1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
8 ** The "maint set python print-stack on|off" is now deleted.
10 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
11 apply "flag enum"-style pretty-printing to any enum.
13 ** gdb.lookup_symbol can now work when there is no current frame.
15 ** gdb.Symbol now has a 'line' attribute, holding the line number in
16 the source at which the symbol was defined.
18 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
19 method 'value'. The former indicates whether the symbol needs a
20 frame in order to compute its value, and the latter computes the
23 * GDBserver now supports stdio connections.
24 E.g. (gdb) target remote | ssh myhost gdbserver - hello
26 * The binary "gdbtui" can no longer be built or installed.
27 Use "gdb -tui" instead.
29 * GDB will now print "flag" enums specially. A flag enum is one where
30 all the enumerator values have no bits in common when pairwise
31 "and"ed. When printing a value whose type is a flag enum, GDB will
32 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
33 (gdb) print (enum E) 3
36 * The filename part of a linespec will now match trailing components
37 of a source file name. For example, "break gcc/expr.c:1000" will
38 now set a breakpoint in build/gcc/expr.c, but not
41 * The "info proc" and "generate-core-file" commands will now also
42 work on remote targets connected to GDBserver on Linux.
44 * The command "info catch" has been removed. It has been disabled
49 ** "catch load" and "catch unload" can be used to stop when a shared
50 library is loaded or unloaded, respectively.
52 ** "enable count" can be used to auto-disable a breakpoint after
57 Renesas RL78 rl78-*-elf
59 * GDBserver supports evaluation of breakpoint conditions. When
60 support is advertised by GDBserver, GDB may be told to send the
61 breakpoint conditions in bytecode form to GDBserver. GDBserver
62 will only report the breakpoint trigger to GDB when its condition
67 set breakpoint condition-evaluation
68 show breakpoint condition-evaluation
69 Controls whether breakpoint conditions are evaluated by GDB ("gdb") or by
71 This option can improve debugger efficiency depending on the speed of the
76 The z0/z1 breakpoint insertion packets have been extended to carry
77 a list of conditional expressions over to the remote stub depending on the
78 condition evaluation mode. The use of this extension can be controlled
79 via the "set remote conditional-breakpoints-packet" command.
81 *** Changes in GDB 7.4
83 * GDB now handles ambiguous linespecs more consistently; the existing
84 FILE:LINE support has been expanded to other types of linespecs. A
85 breakpoint will now be set on all matching locations in all
86 inferiors, and locations will be added or removed according to
89 * GDB now allows you to skip uninteresting functions and files when
90 stepping with the "skip function" and "skip file" commands.
92 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
93 and "show remote hardware-watchpoint-length-limit". These allows to
94 set or show the maximum length limit (in bytes) of a remote
95 target hardware watchpoint.
97 This allows e.g. to use "unlimited" hardware watchpoints with the
98 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
99 watchpoints are slower than real hardware watchpoints but are
100 significantly faster than gdb software watchpoints.
104 ** The register_pretty_printer function in module gdb.printing now takes
105 an optional `replace' argument. If True, the new printer replaces any
108 ** The "maint set python print-stack on|off" command has been
109 deprecated and will be deleted in GDB 7.5.
110 A new command: "set python print-stack none|full|message" has
111 replaced it. Additionally, the default for "print-stack" is
112 now "message", which just prints the error message without
115 ** A prompt substitution hook (prompt_hook) is now available to the
118 ** A new Python module, gdb.prompt has been added to the GDB Python
119 modules library. This module provides functionality for
120 escape sequences in prompts (used by set/show
121 extended-prompt). These escape sequences are replaced by their
124 ** Python commands and convenience-functions located in
125 'data-directory'/python/gdb/command and
126 'data-directory'/python/gdb/function are now automatically loaded
129 ** Blocks now provide four new attributes. global_block and
130 static_block will return the global and static blocks
131 respectively. is_static and is_global are boolean attributes
132 that indicate if the block is one of those two types.
134 ** Symbols now provide the "type" attribute, the type of the symbol.
136 ** The "gdb.breakpoint" function has been deprecated in favor of
139 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
140 of a function. This class is based on the "finish" command
141 available in the CLI.
143 ** Type objects for struct and union types now allow access to
144 the fields using standard Python dictionary (mapping) methods.
145 For example, "some_type['myfield']" now works, as does
148 ** A new event "gdb.new_objfile" has been added, triggered by loading a
151 ** A new function, "deep_items" has been added to the gdb.types
152 module in the GDB Python modules library. This function returns
153 an iterator over the fields of a struct or union type. Unlike
154 the standard Python "iteritems" method, it will recursively traverse
155 any anonymous fields.
159 ** "*stopped" events can report several new "reason"s, such as
162 ** Breakpoint changes are now notified using new async records, like
163 "=breakpoint-modified".
165 ** New command -ada-task-info.
167 * libthread-db-search-path now supports two special values: $sdir and $pdir.
168 $sdir specifies the default system locations of shared libraries.
169 $pdir specifies the directory where the libpthread used by the application
172 GDB no longer looks in $sdir and $pdir after it has searched the directories
173 mentioned in libthread-db-search-path. If you want to search those
174 directories, they must be specified in libthread-db-search-path.
175 The default value of libthread-db-search-path on GNU/Linux and Solaris
176 systems is now "$sdir:$pdir".
178 $pdir is not supported by gdbserver, it is currently ignored.
179 $sdir is supported by gdbserver.
181 * New configure option --with-iconv-bin.
182 When using the internationalization support like the one in the GNU C
183 library, GDB will invoke the "iconv" program to get a list of supported
184 character sets. If this program lives in a non-standard location, one can
185 use this option to specify where to find it.
187 * When natively debugging programs on PowerPC BookE processors running
188 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
189 watchpoints, which specify a mask in addition to an address to watch.
190 The mask specifies that some bits of an address (the bits which are
191 reset in the mask) should be ignored when matching the address accessed
192 by the inferior against the watchpoint address. See the "PowerPC Embedded"
193 section in the user manual for more details.
195 * The new option --once causes GDBserver to stop listening for connections once
196 the first connection is made. The listening port used by GDBserver will
197 become available after that.
199 * New commands "info macros" and "alias" have been added.
201 * New function parameters suffix @entry specifies value of function parameter
202 at the time the function got called. Entry values are available only since
208 "!" is now an alias of the "shell" command.
209 Note that no space is needed between "!" and SHELL COMMAND.
213 watch EXPRESSION mask MASK_VALUE
214 The watch command now supports the mask argument which allows creation
215 of masked watchpoints, if the current architecture supports this feature.
217 info auto-load-scripts [REGEXP]
218 This command was formerly named "maintenance print section-scripts".
219 It is now generally useful and is no longer a maintenance-only command.
221 info macro [-all] [--] MACRO
222 The info macro command has new options `-all' and `--'. The first for
223 printing all definitions of a macro. The second for explicitly specifying
224 the end of arguments and the beginning of the macro name in case the macro
225 name starts with a hyphen.
227 collect[/s] EXPRESSIONS
228 The tracepoint collect command now takes an optional modifier "/s"
229 that directs it to dereference pointer-to-character types and
230 collect the bytes of memory up to a zero byte. The behavior is
231 similar to what you see when you use the regular print command on a
232 string. An optional integer following the "/s" sets a bound on the
233 number of bytes that will be collected.
236 The trace start command now interprets any supplied arguments as a
237 note to be recorded with the trace run, with an effect similar to
238 setting the variable trace-notes.
241 The trace stop command now interprets any arguments as a note to be
242 mentioned along with the tstatus report that the trace was stopped
243 with a command. The effect is similar to setting the variable
246 * Tracepoints can now be enabled and disabled at any time after a trace
247 experiment has been started using the standard "enable" and "disable"
248 commands. It is now possible to start a trace experiment with no enabled
249 tracepoints; GDB will display a warning, but will allow the experiment to
250 begin, assuming that tracepoints will be enabled as needed while the trace
253 * Fast tracepoints on 32-bit x86-architectures can now be placed at
254 locations with 4-byte instructions, when they were previously
255 limited to locations with instructions of 5 bytes or longer.
261 Set the GDB prompt, and allow escape sequences to be inserted to
262 display miscellaneous information (see 'help set extended-prompt'
263 for the list of sequences). This prompt (and any information
264 accessed through the escape sequences) is updated every time the
267 set print entry-values (both|compact|default|if-needed|no|only|preferred)
268 show print entry-values
269 Set printing of frame argument values at function entry. In some cases
270 GDB can determine the value of function argument which was passed by the
271 function caller, even if the value was modified inside the called function.
273 set debug entry-values
274 show debug entry-values
275 Control display of debugging info for determining frame argument values at
276 function entry and virtual tail call frames.
278 set basenames-may-differ
279 show basenames-may-differ
280 Set whether a source file may have multiple base names.
281 (A "base name" is the name of a file with the directory part removed.
282 Example: The base name of "/home/user/hello.c" is "hello.c".)
283 If set, GDB will canonicalize file names (e.g., expand symlinks)
284 before comparing them. Canonicalization is an expensive operation,
285 but it allows the same file be known by more than one base name.
286 If not set (the default), all source files are assumed to have just
287 one base name, and gdb will do file name comparisons more efficiently.
293 Set a user name and notes for the current and any future trace runs.
294 This is useful for long-running and/or disconnected traces, to
295 inform others (or yourself) as to who is running the trace, supply
296 contact information, or otherwise explain what is going on.
299 show trace-stop-notes
300 Set a note attached to the trace run, that is displayed when the
301 trace has been stopped by a tstop command. This is useful for
302 instance as an explanation, if you are stopping a trace run that was
303 started by someone else.
309 Dynamically enable a tracepoint in a started trace experiment.
313 Dynamically disable a tracepoint in a started trace experiment.
317 Set the user and notes of the trace run.
321 Query the current status of a tracepoint.
325 Query the minimum length of instruction at which a fast tracepoint may
328 * Dcache size (number of lines) and line-size are now runtime-configurable
329 via "set dcache line" and "set dcache line-size" commands.
333 Texas Instruments TMS320C6x tic6x-*-*
337 Renesas RL78 rl78-*-elf
339 *** Changes in GDB 7.3.1
341 * The build failure for NetBSD and OpenBSD targets have now been fixed.
343 *** Changes in GDB 7.3
345 * GDB has a new command: "thread find [REGEXP]".
346 It finds the thread id whose name, target id, or thread extra info
347 matches the given regular expression.
349 * The "catch syscall" command now works on mips*-linux* targets.
351 * The -data-disassemble MI command now supports modes 2 and 3 for
352 dumping the instruction opcodes.
354 * New command line options
356 -data-directory DIR Specify DIR as the "data-directory".
357 This is mostly for testing purposes.
359 * The "maint set python auto-load on|off" command has been renamed to
360 "set auto-load-scripts on|off".
362 * GDB has a new command: "set directories".
363 It is like the "dir" command except that it replaces the
364 source path list instead of augmenting it.
366 * GDB now understands thread names.
368 On GNU/Linux, "info threads" will display the thread name as set by
369 prctl or pthread_setname_np.
371 There is also a new command, "thread name", which can be used to
372 assign a name internally for GDB to display.
375 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
376 has been integrated into GDB.
380 ** The function gdb.Write now accepts an optional keyword 'stream'.
381 This keyword, when provided, will direct the output to either
382 stdout, stderr, or GDB's logging output.
384 ** Parameters can now be be sub-classed in Python, and in particular
385 you may implement the get_set_doc and get_show_doc functions.
386 This improves how Parameter set/show documentation is processed
387 and allows for more dynamic content.
389 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
390 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
391 have an is_valid method.
393 ** Breakpoints can now be sub-classed in Python, and in particular
394 you may implement a 'stop' function that is executed each time
395 the inferior reaches that breakpoint.
397 ** New function gdb.lookup_global_symbol looks up a global symbol.
399 ** GDB values in Python are now callable if the value represents a
400 function. For example, if 'some_value' represents a function that
401 takes two integer parameters and returns a value, you can call
402 that function like so:
404 result = some_value (10,20)
406 ** Module gdb.types has been added.
407 It contains a collection of utilities for working with gdb.Types objects:
408 get_basic_type, has_field, make_enum_dict.
410 ** Module gdb.printing has been added.
411 It contains utilities for writing and registering pretty-printers.
412 New classes: PrettyPrinter, SubPrettyPrinter,
413 RegexpCollectionPrettyPrinter.
414 New function: register_pretty_printer.
416 ** New commands "info pretty-printers", "enable pretty-printer" and
417 "disable pretty-printer" have been added.
419 ** gdb.parameter("directories") is now available.
421 ** New function gdb.newest_frame returns the newest frame in the
424 ** The gdb.InferiorThread class has a new "name" attribute. This
425 holds the thread's name.
427 ** Python Support for Inferior events.
428 Python scripts can add observers to be notified of events
429 occurring in the process being debugged.
430 The following events are currently supported:
431 - gdb.events.cont Continue event.
432 - gdb.events.exited Inferior exited event.
433 - gdb.events.stop Signal received, and Breakpoint hit events.
437 ** GDB now puts template parameters in scope when debugging in an
438 instantiation. For example, if you have:
440 template<int X> int func (void) { return X; }
442 then if you step into func<5>, "print X" will show "5". This
443 feature requires proper debuginfo support from the compiler; it
444 was added to GCC 4.5.
446 ** The motion commands "next", "finish", "until", and "advance" now
447 work better when exceptions are thrown. In particular, GDB will
448 no longer lose control of the inferior; instead, the GDB will
449 stop the inferior at the point at which the exception is caught.
450 This functionality requires a change in the exception handling
451 code that was introduced in GCC 4.5.
453 * GDB now follows GCC's rules on accessing volatile objects when
454 reading or writing target state during expression evaluation.
455 One notable difference to prior behavior is that "print x = 0"
456 no longer generates a read of x; the value of the assignment is
457 now always taken directly from the value being assigned.
459 * GDB now has some support for using labels in the program's source in
460 linespecs. For instance, you can use "advance label" to continue
461 execution to a label.
463 * GDB now has support for reading and writing a new .gdb_index
464 section. This section holds a fast index of DWARF debugging
465 information and can be used to greatly speed up GDB startup and
466 operation. See the documentation for `save gdb-index' for details.
468 * The "watch" command now accepts an optional "-location" argument.
469 When used, this causes GDB to watch the memory referred to by the
470 expression. Such a watchpoint is never deleted due to it going out
473 * GDB now supports thread debugging of core dumps on GNU/Linux.
475 GDB now activates thread debugging using the libthread_db library
476 when debugging GNU/Linux core dumps, similarly to when debugging
477 live processes. As a result, when debugging a core dump file, GDB
478 is now able to display pthread_t ids of threads. For example, "info
479 threads" shows the same output as when debugging the process when it
480 was live. In earlier releases, you'd see something like this:
483 * 1 LWP 6780 main () at main.c:10
485 While now you see this:
488 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
490 It is also now possible to inspect TLS variables when debugging core
493 When debugging a core dump generated on a machine other than the one
494 used to run GDB, you may need to point GDB at the correct
495 libthread_db library with the "set libthread-db-search-path"
496 command. See the user manual for more details on this command.
498 * When natively debugging programs on PowerPC BookE processors running
499 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
500 which stop execution of the inferior whenever it executes an instruction
501 at any address within the specified range. See the "PowerPC Embedded"
502 section in the user manual for more details.
504 * New features in the GDB remote stub, GDBserver
506 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
507 and i686 LynxOS (version 5.x).
509 ** GDBserver is now supported on Blackfin Linux.
511 * New native configurations
513 ia64 HP-UX ia64-*-hpux*
517 Analog Devices, Inc. Blackfin Processor bfin-*
519 * Ada task switching is now supported on sparc-elf targets when
520 debugging a program using the Ravenscar Profile. For more information,
521 see the "Tasking Support when using the Ravenscar Profile" section
522 in the GDB user manual.
524 * Guile support was removed.
526 * New features in the GNU simulator
528 ** The --map-info flag lists all known core mappings.
530 ** CFI flashes may be simulated via the "cfi" device.
532 *** Changes in GDB 7.2
534 * Shared library support for remote targets by default
536 When GDB is configured for a generic, non-OS specific target, like
537 for example, --target=arm-eabi or one of the many *-*-elf targets,
538 GDB now queries remote stubs for loaded shared libraries using the
539 `qXfer:libraries:read' packet. Previously, shared library support
540 was always disabled for such configurations.
544 ** Argument Dependent Lookup (ADL)
546 In C++ ADL lookup directs function search to the namespaces of its
547 arguments even if the namespace has not been imported.
557 Here the compiler will search for `foo' in the namespace of 'b'
558 and find A::foo. GDB now supports this. This construct is commonly
559 used in the Standard Template Library for operators.
561 ** Improved User Defined Operator Support
563 In addition to member operators, GDB now supports lookup of operators
564 defined in a namespace and imported with a `using' directive, operators
565 defined in the global scope, operators imported implicitly from an
566 anonymous namespace, and the ADL operators mentioned in the previous
568 GDB now also supports proper overload resolution for all the previously
569 mentioned flavors of operators.
571 ** static const class members
573 Printing of static const class members that are initialized in the
574 class definition has been fixed.
576 * Windows Thread Information Block access.
578 On Windows targets, GDB now supports displaying the Windows Thread
579 Information Block (TIB) structure. This structure is visible either
580 by using the new command `info w32 thread-information-block' or, by
581 dereferencing the new convenience variable named `$_tlb', a
582 thread-specific pointer to the TIB. This feature is also supported
583 when remote debugging using GDBserver.
587 Static tracepoints are calls in the user program into a tracing
588 library. One such library is a port of the LTTng kernel tracer to
589 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
590 When debugging with GDBserver, GDB now supports combining the GDB
591 tracepoint machinery with such libraries. For example: the user can
592 use GDB to probe a static tracepoint marker (a call from the user
593 program into the tracing library) with the new "strace" command (see
594 "New commands" below). This creates a "static tracepoint" in the
595 breakpoint list, that can be manipulated with the same feature set
596 as fast and regular tracepoints. E.g., collect registers, local and
597 global variables, collect trace state variables, and define
598 tracepoint conditions. In addition, the user can collect extra
599 static tracepoint marker specific data, by collecting the new
600 $_sdata internal variable. When analyzing the trace buffer, you can
601 inspect $_sdata like any other variable available to GDB. For more
602 information, see the "Tracepoints" chapter in GDB user manual. New
603 remote packets have been defined to support static tracepoints, see
604 the "New remote packets" section below.
606 * Better reconstruction of tracepoints after disconnected tracing
608 GDB will attempt to download the original source form of tracepoint
609 definitions when starting a trace run, and then will upload these
610 upon reconnection to the target, resulting in a more accurate
611 reconstruction of the tracepoints that are in use on the target.
615 You can now exercise direct control over the ways that GDB can
616 affect your program. For instance, you can disallow the setting of
617 breakpoints, so that the program can run continuously (assuming
618 non-stop mode). In addition, the "observer" variable is available
619 to switch all of the different controls; in observer mode, GDB
620 cannot affect the target's behavior at all, which is useful for
621 tasks like diagnosing live systems in the field.
623 * The new convenience variable $_thread holds the number of the
630 Return the address of the Windows Thread Information Block of a given thread.
634 In response to several of the tracepoint packets, the target may now
635 also respond with a number of intermediate `qRelocInsn' request
636 packets before the final result packet, to have GDB handle
637 relocating an instruction to execute at a different address. This
638 is particularly useful for stubs that support fast tracepoints. GDB
639 reports support for this feature in the qSupported packet.
643 List static tracepoint markers in the target program.
647 List static tracepoint markers at a given address in the target
650 qXfer:statictrace:read
652 Read the static trace data collected (by a `collect $_sdata'
653 tracepoint action). The remote stub reports support for this packet
654 to gdb's qSupported query.
658 Send the current settings of GDB's permission flags.
662 Send part of the source (textual) form of a tracepoint definition,
663 which includes location, conditional, and action list.
665 * The source command now accepts a -s option to force searching for the
666 script in the source search path even if the script name specifies
669 * New features in the GDB remote stub, GDBserver
671 - GDBserver now support tracepoints (including fast tracepoints, and
672 static tracepoints). The feature is currently supported by the
673 i386-linux and amd64-linux builds. See the "Tracepoints support
674 in gdbserver" section in the manual for more information.
676 GDBserver JIT compiles the tracepoint's conditional agent
677 expression bytecode into native code whenever possible for low
678 overhead dynamic tracepoints conditionals. For such tracepoints,
679 an expression that examines program state is evaluated when the
680 tracepoint is reached, in order to determine whether to capture
681 trace data. If the condition is simple and false, processing the
682 tracepoint finishes very quickly and no data is gathered.
684 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
685 for static tracepoints support.
687 - GDBserver now supports x86_64 Windows 64-bit debugging.
689 * GDB now sends xmlRegisters= in qSupported packet to indicate that
690 it understands register description.
692 * The --batch flag now disables pagination and queries.
694 * X86 general purpose registers
696 GDB now supports reading/writing byte, word and double-word x86
697 general purpose registers directly. This means you can use, say,
698 $ah or $ax to refer, respectively, to the byte register AH and
699 16-bit word register AX that are actually portions of the 32-bit
700 register EAX or 64-bit register RAX.
702 * The `commands' command now accepts a range of breakpoints to modify.
703 A plain `commands' following a command that creates multiple
704 breakpoints affects all the breakpoints set by that command. This
705 applies to breakpoints set by `rbreak', and also applies when a
706 single `break' command creates multiple breakpoints (e.g.,
707 breakpoints on overloaded c++ functions).
709 * The `rbreak' command now accepts a filename specification as part of
710 its argument, limiting the functions selected by the regex to those
711 in the specified file.
713 * Support for remote debugging Windows and SymbianOS shared libraries
714 from Unix hosts has been improved. Non Windows GDB builds now can
715 understand target reported file names that follow MS-DOS based file
716 system semantics, such as file names that include drive letters and
717 use the backslash character as directory separator. This makes it
718 possible to transparently use the "set sysroot" and "set
719 solib-search-path" on Unix hosts to point as host copies of the
720 target's shared libraries. See the new command "set
721 target-file-system-kind" described below, and the "Commands to
722 specify files" section in the user manual for more information.
726 eval template, expressions...
727 Convert the values of one or more expressions under the control
728 of the string template to a command line, and call it.
730 set target-file-system-kind unix|dos-based|auto
731 show target-file-system-kind
732 Set or show the assumed file system kind for target reported file
735 save breakpoints <filename>
736 Save all current breakpoint definitions to a file suitable for use
737 in a later debugging session. To read the saved breakpoint
738 definitions, use the `source' command.
740 `save tracepoints' is a new alias for `save-tracepoints'. The latter
743 info static-tracepoint-markers
744 Display information about static tracepoint markers in the target.
746 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
747 Define a static tracepoint by probing a marker at the given
748 function, line, address, or marker ID.
752 Enable and disable observer mode.
754 set may-write-registers on|off
755 set may-write-memory on|off
756 set may-insert-breakpoints on|off
757 set may-insert-tracepoints on|off
758 set may-insert-fast-tracepoints on|off
759 set may-interrupt on|off
760 Set individual permissions for GDB effects on the target. Note that
761 some of these settings can have undesirable or surprising
762 consequences, particularly when changed in the middle of a session.
763 For instance, disabling the writing of memory can prevent
764 breakpoints from being inserted, cause single-stepping to fail, or
765 even crash your program, if you disable after breakpoints have been
766 inserted. However, GDB should not crash.
768 set record memory-query on|off
769 show record memory-query
770 Control whether to stop the inferior if memory changes caused
771 by an instruction cannot be recorded.
776 The disassemble command now supports "start,+length" form of two arguments.
780 ** GDB now provides a new directory location, called the python directory,
781 where Python scripts written for GDB can be installed. The location
782 of that directory is <data-directory>/python, where <data-directory>
783 is the GDB data directory. For more details, see section `Scripting
784 GDB using Python' in the manual.
786 ** The GDB Python API now has access to breakpoints, symbols, symbol
787 tables, program spaces, inferiors, threads and frame's code blocks.
788 Additionally, GDB Parameters can now be created from the API, and
789 manipulated via set/show in the CLI.
791 ** New functions gdb.target_charset, gdb.target_wide_charset,
792 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
794 ** New exception gdb.GdbError.
796 ** Pretty-printers are now also looked up in the current program space.
798 ** Pretty-printers can now be individually enabled and disabled.
800 ** GDB now looks for names of Python scripts to auto-load in a
801 special section named `.debug_gdb_scripts', in addition to looking
802 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
804 * Tracepoint actions were unified with breakpoint commands. In particular,
805 there are no longer differences in "info break" output for breakpoints and
806 tracepoints and the "commands" command can be used for both tracepoints and
811 ARM Symbian arm*-*-symbianelf*
813 * D language support.
814 GDB now supports debugging programs written in the D programming
817 * GDB now supports the extended ptrace interface for PowerPC which is
818 available since Linux kernel version 2.6.34. This automatically enables
819 any hardware breakpoints and additional hardware watchpoints available in
820 the processor. The old ptrace interface exposes just one hardware
821 watchpoint and no hardware breakpoints.
823 * GDB is now able to use the Data Value Compare (DVC) register available on
824 embedded PowerPC processors to implement in hardware simple watchpoint
825 conditions of the form:
827 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
829 This works in native GDB running on Linux kernels with the extended ptrace
830 interface mentioned above.
832 *** Changes in GDB 7.1
838 GDB now supports importing of namespaces in C++. This enables the
839 user to inspect variables from imported namespaces. Support for
840 namepace aliasing has also been added. So, if a namespace is
841 aliased in the current scope (e.g. namepace C=A; ) the user can
842 print variables using the alias (e.g. (gdb) print C::x).
846 All known bugs relating to the printing of virtual base class were
847 fixed. It is now possible to call overloaded static methods using a
852 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
853 and reinterpret_cast<> are now handled by the C++ expression parser.
857 Xilinx MicroBlaze microblaze-*-*
862 Xilinx MicroBlaze microblaze
865 * Multi-program debugging.
867 GDB now has support for multi-program (a.k.a. multi-executable or
868 multi-exec) debugging. This allows for debugging multiple inferiors
869 simultaneously each running a different program under the same GDB
870 session. See "Debugging Multiple Inferiors and Programs" in the
871 manual for more information. This implied some user visible changes
872 in the multi-inferior support. For example, "info inferiors" now
873 lists inferiors that are not running yet or that have exited
874 already. See also "New commands" and "New options" below.
876 * New tracing features
878 GDB's tracepoint facility now includes several new features:
880 ** Trace state variables
882 GDB tracepoints now include support for trace state variables, which
883 are variables managed by the target agent during a tracing
884 experiment. They are useful for tracepoints that trigger each
885 other, so for instance one tracepoint can count hits in a variable,
886 and then a second tracepoint has a condition that is true when the
887 count reaches a particular value. Trace state variables share the
888 $-syntax of GDB convenience variables, and can appear in both
889 tracepoint actions and condition expressions. Use the "tvariable"
890 command to create, and "info tvariables" to view; see "Trace State
891 Variables" in the manual for more detail.
895 GDB now includes an option for defining fast tracepoints, which
896 targets may implement more efficiently, such as by installing a jump
897 into the target agent rather than a trap instruction. The resulting
898 speedup can be by two orders of magnitude or more, although the
899 tradeoff is that some program locations on some target architectures
900 might not allow fast tracepoint installation, for instance if the
901 instruction to be replaced is shorter than the jump. To request a
902 fast tracepoint, use the "ftrace" command, with syntax identical to
903 the regular trace command.
905 ** Disconnected tracing
907 It is now possible to detach GDB from the target while it is running
908 a trace experiment, then reconnect later to see how the experiment
909 is going. In addition, a new variable disconnected-tracing lets you
910 tell the target agent whether to continue running a trace if the
911 connection is lost unexpectedly.
915 GDB now has the ability to save the trace buffer into a file, and
916 then use that file as a target, similarly to you can do with
917 corefiles. You can select trace frames, print data that was
918 collected in them, and use tstatus to display the state of the
919 tracing run at the moment that it was saved. To create a trace
920 file, use "tsave <filename>", and to use it, do "target tfile
923 ** Circular trace buffer
925 You can ask the target agent to handle the trace buffer as a
926 circular buffer, discarding the oldest trace frames to make room for
927 newer ones, by setting circular-trace-buffer to on. This feature may
928 not be available for all target agents.
933 The disassemble command, when invoked with two arguments, now requires
934 the arguments to be comma-separated.
937 The info variables command now displays variable definitions. Files
938 which only declare a variable are not shown.
941 The source command is now capable of sourcing Python scripts.
942 This feature is dependent on the debugger being build with Python
945 Related to this enhancement is also the introduction of a new command
946 "set script-extension" (see below).
948 * New commands (for set/show, see "New options" below)
950 record save [<FILENAME>]
951 Save a file (in core file format) containing the process record
952 execution log for replay debugging at a later time.
954 record restore <FILENAME>
955 Restore the process record execution log that was saved at an
956 earlier time, for replay debugging.
958 add-inferior [-copies <N>] [-exec <FILENAME>]
961 clone-inferior [-copies <N>] [ID]
962 Make a new inferior ready to execute the same program another
968 maint info program-spaces
969 List the program spaces loaded into GDB.
971 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
972 show remote interrupt-sequence
973 Allow the user to select one of ^C, a BREAK signal or BREAK-g
974 as the sequence to the remote target in order to interrupt the execution.
975 Ctrl-C is a default. Some system prefers BREAK which is high level of
976 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
977 Magic SysRq g. It is BREAK signal and character 'g'.
979 set remote interrupt-on-connect [on | off]
980 show remote interrupt-on-connect
981 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
982 remote target when gdb connects to it. This is needed when you debug
985 set remotebreak [on | off]
987 Deprecated. Use "set/show remote interrupt-sequence" instead.
989 tvariable $NAME [ = EXP ]
990 Create or modify a trace state variable.
993 List trace state variables and their values.
995 delete tvariable $NAME ...
996 Delete one or more trace state variables.
999 Evaluate the given expressions without collecting anything into the
1000 trace buffer. (Valid in tracepoint actions only.)
1002 ftrace FN / FILE:LINE / *ADDR
1003 Define a fast tracepoint at the given function, line, or address.
1005 * New expression syntax
1007 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1008 GDB now parses 0b101010 identically with 42.
1012 set follow-exec-mode new|same
1013 show follow-exec-mode
1014 Control whether GDB reuses the same inferior across an exec call or
1015 creates a new one. This is useful to be able to restart the old
1016 executable after the inferior having done an exec call.
1018 set default-collect EXPR, ...
1019 show default-collect
1020 Define a list of expressions to be collected at each tracepoint.
1021 This is a useful way to ensure essential items are not overlooked,
1022 such as registers or a critical global variable.
1024 set disconnected-tracing
1025 show disconnected-tracing
1026 If set to 1, the target is instructed to continue tracing if it
1027 loses its connection to GDB. If 0, the target is to stop tracing
1030 set circular-trace-buffer
1031 show circular-trace-buffer
1032 If set to on, the target is instructed to use a circular trace buffer
1033 and discard the oldest trace frames instead of stopping the trace due
1034 to a full trace buffer. If set to off, the trace stops when the buffer
1035 fills up. Some targets may not support this.
1037 set script-extension off|soft|strict
1038 show script-extension
1039 If set to "off", the debugger does not perform any script language
1040 recognition, and all sourced files are assumed to be GDB scripts.
1041 If set to "soft" (the default), files are sourced according to
1042 filename extension, falling back to GDB scripts if the first
1044 If set to "strict", files are sourced according to filename extension.
1046 set ada trust-PAD-over-XVS on|off
1047 show ada trust-PAD-over-XVS
1048 If off, activate a workaround against a bug in the debugging information
1049 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1050 the GCC sources for more information about the GNAT encoding and
1051 PAD types in particular). It is always safe to set this option to
1052 off, but this introduces a slight performance penalty. The default
1055 * Python API Improvements
1057 ** GDB provides the new class gdb.LazyString. This is useful in
1058 some pretty-printing cases. The new method gdb.Value.lazy_string
1059 provides a simple way to create objects of this type.
1061 ** The fields returned by gdb.Type.fields now have an
1062 `is_base_class' attribute.
1064 ** The new method gdb.Type.range returns the range of an array type.
1066 ** The new method gdb.parse_and_eval can be used to parse and
1067 evaluate an expression.
1069 * New remote packets
1072 Define a trace state variable.
1075 Get the current value of a trace state variable.
1078 Set desired tracing behavior upon disconnection.
1081 Set the trace buffer to be linear or circular.
1084 Get data about the tracepoints currently in use.
1088 Process record now works correctly with hardware watchpoints.
1090 Multiple bug fixes have been made to the mips-irix port, making it
1091 much more reliable. In particular:
1092 - Debugging threaded applications is now possible again. Previously,
1093 GDB would hang while starting the program, or while waiting for
1094 the program to stop at a breakpoint.
1095 - Attaching to a running process no longer hangs.
1096 - An error occurring while loading a core file has been fixed.
1097 - Changing the value of the PC register now works again. This fixes
1098 problems observed when using the "jump" command, or when calling
1099 a function from GDB, or even when assigning a new value to $pc.
1100 - With the "finish" and "return" commands, the return value for functions
1101 returning a small array is now correctly printed.
1102 - It is now possible to break on shared library code which gets executed
1103 during a shared library init phase (code executed while executing
1104 their .init section). Previously, the breakpoint would have no effect.
1105 - GDB is now able to backtrace through the signal handler for
1106 non-threaded programs.
1108 PIE (Position Independent Executable) programs debugging is now supported.
1109 This includes debugging execution of PIC (Position Independent Code) shared
1110 libraries although for that, it should be possible to run such libraries as an
1113 *** Changes in GDB 7.0
1115 * GDB now has an interface for JIT compilation. Applications that
1116 dynamically generate code can create symbol files in memory and register
1117 them with GDB. For users, the feature should work transparently, and
1118 for JIT developers, the interface is documented in the GDB manual in the
1119 "JIT Compilation Interface" chapter.
1121 * Tracepoints may now be conditional. The syntax is as for
1122 breakpoints; either an "if" clause appended to the "trace" command,
1123 or the "condition" command is available. GDB sends the condition to
1124 the target for evaluation using the same bytecode format as is used
1125 for tracepoint actions.
1127 * The disassemble command now supports: an optional /r modifier, print the
1128 raw instructions in hex as well as in symbolic form, and an optional /m
1129 modifier to print mixed source+assembly.
1131 * Process record and replay
1133 In a architecture environment that supports ``process record and
1134 replay'', ``process record and replay'' target can record a log of
1135 the process execution, and replay it with both forward and reverse
1138 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1139 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1140 set execution-direction {forward|reverse}, for targets that support
1143 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1144 feature is available with a native GDB running on kernel version
1147 * GDB now has support for multi-byte and wide character sets on the
1148 target. Strings whose character type is wchar_t, char16_t, or
1149 char32_t are now correctly printed. GDB supports wide- and unicode-
1150 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1151 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1152 `printf'. This feature requires iconv to work properly; if your
1153 system does not have a working iconv, GDB can use GNU libiconv. See
1154 the installation instructions for more information.
1156 * GDB now supports automatic retrieval of shared library files from
1157 remote targets. To use this feature, specify a system root that begins
1158 with the `remote:' prefix, either via the `set sysroot' command or via
1159 the `--with-sysroot' configure-time option.
1161 * "info sharedlibrary" now takes an optional regex of libraries to show,
1162 and it now reports if a shared library has no debugging information.
1164 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1165 now complete on file names.
1167 * When completing in expressions, gdb will attempt to limit
1168 completions to allowable structure or union fields, where appropriate.
1169 For instance, consider:
1171 # struct example { int f1; double f2; };
1172 # struct example variable;
1175 If the user types TAB at the end of this command line, the available
1176 completions will be "f1" and "f2".
1178 * Inlined functions are now supported. They show up in backtraces, and
1179 the "step", "next", and "finish" commands handle them automatically.
1181 * GDB now supports the token-splicing (##) and stringification (#)
1182 operators when expanding macros. It also supports variable-arity
1185 * GDB now supports inspecting extra signal information, exported by
1186 the new $_siginfo convenience variable. The feature is currently
1187 implemented on linux ARM, i386 and amd64.
1189 * GDB can now display the VFP floating point registers and NEON vector
1190 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1191 can provide these registers (requires Linux 2.6.30 or later). Remote
1192 and simulator targets may also provide them.
1194 * New remote packets
1197 Search memory for a sequence of bytes.
1200 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1201 operation over reliable transport links. Use of this packet is
1202 controlled by the `set remote noack-packet' command.
1205 Kill the process with the specified process ID. Use this in preference
1206 to `k' when multiprocess protocol extensions are supported.
1209 Obtains additional operating system information
1213 Read or write additional signal information.
1215 * Removed remote protocol undocumented extension
1217 An undocumented extension to the remote protocol's `S' stop reply
1218 packet that permited the stub to pass a process id was removed.
1219 Remote servers should use the `T' stop reply packet instead.
1221 * GDB now supports multiple function calling conventions according to the
1222 DWARF-2 DW_AT_calling_convention function attribute.
1224 * The SH target utilizes the aforementioned change to distinguish between gcc
1225 and Renesas calling convention. It also adds the new CLI commands
1226 `set/show sh calling-convention'.
1228 * GDB can now read compressed debug sections, as produced by GNU gold
1229 with the --compress-debug-sections=zlib flag.
1231 * 64-bit core files are now supported on AIX.
1233 * Thread switching is now supported on Tru64.
1235 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1236 which will be allocated using malloc later in program execution.
1238 * The qXfer:libraries:read remote procotol packet now allows passing a
1239 list of section offsets.
1241 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1242 conditions handling signals delivered during attach or thread creation
1243 have also been fixed.
1245 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1246 From the user's standpoint, all unqualified instances of True and False
1247 are treated as the standard definitions, regardless of context.
1249 * GDB now parses C++ symbol and type names more flexibly. For
1252 template<typename T> class C { };
1255 GDB will now correctly handle all of:
1257 ptype C<char const *>
1258 ptype C<char const*>
1259 ptype C<const char *>
1260 ptype C<const char*>
1262 * New features in the GDB remote stub, gdbserver
1264 - The "--wrapper" command-line argument tells gdbserver to use a
1265 wrapper program to launch programs for debugging.
1267 - On PowerPC and S/390 targets, it is now possible to use a single
1268 gdbserver executable to debug both 32-bit and 64-bit programs.
1269 (This requires gdbserver itself to be built as a 64-bit executable.)
1271 - gdbserver uses the new noack protocol mode for TCP connections to
1272 reduce communications latency, if also supported and enabled in GDB.
1274 - Support for the sparc64-linux-gnu target is now included in
1277 - The amd64-linux build of gdbserver now supports debugging both
1278 32-bit and 64-bit programs.
1280 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1281 now support hardware watchpoints, and will use them automatically
1286 GDB now has support for scripting using Python. Whether this is
1287 available is determined at configure time.
1289 New GDB commands can now be written in Python.
1291 * Ada tasking support
1293 Ada tasks can now be inspected in GDB. The following commands have
1297 Print the list of Ada tasks.
1299 Print detailed information about task number N.
1301 Print the task number of the current task.
1303 Switch the context of debugging to task number N.
1305 * Support for user-defined prefixed commands. The "define" command can
1306 add new commands to existing prefixes, e.g. "target".
1308 * Multi-inferior, multi-process debugging.
1310 GDB now has generalized support for multi-inferior debugging. See
1311 "Debugging Multiple Inferiors" in the manual for more information.
1312 Although availability still depends on target support, the command
1313 set is more uniform now. The GNU/Linux specific multi-forks support
1314 has been migrated to this new framework. This implied some user
1315 visible changes; see "New commands" and also "Removed commands"
1318 * Target descriptions can now describe the target OS ABI. See the
1319 "Target Description Format" section in the user manual for more
1322 * Target descriptions can now describe "compatible" architectures
1323 to indicate that the target can execute applications for a different
1324 architecture in addition to those for the main target architecture.
1325 See the "Target Description Format" section in the user manual for
1328 * Multi-architecture debugging.
1330 GDB now includes general supports for debugging applications on
1331 hybrid systems that use more than one single processor architecture
1332 at the same time. Each such hybrid architecture still requires
1333 specific support to be added. The only hybrid architecture supported
1334 in this version of GDB is the Cell Broadband Engine.
1336 * GDB now supports integrated debugging of Cell/B.E. applications that
1337 use both the PPU and SPU architectures. To enable support for hybrid
1338 Cell/B.E. debugging, you need to configure GDB to support both the
1339 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1340 --enable-targets configure option.
1342 * Non-stop mode debugging.
1344 For some targets, GDB now supports an optional mode of operation in
1345 which you can examine stopped threads while other threads continue
1346 to execute freely. This is referred to as non-stop mode, with the
1347 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1348 section in the user manual for more information.
1350 To be able to support remote non-stop debugging, a remote stub needs
1351 to implement the non-stop mode remote protocol extensions, as
1352 described in the "Remote Non-Stop" section of the user manual. The
1353 GDB remote stub, gdbserver, has been adjusted to support these
1354 extensions on linux targets.
1356 * New commands (for set/show, see "New options" below)
1358 catch syscall [NAME(S) | NUMBER(S)]
1359 Catch system calls. Arguments, which should be names of system
1360 calls or their numbers, mean catch only those syscalls. Without
1361 arguments, every syscall will be caught. When the inferior issues
1362 any of the specified syscalls, GDB will stop and announce the system
1363 call, both when it is called and when its call returns. This
1364 feature is currently available with a native GDB running on the
1365 Linux Kernel, under the following architectures: x86, x86_64,
1366 PowerPC and PowerPC64.
1368 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1370 Search memory for a sequence of bytes.
1372 maint set python print-stack
1373 maint show python print-stack
1374 Show a stack trace when an error is encountered in a Python script.
1377 Invoke CODE by passing it to the Python interpreter.
1382 These allow macros to be defined, undefined, and listed
1386 Show operating system information about processes.
1389 List the inferiors currently under GDB's control.
1392 Switch focus to inferior number NUM.
1395 Detach from inferior number NUM.
1398 Kill inferior number NUM.
1402 set spu stop-on-load
1403 show spu stop-on-load
1404 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1406 set spu auto-flush-cache
1407 show spu auto-flush-cache
1408 Control whether to automatically flush the software-managed cache
1409 during Cell/B.E. debugging.
1411 set sh calling-convention
1412 show sh calling-convention
1413 Control the calling convention used when calling SH target functions.
1416 show debug timestamp
1417 Control display of timestamps with GDB debugging output.
1419 set disassemble-next-line
1420 show disassemble-next-line
1421 Control display of disassembled source lines or instructions when
1424 set remote noack-packet
1425 show remote noack-packet
1426 Set/show the use of remote protocol QStartNoAckMode packet. See above
1427 under "New remote packets."
1429 set remote query-attached-packet
1430 show remote query-attached-packet
1431 Control use of remote protocol `qAttached' (query-attached) packet.
1433 set remote read-siginfo-object
1434 show remote read-siginfo-object
1435 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1438 set remote write-siginfo-object
1439 show remote write-siginfo-object
1440 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1443 set remote reverse-continue
1444 show remote reverse-continue
1445 Control use of remote protocol 'bc' (reverse-continue) packet.
1447 set remote reverse-step
1448 show remote reverse-step
1449 Control use of remote protocol 'bs' (reverse-step) packet.
1451 set displaced-stepping
1452 show displaced-stepping
1453 Control displaced stepping mode. Displaced stepping is a way to
1454 single-step over breakpoints without removing them from the debuggee.
1455 Also known as "out-of-line single-stepping".
1458 show debug displaced
1459 Control display of debugging info for displaced stepping.
1461 maint set internal-error
1462 maint show internal-error
1463 Control what GDB does when an internal error is detected.
1465 maint set internal-warning
1466 maint show internal-warning
1467 Control what GDB does when an internal warning is detected.
1472 Use a wrapper program to launch programs for debugging.
1474 set multiple-symbols (all|ask|cancel)
1475 show multiple-symbols
1476 The value of this variable can be changed to adjust the debugger behavior
1477 when an expression or a breakpoint location contains an ambiguous symbol
1478 name (an overloaded function name, for instance).
1480 set breakpoint always-inserted
1481 show breakpoint always-inserted
1482 Keep breakpoints always inserted in the target, as opposed to inserting
1483 them when resuming the target, and removing them when the target stops.
1484 This option can improve debugger performance on slow remote targets.
1486 set arm fallback-mode (arm|thumb|auto)
1487 show arm fallback-mode
1488 set arm force-mode (arm|thumb|auto)
1490 These commands control how ARM GDB determines whether instructions
1491 are ARM or Thumb. The default for both settings is auto, which uses
1492 the current CPSR value for instructions without symbols; previous
1493 versions of GDB behaved as if "set arm fallback-mode arm".
1495 set disable-randomization
1496 show disable-randomization
1497 Standalone programs run with the virtual address space randomization enabled
1498 by default on some platforms. This option keeps the addresses stable across
1499 multiple debugging sessions.
1503 Control whether other threads are stopped or not when some thread hits
1508 Requests that asynchronous execution is enabled in the target, if available.
1509 In this case, it's possible to resume target in the background, and interact
1510 with GDB while the target is running. "show target-async" displays the
1511 current state of asynchronous execution of the target.
1513 set target-wide-charset
1514 show target-wide-charset
1515 The target-wide-charset is the name of the character set that GDB
1516 uses when printing characters whose type is wchar_t.
1518 set tcp auto-retry (on|off)
1520 set tcp connect-timeout
1521 show tcp connect-timeout
1522 These commands allow GDB to retry failed TCP connections to a remote stub
1523 with a specified timeout period; this is useful if the stub is launched
1524 in parallel with GDB but may not be ready to accept connections immediately.
1526 set libthread-db-search-path
1527 show libthread-db-search-path
1528 Control list of directories which GDB will search for appropriate
1531 set schedule-multiple (on|off)
1532 show schedule-multiple
1533 Allow GDB to resume all threads of all processes or only threads of
1534 the current process.
1538 Use more aggressive caching for accesses to the stack. This improves
1539 performance of remote debugging (particularly backtraces) without
1540 affecting correctness.
1542 set interactive-mode (on|off|auto)
1543 show interactive-mode
1544 Control whether GDB runs in interactive mode (on) or not (off).
1545 When in interactive mode, GDB waits for the user to answer all
1546 queries. Otherwise, GDB does not wait and assumes the default
1547 answer. When set to auto (the default), GDB determines which
1548 mode to use based on the stdin settings.
1553 For program forks, this is replaced by the new more generic `info
1554 inferiors' command. To list checkpoints, you can still use the
1555 `info checkpoints' command, which was an alias for the `info forks'
1559 Replaced by the new `inferior' command. To switch between
1560 checkpoints, you can still use the `restart' command, which was an
1561 alias for the `fork' command.
1564 This is removed, since some targets don't have a notion of
1565 processes. To switch between processes, you can still use the
1566 `inferior' command using GDB's own inferior number.
1569 For program forks, this is replaced by the new more generic `kill
1570 inferior' command. To delete a checkpoint, you can still use the
1571 `delete checkpoint' command, which was an alias for the `delete
1575 For program forks, this is replaced by the new more generic `detach
1576 inferior' command. To detach a checkpoint, you can still use the
1577 `detach checkpoint' command, which was an alias for the `detach
1580 * New native configurations
1582 x86/x86_64 Darwin i[34567]86-*-darwin*
1584 x86_64 MinGW x86_64-*-mingw*
1588 Lattice Mico32 lm32-*
1589 x86 DICOS i[34567]86-*-dicos*
1590 x86_64 DICOS x86_64-*-dicos*
1593 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1594 (mingw32ce) debugging.
1600 These commands were actually not implemented on any target.
1602 *** Changes in GDB 6.8
1604 * New native configurations
1606 NetBSD/hppa hppa*-*netbsd*
1607 Xtensa GNU/Linux xtensa*-*-linux*
1611 NetBSD/hppa hppa*-*-netbsd*
1612 Xtensa GNU/Lunux xtensa*-*-linux*
1614 * Change in command line behavior -- corefiles vs. process ids.
1616 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1617 attaching to process NUMBER fails, GDB no longer attempts to open a
1618 core file named NUMBER. Attaching to a program using the -c option
1619 is no longer supported. Instead, use the '-p' or '--pid' options.
1621 * GDB can now be built as a native debugger for debugging Windows x86
1622 (mingw32) Portable Executable (PE) programs.
1624 * Pending breakpoints no longer change their number when their address
1627 * GDB now supports breakpoints with multiple locations,
1628 including breakpoints on C++ constructors, inside C++ templates,
1629 and in inlined functions.
1631 * GDB's ability to debug optimized code has been improved. GDB more
1632 accurately identifies function bodies and lexical blocks that occupy
1633 more than one contiguous range of addresses.
1635 * Target descriptions can now describe registers for PowerPC.
1637 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1638 registers on PowerPC targets.
1640 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1641 targets even when the libthread_db library is not available.
1643 * The GDB remote stub, gdbserver, now supports the new file transfer
1644 commands (remote put, remote get, and remote delete).
1646 * The GDB remote stub, gdbserver, now supports run and attach in
1647 extended-remote mode.
1649 * hppa*64*-*-hpux11* target broken
1650 The debugger is unable to start a program and fails with the following
1651 error: "Error trying to get information about dynamic linker".
1652 The gdb-6.7 release is also affected.
1654 * GDB now supports the --enable-targets= configure option to allow
1655 building a single GDB executable that supports multiple remote
1656 target architectures.
1658 * GDB now supports debugging C and C++ programs which use the
1659 Decimal Floating Point extension. In addition, the PowerPC target
1660 now has a set of pseudo-registers to inspect decimal float values
1661 stored in two consecutive float registers.
1663 * The -break-insert MI command can optionally create pending
1666 * Improved support for debugging Ada
1667 Many improvements to the Ada language support have been made. These
1669 - Better support for Ada2005 interface types
1670 - Improved handling of arrays and slices in general
1671 - Better support for Taft-amendment types
1672 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1674 - Improved command completion in Ada
1677 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1682 set print frame-arguments (all|scalars|none)
1683 show print frame-arguments
1684 The value of this variable can be changed to control which argument
1685 values should be printed by the debugger when displaying a frame.
1690 Transfer files to and from a remote target, and delete remote files.
1697 Transfer files to and from a remote target, and delete remote files.
1699 * New remote packets
1706 Open, close, read, write, and delete files on the remote system.
1709 Attach to an existing process on the remote system, in extended-remote
1713 Run a new process on the remote system, in extended-remote mode.
1715 *** Changes in GDB 6.7
1717 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1718 bfd, libiberty and opcodes, as revealed by static analysis donated by
1719 Coverity, Inc. (http://scan.coverity.com).
1721 * When looking up multiply-defined global symbols, GDB will now prefer the
1722 symbol definition in the current shared library if it was built using the
1723 -Bsymbolic linker option.
1725 * When the Text User Interface (TUI) is not configured, GDB will now
1726 recognize the -tui command-line option and print a message that the TUI
1729 * The GDB remote stub, gdbserver, now has lower overhead for high
1730 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1732 * GDB for MIPS targets now autodetects whether a remote target provides
1733 32-bit or 64-bit register values.
1735 * Support for C++ member pointers has been improved.
1737 * GDB now understands XML target descriptions, which specify the
1738 target's overall architecture. GDB can read a description from
1739 a local file or over the remote serial protocol.
1741 * Vectors of single-byte data use a new integer type which is not
1742 automatically displayed as character or string data.
1744 * The /s format now works with the print command. It displays
1745 arrays of single-byte integers and pointers to single-byte integers
1748 * Target descriptions can now describe target-specific registers,
1749 for architectures which have implemented the support (currently
1750 only ARM, M68K, and MIPS).
1752 * GDB and the GDB remote stub, gdbserver, now support the XScale
1755 * The GDB remote stub, gdbserver, has been updated to support
1756 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1757 has been rewritten to use the standard GDB remote protocol.
1759 * GDB can now step into C++ functions which are called through thunks.
1761 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1763 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1764 layout. It also supports a TextSeg= and DataSeg= response when only
1765 segment base addresses (rather than offsets) are available.
1767 * The /i format now outputs any trailing branch delay slot instructions
1768 immediately following the last instruction within the count specified.
1770 * The GDB remote protocol "T" stop reply packet now supports a
1771 "library" response. Combined with the new "qXfer:libraries:read"
1772 packet, this response allows GDB to debug shared libraries on targets
1773 where the operating system manages the list of loaded libraries (e.g.
1774 Windows and SymbianOS).
1776 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1777 (DLLs) on Windows and Windows CE targets.
1779 * GDB now supports a faster verification that a .debug file matches its binary
1780 according to its build-id signature, if the signature is present.
1786 Enable or disable hardware flow control (RTS/CTS) on the serial port
1787 when debugging using remote targets.
1789 set mem inaccessible-by-default
1790 show mem inaccessible-by-default
1791 If the target supplies a memory map, for instance via the remote
1792 protocol's "qXfer:memory-map:read" packet, setting this variable
1793 prevents GDB from accessing memory outside the memory map. This
1794 is useful for targets with memory mapped registers or which react
1795 badly to accesses of unmapped address space.
1797 set breakpoint auto-hw
1798 show breakpoint auto-hw
1799 If the target supplies a memory map, for instance via the remote
1800 protocol's "qXfer:memory-map:read" packet, setting this variable
1801 lets GDB use hardware breakpoints automatically for memory regions
1802 where it can not use software breakpoints. This covers both the
1803 "break" command and internal breakpoints used for other commands
1804 including "next" and "finish".
1807 catch exception unhandled
1808 Stop the program execution when Ada exceptions are raised.
1811 Stop the program execution when an Ada assertion failed.
1815 Set an alternate system root for target files. This is a more
1816 general version of "set solib-absolute-prefix", which is now
1817 an alias to "set sysroot".
1820 Provide extended SPU facility status information. This set of
1821 commands is available only when debugging the Cell/B.E. SPU
1824 * New native configurations
1826 OpenBSD/sh sh*-*openbsd*
1829 unset tdesc filename
1831 Use the specified local file as an XML target description, and do
1832 not query the target for its built-in description.
1836 OpenBSD/sh sh*-*-openbsd*
1837 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1838 Toshiba Media Processor mep-elf
1840 * New remote packets
1843 Ignore the specified signals; pass them directly to the debugged program
1844 without stopping other threads or reporting them to GDB.
1846 qXfer:features:read:
1847 Read an XML target description from the target, which describes its
1852 Read or write contents of an spufs file on the target system. These
1853 packets are available only on the Cell/B.E. SPU architecture.
1855 qXfer:libraries:read:
1856 Report the loaded shared libraries. Combined with new "T" packet
1857 response, this packet allows GDB to debug shared libraries on
1858 targets where the operating system manages the list of loaded
1859 libraries (e.g. Windows and SymbianOS).
1863 Support for these obsolete configurations has been removed.
1871 i[34567]86-*-lynxos*
1872 i[34567]86-*-netware*
1873 i[34567]86-*-sco3.2v5*
1874 i[34567]86-*-sco3.2v4*
1876 i[34567]86-*-sysv4.2*
1879 i[34567]86-*-unixware2*
1880 i[34567]86-*-unixware*
1889 * Other removed features
1896 Various m68k-only ROM monitors.
1903 Various Renesas ROM monitors and debugging interfaces for SH and
1908 Support for a Macraigor serial interface to on-chip debugging.
1909 GDB does not directly support the newer parallel or USB
1914 A debug information format. The predecessor to DWARF 2 and
1915 DWARF 3, which are still supported.
1917 Support for the HP aCC compiler on HP-UX/PA-RISC
1919 SOM-encapsulated symbolic debugging information, automatic
1920 invocation of pxdb, and the aCC custom C++ ABI. This does not
1921 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1922 with aCC can still be debugged on an assembly level.
1924 MIPS ".pdr" sections
1926 A MIPS-specific format used to describe stack frame layout
1927 in debugging information.
1931 GDB could work with an older version of Guile to debug
1932 the interpreter and Scheme programs running in it.
1934 set mips stack-arg-size
1935 set mips saved-gpreg-size
1937 Use "set mips abi" to control parameter passing for MIPS.
1939 *** Changes in GDB 6.6
1944 Cell Broadband Engine SPU spu-elf
1946 * GDB can now be configured as a cross-debugger targeting native Windows
1947 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1948 running on a Windows system over TCP/IP to debug Windows programs.
1950 * The GDB remote stub, gdbserver, has been updated to support Windows and
1951 Cygwin debugging. Both single-threaded and multi-threaded programs are
1954 * The "set trust-readonly-sections" command works again. This command was
1955 broken in GDB 6.3, 6.4, and 6.5.
1957 * The "load" command now supports writing to flash memory, if the remote
1958 stub provides the required support.
1960 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1961 longer requires symbolic debug information (e.g. DWARF-2).
1966 unset substitute-path
1967 show substitute-path
1968 Manage a list of substitution rules that GDB uses to rewrite the name
1969 of the directories where the sources are located. This can be useful
1970 for instance when the sources were moved to a different location
1971 between compilation and debugging.
1975 Print each CLI command as it is executed. Each command is prefixed with
1976 a number of `+' symbols representing the nesting depth.
1977 The source command now has a `-v' option to enable the same feature.
1981 The ARM Demon monitor support (RDP protocol, "target rdp").
1983 Kernel Object Display, an embedded debugging feature which only worked with
1984 an obsolete version of Cisco IOS.
1986 The 'set download-write-size' and 'show download-write-size' commands.
1988 * New remote packets
1991 Tell a stub about GDB client features, and request remote target features.
1992 The first feature implemented is PacketSize, which allows the target to
1993 specify the size of packets it can handle - to minimize the number of
1994 packets required and improve performance when connected to a remote
1998 Fetch an OS auxilliary vector from the remote stub. This packet is a
1999 more efficient replacement for qPart:auxv:read.
2001 qXfer:memory-map:read:
2002 Fetch a memory map from the remote stub, including information about
2003 RAM, ROM, and flash memory devices.
2008 Erase and program a flash memory device.
2010 * Removed remote packets
2013 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2014 used it, and only gdbserver implemented it.
2016 *** Changes in GDB 6.5
2020 Renesas M32C/M16C m32c-elf
2022 Morpho Technologies ms1 ms1-elf
2026 init-if-undefined Initialize a convenience variable, but
2027 only if it doesn't already have a value.
2029 The following commands are presently only implemented for native GNU/Linux:
2031 checkpoint Save a snapshot of the program state.
2033 restart <n> Return the program state to a
2034 previously saved state.
2036 info checkpoints List currently saved checkpoints.
2038 delete-checkpoint <n> Delete a previously saved checkpoint.
2040 set|show detach-on-fork Tell gdb whether to detach from a newly
2041 forked process, or to keep debugging it.
2043 info forks List forks of the user program that
2044 are available to be debugged.
2046 fork <n> Switch to debugging one of several
2047 forks of the user program that are
2048 available to be debugged.
2050 delete-fork <n> Delete a fork from the list of forks
2051 that are available to be debugged (and
2052 kill the forked process).
2054 detach-fork <n> Delete a fork from the list of forks
2055 that are available to be debugged (and
2056 allow the process to continue).
2060 Morpho Technologies ms2 ms1-elf
2062 * Improved Windows host support
2064 GDB now builds as a cross debugger hosted on i686-mingw32, including
2065 native console support, and remote communications using either
2066 network sockets or serial ports.
2068 * Improved Modula-2 language support
2070 GDB can now print most types in the Modula-2 syntax. This includes:
2071 basic types, set types, record types, enumerated types, range types,
2072 pointer types and ARRAY types. Procedure var parameters are correctly
2073 printed and hexadecimal addresses and character constants are also
2074 written in the Modula-2 syntax. Best results can be obtained by using
2075 GNU Modula-2 together with the -gdwarf-2 command line option.
2079 The ARM rdi-share module.
2081 The Netware NLM debug server.
2083 *** Changes in GDB 6.4
2085 * New native configurations
2087 OpenBSD/arm arm*-*-openbsd*
2088 OpenBSD/mips64 mips64-*-openbsd*
2092 Morpho Technologies ms1 ms1-elf
2094 * New command line options
2096 --batch-silent As for --batch, but totally silent.
2097 --return-child-result The debugger will exist with the same value
2098 the child (debugged) program exited with.
2099 --eval-command COMMAND, -ex COMMAND
2100 Execute a single GDB CLI command. This may be
2101 specified multiple times and in conjunction
2102 with the --command (-x) option.
2104 * Deprecated commands removed
2106 The following commands, that were deprecated in 2000, have been
2110 set|show arm disassembly-flavor set|show arm disassembler
2111 othernames set arm disassembler
2112 set|show remotedebug set|show debug remote
2113 set|show archdebug set|show debug arch
2114 set|show eventdebug set|show debug event
2117 * New BSD user-level threads support
2119 It is now possible to debug programs using the user-level threads
2120 library on OpenBSD and FreeBSD. Currently supported (target)
2123 FreeBSD/amd64 x86_64-*-freebsd*
2124 FreeBSD/i386 i386-*-freebsd*
2125 OpenBSD/i386 i386-*-openbsd*
2127 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2128 are not yet supported.
2130 * New support for Matsushita MN10300 w/sim added
2131 (Work in progress). mn10300-elf.
2133 * REMOVED configurations and files
2135 VxWorks and the XDR protocol *-*-vxworks
2136 Motorola MCORE mcore-*-*
2137 National Semiconductor NS32000 ns32k-*-*
2139 * New "set print array-indexes" command
2141 After turning this setting "on", GDB prints the index of each element
2142 when displaying arrays. The default is "off" to preserve the previous
2145 * VAX floating point support
2147 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2149 * User-defined command support
2151 In addition to using $arg0..$arg9 for argument passing, it is now possible
2152 to use $argc to determine now many arguments have been passed. See the
2153 section on user-defined commands in the user manual for more information.
2155 *** Changes in GDB 6.3:
2157 * New command line option
2159 GDB now accepts -l followed by a number to set the timeout for remote
2162 * GDB works with GCC -feliminate-dwarf2-dups
2164 GDB now supports a more compact representation of DWARF-2 debug
2165 information using DW_FORM_ref_addr references. These are produced
2166 by GCC with the option -feliminate-dwarf2-dups and also by some
2167 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2168 to use -feliminate-dwarf2-dups.
2170 * Internationalization
2172 When supported by the host system, GDB will be built with
2173 internationalization (libintl). The task of marking up the sources is
2174 continued, we're looking forward to our first translation.
2178 Initial support for debugging programs compiled with the GNAT
2179 implementation of the Ada programming language has been integrated
2180 into GDB. In this release, support is limited to expression evaluation.
2182 * New native configurations
2184 GNU/Linux/m32r m32r-*-linux-gnu
2188 GDB's remote protocol now includes support for the 'p' packet. This
2189 packet is used to fetch individual registers from a remote inferior.
2191 * END-OF-LIFE registers[] compatibility module
2193 GDB's internal register infrastructure has been completely rewritten.
2194 The new infrastructure making possible the implementation of key new
2195 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2198 GDB 6.3 will be the last release to include the the registers[]
2199 compatibility module that allowed out-of-date configurations to
2200 continue to work. This change directly impacts the following
2210 powerpc bdm protocol
2212 Unless there is activity to revive these configurations, they will be
2213 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2215 * OBSOLETE configurations and files
2217 Configurations that have been declared obsolete in this release have
2218 been commented out. Unless there is activity to revive these
2219 configurations, the next release of GDB will have their sources
2220 permanently REMOVED.
2229 *** Changes in GDB 6.2.1:
2231 * MIPS `break main; run' gave an heuristic-fence-post warning
2233 When attempting to run even a simple program, a warning about
2234 heuristic-fence-post being hit would be reported. This problem has
2237 * MIPS IRIX 'long double' crashed GDB
2239 When examining a long double variable, GDB would get a segmentation
2240 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2241 IRIX long double values).
2245 A bug in the VAX stack code was causing problems with the "next"
2246 command. This problem has been fixed.
2248 *** Changes in GDB 6.2:
2250 * Fix for ``many threads''
2252 On GNU/Linux systems that use the NPTL threads library, a program
2253 rapidly creating and deleting threads would confuse GDB leading to the
2256 ptrace: No such process.
2257 thread_db_get_info: cannot get thread info: generic error
2259 This problem has been fixed.
2261 * "-async" and "-noasync" options removed.
2263 Support for the broken "-noasync" option has been removed (it caused
2266 * New ``start'' command.
2268 This command runs the program until the begining of the main procedure.
2270 * New BSD Kernel Data Access Library (libkvm) interface
2272 Using ``target kvm'' it is now possible to debug kernel core dumps and
2273 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2274 platforms. Currently supported (native-only) configurations are:
2276 FreeBSD/amd64 x86_64-*-freebsd*
2277 FreeBSD/i386 i?86-*-freebsd*
2278 NetBSD/i386 i?86-*-netbsd*
2279 NetBSD/m68k m68*-*-netbsd*
2280 NetBSD/sparc sparc-*-netbsd*
2281 OpenBSD/amd64 x86_64-*-openbsd*
2282 OpenBSD/i386 i?86-*-openbsd*
2283 OpenBSD/m68k m68*-openbsd*
2284 OpenBSD/sparc sparc-*-openbsd*
2286 * Signal trampoline code overhauled
2288 Many generic problems with GDB's signal handling code have been fixed.
2289 These include: backtraces through non-contiguous stacks; recognition
2290 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2291 call; backtrace through a signal trampoline; step into and out of
2292 signal handlers; and single-stepping in the signal trampoline.
2294 Please note that kernel bugs are a limiting factor here. These
2295 features have been shown to work on an s390 GNU/Linux system that
2296 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2298 * Cygwin support for DWARF 2 added.
2300 * New native configurations
2302 GNU/Linux/hppa hppa*-*-linux*
2303 OpenBSD/hppa hppa*-*-openbsd*
2304 OpenBSD/m68k m68*-*-openbsd*
2305 OpenBSD/m88k m88*-*-openbsd*
2306 OpenBSD/powerpc powerpc-*-openbsd*
2307 NetBSD/vax vax-*-netbsd*
2308 OpenBSD/vax vax-*-openbsd*
2310 * END-OF-LIFE frame compatibility module
2312 GDB's internal frame infrastructure has been completely rewritten.
2313 The new infrastructure making it possible to support key new features
2314 including DWARF 2 Call Frame Information. To aid in the task of
2315 migrating old configurations to this new infrastructure, a
2316 compatibility module, that allowed old configurations to continue to
2317 work, was also included.
2319 GDB 6.2 will be the last release to include this frame compatibility
2320 module. This change directly impacts the following configurations:
2330 Unless there is activity to revive these configurations, they will be
2331 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2333 * REMOVED configurations and files
2335 Sun 3, running SunOS 3 m68*-*-sunos3*
2336 Sun 3, running SunOS 4 m68*-*-sunos4*
2337 Sun 2, running SunOS 3 m68000-*-sunos3*
2338 Sun 2, running SunOS 4 m68000-*-sunos4*
2339 Motorola 680x0 running LynxOS m68*-*-lynxos*
2340 AT&T 3b1/Unix pc m68*-att-*
2341 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2342 decstation mips-dec-* mips-little-*
2343 riscos mips-*-riscos* mips-*-sysv*
2344 sonymips mips-sony-*
2345 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2347 *** Changes in GDB 6.1.1:
2349 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2351 The TUI (Text-mode User Interface) is now built as part of a default
2352 GDB configuration. It is enabled by either selecting the TUI with the
2353 command line option "-i=tui" or by running the separate "gdbtui"
2354 program. For more information on the TUI, see the manual "Debugging
2357 * Pending breakpoint support (also included in GDB 6.1)
2359 Support has been added to allow you to specify breakpoints in shared
2360 libraries that have not yet been loaded. If a breakpoint location
2361 cannot be found, and the "breakpoint pending" option is set to auto,
2362 GDB queries you if you wish to make the breakpoint pending on a future
2363 shared-library load. If and when GDB resolves the breakpoint symbol,
2364 the pending breakpoint is removed as one or more regular breakpoints
2367 Pending breakpoints are very useful for GCJ Java debugging.
2369 * Fixed ISO-C build problems
2371 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2372 non ISO-C code that stopped them being built using a more strict ISO-C
2373 compiler (e.g., IBM's C compiler).
2375 * Fixed build problem on IRIX 5
2377 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2378 wasn't able to compile compile on an IRIX 5 system.
2380 * Added execute permission to gdb/gdbserver/configure
2382 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2383 permission. This bug would cause configure to fail on a number of
2384 systems (Solaris, IRIX). Ref: server/519.
2386 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2388 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2389 has been updated to use constant array sizes.
2391 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2393 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2394 its generated DWARF Call Frame Info. This encoding was causing GDB to
2395 panic, that panic has been fixed. Ref: gdb/1628.
2397 * Fixed a problem when examining parameters in shared library code.
2399 When examining parameters in optimized shared library code generated
2400 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2401 not available''. GDB now correctly displays the variable's value.
2403 *** Changes in GDB 6.1:
2405 * Removed --with-mmalloc
2407 Support for the mmalloc memory manager has been removed, as it
2408 conflicted with the internal gdb byte cache.
2410 * Changes in AMD64 configurations
2412 The AMD64 target now includes the %cs and %ss registers. As a result
2413 the AMD64 remote protocol has changed; this affects the floating-point
2414 and SSE registers. If you rely on those registers for your debugging,
2415 you should upgrade gdbserver on the remote side.
2417 * Revised SPARC target
2419 The SPARC target has been completely revised, incorporating the
2420 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2421 support for LynxOS and SunOS 4 has been dropped. Calling functions
2422 from within GDB on operating systems with a non-executable stack
2423 (Solaris, OpenBSD) now works.
2427 GDB has a new C++ demangler which does a better job on the mangled
2428 names generated by current versions of g++. It also runs faster, so
2429 with this and other changes gdb should now start faster on large C++
2432 * DWARF 2 Location Expressions
2434 GDB support for location expressions has been extended to support function
2435 arguments and frame bases. Older versions of GDB could crash when they
2438 * C++ nested types and namespaces
2440 GDB's support for nested types and namespaces in C++ has been
2441 improved, especially if you use the DWARF 2 debugging format. (This
2442 is the default for recent versions of GCC on most platforms.)
2443 Specifically, if you have a class "Inner" defined within a class or
2444 namespace "Outer", then GDB realizes that the class's name is
2445 "Outer::Inner", not simply "Inner". This should greatly reduce the
2446 frequency of complaints about not finding RTTI symbols. In addition,
2447 if you are stopped at inside of a function defined within a namespace,
2448 GDB modifies its name lookup accordingly.
2450 * New native configurations
2452 NetBSD/amd64 x86_64-*-netbsd*
2453 OpenBSD/amd64 x86_64-*-openbsd*
2454 OpenBSD/alpha alpha*-*-openbsd*
2455 OpenBSD/sparc sparc-*-openbsd*
2456 OpenBSD/sparc64 sparc64-*-openbsd*
2458 * New debugging protocols
2460 M32R with SDI protocol m32r-*-elf*
2462 * "set prompt-escape-char" command deleted.
2464 The command "set prompt-escape-char" has been deleted. This command,
2465 and its very obscure effet on GDB's prompt, was never documented,
2466 tested, nor mentioned in the NEWS file.
2468 * OBSOLETE configurations and files
2470 Configurations that have been declared obsolete in this release have
2471 been commented out. Unless there is activity to revive these
2472 configurations, the next release of GDB will have their sources
2473 permanently REMOVED.
2475 Sun 3, running SunOS 3 m68*-*-sunos3*
2476 Sun 3, running SunOS 4 m68*-*-sunos4*
2477 Sun 2, running SunOS 3 m68000-*-sunos3*
2478 Sun 2, running SunOS 4 m68000-*-sunos4*
2479 Motorola 680x0 running LynxOS m68*-*-lynxos*
2480 AT&T 3b1/Unix pc m68*-att-*
2481 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2482 decstation mips-dec-* mips-little-*
2483 riscos mips-*-riscos* mips-*-sysv*
2484 sonymips mips-sony-*
2485 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2487 * REMOVED configurations and files
2489 SGI Irix-4.x mips-sgi-irix4 or iris4
2490 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2491 Z8000 simulator z8k-zilog-none or z8ksim
2492 Matsushita MN10200 w/simulator mn10200-*-*
2493 H8/500 simulator h8500-hitachi-hms or h8500hms
2494 HP/PA running BSD hppa*-*-bsd*
2495 HP/PA running OSF/1 hppa*-*-osf*
2496 HP/PA Pro target hppa*-*-pro*
2497 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2498 386BSD i[3456]86-*-bsd*
2499 Sequent family i[3456]86-sequent-sysv4*
2500 i[3456]86-sequent-sysv*
2501 i[3456]86-sequent-bsd*
2502 SPARC running LynxOS sparc-*-lynxos*
2503 SPARC running SunOS 4 sparc-*-sunos4*
2504 Tsqware Sparclet sparclet-*-*
2505 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2507 *** Changes in GDB 6.0:
2511 Support for debugging the Objective-C programming language has been
2512 integrated into GDB.
2514 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2516 DWARF 2's Call Frame Information makes available compiler generated
2517 information that more exactly describes the program's run-time stack.
2518 By using this information, GDB is able to provide more robust stack
2521 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2522 have been updated to use a new backtrace mechanism which includes
2523 DWARF 2 CFI support.
2527 GDB's remote protocol has been extended to include support for hosted
2528 file I/O (where the remote target uses GDB's file system). See GDB's
2529 remote protocol documentation for details.
2531 * All targets using the new architecture framework.
2533 All of GDB's targets have been updated to use the new internal
2534 architecture framework. The way is now open for future GDB releases
2535 to include cross-architecture native debugging support (i386 on amd64,
2538 * GNU/Linux's Thread Local Storage (TLS)
2540 GDB now includes support for for the GNU/Linux implementation of
2541 per-thread variables.
2543 * GNU/Linux's Native POSIX Thread Library (NPTL)
2545 GDB's thread code has been updated to work with either the new
2546 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2548 * Separate debug info.
2550 GDB, in conjunction with BINUTILS, now supports a mechanism for
2551 automatically loading debug information from a separate file. Instead
2552 of shipping full debug and non-debug versions of system libraries,
2553 system integrators can now instead ship just the stripped libraries
2554 and optional debug files.
2556 * DWARF 2 Location Expressions
2558 DWARF 2 Location Expressions allow the compiler to more completely
2559 describe the location of variables (even in optimized code) to the
2562 GDB now includes preliminary support for location expressions (support
2563 for DW_OP_piece is still missing).
2567 A number of long standing bugs that caused GDB to die while starting a
2568 Java application have been fixed. GDB's Java support is now
2569 considered "useable".
2571 * GNU/Linux support for fork, vfork, and exec.
2573 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2574 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2577 * GDB supports logging output to a file
2579 There are two new commands, "set logging" and "show logging", which can be
2580 used to capture GDB's output to a file.
2582 * The meaning of "detach" has changed for gdbserver
2584 The "detach" command will now resume the application, as documented. To
2585 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2588 * d10v, m68hc11 `regs' command deprecated
2590 The `info registers' command has been updated so that it displays the
2591 registers using a format identical to the old `regs' command.
2595 A new command, "maint set profile on/off", has been added. This command can
2596 be used to enable or disable profiling while running GDB, to profile a
2597 session or a set of commands. In addition there is a new configure switch,
2598 "--enable-profiling", which will cause GDB to be compiled with profiling
2599 data, for more informative profiling results.
2601 * Default MI syntax changed to "mi2".
2603 The default MI (machine interface) syntax, enabled by the command line
2604 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2605 "mi1", can be enabled by specifying the option "-i=mi1".
2607 Support for the original "mi0" syntax (included in GDB 5.0) has been
2610 Fix for gdb/192: removed extraneous space when displaying frame level.
2611 Fix for gdb/672: update changelist is now output in mi list format.
2612 Fix for gdb/702: a -var-assign that updates the value now shows up
2613 in a subsequent -var-update.
2615 * New native configurations.
2617 FreeBSD/amd64 x86_64-*-freebsd*
2619 * Multi-arched targets.
2621 HP/PA HPUX11 hppa*-*-hpux*
2622 Renesas M32R/D w/simulator m32r-*-elf*
2624 * OBSOLETE configurations and files
2626 Configurations that have been declared obsolete in this release have
2627 been commented out. Unless there is activity to revive these
2628 configurations, the next release of GDB will have their sources
2629 permanently REMOVED.
2631 Z8000 simulator z8k-zilog-none or z8ksim
2632 Matsushita MN10200 w/simulator mn10200-*-*
2633 H8/500 simulator h8500-hitachi-hms or h8500hms
2634 HP/PA running BSD hppa*-*-bsd*
2635 HP/PA running OSF/1 hppa*-*-osf*
2636 HP/PA Pro target hppa*-*-pro*
2637 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2638 Sequent family i[3456]86-sequent-sysv4*
2639 i[3456]86-sequent-sysv*
2640 i[3456]86-sequent-bsd*
2641 Tsqware Sparclet sparclet-*-*
2642 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2644 * REMOVED configurations and files
2647 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2648 IBM AIX PS/2 i[3456]86-*-aix
2649 i386 running Mach 3.0 i[3456]86-*-mach3*
2650 i386 running Mach i[3456]86-*-mach*
2651 i386 running OSF/1 i[3456]86-*osf1mk*
2652 HP/Apollo 68k Family m68*-apollo*-sysv*,
2654 m68*-hp-bsd*, m68*-hp-hpux*
2655 Argonaut Risc Chip (ARC) arc-*-*
2656 Mitsubishi D30V d30v-*-*
2657 Fujitsu FR30 fr30-*-elf*
2658 OS/9000 i[34]86-*-os9k
2659 I960 with MON960 i960-*-coff
2661 * MIPS $fp behavior changed
2663 The convenience variable $fp, for the MIPS, now consistently returns
2664 the address of the current frame's base. Previously, depending on the
2665 context, $fp could refer to either $sp or the current frame's base
2666 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2667 The GNU Source-Level Debugger''.
2669 *** Changes in GDB 5.3:
2671 * GNU/Linux shared library multi-threaded performance improved.
2673 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2674 `/proc', in preference to `ptrace' for memory reads. This may result
2675 in an improvement in the start-up time of multi-threaded, shared
2676 library applications when run under GDB. One GDB user writes: ``loads
2677 shared libs like mad''.
2679 * ``gdbserver'' now supports multi-threaded applications on some targets
2681 Support for debugging multi-threaded applications which use
2682 the GNU/Linux LinuxThreads package has been added for
2683 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2684 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2686 * GDB now supports C/C++ preprocessor macros.
2688 GDB now expands preprocessor macro invocations in C/C++ expressions,
2689 and provides various commands for showing macro definitions and how
2692 The new command `macro expand EXPRESSION' expands any macro
2693 invocations in expression, and shows the result.
2695 The new command `show macro MACRO-NAME' shows the definition of the
2696 macro named MACRO-NAME, and where it was defined.
2698 Most compilers don't include information about macros in the debugging
2699 information by default. In GCC 3.1, for example, you need to compile
2700 your program with the options `-gdwarf-2 -g3'. If the macro
2701 information is present in the executable, GDB will read it.
2703 * Multi-arched targets.
2705 DEC Alpha (partial) alpha*-*-*
2706 DEC VAX (partial) vax-*-*
2708 National Semiconductor NS32000 (partial) ns32k-*-*
2709 Motorola 68000 (partial) m68k-*-*
2710 Motorola MCORE mcore-*-*
2714 Fujitsu FRV architecture added by Red Hat frv*-*-*
2717 * New native configurations
2719 Alpha NetBSD alpha*-*-netbsd*
2720 SH NetBSD sh*-*-netbsdelf*
2721 MIPS NetBSD mips*-*-netbsd*
2722 UltraSPARC NetBSD sparc64-*-netbsd*
2724 * OBSOLETE configurations and files
2726 Configurations that have been declared obsolete in this release have
2727 been commented out. Unless there is activity to revive these
2728 configurations, the next release of GDB will have their sources
2729 permanently REMOVED.
2731 Mitsubishi D30V d30v-*-*
2732 OS/9000 i[34]86-*-os9k
2733 IBM AIX PS/2 i[3456]86-*-aix
2734 Fujitsu FR30 fr30-*-elf*
2735 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2736 Argonaut Risc Chip (ARC) arc-*-*
2737 i386 running Mach 3.0 i[3456]86-*-mach3*
2738 i386 running Mach i[3456]86-*-mach*
2739 i386 running OSF/1 i[3456]86-*osf1mk*
2740 HP/Apollo 68k Family m68*-apollo*-sysv*,
2742 m68*-hp-bsd*, m68*-hp-hpux*
2743 I960 with MON960 i960-*-coff
2745 * OBSOLETE languages
2747 CHILL, a Pascal like language used by telecommunications companies.
2749 * REMOVED configurations and files
2751 AMD 29k family via UDI a29k-amd-udi, udi29k
2752 A29K VxWorks a29k-*-vxworks
2753 AMD 29000 embedded, using EBMON a29k-none-none
2754 AMD 29000 embedded with COFF a29k-none-coff
2755 AMD 29000 embedded with a.out a29k-none-aout
2757 testsuite/gdb.hp/gdb.threads-hp/ directory
2759 * New command "set max-user-call-depth <nnn>"
2761 This command allows the user to limit the call depth of user-defined
2762 commands. The default is 1024.
2764 * Changes in FreeBSD/i386 native debugging.
2766 Support for the "generate-core-file" has been added.
2768 * New commands "dump", "append", and "restore".
2770 These commands allow data to be copied from target memory
2771 to a bfd-format or binary file (dump and append), and back
2772 from a file into memory (restore).
2774 * Improved "next/step" support on multi-processor Alpha Tru64.
2776 The previous single-step mechanism could cause unpredictable problems,
2777 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2778 of a software single-step mechanism prevents this.
2780 *** Changes in GDB 5.2.1:
2788 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2789 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2790 Fix, by Joel Brobecker imported from mainline.
2792 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2793 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2794 Fix, by Fred Fish, imported from mainline.
2796 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2797 Surprisingly enough, it works now.
2798 By Michal Ludvig, imported from mainline.
2800 i386 hardware watchpoint support:
2801 avoid misses on second run for some targets.
2802 By Pierre Muller, imported from mainline.
2804 *** Changes in GDB 5.2:
2806 * New command "set trust-readonly-sections on[off]".
2808 This command is a hint that tells gdb that read-only sections
2809 really are read-only (ie. that their contents will not change).
2810 In this mode, gdb will go to the object file rather than the
2811 target to read memory from read-only sections (such as ".text").
2812 This can be a significant performance improvement on some
2813 (notably embedded) targets.
2815 * New command "generate-core-file" (or "gcore").
2817 This new gdb command allows the user to drop a core file of the child
2818 process state at any time. So far it's been implemented only for
2819 GNU/Linux and Solaris, but should be relatively easily ported to other
2820 hosts. Argument is core file name (defaults to core.<pid>).
2822 * New command line option
2824 GDB now accepts --pid or -p followed by a process id.
2826 * Change in command line behavior -- corefiles vs. process ids.
2828 There is a subtle behavior in the way in which GDB handles
2829 command line arguments. The first non-flag argument is always
2830 a program to debug, but the second non-flag argument may either
2831 be a corefile or a process id. Previously, GDB would attempt to
2832 open the second argument as a corefile, and if that failed, would
2833 issue a superfluous error message and then attempt to attach it as
2834 a process. Now, if the second argument begins with a non-digit,
2835 it will be treated as a corefile. If it begins with a digit,
2836 GDB will attempt to attach it as a process, and if no such process
2837 is found, will then attempt to open it as a corefile.
2839 * Changes in ARM configurations.
2841 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2842 configuration is fully multi-arch.
2844 * New native configurations
2846 ARM NetBSD arm*-*-netbsd*
2847 x86 OpenBSD i[3456]86-*-openbsd*
2848 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2849 Sparc64 running FreeBSD sparc64-*-freebsd*
2853 Sanyo XStormy16 xstormy16-elf
2855 * OBSOLETE configurations and files
2857 Configurations that have been declared obsolete in this release have
2858 been commented out. Unless there is activity to revive these
2859 configurations, the next release of GDB will have their sources
2860 permanently REMOVED.
2862 AMD 29k family via UDI a29k-amd-udi, udi29k
2863 A29K VxWorks a29k-*-vxworks
2864 AMD 29000 embedded, using EBMON a29k-none-none
2865 AMD 29000 embedded with COFF a29k-none-coff
2866 AMD 29000 embedded with a.out a29k-none-aout
2868 testsuite/gdb.hp/gdb.threads-hp/ directory
2870 * REMOVED configurations and files
2872 TI TMS320C80 tic80-*-*
2874 PowerPC Solaris powerpcle-*-solaris*
2875 PowerPC Windows NT powerpcle-*-cygwin32
2876 PowerPC Netware powerpc-*-netware*
2877 Harris/CXUX m88k m88*-harris-cxux*
2878 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2879 ns32k-utek-sysv* ns32k-utek-*
2880 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2881 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2882 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2883 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2884 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2886 * Changes to command line processing
2888 The new `--args' feature can be used to specify command-line arguments
2889 for the inferior from gdb's command line.
2891 * Changes to key bindings
2893 There is a new `operate-and-get-next' function bound to `C-o'.
2895 *** Changes in GDB 5.1.1
2897 Fix compile problem on DJGPP.
2899 Fix a problem with floating-point registers on the i386 being
2902 Fix to stop GDB crashing on .debug_str debug info.
2904 Numerous documentation fixes.
2906 Numerous testsuite fixes.
2908 *** Changes in GDB 5.1:
2910 * New native configurations
2912 Alpha FreeBSD alpha*-*-freebsd*
2913 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2914 MIPS GNU/Linux mips*-*-linux*
2915 MIPS SGI Irix 6.x mips*-sgi-irix6*
2916 ia64 AIX ia64-*-aix*
2917 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2921 Motorola 68HC11 and 68HC12 m68hc11-elf
2923 UltraSparc running GNU/Linux sparc64-*-linux*
2925 * OBSOLETE configurations and files
2927 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2928 Harris/CXUX m88k m88*-harris-cxux*
2929 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2930 ns32k-utek-sysv* ns32k-utek-*
2931 TI TMS320C80 tic80-*-*
2933 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2934 PowerPC Solaris powerpcle-*-solaris*
2935 PowerPC Windows NT powerpcle-*-cygwin32
2936 PowerPC Netware powerpc-*-netware*
2937 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2938 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2939 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2940 Apple Macintosh (MPW) host N/A
2942 stuff.c (Program to stuff files into a specially prepared space in kdb)
2943 kdb-start.c (Main loop for the standalone kernel debugger)
2945 Configurations that have been declared obsolete in this release have
2946 been commented out. Unless there is activity to revive these
2947 configurations, the next release of GDB will have their sources
2948 permanently REMOVED.
2950 * REMOVED configurations and files
2952 Altos 3068 m68*-altos-*
2953 Convex c1-*-*, c2-*-*
2955 ARM RISCix arm-*-* (as host)
2959 * GDB has been converted to ISO C.
2961 GDB's source code has been converted to ISO C. In particular, the
2962 sources are fully protoized, and rely on standard headers being
2967 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2969 * The MI enabled by default.
2971 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2972 revised and enabled by default. Packages which use GDB as a debugging
2973 engine behind a UI or another front end are encouraged to switch to
2974 using the GDB/MI interface, instead of the old annotations interface
2975 which is now deprecated.
2977 * Support for debugging Pascal programs.
2979 GDB now includes support for debugging Pascal programs. The following
2980 main features are supported:
2982 - Pascal-specific data types such as sets;
2984 - automatic recognition of Pascal sources based on file-name
2987 - Pascal-style display of data types, variables, and functions;
2989 - a Pascal expression parser.
2991 However, some important features are not yet supported.
2993 - Pascal string operations are not supported at all;
2995 - there are some problems with boolean types;
2997 - Pascal type hexadecimal constants are not supported
2998 because they conflict with the internal variables format;
3000 - support for Pascal objects and classes is not full yet;
3002 - unlike Pascal, GDB is case-sensitive for symbol names.
3004 * Changes in completion.
3006 Commands such as `shell', `run' and `set args', which pass arguments
3007 to inferior programs, now complete on file names, similar to what
3008 users expect at the shell prompt.
3010 Commands which accept locations, such as `disassemble', `print',
3011 `breakpoint', `until', etc. now complete on filenames as well as
3012 program symbols. Thus, if you type "break foob TAB", and the source
3013 files linked into the programs include `foobar.c', that file name will
3014 be one of the candidates for completion. However, file names are not
3015 considered for completion after you typed a colon that delimits a file
3016 name from a name of a function in that file, as in "break foo.c:bar".
3018 `set demangle-style' completes on available demangling styles.
3020 * New platform-independent commands:
3022 It is now possible to define a post-hook for a command as well as a
3023 hook that runs before the command. For more details, see the
3024 documentation of `hookpost' in the GDB manual.
3026 * Changes in GNU/Linux native debugging.
3028 Support for debugging multi-threaded programs has been completely
3029 revised for all platforms except m68k and sparc. You can now debug as
3030 many threads as your system allows you to have.
3032 Attach/detach is supported for multi-threaded programs.
3034 Support for SSE registers was added for x86. This doesn't work for
3035 multi-threaded programs though.
3037 * Changes in MIPS configurations.
3039 Multi-arch support is enabled for all MIPS configurations.
3041 GDB can now be built as native debugger on SGI Irix 6.x systems for
3042 debugging n32 executables. (Debugging 64-bit executables is not yet
3045 * Unified support for hardware watchpoints in all x86 configurations.
3047 Most (if not all) native x86 configurations support hardware-assisted
3048 breakpoints and watchpoints in a unified manner. This support
3049 implements debug register sharing between watchpoints, which allows to
3050 put a virtually infinite number of watchpoints on the same address,
3051 and also supports watching regions up to 16 bytes with several debug
3054 The new maintenance command `maintenance show-debug-regs' toggles
3055 debugging print-outs in functions that insert, remove, and test
3056 watchpoints and hardware breakpoints.
3058 * Changes in the DJGPP native configuration.
3060 New command ``info dos sysinfo'' displays assorted information about
3061 the CPU, OS, memory, and DPMI server.
3063 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3064 display information about segment descriptors stored in GDT, LDT, and
3067 New commands ``info dos pde'' and ``info dos pte'' display entries
3068 from Page Directory and Page Tables (for now works with CWSDPMI only).
3069 New command ``info dos address-pte'' displays the Page Table entry for
3070 a given linear address.
3072 GDB can now pass command lines longer than 126 characters to the
3073 program being debugged (requires an update to the libdbg.a library
3074 which is part of the DJGPP development kit).
3076 DWARF2 debug info is now supported.
3078 It is now possible to `step' and `next' through calls to `longjmp'.
3080 * Changes in documentation.
3082 All GDB documentation was converted to GFDL, the GNU Free
3083 Documentation License.
3085 Tracepoints-related commands are now fully documented in the GDB
3088 TUI, the Text-mode User Interface, is now documented in the manual.
3090 Tracepoints-related commands are now fully documented in the GDB
3093 The "GDB Internals" manual now has an index. It also includes
3094 documentation of `ui_out' functions, GDB coding standards, x86
3095 hardware watchpoints, and memory region attributes.
3097 * GDB's version number moved to ``version.in''
3099 The Makefile variable VERSION has been replaced by the file
3100 ``version.in''. People creating GDB distributions should update the
3101 contents of this file.
3105 GUD support is now a standard part of the EMACS distribution.
3107 *** Changes in GDB 5.0:
3109 * Improved support for debugging FP programs on x86 targets
3111 Unified and much-improved support for debugging floating-point
3112 programs on all x86 targets. In particular, ``info float'' now
3113 displays the FP registers in the same format on all x86 targets, with
3114 greater level of detail.
3116 * Improvements and bugfixes in hardware-assisted watchpoints
3118 It is now possible to watch array elements, struct members, and
3119 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3120 on x86 targets no longer erroneously trigger when the address is
3123 * Improvements in the native DJGPP version of GDB
3125 The distribution now includes all the scripts and auxiliary files
3126 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3127 machines ``out of the box''.
3129 The DJGPP version can now debug programs that use signals. It is
3130 possible to catch signals that happened in the debuggee, deliver
3131 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3132 would kill the program being debugged.) Programs that hook hardware
3133 interrupts (keyboard, timer, etc.) can also be debugged.
3135 It is now possible to debug DJGPP programs that redirect their
3136 standard handles or switch them to raw (as opposed to cooked) mode, or
3137 even close them. The command ``run < foo > bar'' works as expected,
3138 and ``info terminal'' reports useful information about the debuggee's
3139 terminal, including raw/cooked mode, redirection, etc.
3141 The DJGPP version now uses termios functions for console I/O, which
3142 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3145 DOS-style file names with drive letters are now fully supported by
3148 It is now possible to debug DJGPP programs that switch their working
3149 directory. It is also possible to rerun the debuggee any number of
3150 times without restarting GDB; thus, you can use the same setup,
3151 breakpoints, etc. for many debugging sessions.
3153 * New native configurations
3155 ARM GNU/Linux arm*-*-linux*
3156 PowerPC GNU/Linux powerpc-*-linux*
3160 Motorola MCore mcore-*-*
3161 x86 VxWorks i[3456]86-*-vxworks*
3162 PowerPC VxWorks powerpc-*-vxworks*
3163 TI TMS320C80 tic80-*-*
3165 * OBSOLETE configurations
3167 Altos 3068 m68*-altos-*
3168 Convex c1-*-*, c2-*-*
3170 ARM RISCix arm-*-* (as host)
3173 Configurations that have been declared obsolete will be commented out,
3174 but the code will be left in place. If there is no activity to revive
3175 these configurations before the next release of GDB, the sources will
3176 be permanently REMOVED.
3178 * Gould support removed
3180 Support for the Gould PowerNode and NP1 has been removed.
3182 * New features for SVR4
3184 On SVR4 native platforms (such as Solaris), if you attach to a process
3185 without first loading a symbol file, GDB will now attempt to locate and
3186 load symbols from the running process's executable file.
3188 * Many C++ enhancements
3190 C++ support has been greatly improved. Overload resolution now works properly
3191 in almost all cases. RTTI support is on the way.
3193 * Remote targets can connect to a sub-program
3195 A popen(3) style serial-device has been added. This device starts a
3196 sub-process (such as a stand-alone simulator) and then communicates
3197 with that. The sub-program to run is specified using the syntax
3198 ``|<program> <args>'' vis:
3200 (gdb) set remotedebug 1
3201 (gdb) target extended-remote |mn10300-elf-sim program-args
3203 * MIPS 64 remote protocol
3205 A long standing bug in the mips64 remote protocol where by GDB
3206 expected certain 32 bit registers (ex SR) to be transfered as 32
3207 instead of 64 bits has been fixed.
3209 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3210 added to provide backward compatibility with older versions of GDB.
3212 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3214 The command ``set remotebinarydownload'' command has been replaced by
3215 ``set remote X-packet''. Other commands in ``set remote'' family
3216 include ``set remote P-packet''.
3218 * Breakpoint commands accept ranges.
3220 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3221 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3222 ``tracepoint passcount'' also accepts a range of tracepoints.
3224 * ``apropos'' command added.
3226 The ``apropos'' command searches through command names and
3227 documentation strings, printing out matches, making it much easier to
3228 try to find a command that does what you are looking for.
3232 A new machine oriented interface (MI) has been added to GDB. This
3233 interface is designed for debug environments running GDB as a separate
3234 process. This is part of the long term libGDB project. See the
3235 "GDB/MI" chapter of the GDB manual for further information. It can be
3236 enabled by configuring with:
3238 .../configure --enable-gdbmi
3240 *** Changes in GDB-4.18:
3242 * New native configurations
3244 HP-UX 10.20 hppa*-*-hpux10.20
3245 HP-UX 11.x hppa*-*-hpux11.0*
3246 M68K GNU/Linux m68*-*-linux*
3250 Fujitsu FR30 fr30-*-elf*
3251 Intel StrongARM strongarm-*-*
3252 Mitsubishi D30V d30v-*-*
3254 * OBSOLETE configurations
3256 Gould PowerNode, NP1 np1-*-*, pn-*-*
3258 Configurations that have been declared obsolete will be commented out,
3259 but the code will be left in place. If there is no activity to revive
3260 these configurations before the next release of GDB, the sources will
3261 be permanently REMOVED.
3265 As a compatibility experiment, GDB's source files buildsym.h and
3266 buildsym.c have been converted to pure standard C, no longer
3267 containing any K&R compatibility code. We believe that all systems in
3268 use today either come with a standard C compiler, or have a GCC port
3269 available. If this is not true, please report the affected
3270 configuration to bug-gdb@gnu.org immediately. See the README file for
3271 information about getting a standard C compiler if you don't have one
3276 GDB now uses readline 2.2.
3278 * set extension-language
3280 You can now control the mapping between filename extensions and source
3281 languages by using the `set extension-language' command. For instance,
3282 you can ask GDB to treat .c files as C++ by saying
3283 set extension-language .c c++
3284 The command `info extensions' lists all of the recognized extensions
3285 and their associated languages.
3287 * Setting processor type for PowerPC and RS/6000
3289 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3290 you can use the `set processor' command to specify what variant of the
3291 PowerPC family you are debugging. The command
3295 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3296 following PowerPC and RS6000 variants:
3298 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3299 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3301 403GC IBM PowerPC 403GC
3302 505 Motorola PowerPC 505
3303 860 Motorola PowerPC 860 or 850
3304 601 Motorola PowerPC 601
3305 602 Motorola PowerPC 602
3306 603 Motorola/IBM PowerPC 603 or 603e
3307 604 Motorola PowerPC 604 or 604e
3308 750 Motorola/IBM PowerPC 750 or 750
3310 At the moment, this command just tells GDB what to name the
3311 special-purpose processor registers. Since almost all the affected
3312 registers are inaccessible to user-level programs, this command is
3313 only useful for remote debugging in its present form.
3317 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3318 more extensive support for HP-UX. Added features include shared
3319 library support, kernel threads and hardware watchpoints for 11.00,
3320 support for HP's ANSI C and C++ compilers, and a compatibility mode
3321 for xdb and dbx commands.
3325 HP's donation includes the new concept of catchpoints, which is a
3326 generalization of the old catch command. On HP-UX, it is now possible
3327 to catch exec, fork, and vfork, as well as library loading.
3329 This means that the existing catch command has changed; its first
3330 argument now specifies the type of catch to be set up. See the
3331 output of "help catch" for a list of catchpoint types.
3333 * Debugging across forks
3335 On HP-UX, you can choose which process to debug when a fork() happens
3340 HP has donated a curses-based terminal user interface (TUI). To get
3341 it, build with --enable-tui. Although this can be enabled for any
3342 configuration, at present it only works for native HP debugging.
3344 * GDB remote protocol additions
3346 A new protocol packet 'X' that writes binary data is now available.
3347 Default behavior is to try 'X', then drop back to 'M' if the stub
3348 fails to respond. The settable variable `remotebinarydownload'
3349 allows explicit control over the use of 'X'.
3351 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3352 full 64-bit address. The command
3354 set remoteaddresssize 32
3356 can be used to revert to the old behaviour. For existing remote stubs
3357 the change should not be noticed, as the additional address information
3360 In order to assist in debugging stubs, you may use the maintenance
3361 command `packet' to send any text string to the stub. For instance,
3363 maint packet heythere
3365 sends the packet "$heythere#<checksum>". Note that it is very easy to
3366 disrupt a debugging session by sending the wrong packet at the wrong
3369 The compare-sections command allows you to compare section data on the
3370 target to what is in the executable file without uploading or
3371 downloading, by comparing CRC checksums.
3373 * Tracing can collect general expressions
3375 You may now collect general expressions at tracepoints. This requires
3376 further additions to the target-side stub; see tracepoint.c and
3377 doc/agentexpr.texi for further details.
3379 * mask-address variable for Mips
3381 For Mips targets, you may control the zeroing of the upper 32 bits of
3382 a 64-bit address by entering `set mask-address on'. This is mainly
3383 of interest to users of embedded R4xxx and R5xxx processors.
3385 * Higher serial baud rates
3387 GDB's serial code now allows you to specify baud rates 57600, 115200,
3388 230400, and 460800 baud. (Note that your host system may not be able
3389 to achieve all of these rates.)
3393 The i960 configuration now includes an initial implementation of a
3394 builtin simulator, contributed by Jim Wilson.
3397 *** Changes in GDB-4.17:
3399 * New native configurations
3401 Alpha GNU/Linux alpha*-*-linux*
3402 Unixware 2.x i[3456]86-unixware2*
3403 Irix 6.x mips*-sgi-irix6*
3404 PowerPC GNU/Linux powerpc-*-linux*
3405 PowerPC Solaris powerpcle-*-solaris*
3406 Sparc GNU/Linux sparc-*-linux*
3407 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3411 Argonaut Risc Chip (ARC) arc-*-*
3412 Hitachi H8/300S h8300*-*-*
3413 Matsushita MN10200 w/simulator mn10200-*-*
3414 Matsushita MN10300 w/simulator mn10300-*-*
3415 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3416 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3417 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3418 Mitsubishi D10V w/simulator d10v-*-*
3419 Mitsubishi M32R/D w/simulator m32r-*-elf*
3420 Tsqware Sparclet sparclet-*-*
3421 NEC V850 w/simulator v850-*-*
3423 * New debugging protocols
3425 ARM with RDI protocol arm*-*-*
3426 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3427 DDB and LSI variants of PMON protocol mips*-*-*
3428 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3429 PowerPC with SDS protocol powerpc{,le}-*-eabi
3430 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3434 All configurations can now understand and use the DWARF 2 debugging
3435 format. The choice is automatic, if the symbol file contains DWARF 2
3440 GDB now includes basic Java language support. This support is
3441 only useful with Java compilers that produce native machine code.
3443 * solib-absolute-prefix and solib-search-path
3445 For SunOS and SVR4 shared libraries, you may now set the prefix for
3446 loading absolute shared library symbol files, and the search path for
3447 locating non-absolute shared library symbol files.
3449 * Live range splitting
3451 GDB can now effectively debug code for which GCC has performed live
3452 range splitting as part of its optimization. See gdb/doc/LRS for
3453 more details on the expected format of the stabs information.
3457 GDB's support for the GNU Hurd, including thread debugging, has been
3458 updated to work with current versions of the Hurd.
3462 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3463 instruction set. ARM GDB automatically detects when Thumb
3464 instructions are in use, and adjusts disassembly and backtracing
3469 GDB's MIPS target configurations now handle the MIP16 16-bit
3474 GDB now includes support for overlays; if an executable has been
3475 linked such that multiple sections are based at the same address, GDB
3476 will decide which section to use for symbolic info. You can choose to
3477 control the decision manually, using overlay commands, or implement
3478 additional target-side support and use "overlay load-target" to bring
3479 in the overlay mapping. Do "help overlay" for more detail.
3483 The command "info symbol <address>" displays information about
3484 the symbol at the specified address.
3488 The standard remote protocol now includes an extension that allows
3489 asynchronous collection and display of trace data. This requires
3490 extensive support in the target-side debugging stub. Tracing mode
3491 includes a new interaction mode in GDB and new commands: see the
3492 file tracepoint.c for more details.
3496 Configurations for embedded MIPS now include a simulator contributed
3497 by Cygnus Solutions. The simulator supports the instruction sets
3498 of most MIPS variants.
3502 Sparc configurations may now include the ERC32 simulator contributed
3503 by the European Space Agency. The simulator is not built into
3504 Sparc targets by default; configure with --enable-sim to include it.
3508 For target configurations that may include multiple variants of a
3509 basic architecture (such as MIPS and SH), you may now set the
3510 architecture explicitly. "set arch" sets, "info arch" lists
3511 the possible architectures.
3513 *** Changes in GDB-4.16:
3515 * New native configurations
3517 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3518 M68K NetBSD m68k-*-netbsd*
3519 PowerPC AIX 4.x powerpc-*-aix*
3520 PowerPC MacOS powerpc-*-macos*
3521 PowerPC Windows NT powerpcle-*-cygwin32
3522 RS/6000 AIX 4.x rs6000-*-aix4*
3526 ARM with RDP protocol arm-*-*
3527 I960 with MON960 i960-*-coff
3528 MIPS VxWorks mips*-*-vxworks*
3529 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3530 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3532 Matra Sparclet sparclet-*-*
3536 The powerpc-eabi configuration now includes the PSIM simulator,
3537 contributed by Andrew Cagney, with assistance from Mike Meissner.
3538 PSIM is a very elaborate model of the PowerPC, including not only
3539 basic instruction set execution, but also details of execution unit
3540 performance and I/O hardware. See sim/ppc/README for more details.
3544 GDB now works with Solaris 2.5.
3546 * Windows 95/NT native
3548 GDB will now work as a native debugger on Windows 95 and Windows NT.
3549 To build it from source, you must use the "gnu-win32" environment,
3550 which uses a DLL to emulate enough of Unix to run the GNU tools.
3551 Further information, binaries, and sources are available at
3552 ftp.cygnus.com, under pub/gnu-win32.
3554 * dont-repeat command
3556 If a user-defined command includes the command `dont-repeat', then the
3557 command will not be repeated if the user just types return. This is
3558 useful if the command is time-consuming to run, so that accidental
3559 extra keystrokes don't run the same command many times.
3561 * Send break instead of ^C
3563 The standard remote protocol now includes an option to send a break
3564 rather than a ^C to the target in order to interrupt it. By default,
3565 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3567 * Remote protocol timeout
3569 The standard remote protocol includes a new variable `remotetimeout'
3570 that allows you to set the number of seconds before GDB gives up trying
3571 to read from the target. The default value is 2.
3573 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3575 By default GDB will automatically keep track of objects as they are
3576 loaded and unloaded by the dynamic linker. By using the command `set
3577 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3578 when shared library events occur, thus allowing you to set breakpoints
3579 in shared libraries which are explicitly loaded by the inferior.
3581 Note this feature does not work on hpux8. On hpux9 you must link
3582 /usr/lib/end.o into your program. This feature should work
3583 automatically on hpux10.
3585 * Irix 5.x hardware watchpoint support
3587 Irix 5 configurations now support the use of hardware watchpoints.
3589 * Mips protocol "SYN garbage limit"
3591 When debugging a Mips target using the `target mips' protocol, you
3592 may set the number of characters that GDB will ignore by setting
3593 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3594 every character. The default value is 1050.
3596 * Recording and replaying remote debug sessions
3598 If you set `remotelogfile' to the name of a file, gdb will write to it
3599 a recording of a remote debug session. This recording may then be
3600 replayed back to gdb using "gdbreplay". See gdbserver/README for
3601 details. This is useful when you have a problem with GDB while doing
3602 remote debugging; you can make a recording of the session and send it
3603 to someone else, who can then recreate the problem.
3605 * Speedups for remote debugging
3607 GDB includes speedups for downloading and stepping MIPS systems using
3608 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3609 and more efficient S-record downloading.
3611 * Memory use reductions and statistics collection
3613 GDB now uses less memory and reports statistics about memory usage.
3614 Try the `maint print statistics' command, for example.
3616 *** Changes in GDB-4.15:
3618 * Psymtabs for XCOFF
3620 The symbol reader for AIX GDB now uses partial symbol tables. This
3621 can greatly improve startup time, especially for large executables.
3623 * Remote targets use caching
3625 Remote targets now use a data cache to speed up communication with the
3626 remote side. The data cache could lead to incorrect results because
3627 it doesn't know about volatile variables, thus making it impossible to
3628 debug targets which use memory mapped I/O devices. `set remotecache
3629 off' turns the the data cache off.
3631 * Remote targets may have threads
3633 The standard remote protocol now includes support for multiple threads
3634 in the target system, using new protocol commands 'H' and 'T'. See
3635 gdb/remote.c for details.
3639 If GDB is configured with `--enable-netrom', then it will include
3640 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3641 acts as though it is a bank of ROM on the target board, but you can
3642 write into it over the network. GDB's support consists only of
3643 support for fast loading into the emulated ROM; to debug, you must use
3644 another protocol, such as standard remote protocol. The usual
3645 sequence is something like
3647 target nrom <netrom-hostname>
3649 target remote <netrom-hostname>:1235
3653 GDB now includes support for the Apple Macintosh, as a host only. It
3654 may be run as either an MPW tool or as a standalone application, and
3655 it can debug through the serial port. All the usual GDB commands are
3656 available, but to the target command, you must supply "serial" as the
3657 device type instead of "/dev/ttyXX". See mpw-README in the main
3658 directory for more information on how to build. The MPW configuration
3659 scripts */mpw-config.in support only a few targets, and only the
3660 mips-idt-ecoff target has been tested.
3664 GDB configuration now uses autoconf. This is not user-visible,
3665 but does simplify configuration and building.
3669 GDB now supports hpux10.
3671 *** Changes in GDB-4.14:
3673 * New native configurations
3675 x86 FreeBSD i[345]86-*-freebsd
3676 x86 NetBSD i[345]86-*-netbsd
3677 NS32k NetBSD ns32k-*-netbsd
3678 Sparc NetBSD sparc-*-netbsd
3682 A29K VxWorks a29k-*-vxworks
3683 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3684 CPU32 EST-300 emulator m68*-*-est*
3685 PowerPC ELF powerpc-*-elf
3688 * Alpha OSF/1 support for procfs
3690 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3691 possible to attach to running processes. As the mounting of the /proc
3692 filesystem is optional on the Alpha, GDB automatically determines
3693 the availability of /proc during startup. This can lead to problems
3694 if /proc is unmounted after GDB has been started.
3696 * Arguments to user-defined commands
3698 User commands may accept up to 10 arguments separated by whitespace.
3699 Arguments are accessed within the user command via $arg0..$arg9. A
3702 print $arg0 + $arg1 + $arg2
3704 To execute the command use:
3707 Defines the command "adder" which prints the sum of its three arguments.
3708 Note the arguments are text substitutions, so they may reference variables,
3709 use complex expressions, or even perform inferior function calls.
3711 * New `if' and `while' commands
3713 This makes it possible to write more sophisticated user-defined
3714 commands. Both commands take a single argument, which is the
3715 expression to evaluate, and must be followed by the commands to
3716 execute, one per line, if the expression is nonzero, the list being
3717 terminated by the word `end'. The `if' command list may include an
3718 `else' word, which causes the following commands to be executed only
3719 if the expression is zero.
3721 * Fortran source language mode
3723 GDB now includes partial support for Fortran 77. It will recognize
3724 Fortran programs and can evaluate a subset of Fortran expressions, but
3725 variables and functions may not be handled correctly. GDB will work
3726 with G77, but does not yet know much about symbols emitted by other
3729 * Better HPUX support
3731 Most debugging facilities now work on dynamic executables for HPPAs
3732 running hpux9 or later. You can attach to running dynamically linked
3733 processes, but by default the dynamic libraries will be read-only, so
3734 for instance you won't be able to put breakpoints in them. To change
3735 that behavior do the following before running the program:
3741 This will cause the libraries to be mapped private and read-write.
3742 To revert to the normal behavior, do this:
3748 You cannot set breakpoints or examine data in the library until after
3749 the library is loaded if the function/data symbols do not have
3752 GDB can now also read debug symbols produced by the HP C compiler on
3753 HPPAs (sorry, no C++, Fortran or 68k support).
3755 * Target byte order now dynamically selectable
3757 You can choose which byte order to use with a target system, via the
3758 commands "set endian big" and "set endian little", and you can see the
3759 current setting by using "show endian". You can also give the command
3760 "set endian auto", in which case GDB will use the byte order
3761 associated with the executable. Currently, only embedded MIPS
3762 configurations support dynamic selection of target byte order.
3764 * New DOS host serial code
3766 This version uses DPMI interrupts to handle buffered I/O, so you
3767 no longer need to run asynctsr when debugging boards connected to
3770 *** Changes in GDB-4.13:
3772 * New "complete" command
3774 This lists all the possible completions for the rest of the line, if it
3775 were to be given as a command itself. This is intended for use by emacs.
3777 * Trailing space optional in prompt
3779 "set prompt" no longer adds a space for you after the prompt you set. This
3780 allows you to set a prompt which ends in a space or one that does not.
3782 * Breakpoint hit counts
3784 "info break" now displays a count of the number of times the breakpoint
3785 has been hit. This is especially useful in conjunction with "ignore"; you
3786 can ignore a large number of breakpoint hits, look at the breakpoint info
3787 to see how many times the breakpoint was hit, then run again, ignoring one
3788 less than that number, and this will get you quickly to the last hit of
3791 * Ability to stop printing at NULL character
3793 "set print null-stop" will cause GDB to stop printing the characters of
3794 an array when the first NULL is encountered. This is useful when large
3795 arrays actually contain only short strings.
3797 * Shared library breakpoints
3799 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3800 breakpoints in shared libraries before the executable is run.
3802 * Hardware watchpoints
3804 There is a new hardware breakpoint for the watch command for sparclite
3805 targets. See gdb/sparclite/hw_breakpoint.note.
3807 Hardware watchpoints are also now supported under GNU/Linux.
3811 Annotations have been added. These are for use with graphical interfaces,
3812 and are still experimental. Currently only gdba.el uses these.
3814 * Improved Irix 5 support
3816 GDB now works properly with Irix 5.2.
3818 * Improved HPPA support
3820 GDB now works properly with the latest GCC and GAS.
3822 * New native configurations
3824 Sequent PTX4 i[34]86-sequent-ptx4
3825 HPPA running OSF/1 hppa*-*-osf*
3826 Atari TT running SVR4 m68*-*-sysv4*
3827 RS/6000 LynxOS rs6000-*-lynxos*
3831 OS/9000 i[34]86-*-os9k
3832 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3835 * Hitachi SH7000 and E7000-PC ICE support
3837 There is now support for communicating with the Hitachi E7000-PC ICE.
3838 This is available automatically when GDB is configured for the SH.
3842 As usual, a variety of small fixes and improvements, both generic
3843 and configuration-specific. See the ChangeLog for more detail.
3845 *** Changes in GDB-4.12:
3847 * Irix 5 is now supported
3851 GDB-4.12 on the HPPA has a number of changes which make it unable
3852 to debug the output from the currently released versions of GCC and
3853 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3854 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3855 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3858 *** Changes in GDB-4.11:
3860 * User visible changes:
3864 The "set remotedebug" option is now consistent between the mips remote
3865 target, remote targets using the gdb-specific protocol, UDI (AMD's
3866 debug protocol for the 29k) and the 88k bug monitor. It is now an
3867 integer specifying a debug level (normally 0 or 1, but 2 means more
3868 debugging info for the mips target).
3870 * DEC Alpha native support
3872 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3873 debug info, but GDB works fairly well with the DEC compiler and should
3874 work with a future GCC release. See the README file for a few
3875 Alpha-specific notes.
3877 * Preliminary thread implementation
3879 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3881 * LynxOS native and target support for 386
3883 This release has been hosted on LynxOS 2.2, and also can be configured
3884 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3887 * Improvements in C++ mangling/demangling.
3889 This release has much better g++ debugging, specifically in name
3890 mangling/demangling, virtual function calls, print virtual table,
3891 call methods, ...etc.
3893 *** Changes in GDB-4.10:
3895 * User visible changes:
3897 Remote debugging using the GDB-specific (`target remote') protocol now
3898 supports the `load' command. This is only useful if you have some
3899 other way of getting the stub to the target system, and you can put it
3900 somewhere in memory where it won't get clobbered by the download.
3902 Filename completion now works.
3904 When run under emacs mode, the "info line" command now causes the
3905 arrow to point to the line specified. Also, "info line" prints
3906 addresses in symbolic form (as well as hex).
3908 All vxworks based targets now support a user settable option, called
3909 vxworks-timeout. This option represents the number of seconds gdb
3910 should wait for responses to rpc's. You might want to use this if
3911 your vxworks target is, perhaps, a slow software simulator or happens
3912 to be on the far side of a thin network line.
3916 This release contains support for using a DEC alpha as a GDB host for
3917 cross debugging. Native alpha debugging is not supported yet.
3920 *** Changes in GDB-4.9:
3924 This is the first GDB release which is accompanied by a matching testsuite.
3925 The testsuite requires installation of dejagnu, which should be available
3926 via ftp from most sites that carry GNU software.
3930 'Cfront' style demangling has had its name changed to 'ARM' style, to
3931 emphasize that it was written from the specifications in the C++ Annotated
3932 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3933 disclaimers, it still generated too much confusion with users attempting to
3934 use gdb with AT&T cfront.
3938 GDB now uses a standard remote interface to a simulator library.
3939 So far, the library contains simulators for the Zilog Z8001/2, the
3940 Hitachi H8/300, H8/500 and Super-H.
3942 * New targets supported
3944 H8/300 simulator h8300-hitachi-hms or h8300hms
3945 H8/500 simulator h8500-hitachi-hms or h8500hms
3946 SH simulator sh-hitachi-hms or sh
3947 Z8000 simulator z8k-zilog-none or z8ksim
3948 IDT MIPS board over serial line mips-idt-ecoff
3950 Cross-debugging to GO32 targets is supported. It requires a custom
3951 version of the i386-stub.c module which is integrated with the
3952 GO32 memory extender.
3954 * New remote protocols
3956 MIPS remote debugging protocol.
3958 * New source languages supported
3960 This version includes preliminary support for Chill, a Pascal like language
3961 used by telecommunications companies. Chill support is also being integrated
3962 into the GNU compiler, but we don't know when it will be publically available.
3965 *** Changes in GDB-4.8:
3967 * HP Precision Architecture supported
3969 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3970 version of this support was available as a set of patches from the
3971 University of Utah. GDB does not support debugging of programs
3972 compiled with the HP compiler, because HP will not document their file
3973 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3974 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3976 Many problems in the preliminary version have been fixed.
3978 * Faster and better demangling
3980 We have improved template demangling and fixed numerous bugs in the GNU style
3981 demangler. It can now handle type modifiers such as `static' or `const'. Wide
3982 character types (wchar_t) are now supported. Demangling of each symbol is now
3983 only done once, and is cached when the symbol table for a file is read in.
3984 This results in a small increase in memory usage for C programs, a moderate
3985 increase in memory usage for C++ programs, and a fantastic speedup in
3988 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
3989 from the specifications in the Annotated Reference Manual, which AT&T's
3990 compiler does not actually implement.
3992 * G++ multiple inheritance compiler problem
3994 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
3995 inheritance lattices was reworked to properly discover ambiguities. We
3996 recently found an example which causes this new algorithm to fail in a
3997 very subtle way, producing bad debug information for those classes.
3998 The file 'gcc.patch' (in this directory) can be applied to gcc to
3999 circumvent the problem. A future GCC release will contain a complete
4002 The previous G++ debug info problem (mentioned below for the gdb-4.7
4003 release) is fixed in gcc version 2.3.2.
4005 * Improved configure script
4007 The `configure' script will now attempt to guess your system type if
4008 you don't supply a host system type. The old scheme of supplying a
4009 host system triplet is preferable over using this. All the magic is
4010 done in the new `config.guess' script. Examine it for details.
4012 We have also brought our configure script much more in line with the FSF's
4013 version. It now supports the --with-xxx options. In particular,
4014 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4015 The resulting GDB will not be able to read arbitrary object file formats --
4016 only the format ``expected'' to be used on the configured target system.
4017 We hope to make this the default in a future release.
4019 * Documentation improvements
4021 There's new internal documentation on how to modify GDB, and how to
4022 produce clean changes to the code. We implore people to read it
4023 before submitting changes.
4025 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4026 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4027 `info' files are also provided. To build `info' files from scratch,
4028 you will need the latest `makeinfo' release, which will be available in
4029 a future texinfo-X.Y release.
4031 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4032 We're not sure exactly which versions have this problem, but it has
4033 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4034 or better. If that isn't possible, there is a patch in
4035 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4036 around this problem.
4040 GDB now supports array constants that can be used in expressions typed in by
4041 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4042 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4045 The new directory `gdb/sparclite' contains a program that demonstrates
4046 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4048 * New native hosts supported
4050 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4051 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4053 * New targets supported
4055 AMD 29k family via UDI a29k-amd-udi or udi29k
4057 * New file formats supported
4059 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4060 HPUX core files, and SCO 3.2v2 core files.
4064 Attaching to processes now works again; thanks for the many bug reports.
4066 We have also stomped on a bunch of core dumps caused by
4067 printf_filtered("%s") problems.
4069 We eliminated a copyright problem on the rpc and ptrace header files
4070 for VxWorks, which was discovered at the last minute during the 4.7
4071 release. You should now be able to build a VxWorks GDB.
4073 You can now interrupt gdb while an attached process is running. This
4074 will cause the attached process to stop, and give control back to GDB.
4076 We fixed problems caused by using too many file descriptors
4077 for reading symbols from object files and libraries. This was
4078 especially a problem for programs that used many (~100) shared
4081 The `step' command now only enters a subroutine if there is line number
4082 information for the subroutine. Otherwise it acts like the `next'
4083 command. Previously, `step' would enter subroutines if there was
4084 any debugging information about the routine. This avoids problems
4085 when using `cc -g1' on MIPS machines.
4087 * Internal improvements
4089 GDB's internal interfaces have been improved to make it easier to support
4090 debugging of multiple languages in the future.
4092 GDB now uses a common structure for symbol information internally.
4093 Minimal symbols (derived from linkage symbols in object files), partial
4094 symbols (from a quick scan of debug information), and full symbols
4095 contain a common subset of information, making it easier to write
4096 shared code that handles any of them.
4098 * New command line options
4100 We now accept --silent as an alias for --quiet.
4104 The memory-mapped-malloc library is now licensed under the GNU Library
4105 General Public License.
4107 *** Changes in GDB-4.7:
4109 * Host/native/target split
4111 GDB has had some major internal surgery to untangle the support for
4112 hosts and remote targets. Now, when you configure GDB for a remote
4113 target, it will no longer load in all of the support for debugging
4114 local programs on the host. When fully completed and tested, this will
4115 ensure that arbitrary host/target combinations are possible.
4117 The primary conceptual shift is to separate the non-portable code in
4118 GDB into three categories. Host specific code is required any time GDB
4119 is compiled on that host, regardless of the target. Target specific
4120 code relates to the peculiarities of the target, but can be compiled on
4121 any host. Native specific code is everything else: it can only be
4122 built when the host and target are the same system. Child process
4123 handling and core file support are two common `native' examples.
4125 GDB's use of /proc for controlling Unix child processes is now cleaner.
4126 It has been split out into a single module under the `target_ops' vector,
4127 plus two native-dependent functions for each system that uses /proc.
4129 * New hosts supported
4131 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4132 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4133 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4135 * New targets supported
4137 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4138 68030 and CPU32 m68030-*-*, m68332-*-*
4140 * New native hosts supported
4142 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4143 (386bsd is not well tested yet)
4144 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4146 * New file formats supported
4148 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4149 supports reading of `a.out.adobe' object files, which are an a.out
4150 format extended with minimal information about multiple sections.
4154 `show copying' is the same as the old `info copying'.
4155 `show warranty' is the same as `info warrantee'.
4156 These were renamed for consistency. The old commands continue to work.
4158 `info handle' is a new alias for `info signals'.
4160 You can now define pre-command hooks, which attach arbitrary command
4161 scripts to any command. The commands in the hook will be executed
4162 prior to the user's command. You can also create a hook which will be
4163 executed whenever the program stops. See gdb.texinfo.
4167 We now deal with Cfront style name mangling, and can even extract type
4168 info from mangled symbols. GDB can automatically figure out which
4169 symbol mangling style your C++ compiler uses.
4171 Calling of methods and virtual functions has been improved as well.
4175 The crash that occured when debugging Sun Ansi-C compiled binaries is
4176 fixed. This was due to mishandling of the extra N_SO stabs output
4179 We also finally got Ultrix 4.2 running in house, and fixed core file
4180 support, with help from a dozen people on the net.
4182 John M. Farrell discovered that the reason that single-stepping was so
4183 slow on all of the Mips based platforms (primarily SGI and DEC) was
4184 that we were trying to demangle and lookup a symbol used for internal
4185 purposes on every instruction that was being stepped through. Changing
4186 the name of that symbol so that it couldn't be mistaken for a C++
4187 mangled symbol sped things up a great deal.
4189 Rich Pixley sped up symbol lookups in general by getting much smarter
4190 about when C++ symbol mangling is necessary. This should make symbol
4191 completion (TAB on the command line) much faster. It's not as fast as
4192 we'd like, but it's significantly faster than gdb-4.6.
4196 A new user controllable variable 'call_scratch_address' can
4197 specify the location of a scratch area to be used when GDB
4198 calls a function in the target. This is necessary because the
4199 usual method of putting the scratch area on the stack does not work
4200 in systems that have separate instruction and data spaces.
4202 We integrated changes to support the 29k UDI (Universal Debugger
4203 Interface), but discovered at the last minute that we didn't have all
4204 of the appropriate copyright paperwork. We are working with AMD to
4205 resolve this, and hope to have it available soon.
4209 We have sped up the remote serial line protocol, especially for targets
4210 with lots of registers. It now supports a new `expedited status' ('T')
4211 message which can be used in place of the existing 'S' status message.
4212 This allows the remote stub to send only the registers that GDB
4213 needs to make a quick decision about single-stepping or conditional
4214 breakpoints, eliminating the need to fetch the entire register set for
4215 each instruction being stepped through.
4217 The GDB remote serial protocol now implements a write-through cache for
4218 registers, only re-reading the registers if the target has run.
4220 There is also a new remote serial stub for SPARC processors. You can
4221 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4222 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4223 processor with a serial port.
4227 Configure.in files have become much easier to read and modify. A new
4228 `table driven' format makes it more obvious what configurations are
4229 supported, and what files each one uses.
4233 There is a new opcodes library which will eventually contain all of the
4234 disassembly routines and opcode tables. At present, it only contains
4235 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4236 disassembler (binutils/objdump) to share these routines.
4238 The libiberty library is now copylefted under the GNU Library General
4239 Public License. This allows more liberal use, and was done so libg++
4240 can use it. This makes no difference to GDB, since the Library License
4241 grants all the rights from the General Public License.
4245 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4246 reference to the stabs symbol info used by the debugger. It is (as far
4247 as we know) the only published document on this fascinating topic. We
4248 encourage you to read it, compare it to the stabs information on your
4249 system, and send improvements on the document in general (to
4250 bug-gdb@prep.ai.mit.edu).
4252 And, of course, many bugs have been fixed.
4255 *** Changes in GDB-4.6:
4257 * Better support for C++ function names
4259 GDB now accepts as input the "demangled form" of C++ overloaded function
4260 names and member function names, and can do command completion on such names
4261 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4262 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4263 Make use of command completion, it is your friend.
4265 GDB also now accepts a variety of C++ mangled symbol formats. They are
4266 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4267 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4268 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4269 for the list of formats.
4271 * G++ symbol mangling problem
4273 Recent versions of gcc have a bug in how they emit debugging information for
4274 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4275 directory) can be applied to gcc to fix the problem. Alternatively, if you
4276 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4277 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4278 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4281 * New 'maintenance' command
4283 All of the commands related to hacking GDB internals have been moved out of
4284 the main command set, and now live behind the 'maintenance' command. This
4285 can also be abbreviated as 'mt'. The following changes were made:
4287 dump-me -> maintenance dump-me
4288 info all-breakpoints -> maintenance info breakpoints
4289 printmsyms -> maintenance print msyms
4290 printobjfiles -> maintenance print objfiles
4291 printpsyms -> maintenance print psymbols
4292 printsyms -> maintenance print symbols
4294 The following commands are new:
4296 maintenance demangle Call internal GDB demangler routine to
4297 demangle a C++ link name and prints the result.
4298 maintenance print type Print a type chain for a given symbol
4300 * Change to .gdbinit file processing
4302 We now read the $HOME/.gdbinit file before processing the argv arguments
4303 (e.g. reading symbol files or core files). This allows global parameters to
4304 be set, which will apply during the symbol reading. The ./.gdbinit is still
4305 read after argv processing.
4307 * New hosts supported
4309 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4311 GNU/Linux support i386-unknown-linux or linux
4313 We are also including code to support the HP/PA running BSD and HPUX. This
4314 is almost guaranteed not to work, as we didn't have time to test or build it
4315 for this release. We are including it so that the more adventurous (or
4316 masochistic) of you can play with it. We also had major problems with the
4317 fact that the compiler that we got from HP doesn't support the -g option.
4320 * New targets supported
4322 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4324 * More smarts about finding #include files
4326 GDB now remembers the compilation directory for all include files, and for
4327 all files from which C is generated (like yacc and lex sources). This
4328 greatly improves GDB's ability to find yacc/lex sources, and include files,
4329 especially if you are debugging your program from a directory different from
4330 the one that contains your sources.
4332 We also fixed a bug which caused difficulty with listing and setting
4333 breakpoints in include files which contain C code. (In the past, you had to
4334 try twice in order to list an include file that you hadn't looked at before.)
4336 * Interesting infernals change
4338 GDB now deals with arbitrary numbers of sections, where the symbols for each
4339 section must be relocated relative to that section's landing place in the
4340 target's address space. This work was needed to support ELF with embedded
4341 stabs used by Solaris-2.0.
4343 * Bug fixes (of course!)
4345 There have been loads of fixes for the following things:
4346 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4347 i960, stabs, DOS(GO32), procfs, etc...
4349 See the ChangeLog for details.
4351 *** Changes in GDB-4.5:
4353 * New machines supported (host and target)
4355 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4357 SGI Irix-4.x mips-sgi-irix4 or iris4
4359 * New malloc package
4361 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4362 Mmalloc is capable of handling mutiple heaps of memory. It is also
4363 capable of saving a heap to a file, and then mapping it back in later.
4364 This can be used to greatly speedup the startup of GDB by using a
4365 pre-parsed symbol table which lives in a mmalloc managed heap. For
4366 more details, please read mmalloc/mmalloc.texi.
4370 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4371 'help info proc' for details.
4373 * MIPS ecoff symbol table format
4375 The code that reads MIPS symbol table format is now supported on all hosts.
4376 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4379 * File name changes for MS-DOS
4381 Many files in the config directories have been renamed to make it easier to
4382 support GDB on MS-DOSe systems (which have very restrictive file name
4383 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4384 environment) is close to working but has some remaining problems. Note
4385 that debugging of DOS programs is not supported, due to limitations
4386 in the ``operating system'', but it can be used to host cross-debugging.
4388 * Cross byte order fixes
4390 Many fixes have been made to support cross debugging of Sparc and MIPS
4391 targets from hosts whose byte order differs.
4393 * New -mapped and -readnow options
4395 If memory-mapped files are available on your system through the 'mmap'
4396 system call, you can use the -mapped option on the `file' or
4397 `symbol-file' commands to cause GDB to write the symbols from your
4398 program into a reusable file. If the program you are debugging is
4399 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4400 Future GDB debugging sessions will notice the presence of this file,
4401 and will quickly map in symbol information from it, rather than reading
4402 the symbol table from the executable program. Using the '-mapped'
4403 option in a GDB `file' or `symbol-file' command has the same effect as
4404 starting GDB with the '-mapped' command-line option.
4406 You can cause GDB to read the entire symbol table immediately by using
4407 the '-readnow' option with any of the commands that load symbol table
4408 information (or on the GDB command line). This makes the command
4409 slower, but makes future operations faster.
4411 The -mapped and -readnow options are typically combined in order to
4412 build a `fred.syms' file that contains complete symbol information.
4413 A simple GDB invocation to do nothing but build a `.syms' file for future
4416 gdb -batch -nx -mapped -readnow programname
4418 The `.syms' file is specific to the host machine on which GDB is run.
4419 It holds an exact image of GDB's internal symbol table. It cannot be
4420 shared across multiple host platforms.
4422 * longjmp() handling
4424 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4425 siglongjmp() without losing control. This feature has not yet been ported to
4426 all systems. It currently works on many 386 platforms, all MIPS-based
4427 platforms (SGI, DECstation, etc), and Sun3/4.
4431 Preliminary work has been put in to support the new Solaris OS from Sun. At
4432 this time, it can control and debug processes, but it is not capable of
4437 As always, many many bug fixes. The major areas were with g++, and mipsread.
4438 People using the MIPS-based platforms should experience fewer mysterious
4439 crashes and trashed symbol tables.
4441 *** Changes in GDB-4.4:
4443 * New machines supported (host and target)
4445 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4447 BSD Reno on Vax vax-dec-bsd
4448 Ultrix on Vax vax-dec-ultrix
4450 * New machines supported (target)
4452 AMD 29000 embedded, using EBMON a29k-none-none
4456 GDB continues to improve its handling of C++. `References' work better.
4457 The demangler has also been improved, and now deals with symbols mangled as
4458 per the Annotated C++ Reference Guide.
4460 GDB also now handles `stabs' symbol information embedded in MIPS
4461 `ecoff' symbol tables. Since the ecoff format was not easily
4462 extensible to handle new languages such as C++, this appeared to be a
4463 good way to put C++ debugging info into MIPS binaries. This option
4464 will be supported in the GNU C compiler, version 2, when it is
4467 * New features for SVR4
4469 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4470 shared libraries. Debugging dynamically linked programs should present
4471 only minor differences from debugging statically linked programs.
4473 The `info proc' command will print out information about any process
4474 on an SVR4 system (including the one you are debugging). At the moment,
4475 it prints the address mappings of the process.
4477 If you bring up GDB on another SVR4 system, please send mail to
4478 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4480 * Better dynamic linking support in SunOS
4482 Reading symbols from shared libraries which contain debugging symbols
4483 now works properly. However, there remain issues such as automatic
4484 skipping of `transfer vector' code during function calls, which
4485 make it harder to debug code in a shared library, than to debug the
4486 same code linked statically.
4490 GDB is now using the latest `getopt' routines from the FSF. This
4491 version accepts the -- prefix for options with long names. GDB will
4492 continue to accept the old forms (-option and +option) as well.
4493 Various single letter abbreviations for options have been explicity
4494 added to the option table so that they won't get overshadowed in the
4495 future by other options that begin with the same letter.
4499 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4500 Many assorted bugs have been handled. Many more remain to be handled.
4501 See the various ChangeLog files (primarily in gdb and bfd) for details.
4504 *** Changes in GDB-4.3:
4506 * New machines supported (host and target)
4508 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4509 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4510 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4512 * Almost SCO Unix support
4514 We had hoped to support:
4515 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4516 (except for core file support), but we discovered very late in the release
4517 that it has problems with process groups that render gdb unusable. Sorry
4518 about that. I encourage people to fix it and post the fixes.
4520 * Preliminary ELF and DWARF support
4522 GDB can read ELF object files on System V Release 4, and can handle
4523 debugging records for C, in DWARF format, in ELF files. This support
4524 is preliminary. If you bring up GDB on another SVR4 system, please
4525 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4530 GDB now uses the latest `readline' library. One user-visible change
4531 is that two tabs will list possible command completions, which previously
4532 required typing M-? (meta-question mark, or ESC ?).
4536 The `stepi' bug that many of you noticed has been squashed.
4537 Many bugs in C++ have been handled. Many more remain to be handled.
4538 See the various ChangeLog files (primarily in gdb and bfd) for details.
4540 * State of the MIPS world (in case you wondered):
4542 GDB can understand the symbol tables emitted by the compilers
4543 supplied by most vendors of MIPS-based machines, including DEC. These
4544 symbol tables are in a format that essentially nobody else uses.
4546 Some versions of gcc come with an assembler post-processor called
4547 mips-tfile. This program is required if you want to do source-level
4548 debugging of gcc-compiled programs. I believe FSF does not ship
4549 mips-tfile with gcc version 1, but it will eventually come with gcc
4552 Debugging of g++ output remains a problem. g++ version 1.xx does not
4553 really support it at all. (If you're lucky, you should be able to get
4554 line numbers and stack traces to work, but no parameters or local
4555 variables.) With some work it should be possible to improve the
4558 When gcc version 2 is released, you will have somewhat better luck.
4559 However, even then you will get confusing results for inheritance and
4562 We will eventually provide full debugging of g++ output on
4563 DECstations. This will probably involve some kind of stabs-in-ecoff
4564 encapulation, but the details have not been worked out yet.
4567 *** Changes in GDB-4.2:
4569 * Improved configuration
4571 Only one copy of `configure' exists now, and it is not self-modifying.
4572 Porting BFD is simpler.
4576 The `step' and `next' commands now only stop at the first instruction
4577 of a source line. This prevents the multiple stops that used to occur
4578 in switch statements, for-loops, etc. `Step' continues to stop if a
4579 function that has debugging information is called within the line.
4583 Lots of small bugs fixed. More remain.
4585 * New host supported (not target)
4587 Intel 386 PC clone running Mach i386-none-mach
4590 *** Changes in GDB-4.1:
4592 * Multiple source language support
4594 GDB now has internal scaffolding to handle several source languages.
4595 It determines the type of each source file from its filename extension,
4596 and will switch expression parsing and number formatting to match the
4597 language of the function in the currently selected stack frame.
4598 You can also specifically set the language to be used, with
4599 `set language c' or `set language modula-2'.
4603 GDB now has preliminary support for the GNU Modula-2 compiler,
4604 currently under development at the State University of New York at
4605 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4606 continue through the fall of 1991 and into 1992.
4608 Other Modula-2 compilers are currently not supported, and attempting to
4609 debug programs compiled with them will likely result in an error as the
4610 symbol table is read. Feel free to work on it, though!
4612 There are hooks in GDB for strict type checking and range checking,
4613 in the `Modula-2 philosophy', but they do not currently work.
4617 GDB can now write to executable and core files (e.g. patch
4618 a variable's value). You must turn this switch on, specify
4619 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4620 by assigning a new value to a variable. Modifications take
4623 * Automatic SunOS shared library reading
4625 When you run your program, GDB automatically determines where its
4626 shared libraries (if any) have been loaded, and reads their symbols.
4627 The `share' command is no longer needed. This also works when
4628 examining core files.
4632 You can specify the number of lines that the `list' command shows.
4635 * New machines supported (host and target)
4637 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4638 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4639 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4641 * New hosts supported (not targets)
4643 IBM RT/PC: romp-ibm-aix or rtpc
4645 * New targets supported (not hosts)
4647 AMD 29000 embedded with COFF a29k-none-coff
4648 AMD 29000 embedded with a.out a29k-none-aout
4649 Ultracomputer remote kernel debug a29k-nyu-kern
4651 * New remote interfaces
4657 *** Changes in GDB-4.0:
4661 Wide output is wrapped at good places to make the output more readable.
4663 Gdb now supports cross-debugging from a host machine of one type to a
4664 target machine of another type. Communication with the target system
4665 is over serial lines. The ``target'' command handles connecting to the
4666 remote system; the ``load'' command will download a program into the
4667 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4668 also supports debugging of realtime processes running under VxWorks,
4669 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4670 stub on the target system.
4672 New CPUs supported include the AMD 29000 and Intel 960.
4674 GDB now reads object files and symbol tables via a ``binary file''
4675 library, which allows a single copy of GDB to debug programs of multiple
4676 object file types such as a.out and coff.
4678 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4679 refcard.dvi and refcard.ps are available to format it).
4682 * Control-Variable user interface simplified
4684 All variables that control the operation of the debugger can be set
4685 by the ``set'' command, and displayed by the ``show'' command.
4687 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4688 ``Show prompt'' produces the response:
4689 Gdb's prompt is new-gdb=>.
4691 What follows are the NEW set commands. The command ``help set'' will
4692 print a complete list of old and new set commands. ``help set FOO''
4693 will give a longer description of the variable FOO. ``show'' will show
4694 all of the variable descriptions and their current settings.
4696 confirm on/off: Enables warning questions for operations that are
4697 hard to recover from, e.g. rerunning the program while
4698 it is already running. Default is ON.
4700 editing on/off: Enables EMACS style command line editing
4701 of input. Previous lines can be recalled with
4702 control-P, the current line can be edited with control-B,
4703 you can search for commands with control-R, etc.
4706 history filename NAME: NAME is where the gdb command history
4707 will be stored. The default is .gdb_history,
4708 or the value of the environment variable
4711 history size N: The size, in commands, of the command history. The
4712 default is 256, or the value of the environment variable
4715 history save on/off: If this value is set to ON, the history file will
4716 be saved after exiting gdb. If set to OFF, the
4717 file will not be saved. The default is OFF.
4719 history expansion on/off: If this value is set to ON, then csh-like
4720 history expansion will be performed on
4721 command line input. The default is OFF.
4723 radix N: Sets the default radix for input and output. It can be set
4724 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4725 in the current radix, so "set radix 10" is always a no-op.
4727 height N: This integer value is the number of lines on a page. Default
4728 is 24, the current `stty rows'' setting, or the ``li#''
4729 setting from the termcap entry matching the environment
4732 width N: This integer value is the number of characters on a line.
4733 Default is 80, the current `stty cols'' setting, or the ``co#''
4734 setting from the termcap entry matching the environment
4737 Note: ``set screensize'' is obsolete. Use ``set height'' and
4738 ``set width'' instead.
4740 print address on/off: Print memory addresses in various command displays,
4741 such as stack traces and structure values. Gdb looks
4742 more ``symbolic'' if you turn this off; it looks more
4743 ``machine level'' with it on. Default is ON.
4745 print array on/off: Prettyprint arrays. New convenient format! Default
4748 print demangle on/off: Print C++ symbols in "source" form if on,
4751 print asm-demangle on/off: Same, for assembler level printouts
4754 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4757 * Support for Epoch Environment.
4759 The epoch environment is a version of Emacs v18 with windowing. One
4760 new command, ``inspect'', is identical to ``print'', except that if you
4761 are running in the epoch environment, the value is printed in its own
4765 * Support for Shared Libraries
4767 GDB can now debug programs and core files that use SunOS shared libraries.
4768 Symbols from a shared library cannot be referenced
4769 before the shared library has been linked with the program (this
4770 happens after you type ``run'' and before the function main() is entered).
4771 At any time after this linking (including when examining core files
4772 from dynamically linked programs), gdb reads the symbols from each
4773 shared library when you type the ``sharedlibrary'' command.
4774 It can be abbreviated ``share''.
4776 sharedlibrary REGEXP: Load shared object library symbols for files
4777 matching a unix regular expression. No argument
4778 indicates to load symbols for all shared libraries.
4780 info sharedlibrary: Status of loaded shared libraries.
4785 A watchpoint stops execution of a program whenever the value of an
4786 expression changes. Checking for this slows down execution
4787 tremendously whenever you are in the scope of the expression, but is
4788 quite useful for catching tough ``bit-spreader'' or pointer misuse
4789 problems. Some machines such as the 386 have hardware for doing this
4790 more quickly, and future versions of gdb will use this hardware.
4792 watch EXP: Set a watchpoint (breakpoint) for an expression.
4794 info watchpoints: Information about your watchpoints.
4796 delete N: Deletes watchpoint number N (same as breakpoints).
4797 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4798 enable N: Re-enables watchpoint number N (same as breakpoints).
4801 * C++ multiple inheritance
4803 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4806 * C++ exception handling
4808 Gdb now supports limited C++ exception handling. Besides the existing
4809 ability to breakpoint on an exception handler, gdb can breakpoint on
4810 the raising of an exception (before the stack is peeled back to the
4813 catch FOO: If there is a FOO exception handler in the dynamic scope,
4814 set a breakpoint to catch exceptions which may be raised there.
4815 Multiple exceptions (``catch foo bar baz'') may be caught.
4817 info catch: Lists all exceptions which may be caught in the
4818 current stack frame.
4821 * Minor command changes
4823 The command ``call func (arg, arg, ...)'' now acts like the print
4824 command, except it does not print or save a value if the function's result
4825 is void. This is similar to dbx usage.
4827 The ``up'' and ``down'' commands now always print the frame they end up
4828 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4829 frames without printing.
4831 * New directory command
4833 'dir' now adds directories to the FRONT of the source search path.
4834 The path starts off empty. Source files that contain debug information
4835 about the directory in which they were compiled can be found even
4836 with an empty path; Sun CC and GCC include this information. If GDB can't
4837 find your source file in the current directory, type "dir .".
4839 * Configuring GDB for compilation
4841 For normal use, type ``./configure host''. See README or gdb.texinfo
4844 GDB now handles cross debugging. If you are remotely debugging between
4845 two different machines, type ``./configure host -target=targ''.
4846 Host is the machine where GDB will run; targ is the machine
4847 where the program that you are debugging will run.