Libraries
4822 GDB can now debug programs and core files that use SunOS shared libraries.
4823 Symbols from a shared library cannot be referenced
4824 before the shared library has been linked with the program (this
4825 happens after you type ``run'' and before the function main() is entered).
4826 At any time after this linking (including when examining core files
4827 from dynamically linked programs), gdb reads the symbols from each
4828 shared library when you type the ``sharedlibrary'' command.
4829 It can be abbreviated ``share''.
4831 sharedlibrary REGEXP: Load shared object library symbols for files
4832 matching a unix regular expression. No argument
4833 indicates to load symbols for all shared libraries.
4835 info sharedlibrary: Status of loaded shared libraries.
4840 A watchpoint stops execution of a program whenever the value of an
4841 expression changes. Checking for this slows down execution
4842 tremendously whenever you are in the scope of the expression, but is
4843 quite useful for catching tough ``bit-spreader'' or pointer misuse
4844 problems. Some machines such as the 386 have hardware for doing this
4845 more quickly, and future versions of gdb will use this hardware.
4847 watch EXP: Set a watchpoint (breakpoint) for an expression.
4849 info watchpoints: Information about your watchpoints.
4851 delete N: Deletes watchpoint number N (same as breakpoints).
4852 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4853 enable N: Re-enables watchpoint number N (same as breakpoints).
4856 * C++ multiple inheritance
4858 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4861 * C++ exception handling
4863 Gdb now supports limited C++ exception handling. Besides the existing
4864 ability to breakpoint on an exception handler, gdb can breakpoint on
4865 the raising of an exception (before the stack is peeled back to the
4868 catch FOO: If there is a FOO exception handler in the dynamic scope,
4869 set a breakpoint to catch exceptions which may be raised there.
4870 Multiple exceptions (``catch foo bar baz'') may be caught.
4872 info catch: Lists all exceptions which may be caught in the
4873 current stack frame.
4876 * Minor command changes
4878 The command ``call func (arg, arg, ...)'' now acts like the print
4879 command, except it does not print or save a value if the function's result
4880 is void. This is similar to dbx usage.
4882 The ``up'' and ``down'' commands now always print the frame they end up
4883 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4884 frames without printing.
4886 * New directory command
4888 'dir' now adds directories to the FRONT of the source search path.
4889 The path starts off empty. Source files that contain debug information
4890 about the directory in which they were compiled can be found even
4891 with an empty path; Sun CC and GCC include this information. If GDB can't
4892 find your source file in the current directory, type "dir .".
4894 * Configuring GDB for compilation
4896 For normal use, type ``./configure host''. See README or gdb.texinfo
4899 GDB now handles cross debugging. If you are remotely debugging between
4900 two different machines, type ``./configure host -target=targ''.
4901 Host is the machine where GDB will run; targ is the machine
4902 where the program that you are debugging will run.