1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
8 ** GDB commands implemented in Python can now be put in command class
11 ** The "maint set python print-stack on|off" is now deleted.
13 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
14 apply "flag enum"-style pretty-printing to any enum.
16 ** gdb.lookup_symbol can now work when there is no current frame.
18 ** gdb.Symbol now has a 'line' attribute, holding the line number in
19 the source at which the symbol was defined.
21 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
22 method 'value'. The former indicates whether the symbol needs a
23 frame in order to compute its value, and the latter computes the
26 * GDBserver now supports stdio connections.
27 E.g. (gdb) target remote | ssh myhost gdbserver - hello
29 * The binary "gdbtui" can no longer be built or installed.
30 Use "gdb -tui" instead.
32 * GDB will now print "flag" enums specially. A flag enum is one where
33 all the enumerator values have no bits in common when pairwise
34 "and"ed. When printing a value whose type is a flag enum, GDB will
35 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
36 (gdb) print (enum E) 3
39 * The filename part of a linespec will now match trailing components
40 of a source file name. For example, "break gcc/expr.c:1000" will
41 now set a breakpoint in build/gcc/expr.c, but not
44 * The "info proc" and "generate-core-file" commands will now also
45 work on remote targets connected to GDBserver on Linux.
47 * The command "info catch" has been removed. It has been disabled
50 * The "catch exception" and "catch assert" commands now accept
51 a condition at the end of the command, much like the "break"
52 command does. For instance:
54 (gdb) catch exception Constraint_Error if Barrier = True
56 Previously, it was possible to add a condition to such catchpoints,
57 but it had to be done as a second step, after the catchpoint had been
58 created, using the "condition" command.
60 * The "info static-tracepoint-marker" command will now also work on
61 native Linux targets with in-process agent.
65 ** "catch load" and "catch unload" can be used to stop when a shared
66 library is loaded or unloaded, respectively.
68 ** "enable count" can be used to auto-disable a breakpoint after
73 Renesas RL78 rl78-*-elf
74 HP OpenVMS ia64 ia64-hp-openvms*
76 * GDBserver supports evaluation of breakpoint conditions. When
77 support is advertised by GDBserver, GDB may be told to send the
78 breakpoint conditions in bytecode form to GDBserver. GDBserver
79 will only report the breakpoint trigger to GDB when its condition
84 set breakpoint condition-evaluation
85 show breakpoint condition-evaluation
86 Controls whether breakpoint conditions are evaluated by GDB ("gdb") or by
88 This option can improve debugger efficiency depending on the speed of the
93 z0/z1 conditional breakpoints extension
95 The z0/z1 breakpoint insertion packets have been extended to carry
96 a list of conditional expressions over to the remote stub depending on the
97 condition evaluation mode. The use of this extension can be controlled
98 via the "set remote conditional-breakpoints-packet" command.
100 *** Changes in GDB 7.4
102 * GDB now handles ambiguous linespecs more consistently; the existing
103 FILE:LINE support has been expanded to other types of linespecs. A
104 breakpoint will now be set on all matching locations in all
105 inferiors, and locations will be added or removed according to
108 * GDB now allows you to skip uninteresting functions and files when
109 stepping with the "skip function" and "skip file" commands.
111 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
112 and "show remote hardware-watchpoint-length-limit". These allows to
113 set or show the maximum length limit (in bytes) of a remote
114 target hardware watchpoint.
116 This allows e.g. to use "unlimited" hardware watchpoints with the
117 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
118 watchpoints are slower than real hardware watchpoints but are
119 significantly faster than gdb software watchpoints.
123 ** The register_pretty_printer function in module gdb.printing now takes
124 an optional `replace' argument. If True, the new printer replaces any
127 ** The "maint set python print-stack on|off" command has been
128 deprecated and will be deleted in GDB 7.5.
129 A new command: "set python print-stack none|full|message" has
130 replaced it. Additionally, the default for "print-stack" is
131 now "message", which just prints the error message without
134 ** A prompt substitution hook (prompt_hook) is now available to the
137 ** A new Python module, gdb.prompt has been added to the GDB Python
138 modules library. This module provides functionality for
139 escape sequences in prompts (used by set/show
140 extended-prompt). These escape sequences are replaced by their
143 ** Python commands and convenience-functions located in
144 'data-directory'/python/gdb/command and
145 'data-directory'/python/gdb/function are now automatically loaded
148 ** Blocks now provide four new attributes. global_block and
149 static_block will return the global and static blocks
150 respectively. is_static and is_global are boolean attributes
151 that indicate if the block is one of those two types.
153 ** Symbols now provide the "type" attribute, the type of the symbol.
155 ** The "gdb.breakpoint" function has been deprecated in favor of
158 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
159 of a function. This class is based on the "finish" command
160 available in the CLI.
162 ** Type objects for struct and union types now allow access to
163 the fields using standard Python dictionary (mapping) methods.
164 For example, "some_type['myfield']" now works, as does
167 ** A new event "gdb.new_objfile" has been added, triggered by loading a
170 ** A new function, "deep_items" has been added to the gdb.types
171 module in the GDB Python modules library. This function returns
172 an iterator over the fields of a struct or union type. Unlike
173 the standard Python "iteritems" method, it will recursively traverse
174 any anonymous fields.
178 ** "*stopped" events can report several new "reason"s, such as
181 ** Breakpoint changes are now notified using new async records, like
182 "=breakpoint-modified".
184 ** New command -ada-task-info.
186 * libthread-db-search-path now supports two special values: $sdir and $pdir.
187 $sdir specifies the default system locations of shared libraries.
188 $pdir specifies the directory where the libpthread used by the application
191 GDB no longer looks in $sdir and $pdir after it has searched the directories
192 mentioned in libthread-db-search-path. If you want to search those
193 directories, they must be specified in libthread-db-search-path.
194 The default value of libthread-db-search-path on GNU/Linux and Solaris
195 systems is now "$sdir:$pdir".
197 $pdir is not supported by gdbserver, it is currently ignored.
198 $sdir is supported by gdbserver.
200 * New configure option --with-iconv-bin.
201 When using the internationalization support like the one in the GNU C
202 library, GDB will invoke the "iconv" program to get a list of supported
203 character sets. If this program lives in a non-standard location, one can
204 use this option to specify where to find it.
206 * When natively debugging programs on PowerPC BookE processors running
207 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
208 watchpoints, which specify a mask in addition to an address to watch.
209 The mask specifies that some bits of an address (the bits which are
210 reset in the mask) should be ignored when matching the address accessed
211 by the inferior against the watchpoint address. See the "PowerPC Embedded"
212 section in the user manual for more details.
214 * The new option --once causes GDBserver to stop listening for connections once
215 the first connection is made. The listening port used by GDBserver will
216 become available after that.
218 * New commands "info macros" and "alias" have been added.
220 * New function parameters suffix @entry specifies value of function parameter
221 at the time the function got called. Entry values are available only since
227 "!" is now an alias of the "shell" command.
228 Note that no space is needed between "!" and SHELL COMMAND.
232 watch EXPRESSION mask MASK_VALUE
233 The watch command now supports the mask argument which allows creation
234 of masked watchpoints, if the current architecture supports this feature.
236 info auto-load-scripts [REGEXP]
237 This command was formerly named "maintenance print section-scripts".
238 It is now generally useful and is no longer a maintenance-only command.
240 info macro [-all] [--] MACRO
241 The info macro command has new options `-all' and `--'. The first for
242 printing all definitions of a macro. The second for explicitly specifying
243 the end of arguments and the beginning of the macro name in case the macro
244 name starts with a hyphen.
246 collect[/s] EXPRESSIONS
247 The tracepoint collect command now takes an optional modifier "/s"
248 that directs it to dereference pointer-to-character types and
249 collect the bytes of memory up to a zero byte. The behavior is
250 similar to what you see when you use the regular print command on a
251 string. An optional integer following the "/s" sets a bound on the
252 number of bytes that will be collected.
255 The trace start command now interprets any supplied arguments as a
256 note to be recorded with the trace run, with an effect similar to
257 setting the variable trace-notes.
260 The trace stop command now interprets any arguments as a note to be
261 mentioned along with the tstatus report that the trace was stopped
262 with a command. The effect is similar to setting the variable
265 * Tracepoints can now be enabled and disabled at any time after a trace
266 experiment has been started using the standard "enable" and "disable"
267 commands. It is now possible to start a trace experiment with no enabled
268 tracepoints; GDB will display a warning, but will allow the experiment to
269 begin, assuming that tracepoints will be enabled as needed while the trace
272 * Fast tracepoints on 32-bit x86-architectures can now be placed at
273 locations with 4-byte instructions, when they were previously
274 limited to locations with instructions of 5 bytes or longer.
280 Set the GDB prompt, and allow escape sequences to be inserted to
281 display miscellaneous information (see 'help set extended-prompt'
282 for the list of sequences). This prompt (and any information
283 accessed through the escape sequences) is updated every time the
286 set print entry-values (both|compact|default|if-needed|no|only|preferred)
287 show print entry-values
288 Set printing of frame argument values at function entry. In some cases
289 GDB can determine the value of function argument which was passed by the
290 function caller, even if the value was modified inside the called function.
292 set debug entry-values
293 show debug entry-values
294 Control display of debugging info for determining frame argument values at
295 function entry and virtual tail call frames.
297 set basenames-may-differ
298 show basenames-may-differ
299 Set whether a source file may have multiple base names.
300 (A "base name" is the name of a file with the directory part removed.
301 Example: The base name of "/home/user/hello.c" is "hello.c".)
302 If set, GDB will canonicalize file names (e.g., expand symlinks)
303 before comparing them. Canonicalization is an expensive operation,
304 but it allows the same file be known by more than one base name.
305 If not set (the default), all source files are assumed to have just
306 one base name, and gdb will do file name comparisons more efficiently.
312 Set a user name and notes for the current and any future trace runs.
313 This is useful for long-running and/or disconnected traces, to
314 inform others (or yourself) as to who is running the trace, supply
315 contact information, or otherwise explain what is going on.
318 show trace-stop-notes
319 Set a note attached to the trace run, that is displayed when the
320 trace has been stopped by a tstop command. This is useful for
321 instance as an explanation, if you are stopping a trace run that was
322 started by someone else.
328 Dynamically enable a tracepoint in a started trace experiment.
332 Dynamically disable a tracepoint in a started trace experiment.
336 Set the user and notes of the trace run.
340 Query the current status of a tracepoint.
344 Query the minimum length of instruction at which a fast tracepoint may
347 * Dcache size (number of lines) and line-size are now runtime-configurable
348 via "set dcache line" and "set dcache line-size" commands.
352 Texas Instruments TMS320C6x tic6x-*-*
356 Renesas RL78 rl78-*-elf
358 *** Changes in GDB 7.3.1
360 * The build failure for NetBSD and OpenBSD targets have now been fixed.
362 *** Changes in GDB 7.3
364 * GDB has a new command: "thread find [REGEXP]".
365 It finds the thread id whose name, target id, or thread extra info
366 matches the given regular expression.
368 * The "catch syscall" command now works on mips*-linux* targets.
370 * The -data-disassemble MI command now supports modes 2 and 3 for
371 dumping the instruction opcodes.
373 * New command line options
375 -data-directory DIR Specify DIR as the "data-directory".
376 This is mostly for testing purposes.
378 * The "maint set python auto-load on|off" command has been renamed to
379 "set auto-load-scripts on|off".
381 * GDB has a new command: "set directories".
382 It is like the "dir" command except that it replaces the
383 source path list instead of augmenting it.
385 * GDB now understands thread names.
387 On GNU/Linux, "info threads" will display the thread name as set by
388 prctl or pthread_setname_np.
390 There is also a new command, "thread name", which can be used to
391 assign a name internally for GDB to display.
394 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
395 has been integrated into GDB.
399 ** The function gdb.Write now accepts an optional keyword 'stream'.
400 This keyword, when provided, will direct the output to either
401 stdout, stderr, or GDB's logging output.
403 ** Parameters can now be be sub-classed in Python, and in particular
404 you may implement the get_set_doc and get_show_doc functions.
405 This improves how Parameter set/show documentation is processed
406 and allows for more dynamic content.
408 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
409 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
410 have an is_valid method.
412 ** Breakpoints can now be sub-classed in Python, and in particular
413 you may implement a 'stop' function that is executed each time
414 the inferior reaches that breakpoint.
416 ** New function gdb.lookup_global_symbol looks up a global symbol.
418 ** GDB values in Python are now callable if the value represents a
419 function. For example, if 'some_value' represents a function that
420 takes two integer parameters and returns a value, you can call
421 that function like so:
423 result = some_value (10,20)
425 ** Module gdb.types has been added.
426 It contains a collection of utilities for working with gdb.Types objects:
427 get_basic_type, has_field, make_enum_dict.
429 ** Module gdb.printing has been added.
430 It contains utilities for writing and registering pretty-printers.
431 New classes: PrettyPrinter, SubPrettyPrinter,
432 RegexpCollectionPrettyPrinter.
433 New function: register_pretty_printer.
435 ** New commands "info pretty-printers", "enable pretty-printer" and
436 "disable pretty-printer" have been added.
438 ** gdb.parameter("directories") is now available.
440 ** New function gdb.newest_frame returns the newest frame in the
443 ** The gdb.InferiorThread class has a new "name" attribute. This
444 holds the thread's name.
446 ** Python Support for Inferior events.
447 Python scripts can add observers to be notified of events
448 occurring in the process being debugged.
449 The following events are currently supported:
450 - gdb.events.cont Continue event.
451 - gdb.events.exited Inferior exited event.
452 - gdb.events.stop Signal received, and Breakpoint hit events.
456 ** GDB now puts template parameters in scope when debugging in an
457 instantiation. For example, if you have:
459 template<int X> int func (void) { return X; }
461 then if you step into func<5>, "print X" will show "5". This
462 feature requires proper debuginfo support from the compiler; it
463 was added to GCC 4.5.
465 ** The motion commands "next", "finish", "until", and "advance" now
466 work better when exceptions are thrown. In particular, GDB will
467 no longer lose control of the inferior; instead, the GDB will
468 stop the inferior at the point at which the exception is caught.
469 This functionality requires a change in the exception handling
470 code that was introduced in GCC 4.5.
472 * GDB now follows GCC's rules on accessing volatile objects when
473 reading or writing target state during expression evaluation.
474 One notable difference to prior behavior is that "print x = 0"
475 no longer generates a read of x; the value of the assignment is
476 now always taken directly from the value being assigned.
478 * GDB now has some support for using labels in the program's source in
479 linespecs. For instance, you can use "advance label" to continue
480 execution to a label.
482 * GDB now has support for reading and writing a new .gdb_index
483 section. This section holds a fast index of DWARF debugging
484 information and can be used to greatly speed up GDB startup and
485 operation. See the documentation for `save gdb-index' for details.
487 * The "watch" command now accepts an optional "-location" argument.
488 When used, this causes GDB to watch the memory referred to by the
489 expression. Such a watchpoint is never deleted due to it going out
492 * GDB now supports thread debugging of core dumps on GNU/Linux.
494 GDB now activates thread debugging using the libthread_db library
495 when debugging GNU/Linux core dumps, similarly to when debugging
496 live processes. As a result, when debugging a core dump file, GDB
497 is now able to display pthread_t ids of threads. For example, "info
498 threads" shows the same output as when debugging the process when it
499 was live. In earlier releases, you'd see something like this:
502 * 1 LWP 6780 main () at main.c:10
504 While now you see this:
507 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
509 It is also now possible to inspect TLS variables when debugging core
512 When debugging a core dump generated on a machine other than the one
513 used to run GDB, you may need to point GDB at the correct
514 libthread_db library with the "set libthread-db-search-path"
515 command. See the user manual for more details on this command.
517 * When natively debugging programs on PowerPC BookE processors running
518 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
519 which stop execution of the inferior whenever it executes an instruction
520 at any address within the specified range. See the "PowerPC Embedded"
521 section in the user manual for more details.
523 * New features in the GDB remote stub, GDBserver
525 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
526 and i686 LynxOS (version 5.x).
528 ** GDBserver is now supported on Blackfin Linux.
530 * New native configurations
532 ia64 HP-UX ia64-*-hpux*
536 Analog Devices, Inc. Blackfin Processor bfin-*
538 * Ada task switching is now supported on sparc-elf targets when
539 debugging a program using the Ravenscar Profile. For more information,
540 see the "Tasking Support when using the Ravenscar Profile" section
541 in the GDB user manual.
543 * Guile support was removed.
545 * New features in the GNU simulator
547 ** The --map-info flag lists all known core mappings.
549 ** CFI flashes may be simulated via the "cfi" device.
551 *** Changes in GDB 7.2
553 * Shared library support for remote targets by default
555 When GDB is configured for a generic, non-OS specific target, like
556 for example, --target=arm-eabi or one of the many *-*-elf targets,
557 GDB now queries remote stubs for loaded shared libraries using the
558 `qXfer:libraries:read' packet. Previously, shared library support
559 was always disabled for such configurations.
563 ** Argument Dependent Lookup (ADL)
565 In C++ ADL lookup directs function search to the namespaces of its
566 arguments even if the namespace has not been imported.
576 Here the compiler will search for `foo' in the namespace of 'b'
577 and find A::foo. GDB now supports this. This construct is commonly
578 used in the Standard Template Library for operators.
580 ** Improved User Defined Operator Support
582 In addition to member operators, GDB now supports lookup of operators
583 defined in a namespace and imported with a `using' directive, operators
584 defined in the global scope, operators imported implicitly from an
585 anonymous namespace, and the ADL operators mentioned in the previous
587 GDB now also supports proper overload resolution for all the previously
588 mentioned flavors of operators.
590 ** static const class members
592 Printing of static const class members that are initialized in the
593 class definition has been fixed.
595 * Windows Thread Information Block access.
597 On Windows targets, GDB now supports displaying the Windows Thread
598 Information Block (TIB) structure. This structure is visible either
599 by using the new command `info w32 thread-information-block' or, by
600 dereferencing the new convenience variable named `$_tlb', a
601 thread-specific pointer to the TIB. This feature is also supported
602 when remote debugging using GDBserver.
606 Static tracepoints are calls in the user program into a tracing
607 library. One such library is a port of the LTTng kernel tracer to
608 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
609 When debugging with GDBserver, GDB now supports combining the GDB
610 tracepoint machinery with such libraries. For example: the user can
611 use GDB to probe a static tracepoint marker (a call from the user
612 program into the tracing library) with the new "strace" command (see
613 "New commands" below). This creates a "static tracepoint" in the
614 breakpoint list, that can be manipulated with the same feature set
615 as fast and regular tracepoints. E.g., collect registers, local and
616 global variables, collect trace state variables, and define
617 tracepoint conditions. In addition, the user can collect extra
618 static tracepoint marker specific data, by collecting the new
619 $_sdata internal variable. When analyzing the trace buffer, you can
620 inspect $_sdata like any other variable available to GDB. For more
621 information, see the "Tracepoints" chapter in GDB user manual. New
622 remote packets have been defined to support static tracepoints, see
623 the "New remote packets" section below.
625 * Better reconstruction of tracepoints after disconnected tracing
627 GDB will attempt to download the original source form of tracepoint
628 definitions when starting a trace run, and then will upload these
629 upon reconnection to the target, resulting in a more accurate
630 reconstruction of the tracepoints that are in use on the target.
634 You can now exercise direct control over the ways that GDB can
635 affect your program. For instance, you can disallow the setting of
636 breakpoints, so that the program can run continuously (assuming
637 non-stop mode). In addition, the "observer" variable is available
638 to switch all of the different controls; in observer mode, GDB
639 cannot affect the target's behavior at all, which is useful for
640 tasks like diagnosing live systems in the field.
642 * The new convenience variable $_thread holds the number of the
649 Return the address of the Windows Thread Information Block of a given thread.
653 In response to several of the tracepoint packets, the target may now
654 also respond with a number of intermediate `qRelocInsn' request
655 packets before the final result packet, to have GDB handle
656 relocating an instruction to execute at a different address. This
657 is particularly useful for stubs that support fast tracepoints. GDB
658 reports support for this feature in the qSupported packet.
662 List static tracepoint markers in the target program.
666 List static tracepoint markers at a given address in the target
669 qXfer:statictrace:read
671 Read the static trace data collected (by a `collect $_sdata'
672 tracepoint action). The remote stub reports support for this packet
673 to gdb's qSupported query.
677 Send the current settings of GDB's permission flags.
681 Send part of the source (textual) form of a tracepoint definition,
682 which includes location, conditional, and action list.
684 * The source command now accepts a -s option to force searching for the
685 script in the source search path even if the script name specifies
688 * New features in the GDB remote stub, GDBserver
690 - GDBserver now support tracepoints (including fast tracepoints, and
691 static tracepoints). The feature is currently supported by the
692 i386-linux and amd64-linux builds. See the "Tracepoints support
693 in gdbserver" section in the manual for more information.
695 GDBserver JIT compiles the tracepoint's conditional agent
696 expression bytecode into native code whenever possible for low
697 overhead dynamic tracepoints conditionals. For such tracepoints,
698 an expression that examines program state is evaluated when the
699 tracepoint is reached, in order to determine whether to capture
700 trace data. If the condition is simple and false, processing the
701 tracepoint finishes very quickly and no data is gathered.
703 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
704 for static tracepoints support.
706 - GDBserver now supports x86_64 Windows 64-bit debugging.
708 * GDB now sends xmlRegisters= in qSupported packet to indicate that
709 it understands register description.
711 * The --batch flag now disables pagination and queries.
713 * X86 general purpose registers
715 GDB now supports reading/writing byte, word and double-word x86
716 general purpose registers directly. This means you can use, say,
717 $ah or $ax to refer, respectively, to the byte register AH and
718 16-bit word register AX that are actually portions of the 32-bit
719 register EAX or 64-bit register RAX.
721 * The `commands' command now accepts a range of breakpoints to modify.
722 A plain `commands' following a command that creates multiple
723 breakpoints affects all the breakpoints set by that command. This
724 applies to breakpoints set by `rbreak', and also applies when a
725 single `break' command creates multiple breakpoints (e.g.,
726 breakpoints on overloaded c++ functions).
728 * The `rbreak' command now accepts a filename specification as part of
729 its argument, limiting the functions selected by the regex to those
730 in the specified file.
732 * Support for remote debugging Windows and SymbianOS shared libraries
733 from Unix hosts has been improved. Non Windows GDB builds now can
734 understand target reported file names that follow MS-DOS based file
735 system semantics, such as file names that include drive letters and
736 use the backslash character as directory separator. This makes it
737 possible to transparently use the "set sysroot" and "set
738 solib-search-path" on Unix hosts to point as host copies of the
739 target's shared libraries. See the new command "set
740 target-file-system-kind" described below, and the "Commands to
741 specify files" section in the user manual for more information.
745 eval template, expressions...
746 Convert the values of one or more expressions under the control
747 of the string template to a command line, and call it.
749 set target-file-system-kind unix|dos-based|auto
750 show target-file-system-kind
751 Set or show the assumed file system kind for target reported file
754 save breakpoints <filename>
755 Save all current breakpoint definitions to a file suitable for use
756 in a later debugging session. To read the saved breakpoint
757 definitions, use the `source' command.
759 `save tracepoints' is a new alias for `save-tracepoints'. The latter
762 info static-tracepoint-markers
763 Display information about static tracepoint markers in the target.
765 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
766 Define a static tracepoint by probing a marker at the given
767 function, line, address, or marker ID.
771 Enable and disable observer mode.
773 set may-write-registers on|off
774 set may-write-memory on|off
775 set may-insert-breakpoints on|off
776 set may-insert-tracepoints on|off
777 set may-insert-fast-tracepoints on|off
778 set may-interrupt on|off
779 Set individual permissions for GDB effects on the target. Note that
780 some of these settings can have undesirable or surprising
781 consequences, particularly when changed in the middle of a session.
782 For instance, disabling the writing of memory can prevent
783 breakpoints from being inserted, cause single-stepping to fail, or
784 even crash your program, if you disable after breakpoints have been
785 inserted. However, GDB should not crash.
787 set record memory-query on|off
788 show record memory-query
789 Control whether to stop the inferior if memory changes caused
790 by an instruction cannot be recorded.
795 The disassemble command now supports "start,+length" form of two arguments.
799 ** GDB now provides a new directory location, called the python directory,
800 where Python scripts written for GDB can be installed. The location
801 of that directory is <data-directory>/python, where <data-directory>
802 is the GDB data directory. For more details, see section `Scripting
803 GDB using Python' in the manual.
805 ** The GDB Python API now has access to breakpoints, symbols, symbol
806 tables, program spaces, inferiors, threads and frame's code blocks.
807 Additionally, GDB Parameters can now be created from the API, and
808 manipulated via set/show in the CLI.
810 ** New functions gdb.target_charset, gdb.target_wide_charset,
811 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
813 ** New exception gdb.GdbError.
815 ** Pretty-printers are now also looked up in the current program space.
817 ** Pretty-printers can now be individually enabled and disabled.
819 ** GDB now looks for names of Python scripts to auto-load in a
820 special section named `.debug_gdb_scripts', in addition to looking
821 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
823 * Tracepoint actions were unified with breakpoint commands. In particular,
824 there are no longer differences in "info break" output for breakpoints and
825 tracepoints and the "commands" command can be used for both tracepoints and
830 ARM Symbian arm*-*-symbianelf*
832 * D language support.
833 GDB now supports debugging programs written in the D programming
836 * GDB now supports the extended ptrace interface for PowerPC which is
837 available since Linux kernel version 2.6.34. This automatically enables
838 any hardware breakpoints and additional hardware watchpoints available in
839 the processor. The old ptrace interface exposes just one hardware
840 watchpoint and no hardware breakpoints.
842 * GDB is now able to use the Data Value Compare (DVC) register available on
843 embedded PowerPC processors to implement in hardware simple watchpoint
844 conditions of the form:
846 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
848 This works in native GDB running on Linux kernels with the extended ptrace
849 interface mentioned above.
851 *** Changes in GDB 7.1
857 GDB now supports importing of namespaces in C++. This enables the
858 user to inspect variables from imported namespaces. Support for
859 namepace aliasing has also been added. So, if a namespace is
860 aliased in the current scope (e.g. namepace C=A; ) the user can
861 print variables using the alias (e.g. (gdb) print C::x).
865 All known bugs relating to the printing of virtual base class were
866 fixed. It is now possible to call overloaded static methods using a
871 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
872 and reinterpret_cast<> are now handled by the C++ expression parser.
876 Xilinx MicroBlaze microblaze-*-*
881 Xilinx MicroBlaze microblaze
884 * Multi-program debugging.
886 GDB now has support for multi-program (a.k.a. multi-executable or
887 multi-exec) debugging. This allows for debugging multiple inferiors
888 simultaneously each running a different program under the same GDB
889 session. See "Debugging Multiple Inferiors and Programs" in the
890 manual for more information. This implied some user visible changes
891 in the multi-inferior support. For example, "info inferiors" now
892 lists inferiors that are not running yet or that have exited
893 already. See also "New commands" and "New options" below.
895 * New tracing features
897 GDB's tracepoint facility now includes several new features:
899 ** Trace state variables
901 GDB tracepoints now include support for trace state variables, which
902 are variables managed by the target agent during a tracing
903 experiment. They are useful for tracepoints that trigger each
904 other, so for instance one tracepoint can count hits in a variable,
905 and then a second tracepoint has a condition that is true when the
906 count reaches a particular value. Trace state variables share the
907 $-syntax of GDB convenience variables, and can appear in both
908 tracepoint actions and condition expressions. Use the "tvariable"
909 command to create, and "info tvariables" to view; see "Trace State
910 Variables" in the manual for more detail.
914 GDB now includes an option for defining fast tracepoints, which
915 targets may implement more efficiently, such as by installing a jump
916 into the target agent rather than a trap instruction. The resulting
917 speedup can be by two orders of magnitude or more, although the
918 tradeoff is that some program locations on some target architectures
919 might not allow fast tracepoint installation, for instance if the
920 instruction to be replaced is shorter than the jump. To request a
921 fast tracepoint, use the "ftrace" command, with syntax identical to
922 the regular trace command.
924 ** Disconnected tracing
926 It is now possible to detach GDB from the target while it is running
927 a trace experiment, then reconnect later to see how the experiment
928 is going. In addition, a new variable disconnected-tracing lets you
929 tell the target agent whether to continue running a trace if the
930 connection is lost unexpectedly.
934 GDB now has the ability to save the trace buffer into a file, and
935 then use that file as a target, similarly to you can do with
936 corefiles. You can select trace frames, print data that was
937 collected in them, and use tstatus to display the state of the
938 tracing run at the moment that it was saved. To create a trace
939 file, use "tsave <filename>", and to use it, do "target tfile
942 ** Circular trace buffer
944 You can ask the target agent to handle the trace buffer as a
945 circular buffer, discarding the oldest trace frames to make room for
946 newer ones, by setting circular-trace-buffer to on. This feature may
947 not be available for all target agents.
952 The disassemble command, when invoked with two arguments, now requires
953 the arguments to be comma-separated.
956 The info variables command now displays variable definitions. Files
957 which only declare a variable are not shown.
960 The source command is now capable of sourcing Python scripts.
961 This feature is dependent on the debugger being build with Python
964 Related to this enhancement is also the introduction of a new command
965 "set script-extension" (see below).
967 * New commands (for set/show, see "New options" below)
969 record save [<FILENAME>]
970 Save a file (in core file format) containing the process record
971 execution log for replay debugging at a later time.
973 record restore <FILENAME>
974 Restore the process record execution log that was saved at an
975 earlier time, for replay debugging.
977 add-inferior [-copies <N>] [-exec <FILENAME>]
980 clone-inferior [-copies <N>] [ID]
981 Make a new inferior ready to execute the same program another
987 maint info program-spaces
988 List the program spaces loaded into GDB.
990 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
991 show remote interrupt-sequence
992 Allow the user to select one of ^C, a BREAK signal or BREAK-g
993 as the sequence to the remote target in order to interrupt the execution.
994 Ctrl-C is a default. Some system prefers BREAK which is high level of
995 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
996 Magic SysRq g. It is BREAK signal and character 'g'.
998 set remote interrupt-on-connect [on | off]
999 show remote interrupt-on-connect
1000 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1001 remote target when gdb connects to it. This is needed when you debug
1004 set remotebreak [on | off]
1006 Deprecated. Use "set/show remote interrupt-sequence" instead.
1008 tvariable $NAME [ = EXP ]
1009 Create or modify a trace state variable.
1012 List trace state variables and their values.
1014 delete tvariable $NAME ...
1015 Delete one or more trace state variables.
1018 Evaluate the given expressions without collecting anything into the
1019 trace buffer. (Valid in tracepoint actions only.)
1021 ftrace FN / FILE:LINE / *ADDR
1022 Define a fast tracepoint at the given function, line, or address.
1024 * New expression syntax
1026 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1027 GDB now parses 0b101010 identically with 42.
1031 set follow-exec-mode new|same
1032 show follow-exec-mode
1033 Control whether GDB reuses the same inferior across an exec call or
1034 creates a new one. This is useful to be able to restart the old
1035 executable after the inferior having done an exec call.
1037 set default-collect EXPR, ...
1038 show default-collect
1039 Define a list of expressions to be collected at each tracepoint.
1040 This is a useful way to ensure essential items are not overlooked,
1041 such as registers or a critical global variable.
1043 set disconnected-tracing
1044 show disconnected-tracing
1045 If set to 1, the target is instructed to continue tracing if it
1046 loses its connection to GDB. If 0, the target is to stop tracing
1049 set circular-trace-buffer
1050 show circular-trace-buffer
1051 If set to on, the target is instructed to use a circular trace buffer
1052 and discard the oldest trace frames instead of stopping the trace due
1053 to a full trace buffer. If set to off, the trace stops when the buffer
1054 fills up. Some targets may not support this.
1056 set script-extension off|soft|strict
1057 show script-extension
1058 If set to "off", the debugger does not perform any script language
1059 recognition, and all sourced files are assumed to be GDB scripts.
1060 If set to "soft" (the default), files are sourced according to
1061 filename extension, falling back to GDB scripts if the first
1063 If set to "strict", files are sourced according to filename extension.
1065 set ada trust-PAD-over-XVS on|off
1066 show ada trust-PAD-over-XVS
1067 If off, activate a workaround against a bug in the debugging information
1068 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1069 the GCC sources for more information about the GNAT encoding and
1070 PAD types in particular). It is always safe to set this option to
1071 off, but this introduces a slight performance penalty. The default
1074 * Python API Improvements
1076 ** GDB provides the new class gdb.LazyString. This is useful in
1077 some pretty-printing cases. The new method gdb.Value.lazy_string
1078 provides a simple way to create objects of this type.
1080 ** The fields returned by gdb.Type.fields now have an
1081 `is_base_class' attribute.
1083 ** The new method gdb.Type.range returns the range of an array type.
1085 ** The new method gdb.parse_and_eval can be used to parse and
1086 evaluate an expression.
1088 * New remote packets
1091 Define a trace state variable.
1094 Get the current value of a trace state variable.
1097 Set desired tracing behavior upon disconnection.
1100 Set the trace buffer to be linear or circular.
1103 Get data about the tracepoints currently in use.
1107 Process record now works correctly with hardware watchpoints.
1109 Multiple bug fixes have been made to the mips-irix port, making it
1110 much more reliable. In particular:
1111 - Debugging threaded applications is now possible again. Previously,
1112 GDB would hang while starting the program, or while waiting for
1113 the program to stop at a breakpoint.
1114 - Attaching to a running process no longer hangs.
1115 - An error occurring while loading a core file has been fixed.
1116 - Changing the value of the PC register now works again. This fixes
1117 problems observed when using the "jump" command, or when calling
1118 a function from GDB, or even when assigning a new value to $pc.
1119 - With the "finish" and "return" commands, the return value for functions
1120 returning a small array is now correctly printed.
1121 - It is now possible to break on shared library code which gets executed
1122 during a shared library init phase (code executed while executing
1123 their .init section). Previously, the breakpoint would have no effect.
1124 - GDB is now able to backtrace through the signal handler for
1125 non-threaded programs.
1127 PIE (Position Independent Executable) programs debugging is now supported.
1128 This includes debugging execution of PIC (Position Independent Code) shared
1129 libraries although for that, it should be possible to run such libraries as an
1132 *** Changes in GDB 7.0
1134 * GDB now has an interface for JIT compilation. Applications that
1135 dynamically generate code can create symbol files in memory and register
1136 them with GDB. For users, the feature should work transparently, and
1137 for JIT developers, the interface is documented in the GDB manual in the
1138 "JIT Compilation Interface" chapter.
1140 * Tracepoints may now be conditional. The syntax is as for
1141 breakpoints; either an "if" clause appended to the "trace" command,
1142 or the "condition" command is available. GDB sends the condition to
1143 the target for evaluation using the same bytecode format as is used
1144 for tracepoint actions.
1146 * The disassemble command now supports: an optional /r modifier, print the
1147 raw instructions in hex as well as in symbolic form, and an optional /m
1148 modifier to print mixed source+assembly.
1150 * Process record and replay
1152 In a architecture environment that supports ``process record and
1153 replay'', ``process record and replay'' target can record a log of
1154 the process execution, and replay it with both forward and reverse
1157 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1158 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1159 set execution-direction {forward|reverse}, for targets that support
1162 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1163 feature is available with a native GDB running on kernel version
1166 * GDB now has support for multi-byte and wide character sets on the
1167 target. Strings whose character type is wchar_t, char16_t, or
1168 char32_t are now correctly printed. GDB supports wide- and unicode-
1169 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1170 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1171 `printf'. This feature requires iconv to work properly; if your
1172 system does not have a working iconv, GDB can use GNU libiconv. See
1173 the installation instructions for more information.
1175 * GDB now supports automatic retrieval of shared library files from
1176 remote targets. To use this feature, specify a system root that begins
1177 with the `remote:' prefix, either via the `set sysroot' command or via
1178 the `--with-sysroot' configure-time option.
1180 * "info sharedlibrary" now takes an optional regex of libraries to show,
1181 and it now reports if a shared library has no debugging information.
1183 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1184 now complete on file names.
1186 * When completing in expressions, gdb will attempt to limit
1187 completions to allowable structure or union fields, where appropriate.
1188 For instance, consider:
1190 # struct example { int f1; double f2; };
1191 # struct example variable;
1194 If the user types TAB at the end of this command line, the available
1195 completions will be "f1" and "f2".
1197 * Inlined functions are now supported. They show up in backtraces, and
1198 the "step", "next", and "finish" commands handle them automatically.
1200 * GDB now supports the token-splicing (##) and stringification (#)
1201 operators when expanding macros. It also supports variable-arity
1204 * GDB now supports inspecting extra signal information, exported by
1205 the new $_siginfo convenience variable. The feature is currently
1206 implemented on linux ARM, i386 and amd64.
1208 * GDB can now display the VFP floating point registers and NEON vector
1209 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1210 can provide these registers (requires Linux 2.6.30 or later). Remote
1211 and simulator targets may also provide them.
1213 * New remote packets
1216 Search memory for a sequence of bytes.
1219 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1220 operation over reliable transport links. Use of this packet is
1221 controlled by the `set remote noack-packet' command.
1224 Kill the process with the specified process ID. Use this in preference
1225 to `k' when multiprocess protocol extensions are supported.
1228 Obtains additional operating system information
1232 Read or write additional signal information.
1234 * Removed remote protocol undocumented extension
1236 An undocumented extension to the remote protocol's `S' stop reply
1237 packet that permited the stub to pass a process id was removed.
1238 Remote servers should use the `T' stop reply packet instead.
1240 * GDB now supports multiple function calling conventions according to the
1241 DWARF-2 DW_AT_calling_convention function attribute.
1243 * The SH target utilizes the aforementioned change to distinguish between gcc
1244 and Renesas calling convention. It also adds the new CLI commands
1245 `set/show sh calling-convention'.
1247 * GDB can now read compressed debug sections, as produced by GNU gold
1248 with the --compress-debug-sections=zlib flag.
1250 * 64-bit core files are now supported on AIX.
1252 * Thread switching is now supported on Tru64.
1254 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1255 which will be allocated using malloc later in program execution.
1257 * The qXfer:libraries:read remote procotol packet now allows passing a
1258 list of section offsets.
1260 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1261 conditions handling signals delivered during attach or thread creation
1262 have also been fixed.
1264 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1265 From the user's standpoint, all unqualified instances of True and False
1266 are treated as the standard definitions, regardless of context.
1268 * GDB now parses C++ symbol and type names more flexibly. For
1271 template<typename T> class C { };
1274 GDB will now correctly handle all of:
1276 ptype C<char const *>
1277 ptype C<char const*>
1278 ptype C<const char *>
1279 ptype C<const char*>
1281 * New features in the GDB remote stub, gdbserver
1283 - The "--wrapper" command-line argument tells gdbserver to use a
1284 wrapper program to launch programs for debugging.
1286 - On PowerPC and S/390 targets, it is now possible to use a single
1287 gdbserver executable to debug both 32-bit and 64-bit programs.
1288 (This requires gdbserver itself to be built as a 64-bit executable.)
1290 - gdbserver uses the new noack protocol mode for TCP connections to
1291 reduce communications latency, if also supported and enabled in GDB.
1293 - Support for the sparc64-linux-gnu target is now included in
1296 - The amd64-linux build of gdbserver now supports debugging both
1297 32-bit and 64-bit programs.
1299 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1300 now support hardware watchpoints, and will use them automatically
1305 GDB now has support for scripting using Python. Whether this is
1306 available is determined at configure time.
1308 New GDB commands can now be written in Python.
1310 * Ada tasking support
1312 Ada tasks can now be inspected in GDB. The following commands have
1316 Print the list of Ada tasks.
1318 Print detailed information about task number N.
1320 Print the task number of the current task.
1322 Switch the context of debugging to task number N.
1324 * Support for user-defined prefixed commands. The "define" command can
1325 add new commands to existing prefixes, e.g. "target".
1327 * Multi-inferior, multi-process debugging.
1329 GDB now has generalized support for multi-inferior debugging. See
1330 "Debugging Multiple Inferiors" in the manual for more information.
1331 Although availability still depends on target support, the command
1332 set is more uniform now. The GNU/Linux specific multi-forks support
1333 has been migrated to this new framework. This implied some user
1334 visible changes; see "New commands" and also "Removed commands"
1337 * Target descriptions can now describe the target OS ABI. See the
1338 "Target Description Format" section in the user manual for more
1341 * Target descriptions can now describe "compatible" architectures
1342 to indicate that the target can execute applications for a different
1343 architecture in addition to those for the main target architecture.
1344 See the "Target Description Format" section in the user manual for
1347 * Multi-architecture debugging.
1349 GDB now includes general supports for debugging applications on
1350 hybrid systems that use more than one single processor architecture
1351 at the same time. Each such hybrid architecture still requires
1352 specific support to be added. The only hybrid architecture supported
1353 in this version of GDB is the Cell Broadband Engine.
1355 * GDB now supports integrated debugging of Cell/B.E. applications that
1356 use both the PPU and SPU architectures. To enable support for hybrid
1357 Cell/B.E. debugging, you need to configure GDB to support both the
1358 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1359 --enable-targets configure option.
1361 * Non-stop mode debugging.
1363 For some targets, GDB now supports an optional mode of operation in
1364 which you can examine stopped threads while other threads continue
1365 to execute freely. This is referred to as non-stop mode, with the
1366 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1367 section in the user manual for more information.
1369 To be able to support remote non-stop debugging, a remote stub needs
1370 to implement the non-stop mode remote protocol extensions, as
1371 described in the "Remote Non-Stop" section of the user manual. The
1372 GDB remote stub, gdbserver, has been adjusted to support these
1373 extensions on linux targets.
1375 * New commands (for set/show, see "New options" below)
1377 catch syscall [NAME(S) | NUMBER(S)]
1378 Catch system calls. Arguments, which should be names of system
1379 calls or their numbers, mean catch only those syscalls. Without
1380 arguments, every syscall will be caught. When the inferior issues
1381 any of the specified syscalls, GDB will stop and announce the system
1382 call, both when it is called and when its call returns. This
1383 feature is currently available with a native GDB running on the
1384 Linux Kernel, under the following architectures: x86, x86_64,
1385 PowerPC and PowerPC64.
1387 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1389 Search memory for a sequence of bytes.
1391 maint set python print-stack
1392 maint show python print-stack
1393 Show a stack trace when an error is encountered in a Python script.
1396 Invoke CODE by passing it to the Python interpreter.
1401 These allow macros to be defined, undefined, and listed
1405 Show operating system information about processes.
1408 List the inferiors currently under GDB's control.
1411 Switch focus to inferior number NUM.
1414 Detach from inferior number NUM.
1417 Kill inferior number NUM.
1421 set spu stop-on-load
1422 show spu stop-on-load
1423 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1425 set spu auto-flush-cache
1426 show spu auto-flush-cache
1427 Control whether to automatically flush the software-managed cache
1428 during Cell/B.E. debugging.
1430 set sh calling-convention
1431 show sh calling-convention
1432 Control the calling convention used when calling SH target functions.
1435 show debug timestamp
1436 Control display of timestamps with GDB debugging output.
1438 set disassemble-next-line
1439 show disassemble-next-line
1440 Control display of disassembled source lines or instructions when
1443 set remote noack-packet
1444 show remote noack-packet
1445 Set/show the use of remote protocol QStartNoAckMode packet. See above
1446 under "New remote packets."
1448 set remote query-attached-packet
1449 show remote query-attached-packet
1450 Control use of remote protocol `qAttached' (query-attached) packet.
1452 set remote read-siginfo-object
1453 show remote read-siginfo-object
1454 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1457 set remote write-siginfo-object
1458 show remote write-siginfo-object
1459 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1462 set remote reverse-continue
1463 show remote reverse-continue
1464 Control use of remote protocol 'bc' (reverse-continue) packet.
1466 set remote reverse-step
1467 show remote reverse-step
1468 Control use of remote protocol 'bs' (reverse-step) packet.
1470 set displaced-stepping
1471 show displaced-stepping
1472 Control displaced stepping mode. Displaced stepping is a way to
1473 single-step over breakpoints without removing them from the debuggee.
1474 Also known as "out-of-line single-stepping".
1477 show debug displaced
1478 Control display of debugging info for displaced stepping.
1480 maint set internal-error
1481 maint show internal-error
1482 Control what GDB does when an internal error is detected.
1484 maint set internal-warning
1485 maint show internal-warning
1486 Control what GDB does when an internal warning is detected.
1491 Use a wrapper program to launch programs for debugging.
1493 set multiple-symbols (all|ask|cancel)
1494 show multiple-symbols
1495 The value of this variable can be changed to adjust the debugger behavior
1496 when an expression or a breakpoint location contains an ambiguous symbol
1497 name (an overloaded function name, for instance).
1499 set breakpoint always-inserted
1500 show breakpoint always-inserted
1501 Keep breakpoints always inserted in the target, as opposed to inserting
1502 them when resuming the target, and removing them when the target stops.
1503 This option can improve debugger performance on slow remote targets.
1505 set arm fallback-mode (arm|thumb|auto)
1506 show arm fallback-mode
1507 set arm force-mode (arm|thumb|auto)
1509 These commands control how ARM GDB determines whether instructions
1510 are ARM or Thumb. The default for both settings is auto, which uses
1511 the current CPSR value for instructions without symbols; previous
1512 versions of GDB behaved as if "set arm fallback-mode arm".
1514 set disable-randomization
1515 show disable-randomization
1516 Standalone programs run with the virtual address space randomization enabled
1517 by default on some platforms. This option keeps the addresses stable across
1518 multiple debugging sessions.
1522 Control whether other threads are stopped or not when some thread hits
1527 Requests that asynchronous execution is enabled in the target, if available.
1528 In this case, it's possible to resume target in the background, and interact
1529 with GDB while the target is running. "show target-async" displays the
1530 current state of asynchronous execution of the target.
1532 set target-wide-charset
1533 show target-wide-charset
1534 The target-wide-charset is the name of the character set that GDB
1535 uses when printing characters whose type is wchar_t.
1537 set tcp auto-retry (on|off)
1539 set tcp connect-timeout
1540 show tcp connect-timeout
1541 These commands allow GDB to retry failed TCP connections to a remote stub
1542 with a specified timeout period; this is useful if the stub is launched
1543 in parallel with GDB but may not be ready to accept connections immediately.
1545 set libthread-db-search-path
1546 show libthread-db-search-path
1547 Control list of directories which GDB will search for appropriate
1550 set schedule-multiple (on|off)
1551 show schedule-multiple
1552 Allow GDB to resume all threads of all processes or only threads of
1553 the current process.
1557 Use more aggressive caching for accesses to the stack. This improves
1558 performance of remote debugging (particularly backtraces) without
1559 affecting correctness.
1561 set interactive-mode (on|off|auto)
1562 show interactive-mode
1563 Control whether GDB runs in interactive mode (on) or not (off).
1564 When in interactive mode, GDB waits for the user to answer all
1565 queries. Otherwise, GDB does not wait and assumes the default
1566 answer. When set to auto (the default), GDB determines which
1567 mode to use based on the stdin settings.
1572 For program forks, this is replaced by the new more generic `info
1573 inferiors' command. To list checkpoints, you can still use the
1574 `info checkpoints' command, which was an alias for the `info forks'
1578 Replaced by the new `inferior' command. To switch between
1579 checkpoints, you can still use the `restart' command, which was an
1580 alias for the `fork' command.
1583 This is removed, since some targets don't have a notion of
1584 processes. To switch between processes, you can still use the
1585 `inferior' command using GDB's own inferior number.
1588 For program forks, this is replaced by the new more generic `kill
1589 inferior' command. To delete a checkpoint, you can still use the
1590 `delete checkpoint' command, which was an alias for the `delete
1594 For program forks, this is replaced by the new more generic `detach
1595 inferior' command. To detach a checkpoint, you can still use the
1596 `detach checkpoint' command, which was an alias for the `detach
1599 * New native configurations
1601 x86/x86_64 Darwin i[34567]86-*-darwin*
1603 x86_64 MinGW x86_64-*-mingw*
1607 Lattice Mico32 lm32-*
1608 x86 DICOS i[34567]86-*-dicos*
1609 x86_64 DICOS x86_64-*-dicos*
1612 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1613 (mingw32ce) debugging.
1619 These commands were actually not implemented on any target.
1621 *** Changes in GDB 6.8
1623 * New native configurations
1625 NetBSD/hppa hppa*-*netbsd*
1626 Xtensa GNU/Linux xtensa*-*-linux*
1630 NetBSD/hppa hppa*-*-netbsd*
1631 Xtensa GNU/Lunux xtensa*-*-linux*
1633 * Change in command line behavior -- corefiles vs. process ids.
1635 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1636 attaching to process NUMBER fails, GDB no longer attempts to open a
1637 core file named NUMBER. Attaching to a program using the -c option
1638 is no longer supported. Instead, use the '-p' or '--pid' options.
1640 * GDB can now be built as a native debugger for debugging Windows x86
1641 (mingw32) Portable Executable (PE) programs.
1643 * Pending breakpoints no longer change their number when their address
1646 * GDB now supports breakpoints with multiple locations,
1647 including breakpoints on C++ constructors, inside C++ templates,
1648 and in inlined functions.
1650 * GDB's ability to debug optimized code has been improved. GDB more
1651 accurately identifies function bodies and lexical blocks that occupy
1652 more than one contiguous range of addresses.
1654 * Target descriptions can now describe registers for PowerPC.
1656 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1657 registers on PowerPC targets.
1659 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1660 targets even when the libthread_db library is not available.
1662 * The GDB remote stub, gdbserver, now supports the new file transfer
1663 commands (remote put, remote get, and remote delete).
1665 * The GDB remote stub, gdbserver, now supports run and attach in
1666 extended-remote mode.
1668 * hppa*64*-*-hpux11* target broken
1669 The debugger is unable to start a program and fails with the following
1670 error: "Error trying to get information about dynamic linker".
1671 The gdb-6.7 release is also affected.
1673 * GDB now supports the --enable-targets= configure option to allow
1674 building a single GDB executable that supports multiple remote
1675 target architectures.
1677 * GDB now supports debugging C and C++ programs which use the
1678 Decimal Floating Point extension. In addition, the PowerPC target
1679 now has a set of pseudo-registers to inspect decimal float values
1680 stored in two consecutive float registers.
1682 * The -break-insert MI command can optionally create pending
1685 * Improved support for debugging Ada
1686 Many improvements to the Ada language support have been made. These
1688 - Better support for Ada2005 interface types
1689 - Improved handling of arrays and slices in general
1690 - Better support for Taft-amendment types
1691 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1693 - Improved command completion in Ada
1696 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1701 set print frame-arguments (all|scalars|none)
1702 show print frame-arguments
1703 The value of this variable can be changed to control which argument
1704 values should be printed by the debugger when displaying a frame.
1709 Transfer files to and from a remote target, and delete remote files.
1716 Transfer files to and from a remote target, and delete remote files.
1718 * New remote packets
1725 Open, close, read, write, and delete files on the remote system.
1728 Attach to an existing process on the remote system, in extended-remote
1732 Run a new process on the remote system, in extended-remote mode.
1734 *** Changes in GDB 6.7
1736 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1737 bfd, libiberty and opcodes, as revealed by static analysis donated by
1738 Coverity, Inc. (http://scan.coverity.com).
1740 * When looking up multiply-defined global symbols, GDB will now prefer the
1741 symbol definition in the current shared library if it was built using the
1742 -Bsymbolic linker option.
1744 * When the Text User Interface (TUI) is not configured, GDB will now
1745 recognize the -tui command-line option and print a message that the TUI
1748 * The GDB remote stub, gdbserver, now has lower overhead for high
1749 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1751 * GDB for MIPS targets now autodetects whether a remote target provides
1752 32-bit or 64-bit register values.
1754 * Support for C++ member pointers has been improved.
1756 * GDB now understands XML target descriptions, which specify the
1757 target's overall architecture. GDB can read a description from
1758 a local file or over the remote serial protocol.
1760 * Vectors of single-byte data use a new integer type which is not
1761 automatically displayed as character or string data.
1763 * The /s format now works with the print command. It displays
1764 arrays of single-byte integers and pointers to single-byte integers
1767 * Target descriptions can now describe target-specific registers,
1768 for architectures which have implemented the support (currently
1769 only ARM, M68K, and MIPS).
1771 * GDB and the GDB remote stub, gdbserver, now support the XScale
1774 * The GDB remote stub, gdbserver, has been updated to support
1775 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1776 has been rewritten to use the standard GDB remote protocol.
1778 * GDB can now step into C++ functions which are called through thunks.
1780 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1782 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1783 layout. It also supports a TextSeg= and DataSeg= response when only
1784 segment base addresses (rather than offsets) are available.
1786 * The /i format now outputs any trailing branch delay slot instructions
1787 immediately following the last instruction within the count specified.
1789 * The GDB remote protocol "T" stop reply packet now supports a
1790 "library" response. Combined with the new "qXfer:libraries:read"
1791 packet, this response allows GDB to debug shared libraries on targets
1792 where the operating system manages the list of loaded libraries (e.g.
1793 Windows and SymbianOS).
1795 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1796 (DLLs) on Windows and Windows CE targets.
1798 * GDB now supports a faster verification that a .debug file matches its binary
1799 according to its build-id signature, if the signature is present.
1805 Enable or disable hardware flow control (RTS/CTS) on the serial port
1806 when debugging using remote targets.
1808 set mem inaccessible-by-default
1809 show mem inaccessible-by-default
1810 If the target supplies a memory map, for instance via the remote
1811 protocol's "qXfer:memory-map:read" packet, setting this variable
1812 prevents GDB from accessing memory outside the memory map. This
1813 is useful for targets with memory mapped registers or which react
1814 badly to accesses of unmapped address space.
1816 set breakpoint auto-hw
1817 show breakpoint auto-hw
1818 If the target supplies a memory map, for instance via the remote
1819 protocol's "qXfer:memory-map:read" packet, setting this variable
1820 lets GDB use hardware breakpoints automatically for memory regions
1821 where it can not use software breakpoints. This covers both the
1822 "break" command and internal breakpoints used for other commands
1823 including "next" and "finish".
1826 catch exception unhandled
1827 Stop the program execution when Ada exceptions are raised.
1830 Stop the program execution when an Ada assertion failed.
1834 Set an alternate system root for target files. This is a more
1835 general version of "set solib-absolute-prefix", which is now
1836 an alias to "set sysroot".
1839 Provide extended SPU facility status information. This set of
1840 commands is available only when debugging the Cell/B.E. SPU
1843 * New native configurations
1845 OpenBSD/sh sh*-*openbsd*
1848 unset tdesc filename
1850 Use the specified local file as an XML target description, and do
1851 not query the target for its built-in description.
1855 OpenBSD/sh sh*-*-openbsd*
1856 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
1857 Toshiba Media Processor mep-elf
1859 * New remote packets
1862 Ignore the specified signals; pass them directly to the debugged program
1863 without stopping other threads or reporting them to GDB.
1865 qXfer:features:read:
1866 Read an XML target description from the target, which describes its
1871 Read or write contents of an spufs file on the target system. These
1872 packets are available only on the Cell/B.E. SPU architecture.
1874 qXfer:libraries:read:
1875 Report the loaded shared libraries. Combined with new "T" packet
1876 response, this packet allows GDB to debug shared libraries on
1877 targets where the operating system manages the list of loaded
1878 libraries (e.g. Windows and SymbianOS).
1882 Support for these obsolete configurations has been removed.
1890 i[34567]86-*-lynxos*
1891 i[34567]86-*-netware*
1892 i[34567]86-*-sco3.2v5*
1893 i[34567]86-*-sco3.2v4*
1895 i[34567]86-*-sysv4.2*
1898 i[34567]86-*-unixware2*
1899 i[34567]86-*-unixware*
1908 * Other removed features
1915 Various m68k-only ROM monitors.
1922 Various Renesas ROM monitors and debugging interfaces for SH and
1927 Support for a Macraigor serial interface to on-chip debugging.
1928 GDB does not directly support the newer parallel or USB
1933 A debug information format. The predecessor to DWARF 2 and
1934 DWARF 3, which are still supported.
1936 Support for the HP aCC compiler on HP-UX/PA-RISC
1938 SOM-encapsulated symbolic debugging information, automatic
1939 invocation of pxdb, and the aCC custom C++ ABI. This does not
1940 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
1941 with aCC can still be debugged on an assembly level.
1943 MIPS ".pdr" sections
1945 A MIPS-specific format used to describe stack frame layout
1946 in debugging information.
1950 GDB could work with an older version of Guile to debug
1951 the interpreter and Scheme programs running in it.
1953 set mips stack-arg-size
1954 set mips saved-gpreg-size
1956 Use "set mips abi" to control parameter passing for MIPS.
1958 *** Changes in GDB 6.6
1963 Cell Broadband Engine SPU spu-elf
1965 * GDB can now be configured as a cross-debugger targeting native Windows
1966 (mingw32) or Cygwin. It can communicate with a remote debugging stub
1967 running on a Windows system over TCP/IP to debug Windows programs.
1969 * The GDB remote stub, gdbserver, has been updated to support Windows and
1970 Cygwin debugging. Both single-threaded and multi-threaded programs are
1973 * The "set trust-readonly-sections" command works again. This command was
1974 broken in GDB 6.3, 6.4, and 6.5.
1976 * The "load" command now supports writing to flash memory, if the remote
1977 stub provides the required support.
1979 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
1980 longer requires symbolic debug information (e.g. DWARF-2).
1985 unset substitute-path
1986 show substitute-path
1987 Manage a list of substitution rules that GDB uses to rewrite the name
1988 of the directories where the sources are located. This can be useful
1989 for instance when the sources were moved to a different location
1990 between compilation and debugging.
1994 Print each CLI command as it is executed. Each command is prefixed with
1995 a number of `+' symbols representing the nesting depth.
1996 The source command now has a `-v' option to enable the same feature.
2000 The ARM Demon monitor support (RDP protocol, "target rdp").
2002 Kernel Object Display, an embedded debugging feature which only worked with
2003 an obsolete version of Cisco IOS.
2005 The 'set download-write-size' and 'show download-write-size' commands.
2007 * New remote packets
2010 Tell a stub about GDB client features, and request remote target features.
2011 The first feature implemented is PacketSize, which allows the target to
2012 specify the size of packets it can handle - to minimize the number of
2013 packets required and improve performance when connected to a remote
2017 Fetch an OS auxilliary vector from the remote stub. This packet is a
2018 more efficient replacement for qPart:auxv:read.
2020 qXfer:memory-map:read:
2021 Fetch a memory map from the remote stub, including information about
2022 RAM, ROM, and flash memory devices.
2027 Erase and program a flash memory device.
2029 * Removed remote packets
2032 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2033 used it, and only gdbserver implemented it.
2035 *** Changes in GDB 6.5
2039 Renesas M32C/M16C m32c-elf
2041 Morpho Technologies ms1 ms1-elf
2045 init-if-undefined Initialize a convenience variable, but
2046 only if it doesn't already have a value.
2048 The following commands are presently only implemented for native GNU/Linux:
2050 checkpoint Save a snapshot of the program state.
2052 restart <n> Return the program state to a
2053 previously saved state.
2055 info checkpoints List currently saved checkpoints.
2057 delete-checkpoint <n> Delete a previously saved checkpoint.
2059 set|show detach-on-fork Tell gdb whether to detach from a newly
2060 forked process, or to keep debugging it.
2062 info forks List forks of the user program that
2063 are available to be debugged.
2065 fork <n> Switch to debugging one of several
2066 forks of the user program that are
2067 available to be debugged.
2069 delete-fork <n> Delete a fork from the list of forks
2070 that are available to be debugged (and
2071 kill the forked process).
2073 detach-fork <n> Delete a fork from the list of forks
2074 that are available to be debugged (and
2075 allow the process to continue).
2079 Morpho Technologies ms2 ms1-elf
2081 * Improved Windows host support
2083 GDB now builds as a cross debugger hosted on i686-mingw32, including
2084 native console support, and remote communications using either
2085 network sockets or serial ports.
2087 * Improved Modula-2 language support
2089 GDB can now print most types in the Modula-2 syntax. This includes:
2090 basic types, set types, record types, enumerated types, range types,
2091 pointer types and ARRAY types. Procedure var parameters are correctly
2092 printed and hexadecimal addresses and character constants are also
2093 written in the Modula-2 syntax. Best results can be obtained by using
2094 GNU Modula-2 together with the -gdwarf-2 command line option.
2098 The ARM rdi-share module.
2100 The Netware NLM debug server.
2102 *** Changes in GDB 6.4
2104 * New native configurations
2106 OpenBSD/arm arm*-*-openbsd*
2107 OpenBSD/mips64 mips64-*-openbsd*
2111 Morpho Technologies ms1 ms1-elf
2113 * New command line options
2115 --batch-silent As for --batch, but totally silent.
2116 --return-child-result The debugger will exist with the same value
2117 the child (debugged) program exited with.
2118 --eval-command COMMAND, -ex COMMAND
2119 Execute a single GDB CLI command. This may be
2120 specified multiple times and in conjunction
2121 with the --command (-x) option.
2123 * Deprecated commands removed
2125 The following commands, that were deprecated in 2000, have been
2129 set|show arm disassembly-flavor set|show arm disassembler
2130 othernames set arm disassembler
2131 set|show remotedebug set|show debug remote
2132 set|show archdebug set|show debug arch
2133 set|show eventdebug set|show debug event
2136 * New BSD user-level threads support
2138 It is now possible to debug programs using the user-level threads
2139 library on OpenBSD and FreeBSD. Currently supported (target)
2142 FreeBSD/amd64 x86_64-*-freebsd*
2143 FreeBSD/i386 i386-*-freebsd*
2144 OpenBSD/i386 i386-*-openbsd*
2146 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2147 are not yet supported.
2149 * New support for Matsushita MN10300 w/sim added
2150 (Work in progress). mn10300-elf.
2152 * REMOVED configurations and files
2154 VxWorks and the XDR protocol *-*-vxworks
2155 Motorola MCORE mcore-*-*
2156 National Semiconductor NS32000 ns32k-*-*
2158 * New "set print array-indexes" command
2160 After turning this setting "on", GDB prints the index of each element
2161 when displaying arrays. The default is "off" to preserve the previous
2164 * VAX floating point support
2166 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2168 * User-defined command support
2170 In addition to using $arg0..$arg9 for argument passing, it is now possible
2171 to use $argc to determine now many arguments have been passed. See the
2172 section on user-defined commands in the user manual for more information.
2174 *** Changes in GDB 6.3:
2176 * New command line option
2178 GDB now accepts -l followed by a number to set the timeout for remote
2181 * GDB works with GCC -feliminate-dwarf2-dups
2183 GDB now supports a more compact representation of DWARF-2 debug
2184 information using DW_FORM_ref_addr references. These are produced
2185 by GCC with the option -feliminate-dwarf2-dups and also by some
2186 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2187 to use -feliminate-dwarf2-dups.
2189 * Internationalization
2191 When supported by the host system, GDB will be built with
2192 internationalization (libintl). The task of marking up the sources is
2193 continued, we're looking forward to our first translation.
2197 Initial support for debugging programs compiled with the GNAT
2198 implementation of the Ada programming language has been integrated
2199 into GDB. In this release, support is limited to expression evaluation.
2201 * New native configurations
2203 GNU/Linux/m32r m32r-*-linux-gnu
2207 GDB's remote protocol now includes support for the 'p' packet. This
2208 packet is used to fetch individual registers from a remote inferior.
2210 * END-OF-LIFE registers[] compatibility module
2212 GDB's internal register infrastructure has been completely rewritten.
2213 The new infrastructure making possible the implementation of key new
2214 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2217 GDB 6.3 will be the last release to include the the registers[]
2218 compatibility module that allowed out-of-date configurations to
2219 continue to work. This change directly impacts the following
2229 powerpc bdm protocol
2231 Unless there is activity to revive these configurations, they will be
2232 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2234 * OBSOLETE configurations and files
2236 Configurations that have been declared obsolete in this release have
2237 been commented out. Unless there is activity to revive these
2238 configurations, the next release of GDB will have their sources
2239 permanently REMOVED.
2248 *** Changes in GDB 6.2.1:
2250 * MIPS `break main; run' gave an heuristic-fence-post warning
2252 When attempting to run even a simple program, a warning about
2253 heuristic-fence-post being hit would be reported. This problem has
2256 * MIPS IRIX 'long double' crashed GDB
2258 When examining a long double variable, GDB would get a segmentation
2259 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2260 IRIX long double values).
2264 A bug in the VAX stack code was causing problems with the "next"
2265 command. This problem has been fixed.
2267 *** Changes in GDB 6.2:
2269 * Fix for ``many threads''
2271 On GNU/Linux systems that use the NPTL threads library, a program
2272 rapidly creating and deleting threads would confuse GDB leading to the
2275 ptrace: No such process.
2276 thread_db_get_info: cannot get thread info: generic error
2278 This problem has been fixed.
2280 * "-async" and "-noasync" options removed.
2282 Support for the broken "-noasync" option has been removed (it caused
2285 * New ``start'' command.
2287 This command runs the program until the begining of the main procedure.
2289 * New BSD Kernel Data Access Library (libkvm) interface
2291 Using ``target kvm'' it is now possible to debug kernel core dumps and
2292 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2293 platforms. Currently supported (native-only) configurations are:
2295 FreeBSD/amd64 x86_64-*-freebsd*
2296 FreeBSD/i386 i?86-*-freebsd*
2297 NetBSD/i386 i?86-*-netbsd*
2298 NetBSD/m68k m68*-*-netbsd*
2299 NetBSD/sparc sparc-*-netbsd*
2300 OpenBSD/amd64 x86_64-*-openbsd*
2301 OpenBSD/i386 i?86-*-openbsd*
2302 OpenBSD/m68k m68*-openbsd*
2303 OpenBSD/sparc sparc-*-openbsd*
2305 * Signal trampoline code overhauled
2307 Many generic problems with GDB's signal handling code have been fixed.
2308 These include: backtraces through non-contiguous stacks; recognition
2309 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2310 call; backtrace through a signal trampoline; step into and out of
2311 signal handlers; and single-stepping in the signal trampoline.
2313 Please note that kernel bugs are a limiting factor here. These
2314 features have been shown to work on an s390 GNU/Linux system that
2315 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2317 * Cygwin support for DWARF 2 added.
2319 * New native configurations
2321 GNU/Linux/hppa hppa*-*-linux*
2322 OpenBSD/hppa hppa*-*-openbsd*
2323 OpenBSD/m68k m68*-*-openbsd*
2324 OpenBSD/m88k m88*-*-openbsd*
2325 OpenBSD/powerpc powerpc-*-openbsd*
2326 NetBSD/vax vax-*-netbsd*
2327 OpenBSD/vax vax-*-openbsd*
2329 * END-OF-LIFE frame compatibility module
2331 GDB's internal frame infrastructure has been completely rewritten.
2332 The new infrastructure making it possible to support key new features
2333 including DWARF 2 Call Frame Information. To aid in the task of
2334 migrating old configurations to this new infrastructure, a
2335 compatibility module, that allowed old configurations to continue to
2336 work, was also included.
2338 GDB 6.2 will be the last release to include this frame compatibility
2339 module. This change directly impacts the following configurations:
2349 Unless there is activity to revive these configurations, they will be
2350 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2352 * REMOVED configurations and files
2354 Sun 3, running SunOS 3 m68*-*-sunos3*
2355 Sun 3, running SunOS 4 m68*-*-sunos4*
2356 Sun 2, running SunOS 3 m68000-*-sunos3*
2357 Sun 2, running SunOS 4 m68000-*-sunos4*
2358 Motorola 680x0 running LynxOS m68*-*-lynxos*
2359 AT&T 3b1/Unix pc m68*-att-*
2360 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2361 decstation mips-dec-* mips-little-*
2362 riscos mips-*-riscos* mips-*-sysv*
2363 sonymips mips-sony-*
2364 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2366 *** Changes in GDB 6.1.1:
2368 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2370 The TUI (Text-mode User Interface) is now built as part of a default
2371 GDB configuration. It is enabled by either selecting the TUI with the
2372 command line option "-i=tui" or by running the separate "gdbtui"
2373 program. For more information on the TUI, see the manual "Debugging
2376 * Pending breakpoint support (also included in GDB 6.1)
2378 Support has been added to allow you to specify breakpoints in shared
2379 libraries that have not yet been loaded. If a breakpoint location
2380 cannot be found, and the "breakpoint pending" option is set to auto,
2381 GDB queries you if you wish to make the breakpoint pending on a future
2382 shared-library load. If and when GDB resolves the breakpoint symbol,
2383 the pending breakpoint is removed as one or more regular breakpoints
2386 Pending breakpoints are very useful for GCJ Java debugging.
2388 * Fixed ISO-C build problems
2390 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2391 non ISO-C code that stopped them being built using a more strict ISO-C
2392 compiler (e.g., IBM's C compiler).
2394 * Fixed build problem on IRIX 5
2396 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2397 wasn't able to compile compile on an IRIX 5 system.
2399 * Added execute permission to gdb/gdbserver/configure
2401 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2402 permission. This bug would cause configure to fail on a number of
2403 systems (Solaris, IRIX). Ref: server/519.
2405 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2407 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2408 has been updated to use constant array sizes.
2410 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2412 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2413 its generated DWARF Call Frame Info. This encoding was causing GDB to
2414 panic, that panic has been fixed. Ref: gdb/1628.
2416 * Fixed a problem when examining parameters in shared library code.
2418 When examining parameters in optimized shared library code generated
2419 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2420 not available''. GDB now correctly displays the variable's value.
2422 *** Changes in GDB 6.1:
2424 * Removed --with-mmalloc
2426 Support for the mmalloc memory manager has been removed, as it
2427 conflicted with the internal gdb byte cache.
2429 * Changes in AMD64 configurations
2431 The AMD64 target now includes the %cs and %ss registers. As a result
2432 the AMD64 remote protocol has changed; this affects the floating-point
2433 and SSE registers. If you rely on those registers for your debugging,
2434 you should upgrade gdbserver on the remote side.
2436 * Revised SPARC target
2438 The SPARC target has been completely revised, incorporating the
2439 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2440 support for LynxOS and SunOS 4 has been dropped. Calling functions
2441 from within GDB on operating systems with a non-executable stack
2442 (Solaris, OpenBSD) now works.
2446 GDB has a new C++ demangler which does a better job on the mangled
2447 names generated by current versions of g++. It also runs faster, so
2448 with this and other changes gdb should now start faster on large C++
2451 * DWARF 2 Location Expressions
2453 GDB support for location expressions has been extended to support function
2454 arguments and frame bases. Older versions of GDB could crash when they
2457 * C++ nested types and namespaces
2459 GDB's support for nested types and namespaces in C++ has been
2460 improved, especially if you use the DWARF 2 debugging format. (This
2461 is the default for recent versions of GCC on most platforms.)
2462 Specifically, if you have a class "Inner" defined within a class or
2463 namespace "Outer", then GDB realizes that the class's name is
2464 "Outer::Inner", not simply "Inner". This should greatly reduce the
2465 frequency of complaints about not finding RTTI symbols. In addition,
2466 if you are stopped at inside of a function defined within a namespace,
2467 GDB modifies its name lookup accordingly.
2469 * New native configurations
2471 NetBSD/amd64 x86_64-*-netbsd*
2472 OpenBSD/amd64 x86_64-*-openbsd*
2473 OpenBSD/alpha alpha*-*-openbsd*
2474 OpenBSD/sparc sparc-*-openbsd*
2475 OpenBSD/sparc64 sparc64-*-openbsd*
2477 * New debugging protocols
2479 M32R with SDI protocol m32r-*-elf*
2481 * "set prompt-escape-char" command deleted.
2483 The command "set prompt-escape-char" has been deleted. This command,
2484 and its very obscure effet on GDB's prompt, was never documented,
2485 tested, nor mentioned in the NEWS file.
2487 * OBSOLETE configurations and files
2489 Configurations that have been declared obsolete in this release have
2490 been commented out. Unless there is activity to revive these
2491 configurations, the next release of GDB will have their sources
2492 permanently REMOVED.
2494 Sun 3, running SunOS 3 m68*-*-sunos3*
2495 Sun 3, running SunOS 4 m68*-*-sunos4*
2496 Sun 2, running SunOS 3 m68000-*-sunos3*
2497 Sun 2, running SunOS 4 m68000-*-sunos4*
2498 Motorola 680x0 running LynxOS m68*-*-lynxos*
2499 AT&T 3b1/Unix pc m68*-att-*
2500 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2501 decstation mips-dec-* mips-little-*
2502 riscos mips-*-riscos* mips-*-sysv*
2503 sonymips mips-sony-*
2504 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2506 * REMOVED configurations and files
2508 SGI Irix-4.x mips-sgi-irix4 or iris4
2509 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2510 Z8000 simulator z8k-zilog-none or z8ksim
2511 Matsushita MN10200 w/simulator mn10200-*-*
2512 H8/500 simulator h8500-hitachi-hms or h8500hms
2513 HP/PA running BSD hppa*-*-bsd*
2514 HP/PA running OSF/1 hppa*-*-osf*
2515 HP/PA Pro target hppa*-*-pro*
2516 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2517 386BSD i[3456]86-*-bsd*
2518 Sequent family i[3456]86-sequent-sysv4*
2519 i[3456]86-sequent-sysv*
2520 i[3456]86-sequent-bsd*
2521 SPARC running LynxOS sparc-*-lynxos*
2522 SPARC running SunOS 4 sparc-*-sunos4*
2523 Tsqware Sparclet sparclet-*-*
2524 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2526 *** Changes in GDB 6.0:
2530 Support for debugging the Objective-C programming language has been
2531 integrated into GDB.
2533 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2535 DWARF 2's Call Frame Information makes available compiler generated
2536 information that more exactly describes the program's run-time stack.
2537 By using this information, GDB is able to provide more robust stack
2540 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2541 have been updated to use a new backtrace mechanism which includes
2542 DWARF 2 CFI support.
2546 GDB's remote protocol has been extended to include support for hosted
2547 file I/O (where the remote target uses GDB's file system). See GDB's
2548 remote protocol documentation for details.
2550 * All targets using the new architecture framework.
2552 All of GDB's targets have been updated to use the new internal
2553 architecture framework. The way is now open for future GDB releases
2554 to include cross-architecture native debugging support (i386 on amd64,
2557 * GNU/Linux's Thread Local Storage (TLS)
2559 GDB now includes support for for the GNU/Linux implementation of
2560 per-thread variables.
2562 * GNU/Linux's Native POSIX Thread Library (NPTL)
2564 GDB's thread code has been updated to work with either the new
2565 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2567 * Separate debug info.
2569 GDB, in conjunction with BINUTILS, now supports a mechanism for
2570 automatically loading debug information from a separate file. Instead
2571 of shipping full debug and non-debug versions of system libraries,
2572 system integrators can now instead ship just the stripped libraries
2573 and optional debug files.
2575 * DWARF 2 Location Expressions
2577 DWARF 2 Location Expressions allow the compiler to more completely
2578 describe the location of variables (even in optimized code) to the
2581 GDB now includes preliminary support for location expressions (support
2582 for DW_OP_piece is still missing).
2586 A number of long standing bugs that caused GDB to die while starting a
2587 Java application have been fixed. GDB's Java support is now
2588 considered "useable".
2590 * GNU/Linux support for fork, vfork, and exec.
2592 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2593 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2596 * GDB supports logging output to a file
2598 There are two new commands, "set logging" and "show logging", which can be
2599 used to capture GDB's output to a file.
2601 * The meaning of "detach" has changed for gdbserver
2603 The "detach" command will now resume the application, as documented. To
2604 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2607 * d10v, m68hc11 `regs' command deprecated
2609 The `info registers' command has been updated so that it displays the
2610 registers using a format identical to the old `regs' command.
2614 A new command, "maint set profile on/off", has been added. This command can
2615 be used to enable or disable profiling while running GDB, to profile a
2616 session or a set of commands. In addition there is a new configure switch,
2617 "--enable-profiling", which will cause GDB to be compiled with profiling
2618 data, for more informative profiling results.
2620 * Default MI syntax changed to "mi2".
2622 The default MI (machine interface) syntax, enabled by the command line
2623 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2624 "mi1", can be enabled by specifying the option "-i=mi1".
2626 Support for the original "mi0" syntax (included in GDB 5.0) has been
2629 Fix for gdb/192: removed extraneous space when displaying frame level.
2630 Fix for gdb/672: update changelist is now output in mi list format.
2631 Fix for gdb/702: a -var-assign that updates the value now shows up
2632 in a subsequent -var-update.
2634 * New native configurations.
2636 FreeBSD/amd64 x86_64-*-freebsd*
2638 * Multi-arched targets.
2640 HP/PA HPUX11 hppa*-*-hpux*
2641 Renesas M32R/D w/simulator m32r-*-elf*
2643 * OBSOLETE configurations and files
2645 Configurations that have been declared obsolete in this release have
2646 been commented out. Unless there is activity to revive these
2647 configurations, the next release of GDB will have their sources
2648 permanently REMOVED.
2650 Z8000 simulator z8k-zilog-none or z8ksim
2651 Matsushita MN10200 w/simulator mn10200-*-*
2652 H8/500 simulator h8500-hitachi-hms or h8500hms
2653 HP/PA running BSD hppa*-*-bsd*
2654 HP/PA running OSF/1 hppa*-*-osf*
2655 HP/PA Pro target hppa*-*-pro*
2656 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2657 Sequent family i[3456]86-sequent-sysv4*
2658 i[3456]86-sequent-sysv*
2659 i[3456]86-sequent-bsd*
2660 Tsqware Sparclet sparclet-*-*
2661 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2663 * REMOVED configurations and files
2666 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2667 IBM AIX PS/2 i[3456]86-*-aix
2668 i386 running Mach 3.0 i[3456]86-*-mach3*
2669 i386 running Mach i[3456]86-*-mach*
2670 i386 running OSF/1 i[3456]86-*osf1mk*
2671 HP/Apollo 68k Family m68*-apollo*-sysv*,
2673 m68*-hp-bsd*, m68*-hp-hpux*
2674 Argonaut Risc Chip (ARC) arc-*-*
2675 Mitsubishi D30V d30v-*-*
2676 Fujitsu FR30 fr30-*-elf*
2677 OS/9000 i[34]86-*-os9k
2678 I960 with MON960 i960-*-coff
2680 * MIPS $fp behavior changed
2682 The convenience variable $fp, for the MIPS, now consistently returns
2683 the address of the current frame's base. Previously, depending on the
2684 context, $fp could refer to either $sp or the current frame's base
2685 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2686 The GNU Source-Level Debugger''.
2688 *** Changes in GDB 5.3:
2690 * GNU/Linux shared library multi-threaded performance improved.
2692 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2693 `/proc', in preference to `ptrace' for memory reads. This may result
2694 in an improvement in the start-up time of multi-threaded, shared
2695 library applications when run under GDB. One GDB user writes: ``loads
2696 shared libs like mad''.
2698 * ``gdbserver'' now supports multi-threaded applications on some targets
2700 Support for debugging multi-threaded applications which use
2701 the GNU/Linux LinuxThreads package has been added for
2702 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2703 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2705 * GDB now supports C/C++ preprocessor macros.
2707 GDB now expands preprocessor macro invocations in C/C++ expressions,
2708 and provides various commands for showing macro definitions and how
2711 The new command `macro expand EXPRESSION' expands any macro
2712 invocations in expression, and shows the result.
2714 The new command `show macro MACRO-NAME' shows the definition of the
2715 macro named MACRO-NAME, and where it was defined.
2717 Most compilers don't include information about macros in the debugging
2718 information by default. In GCC 3.1, for example, you need to compile
2719 your program with the options `-gdwarf-2 -g3'. If the macro
2720 information is present in the executable, GDB will read it.
2722 * Multi-arched targets.
2724 DEC Alpha (partial) alpha*-*-*
2725 DEC VAX (partial) vax-*-*
2727 National Semiconductor NS32000 (partial) ns32k-*-*
2728 Motorola 68000 (partial) m68k-*-*
2729 Motorola MCORE mcore-*-*
2733 Fujitsu FRV architecture added by Red Hat frv*-*-*
2736 * New native configurations
2738 Alpha NetBSD alpha*-*-netbsd*
2739 SH NetBSD sh*-*-netbsdelf*
2740 MIPS NetBSD mips*-*-netbsd*
2741 UltraSPARC NetBSD sparc64-*-netbsd*
2743 * OBSOLETE configurations and files
2745 Configurations that have been declared obsolete in this release have
2746 been commented out. Unless there is activity to revive these
2747 configurations, the next release of GDB will have their sources
2748 permanently REMOVED.
2750 Mitsubishi D30V d30v-*-*
2751 OS/9000 i[34]86-*-os9k
2752 IBM AIX PS/2 i[3456]86-*-aix
2753 Fujitsu FR30 fr30-*-elf*
2754 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2755 Argonaut Risc Chip (ARC) arc-*-*
2756 i386 running Mach 3.0 i[3456]86-*-mach3*
2757 i386 running Mach i[3456]86-*-mach*
2758 i386 running OSF/1 i[3456]86-*osf1mk*
2759 HP/Apollo 68k Family m68*-apollo*-sysv*,
2761 m68*-hp-bsd*, m68*-hp-hpux*
2762 I960 with MON960 i960-*-coff
2764 * OBSOLETE languages
2766 CHILL, a Pascal like language used by telecommunications companies.
2768 * REMOVED configurations and files
2770 AMD 29k family via UDI a29k-amd-udi, udi29k
2771 A29K VxWorks a29k-*-vxworks
2772 AMD 29000 embedded, using EBMON a29k-none-none
2773 AMD 29000 embedded with COFF a29k-none-coff
2774 AMD 29000 embedded with a.out a29k-none-aout
2776 testsuite/gdb.hp/gdb.threads-hp/ directory
2778 * New command "set max-user-call-depth <nnn>"
2780 This command allows the user to limit the call depth of user-defined
2781 commands. The default is 1024.
2783 * Changes in FreeBSD/i386 native debugging.
2785 Support for the "generate-core-file" has been added.
2787 * New commands "dump", "append", and "restore".
2789 These commands allow data to be copied from target memory
2790 to a bfd-format or binary file (dump and append), and back
2791 from a file into memory (restore).
2793 * Improved "next/step" support on multi-processor Alpha Tru64.
2795 The previous single-step mechanism could cause unpredictable problems,
2796 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2797 of a software single-step mechanism prevents this.
2799 *** Changes in GDB 5.2.1:
2807 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2808 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2809 Fix, by Joel Brobecker imported from mainline.
2811 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2812 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2813 Fix, by Fred Fish, imported from mainline.
2815 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2816 Surprisingly enough, it works now.
2817 By Michal Ludvig, imported from mainline.
2819 i386 hardware watchpoint support:
2820 avoid misses on second run for some targets.
2821 By Pierre Muller, imported from mainline.
2823 *** Changes in GDB 5.2:
2825 * New command "set trust-readonly-sections on[off]".
2827 This command is a hint that tells gdb that read-only sections
2828 really are read-only (ie. that their contents will not change).
2829 In this mode, gdb will go to the object file rather than the
2830 target to read memory from read-only sections (such as ".text").
2831 This can be a significant performance improvement on some
2832 (notably embedded) targets.
2834 * New command "generate-core-file" (or "gcore").
2836 This new gdb command allows the user to drop a core file of the child
2837 process state at any time. So far it's been implemented only for
2838 GNU/Linux and Solaris, but should be relatively easily ported to other
2839 hosts. Argument is core file name (defaults to core.<pid>).
2841 * New command line option
2843 GDB now accepts --pid or -p followed by a process id.
2845 * Change in command line behavior -- corefiles vs. process ids.
2847 There is a subtle behavior in the way in which GDB handles
2848 command line arguments. The first non-flag argument is always
2849 a program to debug, but the second non-flag argument may either
2850 be a corefile or a process id. Previously, GDB would attempt to
2851 open the second argument as a corefile, and if that failed, would
2852 issue a superfluous error message and then attempt to attach it as
2853 a process. Now, if the second argument begins with a non-digit,
2854 it will be treated as a corefile. If it begins with a digit,
2855 GDB will attempt to attach it as a process, and if no such process
2856 is found, will then attempt to open it as a corefile.
2858 * Changes in ARM configurations.
2860 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
2861 configuration is fully multi-arch.
2863 * New native configurations
2865 ARM NetBSD arm*-*-netbsd*
2866 x86 OpenBSD i[3456]86-*-openbsd*
2867 AMD x86-64 running GNU/Linux x86_64-*-linux-*
2868 Sparc64 running FreeBSD sparc64-*-freebsd*
2872 Sanyo XStormy16 xstormy16-elf
2874 * OBSOLETE configurations and files
2876 Configurations that have been declared obsolete in this release have
2877 been commented out. Unless there is activity to revive these
2878 configurations, the next release of GDB will have their sources
2879 permanently REMOVED.
2881 AMD 29k family via UDI a29k-amd-udi, udi29k
2882 A29K VxWorks a29k-*-vxworks
2883 AMD 29000 embedded, using EBMON a29k-none-none
2884 AMD 29000 embedded with COFF a29k-none-coff
2885 AMD 29000 embedded with a.out a29k-none-aout
2887 testsuite/gdb.hp/gdb.threads-hp/ directory
2889 * REMOVED configurations and files
2891 TI TMS320C80 tic80-*-*
2893 PowerPC Solaris powerpcle-*-solaris*
2894 PowerPC Windows NT powerpcle-*-cygwin32
2895 PowerPC Netware powerpc-*-netware*
2896 Harris/CXUX m88k m88*-harris-cxux*
2897 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2898 ns32k-utek-sysv* ns32k-utek-*
2899 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2900 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2901 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2902 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2903 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
2905 * Changes to command line processing
2907 The new `--args' feature can be used to specify command-line arguments
2908 for the inferior from gdb's command line.
2910 * Changes to key bindings
2912 There is a new `operate-and-get-next' function bound to `C-o'.
2914 *** Changes in GDB 5.1.1
2916 Fix compile problem on DJGPP.
2918 Fix a problem with floating-point registers on the i386 being
2921 Fix to stop GDB crashing on .debug_str debug info.
2923 Numerous documentation fixes.
2925 Numerous testsuite fixes.
2927 *** Changes in GDB 5.1:
2929 * New native configurations
2931 Alpha FreeBSD alpha*-*-freebsd*
2932 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
2933 MIPS GNU/Linux mips*-*-linux*
2934 MIPS SGI Irix 6.x mips*-sgi-irix6*
2935 ia64 AIX ia64-*-aix*
2936 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
2940 Motorola 68HC11 and 68HC12 m68hc11-elf
2942 UltraSparc running GNU/Linux sparc64-*-linux*
2944 * OBSOLETE configurations and files
2946 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
2947 Harris/CXUX m88k m88*-harris-cxux*
2948 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
2949 ns32k-utek-sysv* ns32k-utek-*
2950 TI TMS320C80 tic80-*-*
2952 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
2953 PowerPC Solaris powerpcle-*-solaris*
2954 PowerPC Windows NT powerpcle-*-cygwin32
2955 PowerPC Netware powerpc-*-netware*
2956 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
2957 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
2958 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
2959 Apple Macintosh (MPW) host N/A
2961 stuff.c (Program to stuff files into a specially prepared space in kdb)
2962 kdb-start.c (Main loop for the standalone kernel debugger)
2964 Configurations that have been declared obsolete in this release have
2965 been commented out. Unless there is activity to revive these
2966 configurations, the next release of GDB will have their sources
2967 permanently REMOVED.
2969 * REMOVED configurations and files
2971 Altos 3068 m68*-altos-*
2972 Convex c1-*-*, c2-*-*
2974 ARM RISCix arm-*-* (as host)
2978 * GDB has been converted to ISO C.
2980 GDB's source code has been converted to ISO C. In particular, the
2981 sources are fully protoized, and rely on standard headers being
2986 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
2988 * The MI enabled by default.
2990 The new machine oriented interface (MI) introduced in GDB 5.0 has been
2991 revised and enabled by default. Packages which use GDB as a debugging
2992 engine behind a UI or another front end are encouraged to switch to
2993 using the GDB/MI interface, instead of the old annotations interface
2994 which is now deprecated.
2996 * Support for debugging Pascal programs.
2998 GDB now includes support for debugging Pascal programs. The following
2999 main features are supported:
3001 - Pascal-specific data types such as sets;
3003 - automatic recognition of Pascal sources based on file-name
3006 - Pascal-style display of data types, variables, and functions;
3008 - a Pascal expression parser.
3010 However, some important features are not yet supported.
3012 - Pascal string operations are not supported at all;
3014 - there are some problems with boolean types;
3016 - Pascal type hexadecimal constants are not supported
3017 because they conflict with the internal variables format;
3019 - support for Pascal objects and classes is not full yet;
3021 - unlike Pascal, GDB is case-sensitive for symbol names.
3023 * Changes in completion.
3025 Commands such as `shell', `run' and `set args', which pass arguments
3026 to inferior programs, now complete on file names, similar to what
3027 users expect at the shell prompt.
3029 Commands which accept locations, such as `disassemble', `print',
3030 `breakpoint', `until', etc. now complete on filenames as well as
3031 program symbols. Thus, if you type "break foob TAB", and the source
3032 files linked into the programs include `foobar.c', that file name will
3033 be one of the candidates for completion. However, file names are not
3034 considered for completion after you typed a colon that delimits a file
3035 name from a name of a function in that file, as in "break foo.c:bar".
3037 `set demangle-style' completes on available demangling styles.
3039 * New platform-independent commands:
3041 It is now possible to define a post-hook for a command as well as a
3042 hook that runs before the command. For more details, see the
3043 documentation of `hookpost' in the GDB manual.
3045 * Changes in GNU/Linux native debugging.
3047 Support for debugging multi-threaded programs has been completely
3048 revised for all platforms except m68k and sparc. You can now debug as
3049 many threads as your system allows you to have.
3051 Attach/detach is supported for multi-threaded programs.
3053 Support for SSE registers was added for x86. This doesn't work for
3054 multi-threaded programs though.
3056 * Changes in MIPS configurations.
3058 Multi-arch support is enabled for all MIPS configurations.
3060 GDB can now be built as native debugger on SGI Irix 6.x systems for
3061 debugging n32 executables. (Debugging 64-bit executables is not yet
3064 * Unified support for hardware watchpoints in all x86 configurations.
3066 Most (if not all) native x86 configurations support hardware-assisted
3067 breakpoints and watchpoints in a unified manner. This support
3068 implements debug register sharing between watchpoints, which allows to
3069 put a virtually infinite number of watchpoints on the same address,
3070 and also supports watching regions up to 16 bytes with several debug
3073 The new maintenance command `maintenance show-debug-regs' toggles
3074 debugging print-outs in functions that insert, remove, and test
3075 watchpoints and hardware breakpoints.
3077 * Changes in the DJGPP native configuration.
3079 New command ``info dos sysinfo'' displays assorted information about
3080 the CPU, OS, memory, and DPMI server.
3082 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3083 display information about segment descriptors stored in GDT, LDT, and
3086 New commands ``info dos pde'' and ``info dos pte'' display entries
3087 from Page Directory and Page Tables (for now works with CWSDPMI only).
3088 New command ``info dos address-pte'' displays the Page Table entry for
3089 a given linear address.
3091 GDB can now pass command lines longer than 126 characters to the
3092 program being debugged (requires an update to the libdbg.a library
3093 which is part of the DJGPP development kit).
3095 DWARF2 debug info is now supported.
3097 It is now possible to `step' and `next' through calls to `longjmp'.
3099 * Changes in documentation.
3101 All GDB documentation was converted to GFDL, the GNU Free
3102 Documentation License.
3104 Tracepoints-related commands are now fully documented in the GDB
3107 TUI, the Text-mode User Interface, is now documented in the manual.
3109 Tracepoints-related commands are now fully documented in the GDB
3112 The "GDB Internals" manual now has an index. It also includes
3113 documentation of `ui_out' functions, GDB coding standards, x86
3114 hardware watchpoints, and memory region attributes.
3116 * GDB's version number moved to ``version.in''
3118 The Makefile variable VERSION has been replaced by the file
3119 ``version.in''. People creating GDB distributions should update the
3120 contents of this file.
3124 GUD support is now a standard part of the EMACS distribution.
3126 *** Changes in GDB 5.0:
3128 * Improved support for debugging FP programs on x86 targets
3130 Unified and much-improved support for debugging floating-point
3131 programs on all x86 targets. In particular, ``info float'' now
3132 displays the FP registers in the same format on all x86 targets, with
3133 greater level of detail.
3135 * Improvements and bugfixes in hardware-assisted watchpoints
3137 It is now possible to watch array elements, struct members, and
3138 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3139 on x86 targets no longer erroneously trigger when the address is
3142 * Improvements in the native DJGPP version of GDB
3144 The distribution now includes all the scripts and auxiliary files
3145 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3146 machines ``out of the box''.
3148 The DJGPP version can now debug programs that use signals. It is
3149 possible to catch signals that happened in the debuggee, deliver
3150 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3151 would kill the program being debugged.) Programs that hook hardware
3152 interrupts (keyboard, timer, etc.) can also be debugged.
3154 It is now possible to debug DJGPP programs that redirect their
3155 standard handles or switch them to raw (as opposed to cooked) mode, or
3156 even close them. The command ``run < foo > bar'' works as expected,
3157 and ``info terminal'' reports useful information about the debuggee's
3158 terminal, including raw/cooked mode, redirection, etc.
3160 The DJGPP version now uses termios functions for console I/O, which
3161 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3164 DOS-style file names with drive letters are now fully supported by
3167 It is now possible to debug DJGPP programs that switch their working
3168 directory. It is also possible to rerun the debuggee any number of
3169 times without restarting GDB; thus, you can use the same setup,
3170 breakpoints, etc. for many debugging sessions.
3172 * New native configurations
3174 ARM GNU/Linux arm*-*-linux*
3175 PowerPC GNU/Linux powerpc-*-linux*
3179 Motorola MCore mcore-*-*
3180 x86 VxWorks i[3456]86-*-vxworks*
3181 PowerPC VxWorks powerpc-*-vxworks*
3182 TI TMS320C80 tic80-*-*
3184 * OBSOLETE configurations
3186 Altos 3068 m68*-altos-*
3187 Convex c1-*-*, c2-*-*
3189 ARM RISCix arm-*-* (as host)
3192 Configurations that have been declared obsolete will be commented out,
3193 but the code will be left in place. If there is no activity to revive
3194 these configurations before the next release of GDB, the sources will
3195 be permanently REMOVED.
3197 * Gould support removed
3199 Support for the Gould PowerNode and NP1 has been removed.
3201 * New features for SVR4
3203 On SVR4 native platforms (such as Solaris), if you attach to a process
3204 without first loading a symbol file, GDB will now attempt to locate and
3205 load symbols from the running process's executable file.
3207 * Many C++ enhancements
3209 C++ support has been greatly improved. Overload resolution now works properly
3210 in almost all cases. RTTI support is on the way.
3212 * Remote targets can connect to a sub-program
3214 A popen(3) style serial-device has been added. This device starts a
3215 sub-process (such as a stand-alone simulator) and then communicates
3216 with that. The sub-program to run is specified using the syntax
3217 ``|<program> <args>'' vis:
3219 (gdb) set remotedebug 1
3220 (gdb) target extended-remote |mn10300-elf-sim program-args
3222 * MIPS 64 remote protocol
3224 A long standing bug in the mips64 remote protocol where by GDB
3225 expected certain 32 bit registers (ex SR) to be transfered as 32
3226 instead of 64 bits has been fixed.
3228 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3229 added to provide backward compatibility with older versions of GDB.
3231 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3233 The command ``set remotebinarydownload'' command has been replaced by
3234 ``set remote X-packet''. Other commands in ``set remote'' family
3235 include ``set remote P-packet''.
3237 * Breakpoint commands accept ranges.
3239 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3240 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3241 ``tracepoint passcount'' also accepts a range of tracepoints.
3243 * ``apropos'' command added.
3245 The ``apropos'' command searches through command names and
3246 documentation strings, printing out matches, making it much easier to
3247 try to find a command that does what you are looking for.
3251 A new machine oriented interface (MI) has been added to GDB. This
3252 interface is designed for debug environments running GDB as a separate
3253 process. This is part of the long term libGDB project. See the
3254 "GDB/MI" chapter of the GDB manual for further information. It can be
3255 enabled by configuring with:
3257 .../configure --enable-gdbmi
3259 *** Changes in GDB-4.18:
3261 * New native configurations
3263 HP-UX 10.20 hppa*-*-hpux10.20
3264 HP-UX 11.x hppa*-*-hpux11.0*
3265 M68K GNU/Linux m68*-*-linux*
3269 Fujitsu FR30 fr30-*-elf*
3270 Intel StrongARM strongarm-*-*
3271 Mitsubishi D30V d30v-*-*
3273 * OBSOLETE configurations
3275 Gould PowerNode, NP1 np1-*-*, pn-*-*
3277 Configurations that have been declared obsolete will be commented out,
3278 but the code will be left in place. If there is no activity to revive
3279 these configurations before the next release of GDB, the sources will
3280 be permanently REMOVED.
3284 As a compatibility experiment, GDB's source files buildsym.h and
3285 buildsym.c have been converted to pure standard C, no longer
3286 containing any K&R compatibility code. We believe that all systems in
3287 use today either come with a standard C compiler, or have a GCC port
3288 available. If this is not true, please report the affected
3289 configuration to bug-gdb@gnu.org immediately. See the README file for
3290 information about getting a standard C compiler if you don't have one
3295 GDB now uses readline 2.2.
3297 * set extension-language
3299 You can now control the mapping between filename extensions and source
3300 languages by using the `set extension-language' command. For instance,
3301 you can ask GDB to treat .c files as C++ by saying
3302 set extension-language .c c++
3303 The command `info extensions' lists all of the recognized extensions
3304 and their associated languages.
3306 * Setting processor type for PowerPC and RS/6000
3308 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3309 you can use the `set processor' command to specify what variant of the
3310 PowerPC family you are debugging. The command
3314 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3315 following PowerPC and RS6000 variants:
3317 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3318 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3320 403GC IBM PowerPC 403GC
3321 505 Motorola PowerPC 505
3322 860 Motorola PowerPC 860 or 850
3323 601 Motorola PowerPC 601
3324 602 Motorola PowerPC 602
3325 603 Motorola/IBM PowerPC 603 or 603e
3326 604 Motorola PowerPC 604 or 604e
3327 750 Motorola/IBM PowerPC 750 or 750
3329 At the moment, this command just tells GDB what to name the
3330 special-purpose processor registers. Since almost all the affected
3331 registers are inaccessible to user-level programs, this command is
3332 only useful for remote debugging in its present form.
3336 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3337 more extensive support for HP-UX. Added features include shared
3338 library support, kernel threads and hardware watchpoints for 11.00,
3339 support for HP's ANSI C and C++ compilers, and a compatibility mode
3340 for xdb and dbx commands.
3344 HP's donation includes the new concept of catchpoints, which is a
3345 generalization of the old catch command. On HP-UX, it is now possible
3346 to catch exec, fork, and vfork, as well as library loading.
3348 This means that the existing catch command has changed; its first
3349 argument now specifies the type of catch to be set up. See the
3350 output of "help catch" for a list of catchpoint types.
3352 * Debugging across forks
3354 On HP-UX, you can choose which process to debug when a fork() happens
3359 HP has donated a curses-based terminal user interface (TUI). To get
3360 it, build with --enable-tui. Although this can be enabled for any
3361 configuration, at present it only works for native HP debugging.
3363 * GDB remote protocol additions
3365 A new protocol packet 'X' that writes binary data is now available.
3366 Default behavior is to try 'X', then drop back to 'M' if the stub
3367 fails to respond. The settable variable `remotebinarydownload'
3368 allows explicit control over the use of 'X'.
3370 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3371 full 64-bit address. The command
3373 set remoteaddresssize 32
3375 can be used to revert to the old behaviour. For existing remote stubs
3376 the change should not be noticed, as the additional address information
3379 In order to assist in debugging stubs, you may use the maintenance
3380 command `packet' to send any text string to the stub. For instance,
3382 maint packet heythere
3384 sends the packet "$heythere#<checksum>". Note that it is very easy to
3385 disrupt a debugging session by sending the wrong packet at the wrong
3388 The compare-sections command allows you to compare section data on the
3389 target to what is in the executable file without uploading or
3390 downloading, by comparing CRC checksums.
3392 * Tracing can collect general expressions
3394 You may now collect general expressions at tracepoints. This requires
3395 further additions to the target-side stub; see tracepoint.c and
3396 doc/agentexpr.texi for further details.
3398 * mask-address variable for Mips
3400 For Mips targets, you may control the zeroing of the upper 32 bits of
3401 a 64-bit address by entering `set mask-address on'. This is mainly
3402 of interest to users of embedded R4xxx and R5xxx processors.
3404 * Higher serial baud rates
3406 GDB's serial code now allows you to specify baud rates 57600, 115200,
3407 230400, and 460800 baud. (Note that your host system may not be able
3408 to achieve all of these rates.)
3412 The i960 configuration now includes an initial implementation of a
3413 builtin simulator, contributed by Jim Wilson.
3416 *** Changes in GDB-4.17:
3418 * New native configurations
3420 Alpha GNU/Linux alpha*-*-linux*
3421 Unixware 2.x i[3456]86-unixware2*
3422 Irix 6.x mips*-sgi-irix6*
3423 PowerPC GNU/Linux powerpc-*-linux*
3424 PowerPC Solaris powerpcle-*-solaris*
3425 Sparc GNU/Linux sparc-*-linux*
3426 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3430 Argonaut Risc Chip (ARC) arc-*-*
3431 Hitachi H8/300S h8300*-*-*
3432 Matsushita MN10200 w/simulator mn10200-*-*
3433 Matsushita MN10300 w/simulator mn10300-*-*
3434 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3435 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3436 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3437 Mitsubishi D10V w/simulator d10v-*-*
3438 Mitsubishi M32R/D w/simulator m32r-*-elf*
3439 Tsqware Sparclet sparclet-*-*
3440 NEC V850 w/simulator v850-*-*
3442 * New debugging protocols
3444 ARM with RDI protocol arm*-*-*
3445 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3446 DDB and LSI variants of PMON protocol mips*-*-*
3447 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3448 PowerPC with SDS protocol powerpc{,le}-*-eabi
3449 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3453 All configurations can now understand and use the DWARF 2 debugging
3454 format. The choice is automatic, if the symbol file contains DWARF 2
3459 GDB now includes basic Java language support. This support is
3460 only useful with Java compilers that produce native machine code.
3462 * solib-absolute-prefix and solib-search-path
3464 For SunOS and SVR4 shared libraries, you may now set the prefix for
3465 loading absolute shared library symbol files, and the search path for
3466 locating non-absolute shared library symbol files.
3468 * Live range splitting
3470 GDB can now effectively debug code for which GCC has performed live
3471 range splitting as part of its optimization. See gdb/doc/LRS for
3472 more details on the expected format of the stabs information.
3476 GDB's support for the GNU Hurd, including thread debugging, has been
3477 updated to work with current versions of the Hurd.
3481 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3482 instruction set. ARM GDB automatically detects when Thumb
3483 instructions are in use, and adjusts disassembly and backtracing
3488 GDB's MIPS target configurations now handle the MIP16 16-bit
3493 GDB now includes support for overlays; if an executable has been
3494 linked such that multiple sections are based at the same address, GDB
3495 will decide which section to use for symbolic info. You can choose to
3496 control the decision manually, using overlay commands, or implement
3497 additional target-side support and use "overlay load-target" to bring
3498 in the overlay mapping. Do "help overlay" for more detail.
3502 The command "info symbol <address>" displays information about
3503 the symbol at the specified address.
3507 The standard remote protocol now includes an extension that allows
3508 asynchronous collection and display of trace data. This requires
3509 extensive support in the target-side debugging stub. Tracing mode
3510 includes a new interaction mode in GDB and new commands: see the
3511 file tracepoint.c for more details.
3515 Configurations for embedded MIPS now include a simulator contributed
3516 by Cygnus Solutions. The simulator supports the instruction sets
3517 of most MIPS variants.
3521 Sparc configurations may now include the ERC32 simulator contributed
3522 by the European Space Agency. The simulator is not built into
3523 Sparc targets by default; configure with --enable-sim to include it.
3527 For target configurations that may include multiple variants of a
3528 basic architecture (such as MIPS and SH), you may now set the
3529 architecture explicitly. "set arch" sets, "info arch" lists
3530 the possible architectures.
3532 *** Changes in GDB-4.16:
3534 * New native configurations
3536 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3537 M68K NetBSD m68k-*-netbsd*
3538 PowerPC AIX 4.x powerpc-*-aix*
3539 PowerPC MacOS powerpc-*-macos*
3540 PowerPC Windows NT powerpcle-*-cygwin32
3541 RS/6000 AIX 4.x rs6000-*-aix4*
3545 ARM with RDP protocol arm-*-*
3546 I960 with MON960 i960-*-coff
3547 MIPS VxWorks mips*-*-vxworks*
3548 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3549 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3551 Matra Sparclet sparclet-*-*
3555 The powerpc-eabi configuration now includes the PSIM simulator,
3556 contributed by Andrew Cagney, with assistance from Mike Meissner.
3557 PSIM is a very elaborate model of the PowerPC, including not only
3558 basic instruction set execution, but also details of execution unit
3559 performance and I/O hardware. See sim/ppc/README for more details.
3563 GDB now works with Solaris 2.5.
3565 * Windows 95/NT native
3567 GDB will now work as a native debugger on Windows 95 and Windows NT.
3568 To build it from source, you must use the "gnu-win32" environment,
3569 which uses a DLL to emulate enough of Unix to run the GNU tools.
3570 Further information, binaries, and sources are available at
3571 ftp.cygnus.com, under pub/gnu-win32.
3573 * dont-repeat command
3575 If a user-defined command includes the command `dont-repeat', then the
3576 command will not be repeated if the user just types return. This is
3577 useful if the command is time-consuming to run, so that accidental
3578 extra keystrokes don't run the same command many times.
3580 * Send break instead of ^C
3582 The standard remote protocol now includes an option to send a break
3583 rather than a ^C to the target in order to interrupt it. By default,
3584 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3586 * Remote protocol timeout
3588 The standard remote protocol includes a new variable `remotetimeout'
3589 that allows you to set the number of seconds before GDB gives up trying
3590 to read from the target. The default value is 2.
3592 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3594 By default GDB will automatically keep track of objects as they are
3595 loaded and unloaded by the dynamic linker. By using the command `set
3596 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3597 when shared library events occur, thus allowing you to set breakpoints
3598 in shared libraries which are explicitly loaded by the inferior.
3600 Note this feature does not work on hpux8. On hpux9 you must link
3601 /usr/lib/end.o into your program. This feature should work
3602 automatically on hpux10.
3604 * Irix 5.x hardware watchpoint support
3606 Irix 5 configurations now support the use of hardware watchpoints.
3608 * Mips protocol "SYN garbage limit"
3610 When debugging a Mips target using the `target mips' protocol, you
3611 may set the number of characters that GDB will ignore by setting
3612 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3613 every character. The default value is 1050.
3615 * Recording and replaying remote debug sessions
3617 If you set `remotelogfile' to the name of a file, gdb will write to it
3618 a recording of a remote debug session. This recording may then be
3619 replayed back to gdb using "gdbreplay". See gdbserver/README for
3620 details. This is useful when you have a problem with GDB while doing
3621 remote debugging; you can make a recording of the session and send it
3622 to someone else, who can then recreate the problem.
3624 * Speedups for remote debugging
3626 GDB includes speedups for downloading and stepping MIPS systems using
3627 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3628 and more efficient S-record downloading.
3630 * Memory use reductions and statistics collection
3632 GDB now uses less memory and reports statistics about memory usage.
3633 Try the `maint print statistics' command, for example.
3635 *** Changes in GDB-4.15:
3637 * Psymtabs for XCOFF
3639 The symbol reader for AIX GDB now uses partial symbol tables. This
3640 can greatly improve startup time, especially for large executables.
3642 * Remote targets use caching
3644 Remote targets now use a data cache to speed up communication with the
3645 remote side. The data cache could lead to incorrect results because
3646 it doesn't know about volatile variables, thus making it impossible to
3647 debug targets which use memory mapped I/O devices. `set remotecache
3648 off' turns the the data cache off.
3650 * Remote targets may have threads
3652 The standard remote protocol now includes support for multiple threads
3653 in the target system, using new protocol commands 'H' and 'T'. See
3654 gdb/remote.c for details.
3658 If GDB is configured with `--enable-netrom', then it will include
3659 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3660 acts as though it is a bank of ROM on the target board, but you can
3661 write into it over the network. GDB's support consists only of
3662 support for fast loading into the emulated ROM; to debug, you must use
3663 another protocol, such as standard remote protocol. The usual
3664 sequence is something like
3666 target nrom <netrom-hostname>
3668 target remote <netrom-hostname>:1235
3672 GDB now includes support for the Apple Macintosh, as a host only. It
3673 may be run as either an MPW tool or as a standalone application, and
3674 it can debug through the serial port. All the usual GDB commands are
3675 available, but to the target command, you must supply "serial" as the
3676 device type instead of "/dev/ttyXX". See mpw-README in the main
3677 directory for more information on how to build. The MPW configuration
3678 scripts */mpw-config.in support only a few targets, and only the
3679 mips-idt-ecoff target has been tested.
3683 GDB configuration now uses autoconf. This is not user-visible,
3684 but does simplify configuration and building.
3688 GDB now supports hpux10.
3690 *** Changes in GDB-4.14:
3692 * New native configurations
3694 x86 FreeBSD i[345]86-*-freebsd
3695 x86 NetBSD i[345]86-*-netbsd
3696 NS32k NetBSD ns32k-*-netbsd
3697 Sparc NetBSD sparc-*-netbsd
3701 A29K VxWorks a29k-*-vxworks
3702 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3703 CPU32 EST-300 emulator m68*-*-est*
3704 PowerPC ELF powerpc-*-elf
3707 * Alpha OSF/1 support for procfs
3709 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3710 possible to attach to running processes. As the mounting of the /proc
3711 filesystem is optional on the Alpha, GDB automatically determines
3712 the availability of /proc during startup. This can lead to problems
3713 if /proc is unmounted after GDB has been started.
3715 * Arguments to user-defined commands
3717 User commands may accept up to 10 arguments separated by whitespace.
3718 Arguments are accessed within the user command via $arg0..$arg9. A
3721 print $arg0 + $arg1 + $arg2
3723 To execute the command use:
3726 Defines the command "adder" which prints the sum of its three arguments.
3727 Note the arguments are text substitutions, so they may reference variables,
3728 use complex expressions, or even perform inferior function calls.
3730 * New `if' and `while' commands
3732 This makes it possible to write more sophisticated user-defined
3733 commands. Both commands take a single argument, which is the
3734 expression to evaluate, and must be followed by the commands to
3735 execute, one per line, if the expression is nonzero, the list being
3736 terminated by the word `end'. The `if' command list may include an
3737 `else' word, which causes the following commands to be executed only
3738 if the expression is zero.
3740 * Fortran source language mode
3742 GDB now includes partial support for Fortran 77. It will recognize
3743 Fortran programs and can evaluate a subset of Fortran expressions, but
3744 variables and functions may not be handled correctly. GDB will work
3745 with G77, but does not yet know much about symbols emitted by other
3748 * Better HPUX support
3750 Most debugging facilities now work on dynamic executables for HPPAs
3751 running hpux9 or later. You can attach to running dynamically linked
3752 processes, but by default the dynamic libraries will be read-only, so
3753 for instance you won't be able to put breakpoints in them. To change
3754 that behavior do the following before running the program:
3760 This will cause the libraries to be mapped private and read-write.
3761 To revert to the normal behavior, do this:
3767 You cannot set breakpoints or examine data in the library until after
3768 the library is loaded if the function/data symbols do not have
3771 GDB can now also read debug symbols produced by the HP C compiler on
3772 HPPAs (sorry, no C++, Fortran or 68k support).
3774 * Target byte order now dynamically selectable
3776 You can choose which byte order to use with a target system, via the
3777 commands "set endian big" and "set endian little", and you can see the
3778 current setting by using "show endian". You can also give the command
3779 "set endian auto", in which case GDB will use the byte order
3780 associated with the executable. Currently, only embedded MIPS
3781 configurations support dynamic selection of target byte order.
3783 * New DOS host serial code
3785 This version uses DPMI interrupts to handle buffered I/O, so you
3786 no longer need to run asynctsr when debugging boards connected to
3789 *** Changes in GDB-4.13:
3791 * New "complete" command
3793 This lists all the possible completions for the rest of the line, if it
3794 were to be given as a command itself. This is intended for use by emacs.
3796 * Trailing space optional in prompt
3798 "set prompt" no longer adds a space for you after the prompt you set. This
3799 allows you to set a prompt which ends in a space or one that does not.
3801 * Breakpoint hit counts
3803 "info break" now displays a count of the number of times the breakpoint
3804 has been hit. This is especially useful in conjunction with "ignore"; you
3805 can ignore a large number of breakpoint hits, look at the breakpoint info
3806 to see how many times the breakpoint was hit, then run again, ignoring one
3807 less than that number, and this will get you quickly to the last hit of
3810 * Ability to stop printing at NULL character
3812 "set print null-stop" will cause GDB to stop printing the characters of
3813 an array when the first NULL is encountered. This is useful when large
3814 arrays actually contain only short strings.
3816 * Shared library breakpoints
3818 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3819 breakpoints in shared libraries before the executable is run.
3821 * Hardware watchpoints
3823 There is a new hardware breakpoint for the watch command for sparclite
3824 targets. See gdb/sparclite/hw_breakpoint.note.
3826 Hardware watchpoints are also now supported under GNU/Linux.
3830 Annotations have been added. These are for use with graphical interfaces,
3831 and are still experimental. Currently only gdba.el uses these.
3833 * Improved Irix 5 support
3835 GDB now works properly with Irix 5.2.
3837 * Improved HPPA support
3839 GDB now works properly with the latest GCC and GAS.
3841 * New native configurations
3843 Sequent PTX4 i[34]86-sequent-ptx4
3844 HPPA running OSF/1 hppa*-*-osf*
3845 Atari TT running SVR4 m68*-*-sysv4*
3846 RS/6000 LynxOS rs6000-*-lynxos*
3850 OS/9000 i[34]86-*-os9k
3851 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
3854 * Hitachi SH7000 and E7000-PC ICE support
3856 There is now support for communicating with the Hitachi E7000-PC ICE.
3857 This is available automatically when GDB is configured for the SH.
3861 As usual, a variety of small fixes and improvements, both generic
3862 and configuration-specific. See the ChangeLog for more detail.
3864 *** Changes in GDB-4.12:
3866 * Irix 5 is now supported
3870 GDB-4.12 on the HPPA has a number of changes which make it unable
3871 to debug the output from the currently released versions of GCC and
3872 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
3873 of GCC and GAS, versions of these tools designed to work with GDB-4.12
3874 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
3877 *** Changes in GDB-4.11:
3879 * User visible changes:
3883 The "set remotedebug" option is now consistent between the mips remote
3884 target, remote targets using the gdb-specific protocol, UDI (AMD's
3885 debug protocol for the 29k) and the 88k bug monitor. It is now an
3886 integer specifying a debug level (normally 0 or 1, but 2 means more
3887 debugging info for the mips target).
3889 * DEC Alpha native support
3891 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
3892 debug info, but GDB works fairly well with the DEC compiler and should
3893 work with a future GCC release. See the README file for a few
3894 Alpha-specific notes.
3896 * Preliminary thread implementation
3898 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
3900 * LynxOS native and target support for 386
3902 This release has been hosted on LynxOS 2.2, and also can be configured
3903 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
3906 * Improvements in C++ mangling/demangling.
3908 This release has much better g++ debugging, specifically in name
3909 mangling/demangling, virtual function calls, print virtual table,
3910 call methods, ...etc.
3912 *** Changes in GDB-4.10:
3914 * User visible changes:
3916 Remote debugging using the GDB-specific (`target remote') protocol now
3917 supports the `load' command. This is only useful if you have some
3918 other way of getting the stub to the target system, and you can put it
3919 somewhere in memory where it won't get clobbered by the download.
3921 Filename completion now works.
3923 When run under emacs mode, the "info line" command now causes the
3924 arrow to point to the line specified. Also, "info line" prints
3925 addresses in symbolic form (as well as hex).
3927 All vxworks based targets now support a user settable option, called
3928 vxworks-timeout. This option represents the number of seconds gdb
3929 should wait for responses to rpc's. You might want to use this if
3930 your vxworks target is, perhaps, a slow software simulator or happens
3931 to be on the far side of a thin network line.
3935 This release contains support for using a DEC alpha as a GDB host for
3936 cross debugging. Native alpha debugging is not supported yet.
3939 *** Changes in GDB-4.9:
3943 This is the first GDB release which is accompanied by a matching testsuite.
3944 The testsuite requires installation of dejagnu, which should be available
3945 via ftp from most sites that carry GNU software.
3949 'Cfront' style demangling has had its name changed to 'ARM' style, to
3950 emphasize that it was written from the specifications in the C++ Annotated
3951 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
3952 disclaimers, it still generated too much confusion with users attempting to
3953 use gdb with AT&T cfront.
3957 GDB now uses a standard remote interface to a simulator library.
3958 So far, the library contains simulators for the Zilog Z8001/2, the
3959 Hitachi H8/300, H8/500 and Super-H.
3961 * New targets supported
3963 H8/300 simulator h8300-hitachi-hms or h8300hms
3964 H8/500 simulator h8500-hitachi-hms or h8500hms
3965 SH simulator sh-hitachi-hms or sh
3966 Z8000 simulator z8k-zilog-none or z8ksim
3967 IDT MIPS board over serial line mips-idt-ecoff
3969 Cross-debugging to GO32 targets is supported. It requires a custom
3970 version of the i386-stub.c module which is integrated with the
3971 GO32 memory extender.
3973 * New remote protocols
3975 MIPS remote debugging protocol.
3977 * New source languages supported
3979 This version includes preliminary support for Chill, a Pascal like language
3980 used by telecommunications companies. Chill support is also being integrated
3981 into the GNU compiler, but we don't know when it will be publically available.
3984 *** Changes in GDB-4.8:
3986 * HP Precision Architecture supported
3988 GDB now supports HP PA-RISC machines running HPUX. A preliminary
3989 version of this support was available as a set of patches from the
3990 University of Utah. GDB does not support debugging of programs
3991 compiled with the HP compiler, because HP will not document their file
3992 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
3993 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
3995 Many problems in the preliminary version have been fixed.
3997 * Faster and better demangling
3999 We have improved template demangling and fixed numerous bugs in the GNU style
4000 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4001 character types (wchar_t) are now supported. Demangling of each symbol is now
4002 only done once, and is cached when the symbol table for a file is read in.
4003 This results in a small increase in memory usage for C programs, a moderate
4004 increase in memory usage for C++ programs, and a fantastic speedup in
4007 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4008 from the specifications in the Annotated Reference Manual, which AT&T's
4009 compiler does not actually implement.
4011 * G++ multiple inheritance compiler problem
4013 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4014 inheritance lattices was reworked to properly discover ambiguities. We
4015 recently found an example which causes this new algorithm to fail in a
4016 very subtle way, producing bad debug information for those classes.
4017 The file 'gcc.patch' (in this directory) can be applied to gcc to
4018 circumvent the problem. A future GCC release will contain a complete
4021 The previous G++ debug info problem (mentioned below for the gdb-4.7
4022 release) is fixed in gcc version 2.3.2.
4024 * Improved configure script
4026 The `configure' script will now attempt to guess your system type if
4027 you don't supply a host system type. The old scheme of supplying a
4028 host system triplet is preferable over using this. All the magic is
4029 done in the new `config.guess' script. Examine it for details.
4031 We have also brought our configure script much more in line with the FSF's
4032 version. It now supports the --with-xxx options. In particular,
4033 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4034 The resulting GDB will not be able to read arbitrary object file formats --
4035 only the format ``expected'' to be used on the configured target system.
4036 We hope to make this the default in a future release.
4038 * Documentation improvements
4040 There's new internal documentation on how to modify GDB, and how to
4041 produce clean changes to the code. We implore people to read it
4042 before submitting changes.
4044 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4045 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4046 `info' files are also provided. To build `info' files from scratch,
4047 you will need the latest `makeinfo' release, which will be available in
4048 a future texinfo-X.Y release.
4050 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4051 We're not sure exactly which versions have this problem, but it has
4052 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4053 or better. If that isn't possible, there is a patch in
4054 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4055 around this problem.
4059 GDB now supports array constants that can be used in expressions typed in by
4060 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4061 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4064 The new directory `gdb/sparclite' contains a program that demonstrates
4065 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4067 * New native hosts supported
4069 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4070 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4072 * New targets supported
4074 AMD 29k family via UDI a29k-amd-udi or udi29k
4076 * New file formats supported
4078 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4079 HPUX core files, and SCO 3.2v2 core files.
4083 Attaching to processes now works again; thanks for the many bug reports.
4085 We have also stomped on a bunch of core dumps caused by
4086 printf_filtered("%s") problems.
4088 We eliminated a copyright problem on the rpc and ptrace header files
4089 for VxWorks, which was discovered at the last minute during the 4.7
4090 release. You should now be able to build a VxWorks GDB.
4092 You can now interrupt gdb while an attached process is running. This
4093 will cause the attached process to stop, and give control back to GDB.
4095 We fixed problems caused by using too many file descriptors
4096 for reading symbols from object files and libraries. This was
4097 especially a problem for programs that used many (~100) shared
4100 The `step' command now only enters a subroutine if there is line number
4101 information for the subroutine. Otherwise it acts like the `next'
4102 command. Previously, `step' would enter subroutines if there was
4103 any debugging information about the routine. This avoids problems
4104 when using `cc -g1' on MIPS machines.
4106 * Internal improvements
4108 GDB's internal interfaces have been improved to make it easier to support
4109 debugging of multiple languages in the future.
4111 GDB now uses a common structure for symbol information internally.
4112 Minimal symbols (derived from linkage symbols in object files), partial
4113 symbols (from a quick scan of debug information), and full symbols
4114 contain a common subset of information, making it easier to write
4115 shared code that handles any of them.
4117 * New command line options
4119 We now accept --silent as an alias for --quiet.
4123 The memory-mapped-malloc library is now licensed under the GNU Library
4124 General Public License.
4126 *** Changes in GDB-4.7:
4128 * Host/native/target split
4130 GDB has had some major internal surgery to untangle the support for
4131 hosts and remote targets. Now, when you configure GDB for a remote
4132 target, it will no longer load in all of the support for debugging
4133 local programs on the host. When fully completed and tested, this will
4134 ensure that arbitrary host/target combinations are possible.
4136 The primary conceptual shift is to separate the non-portable code in
4137 GDB into three categories. Host specific code is required any time GDB
4138 is compiled on that host, regardless of the target. Target specific
4139 code relates to the peculiarities of the target, but can be compiled on
4140 any host. Native specific code is everything else: it can only be
4141 built when the host and target are the same system. Child process
4142 handling and core file support are two common `native' examples.
4144 GDB's use of /proc for controlling Unix child processes is now cleaner.
4145 It has been split out into a single module under the `target_ops' vector,
4146 plus two native-dependent functions for each system that uses /proc.
4148 * New hosts supported
4150 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4151 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4152 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4154 * New targets supported
4156 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4157 68030 and CPU32 m68030-*-*, m68332-*-*
4159 * New native hosts supported
4161 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4162 (386bsd is not well tested yet)
4163 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4165 * New file formats supported
4167 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4168 supports reading of `a.out.adobe' object files, which are an a.out
4169 format extended with minimal information about multiple sections.
4173 `show copying' is the same as the old `info copying'.
4174 `show warranty' is the same as `info warrantee'.
4175 These were renamed for consistency. The old commands continue to work.
4177 `info handle' is a new alias for `info signals'.
4179 You can now define pre-command hooks, which attach arbitrary command
4180 scripts to any command. The commands in the hook will be executed
4181 prior to the user's command. You can also create a hook which will be
4182 executed whenever the program stops. See gdb.texinfo.
4186 We now deal with Cfront style name mangling, and can even extract type
4187 info from mangled symbols. GDB can automatically figure out which
4188 symbol mangling style your C++ compiler uses.
4190 Calling of methods and virtual functions has been improved as well.
4194 The crash that occured when debugging Sun Ansi-C compiled binaries is
4195 fixed. This was due to mishandling of the extra N_SO stabs output
4198 We also finally got Ultrix 4.2 running in house, and fixed core file
4199 support, with help from a dozen people on the net.
4201 John M. Farrell discovered that the reason that single-stepping was so
4202 slow on all of the Mips based platforms (primarily SGI and DEC) was
4203 that we were trying to demangle and lookup a symbol used for internal
4204 purposes on every instruction that was being stepped through. Changing
4205 the name of that symbol so that it couldn't be mistaken for a C++
4206 mangled symbol sped things up a great deal.
4208 Rich Pixley sped up symbol lookups in general by getting much smarter
4209 about when C++ symbol mangling is necessary. This should make symbol
4210 completion (TAB on the command line) much faster. It's not as fast as
4211 we'd like, but it's significantly faster than gdb-4.6.
4215 A new user controllable variable 'call_scratch_address' can
4216 specify the location of a scratch area to be used when GDB
4217 calls a function in the target. This is necessary because the
4218 usual method of putting the scratch area on the stack does not work
4219 in systems that have separate instruction and data spaces.
4221 We integrated changes to support the 29k UDI (Universal Debugger
4222 Interface), but discovered at the last minute that we didn't have all
4223 of the appropriate copyright paperwork. We are working with AMD to
4224 resolve this, and hope to have it available soon.
4228 We have sped up the remote serial line protocol, especially for targets
4229 with lots of registers. It now supports a new `expedited status' ('T')
4230 message which can be used in place of the existing 'S' status message.
4231 This allows the remote stub to send only the registers that GDB
4232 needs to make a quick decision about single-stepping or conditional
4233 breakpoints, eliminating the need to fetch the entire register set for
4234 each instruction being stepped through.
4236 The GDB remote serial protocol now implements a write-through cache for
4237 registers, only re-reading the registers if the target has run.
4239 There is also a new remote serial stub for SPARC processors. You can
4240 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4241 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4242 processor with a serial port.
4246 Configure.in files have become much easier to read and modify. A new
4247 `table driven' format makes it more obvious what configurations are
4248 supported, and what files each one uses.
4252 There is a new opcodes library which will eventually contain all of the
4253 disassembly routines and opcode tables. At present, it only contains
4254 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4255 disassembler (binutils/objdump) to share these routines.
4257 The libiberty library is now copylefted under the GNU Library General
4258 Public License. This allows more liberal use, and was done so libg++
4259 can use it. This makes no difference to GDB, since the Library License
4260 grants all the rights from the General Public License.
4264 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4265 reference to the stabs symbol info used by the debugger. It is (as far
4266 as we know) the only published document on this fascinating topic. We
4267 encourage you to read it, compare it to the stabs information on your
4268 system, and send improvements on the document in general (to
4269 bug-gdb@prep.ai.mit.edu).
4271 And, of course, many bugs have been fixed.
4274 *** Changes in GDB-4.6:
4276 * Better support for C++ function names
4278 GDB now accepts as input the "demangled form" of C++ overloaded function
4279 names and member function names, and can do command completion on such names
4280 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4281 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4282 Make use of command completion, it is your friend.
4284 GDB also now accepts a variety of C++ mangled symbol formats. They are
4285 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4286 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4287 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4288 for the list of formats.
4290 * G++ symbol mangling problem
4292 Recent versions of gcc have a bug in how they emit debugging information for
4293 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4294 directory) can be applied to gcc to fix the problem. Alternatively, if you
4295 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4296 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4297 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4300 * New 'maintenance' command
4302 All of the commands related to hacking GDB internals have been moved out of
4303 the main command set, and now live behind the 'maintenance' command. This
4304 can also be abbreviated as 'mt'. The following changes were made:
4306 dump-me -> maintenance dump-me
4307 info all-breakpoints -> maintenance info breakpoints
4308 printmsyms -> maintenance print msyms
4309 printobjfiles -> maintenance print objfiles
4310 printpsyms -> maintenance print psymbols
4311 printsyms -> maintenance print symbols
4313 The following commands are new:
4315 maintenance demangle Call internal GDB demangler routine to
4316 demangle a C++ link name and prints the result.
4317 maintenance print type Print a type chain for a given symbol
4319 * Change to .gdbinit file processing
4321 We now read the $HOME/.gdbinit file before processing the argv arguments
4322 (e.g. reading symbol files or core files). This allows global parameters to
4323 be set, which will apply during the symbol reading. The ./.gdbinit is still
4324 read after argv processing.
4326 * New hosts supported
4328 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4330 GNU/Linux support i386-unknown-linux or linux
4332 We are also including code to support the HP/PA running BSD and HPUX. This
4333 is almost guaranteed not to work, as we didn't have time to test or build it
4334 for this release. We are including it so that the more adventurous (or
4335 masochistic) of you can play with it. We also had major problems with the
4336 fact that the compiler that we got from HP doesn't support the -g option.
4339 * New targets supported
4341 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4343 * More smarts about finding #include files
4345 GDB now remembers the compilation directory for all include files, and for
4346 all files from which C is generated (like yacc and lex sources). This
4347 greatly improves GDB's ability to find yacc/lex sources, and include files,
4348 especially if you are debugging your program from a directory different from
4349 the one that contains your sources.
4351 We also fixed a bug which caused difficulty with listing and setting
4352 breakpoints in include files which contain C code. (In the past, you had to
4353 try twice in order to list an include file that you hadn't looked at before.)
4355 * Interesting infernals change
4357 GDB now deals with arbitrary numbers of sections, where the symbols for each
4358 section must be relocated relative to that section's landing place in the
4359 target's address space. This work was needed to support ELF with embedded
4360 stabs used by Solaris-2.0.
4362 * Bug fixes (of course!)
4364 There have been loads of fixes for the following things:
4365 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4366 i960, stabs, DOS(GO32), procfs, etc...
4368 See the ChangeLog for details.
4370 *** Changes in GDB-4.5:
4372 * New machines supported (host and target)
4374 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4376 SGI Irix-4.x mips-sgi-irix4 or iris4
4378 * New malloc package
4380 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4381 Mmalloc is capable of handling mutiple heaps of memory. It is also
4382 capable of saving a heap to a file, and then mapping it back in later.
4383 This can be used to greatly speedup the startup of GDB by using a
4384 pre-parsed symbol table which lives in a mmalloc managed heap. For
4385 more details, please read mmalloc/mmalloc.texi.
4389 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4390 'help info proc' for details.
4392 * MIPS ecoff symbol table format
4394 The code that reads MIPS symbol table format is now supported on all hosts.
4395 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4398 * File name changes for MS-DOS
4400 Many files in the config directories have been renamed to make it easier to
4401 support GDB on MS-DOSe systems (which have very restrictive file name
4402 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4403 environment) is close to working but has some remaining problems. Note
4404 that debugging of DOS programs is not supported, due to limitations
4405 in the ``operating system'', but it can be used to host cross-debugging.
4407 * Cross byte order fixes
4409 Many fixes have been made to support cross debugging of Sparc and MIPS
4410 targets from hosts whose byte order differs.
4412 * New -mapped and -readnow options
4414 If memory-mapped files are available on your system through the 'mmap'
4415 system call, you can use the -mapped option on the `file' or
4416 `symbol-file' commands to cause GDB to write the symbols from your
4417 program into a reusable file. If the program you are debugging is
4418 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4419 Future GDB debugging sessions will notice the presence of this file,
4420 and will quickly map in symbol information from it, rather than reading
4421 the symbol table from the executable program. Using the '-mapped'
4422 option in a GDB `file' or `symbol-file' command has the same effect as
4423 starting GDB with the '-mapped' command-line option.
4425 You can cause GDB to read the entire symbol table immediately by using
4426 the '-readnow' option with any of the commands that load symbol table
4427 information (or on the GDB command line). This makes the command
4428 slower, but makes future operations faster.
4430 The -mapped and -readnow options are typically combined in order to
4431 build a `fred.syms' file that contains complete symbol information.
4432 A simple GDB invocation to do nothing but build a `.syms' file for future
4435 gdb -batch -nx -mapped -readnow programname
4437 The `.syms' file is specific to the host machine on which GDB is run.
4438 It holds an exact image of GDB's internal symbol table. It cannot be
4439 shared across multiple host platforms.
4441 * longjmp() handling
4443 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4444 siglongjmp() without losing control. This feature has not yet been ported to
4445 all systems. It currently works on many 386 platforms, all MIPS-based
4446 platforms (SGI, DECstation, etc), and Sun3/4.
4450 Preliminary work has been put in to support the new Solaris OS from Sun. At
4451 this time, it can control and debug processes, but it is not capable of
4456 As always, many many bug fixes. The major areas were with g++, and mipsread.
4457 People using the MIPS-based platforms should experience fewer mysterious
4458 crashes and trashed symbol tables.
4460 *** Changes in GDB-4.4:
4462 * New machines supported (host and target)
4464 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4466 BSD Reno on Vax vax-dec-bsd
4467 Ultrix on Vax vax-dec-ultrix
4469 * New machines supported (target)
4471 AMD 29000 embedded, using EBMON a29k-none-none
4475 GDB continues to improve its handling of C++. `References' work better.
4476 The demangler has also been improved, and now deals with symbols mangled as
4477 per the Annotated C++ Reference Guide.
4479 GDB also now handles `stabs' symbol information embedded in MIPS
4480 `ecoff' symbol tables. Since the ecoff format was not easily
4481 extensible to handle new languages such as C++, this appeared to be a
4482 good way to put C++ debugging info into MIPS binaries. This option
4483 will be supported in the GNU C compiler, version 2, when it is
4486 * New features for SVR4
4488 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4489 shared libraries. Debugging dynamically linked programs should present
4490 only minor differences from debugging statically linked programs.
4492 The `info proc' command will print out information about any process
4493 on an SVR4 system (including the one you are debugging). At the moment,
4494 it prints the address mappings of the process.
4496 If you bring up GDB on another SVR4 system, please send mail to
4497 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4499 * Better dynamic linking support in SunOS
4501 Reading symbols from shared libraries which contain debugging symbols
4502 now works properly. However, there remain issues such as automatic
4503 skipping of `transfer vector' code during function calls, which
4504 make it harder to debug code in a shared library, than to debug the
4505 same code linked statically.
4509 GDB is now using the latest `getopt' routines from the FSF. This
4510 version accepts the -- prefix for options with long names. GDB will
4511 continue to accept the old forms (-option and +option) as well.
4512 Various single letter abbreviations for options have been explicity
4513 added to the option table so that they won't get overshadowed in the
4514 future by other options that begin with the same letter.
4518 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4519 Many assorted bugs have been handled. Many more remain to be handled.
4520 See the various ChangeLog files (primarily in gdb and bfd) for details.
4523 *** Changes in GDB-4.3:
4525 * New machines supported (host and target)
4527 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4528 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4529 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4531 * Almost SCO Unix support
4533 We had hoped to support:
4534 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4535 (except for core file support), but we discovered very late in the release
4536 that it has problems with process groups that render gdb unusable. Sorry
4537 about that. I encourage people to fix it and post the fixes.
4539 * Preliminary ELF and DWARF support
4541 GDB can read ELF object files on System V Release 4, and can handle
4542 debugging records for C, in DWARF format, in ELF files. This support
4543 is preliminary. If you bring up GDB on another SVR4 system, please
4544 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4549 GDB now uses the latest `readline' library. One user-visible change
4550 is that two tabs will list possible command completions, which previously
4551 required typing M-? (meta-question mark, or ESC ?).
4555 The `stepi' bug that many of you noticed has been squashed.
4556 Many bugs in C++ have been handled. Many more remain to be handled.
4557 See the various ChangeLog files (primarily in gdb and bfd) for details.
4559 * State of the MIPS world (in case you wondered):
4561 GDB can understand the symbol tables emitted by the compilers
4562 supplied by most vendors of MIPS-based machines, including DEC. These
4563 symbol tables are in a format that essentially nobody else uses.
4565 Some versions of gcc come with an assembler post-processor called
4566 mips-tfile. This program is required if you want to do source-level
4567 debugging of gcc-compiled programs. I believe FSF does not ship
4568 mips-tfile with gcc version 1, but it will eventually come with gcc
4571 Debugging of g++ output remains a problem. g++ version 1.xx does not
4572 really support it at all. (If you're lucky, you should be able to get
4573 line numbers and stack traces to work, but no parameters or local
4574 variables.) With some work it should be possible to improve the
4577 When gcc version 2 is released, you will have somewhat better luck.
4578 However, even then you will get confusing results for inheritance and
4581 We will eventually provide full debugging of g++ output on
4582 DECstations. This will probably involve some kind of stabs-in-ecoff
4583 encapulation, but the details have not been worked out yet.
4586 *** Changes in GDB-4.2:
4588 * Improved configuration
4590 Only one copy of `configure' exists now, and it is not self-modifying.
4591 Porting BFD is simpler.
4595 The `step' and `next' commands now only stop at the first instruction
4596 of a source line. This prevents the multiple stops that used to occur
4597 in switch statements, for-loops, etc. `Step' continues to stop if a
4598 function that has debugging information is called within the line.
4602 Lots of small bugs fixed. More remain.
4604 * New host supported (not target)
4606 Intel 386 PC clone running Mach i386-none-mach
4609 *** Changes in GDB-4.1:
4611 * Multiple source language support
4613 GDB now has internal scaffolding to handle several source languages.
4614 It determines the type of each source file from its filename extension,
4615 and will switch expression parsing and number formatting to match the
4616 language of the function in the currently selected stack frame.
4617 You can also specifically set the language to be used, with
4618 `set language c' or `set language modula-2'.
4622 GDB now has preliminary support for the GNU Modula-2 compiler,
4623 currently under development at the State University of New York at
4624 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4625 continue through the fall of 1991 and into 1992.
4627 Other Modula-2 compilers are currently not supported, and attempting to
4628 debug programs compiled with them will likely result in an error as the
4629 symbol table is read. Feel free to work on it, though!
4631 There are hooks in GDB for strict type checking and range checking,
4632 in the `Modula-2 philosophy', but they do not currently work.
4636 GDB can now write to executable and core files (e.g. patch
4637 a variable's value). You must turn this switch on, specify
4638 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4639 by assigning a new value to a variable. Modifications take
4642 * Automatic SunOS shared library reading
4644 When you run your program, GDB automatically determines where its
4645 shared libraries (if any) have been loaded, and reads their symbols.
4646 The `share' command is no longer needed. This also works when
4647 examining core files.
4651 You can specify the number of lines that the `list' command shows.
4654 * New machines supported (host and target)
4656 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4657 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4658 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4660 * New hosts supported (not targets)
4662 IBM RT/PC: romp-ibm-aix or rtpc
4664 * New targets supported (not hosts)
4666 AMD 29000 embedded with COFF a29k-none-coff
4667 AMD 29000 embedded with a.out a29k-none-aout
4668 Ultracomputer remote kernel debug a29k-nyu-kern
4670 * New remote interfaces
4676 *** Changes in GDB-4.0:
4680 Wide output is wrapped at good places to make the output more readable.
4682 Gdb now supports cross-debugging from a host machine of one type to a
4683 target machine of another type. Communication with the target system
4684 is over serial lines. The ``target'' command handles connecting to the
4685 remote system; the ``load'' command will download a program into the
4686 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4687 also supports debugging of realtime processes running under VxWorks,
4688 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4689 stub on the target system.
4691 New CPUs supported include the AMD 29000 and Intel 960.
4693 GDB now reads object files and symbol tables via a ``binary file''
4694 library, which allows a single copy of GDB to debug programs of multiple
4695 object file types such as a.out and coff.
4697 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4698 refcard.dvi and refcard.ps are available to format it).
4701 * Control-Variable user interface simplified
4703 All variables that control the operation of the debugger can be set
4704 by the ``set'' command, and displayed by the ``show'' command.
4706 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4707 ``Show prompt'' produces the response:
4708 Gdb's prompt is new-gdb=>.
4710 What follows are the NEW set commands. The command ``help set'' will
4711 print a complete list of old and new set commands. ``help set FOO''
4712 will give a longer description of the variable FOO. ``show'' will show
4713 all of the variable descriptions and their current settings.
4715 confirm on/off: Enables warning questions for operations that are
4716 hard to recover from, e.g. rerunning the program while
4717 it is already running. Default is ON.
4719 editing on/off: Enables EMACS style command line editing
4720 of input. Previous lines can be recalled with
4721 control-P, the current line can be edited with control-B,
4722 you can search for commands with control-R, etc.
4725 history filename NAME: NAME is where the gdb command history
4726 will be stored. The default is .gdb_history,
4727 or the value of the environment variable
4730 history size N: The size, in commands, of the command history. The
4731 default is 256, or the value of the environment variable
4734 history save on/off: If this value is set to ON, the history file will
4735 be saved after exiting gdb. If set to OFF, the
4736 file will not be saved. The default is OFF.
4738 history expansion on/off: If this value is set to ON, then csh-like
4739 history expansion will be performed on
4740 command line input. The default is OFF.
4742 radix N: Sets the default radix for input and output. It can be set
4743 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4744 in the current radix, so "set radix 10" is always a no-op.
4746 height N: This integer value is the number of lines on a page. Default
4747 is 24, the current `stty rows'' setting, or the ``li#''
4748 setting from the termcap entry matching the environment
4751 width N: This integer value is the number of characters on a line.
4752 Default is 80, the current `stty cols'' setting, or the ``co#''
4753 setting from the termcap entry matching the environment
4756 Note: ``set screensize'' is obsolete. Use ``set height'' and
4757 ``set width'' instead.
4759 print address on/off: Print memory addresses in various command displays,
4760 such as stack traces and structure values. Gdb looks
4761 more ``symbolic'' if you turn this off; it looks more
4762 ``machine level'' with it on. Default is ON.
4764 print array on/off: Prettyprint arrays. New convenient format! Default
4767 print demangle on/off: Print C++ symbols in "source" form if on,
4770 print asm-demangle on/off: Same, for assembler level printouts
4773 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4776 * Support for Epoch Environment.
4778 The epoch environment is a version of Emacs v18 with windowing. One
4779 new command, ``inspect'', is identical to ``print'', except that if you
4780 are running in the epoch environment, the value is printed in its own
4784 * Support for Shared Libraries
4786 GDB can now debug programs and core files that use SunOS shared libraries.
4787 Symbols from a shared library cannot be referenced
4788 before the shared library has been linked with the program (this
4789 happens after you type ``run'' and before the function main() is entered).
4790 At any time after this linking (including when examining core files
4791 from dynamically linked programs), gdb reads the symbols from each
4792 shared library when you type the ``sharedlibrary'' command.
4793 It can be abbreviated ``share''.
4795 sharedlibrary REGEXP: Load shared object library symbols for files
4796 matching a unix regular expression. No argument
4797 indicates to load symbols for all shared libraries.
4799 info sharedlibrary: Status of loaded shared libraries.
4804 A watchpoint stops execution of a program whenever the value of an
4805 expression changes. Checking for this slows down execution
4806 tremendously whenever you are in the scope of the expression, but is
4807 quite useful for catching tough ``bit-spreader'' or pointer misuse
4808 problems. Some machines such as the 386 have hardware for doing this
4809 more quickly, and future versions of gdb will use this hardware.
4811 watch EXP: Set a watchpoint (breakpoint) for an expression.
4813 info watchpoints: Information about your watchpoints.
4815 delete N: Deletes watchpoint number N (same as breakpoints).
4816 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4817 enable N: Re-enables watchpoint number N (same as breakpoints).
4820 * C++ multiple inheritance
4822 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4825 * C++ exception handling
4827 Gdb now supports limited C++ exception handling. Besides the existing
4828 ability to breakpoint on an exception handler, gdb can breakpoint on
4829 the raising of an exception (before the stack is peeled back to the
4832 catch FOO: If there is a FOO exception handler in the dynamic scope,
4833 set a breakpoint to catch exceptions which may be raised there.
4834 Multiple exceptions (``catch foo bar baz'') may be caught.
4836 info catch: Lists all exceptions which may be caught in the
4837 current stack frame.
4840 * Minor command changes
4842 The command ``call func (arg, arg, ...)'' now acts like the print
4843 command, except it does not print or save a value if the function's result
4844 is void. This is similar to dbx usage.
4846 The ``up'' and ``down'' commands now always print the frame they end up
4847 at; ``up-silently'' and `down-silently'' can be used in scripts to change
4848 frames without printing.
4850 * New directory command
4852 'dir' now adds directories to the FRONT of the source search path.
4853 The path starts off empty. Source files that contain debug information
4854 about the directory in which they were compiled can be found even
4855 with an empty path; Sun CC and GCC include this information. If GDB can't
4856 find your source file in the current directory, type "dir .".
4858 * Configuring GDB for compilation
4860 For normal use, type ``./configure host''. See README or gdb.texinfo
4863 GDB now handles cross debugging. If you are remotely debugging between
4864 two different machines, type ``./configure host -target=targ''.
4865 Host is the machine where GDB will run; targ is the machine
4866 where the program that you are debugging will run.