1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.3.1
6 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
7 and "show remote hardware-watchpoint-length-limit". These allows to
8 set or show the maximum length limit (in bytes) of a remote
9 target hardware watchpoint.
11 This allows e.g. to use "unlimited" hardware watchpoints with the
12 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
13 watchpoints are slower than real hardware watchpoints but are
14 significantly faster than gdb software watchpoints.
18 ** The register_pretty_printer function in module gdb.printing now takes
19 an optional `replace' argument. If True, the new printer replaces any
22 ** The "maint set python print-stack on|off" command has been
23 deprecated, and a new command: "set python print-stack on|off" has
24 replaced it. Additionally, the default for "print-stack" is now
27 ** A prompt substitution hook (prompt_hook) is now available to the
30 ** A new Python module, gdb.prompt has been added to the GDB Python
31 modules library. This module provides functionality for
32 escape sequences in prompts (used by set/show
33 extended-prompt). These escape sequences are replaced by their
36 ** Python commands and convenience-functions located in
37 'data-directory'/python/gdb/command and
38 'data-directory'/python/gdb/function are now automatically loaded
41 ** Blocks now provide four new attributes. global_block and
42 static_block will return the global and static blocks
43 respectively. is_static and is_global are boolean attributes
44 that indicate if the block is one of those two types.
46 ** Symbols now provide the "type" attribute, the type of the symbol.
48 ** The "gdb.breakpoint" function has been deprecated in favor of
51 ** Type objects for struct and union types now allow access to
52 the fields using standard Python dictionary (mapping) methods.
53 For example, "some_type['myfield']" now works, as does
56 ** A new event "gdb.new_objfile" has been added, triggered by loading a
59 ** A new function, "deep_items" has been added to the gdb.types
60 module in the GDB Python modules library. This function returns
61 an iterator over the fields of a struct or union type. Unlike
62 the standard Python "iteritems" method, it will recursively traverse
65 * libthread-db-search-path now supports two special values: $sdir and $pdir.
66 $sdir specifies the default system locations of shared libraries.
67 $pdir specifies the directory where the libpthread used by the application
70 GDB no longer looks in $sdir and $pdir after it has searched the directories
71 mentioned in libthread-db-search-path. If you want to search those
72 directories, they must be specified in libthread-db-search-path.
73 The default value of libthread-db-search-path on GNU/Linux and Solaris
74 systems is now "$sdir:$pdir".
76 $pdir is not supported by gdbserver, it is currently ignored.
77 $sdir is supported by gdbserver.
79 * New configure option --with-iconv-bin.
80 When using the internationalization support like the one in the GNU C
81 library, GDB will invoke the "iconv" program to get a list of supported
82 character sets. If this program lives in a non-standard location, one can
83 use this option to specify where to find it.
85 * When natively debugging programs on PowerPC BookE processors running
86 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
87 watchpoints, which specify a mask in addition to an address to watch.
88 The mask specifies that some bits of an address (the bits which are
89 reset in the mask) should be ignored when matching the address accessed
90 by the inferior against the watchpoint address. See the "PowerPC Embedded"
91 section in the user manual for more details.
93 * The new option --once causes GDBserver to stop listening for connections once
94 the first connection is made. The listening port used by GDBserver will
95 become available after that.
97 * New commands "info macros", "info definitions",
98 and "alias" have been added.
100 * New function parameters suffix @entry specifies value of function parameter
101 at the time the function got called. Entry values are available only since
106 watch EXPRESSION mask MASK_VALUE
107 The watch command now supports the mask argument which allows creation
108 of masked watchpoints, if the current architecture supports this feature.
110 info auto-load-scripts [REGEXP]
111 This command was formerly named "maintenance print section-scripts".
112 It is now generally useful and is no longer a maintenance-only command.
114 * Tracepoints can now be enabled and disabled at any time after a trace
115 experiment has been started using the standard "enable" and "disable"
116 commands. It is now possible to start a trace experiment with no enabled
117 tracepoints; GDB will display a warning, but will allow the experiment to
118 begin, assuming that tracepoints will be enabled as needed while the trace
125 Set the GDB prompt, and allow escape sequences to be inserted to
126 display miscellaneous information (see 'help set extended-prompt'
127 for the list of sequences). This prompt (and any information
128 accessed through the escape sequences) is updated every time the
131 set print entry-values (both|compact|default|if-needed|no|only|preferred)
132 show print entry-values
133 Set printing of frame argument values at function entry. In some cases
134 GDB can determine the value of function argument which was passed by the
135 function caller, even if the value was modified inside the called function.
137 set debug entry-values
138 show debug entry-values
139 Control display of debugging info for determining frame argument values at
140 function entry and virtual tail call frames.
146 Dynamically enable a tracepoint in a started trace experiment.
150 Dynamically disable a tracepoint in a started trace experiment.
152 * Dcache size (number of lines) and line-size are now runtime-configurable
153 via "set dcache line" and "set dcache line-size" commands.
157 Texas Instruments TMS320C6x tic6x-*-*
159 *** Changes in GDB 7.3.1
161 * The build failure for NetBSD and OpenBSD targets have now been fixed.
163 *** Changes in GDB 7.3
165 * GDB has a new command: "thread find [REGEXP]".
166 It finds the thread id whose name, target id, or thread extra info
167 matches the given regular expression.
169 * The "catch syscall" command now works on mips*-linux* targets.
171 * The -data-disassemble MI command now supports modes 2 and 3 for
172 dumping the instruction opcodes.
174 * New command line options
176 -data-directory DIR Specify DIR as the "data-directory".
177 This is mostly for testing purposes.
179 * The "maint set python auto-load on|off" command has been renamed to
180 "set auto-load-scripts on|off".
182 * GDB has a new command: "set directories".
183 It is like the "dir" command except that it replaces the
184 source path list instead of augmenting it.
186 * GDB now understands thread names.
188 On GNU/Linux, "info threads" will display the thread name as set by
189 prctl or pthread_setname_np.
191 There is also a new command, "thread name", which can be used to
192 assign a name internally for GDB to display.
195 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
196 has been integrated into GDB.
200 ** The function gdb.Write now accepts an optional keyword 'stream'.
201 This keyword, when provided, will direct the output to either
202 stdout, stderr, or GDB's logging output.
204 ** Parameters can now be be sub-classed in Python, and in particular
205 you may implement the get_set_doc and get_show_doc functions.
206 This improves how Parameter set/show documentation is processed
207 and allows for more dynamic content.
209 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
210 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
211 have an is_valid method.
213 ** Breakpoints can now be sub-classed in Python, and in particular
214 you may implement a 'stop' function that is executed each time
215 the inferior reaches that breakpoint.
217 ** New function gdb.lookup_global_symbol looks up a global symbol.
219 ** GDB values in Python are now callable if the value represents a
220 function. For example, if 'some_value' represents a function that
221 takes two integer parameters and returns a value, you can call
222 that function like so:
224 result = some_value (10,20)
226 ** Module gdb.types has been added.
227 It contains a collection of utilities for working with gdb.Types objects:
228 get_basic_type, has_field, make_enum_dict.
230 ** Module gdb.printing has been added.
231 It contains utilities for writing and registering pretty-printers.
232 New classes: PrettyPrinter, SubPrettyPrinter,
233 RegexpCollectionPrettyPrinter.
234 New function: register_pretty_printer.
236 ** New commands "info pretty-printers", "enable pretty-printer" and
237 "disable pretty-printer" have been added.
239 ** gdb.parameter("directories") is now available.
241 ** New function gdb.newest_frame returns the newest frame in the
244 ** The gdb.InferiorThread class has a new "name" attribute. This
245 holds the thread's name.
247 ** Python Support for Inferior events.
248 Python scripts can add observers to be notified of events
249 occurring in the process being debugged.
250 The following events are currently supported:
251 - gdb.events.cont Continue event.
252 - gdb.events.exited Inferior exited event.
253 - gdb.events.stop Signal received, and Breakpoint hit events.
257 ** GDB now puts template parameters in scope when debugging in an
258 instantiation. For example, if you have:
260 template<int X> int func (void) { return X; }
262 then if you step into func<5>, "print X" will show "5". This
263 feature requires proper debuginfo support from the compiler; it
264 was added to GCC 4.5.
266 ** The motion commands "next", "finish", "until", and "advance" now
267 work better when exceptions are thrown. In particular, GDB will
268 no longer lose control of the inferior; instead, the GDB will
269 stop the inferior at the point at which the exception is caught.
270 This functionality requires a change in the exception handling
271 code that was introduced in GCC 4.5.
273 * GDB now follows GCC's rules on accessing volatile objects when
274 reading or writing target state during expression evaluation.
275 One notable difference to prior behavior is that "print x = 0"
276 no longer generates a read of x; the value of the assignment is
277 now always taken directly from the value being assigned.
279 * GDB now has some support for using labels in the program's source in
280 linespecs. For instance, you can use "advance label" to continue
281 execution to a label.
283 * GDB now has support for reading and writing a new .gdb_index
284 section. This section holds a fast index of DWARF debugging
285 information and can be used to greatly speed up GDB startup and
286 operation. See the documentation for `save gdb-index' for details.
288 * The "watch" command now accepts an optional "-location" argument.
289 When used, this causes GDB to watch the memory referred to by the
290 expression. Such a watchpoint is never deleted due to it going out
293 * GDB now supports thread debugging of core dumps on GNU/Linux.
295 GDB now activates thread debugging using the libthread_db library
296 when debugging GNU/Linux core dumps, similarly to when debugging
297 live processes. As a result, when debugging a core dump file, GDB
298 is now able to display pthread_t ids of threads. For example, "info
299 threads" shows the same output as when debugging the process when it
300 was live. In earlier releases, you'd see something like this:
303 * 1 LWP 6780 main () at main.c:10
305 While now you see this:
308 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
310 It is also now possible to inspect TLS variables when debugging core
313 When debugging a core dump generated on a machine other than the one
314 used to run GDB, you may need to point GDB at the correct
315 libthread_db library with the "set libthread-db-search-path"
316 command. See the user manual for more details on this command.
318 * When natively debugging programs on PowerPC BookE processors running
319 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
320 which stop execution of the inferior whenever it executes an instruction
321 at any address within the specified range. See the "PowerPC Embedded"
322 section in the user manual for more details.
324 * New features in the GDB remote stub, GDBserver
326 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
327 and i686 LynxOS (version 5.x).
329 ** GDBserver is now supported on Blackfin Linux.
331 * New native configurations
333 ia64 HP-UX ia64-*-hpux*
337 Analog Devices, Inc. Blackfin Processor bfin-*
339 * Ada task switching is now supported on sparc-elf targets when
340 debugging a program using the Ravenscar Profile. For more information,
341 see the "Tasking Support when using the Ravenscar Profile" section
342 in the GDB user manual.
344 * Guile support was removed.
346 * New features in the GNU simulator
348 ** The --map-info flag lists all known core mappings.
350 ** CFI flashes may be simulated via the "cfi" device.
352 *** Changes in GDB 7.2
354 * Shared library support for remote targets by default
356 When GDB is configured for a generic, non-OS specific target, like
357 for example, --target=arm-eabi or one of the many *-*-elf targets,
358 GDB now queries remote stubs for loaded shared libraries using the
359 `qXfer:libraries:read' packet. Previously, shared library support
360 was always disabled for such configurations.
364 ** Argument Dependent Lookup (ADL)
366 In C++ ADL lookup directs function search to the namespaces of its
367 arguments even if the namespace has not been imported.
377 Here the compiler will search for `foo' in the namespace of 'b'
378 and find A::foo. GDB now supports this. This construct is commonly
379 used in the Standard Template Library for operators.
381 ** Improved User Defined Operator Support
383 In addition to member operators, GDB now supports lookup of operators
384 defined in a namespace and imported with a `using' directive, operators
385 defined in the global scope, operators imported implicitly from an
386 anonymous namespace, and the ADL operators mentioned in the previous
388 GDB now also supports proper overload resolution for all the previously
389 mentioned flavors of operators.
391 ** static const class members
393 Printing of static const class members that are initialized in the
394 class definition has been fixed.
396 * Windows Thread Information Block access.
398 On Windows targets, GDB now supports displaying the Windows Thread
399 Information Block (TIB) structure. This structure is visible either
400 by using the new command `info w32 thread-information-block' or, by
401 dereferencing the new convenience variable named `$_tlb', a
402 thread-specific pointer to the TIB. This feature is also supported
403 when remote debugging using GDBserver.
407 Static tracepoints are calls in the user program into a tracing
408 library. One such library is a port of the LTTng kernel tracer to
409 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
410 When debugging with GDBserver, GDB now supports combining the GDB
411 tracepoint machinery with such libraries. For example: the user can
412 use GDB to probe a static tracepoint marker (a call from the user
413 program into the tracing library) with the new "strace" command (see
414 "New commands" below). This creates a "static tracepoint" in the
415 breakpoint list, that can be manipulated with the same feature set
416 as fast and regular tracepoints. E.g., collect registers, local and
417 global variables, collect trace state variables, and define
418 tracepoint conditions. In addition, the user can collect extra
419 static tracepoint marker specific data, by collecting the new
420 $_sdata internal variable. When analyzing the trace buffer, you can
421 inspect $_sdata like any other variable available to GDB. For more
422 information, see the "Tracepoints" chapter in GDB user manual. New
423 remote packets have been defined to support static tracepoints, see
424 the "New remote packets" section below.
426 * Better reconstruction of tracepoints after disconnected tracing
428 GDB will attempt to download the original source form of tracepoint
429 definitions when starting a trace run, and then will upload these
430 upon reconnection to the target, resulting in a more accurate
431 reconstruction of the tracepoints that are in use on the target.
435 You can now exercise direct control over the ways that GDB can
436 affect your program. For instance, you can disallow the setting of
437 breakpoints, so that the program can run continuously (assuming
438 non-stop mode). In addition, the "observer" variable is available
439 to switch all of the different controls; in observer mode, GDB
440 cannot affect the target's behavior at all, which is useful for
441 tasks like diagnosing live systems in the field.
443 * The new convenience variable $_thread holds the number of the
450 Return the address of the Windows Thread Information Block of a given thread.
454 In response to several of the tracepoint packets, the target may now
455 also respond with a number of intermediate `qRelocInsn' request
456 packets before the final result packet, to have GDB handle
457 relocating an instruction to execute at a different address. This
458 is particularly useful for stubs that support fast tracepoints. GDB
459 reports support for this feature in the qSupported packet.
463 List static tracepoint markers in the target program.
467 List static tracepoint markers at a given address in the target
470 qXfer:statictrace:read
472 Read the static trace data collected (by a `collect $_sdata'
473 tracepoint action). The remote stub reports support for this packet
474 to gdb's qSupported query.
478 Send the current settings of GDB's permission flags.
482 Send part of the source (textual) form of a tracepoint definition,
483 which includes location, conditional, and action list.
485 * The source command now accepts a -s option to force searching for the
486 script in the source search path even if the script name specifies
489 * New features in the GDB remote stub, GDBserver
491 - GDBserver now support tracepoints (including fast tracepoints, and
492 static tracepoints). The feature is currently supported by the
493 i386-linux and amd64-linux builds. See the "Tracepoints support
494 in gdbserver" section in the manual for more information.
496 GDBserver JIT compiles the tracepoint's conditional agent
497 expression bytecode into native code whenever possible for low
498 overhead dynamic tracepoints conditionals. For such tracepoints,
499 an expression that examines program state is evaluated when the
500 tracepoint is reached, in order to determine whether to capture
501 trace data. If the condition is simple and false, processing the
502 tracepoint finishes very quickly and no data is gathered.
504 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
505 for static tracepoints support.
507 - GDBserver now supports x86_64 Windows 64-bit debugging.
509 * GDB now sends xmlRegisters= in qSupported packet to indicate that
510 it understands register description.
512 * The --batch flag now disables pagination and queries.
514 * X86 general purpose registers
516 GDB now supports reading/writing byte, word and double-word x86
517 general purpose registers directly. This means you can use, say,
518 $ah or $ax to refer, respectively, to the byte register AH and
519 16-bit word register AX that are actually portions of the 32-bit
520 register EAX or 64-bit register RAX.
522 * The `commands' command now accepts a range of breakpoints to modify.
523 A plain `commands' following a command that creates multiple
524 breakpoints affects all the breakpoints set by that command. This
525 applies to breakpoints set by `rbreak', and also applies when a
526 single `break' command creates multiple breakpoints (e.g.,
527 breakpoints on overloaded c++ functions).
529 * The `rbreak' command now accepts a filename specification as part of
530 its argument, limiting the functions selected by the regex to those
531 in the specified file.
533 * Support for remote debugging Windows and SymbianOS shared libraries
534 from Unix hosts has been improved. Non Windows GDB builds now can
535 understand target reported file names that follow MS-DOS based file
536 system semantics, such as file names that include drive letters and
537 use the backslash character as directory separator. This makes it
538 possible to transparently use the "set sysroot" and "set
539 solib-search-path" on Unix hosts to point as host copies of the
540 target's shared libraries. See the new command "set
541 target-file-system-kind" described below, and the "Commands to
542 specify files" section in the user manual for more information.
546 eval template, expressions...
547 Convert the values of one or more expressions under the control
548 of the string template to a command line, and call it.
550 set target-file-system-kind unix|dos-based|auto
551 show target-file-system-kind
552 Set or show the assumed file system kind for target reported file
555 save breakpoints <filename>
556 Save all current breakpoint definitions to a file suitable for use
557 in a later debugging session. To read the saved breakpoint
558 definitions, use the `source' command.
560 `save tracepoints' is a new alias for `save-tracepoints'. The latter
563 info static-tracepoint-markers
564 Display information about static tracepoint markers in the target.
566 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
567 Define a static tracepoint by probing a marker at the given
568 function, line, address, or marker ID.
572 Enable and disable observer mode.
574 set may-write-registers on|off
575 set may-write-memory on|off
576 set may-insert-breakpoints on|off
577 set may-insert-tracepoints on|off
578 set may-insert-fast-tracepoints on|off
579 set may-interrupt on|off
580 Set individual permissions for GDB effects on the target. Note that
581 some of these settings can have undesirable or surprising
582 consequences, particularly when changed in the middle of a session.
583 For instance, disabling the writing of memory can prevent
584 breakpoints from being inserted, cause single-stepping to fail, or
585 even crash your program, if you disable after breakpoints have been
586 inserted. However, GDB should not crash.
588 set record memory-query on|off
589 show record memory-query
590 Control whether to stop the inferior if memory changes caused
591 by an instruction cannot be recorded.
596 The disassemble command now supports "start,+length" form of two arguments.
600 ** GDB now provides a new directory location, called the python directory,
601 where Python scripts written for GDB can be installed. The location
602 of that directory is <data-directory>/python, where <data-directory>
603 is the GDB data directory. For more details, see section `Scripting
604 GDB using Python' in the manual.
606 ** The GDB Python API now has access to breakpoints, symbols, symbol
607 tables, program spaces, inferiors, threads and frame's code blocks.
608 Additionally, GDB Parameters can now be created from the API, and
609 manipulated via set/show in the CLI.
611 ** New functions gdb.target_charset, gdb.target_wide_charset,
612 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
614 ** New exception gdb.GdbError.
616 ** Pretty-printers are now also looked up in the current program space.
618 ** Pretty-printers can now be individually enabled and disabled.
620 ** GDB now looks for names of Python scripts to auto-load in a
621 special section named `.debug_gdb_scripts', in addition to looking
622 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
624 * Tracepoint actions were unified with breakpoint commands. In particular,
625 there are no longer differences in "info break" output for breakpoints and
626 tracepoints and the "commands" command can be used for both tracepoints and
631 ARM Symbian arm*-*-symbianelf*
633 * D language support.
634 GDB now supports debugging programs written in the D programming
637 * GDB now supports the extended ptrace interface for PowerPC which is
638 available since Linux kernel version 2.6.34. This automatically enables
639 any hardware breakpoints and additional hardware watchpoints available in
640 the processor. The old ptrace interface exposes just one hardware
641 watchpoint and no hardware breakpoints.
643 * GDB is now able to use the Data Value Compare (DVC) register available on
644 embedded PowerPC processors to implement in hardware simple watchpoint
645 conditions of the form:
647 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
649 This works in native GDB running on Linux kernels with the extended ptrace
650 interface mentioned above.
652 *** Changes in GDB 7.1
658 GDB now supports importing of namespaces in C++. This enables the
659 user to inspect variables from imported namespaces. Support for
660 namepace aliasing has also been added. So, if a namespace is
661 aliased in the current scope (e.g. namepace C=A; ) the user can
662 print variables using the alias (e.g. (gdb) print C::x).
666 All known bugs relating to the printing of virtual base class were
667 fixed. It is now possible to call overloaded static methods using a
672 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
673 and reinterpret_cast<> are now handled by the C++ expression parser.
677 Xilinx MicroBlaze microblaze-*-*
682 Xilinx MicroBlaze microblaze
685 * Multi-program debugging.
687 GDB now has support for multi-program (a.k.a. multi-executable or
688 multi-exec) debugging. This allows for debugging multiple inferiors
689 simultaneously each running a different program under the same GDB
690 session. See "Debugging Multiple Inferiors and Programs" in the
691 manual for more information. This implied some user visible changes
692 in the multi-inferior support. For example, "info inferiors" now
693 lists inferiors that are not running yet or that have exited
694 already. See also "New commands" and "New options" below.
696 * New tracing features
698 GDB's tracepoint facility now includes several new features:
700 ** Trace state variables
702 GDB tracepoints now include support for trace state variables, which
703 are variables managed by the target agent during a tracing
704 experiment. They are useful for tracepoints that trigger each
705 other, so for instance one tracepoint can count hits in a variable,
706 and then a second tracepoint has a condition that is true when the
707 count reaches a particular value. Trace state variables share the
708 $-syntax of GDB convenience variables, and can appear in both
709 tracepoint actions and condition expressions. Use the "tvariable"
710 command to create, and "info tvariables" to view; see "Trace State
711 Variables" in the manual for more detail.
715 GDB now includes an option for defining fast tracepoints, which
716 targets may implement more efficiently, such as by installing a jump
717 into the target agent rather than a trap instruction. The resulting
718 speedup can be by two orders of magnitude or more, although the
719 tradeoff is that some program locations on some target architectures
720 might not allow fast tracepoint installation, for instance if the
721 instruction to be replaced is shorter than the jump. To request a
722 fast tracepoint, use the "ftrace" command, with syntax identical to
723 the regular trace command.
725 ** Disconnected tracing
727 It is now possible to detach GDB from the target while it is running
728 a trace experiment, then reconnect later to see how the experiment
729 is going. In addition, a new variable disconnected-tracing lets you
730 tell the target agent whether to continue running a trace if the
731 connection is lost unexpectedly.
735 GDB now has the ability to save the trace buffer into a file, and
736 then use that file as a target, similarly to you can do with
737 corefiles. You can select trace frames, print data that was
738 collected in them, and use tstatus to display the state of the
739 tracing run at the moment that it was saved. To create a trace
740 file, use "tsave <filename>", and to use it, do "target tfile
743 ** Circular trace buffer
745 You can ask the target agent to handle the trace buffer as a
746 circular buffer, discarding the oldest trace frames to make room for
747 newer ones, by setting circular-trace-buffer to on. This feature may
748 not be available for all target agents.
753 The disassemble command, when invoked with two arguments, now requires
754 the arguments to be comma-separated.
757 The info variables command now displays variable definitions. Files
758 which only declare a variable are not shown.
761 The source command is now capable of sourcing Python scripts.
762 This feature is dependent on the debugger being build with Python
765 Related to this enhancement is also the introduction of a new command
766 "set script-extension" (see below).
768 * New commands (for set/show, see "New options" below)
770 record save [<FILENAME>]
771 Save a file (in core file format) containing the process record
772 execution log for replay debugging at a later time.
774 record restore <FILENAME>
775 Restore the process record execution log that was saved at an
776 earlier time, for replay debugging.
778 add-inferior [-copies <N>] [-exec <FILENAME>]
781 clone-inferior [-copies <N>] [ID]
782 Make a new inferior ready to execute the same program another
788 maint info program-spaces
789 List the program spaces loaded into GDB.
791 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
792 show remote interrupt-sequence
793 Allow the user to select one of ^C, a BREAK signal or BREAK-g
794 as the sequence to the remote target in order to interrupt the execution.
795 Ctrl-C is a default. Some system prefers BREAK which is high level of
796 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
797 Magic SysRq g. It is BREAK signal and character 'g'.
799 set remote interrupt-on-connect [on | off]
800 show remote interrupt-on-connect
801 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
802 remote target when gdb connects to it. This is needed when you debug
805 set remotebreak [on | off]
807 Deprecated. Use "set/show remote interrupt-sequence" instead.
809 tvariable $NAME [ = EXP ]
810 Create or modify a trace state variable.
813 List trace state variables and their values.
815 delete tvariable $NAME ...
816 Delete one or more trace state variables.
819 Evaluate the given expressions without collecting anything into the
820 trace buffer. (Valid in tracepoint actions only.)
822 ftrace FN / FILE:LINE / *ADDR
823 Define a fast tracepoint at the given function, line, or address.
825 * New expression syntax
827 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
828 GDB now parses 0b101010 identically with 42.
832 set follow-exec-mode new|same
833 show follow-exec-mode
834 Control whether GDB reuses the same inferior across an exec call or
835 creates a new one. This is useful to be able to restart the old
836 executable after the inferior having done an exec call.
838 set default-collect EXPR, ...
840 Define a list of expressions to be collected at each tracepoint.
841 This is a useful way to ensure essential items are not overlooked,
842 such as registers or a critical global variable.
844 set disconnected-tracing
845 show disconnected-tracing
846 If set to 1, the target is instructed to continue tracing if it
847 loses its connection to GDB. If 0, the target is to stop tracing
850 set circular-trace-buffer
851 show circular-trace-buffer
852 If set to on, the target is instructed to use a circular trace buffer
853 and discard the oldest trace frames instead of stopping the trace due
854 to a full trace buffer. If set to off, the trace stops when the buffer
855 fills up. Some targets may not support this.
857 set script-extension off|soft|strict
858 show script-extension
859 If set to "off", the debugger does not perform any script language
860 recognition, and all sourced files are assumed to be GDB scripts.
861 If set to "soft" (the default), files are sourced according to
862 filename extension, falling back to GDB scripts if the first
864 If set to "strict", files are sourced according to filename extension.
866 set ada trust-PAD-over-XVS on|off
867 show ada trust-PAD-over-XVS
868 If off, activate a workaround against a bug in the debugging information
869 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
870 the GCC sources for more information about the GNAT encoding and
871 PAD types in particular). It is always safe to set this option to
872 off, but this introduces a slight performance penalty. The default
875 * Python API Improvements
877 ** GDB provides the new class gdb.LazyString. This is useful in
878 some pretty-printing cases. The new method gdb.Value.lazy_string
879 provides a simple way to create objects of this type.
881 ** The fields returned by gdb.Type.fields now have an
882 `is_base_class' attribute.
884 ** The new method gdb.Type.range returns the range of an array type.
886 ** The new method gdb.parse_and_eval can be used to parse and
887 evaluate an expression.
892 Define a trace state variable.
895 Get the current value of a trace state variable.
898 Set desired tracing behavior upon disconnection.
901 Set the trace buffer to be linear or circular.
904 Get data about the tracepoints currently in use.
908 Process record now works correctly with hardware watchpoints.
910 Multiple bug fixes have been made to the mips-irix port, making it
911 much more reliable. In particular:
912 - Debugging threaded applications is now possible again. Previously,
913 GDB would hang while starting the program, or while waiting for
914 the program to stop at a breakpoint.
915 - Attaching to a running process no longer hangs.
916 - An error occurring while loading a core file has been fixed.
917 - Changing the value of the PC register now works again. This fixes
918 problems observed when using the "jump" command, or when calling
919 a function from GDB, or even when assigning a new value to $pc.
920 - With the "finish" and "return" commands, the return value for functions
921 returning a small array is now correctly printed.
922 - It is now possible to break on shared library code which gets executed
923 during a shared library init phase (code executed while executing
924 their .init section). Previously, the breakpoint would have no effect.
925 - GDB is now able to backtrace through the signal handler for
926 non-threaded programs.
928 PIE (Position Independent Executable) programs debugging is now supported.
929 This includes debugging execution of PIC (Position Independent Code) shared
930 libraries although for that, it should be possible to run such libraries as an
933 *** Changes in GDB 7.0
935 * GDB now has an interface for JIT compilation. Applications that
936 dynamically generate code can create symbol files in memory and register
937 them with GDB. For users, the feature should work transparently, and
938 for JIT developers, the interface is documented in the GDB manual in the
939 "JIT Compilation Interface" chapter.
941 * Tracepoints may now be conditional. The syntax is as for
942 breakpoints; either an "if" clause appended to the "trace" command,
943 or the "condition" command is available. GDB sends the condition to
944 the target for evaluation using the same bytecode format as is used
945 for tracepoint actions.
947 * The disassemble command now supports: an optional /r modifier, print the
948 raw instructions in hex as well as in symbolic form, and an optional /m
949 modifier to print mixed source+assembly.
951 * Process record and replay
953 In a architecture environment that supports ``process record and
954 replay'', ``process record and replay'' target can record a log of
955 the process execution, and replay it with both forward and reverse
958 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
959 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
960 set execution-direction {forward|reverse}, for targets that support
963 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
964 feature is available with a native GDB running on kernel version
967 * GDB now has support for multi-byte and wide character sets on the
968 target. Strings whose character type is wchar_t, char16_t, or
969 char32_t are now correctly printed. GDB supports wide- and unicode-
970 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
971 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
972 `printf'. This feature requires iconv to work properly; if your
973 system does not have a working iconv, GDB can use GNU libiconv. See
974 the installation instructions for more information.
976 * GDB now supports automatic retrieval of shared library files from
977 remote targets. To use this feature, specify a system root that begins
978 with the `remote:' prefix, either via the `set sysroot' command or via
979 the `--with-sysroot' configure-time option.
981 * "info sharedlibrary" now takes an optional regex of libraries to show,
982 and it now reports if a shared library has no debugging information.
984 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
985 now complete on file names.
987 * When completing in expressions, gdb will attempt to limit
988 completions to allowable structure or union fields, where appropriate.
989 For instance, consider:
991 # struct example { int f1; double f2; };
992 # struct example variable;
995 If the user types TAB at the end of this command line, the available
996 completions will be "f1" and "f2".
998 * Inlined functions are now supported. They show up in backtraces, and
999 the "step", "next", and "finish" commands handle them automatically.
1001 * GDB now supports the token-splicing (##) and stringification (#)
1002 operators when expanding macros. It also supports variable-arity
1005 * GDB now supports inspecting extra signal information, exported by
1006 the new $_siginfo convenience variable. The feature is currently
1007 implemented on linux ARM, i386 and amd64.
1009 * GDB can now display the VFP floating point registers and NEON vector
1010 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1011 can provide these registers (requires Linux 2.6.30 or later). Remote
1012 and simulator targets may also provide them.
1014 * New remote packets
1017 Search memory for a sequence of bytes.
1020 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1021 operation over reliable transport links. Use of this packet is
1022 controlled by the `set remote noack-packet' command.
1025 Kill the process with the specified process ID. Use this in preference
1026 to `k' when multiprocess protocol extensions are supported.
1029 Obtains additional operating system information
1033 Read or write additional signal information.
1035 * Removed remote protocol undocumented extension
1037 An undocumented extension to the remote protocol's `S' stop reply
1038 packet that permited the stub to pass a process id was removed.
1039 Remote servers should use the `T' stop reply packet instead.
1041 * GDB now supports multiple function calling conventions according to the
1042 DWARF-2 DW_AT_calling_convention function attribute.
1044 * The SH target utilizes the aforementioned change to distinguish between gcc
1045 and Renesas calling convention. It also adds the new CLI commands
1046 `set/show sh calling-convention'.
1048 * GDB can now read compressed debug sections, as produced by GNU gold
1049 with the --compress-debug-sections=zlib flag.
1051 * 64-bit core files are now supported on AIX.
1053 * Thread switching is now supported on Tru64.
1055 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1056 which will be allocated using malloc later in program execution.
1058 * The qXfer:libraries:read remote procotol packet now allows passing a
1059 list of section offsets.
1061 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1062 conditions handling signals delivered during attach or thread creation
1063 have also been fixed.
1065 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1066 From the user's standpoint, all unqualified instances of True and False
1067 are treated as the standard definitions, regardless of context.
1069 * GDB now parses C++ symbol and type names more flexibly. For
1072 template<typename T> class C { };
1075 GDB will now correctly handle all of:
1077 ptype C<char const *>
1078 ptype C<char const*>
1079 ptype C<const char *>
1080 ptype C<const char*>
1082 * New features in the GDB remote stub, gdbserver
1084 - The "--wrapper" command-line argument tells gdbserver to use a
1085 wrapper program to launch programs for debugging.
1087 - On PowerPC and S/390 targets, it is now possible to use a single
1088 gdbserver executable to debug both 32-bit and 64-bit programs.
1089 (This requires gdbserver itself to be built as a 64-bit executable.)
1091 - gdbserver uses the new noack protocol mode for TCP connections to
1092 reduce communications latency, if also supported and enabled in GDB.
1094 - Support for the sparc64-linux-gnu target is now included in
1097 - The amd64-linux build of gdbserver now supports debugging both
1098 32-bit and 64-bit programs.
1100 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1101 now support hardware watchpoints, and will use them automatically
1106 GDB now has support for scripting using Python. Whether this is
1107 available is determined at configure time.
1109 New GDB commands can now be written in Python.
1111 * Ada tasking support
1113 Ada tasks can now be inspected in GDB. The following commands have
1117 Print the list of Ada tasks.
1119 Print detailed information about task number N.
1121 Print the task number of the current task.
1123 Switch the context of debugging to task number N.
1125 * Support for user-defined prefixed commands. The "define" command can
1126 add new commands to existing prefixes, e.g. "target".
1128 * Multi-inferior, multi-process debugging.
1130 GDB now has generalized support for multi-inferior debugging. See
1131 "Debugging Multiple Inferiors" in the manual for more information.
1132 Although availability still depends on target support, the command
1133 set is more uniform now. The GNU/Linux specific multi-forks support
1134 has been migrated to this new framework. This implied some user
1135 visible changes; see "New commands" and also "Removed commands"
1138 * Target descriptions can now describe the target OS ABI. See the
1139 "Target Description Format" section in the user manual for more
1142 * Target descriptions can now describe "compatible" architectures
1143 to indicate that the target can execute applications for a different
1144 architecture in addition to those for the main target architecture.
1145 See the "Target Description Format" section in the user manual for
1148 * Multi-architecture debugging.
1150 GDB now includes general supports for debugging applications on
1151 hybrid systems that use more than one single processor architecture
1152 at the same time. Each such hybrid architecture still requires
1153 specific support to be added. The only hybrid architecture supported
1154 in this version of GDB is the Cell Broadband Engine.
1156 * GDB now supports integrated debugging of Cell/B.E. applications that
1157 use both the PPU and SPU architectures. To enable support for hybrid
1158 Cell/B.E. debugging, you need to configure GDB to support both the
1159 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1160 --enable-targets configure option.
1162 * Non-stop mode debugging.
1164 For some targets, GDB now supports an optional mode of operation in
1165 which you can examine stopped threads while other threads continue
1166 to execute freely. This is referred to as non-stop mode, with the
1167 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1168 section in the user manual for more information.
1170 To be able to support remote non-stop debugging, a remote stub needs
1171 to implement the non-stop mode remote protocol extensions, as
1172 described in the "Remote Non-Stop" section of the user manual. The
1173 GDB remote stub, gdbserver, has been adjusted to support these
1174 extensions on linux targets.
1176 * New commands (for set/show, see "New options" below)
1178 catch syscall [NAME(S) | NUMBER(S)]
1179 Catch system calls. Arguments, which should be names of system
1180 calls or their numbers, mean catch only those syscalls. Without
1181 arguments, every syscall will be caught. When the inferior issues
1182 any of the specified syscalls, GDB will stop and announce the system
1183 call, both when it is called and when its call returns. This
1184 feature is currently available with a native GDB running on the
1185 Linux Kernel, under the following architectures: x86, x86_64,
1186 PowerPC and PowerPC64.
1188 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1190 Search memory for a sequence of bytes.
1192 maint set python print-stack
1193 maint show python print-stack
1194 Show a stack trace when an error is encountered in a Python script.
1197 Invoke CODE by passing it to the Python interpreter.
1202 These allow macros to be defined, undefined, and listed
1206 Show operating system information about processes.
1209 List the inferiors currently under GDB's control.
1212 Switch focus to inferior number NUM.
1215 Detach from inferior number NUM.
1218 Kill inferior number NUM.
1222 set spu stop-on-load
1223 show spu stop-on-load
1224 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1226 set spu auto-flush-cache
1227 show spu auto-flush-cache
1228 Control whether to automatically flush the software-managed cache
1229 during Cell/B.E. debugging.
1231 set sh calling-convention
1232 show sh calling-convention
1233 Control the calling convention used when calling SH target functions.
1236 show debug timestamp
1237 Control display of timestamps with GDB debugging output.
1239 set disassemble-next-line
1240 show disassemble-next-line
1241 Control display of disassembled source lines or instructions when
1244 set remote noack-packet
1245 show remote noack-packet
1246 Set/show the use of remote protocol QStartNoAckMode packet. See above
1247 under "New remote packets."
1249 set remote query-attached-packet
1250 show remote query-attached-packet
1251 Control use of remote protocol `qAttached' (query-attached) packet.
1253 set remote read-siginfo-object
1254 show remote read-siginfo-object
1255 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1258 set remote write-siginfo-object
1259 show remote write-siginfo-object
1260 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1263 set remote reverse-continue
1264 show remote reverse-continue
1265 Control use of remote protocol 'bc' (reverse-continue) packet.
1267 set remote reverse-step
1268 show remote reverse-step
1269 Control use of remote protocol 'bs' (reverse-step) packet.
1271 set displaced-stepping
1272 show displaced-stepping
1273 Control displaced stepping mode. Displaced stepping is a way to
1274 single-step over breakpoints without removing them from the debuggee.
1275 Also known as "out-of-line single-stepping".
1278 show debug displaced
1279 Control display of debugging info for displaced stepping.
1281 maint set internal-error
1282 maint show internal-error
1283 Control what GDB does when an internal error is detected.
1285 maint set internal-warning
1286 maint show internal-warning
1287 Control what GDB does when an internal warning is detected.
1292 Use a wrapper program to launch programs for debugging.
1294 set multiple-symbols (all|ask|cancel)
1295 show multiple-symbols
1296 The value of this variable can be changed to adjust the debugger behavior
1297 when an expression or a breakpoint location contains an ambiguous symbol
1298 name (an overloaded function name, for instance).
1300 set breakpoint always-inserted
1301 show breakpoint always-inserted
1302 Keep breakpoints always inserted in the target, as opposed to inserting
1303 them when resuming the target, and removing them when the target stops.
1304 This option can improve debugger performance on slow remote targets.
1306 set arm fallback-mode (arm|thumb|auto)
1307 show arm fallback-mode
1308 set arm force-mode (arm|thumb|auto)
1310 These commands control how ARM GDB determines whether instructions
1311 are ARM or Thumb. The default for both settings is auto, which uses
1312 the current CPSR value for instructions without symbols; previous
1313 versions of GDB behaved as if "set arm fallback-mode arm".
1315 set disable-randomization
1316 show disable-randomization
1317 Standalone programs run with the virtual address space randomization enabled
1318 by default on some platforms. This option keeps the addresses stable across
1319 multiple debugging sessions.
1323 Control whether other threads are stopped or not when some thread hits
1328 Requests that asynchronous execution is enabled in the target, if available.
1329 In this case, it's possible to resume target in the background, and interact
1330 with GDB while the target is running. "show target-async" displays the
1331 current state of asynchronous execution of the target.
1333 set target-wide-charset
1334 show target-wide-charset
1335 The target-wide-charset is the name of the character set that GDB
1336 uses when printing characters whose type is wchar_t.
1338 set tcp auto-retry (on|off)
1340 set tcp connect-timeout
1341 show tcp connect-timeout
1342 These commands allow GDB to retry failed TCP connections to a remote stub
1343 with a specified timeout period; this is useful if the stub is launched
1344 in parallel with GDB but may not be ready to accept connections immediately.
1346 set libthread-db-search-path
1347 show libthread-db-search-path
1348 Control list of directories which GDB will search for appropriate
1351 set schedule-multiple (on|off)
1352 show schedule-multiple
1353 Allow GDB to resume all threads of all processes or only threads of
1354 the current process.
1358 Use more aggressive caching for accesses to the stack. This improves
1359 performance of remote debugging (particularly backtraces) without
1360 affecting correctness.
1362 set interactive-mode (on|off|auto)
1363 show interactive-mode
1364 Control whether GDB runs in interactive mode (on) or not (off).
1365 When in interactive mode, GDB waits for the user to answer all
1366 queries. Otherwise, GDB does not wait and assumes the default
1367 answer. When set to auto (the default), GDB determines which
1368 mode to use based on the stdin settings.
1373 For program forks, this is replaced by the new more generic `info
1374 inferiors' command. To list checkpoints, you can still use the
1375 `info checkpoints' command, which was an alias for the `info forks'
1379 Replaced by the new `inferior' command. To switch between
1380 checkpoints, you can still use the `restart' command, which was an
1381 alias for the `fork' command.
1384 This is removed, since some targets don't have a notion of
1385 processes. To switch between processes, you can still use the
1386 `inferior' command using GDB's own inferior number.
1389 For program forks, this is replaced by the new more generic `kill
1390 inferior' command. To delete a checkpoint, you can still use the
1391 `delete checkpoint' command, which was an alias for the `delete
1395 For program forks, this is replaced by the new more generic `detach
1396 inferior' command. To detach a checkpoint, you can still use the
1397 `detach checkpoint' command, which was an alias for the `detach
1400 * New native configurations
1402 x86/x86_64 Darwin i[34567]86-*-darwin*
1404 x86_64 MinGW x86_64-*-mingw*
1408 Lattice Mico32 lm32-*
1409 x86 DICOS i[34567]86-*-dicos*
1410 x86_64 DICOS x86_64-*-dicos*
1413 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1414 (mingw32ce) debugging.
1420 These commands were actually not implemented on any target.
1422 *** Changes in GDB 6.8
1424 * New native configurations
1426 NetBSD/hppa hppa*-*netbsd*
1427 Xtensa GNU/Linux xtensa*-*-linux*
1431 NetBSD/hppa hppa*-*-netbsd*
1432 Xtensa GNU/Lunux xtensa*-*-linux*
1434 * Change in command line behavior -- corefiles vs. process ids.
1436 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1437 attaching to process NUMBER fails, GDB no longer attempts to open a
1438 core file named NUMBER. Attaching to a program using the -c option
1439 is no longer supported. Instead, use the '-p' or '--pid' options.
1441 * GDB can now be built as a native debugger for debugging Windows x86
1442 (mingw32) Portable Executable (PE) programs.
1444 * Pending breakpoints no longer change their number when their address
1447 * GDB now supports breakpoints with multiple locations,
1448 including breakpoints on C++ constructors, inside C++ templates,
1449 and in inlined functions.
1451 * GDB's ability to debug optimized code has been improved. GDB more
1452 accurately identifies function bodies and lexical blocks that occupy
1453 more than one contiguous range of addresses.
1455 * Target descriptions can now describe registers for PowerPC.
1457 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1458 registers on PowerPC targets.
1460 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1461 targets even when the libthread_db library is not available.
1463 * The GDB remote stub, gdbserver, now supports the new file transfer
1464 commands (remote put, remote get, and remote delete).
1466 * The GDB remote stub, gdbserver, now supports run and attach in
1467 extended-remote mode.
1469 * hppa*64*-*-hpux11* target broken
1470 The debugger is unable to start a program and fails with the following
1471 error: "Error trying to get information about dynamic linker".
1472 The gdb-6.7 release is also affected.
1474 * GDB now supports the --enable-targets= configure option to allow
1475 building a single GDB executable that supports multiple remote
1476 target architectures.
1478 * GDB now supports debugging C and C++ programs which use the
1479 Decimal Floating Point extension. In addition, the PowerPC target
1480 now has a set of pseudo-registers to inspect decimal float values
1481 stored in two consecutive float registers.
1483 * The -break-insert MI command can optionally create pending
1486 * Improved support for debugging Ada
1487 Many improvements to the Ada language support have been made. These
1489 - Better support for Ada2005 interface types
1490 - Improved handling of arrays and slices in general
1491 - Better support for Taft-amendment types
1492 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1494 - Improved command completion in Ada
1497 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1502 set print frame-arguments (all|scalars|none)
1503 show print frame-arguments
1504 The value of this variable can be changed to control which argument
1505 values should be printed by the debugger when displaying a frame.
1510 Transfer files to and from a remote target, and delete remote files.
1517 Transfer files to and from a remote target, and delete remote files.
1519 * New remote packets
1526 Open, close, read, write, and delete files on the remote system.
1529 Attach to an existing process on the remote system, in extended-remote
1533 Run a new process on the remote system, in extended-remote mode.
1535 *** Changes in GDB 6.7
1537 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1538 bfd, libiberty and opcodes, as revealed by static analysis donated by
1539 Coverity, Inc. (http://scan.coverity.com).
1541 * When looking up multiply-defined global symbols, GDB will now prefer the
1542 symbol definition in the current shared library if it was built using the
1543 -Bsymbolic linker option.
1545 * When the Text User Interface (TUI) is not configured, GDB will now
1546 recognize the -tui command-line option and print a message that the TUI
1549 * The GDB remote stub, gdbserver, now has lower overhead for high
1550 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1552 * GDB for MIPS targets now autodetects whether a remote target provides
1553 32-bit or 64-bit register values.
1555 * Support for C++ member pointers has been improved.
1557 * GDB now understands XML target descriptions, which specify the
1558 target's overall architecture. GDB can read a description from
1559 a local file or over the remote serial protocol.
1561 * Vectors of single-byte data use a new integer type which is not
1562 automatically displayed as character or string data.
1564 * The /s format now works with the print command. It displays
1565 arrays of single-byte integers and pointers to single-byte integers
1568 * Target descriptions can now describe target-specific registers,
1569 for architectures which have implemented the support (currently
1570 only ARM, M68K, and MIPS).
1572 * GDB and the GDB remote stub, gdbserver, now support the XScale
1575 * The GDB remote stub, gdbserver, has been updated to support
1576 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1577 has been rewritten to use the standard GDB remote protocol.
1579 * GDB can now step into C++ functions which are called through thunks.
1581 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1583 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1584 layout. It also supports a TextSeg= and DataSeg= response when only
1585 segment base addresses (rather than offsets) are available.
1587 * The /i format now outputs any trailing branch delay slot instructions
1588 immediately following the last instruction within the count specified.
1590 * The GDB remote protocol "T" stop reply packet now supports a
1591 "library" response. Combined with the new "qXfer:libraries:read"
1592 packet, this response allows GDB to debug shared libraries on targets
1593 where the operating system manages the list of loaded libraries (e.g.
1594 Windows and SymbianOS).
1596 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1597 (DLLs) on Windows and Windows CE targets.
1599 * GDB now supports a faster verification that a .debug file matches its binary
1600 according to its build-id signature, if the signature is present.
1606 Enable or disable hardware flow control (RTS/CTS) on the serial port
1607 when debugging using remote targets.
1609 set mem inaccessible-by-default
1610 show mem inaccessible-by-default
1611 If the target supplies a memory map, for instance via the remote
1612 protocol's "qXfer:memory-map:read" packet, setting this variable
1613 prevents GDB from accessing memory outside the memory map. This
1614 is useful for targets with memory mapped registers or which react
1615 badly to accesses of unmapped address space.
1617 set breakpoint auto-hw
1618 show breakpoint auto-hw
1619 If the target supplies a memory map, for instance via the remote
1620 protocol's "qXfer:memory-map:read" packet, setting this variable
1621 lets GDB use hardware breakpoints automatically for memory regions
1622 where it can not use software breakpoints. This covers both the
1623 "break" command and internal breakpoints used for other commands
1624 including "next" and "finish".
1627 catch exception unhandled
1628 Stop the program execution when Ada exceptions are raised.
1631 Stop the program execution when an Ada assertion failed.
1635 Set an alternate system root for target files. This is a more
1636 general version of "set solib-absolute-prefix", which is now
1637 an alias to "set sysroot".
1640 Provide extended SPU facility status information. This set of
1641 commands is available only when debugging the Cell/B.E. SPU
1644 * New native configurations
1646 OpenBSD/sh sh*-*openbsd*
1649 unset tdesc filename
1651 Use the specified local file as an XML target description, and do
1652 not query the target for its built-in description.
1656 OpenBSD/sh sh*-*-openbsd*
1657 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1658 Toshiba Media Processor mep-elf
1660 * New remote packets
1663 Ignore the specified signals; pass them directly to the debugged program
1664 without stopping other threads or reporting them to GDB.
1666 qXfer:features:read:
1667 Read an XML target description from the target, which describes its
1672 Read or write contents of an spufs file on the target system. These
1673 packets are available only on the Cell/B.E. SPU architecture.
1675 qXfer:libraries:read:
1676 Report the loaded shared libraries. Combined with new "T" packet
1677 response, this packet allows GDB to debug shared libraries on
1678 targets where the operating system manages the list of loaded
1679 libraries (e.g. Windows and SymbianOS).
1683 Support for these obsolete configurations has been removed.
1691 i[34567]86-*-lynxos*
1692 i[34567]86-*-netware*
1693 i[34567]86-*-sco3.2v5*
1694 i[34567]86-*-sco3.2v4*
1696 i[34567]86-*-sysv4.2*
1699 i[34567]86-*-unixware2*
1700 i[34567]86-*-unixware*
1709 * Other removed features
1716 Various m68k-only ROM monitors.
1723 Various Renesas ROM monitors and debugging interfaces for SH and
1728 Support for a Macraigor serial interface to on-chip debugging.
1729 GDB does not directly support the newer parallel or USB
1734 A debug information format. The predecessor to DWARF 2 and
1735 DWARF 3, which are still supported.
1737 Support for the HP aCC compiler on HP-UX/PA-RISC
1739 SOM-encapsulated symbolic debugging information, automatic
1740 invocation of pxdb, and the aCC custom C++ ABI. This does not
1741 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1742 with aCC can still be debugged on an assembly level.
1744 MIPS ".pdr" sections
1746 A MIPS-specific format used to describe stack frame layout
1747 in debugging information.
1751 GDB could work with an older version of Guile to debug
1752 the interpreter and Scheme programs running in it.
1754 set mips stack-arg-size
1755 set mips saved-gpreg-size
1757 Use "set mips abi" to control parameter passing for MIPS.
1759 *** Changes in GDB 6.6
1764 Cell Broadband Engine SPU spu-elf
1766 * GDB can now be configured as a cross-debugger targeting native Windows
1767 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1768 running on a Windows system over TCP/IP to debug Windows programs.
1770 * The GDB remote stub, gdbserver, has been updated to support Windows and
1771 Cygwin debugging. Both single-threaded and multi-threaded programs are
1774 * The "set trust-readonly-sections" command works again. This command was
1775 broken in GDB 6.3, 6.4, and 6.5.
1777 * The "load" command now supports writing to flash memory, if the remote
1778 stub provides the required support.
1780 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1781 longer requires symbolic debug information (e.g. DWARF-2).
1786 unset substitute-path
1787 show substitute-path
1788 Manage a list of substitution rules that GDB uses to rewrite the name
1789 of the directories where the sources are located. This can be useful
1790 for instance when the sources were moved to a different location
1791 between compilation and debugging.
1795 Print each CLI command as it is executed. Each command is prefixed with
1796 a number of `+' symbols representing the nesting depth.
1797 The source command now has a `-v' option to enable the same feature.
1801 The ARM Demon monitor support (RDP protocol, "target rdp").
1803 Kernel Object Display, an embedded debugging feature which only worked with
1804 an obsolete version of Cisco IOS.
1806 The 'set download-write-size' and 'show download-write-size' commands.
1808 * New remote packets
1811 Tell a stub about GDB client features, and request remote target features.
1812 The first feature implemented is PacketSize, which allows the target to
1813 specify the size of packets it can handle - to minimize the number of
1814 packets required and improve performance when connected to a remote
1818 Fetch an OS auxilliary vector from the remote stub. This packet is a
1819 more efficient replacement for qPart:auxv:read.
1821 qXfer:memory-map:read:
1822 Fetch a memory map from the remote stub, including information about
1823 RAM, ROM, and flash memory devices.
1828 Erase and program a flash memory device.
1830 * Removed remote packets
1833 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
1834 used it, and only gdbserver implemented it.
1836 *** Changes in GDB 6.5
1840 Renesas M32C/M16C m32c-elf
1842 Morpho Technologies ms1 ms1-elf
1846 init-if-undefined Initialize a convenience variable, but
1847 only if it doesn't already have a value.
1849 The following commands are presently only implemented for native GNU/Linux:
1851 checkpoint Save a snapshot of the program state.
1853 restart <n> Return the program state to a
1854 previously saved state.
1856 info checkpoints List currently saved checkpoints.
1858 delete-checkpoint <n> Delete a previously saved checkpoint.
1860 set|show detach-on-fork Tell gdb whether to detach from a newly
1861 forked process, or to keep debugging it.
1863 info forks List forks of the user program that
1864 are available to be debugged.
1866 fork <n> Switch to debugging one of several
1867 forks of the user program that are
1868 available to be debugged.
1870 delete-fork <n> Delete a fork from the list of forks
1871 that are available to be debugged (and
1872 kill the forked process).
1874 detach-fork <n> Delete a fork from the list of forks
1875 that are available to be debugged (and
1876 allow the process to continue).
1880 Morpho Technologies ms2 ms1-elf
1882 * Improved Windows host support
1884 GDB now builds as a cross debugger hosted on i686-mingw32, including
1885 native console support, and remote communications using either
1886 network sockets or serial ports.
1888 * Improved Modula-2 language support
1890 GDB can now print most types in the Modula-2 syntax. This includes:
1891 basic types, set types, record types, enumerated types, range types,
1892 pointer types and ARRAY types. Procedure var parameters are correctly
1893 printed and hexadecimal addresses and character constants are also
1894 written in the Modula-2 syntax. Best results can be obtained by using
1895 GNU Modula-2 together with the -gdwarf-2 command line option.
1899 The ARM rdi-share module.
1901 The Netware NLM debug server.
1903 *** Changes in GDB 6.4
1905 * New native configurations
1907 OpenBSD/arm arm*-*-openbsd*
1908 OpenBSD/mips64 mips64-*-openbsd*
1912 Morpho Technologies ms1 ms1-elf
1914 * New command line options
1916 --batch-silent As for --batch, but totally silent.
1917 --return-child-result The debugger will exist with the same value
1918 the child (debugged) program exited with.
1919 --eval-command COMMAND, -ex COMMAND
1920 Execute a single GDB CLI command. This may be
1921 specified multiple times and in conjunction
1922 with the --command (-x) option.
1924 * Deprecated commands removed
1926 The following commands, that were deprecated in 2000, have been
1930 set|show arm disassembly-flavor set|show arm disassembler
1931 othernames set arm disassembler
1932 set|show remotedebug set|show debug remote
1933 set|show archdebug set|show debug arch
1934 set|show eventdebug set|show debug event
1937 * New BSD user-level threads support
1939 It is now possible to debug programs using the user-level threads
1940 library on OpenBSD and FreeBSD. Currently supported (target)
1943 FreeBSD/amd64 x86_64-*-freebsd*
1944 FreeBSD/i386 i386-*-freebsd*
1945 OpenBSD/i386 i386-*-openbsd*
1947 Note that the new kernel threads libraries introduced in FreeBSD 5.x
1948 are not yet supported.
1950 * New support for Matsushita MN10300 w/sim added
1951 (Work in progress). mn10300-elf.
1953 * REMOVED configurations and files
1955 VxWorks and the XDR protocol *-*-vxworks
1956 Motorola MCORE mcore-*-*
1957 National Semiconductor NS32000 ns32k-*-*
1959 * New "set print array-indexes" command
1961 After turning this setting "on", GDB prints the index of each element
1962 when displaying arrays. The default is "off" to preserve the previous
1965 * VAX floating point support
1967 GDB now supports the not-quite-ieee VAX F and D floating point formats.
1969 * User-defined command support
1971 In addition to using $arg0..$arg9 for argument passing, it is now possible
1972 to use $argc to determine now many arguments have been passed. See the
1973 section on user-defined commands in the user manual for more information.
1975 *** Changes in GDB 6.3:
1977 * New command line option
1979 GDB now accepts -l followed by a number to set the timeout for remote
1982 * GDB works with GCC -feliminate-dwarf2-dups
1984 GDB now supports a more compact representation of DWARF-2 debug
1985 information using DW_FORM_ref_addr references. These are produced
1986 by GCC with the option -feliminate-dwarf2-dups and also by some
1987 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
1988 to use -feliminate-dwarf2-dups.
1990 * Internationalization
1992 When supported by the host system, GDB will be built with
1993 internationalization (libintl). The task of marking up the sources is
1994 continued, we're looking forward to our first translation.
1998 Initial support for debugging programs compiled with the GNAT
1999 implementation of the Ada programming language has been integrated
2000 into GDB. In this release, support is limited to expression evaluation.
2002 * New native configurations
2004 GNU/Linux/m32r m32r-*-linux-gnu
2008 GDB's remote protocol now includes support for the 'p' packet. This
2009 packet is used to fetch individual registers from a remote inferior.
2011 * END-OF-LIFE registers[] compatibility module
2013 GDB's internal register infrastructure has been completely rewritten.
2014 The new infrastructure making possible the implementation of key new
2015 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2018 GDB 6.3 will be the last release to include the the registers[]
2019 compatibility module that allowed out-of-date configurations to
2020 continue to work. This change directly impacts the following
2030 powerpc bdm protocol
2032 Unless there is activity to revive these configurations, they will be
2033 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2035 * OBSOLETE configurations and files
2037 Configurations that have been declared obsolete in this release have
2038 been commented out. Unless there is activity to revive these
2039 configurations, the next release of GDB will have their sources
2040 permanently REMOVED.
2049 *** Changes in GDB 6.2.1:
2051 * MIPS `break main; run' gave an heuristic-fence-post warning
2053 When attempting to run even a simple program, a warning about
2054 heuristic-fence-post being hit would be reported. This problem has
2057 * MIPS IRIX 'long double' crashed GDB
2059 When examining a long double variable, GDB would get a segmentation
2060 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2061 IRIX long double values).
2065 A bug in the VAX stack code was causing problems with the "next"
2066 command. This problem has been fixed.
2068 *** Changes in GDB 6.2:
2070 * Fix for ``many threads''
2072 On GNU/Linux systems that use the NPTL threads library, a program
2073 rapidly creating and deleting threads would confuse GDB leading to the
2076 ptrace: No such process.
2077 thread_db_get_info: cannot get thread info: generic error
2079 This problem has been fixed.
2081 * "-async" and "-noasync" options removed.
2083 Support for the broken "-noasync" option has been removed (it caused
2086 * New ``start'' command.
2088 This command runs the program until the begining of the main procedure.
2090 * New BSD Kernel Data Access Library (libkvm) interface
2092 Using ``target kvm'' it is now possible to debug kernel core dumps and
2093 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2094 platforms. Currently supported (native-only) configurations are:
2096 FreeBSD/amd64 x86_64-*-freebsd*
2097 FreeBSD/i386 i?86-*-freebsd*
2098 NetBSD/i386 i?86-*-netbsd*
2099 NetBSD/m68k m68*-*-netbsd*
2100 NetBSD/sparc sparc-*-netbsd*
2101 OpenBSD/amd64 x86_64-*-openbsd*
2102 OpenBSD/i386 i?86-*-openbsd*
2103 OpenBSD/m68k m68*-openbsd*
2104 OpenBSD/sparc sparc-*-openbsd*
2106 * Signal trampoline code overhauled
2108 Many generic problems with GDB's signal handling code have been fixed.
2109 These include: backtraces through non-contiguous stacks; recognition
2110 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2111 call; backtrace through a signal trampoline; step into and out of
2112 signal handlers; and single-stepping in the signal trampoline.
2114 Please note that kernel bugs are a limiting factor here. These
2115 features have been shown to work on an s390 GNU/Linux system that
2116 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2118 * Cygwin support for DWARF 2 added.
2120 * New native configurations
2122 GNU/Linux/hppa hppa*-*-linux*
2123 OpenBSD/hppa hppa*-*-openbsd*
2124 OpenBSD/m68k m68*-*-openbsd*
2125 OpenBSD/m88k m88*-*-openbsd*
2126 OpenBSD/powerpc powerpc-*-openbsd*
2127 NetBSD/vax vax-*-netbsd*
2128 OpenBSD/vax vax-*-openbsd*
2130 * END-OF-LIFE frame compatibility module
2132 GDB's internal frame infrastructure has been completely rewritten.
2133 The new infrastructure making it possible to support key new features
2134 including DWARF 2 Call Frame Information. To aid in the task of
2135 migrating old configurations to this new infrastructure, a
2136 compatibility module, that allowed old configurations to continue to
2137 work, was also included.
2139 GDB 6.2 will be the last release to include this frame compatibility
2140 module. This change directly impacts the following configurations:
2150 Unless there is activity to revive these configurations, they will be
2151 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2153 * REMOVED configurations and files
2155 Sun 3, running SunOS 3 m68*-*-sunos3*
2156 Sun 3, running SunOS 4 m68*-*-sunos4*
2157 Sun 2, running SunOS 3 m68000-*-sunos3*
2158 Sun 2, running SunOS 4 m68000-*-sunos4*
2159 Motorola 680x0 running LynxOS m68*-*-lynxos*
2160 AT&T 3b1/Unix pc m68*-att-*
2161 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2162 decstation mips-dec-* mips-little-*
2163 riscos mips-*-riscos* mips-*-sysv*
2164 sonymips mips-sony-*
2165 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2167 *** Changes in GDB 6.1.1:
2169 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2171 The TUI (Text-mode User Interface) is now built as part of a default
2172 GDB configuration. It is enabled by either selecting the TUI with the
2173 command line option "-i=tui" or by running the separate "gdbtui"
2174 program. For more information on the TUI, see the manual "Debugging
2177 * Pending breakpoint support (also included in GDB 6.1)
2179 Support has been added to allow you to specify breakpoints in shared
2180 libraries that have not yet been loaded. If a breakpoint location
2181 cannot be found, and the "breakpoint pending" option is set to auto,
2182 GDB queries you if you wish to make the breakpoint pending on a future
2183 shared-library load. If and when GDB resolves the breakpoint symbol,
2184 the pending breakpoint is removed as one or more regular breakpoints
2187 Pending breakpoints are very useful for GCJ Java debugging.
2189 * Fixed ISO-C build problems
2191 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2192 non ISO-C code that stopped them being built using a more strict ISO-C
2193 compiler (e.g., IBM's C compiler).
2195 * Fixed build problem on IRIX 5
2197 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2198 wasn't able to compile compile on an IRIX 5 system.
2200 * Added execute permission to gdb/gdbserver/configure
2202 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2203 permission. This bug would cause configure to fail on a number of
2204 systems (Solaris, IRIX). Ref: server/519.
2206 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2208 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2209 has been updated to use constant array sizes.
2211 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2213 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2214 its generated DWARF Call Frame Info. This encoding was causing GDB to
2215 panic, that panic has been fixed. Ref: gdb/1628.
2217 * Fixed a problem when examining parameters in shared library code.
2219 When examining parameters in optimized shared library code generated
2220 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2221 not available''. GDB now correctly displays the variable's value.
2223 *** Changes in GDB 6.1:
2225 * Removed --with-mmalloc
2227 Support for the mmalloc memory manager has been removed, as it
2228 conflicted with the internal gdb byte cache.
2230 * Changes in AMD64 configurations
2232 The AMD64 target now includes the %cs and %ss registers. As a result
2233 the AMD64 remote protocol has changed; this affects the floating-point
2234 and SSE registers. If you rely on those registers for your debugging,
2235 you should upgrade gdbserver on the remote side.
2237 * Revised SPARC target
2239 The SPARC target has been completely revised, incorporating the
2240 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2241 support for LynxOS and SunOS 4 has been dropped. Calling functions
2242 from within GDB on operating systems with a non-executable stack
2243 (Solaris, OpenBSD) now works.
2247 GDB has a new C++ demangler which does a better job on the mangled
2248 names generated by current versions of g++. It also runs faster, so
2249 with this and other changes gdb should now start faster on large C++
2252 * DWARF 2 Location Expressions
2254 GDB support for location expressions has been extended to support function
2255 arguments and frame bases. Older versions of GDB could crash when they
2258 * C++ nested types and namespaces
2260 GDB's support for nested types and namespaces in C++ has been
2261 improved, especially if you use the DWARF 2 debugging format. (This
2262 is the default for recent versions of GCC on most platforms.)
2263 Specifically, if you have a class "Inner" defined within a class or
2264 namespace "Outer", then GDB realizes that the class's name is
2265 "Outer::Inner", not simply "Inner". This should greatly reduce the
2266 frequency of complaints about not finding RTTI symbols. In addition,
2267 if you are stopped at inside of a function defined within a namespace,
2268 GDB modifies its name lookup accordingly.
2270 * New native configurations
2272 NetBSD/amd64 x86_64-*-netbsd*
2273 OpenBSD/amd64 x86_64-*-openbsd*
2274 OpenBSD/alpha alpha*-*-openbsd*
2275 OpenBSD/sparc sparc-*-openbsd*
2276 OpenBSD/sparc64 sparc64-*-openbsd*
2278 * New debugging protocols
2280 M32R with SDI protocol m32r-*-elf*
2282 * "set prompt-escape-char" command deleted.
2284 The command "set prompt-escape-char" has been deleted. This command,
2285 and its very obscure effet on GDB's prompt, was never documented,
2286 tested, nor mentioned in the NEWS file.
2288 * OBSOLETE configurations and files
2290 Configurations that have been declared obsolete in this release have
2291 been commented out. Unless there is activity to revive these
2292 configurations, the next release of GDB will have their sources
2293 permanently REMOVED.
2295 Sun 3, running SunOS 3 m68*-*-sunos3*
2296 Sun 3, running SunOS 4 m68*-*-sunos4*
2297 Sun 2, running SunOS 3 m68000-*-sunos3*
2298 Sun 2, running SunOS 4 m68000-*-sunos4*
2299 Motorola 680x0 running LynxOS m68*-*-lynxos*
2300 AT&T 3b1/Unix pc m68*-att-*
2301 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2302 decstation mips-dec-* mips-little-*
2303 riscos mips-*-riscos* mips-*-sysv*
2304 sonymips mips-sony-*
2305 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2307 * REMOVED configurations and files
2309 SGI Irix-4.x mips-sgi-irix4 or iris4
2310 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2311 Z8000 simulator z8k-zilog-none or z8ksim
2312 Matsushita MN10200 w/simulator mn10200-*-*
2313 H8/500 simulator h8500-hitachi-hms or h8500hms
2314 HP/PA running BSD hppa*-*-bsd*
2315 HP/PA running OSF/1 hppa*-*-osf*
2316 HP/PA Pro target hppa*-*-pro*
2317 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2318 386BSD i[3456]86-*-bsd*
2319 Sequent family i[3456]86-sequent-sysv4*
2320 i[3456]86-sequent-sysv*
2321 i[3456]86-sequent-bsd*
2322 SPARC running LynxOS sparc-*-lynxos*
2323 SPARC running SunOS 4 sparc-*-sunos4*
2324 Tsqware Sparclet sparclet-*-*
2325 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2327 *** Changes in GDB 6.0:
2331 Support for debugging the Objective-C programming language has been
2332 integrated into GDB.
2334 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2336 DWARF 2's Call Frame Information makes available compiler generated
2337 information that more exactly describes the program's run-time stack.
2338 By using this information, GDB is able to provide more robust stack
2341 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2342 have been updated to use a new backtrace mechanism which includes
2343 DWARF 2 CFI support.
2347 GDB's remote protocol has been extended to include support for hosted
2348 file I/O (where the remote target uses GDB's file system). See GDB's
2349 remote protocol documentation for details.
2351 * All targets using the new architecture framework.
2353 All of GDB's targets have been updated to use the new internal
2354 architecture framework. The way is now open for future GDB releases
2355 to include cross-architecture native debugging support (i386 on amd64,
2358 * GNU/Linux's Thread Local Storage (TLS)
2360 GDB now includes support for for the GNU/Linux implementation of
2361 per-thread variables.
2363 * GNU/Linux's Native POSIX Thread Library (NPTL)
2365 GDB's thread code has been updated to work with either the new
2366 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2368 * Separate debug info.
2370 GDB, in conjunction with BINUTILS, now supports a mechanism for
2371 automatically loading debug information from a separate file. Instead
2372 of shipping full debug and non-debug versions of system libraries,
2373 system integrators can now instead ship just the stripped libraries
2374 and optional debug files.
2376 * DWARF 2 Location Expressions
2378 DWARF 2 Location Expressions allow the compiler to more completely
2379 describe the location of variables (even in optimized code) to the
2382 GDB now includes preliminary support for location expressions (support
2383 for DW_OP_piece is still missing).
2387 A number of long standing bugs that caused GDB to die while starting a
2388 Java application have been fixed. GDB's Java support is now
2389 considered "useable".
2391 * GNU/Linux support for fork, vfork, and exec.
2393 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2394 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2397 * GDB supports logging output to a file
2399 There are two new commands, "set logging" and "show logging", which can be
2400 used to capture GDB's output to a file.
2402 * The meaning of "detach" has changed for gdbserver
2404 The "detach" command will now resume the application, as documented. To
2405 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2408 * d10v, m68hc11 `regs' command deprecated
2410 The `info registers' command has been updated so that it displays the
2411 registers using a format identical to the old `regs' command.
2415 A new command, "maint set profile on/off", has been added. This command can
2416 be used to enable or disable profiling while running GDB, to profile a
2417 session or a set of commands. In addition there is a new configure switch,
2418 "--enable-profiling", which will cause GDB to be compiled with profiling
2419 data, for more informative profiling results.
2421 * Default MI syntax changed to "mi2".
2423 The default MI (machine interface) syntax, enabled by the command line
2424 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2425 "mi1", can be enabled by specifying the option "-i=mi1".
2427 Support for the original "mi0" syntax (included in GDB 5.0) has been
2430 Fix for gdb/192: removed extraneous space when displaying frame level.
2431 Fix for gdb/672: update changelist is now output in mi list format.
2432 Fix for gdb/702: a -var-assign that updates the value now shows up
2433 in a subsequent -var-update.
2435 * New native configurations.
2437 FreeBSD/amd64 x86_64-*-freebsd*
2439 * Multi-arched targets.
2441 HP/PA HPUX11 hppa*-*-hpux*
2442 Renesas M32R/D w/simulator m32r-*-elf*
2444 * OBSOLETE configurations and files
2446 Configurations that have been declared obsolete in this release have
2447 been commented out. Unless there is activity to revive these
2448 configurations, the next release of GDB will have their sources
2449 permanently REMOVED.
2451 Z8000 simulator z8k-zilog-none or z8ksim
2452 Matsushita MN10200 w/simulator mn10200-*-*
2453 H8/500 simulator h8500-hitachi-hms or h8500hms
2454 HP/PA running BSD hppa*-*-bsd*
2455 HP/PA running OSF/1 hppa*-*-osf*
2456 HP/PA Pro target hppa*-*-pro*
2457 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2458 Sequent family i[3456]86-sequent-sysv4*
2459 i[3456]86-sequent-sysv*
2460 i[3456]86-sequent-bsd*
2461 Tsqware Sparclet sparclet-*-*
2462 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2464 * REMOVED configurations and files
2467 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2468 IBM AIX PS/2 i[3456]86-*-aix
2469 i386 running Mach 3.0 i[3456]86-*-mach3*
2470 i386 running Mach i[3456]86-*-mach*
2471 i386 running OSF/1 i[3456]86-*osf1mk*
2472 HP/Apollo 68k Family m68*-apollo*-sysv*,
2474 m68*-hp-bsd*, m68*-hp-hpux*
2475 Argonaut Risc Chip (ARC) arc-*-*
2476 Mitsubishi D30V d30v-*-*
2477 Fujitsu FR30 fr30-*-elf*
2478 OS/9000 i[34]86-*-os9k
2479 I960 with MON960 i960-*-coff
2481 * MIPS $fp behavior changed
2483 The convenience variable $fp, for the MIPS, now consistently returns
2484 the address of the current frame's base. Previously, depending on the
2485 context, $fp could refer to either $sp or the current frame's base
2486 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2487 The GNU Source-Level Debugger''.
2489 *** Changes in GDB 5.3:
2491 * GNU/Linux shared library multi-threaded performance improved.
2493 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2494 `/proc', in preference to `ptrace' for memory reads. This may result
2495 in an improvement in the start-up time of multi-threaded, shared
2496 library applications when run under GDB. One GDB user writes: ``loads
2497 shared libs like mad''.
2499 * ``gdbserver'' now supports multi-threaded applications on some targets
2501 Support for debugging multi-threaded applications which use
2502 the GNU/Linux LinuxThreads package has been added for
2503 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2504 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2506 * GDB now supports C/C++ preprocessor macros.
2508 GDB now expands preprocessor macro invocations in C/C++ expressions,
2509 and provides various commands for showing macro definitions and how
2512 The new command `macro expand EXPRESSION' expands any macro
2513 invocations in expression, and shows the result.
2515 The new command `show macro MACRO-NAME' shows the definition of the
2516 macro named MACRO-NAME, and where it was defined.
2518 Most compilers don't include information about macros in the debugging
2519 information by default. In GCC 3.1, for example, you need to compile
2520 your program with the options `-gdwarf-2 -g3'. If the macro
2521 information is present in the executable, GDB will read it.
2523 * Multi-arched targets.
2525 DEC Alpha (partial) alpha*-*-*
2526 DEC VAX (partial) vax-*-*
2528 National Semiconductor NS32000 (partial) ns32k-*-*
2529 Motorola 68000 (partial) m68k-*-*
2530 Motorola MCORE mcore-*-*
2534 Fujitsu FRV architecture added by Red Hat frv*-*-*
2537 * New native configurations
2539 Alpha NetBSD alpha*-*-netbsd*
2540 SH NetBSD sh*-*-netbsdelf*
2541 MIPS NetBSD mips*-*-netbsd*
2542 UltraSPARC NetBSD sparc64-*-netbsd*
2544 * OBSOLETE configurations and files
2546 Configurations that have been declared obsolete in this release have
2547 been commented out. Unless there is activity to revive these
2548 configurations, the next release of GDB will have their sources
2549 permanently REMOVED.
2551 Mitsubishi D30V d30v-*-*
2552 OS/9000 i[34]86-*-os9k
2553 IBM AIX PS/2 i[3456]86-*-aix
2554 Fujitsu FR30 fr30-*-elf*
2555 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2556 Argonaut Risc Chip (ARC) arc-*-*
2557 i386 running Mach 3.0 i[3456]86-*-mach3*
2558 i386 running Mach i[3456]86-*-mach*
2559 i386 running OSF/1 i[3456]86-*osf1mk*
2560 HP/Apollo 68k Family m68*-apollo*-sysv*,
2562 m68*-hp-bsd*, m68*-hp-hpux*
2563 I960 with MON960 i960-*-coff
2565 * OBSOLETE languages
2567 CHILL, a Pascal like language used by telecommunications companies.
2569 * REMOVED configurations and files
2571 AMD 29k family via UDI a29k-amd-udi, udi29k
2572 A29K VxWorks a29k-*-vxworks
2573 AMD 29000 embedded, using EBMON a29k-none-none
2574 AMD 29000 embedded with COFF a29k-none-coff
2575 AMD 29000 embedded with a.out a29k-none-aout
2577 testsuite/gdb.hp/gdb.threads-hp/ directory
2579 * New command "set max-user-call-depth <nnn>"
2581 This command allows the user to limit the call depth of user-defined
2582 commands. The default is 1024.
2584 * Changes in FreeBSD/i386 native debugging.
2586 Support for the "generate-core-file" has been added.
2588 * New commands "dump", "append", and "restore".
2590 These commands allow data to be copied from target memory
2591 to a bfd-format or binary file (dump and append), and back
2592 from a file into memory (restore).
2594 * Improved "next/step" support on multi-processor Alpha Tru64.
2596 The previous single-step mechanism could cause unpredictable problems,
2597 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2598 of a software single-step mechanism prevents this.
2600 *** Changes in GDB 5.2.1:
2608 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2609 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2610 Fix, by Joel Brobecker imported from mainline.
2612 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2613 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2614 Fix, by Fred Fish, imported from mainline.
2616 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2617 Surprisingly enough, it works now.
2618 By Michal Ludvig, imported from mainline.
2620 i386 hardware watchpoint support:
2621 avoid misses on second run for some targets.
2622 By Pierre Muller, imported from mainline.
2624 *** Changes in GDB 5.2:
2626 * New command "set trust-readonly-sections on[off]".
2628 This command is a hint that tells gdb that read-only sections
2629 really are read-only (ie. that their contents will not change).
2630 In this mode, gdb will go to the object file rather than the
2631 target to read memory from read-only sections (such as ".text").
2632 This can be a significant performance improvement on some
2633 (notably embedded) targets.
2635 * New command "generate-core-file" (or "gcore").
2637 This new gdb command allows the user to drop a core file of the child
2638 process state at any time. So far it's been implemented only for
2639 GNU/Linux and Solaris, but should be relatively easily ported to other
2640 hosts. Argument is core file name (defaults to core.<pid>).
2642 * New command line option
2644 GDB now accepts --pid or -p followed by a process id.
2646 * Change in command line behavior -- corefiles vs. process ids.
2648 There is a subtle behavior in the way in which GDB handles
2649 command line arguments. The first non-flag argument is always
2650 a program to debug, but the second non-flag argument may either
2651 be a corefile or a process id. Previously, GDB would attempt to
2652 open the second argument as a corefile, and if that failed, would
2653 issue a superfluous error message and then attempt to attach it as
2654 a process. Now, if the second argument begins with a non-digit,
2655 it will be treated as a corefile. If it begins with a digit,
2656 GDB will attempt to attach it as a process, and if no such process
2657 is found, will then attempt to open it as a corefile.
2659 * Changes in ARM configurations.
2661 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2662 configuration is fully multi-arch.
2664 * New native configurations
2666 ARM NetBSD arm*-*-netbsd*
2667 x86 OpenBSD i[3456]86-*-openbsd*
2668 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2669 Sparc64 running FreeBSD sparc64-*-freebsd*
2673 Sanyo XStormy16 xstormy16-elf
2675 * OBSOLETE configurations and files
2677 Configurations that have been declared obsolete in this release have
2678 been commented out. Unless there is activity to revive these
2679 configurations, the next release of GDB will have their sources
2680 permanently REMOVED.
2682 AMD 29k family via UDI a29k-amd-udi, udi29k
2683 A29K VxWorks a29k-*-vxworks
2684 AMD 29000 embedded, using EBMON a29k-none-none
2685 AMD 29000 embedded with COFF a29k-none-coff
2686 AMD 29000 embedded with a.out a29k-none-aout
2688 testsuite/gdb.hp/gdb.threads-hp/ directory
2690 * REMOVED configurations and files
2692 TI TMS320C80 tic80-*-*
2694 PowerPC Solaris powerpcle-*-solaris*
2695 PowerPC Windows NT powerpcle-*-cygwin32
2696 PowerPC Netware powerpc-*-netware*
2697 Harris/CXUX m88k m88*-harris-cxux*
2698 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2699 ns32k-utek-sysv* ns32k-utek-*
2700 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2701 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2702 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2703 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2704 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2706 * Changes to command line processing
2708 The new `--args' feature can be used to specify command-line arguments
2709 for the inferior from gdb's command line.
2711 * Changes to key bindings
2713 There is a new `operate-and-get-next' function bound to `C-o'.
2715 *** Changes in GDB 5.1.1
2717 Fix compile problem on DJGPP.
2719 Fix a problem with floating-point registers on the i386 being
2722 Fix to stop GDB crashing on .debug_str debug info.
2724 Numerous documentation fixes.
2726 Numerous testsuite fixes.
2728 *** Changes in GDB 5.1:
2730 * New native configurations
2732 Alpha FreeBSD alpha*-*-freebsd*
2733 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2734 MIPS GNU/Linux mips*-*-linux*
2735 MIPS SGI Irix 6.x mips*-sgi-irix6*
2736 ia64 AIX ia64-*-aix*
2737 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2741 Motorola 68HC11 and 68HC12 m68hc11-elf
2743 UltraSparc running GNU/Linux sparc64-*-linux*
2745 * OBSOLETE configurations and files
2747 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2748 Harris/CXUX m88k m88*-harris-cxux*
2749 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2750 ns32k-utek-sysv* ns32k-utek-*
2751 TI TMS320C80 tic80-*-*
2753 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2754 PowerPC Solaris powerpcle-*-solaris*
2755 PowerPC Windows NT powerpcle-*-cygwin32
2756 PowerPC Netware powerpc-*-netware*
2757 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2758 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2759 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2760 Apple Macintosh (MPW) host N/A
2762 stuff.c (Program to stuff files into a specially prepared space in kdb)
2763 kdb-start.c (Main loop for the standalone kernel debugger)
2765 Configurations that have been declared obsolete in this release have
2766 been commented out. Unless there is activity to revive these
2767 configurations, the next release of GDB will have their sources
2768 permanently REMOVED.
2770 * REMOVED configurations and files
2772 Altos 3068 m68*-altos-*
2773 Convex c1-*-*, c2-*-*
2775 ARM RISCix arm-*-* (as host)
2779 * GDB has been converted to ISO C.
2781 GDB's source code has been converted to ISO C. In particular, the
2782 sources are fully protoized, and rely on standard headers being
2787 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2789 * The MI enabled by default.
2791 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2792 revised and enabled by default. Packages which use GDB as a debugging
2793 engine behind a UI or another front end are encouraged to switch to
2794 using the GDB/MI interface, instead of the old annotations interface
2795 which is now deprecated.
2797 * Support for debugging Pascal programs.
2799 GDB now includes support for debugging Pascal programs. The following
2800 main features are supported:
2802 - Pascal-specific data types such as sets;
2804 - automatic recognition of Pascal sources based on file-name
2807 - Pascal-style display of data types, variables, and functions;
2809 - a Pascal expression parser.
2811 However, some important features are not yet supported.
2813 - Pascal string operations are not supported at all;
2815 - there are some problems with boolean types;
2817 - Pascal type hexadecimal constants are not supported
2818 because they conflict with the internal variables format;
2820 - support for Pascal objects and classes is not full yet;
2822 - unlike Pascal, GDB is case-sensitive for symbol names.
2824 * Changes in completion.
2826 Commands such as `shell', `run' and `set args', which pass arguments
2827 to inferior programs, now complete on file names, similar to what
2828 users expect at the shell prompt.
2830 Commands which accept locations, such as `disassemble', `print',
2831 `breakpoint', `until', etc. now complete on filenames as well as
2832 program symbols. Thus, if you type "break foob TAB", and the source
2833 files linked into the programs include `foobar.c', that file name will
2834 be one of the candidates for completion. However, file names are not
2835 considered for completion after you typed a colon that delimits a file
2836 name from a name of a function in that file, as in "break foo.c:bar".
2838 `set demangle-style' completes on available demangling styles.
2840 * New platform-independent commands:
2842 It is now possible to define a post-hook for a command as well as a
2843 hook that runs before the command. For more details, see the
2844 documentation of `hookpost' in the GDB manual.
2846 * Changes in GNU/Linux native debugging.
2848 Support for debugging multi-threaded programs has been completely
2849 revised for all platforms except m68k and sparc. You can now debug as
2850 many threads as your system allows you to have.
2852 Attach/detach is supported for multi-threaded programs.
2854 Support for SSE registers was added for x86. This doesn't work for
2855 multi-threaded programs though.
2857 * Changes in MIPS configurations.
2859 Multi-arch support is enabled for all MIPS configurations.
2861 GDB can now be built as native debugger on SGI Irix 6.x systems for
2862 debugging n32 executables. (Debugging 64-bit executables is not yet
2865 * Unified support for hardware watchpoints in all x86 configurations.
2867 Most (if not all) native x86 configurations support hardware-assisted
2868 breakpoints and watchpoints in a unified manner. This support
2869 implements debug register sharing between watchpoints, which allows to
2870 put a virtually infinite number of watchpoints on the same address,
2871 and also supports watching regions up to 16 bytes with several debug
2874 The new maintenance command `maintenance show-debug-regs' toggles
2875 debugging print-outs in functions that insert, remove, and test
2876 watchpoints and hardware breakpoints.
2878 * Changes in the DJGPP native configuration.
2880 New command ``info dos sysinfo'' displays assorted information about
2881 the CPU, OS, memory, and DPMI server.
2883 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
2884 display information about segment descriptors stored in GDT, LDT, and
2887 New commands ``info dos pde'' and ``info dos pte'' display entries
2888 from Page Directory and Page Tables (for now works with CWSDPMI only).
2889 New command ``info dos address-pte'' displays the Page Table entry for
2890 a given linear address.
2892 GDB can now pass command lines longer than 126 characters to the
2893 program being debugged (requires an update to the libdbg.a library
2894 which is part of the DJGPP development kit).
2896 DWARF2 debug info is now supported.
2898 It is now possible to `step' and `next' through calls to `longjmp'.
2900 * Changes in documentation.
2902 All GDB documentation was converted to GFDL, the GNU Free
2903 Documentation License.
2905 Tracepoints-related commands are now fully documented in the GDB
2908 TUI, the Text-mode User Interface, is now documented in the manual.
2910 Tracepoints-related commands are now fully documented in the GDB
2913 The "GDB Internals" manual now has an index. It also includes
2914 documentation of `ui_out' functions, GDB coding standards, x86
2915 hardware watchpoints, and memory region attributes.
2917 * GDB's version number moved to ``version.in''
2919 The Makefile variable VERSION has been replaced by the file
2920 ``version.in''. People creating GDB distributions should update the
2921 contents of this file.
2925 GUD support is now a standard part of the EMACS distribution.
2927 *** Changes in GDB 5.0:
2929 * Improved support for debugging FP programs on x86 targets
2931 Unified and much-improved support for debugging floating-point
2932 programs on all x86 targets. In particular, ``info float'' now
2933 displays the FP registers in the same format on all x86 targets, with
2934 greater level of detail.
2936 * Improvements and bugfixes in hardware-assisted watchpoints
2938 It is now possible to watch array elements, struct members, and
2939 bitfields with hardware-assisted watchpoints. Data-read watchpoints
2940 on x86 targets no longer erroneously trigger when the address is
2943 * Improvements in the native DJGPP version of GDB
2945 The distribution now includes all the scripts and auxiliary files
2946 necessary to build the native DJGPP version on MS-DOS/MS-Windows
2947 machines ``out of the box''.
2949 The DJGPP version can now debug programs that use signals. It is
2950 possible to catch signals that happened in the debuggee, deliver
2951 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
2952 would kill the program being debugged.) Programs that hook hardware
2953 interrupts (keyboard, timer, etc.) can also be debugged.
2955 It is now possible to debug DJGPP programs that redirect their
2956 standard handles or switch them to raw (as opposed to cooked) mode, or
2957 even close them. The command ``run < foo > bar'' works as expected,
2958 and ``info terminal'' reports useful information about the debuggee's
2959 terminal, including raw/cooked mode, redirection, etc.
2961 The DJGPP version now uses termios functions for console I/O, which
2962 enables debugging graphics programs. Interrupting GDB with Ctrl-C
2965 DOS-style file names with drive letters are now fully supported by
2968 It is now possible to debug DJGPP programs that switch their working
2969 directory. It is also possible to rerun the debuggee any number of
2970 times without restarting GDB; thus, you can use the same setup,
2971 breakpoints, etc. for many debugging sessions.
2973 * New native configurations
2975 ARM GNU/Linux arm*-*-linux*
2976 PowerPC GNU/Linux powerpc-*-linux*
2980 Motorola MCore mcore-*-*
2981 x86 VxWorks i[3456]86-*-vxworks*
2982 PowerPC VxWorks powerpc-*-vxworks*
2983 TI TMS320C80 tic80-*-*
2985 * OBSOLETE configurations
2987 Altos 3068 m68*-altos-*
2988 Convex c1-*-*, c2-*-*
2990 ARM RISCix arm-*-* (as host)
2993 Configurations that have been declared obsolete will be commented out,
2994 but the code will be left in place. If there is no activity to revive
2995 these configurations before the next release of GDB, the sources will
2996 be permanently REMOVED.
2998 * Gould support removed
3000 Support for the Gould PowerNode and NP1 has been removed.
3002 * New features for SVR4
3004 On SVR4 native platforms (such as Solaris), if you attach to a process
3005 without first loading a symbol file, GDB will now attempt to locate and
3006 load symbols from the running process's executable file.
3008 * Many C++ enhancements
3010 C++ support has been greatly improved. Overload resolution now works properly
3011 in almost all cases. RTTI support is on the way.
3013 * Remote targets can connect to a sub-program
3015 A popen(3) style serial-device has been added. This device starts a
3016 sub-process (such as a stand-alone simulator) and then communicates
3017 with that. The sub-program to run is specified using the syntax
3018 ``|<program> <args>'' vis:
3020 (gdb) set remotedebug 1
3021 (gdb) target extended-remote |mn10300-elf-sim program-args
3023 * MIPS 64 remote protocol
3025 A long standing bug in the mips64 remote protocol where by GDB
3026 expected certain 32 bit registers (ex SR) to be transfered as 32
3027 instead of 64 bits has been fixed.
3029 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3030 added to provide backward compatibility with older versions of GDB.
3032 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3034 The command ``set remotebinarydownload'' command has been replaced by
3035 ``set remote X-packet''. Other commands in ``set remote'' family
3036 include ``set remote P-packet''.
3038 * Breakpoint commands accept ranges.
3040 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3041 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3042 ``tracepoint passcount'' also accepts a range of tracepoints.
3044 * ``apropos'' command added.
3046 The ``apropos'' command searches through command names and
3047 documentation strings, printing out matches, making it much easier to
3048 try to find a command that does what you are looking for.
3052 A new machine oriented interface (MI) has been added to GDB. This
3053 interface is designed for debug environments running GDB as a separate
3054 process. This is part of the long term libGDB project. See the
3055 "GDB/MI" chapter of the GDB manual for further information. It can be
3056 enabled by configuring with:
3058 .../configure --enable-gdbmi
3060 *** Changes in GDB-4.18:
3062 * New native configurations
3064 HP-UX 10.20 hppa*-*-hpux10.20
3065 HP-UX 11.x hppa*-*-hpux11.0*
3066 M68K GNU/Linux m68*-*-linux*
3070 Fujitsu FR30 fr30-*-elf*
3071 Intel StrongARM strongarm-*-*
3072 Mitsubishi D30V d30v-*-*
3074 * OBSOLETE configurations
3076 Gould PowerNode, NP1 np1-*-*, pn-*-*
3078 Configurations that have been declared obsolete will be commented out,
3079 but the code will be left in place. If there is no activity to revive
3080 these configurations before the next release of GDB, the sources will
3081 be permanently REMOVED.
3085 As a compatibility experiment, GDB's source files buildsym.h and
3086 buildsym.c have been converted to pure standard C, no longer
3087 containing any K&R compatibility code. We believe that all systems in
3088 use today either come with a standard C compiler, or have a GCC port
3089 available. If this is not true, please report the affected
3090 configuration to bug-gdb@gnu.org immediately. See the README file for
3091 information about getting a standard C compiler if you don't have one
3096 GDB now uses readline 2.2.
3098 * set extension-language
3100 You can now control the mapping between filename extensions and source
3101 languages by using the `set extension-language' command. For instance,
3102 you can ask GDB to treat .c files as C++ by saying
3103 set extension-language .c c++
3104 The command `info extensions' lists all of the recognized extensions
3105 and their associated languages.
3107 * Setting processor type for PowerPC and RS/6000
3109 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3110 you can use the `set processor' command to specify what variant of the
3111 PowerPC family you are debugging. The command
3115 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3116 following PowerPC and RS6000 variants:
3118 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3119 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3121 403GC IBM PowerPC 403GC
3122 505 Motorola PowerPC 505
3123 860 Motorola PowerPC 860 or 850
3124 601 Motorola PowerPC 601
3125 602 Motorola PowerPC 602
3126 603 Motorola/IBM PowerPC 603 or 603e
3127 604 Motorola PowerPC 604 or 604e
3128 750 Motorola/IBM PowerPC 750 or 750
3130 At the moment, this command just tells GDB what to name the
3131 special-purpose processor registers. Since almost all the affected
3132 registers are inaccessible to user-level programs, this command is
3133 only useful for remote debugging in its present form.
3137 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3138 more extensive support for HP-UX. Added features include shared
3139 library support, kernel threads and hardware watchpoints for 11.00,
3140 support for HP's ANSI C and C++ compilers, and a compatibility mode
3141 for xdb and dbx commands.
3145 HP's donation includes the new concept of catchpoints, which is a
3146 generalization of the old catch command. On HP-UX, it is now possible
3147 to catch exec, fork, and vfork, as well as library loading.
3149 This means that the existing catch command has changed; its first
3150 argument now specifies the type of catch to be set up. See the
3151 output of "help catch" for a list of catchpoint types.
3153 * Debugging across forks
3155 On HP-UX, you can choose which process to debug when a fork() happens
3160 HP has donated a curses-based terminal user interface (TUI). To get
3161 it, build with --enable-tui. Although this can be enabled for any
3162 configuration, at present it only works for native HP debugging.
3164 * GDB remote protocol additions
3166 A new protocol packet 'X' that writes binary data is now available.
3167 Default behavior is to try 'X', then drop back to 'M' if the stub
3168 fails to respond. The settable variable `remotebinarydownload'
3169 allows explicit control over the use of 'X'.
3171 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3172 full 64-bit address. The command
3174 set remoteaddresssize 32
3176 can be used to revert to the old behaviour. For existing remote stubs
3177 the change should not be noticed, as the additional address information
3180 In order to assist in debugging stubs, you may use the maintenance
3181 command `packet' to send any text string to the stub. For instance,
3183 maint packet heythere
3185 sends the packet "$heythere#<checksum>". Note that it is very easy to
3186 disrupt a debugging session by sending the wrong packet at the wrong
3189 The compare-sections command allows you to compare section data on the
3190 target to what is in the executable file without uploading or
3191 downloading, by comparing CRC checksums.
3193 * Tracing can collect general expressions
3195 You may now collect general expressions at tracepoints. This requires
3196 further additions to the target-side stub; see tracepoint.c and
3197 doc/agentexpr.texi for further details.
3199 * mask-address variable for Mips
3201 For Mips targets, you may control the zeroing of the upper 32 bits of
3202 a 64-bit address by entering `set mask-address on'. This is mainly
3203 of interest to users of embedded R4xxx and R5xxx processors.
3205 * Higher serial baud rates
3207 GDB's serial code now allows you to specify baud rates 57600, 115200,
3208 230400, and 460800 baud. (Note that your host system may not be able
3209 to achieve all of these rates.)
3213 The i960 configuration now includes an initial implementation of a
3214 builtin simulator, contributed by Jim Wilson.
3217 *** Changes in GDB-4.17:
3219 * New native configurations
3221 Alpha GNU/Linux alpha*-*-linux*
3222 Unixware 2.x i[3456]86-unixware2*
3223 Irix 6.x mips*-sgi-irix6*
3224 PowerPC GNU/Linux powerpc-*-linux*
3225 PowerPC Solaris powerpcle-*-solaris*
3226 Sparc GNU/Linux sparc-*-linux*
3227 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3231 Argonaut Risc Chip (ARC) arc-*-*
3232 Hitachi H8/300S h8300*-*-*
3233 Matsushita MN10200 w/simulator mn10200-*-*
3234 Matsushita MN10300 w/simulator mn10300-*-*
3235 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3236 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3237 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3238 Mitsubishi D10V w/simulator d10v-*-*
3239 Mitsubishi M32R/D w/simulator m32r-*-elf*
3240 Tsqware Sparclet sparclet-*-*
3241 NEC V850 w/simulator v850-*-*
3243 * New debugging protocols
3245 ARM with RDI protocol arm*-*-*
3246 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3247 DDB and LSI variants of PMON protocol mips*-*-*
3248 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3249 PowerPC with SDS protocol powerpc{,le}-*-eabi
3250 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3254 All configurations can now understand and use the DWARF 2 debugging
3255 format. The choice is automatic, if the symbol file contains DWARF 2
3260 GDB now includes basic Java language support. This support is
3261 only useful with Java compilers that produce native machine code.
3263 * solib-absolute-prefix and solib-search-path
3265 For SunOS and SVR4 shared libraries, you may now set the prefix for
3266 loading absolute shared library symbol files, and the search path for
3267 locating non-absolute shared library symbol files.
3269 * Live range splitting
3271 GDB can now effectively debug code for which GCC has performed live
3272 range splitting as part of its optimization. See gdb/doc/LRS for
3273 more details on the expected format of the stabs information.
3277 GDB's support for the GNU Hurd, including thread debugging, has been
3278 updated to work with current versions of the Hurd.
3282 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3283 instruction set. ARM GDB automatically detects when Thumb
3284 instructions are in use, and adjusts disassembly and backtracing
3289 GDB's MIPS target configurations now handle the MIP16 16-bit
3294 GDB now includes support for overlays; if an executable has been
3295 linked such that multiple sections are based at the same address, GDB
3296 will decide which section to use for symbolic info. You can choose to
3297 control the decision manually, using overlay commands, or implement
3298 additional target-side support and use "overlay load-target" to bring
3299 in the overlay mapping. Do "help overlay" for more detail.
3303 The command "info symbol <address>" displays information about
3304 the symbol at the specified address.
3308 The standard remote protocol now includes an extension that allows
3309 asynchronous collection and display of trace data. This requires
3310 extensive support in the target-side debugging stub. Tracing mode
3311 includes a new interaction mode in GDB and new commands: see the
3312 file tracepoint.c for more details.
3316 Configurations for embedded MIPS now include a simulator contributed
3317 by Cygnus Solutions. The simulator supports the instruction sets
3318 of most MIPS variants.
3322 Sparc configurations may now include the ERC32 simulator contributed
3323 by the European Space Agency. The simulator is not built into
3324 Sparc targets by default; configure with --enable-sim to include it.
3328 For target configurations that may include multiple variants of a
3329 basic architecture (such as MIPS and SH), you may now set the
3330 architecture explicitly. "set arch" sets, "info arch" lists
3331 the possible architectures.
3333 *** Changes in GDB-4.16:
3335 * New native configurations
3337 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3338 M68K NetBSD m68k-*-netbsd*
3339 PowerPC AIX 4.x powerpc-*-aix*
3340 PowerPC MacOS powerpc-*-macos*
3341 PowerPC Windows NT powerpcle-*-cygwin32
3342 RS/6000 AIX 4.x rs6000-*-aix4*
3346 ARM with RDP protocol arm-*-*
3347 I960 with MON960 i960-*-coff
3348 MIPS VxWorks mips*-*-vxworks*
3349 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3350 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3352 Matra Sparclet sparclet-*-*
3356 The powerpc-eabi configuration now includes the PSIM simulator,
3357 contributed by Andrew Cagney, with assistance from Mike Meissner.
3358 PSIM is a very elaborate model of the PowerPC, including not only
3359 basic instruction set execution, but also details of execution unit
3360 performance and I/O hardware. See sim/ppc/README for more details.
3364 GDB now works with Solaris 2.5.
3366 * Windows 95/NT native
3368 GDB will now work as a native debugger on Windows 95 and Windows NT.
3369 To build it from source, you must use the "gnu-win32" environment,
3370 which uses a DLL to emulate enough of Unix to run the GNU tools.
3371 Further information, binaries, and sources are available at
3372 ftp.cygnus.com, under pub/gnu-win32.
3374 * dont-repeat command
3376 If a user-defined command includes the command `dont-repeat', then the
3377 command will not be repeated if the user just types return. This is
3378 useful if the command is time-consuming to run, so that accidental
3379 extra keystrokes don't run the same command many times.
3381 * Send break instead of ^C
3383 The standard remote protocol now includes an option to send a break
3384 rather than a ^C to the target in order to interrupt it. By default,
3385 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3387 * Remote protocol timeout
3389 The standard remote protocol includes a new variable `remotetimeout'
3390 that allows you to set the number of seconds before GDB gives up trying
3391 to read from the target. The default value is 2.
3393 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3395 By default GDB will automatically keep track of objects as they are
3396 loaded and unloaded by the dynamic linker. By using the command `set
3397 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3398 when shared library events occur, thus allowing you to set breakpoints
3399 in shared libraries which are explicitly loaded by the inferior.
3401 Note this feature does not work on hpux8. On hpux9 you must link
3402 /usr/lib/end.o into your program. This feature should work
3403 automatically on hpux10.
3405 * Irix 5.x hardware watchpoint support
3407 Irix 5 configurations now support the use of hardware watchpoints.
3409 * Mips protocol "SYN garbage limit"
3411 When debugging a Mips target using the `target mips' protocol, you
3412 may set the number of characters that GDB will ignore by setting
3413 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3414 every character. The default value is 1050.
3416 * Recording and replaying remote debug sessions
3418 If you set `remotelogfile' to the name of a file, gdb will write to it
3419 a recording of a remote debug session. This recording may then be
3420 replayed back to gdb using "gdbreplay". See gdbserver/README for
3421 details. This is useful when you have a problem with GDB while doing
3422 remote debugging; you can make a recording of the session and send it
3423 to someone else, who can then recreate the problem.
3425 * Speedups for remote debugging
3427 GDB includes speedups for downloading and stepping MIPS systems using
3428 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3429 and more efficient S-record downloading.
3431 * Memory use reductions and statistics collection
3433 GDB now uses less memory and reports statistics about memory usage.
3434 Try the `maint print statistics' command, for example.
3436 *** Changes in GDB-4.15:
3438 * Psymtabs for XCOFF
3440 The symbol reader for AIX GDB now uses partial symbol tables. This
3441 can greatly improve startup time, especially for large executables.
3443 * Remote targets use caching
3445 Remote targets now use a data cache to speed up communication with the
3446 remote side. The data cache could lead to incorrect results because
3447 it doesn't know about volatile variables, thus making it impossible to
3448 debug targets which use memory mapped I/O devices. `set remotecache
3449 off' turns the the data cache off.
3451 * Remote targets may have threads
3453 The standard remote protocol now includes support for multiple threads
3454 in the target system, using new protocol commands 'H' and 'T'. See
3455 gdb/remote.c for details.
3459 If GDB is configured with `--enable-netrom', then it will include
3460 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3461 acts as though it is a bank of ROM on the target board, but you can
3462 write into it over the network. GDB's support consists only of
3463 support for fast loading into the emulated ROM; to debug, you must use
3464 another protocol, such as standard remote protocol. The usual
3465 sequence is something like
3467 target nrom <netrom-hostname>
3469 target remote <netrom-hostname>:1235
3473 GDB now includes support for the Apple Macintosh, as a host only. It
3474 may be run as either an MPW tool or as a standalone application, and
3475 it can debug through the serial port. All the usual GDB commands are
3476 available, but to the target command, you must supply "serial" as the
3477 device type instead of "/dev/ttyXX". See mpw-README in the main
3478 directory for more information on how to build. The MPW configuration
3479 scripts */mpw-config.in support only a few targets, and only the
3480 mips-idt-ecoff target has been tested.
3484 GDB configuration now uses autoconf. This is not user-visible,
3485 but does simplify configuration and building.
3489 GDB now supports hpux10.
3491 *** Changes in GDB-4.14:
3493 * New native configurations
3495 x86 FreeBSD i[345]86-*-freebsd
3496 x86 NetBSD i[345]86-*-netbsd
3497 NS32k NetBSD ns32k-*-netbsd
3498 Sparc NetBSD sparc-*-netbsd
3502 A29K VxWorks a29k-*-vxworks
3503 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3504 CPU32 EST-300 emulator m68*-*-est*
3505 PowerPC ELF powerpc-*-elf
3508 * Alpha OSF/1 support for procfs
3510 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3511 possible to attach to running processes. As the mounting of the /proc
3512 filesystem is optional on the Alpha, GDB automatically determines
3513 the availability of /proc during startup. This can lead to problems
3514 if /proc is unmounted after GDB has been started.
3516 * Arguments to user-defined commands
3518 User commands may accept up to 10 arguments separated by whitespace.
3519 Arguments are accessed within the user command via $arg0..$arg9. A
3522 print $arg0 + $arg1 + $arg2
3524 To execute the command use:
3527 Defines the command "adder" which prints the sum of its three arguments.
3528 Note the arguments are text substitutions, so they may reference variables,
3529 use complex expressions, or even perform inferior function calls.
3531 * New `if' and `while' commands
3533 This makes it possible to write more sophisticated user-defined
3534 commands. Both commands take a single argument, which is the
3535 expression to evaluate, and must be followed by the commands to
3536 execute, one per line, if the expression is nonzero, the list being
3537 terminated by the word `end'. The `if' command list may include an
3538 `else' word, which causes the following commands to be executed only
3539 if the expression is zero.
3541 * Fortran source language mode
3543 GDB now includes partial support for Fortran 77. It will recognize
3544 Fortran programs and can evaluate a subset of Fortran expressions, but
3545 variables and functions may not be handled correctly. GDB will work
3546 with G77, but does not yet know much about symbols emitted by other
3549 * Better HPUX support
3551 Most debugging facilities now work on dynamic executables for HPPAs
3552 running hpux9 or later. You can attach to running dynamically linked
3553 processes, but by default the dynamic libraries will be read-only, so
3554 for instance you won't be able to put breakpoints in them. To change
3555 that behavior do the following before running the program:
3561 This will cause the libraries to be mapped private and read-write.
3562 To revert to the normal behavior, do this:
3568 You cannot set breakpoints or examine data in the library until after
3569 the library is loaded if the function/data symbols do not have
3572 GDB can now also read debug symbols produced by the HP C compiler on
3573 HPPAs (sorry, no C++, Fortran or 68k support).
3575 * Target byte order now dynamically selectable
3577 You can choose which byte order to use with a target system, via the
3578 commands "set endian big" and "set endian little", and you can see the
3579 current setting by using "show endian". You can also give the command
3580 "set endian auto", in which case GDB will use the byte order
3581 associated with the executable. Currently, only embedded MIPS
3582 configurations support dynamic selection of target byte order.
3584 * New DOS host serial code
3586 This version uses DPMI interrupts to handle buffered I/O, so you
3587 no longer need to run asynctsr when debugging boards connected to
3590 *** Changes in GDB-4.13:
3592 * New "complete" command
3594 This lists all the possible completions for the rest of the line, if it
3595 were to be given as a command itself. This is intended for use by emacs.
3597 * Trailing space optional in prompt
3599 "set prompt" no longer adds a space for you after the prompt you set. This
3600 allows you to set a prompt which ends in a space or one that does not.
3602 * Breakpoint hit counts
3604 "info break" now displays a count of the number of times the breakpoint
3605 has been hit. This is especially useful in conjunction with "ignore"; you
3606 can ignore a large number of breakpoint hits, look at the breakpoint info
3607 to see how many times the breakpoint was hit, then run again, ignoring one
3608 less than that number, and this will get you quickly to the last hit of
3611 * Ability to stop printing at NULL character
3613 "set print null-stop" will cause GDB to stop printing the characters of
3614 an array when the first NULL is encountered. This is useful when large
3615 arrays actually contain only short strings.
3617 * Shared library breakpoints
3619 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3620 breakpoints in shared libraries before the executable is run.
3622 * Hardware watchpoints
3624 There is a new hardware breakpoint for the watch command for sparclite
3625 targets. See gdb/sparclite/hw_breakpoint.note.
3627 Hardware watchpoints are also now supported under GNU/Linux.
3631 Annotations have been added. These are for use with graphical interfaces,
3632 and are still experimental. Currently only gdba.el uses these.
3634 * Improved Irix 5 support
3636 GDB now works properly with Irix 5.2.
3638 * Improved HPPA support
3640 GDB now works properly with the latest GCC and GAS.
3642 * New native configurations
3644 Sequent PTX4 i[34]86-sequent-ptx4
3645 HPPA running OSF/1 hppa*-*-osf*
3646 Atari TT running SVR4 m68*-*-sysv4*
3647 RS/6000 LynxOS rs6000-*-lynxos*
3651 OS/9000 i[34]86-*-os9k
3652 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3655 * Hitachi SH7000 and E7000-PC ICE support
3657 There is now support for communicating with the Hitachi E7000-PC ICE.
3658 This is available automatically when GDB is configured for the SH.
3662 As usual, a variety of small fixes and improvements, both generic
3663 and configuration-specific. See the ChangeLog for more detail.
3665 *** Changes in GDB-4.12:
3667 * Irix 5 is now supported
3671 GDB-4.12 on the HPPA has a number of changes which make it unable
3672 to debug the output from the currently released versions of GCC and
3673 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3674 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3675 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3678 *** Changes in GDB-4.11:
3680 * User visible changes:
3684 The "set remotedebug" option is now consistent between the mips remote
3685 target, remote targets using the gdb-specific protocol, UDI (AMD's
3686 debug protocol for the 29k) and the 88k bug monitor. It is now an
3687 integer specifying a debug level (normally 0 or 1, but 2 means more
3688 debugging info for the mips target).
3690 * DEC Alpha native support
3692 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3693 debug info, but GDB works fairly well with the DEC compiler and should
3694 work with a future GCC release. See the README file for a few
3695 Alpha-specific notes.
3697 * Preliminary thread implementation
3699 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3701 * LynxOS native and target support for 386
3703 This release has been hosted on LynxOS 2.2, and also can be configured
3704 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3707 * Improvements in C++ mangling/demangling.
3709 This release has much better g++ debugging, specifically in name
3710 mangling/demangling, virtual function calls, print virtual table,
3711 call methods, ...etc.
3713 *** Changes in GDB-4.10:
3715 * User visible changes:
3717 Remote debugging using the GDB-specific (`target remote') protocol now
3718 supports the `load' command. This is only useful if you have some
3719 other way of getting the stub to the target system, and you can put it
3720 somewhere in memory where it won't get clobbered by the download.
3722 Filename completion now works.
3724 When run under emacs mode, the "info line" command now causes the
3725 arrow to point to the line specified. Also, "info line" prints
3726 addresses in symbolic form (as well as hex).
3728 All vxworks based targets now support a user settable option, called
3729 vxworks-timeout. This option represents the number of seconds gdb
3730 should wait for responses to rpc's. You might want to use this if
3731 your vxworks target is, perhaps, a slow software simulator or happens
3732 to be on the far side of a thin network line.
3736 This release contains support for using a DEC alpha as a GDB host for
3737 cross debugging. Native alpha debugging is not supported yet.
3740 *** Changes in GDB-4.9:
3744 This is the first GDB release which is accompanied by a matching testsuite.
3745 The testsuite requires installation of dejagnu, which should be available
3746 via ftp from most sites that carry GNU software.
3750 'Cfront' style demangling has had its name changed to 'ARM' style, to
3751 emphasize that it was written from the specifications in the C++ Annotated
3752 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3753 disclaimers, it still generated too much confusion with users attempting to
3754 use gdb with AT&T cfront.
3758 GDB now uses a standard remote interface to a simulator library.
3759 So far, the library contains simulators for the Zilog Z8001/2, the
3760 Hitachi H8/300, H8/500 and Super-H.
3762 * New targets supported
3764 H8/300 simulator h8300-hitachi-hms or h8300hms
3765 H8/500 simulator h8500-hitachi-hms or h8500hms
3766 SH simulator sh-hitachi-hms or sh
3767 Z8000 simulator z8k-zilog-none or z8ksim
3768 IDT MIPS board over serial line mips-idt-ecoff
3770 Cross-debugging to GO32 targets is supported. It requires a custom
3771 version of the i386-stub.c module which is integrated with the
3772 GO32 memory extender.
3774 * New remote protocols
3776 MIPS remote debugging protocol.
3778 * New source languages supported
3780 This version includes preliminary support for Chill, a Pascal like language
3781 used by telecommunications companies. Chill support is also being integrated
3782 into the GNU compiler, but we don't know when it will be publically available.
3785 *** Changes in GDB-4.8:
3787 * HP Precision Architecture supported
3789 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3790 version of this support was available as a set of patches from the
3791 University of Utah. GDB does not support debugging of programs
3792 compiled with the HP compiler, because HP will not document their file
3793 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3794 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3796 Many problems in the preliminary version have been fixed.
3798 * Faster and better demangling
3800 We have improved template demangling and fixed numerous bugs in the GNU style
3801 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3802 character types (wchar_t) are now supported. Demangling of each symbol is now
3803 only done once, and is cached when the symbol table for a file is read in.
3804 This results in a small increase in memory usage for C programs, a moderate
3805 increase in memory usage for C++ programs, and a fantastic speedup in
3808 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3809 from the specifications in the Annotated Reference Manual, which AT&T's
3810 compiler does not actually implement.
3812 * G++ multiple inheritance compiler problem
3814 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3815 inheritance lattices was reworked to properly discover ambiguities. We
3816 recently found an example which causes this new algorithm to fail in a
3817 very subtle way, producing bad debug information for those classes.
3818 The file 'gcc.patch' (in this directory) can be applied to gcc to
3819 circumvent the problem. A future GCC release will contain a complete
3822 The previous G++ debug info problem (mentioned below for the gdb-4.7
3823 release) is fixed in gcc version 2.3.2.
3825 * Improved configure script
3827 The `configure' script will now attempt to guess your system type if
3828 you don't supply a host system type. The old scheme of supplying a
3829 host system triplet is preferable over using this. All the magic is
3830 done in the new `config.guess' script. Examine it for details.
3832 We have also brought our configure script much more in line with the FSF's
3833 version. It now supports the --with-xxx options. In particular,
3834 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
3835 The resulting GDB will not be able to read arbitrary object file formats --
3836 only the format ``expected'' to be used on the configured target system.
3837 We hope to make this the default in a future release.
3839 * Documentation improvements
3841 There's new internal documentation on how to modify GDB, and how to
3842 produce clean changes to the code. We implore people to read it
3843 before submitting changes.
3845 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
3846 M4 macros. The new texinfo.tex is provided in this release. Pre-built
3847 `info' files are also provided. To build `info' files from scratch,
3848 you will need the latest `makeinfo' release, which will be available in
3849 a future texinfo-X.Y release.
3851 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
3852 We're not sure exactly which versions have this problem, but it has
3853 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
3854 or better. If that isn't possible, there is a patch in
3855 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
3856 around this problem.
3860 GDB now supports array constants that can be used in expressions typed in by
3861 the user. The syntax is `{element, element, ...}'. Ie: you can now type
3862 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
3865 The new directory `gdb/sparclite' contains a program that demonstrates
3866 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
3868 * New native hosts supported
3870 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
3871 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
3873 * New targets supported
3875 AMD 29k family via UDI a29k-amd-udi or udi29k
3877 * New file formats supported
3879 BFD now supports reading HP/PA-RISC executables (SOM file format?),
3880 HPUX core files, and SCO 3.2v2 core files.
3884 Attaching to processes now works again; thanks for the many bug reports.
3886 We have also stomped on a bunch of core dumps caused by
3887 printf_filtered("%s") problems.
3889 We eliminated a copyright problem on the rpc and ptrace header files
3890 for VxWorks, which was discovered at the last minute during the 4.7
3891 release. You should now be able to build a VxWorks GDB.
3893 You can now interrupt gdb while an attached process is running. This
3894 will cause the attached process to stop, and give control back to GDB.
3896 We fixed problems caused by using too many file descriptors
3897 for reading symbols from object files and libraries. This was
3898 especially a problem for programs that used many (~100) shared
3901 The `step' command now only enters a subroutine if there is line number
3902 information for the subroutine. Otherwise it acts like the `next'
3903 command. Previously, `step' would enter subroutines if there was
3904 any debugging information about the routine. This avoids problems
3905 when using `cc -g1' on MIPS machines.
3907 * Internal improvements
3909 GDB's internal interfaces have been improved to make it easier to support
3910 debugging of multiple languages in the future.
3912 GDB now uses a common structure for symbol information internally.
3913 Minimal symbols (derived from linkage symbols in object files), partial
3914 symbols (from a quick scan of debug information), and full symbols
3915 contain a common subset of information, making it easier to write
3916 shared code that handles any of them.
3918 * New command line options
3920 We now accept --silent as an alias for --quiet.
3924 The memory-mapped-malloc library is now licensed under the GNU Library
3925 General Public License.
3927 *** Changes in GDB-4.7:
3929 * Host/native/target split
3931 GDB has had some major internal surgery to untangle the support for
3932 hosts and remote targets. Now, when you configure GDB for a remote
3933 target, it will no longer load in all of the support for debugging
3934 local programs on the host. When fully completed and tested, this will
3935 ensure that arbitrary host/target combinations are possible.
3937 The primary conceptual shift is to separate the non-portable code in
3938 GDB into three categories. Host specific code is required any time GDB
3939 is compiled on that host, regardless of the target. Target specific
3940 code relates to the peculiarities of the target, but can be compiled on
3941 any host. Native specific code is everything else: it can only be
3942 built when the host and target are the same system. Child process
3943 handling and core file support are two common `native' examples.
3945 GDB's use of /proc for controlling Unix child processes is now cleaner.
3946 It has been split out into a single module under the `target_ops' vector,
3947 plus two native-dependent functions for each system that uses /proc.
3949 * New hosts supported
3951 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
3952 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3953 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
3955 * New targets supported
3957 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3958 68030 and CPU32 m68030-*-*, m68332-*-*
3960 * New native hosts supported
3962 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
3963 (386bsd is not well tested yet)
3964 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
3966 * New file formats supported
3968 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
3969 supports reading of `a.out.adobe' object files, which are an a.out
3970 format extended with minimal information about multiple sections.
3974 `show copying' is the same as the old `info copying'.
3975 `show warranty' is the same as `info warrantee'.
3976 These were renamed for consistency. The old commands continue to work.
3978 `info handle' is a new alias for `info signals'.
3980 You can now define pre-command hooks, which attach arbitrary command
3981 scripts to any command. The commands in the hook will be executed
3982 prior to the user's command. You can also create a hook which will be
3983 executed whenever the program stops. See gdb.texinfo.
3987 We now deal with Cfront style name mangling, and can even extract type
3988 info from mangled symbols. GDB can automatically figure out which
3989 symbol mangling style your C++ compiler uses.
3991 Calling of methods and virtual functions has been improved as well.
3995 The crash that occured when debugging Sun Ansi-C compiled binaries is
3996 fixed. This was due to mishandling of the extra N_SO stabs output
3999 We also finally got Ultrix 4.2 running in house, and fixed core file
4000 support, with help from a dozen people on the net.
4002 John M. Farrell discovered that the reason that single-stepping was so
4003 slow on all of the Mips based platforms (primarily SGI and DEC) was
4004 that we were trying to demangle and lookup a symbol used for internal
4005 purposes on every instruction that was being stepped through. Changing
4006 the name of that symbol so that it couldn't be mistaken for a C++
4007 mangled symbol sped things up a great deal.
4009 Rich Pixley sped up symbol lookups in general by getting much smarter
4010 about when C++ symbol mangling is necessary. This should make symbol
4011 completion (TAB on the command line) much faster. It's not as fast as
4012 we'd like, but it's significantly faster than gdb-4.6.
4016 A new user controllable variable 'call_scratch_address' can
4017 specify the location of a scratch area to be used when GDB
4018 calls a function in the target. This is necessary because the
4019 usual method of putting the scratch area on the stack does not work
4020 in systems that have separate instruction and data spaces.
4022 We integrated changes to support the 29k UDI (Universal Debugger
4023 Interface), but discovered at the last minute that we didn't have all
4024 of the appropriate copyright paperwork. We are working with AMD to
4025 resolve this, and hope to have it available soon.
4029 We have sped up the remote serial line protocol, especially for targets
4030 with lots of registers. It now supports a new `expedited status' ('T')
4031 message which can be used in place of the existing 'S' status message.
4032 This allows the remote stub to send only the registers that GDB
4033 needs to make a quick decision about single-stepping or conditional
4034 breakpoints, eliminating the need to fetch the entire register set for
4035 each instruction being stepped through.
4037 The GDB remote serial protocol now implements a write-through cache for
4038 registers, only re-reading the registers if the target has run.
4040 There is also a new remote serial stub for SPARC processors. You can
4041 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4042 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4043 processor with a serial port.
4047 Configure.in files have become much easier to read and modify. A new
4048 `table driven' format makes it more obvious what configurations are
4049 supported, and what files each one uses.
4053 There is a new opcodes library which will eventually contain all of the
4054 disassembly routines and opcode tables. At present, it only contains
4055 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4056 disassembler (binutils/objdump) to share these routines.
4058 The libiberty library is now copylefted under the GNU Library General
4059 Public License. This allows more liberal use, and was done so libg++
4060 can use it. This makes no difference to GDB, since the Library License
4061 grants all the rights from the General Public License.
4065 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4066 reference to the stabs symbol info used by the debugger. It is (as far
4067 as we know) the only published document on this fascinating topic. We
4068 encourage you to read it, compare it to the stabs information on your
4069 system, and send improvements on the document in general (to
4070 bug-gdb@prep.ai.mit.edu).
4072 And, of course, many bugs have been fixed.
4075 *** Changes in GDB-4.6:
4077 * Better support for C++ function names
4079 GDB now accepts as input the "demangled form" of C++ overloaded function
4080 names and member function names, and can do command completion on such names
4081 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4082 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4083 Make use of command completion, it is your friend.
4085 GDB also now accepts a variety of C++ mangled symbol formats. They are
4086 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4087 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4088 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4089 for the list of formats.
4091 * G++ symbol mangling problem
4093 Recent versions of gcc have a bug in how they emit debugging information for
4094 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4095 directory) can be applied to gcc to fix the problem. Alternatively, if you
4096 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4097 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4098 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4101 * New 'maintenance' command
4103 All of the commands related to hacking GDB internals have been moved out of
4104 the main command set, and now live behind the 'maintenance' command. This
4105 can also be abbreviated as 'mt'. The following changes were made:
4107 dump-me -> maintenance dump-me
4108 info all-breakpoints -> maintenance info breakpoints
4109 printmsyms -> maintenance print msyms
4110 printobjfiles -> maintenance print objfiles
4111 printpsyms -> maintenance print psymbols
4112 printsyms -> maintenance print symbols
4114 The following commands are new:
4116 maintenance demangle Call internal GDB demangler routine to
4117 demangle a C++ link name and prints the result.
4118 maintenance print type Print a type chain for a given symbol
4120 * Change to .gdbinit file processing
4122 We now read the $HOME/.gdbinit file before processing the argv arguments
4123 (e.g. reading symbol files or core files). This allows global parameters to
4124 be set, which will apply during the symbol reading. The ./.gdbinit is still
4125 read after argv processing.
4127 * New hosts supported
4129 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4131 GNU/Linux support i386-unknown-linux or linux
4133 We are also including code to support the HP/PA running BSD and HPUX. This
4134 is almost guaranteed not to work, as we didn't have time to test or build it
4135 for this release. We are including it so that the more adventurous (or
4136 masochistic) of you can play with it. We also had major problems with the
4137 fact that the compiler that we got from HP doesn't support the -g option.
4140 * New targets supported
4142 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4144 * More smarts about finding #include files
4146 GDB now remembers the compilation directory for all include files, and for
4147 all files from which C is generated (like yacc and lex sources). This
4148 greatly improves GDB's ability to find yacc/lex sources, and include files,
4149 especially if you are debugging your program from a directory different from
4150 the one that contains your sources.
4152 We also fixed a bug which caused difficulty with listing and setting
4153 breakpoints in include files which contain C code. (In the past, you had to
4154 try twice in order to list an include file that you hadn't looked at before.)
4156 * Interesting infernals change
4158 GDB now deals with arbitrary numbers of sections, where the symbols for each
4159 section must be relocated relative to that section's landing place in the
4160 target's address space. This work was needed to support ELF with embedded
4161 stabs used by Solaris-2.0.
4163 * Bug fixes (of course!)
4165 There have been loads of fixes for the following things:
4166 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4167 i960, stabs, DOS(GO32), procfs, etc...
4169 See the ChangeLog for details.
4171 *** Changes in GDB-4.5:
4173 * New machines supported (host and target)
4175 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4177 SGI Irix-4.x mips-sgi-irix4 or iris4
4179 * New malloc package
4181 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4182 Mmalloc is capable of handling mutiple heaps of memory. It is also
4183 capable of saving a heap to a file, and then mapping it back in later.
4184 This can be used to greatly speedup the startup of GDB by using a
4185 pre-parsed symbol table which lives in a mmalloc managed heap. For
4186 more details, please read mmalloc/mmalloc.texi.
4190 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4191 'help info proc' for details.
4193 * MIPS ecoff symbol table format
4195 The code that reads MIPS symbol table format is now supported on all hosts.
4196 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4199 * File name changes for MS-DOS
4201 Many files in the config directories have been renamed to make it easier to
4202 support GDB on MS-DOSe systems (which have very restrictive file name
4203 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4204 environment) is close to working but has some remaining problems. Note
4205 that debugging of DOS programs is not supported, due to limitations
4206 in the ``operating system'', but it can be used to host cross-debugging.
4208 * Cross byte order fixes
4210 Many fixes have been made to support cross debugging of Sparc and MIPS
4211 targets from hosts whose byte order differs.
4213 * New -mapped and -readnow options
4215 If memory-mapped files are available on your system through the 'mmap'
4216 system call, you can use the -mapped option on the `file' or
4217 `symbol-file' commands to cause GDB to write the symbols from your
4218 program into a reusable file. If the program you are debugging is
4219 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4220 Future GDB debugging sessions will notice the presence of this file,
4221 and will quickly map in symbol information from it, rather than reading
4222 the symbol table from the executable program. Using the '-mapped'
4223 option in a GDB `file' or `symbol-file' command has the same effect as
4224 starting GDB with the '-mapped' command-line option.
4226 You can cause GDB to read the entire symbol table immediately by using
4227 the '-readnow' option with any of the commands that load symbol table
4228 information (or on the GDB command line). This makes the command
4229 slower, but makes future operations faster.
4231 The -mapped and -readnow options are typically combined in order to
4232 build a `fred.syms' file that contains complete symbol information.
4233 A simple GDB invocation to do nothing but build a `.syms' file for future
4236 gdb -batch -nx -mapped -readnow programname
4238 The `.syms' file is specific to the host machine on which GDB is run.
4239 It holds an exact image of GDB's internal symbol table. It cannot be
4240 shared across multiple host platforms.
4242 * longjmp() handling
4244 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4245 siglongjmp() without losing control. This feature has not yet been ported to
4246 all systems. It currently works on many 386 platforms, all MIPS-based
4247 platforms (SGI, DECstation, etc), and Sun3/4.
4251 Preliminary work has been put in to support the new Solaris OS from Sun. At
4252 this time, it can control and debug processes, but it is not capable of
4257 As always, many many bug fixes. The major areas were with g++, and mipsread.
4258 People using the MIPS-based platforms should experience fewer mysterious
4259 crashes and trashed symbol tables.
4261 *** Changes in GDB-4.4:
4263 * New machines supported (host and target)
4265 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4267 BSD Reno on Vax vax-dec-bsd
4268 Ultrix on Vax vax-dec-ultrix
4270 * New machines supported (target)
4272 AMD 29000 embedded, using EBMON a29k-none-none
4276 GDB continues to improve its handling of C++. `References' work better.
4277 The demangler has also been improved, and now deals with symbols mangled as
4278 per the Annotated C++ Reference Guide.
4280 GDB also now handles `stabs' symbol information embedded in MIPS
4281 `ecoff' symbol tables. Since the ecoff format was not easily
4282 extensible to handle new languages such as C++, this appeared to be a
4283 good way to put C++ debugging info into MIPS binaries. This option
4284 will be supported in the GNU C compiler, version 2, when it is
4287 * New features for SVR4
4289 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4290 shared libraries. Debugging dynamically linked programs should present
4291 only minor differences from debugging statically linked programs.
4293 The `info proc' command will print out information about any process
4294 on an SVR4 system (including the one you are debugging). At the moment,
4295 it prints the address mappings of the process.
4297 If you bring up GDB on another SVR4 system, please send mail to
4298 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4300 * Better dynamic linking support in SunOS
4302 Reading symbols from shared libraries which contain debugging symbols
4303 now works properly. However, there remain issues such as automatic
4304 skipping of `transfer vector' code during function calls, which
4305 make it harder to debug code in a shared library, than to debug the
4306 same code linked statically.
4310 GDB is now using the latest `getopt' routines from the FSF. This
4311 version accepts the -- prefix for options with long names. GDB will
4312 continue to accept the old forms (-option and +option) as well.
4313 Various single letter abbreviations for options have been explicity
4314 added to the option table so that they won't get overshadowed in the
4315 future by other options that begin with the same letter.
4319 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4320 Many assorted bugs have been handled. Many more remain to be handled.
4321 See the various ChangeLog files (primarily in gdb and bfd) for details.
4324 *** Changes in GDB-4.3:
4326 * New machines supported (host and target)
4328 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4329 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4330 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4332 * Almost SCO Unix support
4334 We had hoped to support:
4335 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4336 (except for core file support), but we discovered very late in the release
4337 that it has problems with process groups that render gdb unusable. Sorry
4338 about that. I encourage people to fix it and post the fixes.
4340 * Preliminary ELF and DWARF support
4342 GDB can read ELF object files on System V Release 4, and can handle
4343 debugging records for C, in DWARF format, in ELF files. This support
4344 is preliminary. If you bring up GDB on another SVR4 system, please
4345 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4350 GDB now uses the latest `readline' library. One user-visible change
4351 is that two tabs will list possible command completions, which previously
4352 required typing M-? (meta-question mark, or ESC ?).
4356 The `stepi' bug that many of you noticed has been squashed.
4357 Many bugs in C++ have been handled. Many more remain to be handled.
4358 See the various ChangeLog files (primarily in gdb and bfd) for details.
4360 * State of the MIPS world (in case you wondered):
4362 GDB can understand the symbol tables emitted by the compilers
4363 supplied by most vendors of MIPS-based machines, including DEC. These
4364 symbol tables are in a format that essentially nobody else uses.
4366 Some versions of gcc come with an assembler post-processor called
4367 mips-tfile. This program is required if you want to do source-level
4368 debugging of gcc-compiled programs. I believe FSF does not ship
4369 mips-tfile with gcc version 1, but it will eventually come with gcc
4372 Debugging of g++ output remains a problem. g++ version 1.xx does not
4373 really support it at all. (If you're lucky, you should be able to get
4374 line numbers and stack traces to work, but no parameters or local
4375 variables.) With some work it should be possible to improve the
4378 When gcc version 2 is released, you will have somewhat better luck.
4379 However, even then you will get confusing results for inheritance and
4382 We will eventually provide full debugging of g++ output on
4383 DECstations. This will probably involve some kind of stabs-in-ecoff
4384 encapulation, but the details have not been worked out yet.
4387 *** Changes in GDB-4.2:
4389 * Improved configuration
4391 Only one copy of `configure' exists now, and it is not self-modifying.
4392 Porting BFD is simpler.
4396 The `step' and `next' commands now only stop at the first instruction
4397 of a source line. This prevents the multiple stops that used to occur
4398 in switch statements, for-loops, etc. `Step' continues to stop if a
4399 function that has debugging information is called within the line.
4403 Lots of small bugs fixed. More remain.
4405 * New host supported (not target)
4407 Intel 386 PC clone running Mach i386-none-mach
4410 *** Changes in GDB-4.1:
4412 * Multiple source language support
4414 GDB now has internal scaffolding to handle several source languages.
4415 It determines the type of each source file from its filename extension,
4416 and will switch expression parsing and number formatting to match the
4417 language of the function in the currently selected stack frame.
4418 You can also specifically set the language to be used, with
4419 `set language c' or `set language modula-2'.
4423 GDB now has preliminary support for the GNU Modula-2 compiler,
4424 currently under development at the State University of New York at
4425 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4426 continue through the fall of 1991 and into 1992.
4428 Other Modula-2 compilers are currently not supported, and attempting to
4429 debug programs compiled with them will likely result in an error as the
4430 symbol table is read. Feel free to work on it, though!
4432 There are hooks in GDB for strict type checking and range checking,
4433 in the `Modula-2 philosophy', but they do not currently work.
4437 GDB can now write to executable and core files (e.g. patch
4438 a variable's value). You must turn this switch on, specify
4439 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4440 by assigning a new value to a variable. Modifications take
4443 * Automatic SunOS shared library reading
4445 When you run your program, GDB automatically determines where its
4446 shared libraries (if any) have been loaded, and reads their symbols.
4447 The `share' command is no longer needed. This also works when
4448 examining core files.
4452 You can specify the number of lines that the `list' command shows.
4455 * New machines supported (host and target)
4457 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4458 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4459 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4461 * New hosts supported (not targets)
4463 IBM RT/PC: romp-ibm-aix or rtpc
4465 * New targets supported (not hosts)
4467 AMD 29000 embedded with COFF a29k-none-coff
4468 AMD 29000 embedded with a.out a29k-none-aout
4469 Ultracomputer remote kernel debug a29k-nyu-kern
4471 * New remote interfaces
4477 *** Changes in GDB-4.0:
4481 Wide output is wrapped at good places to make the output more readable.
4483 Gdb now supports cross-debugging from a host machine of one type to a
4484 target machine of another type. Communication with the target system
4485 is over serial lines. The ``target'' command handles connecting to the
4486 remote system; the ``load'' command will download a program into the
4487 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4488 also supports debugging of realtime processes running under VxWorks,
4489 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4490 stub on the target system.
4492 New CPUs supported include the AMD 29000 and Intel 960.
4494 GDB now reads object files and symbol tables via a ``binary file''
4495 library, which allows a single copy of GDB to debug programs of multiple
4496 object file types such as a.out and coff.
4498 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4499 refcard.dvi and refcard.ps are available to format it).
4502 * Control-Variable user interface simplified
4504 All variables that control the operation of the debugger can be set
4505 by the ``set'' command, and displayed by the ``show'' command.
4507 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4508 ``Show prompt'' produces the response:
4509 Gdb's prompt is new-gdb=>.
4511 What follows are the NEW set commands. The command ``help set'' will
4512 print a complete list of old and new set commands. ``help set FOO''
4513 will give a longer description of the variable FOO. ``show'' will show
4514 all of the variable descriptions and their current settings.
4516 confirm on/off: Enables warning questions for operations that are
4517 hard to recover from, e.g. rerunning the program while
4518 it is already running. Default is ON.
4520 editing on/off: Enables EMACS style command line editing
4521 of input. Previous lines can be recalled with
4522 control-P, the current line can be edited with control-B,
4523 you can search for commands with control-R, etc.
4526 history filename NAME: NAME is where the gdb command history
4527 will be stored. The default is .gdb_history,
4528 or the value of the environment variable
4531 history size N: The size, in commands, of the command history. The
4532 default is 256, or the value of the environment variable
4535 history save on/off: If this value is set to ON, the history file will
4536 be saved after exiting gdb. If set to OFF, the
4537 file will not be saved. The default is OFF.
4539 history expansion on/off: If this value is set to ON, then csh-like
4540 history expansion will be performed on
4541 command line input. The default is OFF.
4543 radix N: Sets the default radix for input and output. It can be set
4544 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4545 in the current radix, so "set radix 10" is always a no-op.
4547 height N: This integer value is the number of lines on a page. Default
4548 is 24, the current `stty rows'' setting, or the ``li#''
4549 setting from the termcap entry matching the environment
4552 width N: This integer value is the number of characters on a line.
4553 Default is 80, the current `stty cols'' setting, or the ``co#''
4554 setting from the termcap entry matching the environment
4557 Note: ``set screensize'' is obsolete. Use ``set height'' and
4558 ``set width'' instead.
4560 print address on/off: Print memory addresses in various command displays,
4561 such as stack traces and structure values. Gdb looks
4562 more ``symbolic'' if you turn this off; it looks more
4563 ``machine level'' with it on. Default is ON.
4565 print array on/off: Prettyprint arrays. New convenient format! Default
4568 print demangle on/off: Print C++ symbols in "source" form if on,
4571 print asm-demangle on/off: Same, for assembler level printouts
4574 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4577 * Support for Epoch Environment.
4579 The epoch environment is a version of Emacs v18 with windowing. One
4580 new command, ``inspect'', is identical to ``print'', except that if you
4581 are running in the epoch environment, the value is printed in its own
4585 * Support for Shared Libraries
4587 GDB can now debug programs and core files that use SunOS shared libraries.
4588 Symbols from a shared library cannot be referenced
4589 before the shared library has been linked with the program (this
4590 happens after you type ``run'' and before the function main() is entered).
4591 At any time after this linking (including when examining core files
4592 from dynamically linked programs), gdb reads the symbols from each
4593 shared library when you type the ``sharedlibrary'' command.
4594 It can be abbreviated ``share''.
4596 sharedlibrary REGEXP: Load shared object library symbols for files
4597 matching a unix regular expression. No argument
4598 indicates to load symbols for all shared libraries.
4600 info sharedlibrary: Status of loaded shared libraries.
4605 A watchpoint stops execution of a program whenever the value of an
4606 expression changes. Checking for this slows down execution
4607 tremendously whenever you are in the scope of the expression, but is
4608 quite useful for catching tough ``bit-spreader'' or pointer misuse
4609 problems. Some machines such as the 386 have hardware for doing this
4610 more quickly, and future versions of gdb will use this hardware.
4612 watch EXP: Set a watchpoint (breakpoint) for an expression.
4614 info watchpoints: Information about your watchpoints.
4616 delete N: Deletes watchpoint number N (same as breakpoints).
4617 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4618 enable N: Re-enables watchpoint number N (same as breakpoints).
4621 * C++ multiple inheritance
4623 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4626 * C++ exception handling
4628 Gdb now supports limited C++ exception handling. Besides the existing
4629 ability to breakpoint on an exception handler, gdb can breakpoint on
4630 the raising of an exception (before the stack is peeled back to the
4633 catch FOO: If there is a FOO exception handler in the dynamic scope,
4634 set a breakpoint to catch exceptions which may be raised there.
4635 Multiple exceptions (``catch foo bar baz'') may be caught.
4637 info catch: Lists all exceptions which may be caught in the
4638 current stack frame.
4641 * Minor command changes
4643 The command ``call func (arg, arg, ...)'' now acts like the print
4644 command, except it does not print or save a value if the function's result
4645 is void. This is similar to dbx usage.
4647 The ``up'' and ``down'' commands now always print the frame they end up
4648 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4649 frames without printing.
4651 * New directory command
4653 'dir' now adds directories to the FRONT of the source search path.
4654 The path starts off empty. Source files that contain debug information
4655 about the directory in which they were compiled can be found even
4656 with an empty path; Sun CC and GCC include this information. If GDB can't
4657 find your source file in the current directory, type "dir .".
4659 * Configuring GDB for compilation
4661 For normal use, type ``./configure host''. See README or gdb.texinfo
4664 GDB now handles cross debugging. If you are remotely debugging between
4665 two different machines, type ``./configure host -target=targ''.
4666 Host is the machine where GDB will run; targ is the machine
4667 where the program that you are debugging will run.