1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB now has experimental support for the compilation and injection of
7 C++ source code into the inferior. This beta release does not include
8 support for several language features, such as templates, constructors,
11 This feature requires GCC 7.1 or higher built with libcp1.so
14 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
15 can be passed using the '[ADDRESS]:PORT' notation, or the regular
16 'ADDRESS:PORT' method.
18 * DWARF index cache: GDB can now automatically save indices of DWARF
19 symbols on disk to speed up further loading of the same binaries.
21 * GDB in batch mode now exits with status 1 if the last command to be
26 set debug compile-cplus-types
27 show debug compile-cplus-types
28 Control the display of debug output about type conversion in the
29 C++ compile feature. Commands have no effect while compiliong
34 Control whether debug output about files/functions skipping is
37 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
38 Apply a command to some frames.
39 FLAG arguments allow to control what output to produce and how to handle
40 errors raised when applying COMMAND to a frame.
43 Apply a command to all threads (ignoring errors and empty output).
44 Shortcut for 'thread apply all -s COMMAND'.
47 Apply a command to all frames (ignoring errors and empty output).
48 Shortcut for 'frame apply all -s COMMAND'.
51 Apply a command to all frames of all threads (ignoring errors and empty
53 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
55 maint set dwarf unwinders (on|off)
56 maint show dwarf unwinders
57 Control whether DWARF unwinders can be used.
61 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
62 The 'thread apply' command accepts new FLAG arguments.
63 FLAG arguments allow to control what output to produce and how to handle
64 errors raised when applying COMMAND to a thread.
68 ** The '-data-disassemble' MI command now accepts an '-a' option to
69 disassemble the whole function surrounding the given program
70 counter value or function name. Support for this feature can be
71 verified by using the "-list-features" command, which should
72 contain "data-disassemble-a-option".
74 ** Command responses and notifications that include a frame now include
75 the frame's architecture in a new "arch" attribute.
77 * New native configurations
79 GNU/Linux/RISC-V riscv*-*-linux*
83 GNU/Linux/RISC-V riscv*-*-linux*
85 CSKY GNU/LINUX csky*-*-linux
89 ** The gdb.Inferior type has a new 'progspace' property, which is the program
90 space associated to that inferior.
92 *** Changes in GDB 8.2
94 * The 'set disassembler-options' command now supports specifying options
97 * The 'symbol-file' command now accepts an '-o' option to add a relative
98 offset to all sections.
100 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
101 a relative offset to all sections, but it allows to override the load
102 address of individual sections using '-s'.
104 * The 'add-symbol-file' command no longer requires the second argument
105 (address of the text section).
107 * The endianness used with the 'set endian auto' mode in the absence of
108 an executable selected for debugging is now the last endianness chosen
109 either by one of the 'set endian big' and 'set endian little' commands
110 or by inferring from the last executable used, rather than the startup
113 * The pager now allows a "c" response, meaning to disable the pager
114 for the rest of the current command.
116 * The commands 'info variables/functions/types' now show the source line
117 numbers of symbol definitions when available.
119 * 'info proc' now works on running processes on FreeBSD systems and core
120 files created on FreeBSD systems.
122 * C expressions can now use _Alignof, and C++ expressions can now use
125 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
126 the vector length while the process is running.
132 Control display of debugging info regarding the FreeBSD native target.
134 set|show varsize-limit
135 This new setting allows the user to control the maximum size of Ada
136 objects being printed when those objects have a variable type,
137 instead of that maximum size being hardcoded to 65536 bytes.
139 set|show record btrace cpu
140 Controls the processor to be used for enabling errata workarounds for
143 maint check libthread-db
144 Run integrity checks on the current inferior's thread debugging
147 maint set check-libthread-db (on|off)
148 maint show check-libthread-db
149 Control whether to run integrity checks on inferior specific thread
150 debugging libraries as they are loaded. The default is not to
155 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
157 ** The commands attached to a breakpoint can be set by assigning to
158 the breakpoint's "commands" field.
160 ** gdb.execute can now execute multi-line gdb commands.
162 ** The new functions gdb.convenience_variable and
163 gdb.set_convenience_variable can be used to get and set the value
164 of convenience variables.
166 ** A gdb.Parameter will no longer print the "set" help text on an
167 ordinary "set"; instead by default a "set" will be silent unless
168 the get_set_string method returns a non-empty string.
172 RiscV ELF riscv*-*-elf
174 * Removed targets and native configurations
176 m88k running OpenBSD m88*-*-openbsd*
177 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
178 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
179 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
181 * Aarch64/Linux hardware watchpoints improvements
183 Hardware watchpoints on unaligned addresses are now properly
184 supported when running Linux kernel 4.10 or higher: read and access
185 watchpoints are no longer spuriously missed, and all watchpoints
186 lengths between 1 and 8 bytes are supported. On older kernels,
187 watchpoints set on unaligned addresses are no longer missed, with
188 the tradeoff that there is a possibility of false hits being
193 --enable-codesign=CERT
194 This can be used to invoke "codesign -s CERT" after building gdb.
195 This option is useful on macOS, where code signing is required for
196 gdb to work properly.
198 --disable-gdbcli has been removed
199 This is now silently accepted, but does nothing.
201 *** Changes in GDB 8.1
203 * GDB now supports dynamically creating arbitrary register groups specified
204 in XML target descriptions. This allows for finer grain grouping of
205 registers on systems with a large amount of registers.
207 * The 'ptype' command now accepts a '/o' flag, which prints the
208 offsets and sizes of fields in a struct, like the pahole(1) tool.
210 * New "--readnever" command line option instructs GDB to not read each
211 symbol file's symbolic debug information. This makes startup faster
212 but at the expense of not being able to perform symbolic debugging.
213 This option is intended for use cases where symbolic debugging will
214 not be used, e.g., when you only need to dump the debuggee's core.
216 * GDB now uses the GNU MPFR library, if available, to emulate target
217 floating-point arithmetic during expression evaluation when the target
218 uses different floating-point formats than the host. At least version
219 3.1 of GNU MPFR is required.
221 * GDB now supports access to the guarded-storage-control registers and the
222 software-based guarded-storage broadcast control registers on IBM z14.
224 * On Unix systems, GDB now supports transmitting environment variables
225 that are to be set or unset to GDBserver. These variables will
226 affect the environment to be passed to the remote inferior.
228 To inform GDB of environment variables that are to be transmitted to
229 GDBserver, use the "set environment" command. Only user set
230 environment variables are sent to GDBserver.
232 To inform GDB of environment variables that are to be unset before
233 the remote inferior is started by the GDBserver, use the "unset
234 environment" command.
236 * Completion improvements
238 ** GDB can now complete function parameters in linespecs and
239 explicit locations without quoting. When setting breakpoints,
240 quoting around functions names to help with TAB-completion is
241 generally no longer necessary. For example, this now completes
244 (gdb) b function(in[TAB]
245 (gdb) b function(int)
247 Related, GDB is no longer confused with completing functions in
248 C++ anonymous namespaces:
251 (gdb) b (anonymous namespace)::[TAB][TAB]
252 (anonymous namespace)::a_function()
253 (anonymous namespace)::b_function()
255 ** GDB now has much improved linespec and explicit locations TAB
256 completion support, that better understands what you're
257 completing and offers better suggestions. For example, GDB no
258 longer offers data symbols as possible completions when you're
259 setting a breakpoint.
261 ** GDB now TAB-completes label symbol names.
263 ** The "complete" command now mimics TAB completion accurately.
265 * New command line options (gcore)
268 Dump all memory mappings.
270 * Breakpoints on C++ functions are now set on all scopes by default
272 By default, breakpoints on functions/methods are now interpreted as
273 specifying all functions with the given name ignoring missing
274 leading scopes (namespaces and classes).
276 For example, assuming a C++ program with symbols named:
281 both commands "break func()" and "break B::func()" set a breakpoint
284 You can use the new flag "-qualified" to override this. This makes
285 GDB interpret the specified function name as a complete
286 fully-qualified name instead. For example, using the same C++
287 program, the "break -q B::func" command sets a breakpoint on
288 "B::func", only. A parameter has been added to the Python
289 gdb.Breakpoint constructor to achieve the same result when creating
290 a breakpoint from Python.
292 * Breakpoints on functions marked with C++ ABI tags
294 GDB can now set breakpoints on functions marked with C++ ABI tags
295 (e.g., [abi:cxx11]). See here for a description of ABI tags:
296 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
298 Functions with a C++11 abi tag are demangled/displayed like this:
300 function[abi:cxx11](int)
303 You can now set a breakpoint on such functions simply as if they had
306 (gdb) b function(int)
308 Or if you need to disambiguate between tags, like:
310 (gdb) b function[abi:other_tag](int)
312 Tab completion was adjusted accordingly as well.
316 ** New events gdb.new_inferior, gdb.inferior_deleted, and
317 gdb.new_thread are emitted. See the manual for further
318 description of these.
320 ** A new function, "gdb.rbreak" has been added to the Python API.
321 This function allows the setting of a large number of breakpoints
322 via a regex pattern in Python. See the manual for further details.
324 ** Python breakpoints can now accept explicit locations. See the
325 manual for a further description of this feature.
328 * New features in the GDB remote stub, GDBserver
330 ** GDBserver is now able to start inferior processes with a
331 specified initial working directory.
333 The user can set the desired working directory to be used from
334 GDB using the new "set cwd" command.
336 ** New "--selftest" command line option runs some GDBserver self
337 tests. These self tests are disabled in releases.
339 ** On Unix systems, GDBserver now does globbing expansion and variable
340 substitution in inferior command line arguments.
342 This is done by starting inferiors using a shell, like GDB does.
343 See "set startup-with-shell" in the user manual for how to disable
344 this from GDB when using "target extended-remote". When using
345 "target remote", you can disable the startup with shell by using the
346 new "--no-startup-with-shell" GDBserver command line option.
348 ** On Unix systems, GDBserver now supports receiving environment
349 variables that are to be set or unset from GDB. These variables
350 will affect the environment to be passed to the inferior.
352 * When catching an Ada exception raised with a message, GDB now prints
353 the message in the catchpoint hit notification. In GDB/MI mode, that
354 information is provided as an extra field named "exception-message"
355 in the *stopped notification.
357 * Trait objects can now be inspected When debugging Rust code. This
358 requires compiler support which will appear in Rust 1.24.
362 QEnvironmentHexEncoded
363 Inform GDBserver of an environment variable that is to be passed to
364 the inferior when starting it.
367 Inform GDBserver of an environment variable that is to be unset
368 before starting the remote inferior.
371 Inform GDBserver that the environment should be reset (i.e.,
372 user-set environment variables should be unset).
375 Indicates whether the inferior must be started with a shell or not.
378 Tell GDBserver that the inferior to be started should use a specific
381 * The "maintenance print c-tdesc" command now takes an optional
382 argument which is the file name of XML target description.
384 * The "maintenance selftest" command now takes an optional argument to
385 filter the tests to be run.
387 * The "enable", and "disable" commands now accept a range of
388 breakpoint locations, e.g. "enable 1.3-5".
393 Set and show the current working directory for the inferior.
396 Set and show compilation command used for compiling and injecting code
397 with the 'compile' commands.
399 set debug separate-debug-file
400 show debug separate-debug-file
401 Control the display of debug output about separate debug file search.
403 set dump-excluded-mappings
404 show dump-excluded-mappings
405 Control whether mappings marked with the VM_DONTDUMP flag should be
406 dumped when generating a core file.
409 List the registered selftests.
412 Start the debugged program stopping at the first instruction.
415 Control display of debugging messages related to OpenRISC targets.
417 set|show print type nested-type-limit
418 Set and show the limit of nesting level for nested types that the
419 type printer will show.
421 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
424 * Safer/improved support for debugging with no debug info
426 GDB no longer assumes functions with no debug information return
429 This means that GDB now refuses to call such functions unless you
430 tell it the function's type, by either casting the call to the
431 declared return type, or by casting the function to a function
432 pointer of the right type, and calling that:
434 (gdb) p getenv ("PATH")
435 'getenv' has unknown return type; cast the call to its declared return type
436 (gdb) p (char *) getenv ("PATH")
437 $1 = 0x7fffffffe "/usr/local/bin:/"...
438 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
439 $2 = 0x7fffffffe "/usr/local/bin:/"...
441 Similarly, GDB no longer assumes that global variables with no debug
442 info have type 'int', and refuses to print the variable's value
443 unless you tell it the variable's type:
446 'var' has unknown type; cast it to its declared type
450 * New native configurations
452 FreeBSD/aarch64 aarch64*-*-freebsd*
453 FreeBSD/arm arm*-*-freebsd*
457 FreeBSD/aarch64 aarch64*-*-freebsd*
458 FreeBSD/arm arm*-*-freebsd*
459 OpenRISC ELF or1k*-*-elf
461 * Removed targets and native configurations
463 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
465 *** Changes in GDB 8.0
467 * GDB now supports access to the PKU register on GNU/Linux. The register is
468 added by the Memory Protection Keys for Userspace feature which will be
469 available in future Intel CPUs.
471 * GDB now supports C++11 rvalue references.
475 ** New functions to start, stop and access a running btrace recording.
476 ** Rvalue references are now supported in gdb.Type.
478 * GDB now supports recording and replaying rdrand and rdseed Intel 64
481 * Building GDB and GDBserver now requires a C++11 compiler.
483 For example, GCC 4.8 or later.
485 It is no longer possible to build GDB or GDBserver with a C
486 compiler. The --disable-build-with-cxx configure option has been
489 * Building GDB and GDBserver now requires GNU make >= 3.81.
491 It is no longer supported to build GDB or GDBserver with another
492 implementation of the make program or an earlier version of GNU make.
494 * Native debugging on MS-Windows supports command-line redirection
496 Command-line arguments used for starting programs on MS-Windows can
497 now include redirection symbols supported by native Windows shells,
498 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
499 as "run", "start", and "set args", as well as the corresponding MI
502 * Support for thread names on MS-Windows.
504 GDB now catches and handles the special exception that programs
505 running on MS-Windows use to assign names to threads in the
508 * Support for Java programs compiled with gcj has been removed.
510 * User commands now accept an unlimited number of arguments.
511 Previously, only up to 10 was accepted.
513 * The "eval" command now expands user-defined command arguments.
515 This makes it easier to process a variable number of arguments:
520 eval "print $arg%d", $i
525 * Target descriptions can now describe registers for sparc32 and sparc64.
527 * GDB now supports DWARF version 5 (debug information format).
528 Its .debug_names index is not yet supported.
530 * New native configurations
532 FreeBSD/mips mips*-*-freebsd
536 Synopsys ARC arc*-*-elf32
537 FreeBSD/mips mips*-*-freebsd
539 * Removed targets and native configurations
541 Alpha running FreeBSD alpha*-*-freebsd*
542 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
547 Erases all the flash memory regions reported by the target.
549 maint print arc arc-instruction address
550 Print internal disassembler information about instruction at a given address.
554 set disassembler-options
555 show disassembler-options
556 Controls the passing of target specific information to the disassembler.
557 If it is necessary to specify more than one disassembler option then
558 multiple options can be placed together into a comma separated list.
559 The default value is the empty string. Currently, the only supported
560 targets are ARM, PowerPC and S/390.
565 Erases all the flash memory regions reported by the target. This is
566 equivalent to the CLI command flash-erase.
568 -file-list-shared-libraries
569 List the shared libraries in the program. This is
570 equivalent to the CLI command "info shared".
573 Catchpoints stopping the program when Ada exceptions are
574 handled. This is equivalent to the CLI command "catch handlers".
576 *** Changes in GDB 7.12
578 * GDB and GDBserver now build with a C++ compiler by default.
580 The --enable-build-with-cxx configure option is now enabled by
581 default. One must now explicitly configure with
582 --disable-build-with-cxx in order to build with a C compiler. This
583 option will be removed in a future release.
585 * GDBserver now supports recording btrace without maintaining an active
588 * GDB now supports a negative repeat count in the 'x' command to examine
589 memory backward from the given address. For example:
592 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
593 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
594 (gdb) x/-5i 0x0000000000400580
595 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
596 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
597 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
598 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
599 0x40057b <main(int, char**)+25>:
600 callq 0x400536 <Func1(int, char const*)>
602 * Fortran: Support structures with fields of dynamic types and
603 arrays of dynamic types.
605 * The symbol dumping maintenance commands have new syntax.
606 maint print symbols [-pc address] [--] [filename]
607 maint print symbols [-objfile objfile] [-source source] [--] [filename]
608 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
609 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
610 maint print msymbols [-objfile objfile] [--] [filename]
612 * GDB now supports multibit bitfields and enums in target register
615 * New Python-based convenience function $_as_string(val), which returns
616 the textual representation of a value. This function is especially
617 useful to obtain the text label of an enum value.
619 * Intel MPX bound violation handling.
621 Segmentation faults caused by a Intel MPX boundary violation
622 now display the kind of violation (upper or lower), the memory
623 address accessed and the memory bounds, along with the usual
624 signal received and code location.
628 Program received signal SIGSEGV, Segmentation fault
629 Upper bound violation while accessing address 0x7fffffffc3b3
630 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
631 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
633 * Rust language support.
634 GDB now supports debugging programs written in the Rust programming
635 language. See https://www.rust-lang.org/ for more information about
638 * Support for running interpreters on specified input/output devices
640 GDB now supports a new mechanism that allows frontends to provide
641 fully featured GDB console views, as a better alternative to
642 building such views on top of the "-interpreter-exec console"
643 command. See the new "new-ui" command below. With that command,
644 frontends can now start GDB in the traditional command-line mode
645 running in an embedded terminal emulator widget, and create a
646 separate MI interpreter running on a specified i/o device. In this
647 way, GDB handles line editing, history, tab completion, etc. in the
648 console all by itself, and the GUI uses the separate MI interpreter
649 for its own control and synchronization, invisible to the command
652 * The "catch syscall" command catches groups of related syscalls.
654 The "catch syscall" command now supports catching a group of related
655 syscalls using the 'group:' or 'g:' prefix.
660 skip -gfile file-glob-pattern
661 skip -function function
662 skip -rfunction regular-expression
663 A generalized form of the skip command, with new support for
664 glob-style file names and regular expressions for function names.
665 Additionally, a file spec and a function spec may now be combined.
667 maint info line-table REGEXP
668 Display the contents of GDB's internal line table data struture.
671 Run any GDB unit tests that were compiled in.
674 Start a new user interface instance running INTERP as interpreter,
675 using the TTY file for input/output.
679 ** gdb.Breakpoint objects have a new attribute "pending", which
680 indicates whether the breakpoint is pending.
681 ** Three new breakpoint-related events have been added:
682 gdb.breakpoint_created, gdb.breakpoint_modified, and
683 gdb.breakpoint_deleted.
686 Signal ("set") the given MS-Windows event object. This is used in
687 conjunction with the Windows JIT debugging (AeDebug) support, where
688 the OS suspends a crashing process until a debugger can attach to
689 it. Resuming the crashing process, in order to debug it, is done by
692 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
693 was added in GDBserver, including JIT compiling fast tracepoint's
694 conditional expression bytecode into native code.
696 * Support for various remote target protocols and ROM monitors has
699 target m32rsdi Remote M32R debugging over SDI
700 target mips MIPS remote debugging protocol
701 target pmon PMON ROM monitor
702 target ddb NEC's DDB variant of PMON for Vr4300
703 target rockhopper NEC RockHopper variant of PMON
704 target lsi LSI variant of PMO
706 * Support for tracepoints and fast tracepoints on powerpc-linux,
707 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
708 including JIT compiling fast tracepoint's conditional expression
709 bytecode into native code.
711 * MI async record =record-started now includes the method and format used for
712 recording. For example:
714 =record-started,thread-group="i1",method="btrace",format="bts"
716 * MI async record =thread-selected now includes the frame field. For example:
718 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
722 Andes NDS32 nds32*-*-elf
724 *** Changes in GDB 7.11
726 * GDB now supports debugging kernel-based threads on FreeBSD.
728 * Per-inferior thread numbers
730 Thread numbers are now per inferior instead of global. If you're
731 debugging multiple inferiors, GDB displays thread IDs using a
732 qualified INF_NUM.THR_NUM form. For example:
736 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
737 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
738 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
739 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
741 As consequence, thread numbers as visible in the $_thread
742 convenience variable and in Python's InferiorThread.num attribute
743 are no longer unique between inferiors.
745 GDB now maintains a second thread ID per thread, referred to as the
746 global thread ID, which is the new equivalent of thread numbers in
747 previous releases. See also $_gthread below.
749 For backwards compatibility, MI's thread IDs always refer to global
752 * Commands that accept thread IDs now accept the qualified
753 INF_NUM.THR_NUM form as well. For example:
756 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
759 * In commands that accept a list of thread IDs, you can now refer to
760 all threads of an inferior using a star wildcard. GDB accepts
761 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
762 refer to all threads of the current inferior. For example, "info
765 * You can use "info threads -gid" to display the global thread ID of
768 * The new convenience variable $_gthread holds the global number of
771 * The new convenience variable $_inferior holds the number of the
774 * GDB now displays the ID and name of the thread that hit a breakpoint
775 or received a signal, if your program is multi-threaded. For
778 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
779 Thread 1 "main" received signal SIGINT, Interrupt.
781 * Record btrace now supports non-stop mode.
783 * Support for tracepoints on aarch64-linux was added in GDBserver.
785 * The 'record instruction-history' command now indicates speculative execution
786 when using the Intel Processor Trace recording format.
788 * GDB now allows users to specify explicit locations, bypassing
789 the linespec parser. This feature is also available to GDB/MI
792 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
793 GDB now is able to debug both AArch64 applications and ARM applications
796 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
797 including JIT compiling fast tracepoint's conditional expression bytecode
800 * GDB now supports displaced stepping on AArch64 GNU/Linux.
802 * "info threads", "info inferiors", "info display", "info checkpoints"
803 and "maint info program-spaces" now list the corresponding items in
804 ascending ID order, for consistency with all other "info" commands.
806 * In Ada, the overloads selection menu has been enhanced to display the
807 parameter types and the return types for the matching overloaded subprograms.
811 maint set target-non-stop (on|off|auto)
812 maint show target-non-stop
813 Control whether GDB targets always operate in non-stop mode even if
814 "set non-stop" is "off". The default is "auto", meaning non-stop
815 mode is enabled if supported by the target.
817 maint set bfd-sharing
818 maint show bfd-sharing
819 Control the reuse of bfd objects.
823 Control display of debugging info regarding bfd caching.
827 Control display of debugging info regarding FreeBSD threads.
829 set remote multiprocess-extensions-packet
830 show remote multiprocess-extensions-packet
831 Set/show the use of the remote protocol multiprocess extensions.
833 set remote thread-events
834 show remote thread-events
835 Set/show the use of thread create/exit events.
837 set ada print-signatures on|off
838 show ada print-signatures"
839 Control whether parameter types and return types are displayed in overloads
840 selection menus. It is activaled (@code{on}) by default.
844 Controls the maximum size of memory, in bytes, that GDB will
845 allocate for value contents. Prevents incorrect programs from
846 causing GDB to allocate overly large buffers. Default is 64k.
848 * The "disassemble" command accepts a new modifier: /s.
849 It prints mixed source+disassembly like /m with two differences:
850 - disassembled instructions are now printed in program order, and
851 - and source for all relevant files is now printed.
852 The "/m" option is now considered deprecated: its "source-centric"
853 output hasn't proved useful in practice.
855 * The "record instruction-history" command accepts a new modifier: /s.
856 It behaves exactly like /m and prints mixed source+disassembly.
858 * The "set scheduler-locking" command supports a new mode "replay".
859 It behaves like "off" in record mode and like "on" in replay mode.
861 * Support for various ROM monitors has been removed:
863 target dbug dBUG ROM monitor for Motorola ColdFire
864 target picobug Motorola picobug monitor
865 target dink32 DINK32 ROM monitor for PowerPC
866 target m32r Renesas M32R/D ROM monitor
867 target mon2000 mon2000 ROM monitor
868 target ppcbug PPCBUG ROM monitor for PowerPC
870 * Support for reading/writing memory and extracting values on architectures
871 whose memory is addressable in units of any integral multiple of 8 bits.
874 Allows to break when an Ada exception is handled.
879 Indicates that an exec system call was executed.
881 exec-events feature in qSupported
882 The qSupported packet allows GDB to request support for exec
883 events using the new 'gdbfeature' exec-event, and the qSupported
884 response can contain the corresponding 'stubfeature'. Set and
885 show commands can be used to display whether these features are enabled.
888 Equivalent to interrupting with the ^C character, but works in
891 thread created stop reason (T05 create:...)
892 Indicates that the thread was just created and is stopped at entry.
894 thread exit stop reply (w exitcode;tid)
895 Indicates that the thread has terminated.
898 Enables/disables thread create and exit event reporting. For
899 example, this is used in non-stop mode when GDB stops a set of
900 threads and synchronously waits for the their corresponding stop
901 replies. Without exit events, if one of the threads exits, GDB
902 would hang forever not knowing that it should no longer expect a
903 stop for that same thread.
906 Indicates that there are no resumed threads left in the target (all
907 threads are stopped). The remote stub reports support for this stop
908 reply to GDB's qSupported query.
911 Enables/disables catching syscalls from the inferior process.
912 The remote stub reports support for this packet to GDB's qSupported query.
914 syscall_entry stop reason
915 Indicates that a syscall was just called.
917 syscall_return stop reason
918 Indicates that a syscall just returned.
920 * Extended-remote exec events
922 ** GDB now has support for exec events on extended-remote Linux targets.
923 For such targets with Linux kernels 2.5.46 and later, this enables
924 follow-exec-mode and exec catchpoints.
926 set remote exec-event-feature-packet
927 show remote exec-event-feature-packet
928 Set/show the use of the remote exec event feature.
930 * Thread names in remote protocol
932 The reply to qXfer:threads:read may now include a name attribute for each
935 * Target remote mode fork and exec events
937 ** GDB now has support for fork and exec events on target remote mode
938 Linux targets. For such targets with Linux kernels 2.5.46 and later,
939 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
940 fork and exec catchpoints.
942 * Remote syscall events
944 ** GDB now has support for catch syscall on remote Linux targets,
945 currently enabled on x86/x86_64 architectures.
947 set remote catch-syscall-packet
948 show remote catch-syscall-packet
949 Set/show the use of the remote catch syscall feature.
953 ** The -var-set-format command now accepts the zero-hexadecimal
954 format. It outputs data in hexadecimal format with zero-padding on the
959 ** gdb.InferiorThread objects have a new attribute "global_num",
960 which refers to the thread's global thread ID. The existing
961 "num" attribute now refers to the thread's per-inferior number.
962 See "Per-inferior thread numbers" above.
963 ** gdb.InferiorThread objects have a new attribute "inferior", which
964 is the Inferior object the thread belongs to.
966 *** Changes in GDB 7.10
968 * Support for process record-replay and reverse debugging on aarch64*-linux*
969 targets has been added. GDB now supports recording of A64 instruction set
970 including advance SIMD instructions.
972 * Support for Sun's version of the "stabs" debug file format has been removed.
974 * GDB now honors the content of the file /proc/PID/coredump_filter
975 (PID is the process ID) on GNU/Linux systems. This file can be used
976 to specify the types of memory mappings that will be included in a
977 corefile. For more information, please refer to the manual page of
978 "core(5)". GDB also has a new command: "set use-coredump-filter
979 on|off". It allows to set whether GDB will read the content of the
980 /proc/PID/coredump_filter file when generating a corefile.
982 * The "info os" command on GNU/Linux can now display information on
984 "info os cpus" Listing of all cpus/cores on the system
986 * GDB has two new commands: "set serial parity odd|even|none" and
987 "show serial parity". These allows to set or show parity for the
990 * The "info source" command now displays the producer string if it was
991 present in the debug info. This typically includes the compiler version
992 and may include things like its command line arguments.
994 * The "info dll", an alias of the "info sharedlibrary" command,
995 is now available on all platforms.
997 * Directory names supplied to the "set sysroot" commands may be
998 prefixed with "target:" to tell GDB to access shared libraries from
999 the target system, be it local or remote. This replaces the prefix
1000 "remote:". The default sysroot has been changed from "" to
1001 "target:". "remote:" is automatically converted to "target:" for
1002 backward compatibility.
1004 * The system root specified by "set sysroot" will be prepended to the
1005 filename of the main executable (if reported to GDB as absolute by
1006 the operating system) when starting processes remotely, and when
1007 attaching to already-running local or remote processes.
1009 * GDB now supports automatic location and retrieval of executable
1010 files from remote targets. Remote debugging can now be initiated
1011 using only a "target remote" or "target extended-remote" command
1012 (no "set sysroot" or "file" commands are required). See "New remote
1015 * The "dump" command now supports verilog hex format.
1017 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1019 * On GNU/Linux, GDB and gdbserver are now able to access executable
1020 and shared library files without a "set sysroot" command when
1021 attaching to processes running in different mount namespaces from
1022 the debugger. This makes it possible to attach to processes in
1023 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1024 See "New remote packets" below.
1026 * The "tui reg" command now provides completion for all of the
1027 available register groups, including target specific groups.
1029 * The HISTSIZE environment variable is no longer read when determining
1030 the size of GDB's command history. GDB now instead reads the dedicated
1031 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1032 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1037 ** Memory ports can now be unbuffered.
1041 ** gdb.Objfile objects have a new attribute "username",
1042 which is the name of the objfile as specified by the user,
1043 without, for example, resolving symlinks.
1044 ** You can now write frame unwinders in Python.
1045 ** gdb.Type objects have a new method "optimized_out",
1046 returning optimized out gdb.Value instance of this type.
1047 ** gdb.Value objects have new methods "reference_value" and
1048 "const_value" which return a reference to the value and a
1049 "const" version of the value respectively.
1053 maint print symbol-cache
1054 Print the contents of the symbol cache.
1056 maint print symbol-cache-statistics
1057 Print statistics of symbol cache usage.
1059 maint flush-symbol-cache
1060 Flush the contents of the symbol cache.
1064 Start branch trace recording using Branch Trace Store (BTS) format.
1067 Evaluate expression by using the compiler and print result.
1071 Explicit commands for enabling and disabling tui mode.
1074 set mpx bound on i386 and amd64
1075 Support for bound table investigation on Intel MPX enabled applications.
1079 Start branch trace recording using Intel Processor Trace format.
1082 Print information about branch tracing internals.
1084 maint btrace packet-history
1085 Print the raw branch tracing data.
1087 maint btrace clear-packet-history
1088 Discard the stored raw branch tracing data.
1091 Discard all branch tracing data. It will be fetched and processed
1092 anew by the next "record" command.
1097 Renamed from "set debug dwarf2-die".
1098 show debug dwarf-die
1099 Renamed from "show debug dwarf2-die".
1101 set debug dwarf-read
1102 Renamed from "set debug dwarf2-read".
1103 show debug dwarf-read
1104 Renamed from "show debug dwarf2-read".
1106 maint set dwarf always-disassemble
1107 Renamed from "maint set dwarf2 always-disassemble".
1108 maint show dwarf always-disassemble
1109 Renamed from "maint show dwarf2 always-disassemble".
1111 maint set dwarf max-cache-age
1112 Renamed from "maint set dwarf2 max-cache-age".
1113 maint show dwarf max-cache-age
1114 Renamed from "maint show dwarf2 max-cache-age".
1116 set debug dwarf-line
1117 show debug dwarf-line
1118 Control display of debugging info regarding DWARF line processing.
1121 show max-completions
1122 Set the maximum number of candidates to be considered during
1123 completion. The default value is 200. This limit allows GDB
1124 to avoid generating large completion lists, the computation of
1125 which can cause the debugger to become temporarily unresponsive.
1127 set history remove-duplicates
1128 show history remove-duplicates
1129 Control the removal of duplicate history entries.
1131 maint set symbol-cache-size
1132 maint show symbol-cache-size
1133 Control the size of the symbol cache.
1135 set|show record btrace bts buffer-size
1136 Set and show the size of the ring buffer used for branch tracing in
1138 The obtained size may differ from the requested size. Use "info
1139 record" to see the obtained buffer size.
1141 set debug linux-namespaces
1142 show debug linux-namespaces
1143 Control display of debugging info regarding Linux namespaces.
1145 set|show record btrace pt buffer-size
1146 Set and show the size of the ring buffer used for branch tracing in
1147 Intel Processor Trace format.
1148 The obtained size may differ from the requested size. Use "info
1149 record" to see the obtained buffer size.
1151 maint set|show btrace pt skip-pad
1152 Set and show whether PAD packets are skipped when computing the
1155 * The command 'thread apply all' can now support new option '-ascending'
1156 to call its specified command for all threads in ascending order.
1158 * Python/Guile scripting
1160 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1161 special section named `.debug_gdb_scripts'.
1163 * New remote packets
1165 qXfer:btrace-conf:read
1166 Return the branch trace configuration for the current thread.
1168 Qbtrace-conf:bts:size
1169 Set the requested ring buffer size for branch tracing in BTS format.
1172 Enable Intel Procesor Trace-based branch tracing for the current
1173 process. The remote stub reports support for this packet to GDB's
1176 Qbtrace-conf:pt:size
1177 Set the requested ring buffer size for branch tracing in Intel Processor
1181 Indicates a memory breakpoint instruction was executed, irrespective
1182 of whether it was GDB that planted the breakpoint or the breakpoint
1183 is hardcoded in the program. This is required for correct non-stop
1187 Indicates the target stopped for a hardware breakpoint. This is
1188 required for correct non-stop mode operation.
1191 Return information about files on the remote system.
1193 qXfer:exec-file:read
1194 Return the full absolute name of the file that was executed to
1195 create a process running on the remote system.
1198 Select the filesystem on which vFile: operations with filename
1199 arguments will operate. This is required for GDB to be able to
1200 access files on remote targets where the remote stub does not
1201 share a common filesystem with the inferior(s).
1204 Indicates that a fork system call was executed.
1207 Indicates that a vfork system call was executed.
1209 vforkdone stop reason
1210 Indicates that a vfork child of the specified process has executed
1211 an exec or exit, allowing the vfork parent to resume execution.
1213 fork-events and vfork-events features in qSupported
1214 The qSupported packet allows GDB to request support for fork and
1215 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1216 and the qSupported response can contain the corresponding
1217 'stubfeatures'. Set and show commands can be used to display
1218 whether these features are enabled.
1220 * Extended-remote fork events
1222 ** GDB now has support for fork events on extended-remote Linux
1223 targets. For targets with Linux kernels 2.5.60 and later, this
1224 enables follow-fork-mode and detach-on-fork for both fork and
1225 vfork, as well as fork and vfork catchpoints.
1227 * The info record command now shows the recording format and the
1228 branch tracing configuration for the current thread when using
1229 the btrace record target.
1230 For the BTS format, it shows the ring buffer size.
1232 * GDB now has support for DTrace USDT (Userland Static Defined
1233 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1235 * GDB now supports access to vector registers on S/390 GNU/Linux
1238 * Removed command line options
1240 -xdb HP-UX XDB compatibility mode.
1242 * Removed targets and native configurations
1244 HP/PA running HP-UX hppa*-*-hpux*
1245 Itanium running HP-UX ia64-*-hpux*
1247 * New configure options
1250 This configure option allows the user to build GDB with support for
1251 Intel Processor Trace (default: auto). This requires libipt.
1253 --with-libipt-prefix=PATH
1254 Specify the path to the version of libipt that GDB should use.
1255 $PATH/include should contain the intel-pt.h header and
1256 $PATH/lib should contain the libipt.so library.
1258 *** Changes in GDB 7.9.1
1262 ** Xmethods can now specify a result type.
1264 *** Changes in GDB 7.9
1266 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1270 ** You can now access frame registers from Python scripts.
1271 ** New attribute 'producer' for gdb.Symtab objects.
1272 ** gdb.Objfile objects have a new attribute "progspace",
1273 which is the gdb.Progspace object of the containing program space.
1274 ** gdb.Objfile objects have a new attribute "owner".
1275 ** gdb.Objfile objects have a new attribute "build_id",
1276 which is the build ID generated when the file was built.
1277 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1278 ** A new event "gdb.clear_objfiles" has been added, triggered when
1279 selecting a new file to debug.
1280 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1281 ** New function gdb.lookup_objfile.
1283 New events which are triggered when GDB modifies the state of the
1286 ** gdb.events.inferior_call_pre: Function call is about to be made.
1287 ** gdb.events.inferior_call_post: Function call has just been made.
1288 ** gdb.events.memory_changed: A memory location has been altered.
1289 ** gdb.events.register_changed: A register has been altered.
1291 * New Python-based convenience functions:
1293 ** $_caller_is(name [, number_of_frames])
1294 ** $_caller_matches(regexp [, number_of_frames])
1295 ** $_any_caller_is(name [, number_of_frames])
1296 ** $_any_caller_matches(regexp [, number_of_frames])
1298 * GDB now supports the compilation and injection of source code into
1299 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1300 to compile the source code to object code, and if successful, inject
1301 and execute that code within the current context of the inferior.
1302 Currently the C language is supported. The commands used to
1303 interface with this new feature are:
1305 compile code [-raw|-r] [--] [source code]
1306 compile file [-raw|-r] filename
1310 demangle [-l language] [--] name
1311 Demangle "name" in the specified language, or the current language
1312 if elided. This command is renamed from the "maint demangle" command.
1313 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1314 as "maint demangler-warning".
1316 queue-signal signal-name-or-number
1317 Queue a signal to be delivered to the thread when it is resumed.
1319 add-auto-load-scripts-directory directory
1320 Add entries to the list of directories from which to load auto-loaded
1323 maint print user-registers
1324 List all currently available "user" registers.
1326 compile code [-r|-raw] [--] [source code]
1327 Compile, inject, and execute in the inferior the executable object
1328 code produced by compiling the provided source code.
1330 compile file [-r|-raw] filename
1331 Compile and inject into the inferior the executable object code
1332 produced by compiling the source code stored in the filename
1335 * On resume, GDB now always passes the signal the program had stopped
1336 for to the thread the signal was sent to, even if the user changed
1337 threads before resuming. Previously GDB would often (but not
1338 always) deliver the signal to the thread that happens to be current
1341 * Conversely, the "signal" command now consistently delivers the
1342 requested signal to the current thread. GDB now asks for
1343 confirmation if the program had stopped for a signal and the user
1344 switched threads meanwhile.
1346 * "breakpoint always-inserted" modes "off" and "auto" merged.
1348 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1349 won't remove breakpoints from the target until all threads stop,
1350 even in non-stop mode. The "auto" mode has been removed, and "off"
1351 is now the default mode.
1355 set debug symbol-lookup
1356 show debug symbol-lookup
1357 Control display of debugging info regarding symbol lookup.
1361 ** The -list-thread-groups command outputs an exit-code field for
1362 inferiors that have exited.
1366 MIPS SDE mips*-sde*-elf*
1370 Support for these obsolete configurations has been removed.
1372 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1373 SGI Irix-5.x mips-*-irix5*
1374 SGI Irix-6.x mips-*-irix6*
1375 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1376 VAX running Ultrix vax-*-ultrix*
1378 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1379 and "assf"), have been removed. Use the "sharedlibrary" command, or
1380 its alias "share", instead.
1382 *** Changes in GDB 7.8
1384 * New command line options
1387 This is an alias for the --data-directory option.
1389 * GDB supports printing and modifying of variable length automatic arrays
1390 as specified in ISO C99.
1392 * The ARM simulator now supports instruction level tracing
1393 with or without disassembly.
1397 GDB now has support for scripting using Guile. Whether this is
1398 available is determined at configure time.
1399 Guile version 2.0 or greater is required.
1400 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1402 * New commands (for set/show, see "New options" below)
1406 Invoke CODE by passing it to the Guile interpreter.
1410 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1412 info auto-load guile-scripts [regexp]
1413 Print the list of automatically loaded Guile scripts.
1415 * The source command is now capable of sourcing Guile scripts.
1416 This feature is dependent on the debugger being built with Guile support.
1420 set print symbol-loading (off|brief|full)
1421 show print symbol-loading
1422 Control whether to print informational messages when loading symbol
1423 information for a file. The default is "full", but when debugging
1424 programs with large numbers of shared libraries the amount of output
1425 becomes less useful.
1427 set guile print-stack (none|message|full)
1428 show guile print-stack
1429 Show a stack trace when an error is encountered in a Guile script.
1431 set auto-load guile-scripts (on|off)
1432 show auto-load guile-scripts
1433 Control auto-loading of Guile script files.
1435 maint ada set ignore-descriptive-types (on|off)
1436 maint ada show ignore-descriptive-types
1437 Control whether the debugger should ignore descriptive types in Ada
1438 programs. The default is not to ignore the descriptive types. See
1439 the user manual for more details on descriptive types and the intended
1440 usage of this option.
1442 set auto-connect-native-target
1444 Control whether GDB is allowed to automatically connect to the
1445 native target for the run, attach, etc. commands when not connected
1446 to any target yet. See also "target native" below.
1448 set record btrace replay-memory-access (read-only|read-write)
1449 show record btrace replay-memory-access
1450 Control what memory accesses are allowed during replay.
1452 maint set target-async (on|off)
1453 maint show target-async
1454 This controls whether GDB targets operate in synchronous or
1455 asynchronous mode. Normally the default is asynchronous, if it is
1456 available; but this can be changed to more easily debug problems
1457 occurring only in synchronous mode.
1459 set mi-async (on|off)
1461 Control whether MI asynchronous mode is preferred. This supersedes
1462 "set target-async" of previous GDB versions.
1464 * "set target-async" is deprecated as a CLI option and is now an alias
1465 for "set mi-async" (only puts MI into async mode).
1467 * Background execution commands (e.g., "c&", "s&", etc.) are now
1468 possible ``out of the box'' if the target supports them. Previously
1469 the user would need to explicitly enable the possibility with the
1470 "set target-async on" command.
1472 * New features in the GDB remote stub, GDBserver
1474 ** New option --debug-format=option1[,option2,...] allows one to add
1475 additional text to each output. At present only timestamps
1476 are supported: --debug-format=timestamps.
1477 Timestamps can also be turned on with the
1478 "monitor set debug-format timestamps" command from GDB.
1480 * The 'record instruction-history' command now starts counting instructions
1481 at one. This also affects the instruction ranges reported by the
1482 'record function-call-history' command when given the /i modifier.
1484 * The command 'record function-call-history' supports a new modifier '/c' to
1485 indent the function names based on their call stack depth.
1486 The fields for the '/i' and '/l' modifier have been reordered.
1487 The source line range is now prefixed with 'at'.
1488 The instruction range is now prefixed with 'inst'.
1489 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1490 "record instruction-history" and "list" commands.
1492 * The ranges given as arguments to the 'record function-call-history' and
1493 'record instruction-history' commands are now inclusive.
1495 * The btrace record target now supports the 'record goto' command.
1496 For locations inside the execution trace, the back trace is computed
1497 based on the information stored in the execution trace.
1499 * The btrace record target supports limited reverse execution and replay.
1500 The target does not record data and therefore does not allow reading
1501 memory or registers.
1503 * The "catch syscall" command now works on s390*-linux* targets.
1505 * The "compare-sections" command is no longer specific to target
1506 remote. It now works with all targets.
1508 * All native targets are now consistently called "native".
1509 Consequently, the "target child", "target GNU", "target djgpp",
1510 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1511 commands have been replaced with "target native". The QNX/NTO port
1512 leaves the "procfs" target in place and adds a "native" target for
1513 consistency with other ports. The impact on users should be minimal
1514 as these commands previously either throwed an error, or were
1515 no-ops. The target's name is visible in the output of the following
1516 commands: "help target", "info target", "info files", "maint print
1519 * The "target native" command now connects to the native target. This
1520 can be used to launch native programs even when "set
1521 auto-connect-native-target" is set to off.
1523 * GDB now supports access to Intel MPX registers on GNU/Linux.
1525 * Support for Intel AVX-512 registers on GNU/Linux.
1526 Support displaying and modifying Intel AVX-512 registers
1527 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1529 * New remote packets
1531 qXfer:btrace:read's annex
1532 The qXfer:btrace:read packet supports a new annex 'delta' to read
1533 branch trace incrementally.
1537 ** Valid Python operations on gdb.Value objects representing
1538 structs/classes invoke the corresponding overloaded operators if
1540 ** New `Xmethods' feature in the Python API. Xmethods are
1541 additional methods or replacements for existing methods of a C++
1542 class. This feature is useful for those cases where a method
1543 defined in C++ source code could be inlined or optimized out by
1544 the compiler, making it unavailable to GDB.
1547 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1549 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1550 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1551 its alias "share", instead.
1553 * The commands "set remotebaud" and "show remotebaud" are no longer
1554 supported. Use "set serial baud" and "show serial baud" (respectively)
1559 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1560 target-async". The latter is left as a deprecated alias of the
1561 former for backward compatibility. If the target supports it,
1562 CLI background execution commands are now always possible by
1563 default, independently of whether the frontend stated a
1564 preference for asynchronous execution with "-gdb-set mi-async".
1565 Previously "-gdb-set target-async off" affected both MI execution
1566 commands and CLI execution commands.
1568 *** Changes in GDB 7.7
1570 * Improved support for process record-replay and reverse debugging on
1571 arm*-linux* targets. Support for thumb32 and syscall instruction
1572 recording has been added.
1574 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1576 * GDB now supports Fission DWP file format version 2.
1577 http://gcc.gnu.org/wiki/DebugFission
1579 * New convenience function "$_isvoid", to check whether an expression
1580 is void. A void expression is an expression where the type of the
1581 result is "void". For example, some convenience variables may be
1582 "void" when evaluated (e.g., "$_exitcode" before the execution of
1583 the program being debugged; or an undefined convenience variable).
1584 Another example, when calling a function whose return type is
1587 * The "maintenance print objfiles" command now takes an optional regexp.
1589 * The "catch syscall" command now works on arm*-linux* targets.
1591 * GDB now consistently shows "<not saved>" when printing values of
1592 registers the debug info indicates have not been saved in the frame
1593 and there's nowhere to retrieve them from
1594 (callee-saved/call-clobbered registers):
1599 (gdb) info registers rax
1602 Before, the former would print "<optimized out>", and the latter
1603 "*value not available*".
1605 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1610 ** Frame filters and frame decorators have been added.
1611 ** Temporary breakpoints are now supported.
1612 ** Line tables representation has been added.
1613 ** New attribute 'parent_type' for gdb.Field objects.
1614 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1615 ** New attribute 'name' for gdb.Type objects.
1619 Nios II ELF nios2*-*-elf
1620 Nios II GNU/Linux nios2*-*-linux
1621 Texas Instruments MSP430 msp430*-*-elf
1623 * Removed native configurations
1625 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1626 been removed. ELF variants of these configurations are kept supported.
1628 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1629 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1630 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1631 i[34567]86-*-openbsd3.[0-3]
1632 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1633 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1634 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1638 Like "catch throw", but catches a re-thrown exception.
1639 maint check-psymtabs
1640 Renamed from old "maint check-symtabs".
1642 Perform consistency checks on symtabs.
1643 maint expand-symtabs
1644 Expand symtabs matching an optional regexp.
1647 Display the details of GDB configure-time options.
1649 maint set|show per-command
1650 maint set|show per-command space
1651 maint set|show per-command time
1652 maint set|show per-command symtab
1653 Enable display of per-command gdb resource usage.
1655 remove-symbol-file FILENAME
1656 remove-symbol-file -a ADDRESS
1657 Remove a symbol file added via add-symbol-file. The file to remove
1658 can be identified by its filename or by an address that lies within
1659 the boundaries of this symbol file in memory.
1662 info exceptions REGEXP
1663 Display the list of Ada exceptions defined in the program being
1664 debugged. If provided, only the exceptions whose names match REGEXP
1669 set debug symfile off|on
1671 Control display of debugging info regarding reading symbol files and
1672 symbol tables within those files
1674 set print raw frame-arguments
1675 show print raw frame-arguments
1676 Set/show whether to print frame arguments in raw mode,
1677 disregarding any defined pretty-printers.
1679 set remote trace-status-packet
1680 show remote trace-status-packet
1681 Set/show the use of remote protocol qTStatus packet.
1685 Control display of debugging messages related to Nios II targets.
1689 Control whether target-assisted range stepping is enabled.
1691 set startup-with-shell
1692 show startup-with-shell
1693 Specifies whether Unix child processes are started via a shell or
1698 Use the target memory cache for accesses to the code segment. This
1699 improves performance of remote debugging (particularly disassembly).
1701 * You can now use a literal value 'unlimited' for options that
1702 interpret 0 or -1 as meaning "unlimited". E.g., "set
1703 trace-buffer-size unlimited" is now an alias for "set
1704 trace-buffer-size -1" and "set height unlimited" is now an alias for
1707 * The "set debug symtab-create" debugging option of GDB has been changed to
1708 accept a verbosity level. 0 means "off", 1 provides basic debugging
1709 output, and values of 2 or greater provides more verbose output.
1711 * New command-line options
1713 Display the details of GDB configure-time options.
1715 * The command 'tsave' can now support new option '-ctf' to save trace
1716 buffer in Common Trace Format.
1718 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1721 * GDB now implements the the C++ 'typeid' operator.
1723 * The new convenience variable $_exception holds the exception being
1724 thrown or caught at an exception-related catchpoint.
1726 * The exception-related catchpoints, like "catch throw", now accept a
1727 regular expression which can be used to filter exceptions by type.
1729 * The new convenience variable $_exitsignal is automatically set to
1730 the terminating signal number when the program being debugged dies
1731 due to an uncaught signal.
1735 ** All MI commands now accept an optional "--language" option.
1736 Support for this feature can be verified by using the "-list-features"
1737 command, which should contain "language-option".
1739 ** The new command -info-gdb-mi-command allows the user to determine
1740 whether a GDB/MI command is supported or not.
1742 ** The "^error" result record returned when trying to execute an undefined
1743 GDB/MI command now provides a variable named "code" whose content is the
1744 "undefined-command" error code. Support for this feature can be verified
1745 by using the "-list-features" command, which should contain
1746 "undefined-command-error-code".
1748 ** The -trace-save MI command can optionally save trace buffer in Common
1751 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1753 ** The command -data-list-register-values now accepts an optional
1754 "--skip-unavailable" option. When used, only the available registers
1757 ** The new command -trace-frame-collected dumps collected variables,
1758 computed expressions, tvars, memory and registers in a traceframe.
1760 ** The commands -stack-list-locals, -stack-list-arguments and
1761 -stack-list-variables now accept an option "--skip-unavailable".
1762 When used, only the available locals or arguments are displayed.
1764 ** The -exec-run command now accepts an optional "--start" option.
1765 When used, the command follows the same semantics as the "start"
1766 command, stopping the program's execution at the start of its
1767 main subprogram. Support for this feature can be verified using
1768 the "-list-features" command, which should contain
1769 "exec-run-start-option".
1771 ** The new commands -catch-assert and -catch-exceptions insert
1772 catchpoints stopping the program when Ada exceptions are raised.
1774 ** The new command -info-ada-exceptions provides the equivalent of
1775 the new "info exceptions" command.
1777 * New system-wide configuration scripts
1778 A GDB installation now provides scripts suitable for use as system-wide
1779 configuration scripts for the following systems:
1783 * GDB now supports target-assigned range stepping with remote targets.
1784 This improves the performance of stepping source lines by reducing
1785 the number of control packets from/to GDB. See "New remote packets"
1788 * GDB now understands the element 'tvar' in the XML traceframe info.
1789 It has the id of the collected trace state variables.
1791 * On S/390 targets that provide the transactional-execution feature,
1792 the program interruption transaction diagnostic block (TDB) is now
1793 represented as a number of additional "registers" in GDB.
1795 * New remote packets
1799 The vCont packet supports a new 'r' action, that tells the remote
1800 stub to step through an address range itself, without GDB
1801 involvemement at each single-step.
1803 qXfer:libraries-svr4:read's annex
1804 The previously unused annex of the qXfer:libraries-svr4:read packet
1805 is now used to support passing an argument list. The remote stub
1806 reports support for this argument list to GDB's qSupported query.
1807 The defined arguments are "start" and "prev", used to reduce work
1808 necessary for library list updating, resulting in significant
1811 * New features in the GDB remote stub, GDBserver
1813 ** GDBserver now supports target-assisted range stepping. Currently
1814 enabled on x86/x86_64 GNU/Linux targets.
1816 ** GDBserver now adds element 'tvar' in the XML in the reply to
1817 'qXfer:traceframe-info:read'. It has the id of the collected
1818 trace state variables.
1820 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1823 * New 'z' formatter for printing and examining memory, this displays the
1824 value as hexadecimal zero padded on the left to the size of the type.
1826 * GDB can now use Windows x64 unwinding data.
1828 * The "set remotebaud" command has been replaced by "set serial baud".
1829 Similarly, "show remotebaud" has been replaced by "show serial baud".
1830 The "set remotebaud" and "show remotebaud" commands are still available
1831 to provide backward compatibility with older versions of GDB.
1833 *** Changes in GDB 7.6
1835 * Target record has been renamed to record-full.
1836 Record/replay is now enabled with the "record full" command.
1837 This also affects settings that are associated with full record/replay
1838 that have been moved from "set/show record" to "set/show record full":
1840 set|show record full insn-number-max
1841 set|show record full stop-at-limit
1842 set|show record full memory-query
1844 * A new record target "record-btrace" has been added. The new target
1845 uses hardware support to record the control-flow of a process. It
1846 does not support replaying the execution, but it implements the
1847 below new commands for investigating the recorded execution log.
1848 This new recording method can be enabled using:
1852 The "record-btrace" target is only available on Intel Atom processors
1853 and requires a Linux kernel 2.6.32 or later.
1855 * Two new commands have been added for record/replay to give information
1856 about the recorded execution without having to replay the execution.
1857 The commands are only supported by "record btrace".
1859 record instruction-history prints the execution history at
1860 instruction granularity
1862 record function-call-history prints the execution history at
1863 function granularity
1865 * New native configurations
1867 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1868 FreeBSD/powerpc powerpc*-*-freebsd
1869 x86_64/Cygwin x86_64-*-cygwin*
1870 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1874 ARM AArch64 aarch64*-*-elf
1875 ARM AArch64 GNU/Linux aarch64*-*-linux
1876 Lynx 178 PowerPC powerpc-*-lynx*178
1877 x86_64/Cygwin x86_64-*-cygwin*
1878 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1880 * If the configured location of system.gdbinit file (as given by the
1881 --with-system-gdbinit option at configure time) is in the
1882 data-directory (as specified by --with-gdb-datadir at configure
1883 time) or in one of its subdirectories, then GDB will look for the
1884 system-wide init file in the directory specified by the
1885 --data-directory command-line option.
1887 * New command line options:
1889 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1890 other initialization files, unlike -nx which disables all of them.
1892 * Removed command line options
1894 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1897 * The 'ptype' and 'whatis' commands now accept an argument to control
1900 * 'info proc' now works on some core files.
1904 ** Vectors can be created with gdb.Type.vector.
1906 ** Python's atexit.register now works in GDB.
1908 ** Types can be pretty-printed via a Python API.
1910 ** Python 3 is now supported (in addition to Python 2.4 or later)
1912 ** New class gdb.Architecture exposes GDB's internal representation
1913 of architecture in the Python API.
1915 ** New method Frame.architecture returns the gdb.Architecture object
1916 corresponding to the frame's architecture.
1918 * New Python-based convenience functions:
1920 ** $_memeq(buf1, buf2, length)
1921 ** $_streq(str1, str2)
1923 ** $_regex(str, regex)
1925 * The 'cd' command now defaults to using '~' (the home directory) if not
1928 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1929 default for GCC since November 2000.
1931 * The command 'forward-search' can now be abbreviated as 'fo'.
1933 * The command 'info tracepoints' can now display 'installed on target'
1934 or 'not installed on target' for each non-pending location of tracepoint.
1936 * New configure options
1938 --enable-libmcheck/--disable-libmcheck
1939 By default, development versions are built with -lmcheck on hosts
1940 that support it, in order to help track memory corruption issues.
1941 Release versions, on the other hand, are built without -lmcheck
1942 by default. The --enable-libmcheck/--disable-libmcheck configure
1943 options allow the user to override that default.
1944 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1945 This configure option allows the user to build GDB with
1946 libbabeltrace using which GDB can read Common Trace Format data.
1948 * New commands (for set/show, see "New options" below)
1951 Catch signals. This is similar to "handle", but allows commands and
1952 conditions to be attached.
1955 List the BFDs known to GDB.
1957 python-interactive [command]
1959 Start a Python interactive prompt, or evaluate the optional command
1960 and print the result of expressions.
1963 "py" is a new alias for "python".
1965 enable type-printer [name]...
1966 disable type-printer [name]...
1967 Enable or disable type printers.
1971 ** For the Renesas Super-H architecture, the "regs" command has been removed
1972 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1977 set print type methods (on|off)
1978 show print type methods
1979 Control whether method declarations are displayed by "ptype".
1980 The default is to show them.
1982 set print type typedefs (on|off)
1983 show print type typedefs
1984 Control whether typedef definitions are displayed by "ptype".
1985 The default is to show them.
1987 set filename-display basename|relative|absolute
1988 show filename-display
1989 Control the way in which filenames is displayed.
1990 The default is "relative", which preserves previous behavior.
1992 set trace-buffer-size
1993 show trace-buffer-size
1994 Request target to change the size of trace buffer.
1996 set remote trace-buffer-size-packet auto|on|off
1997 show remote trace-buffer-size-packet
1998 Control the use of the remote protocol `QTBuffer:size' packet.
2002 Control display of debugging messages related to ARM AArch64.
2005 set debug coff-pe-read
2006 show debug coff-pe-read
2007 Control display of debugging messages related to reading of COFF/PE
2012 Control display of debugging messages related to Mach-O symbols
2015 set debug notification
2016 show debug notification
2017 Control display of debugging info for async remote notification.
2021 ** Command parameter changes are now notified using new async record
2022 "=cmd-param-changed".
2023 ** Trace frame changes caused by command "tfind" are now notified using
2024 new async record "=traceframe-changed".
2025 ** The creation, deletion and modification of trace state variables
2026 are now notified using new async records "=tsv-created",
2027 "=tsv-deleted" and "=tsv-modified".
2028 ** The start and stop of process record are now notified using new
2029 async record "=record-started" and "=record-stopped".
2030 ** Memory changes are now notified using new async record
2032 ** The data-disassemble command response will include a "fullname" field
2033 containing the absolute file name when source has been requested.
2034 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2035 command, to allow pattern filling of memory areas.
2036 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2037 library load/unload events.
2038 ** The response to breakpoint commands and breakpoint async records
2039 includes an "installed" field containing a boolean state about each
2040 non-pending tracepoint location is whether installed on target or not.
2041 ** Output of the "-trace-status" command includes a "trace-file" field
2042 containing the name of the trace file being examined. This field is
2043 optional, and only present when examining a trace file.
2044 ** The "fullname" field is now always present along with the "file" field,
2045 even if the file cannot be found by GDB.
2047 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2048 You must have the LZMA library available when configuring GDB for this
2049 feature to be enabled. For more information, see:
2050 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2052 * New remote packets
2055 Set the size of trace buffer. The remote stub reports support for this
2056 packet to gdb's qSupported query.
2059 Enable Branch Trace Store (BTS)-based branch tracing for the current
2060 thread. The remote stub reports support for this packet to gdb's
2064 Disable branch tracing for the current thread. The remote stub reports
2065 support for this packet to gdb's qSupported query.
2068 Read the traced branches for the current thread. The remote stub
2069 reports support for this packet to gdb's qSupported query.
2071 *** Changes in GDB 7.5
2073 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2074 for more x32 ABI info.
2076 * GDB now supports access to MIPS DSP registers on Linux targets.
2078 * GDB now supports debugging microMIPS binaries.
2080 * The "info os" command on GNU/Linux can now display information on
2081 several new classes of objects managed by the operating system:
2082 "info os procgroups" lists process groups
2083 "info os files" lists file descriptors
2084 "info os sockets" lists internet-domain sockets
2085 "info os shm" lists shared-memory regions
2086 "info os semaphores" lists semaphores
2087 "info os msg" lists message queues
2088 "info os modules" lists loaded kernel modules
2090 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2091 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2092 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2093 options and inspect the probe arguments using the new $_probe_arg family
2094 of convenience variables. You can obtain more information about SystemTap
2095 in <http://sourceware.org/systemtap/>.
2097 * GDB now supports reversible debugging on ARM, it allows you to
2098 debug basic ARM and THUMB instructions, and provides
2099 record/replay support.
2101 * The option "symbol-reloading" has been deleted as it is no longer used.
2105 ** GDB commands implemented in Python can now be put in command class
2108 ** The "maint set python print-stack on|off" is now deleted.
2110 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2111 apply "flag enum"-style pretty-printing to any enum.
2113 ** gdb.lookup_symbol can now work when there is no current frame.
2115 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2116 the source at which the symbol was defined.
2118 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2119 method 'value'. The former indicates whether the symbol needs a
2120 frame in order to compute its value, and the latter computes the
2123 ** A new method 'referenced_value' on gdb.Value objects which can
2124 dereference pointer as well as C++ reference values.
2126 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2127 which return the global and static blocks (as gdb.Block objects),
2128 of the underlying symbol table, respectively.
2130 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2131 object associated with a PC value.
2133 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2134 of the address range occupied by code for the current source line.
2136 * Go language support.
2137 GDB now supports debugging programs written in the Go programming
2140 * GDBserver now supports stdio connections.
2141 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2143 * The binary "gdbtui" can no longer be built or installed.
2144 Use "gdb -tui" instead.
2146 * GDB will now print "flag" enums specially. A flag enum is one where
2147 all the enumerator values have no bits in common when pairwise
2148 "and"ed. When printing a value whose type is a flag enum, GDB will
2149 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2150 (gdb) print (enum E) 3
2153 * The filename part of a linespec will now match trailing components
2154 of a source file name. For example, "break gcc/expr.c:1000" will
2155 now set a breakpoint in build/gcc/expr.c, but not
2156 build/libcpp/expr.c.
2158 * The "info proc" and "generate-core-file" commands will now also
2159 work on remote targets connected to GDBserver on Linux.
2161 * The command "info catch" has been removed. It has been disabled
2162 since December 2007.
2164 * The "catch exception" and "catch assert" commands now accept
2165 a condition at the end of the command, much like the "break"
2166 command does. For instance:
2168 (gdb) catch exception Constraint_Error if Barrier = True
2170 Previously, it was possible to add a condition to such catchpoints,
2171 but it had to be done as a second step, after the catchpoint had been
2172 created, using the "condition" command.
2174 * The "info static-tracepoint-marker" command will now also work on
2175 native Linux targets with in-process agent.
2177 * GDB can now set breakpoints on inlined functions.
2179 * The .gdb_index section has been updated to include symbols for
2180 inlined functions. GDB will ignore older .gdb_index sections by
2181 default, which could cause symbol files to be loaded more slowly
2182 until their .gdb_index sections can be recreated. The new command
2183 "set use-deprecated-index-sections on" will cause GDB to use any older
2184 .gdb_index sections it finds. This will restore performance, but the
2185 ability to set breakpoints on inlined functions will be lost in symbol
2186 files with older .gdb_index sections.
2188 The .gdb_index section has also been updated to record more information
2189 about each symbol. This speeds up the "info variables", "info functions"
2190 and "info types" commands when used with programs having the .gdb_index
2191 section, as well as speeding up debugging with shared libraries using
2192 the .gdb_index section.
2194 * Ada support for GDB/MI Variable Objects has been added.
2196 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2201 ** New command -info-os is the MI equivalent of "info os".
2203 ** Output logs ("set logging" and related) now include MI output.
2207 ** "set use-deprecated-index-sections on|off"
2208 "show use-deprecated-index-sections on|off"
2209 Controls the use of deprecated .gdb_index sections.
2211 ** "catch load" and "catch unload" can be used to stop when a shared
2212 library is loaded or unloaded, respectively.
2214 ** "enable count" can be used to auto-disable a breakpoint after
2217 ** "info vtbl" can be used to show the virtual method tables for
2218 C++ and Java objects.
2220 ** "explore" and its sub commands "explore value" and "explore type"
2221 can be used to recursively explore values and types of
2222 expressions. These commands are available only if GDB is
2223 configured with '--with-python'.
2225 ** "info auto-load" shows status of all kinds of auto-loaded files,
2226 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2227 sequences of commands files, "info auto-load python-scripts"
2228 shows status of auto-loading Python script files,
2229 "info auto-load local-gdbinit" shows status of loading init file
2230 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2231 status of inferior specific thread debugging shared library loading.
2233 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2234 and "show auto-load-scripts" commands have been deprecated, use their
2235 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2236 and "show auto-load python-scripts" counterparts instead.
2238 ** "dprintf location,format,args..." creates a dynamic printf, which
2239 is basically a breakpoint that does a printf and immediately
2240 resumes your program's execution, so it is like a printf that you
2241 can insert dynamically at runtime instead of at compiletime.
2243 ** "set print symbol"
2245 Controls whether GDB attempts to display the symbol, if any,
2246 corresponding to addresses it prints. This defaults to "on", but
2247 you can set it to "off" to restore GDB's previous behavior.
2249 * Deprecated commands
2251 ** For the Renesas Super-H architecture, the "regs" command has been
2252 deprecated, and "info all-registers" should be used instead.
2256 Renesas RL78 rl78-*-elf
2257 HP OpenVMS ia64 ia64-hp-openvms*
2259 * GDBserver supports evaluation of breakpoint conditions. When
2260 support is advertised by GDBserver, GDB may be told to send the
2261 breakpoint conditions in bytecode form to GDBserver. GDBserver
2262 will only report the breakpoint trigger to GDB when its condition
2267 set mips compression
2268 show mips compression
2269 Select the compressed ISA encoding used in functions that have no symbol
2270 information available. The encoding can be set to either of:
2273 and is updated automatically from ELF file flags if available.
2275 set breakpoint condition-evaluation
2276 show breakpoint condition-evaluation
2277 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2278 GDBserver ("target"). Default option "auto" chooses the most efficient
2280 This option can improve debugger efficiency depending on the speed of the
2284 Disable auto-loading globally.
2287 Show auto-loading setting of all kinds of auto-loaded files.
2289 set auto-load gdb-scripts on|off
2290 show auto-load gdb-scripts
2291 Control auto-loading of GDB canned sequences of commands files.
2293 set auto-load python-scripts on|off
2294 show auto-load python-scripts
2295 Control auto-loading of Python script files.
2297 set auto-load local-gdbinit on|off
2298 show auto-load local-gdbinit
2299 Control loading of init file (.gdbinit) from current directory.
2301 set auto-load libthread-db on|off
2302 show auto-load libthread-db
2303 Control auto-loading of inferior specific thread debugging shared library.
2305 set auto-load scripts-directory <dir1>[:<dir2>...]
2306 show auto-load scripts-directory
2307 Set a list of directories from which to load auto-loaded scripts.
2308 Automatically loaded Python scripts and GDB scripts are located in one
2309 of the directories listed by this option.
2310 The delimiter (':' above) may differ according to the host platform.
2312 set auto-load safe-path <dir1>[:<dir2>...]
2313 show auto-load safe-path
2314 Set a list of directories from which it is safe to auto-load files.
2315 The delimiter (':' above) may differ according to the host platform.
2317 set debug auto-load on|off
2318 show debug auto-load
2319 Control display of debugging info for auto-loading the files above.
2321 set dprintf-style gdb|call|agent
2323 Control the way in which a dynamic printf is performed; "gdb"
2324 requests a GDB printf command, while "call" causes dprintf to call a
2325 function in the inferior. "agent" requests that the target agent
2326 (such as GDBserver) do the printing.
2328 set dprintf-function <expr>
2329 show dprintf-function
2330 set dprintf-channel <expr>
2331 show dprintf-channel
2332 Set the function and optional first argument to the call when using
2333 the "call" style of dynamic printf.
2335 set disconnected-dprintf on|off
2336 show disconnected-dprintf
2337 Control whether agent-style dynamic printfs continue to be in effect
2338 after GDB disconnects.
2340 * New configure options
2342 --with-auto-load-dir
2343 Configure default value for the 'set auto-load scripts-directory'
2344 setting above. It defaults to '$debugdir:$datadir/auto-load',
2345 $debugdir representing global debugging info directories (available
2346 via 'show debug-file-directory') and $datadir representing GDB's data
2347 directory (available via 'show data-directory').
2349 --with-auto-load-safe-path
2350 Configure default value for the 'set auto-load safe-path' setting
2351 above. It defaults to the --with-auto-load-dir setting.
2353 --without-auto-load-safe-path
2354 Set 'set auto-load safe-path' to '/', effectively disabling this
2357 * New remote packets
2359 z0/z1 conditional breakpoints extension
2361 The z0/z1 breakpoint insertion packets have been extended to carry
2362 a list of conditional expressions over to the remote stub depending on the
2363 condition evaluation mode. The use of this extension can be controlled
2364 via the "set remote conditional-breakpoints-packet" command.
2368 Specify the signals which the remote stub may pass to the debugged
2369 program without GDB involvement.
2371 * New command line options
2373 --init-command=FILE, -ix Like --command, -x but execute it
2374 before loading inferior.
2375 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2376 execute it before loading inferior.
2378 *** Changes in GDB 7.4
2380 * GDB now handles ambiguous linespecs more consistently; the existing
2381 FILE:LINE support has been expanded to other types of linespecs. A
2382 breakpoint will now be set on all matching locations in all
2383 inferiors, and locations will be added or removed according to
2386 * GDB now allows you to skip uninteresting functions and files when
2387 stepping with the "skip function" and "skip file" commands.
2389 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2390 and "show remote hardware-watchpoint-length-limit". These allows to
2391 set or show the maximum length limit (in bytes) of a remote
2392 target hardware watchpoint.
2394 This allows e.g. to use "unlimited" hardware watchpoints with the
2395 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2396 watchpoints are slower than real hardware watchpoints but are
2397 significantly faster than gdb software watchpoints.
2401 ** The register_pretty_printer function in module gdb.printing now takes
2402 an optional `replace' argument. If True, the new printer replaces any
2405 ** The "maint set python print-stack on|off" command has been
2406 deprecated and will be deleted in GDB 7.5.
2407 A new command: "set python print-stack none|full|message" has
2408 replaced it. Additionally, the default for "print-stack" is
2409 now "message", which just prints the error message without
2412 ** A prompt substitution hook (prompt_hook) is now available to the
2415 ** A new Python module, gdb.prompt has been added to the GDB Python
2416 modules library. This module provides functionality for
2417 escape sequences in prompts (used by set/show
2418 extended-prompt). These escape sequences are replaced by their
2419 corresponding value.
2421 ** Python commands and convenience-functions located in
2422 'data-directory'/python/gdb/command and
2423 'data-directory'/python/gdb/function are now automatically loaded
2426 ** Blocks now provide four new attributes. global_block and
2427 static_block will return the global and static blocks
2428 respectively. is_static and is_global are boolean attributes
2429 that indicate if the block is one of those two types.
2431 ** Symbols now provide the "type" attribute, the type of the symbol.
2433 ** The "gdb.breakpoint" function has been deprecated in favor of
2436 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2437 of a function. This class is based on the "finish" command
2438 available in the CLI.
2440 ** Type objects for struct and union types now allow access to
2441 the fields using standard Python dictionary (mapping) methods.
2442 For example, "some_type['myfield']" now works, as does
2443 "some_type.items()".
2445 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2448 ** A new function, "deep_items" has been added to the gdb.types
2449 module in the GDB Python modules library. This function returns
2450 an iterator over the fields of a struct or union type. Unlike
2451 the standard Python "iteritems" method, it will recursively traverse
2452 any anonymous fields.
2456 ** "*stopped" events can report several new "reason"s, such as
2459 ** Breakpoint changes are now notified using new async records, like
2460 "=breakpoint-modified".
2462 ** New command -ada-task-info.
2464 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2465 $sdir specifies the default system locations of shared libraries.
2466 $pdir specifies the directory where the libpthread used by the application
2469 GDB no longer looks in $sdir and $pdir after it has searched the directories
2470 mentioned in libthread-db-search-path. If you want to search those
2471 directories, they must be specified in libthread-db-search-path.
2472 The default value of libthread-db-search-path on GNU/Linux and Solaris
2473 systems is now "$sdir:$pdir".
2475 $pdir is not supported by gdbserver, it is currently ignored.
2476 $sdir is supported by gdbserver.
2478 * New configure option --with-iconv-bin.
2479 When using the internationalization support like the one in the GNU C
2480 library, GDB will invoke the "iconv" program to get a list of supported
2481 character sets. If this program lives in a non-standard location, one can
2482 use this option to specify where to find it.
2484 * When natively debugging programs on PowerPC BookE processors running
2485 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2486 watchpoints, which specify a mask in addition to an address to watch.
2487 The mask specifies that some bits of an address (the bits which are
2488 reset in the mask) should be ignored when matching the address accessed
2489 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2490 section in the user manual for more details.
2492 * The new option --once causes GDBserver to stop listening for connections once
2493 the first connection is made. The listening port used by GDBserver will
2494 become available after that.
2496 * New commands "info macros" and "alias" have been added.
2498 * New function parameters suffix @entry specifies value of function parameter
2499 at the time the function got called. Entry values are available only since
2505 "!" is now an alias of the "shell" command.
2506 Note that no space is needed between "!" and SHELL COMMAND.
2510 watch EXPRESSION mask MASK_VALUE
2511 The watch command now supports the mask argument which allows creation
2512 of masked watchpoints, if the current architecture supports this feature.
2514 info auto-load-scripts [REGEXP]
2515 This command was formerly named "maintenance print section-scripts".
2516 It is now generally useful and is no longer a maintenance-only command.
2518 info macro [-all] [--] MACRO
2519 The info macro command has new options `-all' and `--'. The first for
2520 printing all definitions of a macro. The second for explicitly specifying
2521 the end of arguments and the beginning of the macro name in case the macro
2522 name starts with a hyphen.
2524 collect[/s] EXPRESSIONS
2525 The tracepoint collect command now takes an optional modifier "/s"
2526 that directs it to dereference pointer-to-character types and
2527 collect the bytes of memory up to a zero byte. The behavior is
2528 similar to what you see when you use the regular print command on a
2529 string. An optional integer following the "/s" sets a bound on the
2530 number of bytes that will be collected.
2533 The trace start command now interprets any supplied arguments as a
2534 note to be recorded with the trace run, with an effect similar to
2535 setting the variable trace-notes.
2538 The trace stop command now interprets any arguments as a note to be
2539 mentioned along with the tstatus report that the trace was stopped
2540 with a command. The effect is similar to setting the variable
2543 * Tracepoints can now be enabled and disabled at any time after a trace
2544 experiment has been started using the standard "enable" and "disable"
2545 commands. It is now possible to start a trace experiment with no enabled
2546 tracepoints; GDB will display a warning, but will allow the experiment to
2547 begin, assuming that tracepoints will be enabled as needed while the trace
2550 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2551 locations with 4-byte instructions, when they were previously
2552 limited to locations with instructions of 5 bytes or longer.
2556 set debug dwarf2-read
2557 show debug dwarf2-read
2558 Turns on or off display of debugging messages related to reading
2559 DWARF debug info. The default is off.
2561 set debug symtab-create
2562 show debug symtab-create
2563 Turns on or off display of debugging messages related to symbol table
2564 creation. The default is off.
2567 show extended-prompt
2568 Set the GDB prompt, and allow escape sequences to be inserted to
2569 display miscellaneous information (see 'help set extended-prompt'
2570 for the list of sequences). This prompt (and any information
2571 accessed through the escape sequences) is updated every time the
2572 prompt is displayed.
2574 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2575 show print entry-values
2576 Set printing of frame argument values at function entry. In some cases
2577 GDB can determine the value of function argument which was passed by the
2578 function caller, even if the value was modified inside the called function.
2580 set debug entry-values
2581 show debug entry-values
2582 Control display of debugging info for determining frame argument values at
2583 function entry and virtual tail call frames.
2585 set basenames-may-differ
2586 show basenames-may-differ
2587 Set whether a source file may have multiple base names.
2588 (A "base name" is the name of a file with the directory part removed.
2589 Example: The base name of "/home/user/hello.c" is "hello.c".)
2590 If set, GDB will canonicalize file names (e.g., expand symlinks)
2591 before comparing them. Canonicalization is an expensive operation,
2592 but it allows the same file be known by more than one base name.
2593 If not set (the default), all source files are assumed to have just
2594 one base name, and gdb will do file name comparisons more efficiently.
2600 Set a user name and notes for the current and any future trace runs.
2601 This is useful for long-running and/or disconnected traces, to
2602 inform others (or yourself) as to who is running the trace, supply
2603 contact information, or otherwise explain what is going on.
2605 set trace-stop-notes
2606 show trace-stop-notes
2607 Set a note attached to the trace run, that is displayed when the
2608 trace has been stopped by a tstop command. This is useful for
2609 instance as an explanation, if you are stopping a trace run that was
2610 started by someone else.
2612 * New remote packets
2616 Dynamically enable a tracepoint in a started trace experiment.
2620 Dynamically disable a tracepoint in a started trace experiment.
2624 Set the user and notes of the trace run.
2628 Query the current status of a tracepoint.
2632 Query the minimum length of instruction at which a fast tracepoint may
2635 * Dcache size (number of lines) and line-size are now runtime-configurable
2636 via "set dcache line" and "set dcache line-size" commands.
2640 Texas Instruments TMS320C6x tic6x-*-*
2644 Renesas RL78 rl78-*-elf
2646 *** Changes in GDB 7.3.1
2648 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2650 *** Changes in GDB 7.3
2652 * GDB has a new command: "thread find [REGEXP]".
2653 It finds the thread id whose name, target id, or thread extra info
2654 matches the given regular expression.
2656 * The "catch syscall" command now works on mips*-linux* targets.
2658 * The -data-disassemble MI command now supports modes 2 and 3 for
2659 dumping the instruction opcodes.
2661 * New command line options
2663 -data-directory DIR Specify DIR as the "data-directory".
2664 This is mostly for testing purposes.
2666 * The "maint set python auto-load on|off" command has been renamed to
2667 "set auto-load-scripts on|off".
2669 * GDB has a new command: "set directories".
2670 It is like the "dir" command except that it replaces the
2671 source path list instead of augmenting it.
2673 * GDB now understands thread names.
2675 On GNU/Linux, "info threads" will display the thread name as set by
2676 prctl or pthread_setname_np.
2678 There is also a new command, "thread name", which can be used to
2679 assign a name internally for GDB to display.
2682 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2683 has been integrated into GDB.
2687 ** The function gdb.Write now accepts an optional keyword 'stream'.
2688 This keyword, when provided, will direct the output to either
2689 stdout, stderr, or GDB's logging output.
2691 ** Parameters can now be be sub-classed in Python, and in particular
2692 you may implement the get_set_doc and get_show_doc functions.
2693 This improves how Parameter set/show documentation is processed
2694 and allows for more dynamic content.
2696 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2697 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2698 have an is_valid method.
2700 ** Breakpoints can now be sub-classed in Python, and in particular
2701 you may implement a 'stop' function that is executed each time
2702 the inferior reaches that breakpoint.
2704 ** New function gdb.lookup_global_symbol looks up a global symbol.
2706 ** GDB values in Python are now callable if the value represents a
2707 function. For example, if 'some_value' represents a function that
2708 takes two integer parameters and returns a value, you can call
2709 that function like so:
2711 result = some_value (10,20)
2713 ** Module gdb.types has been added.
2714 It contains a collection of utilities for working with gdb.Types objects:
2715 get_basic_type, has_field, make_enum_dict.
2717 ** Module gdb.printing has been added.
2718 It contains utilities for writing and registering pretty-printers.
2719 New classes: PrettyPrinter, SubPrettyPrinter,
2720 RegexpCollectionPrettyPrinter.
2721 New function: register_pretty_printer.
2723 ** New commands "info pretty-printers", "enable pretty-printer" and
2724 "disable pretty-printer" have been added.
2726 ** gdb.parameter("directories") is now available.
2728 ** New function gdb.newest_frame returns the newest frame in the
2731 ** The gdb.InferiorThread class has a new "name" attribute. This
2732 holds the thread's name.
2734 ** Python Support for Inferior events.
2735 Python scripts can add observers to be notified of events
2736 occurring in the process being debugged.
2737 The following events are currently supported:
2738 - gdb.events.cont Continue event.
2739 - gdb.events.exited Inferior exited event.
2740 - gdb.events.stop Signal received, and Breakpoint hit events.
2744 ** GDB now puts template parameters in scope when debugging in an
2745 instantiation. For example, if you have:
2747 template<int X> int func (void) { return X; }
2749 then if you step into func<5>, "print X" will show "5". This
2750 feature requires proper debuginfo support from the compiler; it
2751 was added to GCC 4.5.
2753 ** The motion commands "next", "finish", "until", and "advance" now
2754 work better when exceptions are thrown. In particular, GDB will
2755 no longer lose control of the inferior; instead, the GDB will
2756 stop the inferior at the point at which the exception is caught.
2757 This functionality requires a change in the exception handling
2758 code that was introduced in GCC 4.5.
2760 * GDB now follows GCC's rules on accessing volatile objects when
2761 reading or writing target state during expression evaluation.
2762 One notable difference to prior behavior is that "print x = 0"
2763 no longer generates a read of x; the value of the assignment is
2764 now always taken directly from the value being assigned.
2766 * GDB now has some support for using labels in the program's source in
2767 linespecs. For instance, you can use "advance label" to continue
2768 execution to a label.
2770 * GDB now has support for reading and writing a new .gdb_index
2771 section. This section holds a fast index of DWARF debugging
2772 information and can be used to greatly speed up GDB startup and
2773 operation. See the documentation for `save gdb-index' for details.
2775 * The "watch" command now accepts an optional "-location" argument.
2776 When used, this causes GDB to watch the memory referred to by the
2777 expression. Such a watchpoint is never deleted due to it going out
2780 * GDB now supports thread debugging of core dumps on GNU/Linux.
2782 GDB now activates thread debugging using the libthread_db library
2783 when debugging GNU/Linux core dumps, similarly to when debugging
2784 live processes. As a result, when debugging a core dump file, GDB
2785 is now able to display pthread_t ids of threads. For example, "info
2786 threads" shows the same output as when debugging the process when it
2787 was live. In earlier releases, you'd see something like this:
2790 * 1 LWP 6780 main () at main.c:10
2792 While now you see this:
2795 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2797 It is also now possible to inspect TLS variables when debugging core
2800 When debugging a core dump generated on a machine other than the one
2801 used to run GDB, you may need to point GDB at the correct
2802 libthread_db library with the "set libthread-db-search-path"
2803 command. See the user manual for more details on this command.
2805 * When natively debugging programs on PowerPC BookE processors running
2806 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2807 which stop execution of the inferior whenever it executes an instruction
2808 at any address within the specified range. See the "PowerPC Embedded"
2809 section in the user manual for more details.
2811 * New features in the GDB remote stub, GDBserver
2813 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2814 and i686 LynxOS (version 5.x).
2816 ** GDBserver is now supported on Blackfin Linux.
2818 * New native configurations
2820 ia64 HP-UX ia64-*-hpux*
2824 Analog Devices, Inc. Blackfin Processor bfin-*
2826 * Ada task switching is now supported on sparc-elf targets when
2827 debugging a program using the Ravenscar Profile. For more information,
2828 see the "Tasking Support when using the Ravenscar Profile" section
2829 in the GDB user manual.
2831 * Guile support was removed.
2833 * New features in the GNU simulator
2835 ** The --map-info flag lists all known core mappings.
2837 ** CFI flashes may be simulated via the "cfi" device.
2839 *** Changes in GDB 7.2
2841 * Shared library support for remote targets by default
2843 When GDB is configured for a generic, non-OS specific target, like
2844 for example, --target=arm-eabi or one of the many *-*-elf targets,
2845 GDB now queries remote stubs for loaded shared libraries using the
2846 `qXfer:libraries:read' packet. Previously, shared library support
2847 was always disabled for such configurations.
2851 ** Argument Dependent Lookup (ADL)
2853 In C++ ADL lookup directs function search to the namespaces of its
2854 arguments even if the namespace has not been imported.
2864 Here the compiler will search for `foo' in the namespace of 'b'
2865 and find A::foo. GDB now supports this. This construct is commonly
2866 used in the Standard Template Library for operators.
2868 ** Improved User Defined Operator Support
2870 In addition to member operators, GDB now supports lookup of operators
2871 defined in a namespace and imported with a `using' directive, operators
2872 defined in the global scope, operators imported implicitly from an
2873 anonymous namespace, and the ADL operators mentioned in the previous
2875 GDB now also supports proper overload resolution for all the previously
2876 mentioned flavors of operators.
2878 ** static const class members
2880 Printing of static const class members that are initialized in the
2881 class definition has been fixed.
2883 * Windows Thread Information Block access.
2885 On Windows targets, GDB now supports displaying the Windows Thread
2886 Information Block (TIB) structure. This structure is visible either
2887 by using the new command `info w32 thread-information-block' or, by
2888 dereferencing the new convenience variable named `$_tlb', a
2889 thread-specific pointer to the TIB. This feature is also supported
2890 when remote debugging using GDBserver.
2892 * Static tracepoints
2894 Static tracepoints are calls in the user program into a tracing
2895 library. One such library is a port of the LTTng kernel tracer to
2896 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2897 When debugging with GDBserver, GDB now supports combining the GDB
2898 tracepoint machinery with such libraries. For example: the user can
2899 use GDB to probe a static tracepoint marker (a call from the user
2900 program into the tracing library) with the new "strace" command (see
2901 "New commands" below). This creates a "static tracepoint" in the
2902 breakpoint list, that can be manipulated with the same feature set
2903 as fast and regular tracepoints. E.g., collect registers, local and
2904 global variables, collect trace state variables, and define
2905 tracepoint conditions. In addition, the user can collect extra
2906 static tracepoint marker specific data, by collecting the new
2907 $_sdata internal variable. When analyzing the trace buffer, you can
2908 inspect $_sdata like any other variable available to GDB. For more
2909 information, see the "Tracepoints" chapter in GDB user manual. New
2910 remote packets have been defined to support static tracepoints, see
2911 the "New remote packets" section below.
2913 * Better reconstruction of tracepoints after disconnected tracing
2915 GDB will attempt to download the original source form of tracepoint
2916 definitions when starting a trace run, and then will upload these
2917 upon reconnection to the target, resulting in a more accurate
2918 reconstruction of the tracepoints that are in use on the target.
2922 You can now exercise direct control over the ways that GDB can
2923 affect your program. For instance, you can disallow the setting of
2924 breakpoints, so that the program can run continuously (assuming
2925 non-stop mode). In addition, the "observer" variable is available
2926 to switch all of the different controls; in observer mode, GDB
2927 cannot affect the target's behavior at all, which is useful for
2928 tasks like diagnosing live systems in the field.
2930 * The new convenience variable $_thread holds the number of the
2933 * New remote packets
2937 Return the address of the Windows Thread Information Block of a given thread.
2941 In response to several of the tracepoint packets, the target may now
2942 also respond with a number of intermediate `qRelocInsn' request
2943 packets before the final result packet, to have GDB handle
2944 relocating an instruction to execute at a different address. This
2945 is particularly useful for stubs that support fast tracepoints. GDB
2946 reports support for this feature in the qSupported packet.
2950 List static tracepoint markers in the target program.
2954 List static tracepoint markers at a given address in the target
2957 qXfer:statictrace:read
2959 Read the static trace data collected (by a `collect $_sdata'
2960 tracepoint action). The remote stub reports support for this packet
2961 to gdb's qSupported query.
2965 Send the current settings of GDB's permission flags.
2969 Send part of the source (textual) form of a tracepoint definition,
2970 which includes location, conditional, and action list.
2972 * The source command now accepts a -s option to force searching for the
2973 script in the source search path even if the script name specifies
2976 * New features in the GDB remote stub, GDBserver
2978 - GDBserver now support tracepoints (including fast tracepoints, and
2979 static tracepoints). The feature is currently supported by the
2980 i386-linux and amd64-linux builds. See the "Tracepoints support
2981 in gdbserver" section in the manual for more information.
2983 GDBserver JIT compiles the tracepoint's conditional agent
2984 expression bytecode into native code whenever possible for low
2985 overhead dynamic tracepoints conditionals. For such tracepoints,
2986 an expression that examines program state is evaluated when the
2987 tracepoint is reached, in order to determine whether to capture
2988 trace data. If the condition is simple and false, processing the
2989 tracepoint finishes very quickly and no data is gathered.
2991 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2992 for static tracepoints support.
2994 - GDBserver now supports x86_64 Windows 64-bit debugging.
2996 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2997 it understands register description.
2999 * The --batch flag now disables pagination and queries.
3001 * X86 general purpose registers
3003 GDB now supports reading/writing byte, word and double-word x86
3004 general purpose registers directly. This means you can use, say,
3005 $ah or $ax to refer, respectively, to the byte register AH and
3006 16-bit word register AX that are actually portions of the 32-bit
3007 register EAX or 64-bit register RAX.
3009 * The `commands' command now accepts a range of breakpoints to modify.
3010 A plain `commands' following a command that creates multiple
3011 breakpoints affects all the breakpoints set by that command. This
3012 applies to breakpoints set by `rbreak', and also applies when a
3013 single `break' command creates multiple breakpoints (e.g.,
3014 breakpoints on overloaded c++ functions).
3016 * The `rbreak' command now accepts a filename specification as part of
3017 its argument, limiting the functions selected by the regex to those
3018 in the specified file.
3020 * Support for remote debugging Windows and SymbianOS shared libraries
3021 from Unix hosts has been improved. Non Windows GDB builds now can
3022 understand target reported file names that follow MS-DOS based file
3023 system semantics, such as file names that include drive letters and
3024 use the backslash character as directory separator. This makes it
3025 possible to transparently use the "set sysroot" and "set
3026 solib-search-path" on Unix hosts to point as host copies of the
3027 target's shared libraries. See the new command "set
3028 target-file-system-kind" described below, and the "Commands to
3029 specify files" section in the user manual for more information.
3033 eval template, expressions...
3034 Convert the values of one or more expressions under the control
3035 of the string template to a command line, and call it.
3037 set target-file-system-kind unix|dos-based|auto
3038 show target-file-system-kind
3039 Set or show the assumed file system kind for target reported file
3042 save breakpoints <filename>
3043 Save all current breakpoint definitions to a file suitable for use
3044 in a later debugging session. To read the saved breakpoint
3045 definitions, use the `source' command.
3047 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3050 info static-tracepoint-markers
3051 Display information about static tracepoint markers in the target.
3053 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3054 Define a static tracepoint by probing a marker at the given
3055 function, line, address, or marker ID.
3059 Enable and disable observer mode.
3061 set may-write-registers on|off
3062 set may-write-memory on|off
3063 set may-insert-breakpoints on|off
3064 set may-insert-tracepoints on|off
3065 set may-insert-fast-tracepoints on|off
3066 set may-interrupt on|off
3067 Set individual permissions for GDB effects on the target. Note that
3068 some of these settings can have undesirable or surprising
3069 consequences, particularly when changed in the middle of a session.
3070 For instance, disabling the writing of memory can prevent
3071 breakpoints from being inserted, cause single-stepping to fail, or
3072 even crash your program, if you disable after breakpoints have been
3073 inserted. However, GDB should not crash.
3075 set record memory-query on|off
3076 show record memory-query
3077 Control whether to stop the inferior if memory changes caused
3078 by an instruction cannot be recorded.
3083 The disassemble command now supports "start,+length" form of two arguments.
3087 ** GDB now provides a new directory location, called the python directory,
3088 where Python scripts written for GDB can be installed. The location
3089 of that directory is <data-directory>/python, where <data-directory>
3090 is the GDB data directory. For more details, see section `Scripting
3091 GDB using Python' in the manual.
3093 ** The GDB Python API now has access to breakpoints, symbols, symbol
3094 tables, program spaces, inferiors, threads and frame's code blocks.
3095 Additionally, GDB Parameters can now be created from the API, and
3096 manipulated via set/show in the CLI.
3098 ** New functions gdb.target_charset, gdb.target_wide_charset,
3099 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3101 ** New exception gdb.GdbError.
3103 ** Pretty-printers are now also looked up in the current program space.
3105 ** Pretty-printers can now be individually enabled and disabled.
3107 ** GDB now looks for names of Python scripts to auto-load in a
3108 special section named `.debug_gdb_scripts', in addition to looking
3109 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3111 * Tracepoint actions were unified with breakpoint commands. In particular,
3112 there are no longer differences in "info break" output for breakpoints and
3113 tracepoints and the "commands" command can be used for both tracepoints and
3114 regular breakpoints.
3118 ARM Symbian arm*-*-symbianelf*
3120 * D language support.
3121 GDB now supports debugging programs written in the D programming
3124 * GDB now supports the extended ptrace interface for PowerPC which is
3125 available since Linux kernel version 2.6.34. This automatically enables
3126 any hardware breakpoints and additional hardware watchpoints available in
3127 the processor. The old ptrace interface exposes just one hardware
3128 watchpoint and no hardware breakpoints.
3130 * GDB is now able to use the Data Value Compare (DVC) register available on
3131 embedded PowerPC processors to implement in hardware simple watchpoint
3132 conditions of the form:
3134 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3136 This works in native GDB running on Linux kernels with the extended ptrace
3137 interface mentioned above.
3139 *** Changes in GDB 7.1
3143 ** Namespace Support
3145 GDB now supports importing of namespaces in C++. This enables the
3146 user to inspect variables from imported namespaces. Support for
3147 namepace aliasing has also been added. So, if a namespace is
3148 aliased in the current scope (e.g. namepace C=A; ) the user can
3149 print variables using the alias (e.g. (gdb) print C::x).
3153 All known bugs relating to the printing of virtual base class were
3154 fixed. It is now possible to call overloaded static methods using a
3159 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3160 and reinterpret_cast<> are now handled by the C++ expression parser.
3164 Xilinx MicroBlaze microblaze-*-*
3169 Xilinx MicroBlaze microblaze
3172 * Multi-program debugging.
3174 GDB now has support for multi-program (a.k.a. multi-executable or
3175 multi-exec) debugging. This allows for debugging multiple inferiors
3176 simultaneously each running a different program under the same GDB
3177 session. See "Debugging Multiple Inferiors and Programs" in the
3178 manual for more information. This implied some user visible changes
3179 in the multi-inferior support. For example, "info inferiors" now
3180 lists inferiors that are not running yet or that have exited
3181 already. See also "New commands" and "New options" below.
3183 * New tracing features
3185 GDB's tracepoint facility now includes several new features:
3187 ** Trace state variables
3189 GDB tracepoints now include support for trace state variables, which
3190 are variables managed by the target agent during a tracing
3191 experiment. They are useful for tracepoints that trigger each
3192 other, so for instance one tracepoint can count hits in a variable,
3193 and then a second tracepoint has a condition that is true when the
3194 count reaches a particular value. Trace state variables share the
3195 $-syntax of GDB convenience variables, and can appear in both
3196 tracepoint actions and condition expressions. Use the "tvariable"
3197 command to create, and "info tvariables" to view; see "Trace State
3198 Variables" in the manual for more detail.
3202 GDB now includes an option for defining fast tracepoints, which
3203 targets may implement more efficiently, such as by installing a jump
3204 into the target agent rather than a trap instruction. The resulting
3205 speedup can be by two orders of magnitude or more, although the
3206 tradeoff is that some program locations on some target architectures
3207 might not allow fast tracepoint installation, for instance if the
3208 instruction to be replaced is shorter than the jump. To request a
3209 fast tracepoint, use the "ftrace" command, with syntax identical to
3210 the regular trace command.
3212 ** Disconnected tracing
3214 It is now possible to detach GDB from the target while it is running
3215 a trace experiment, then reconnect later to see how the experiment
3216 is going. In addition, a new variable disconnected-tracing lets you
3217 tell the target agent whether to continue running a trace if the
3218 connection is lost unexpectedly.
3222 GDB now has the ability to save the trace buffer into a file, and
3223 then use that file as a target, similarly to you can do with
3224 corefiles. You can select trace frames, print data that was
3225 collected in them, and use tstatus to display the state of the
3226 tracing run at the moment that it was saved. To create a trace
3227 file, use "tsave <filename>", and to use it, do "target tfile
3230 ** Circular trace buffer
3232 You can ask the target agent to handle the trace buffer as a
3233 circular buffer, discarding the oldest trace frames to make room for
3234 newer ones, by setting circular-trace-buffer to on. This feature may
3235 not be available for all target agents.
3240 The disassemble command, when invoked with two arguments, now requires
3241 the arguments to be comma-separated.
3244 The info variables command now displays variable definitions. Files
3245 which only declare a variable are not shown.
3248 The source command is now capable of sourcing Python scripts.
3249 This feature is dependent on the debugger being build with Python
3252 Related to this enhancement is also the introduction of a new command
3253 "set script-extension" (see below).
3255 * New commands (for set/show, see "New options" below)
3257 record save [<FILENAME>]
3258 Save a file (in core file format) containing the process record
3259 execution log for replay debugging at a later time.
3261 record restore <FILENAME>
3262 Restore the process record execution log that was saved at an
3263 earlier time, for replay debugging.
3265 add-inferior [-copies <N>] [-exec <FILENAME>]
3268 clone-inferior [-copies <N>] [ID]
3269 Make a new inferior ready to execute the same program another
3270 inferior has loaded.
3275 maint info program-spaces
3276 List the program spaces loaded into GDB.
3278 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3279 show remote interrupt-sequence
3280 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3281 as the sequence to the remote target in order to interrupt the execution.
3282 Ctrl-C is a default. Some system prefers BREAK which is high level of
3283 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3284 Magic SysRq g. It is BREAK signal and character 'g'.
3286 set remote interrupt-on-connect [on | off]
3287 show remote interrupt-on-connect
3288 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3289 remote target when gdb connects to it. This is needed when you debug
3292 set remotebreak [on | off]
3294 Deprecated. Use "set/show remote interrupt-sequence" instead.
3296 tvariable $NAME [ = EXP ]
3297 Create or modify a trace state variable.
3300 List trace state variables and their values.
3302 delete tvariable $NAME ...
3303 Delete one or more trace state variables.
3306 Evaluate the given expressions without collecting anything into the
3307 trace buffer. (Valid in tracepoint actions only.)
3309 ftrace FN / FILE:LINE / *ADDR
3310 Define a fast tracepoint at the given function, line, or address.
3312 * New expression syntax
3314 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3315 GDB now parses 0b101010 identically with 42.
3319 set follow-exec-mode new|same
3320 show follow-exec-mode
3321 Control whether GDB reuses the same inferior across an exec call or
3322 creates a new one. This is useful to be able to restart the old
3323 executable after the inferior having done an exec call.
3325 set default-collect EXPR, ...
3326 show default-collect
3327 Define a list of expressions to be collected at each tracepoint.
3328 This is a useful way to ensure essential items are not overlooked,
3329 such as registers or a critical global variable.
3331 set disconnected-tracing
3332 show disconnected-tracing
3333 If set to 1, the target is instructed to continue tracing if it
3334 loses its connection to GDB. If 0, the target is to stop tracing
3337 set circular-trace-buffer
3338 show circular-trace-buffer
3339 If set to on, the target is instructed to use a circular trace buffer
3340 and discard the oldest trace frames instead of stopping the trace due
3341 to a full trace buffer. If set to off, the trace stops when the buffer
3342 fills up. Some targets may not support this.
3344 set script-extension off|soft|strict
3345 show script-extension
3346 If set to "off", the debugger does not perform any script language
3347 recognition, and all sourced files are assumed to be GDB scripts.
3348 If set to "soft" (the default), files are sourced according to
3349 filename extension, falling back to GDB scripts if the first
3351 If set to "strict", files are sourced according to filename extension.
3353 set ada trust-PAD-over-XVS on|off
3354 show ada trust-PAD-over-XVS
3355 If off, activate a workaround against a bug in the debugging information
3356 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3357 the GCC sources for more information about the GNAT encoding and
3358 PAD types in particular). It is always safe to set this option to
3359 off, but this introduces a slight performance penalty. The default
3362 * Python API Improvements
3364 ** GDB provides the new class gdb.LazyString. This is useful in
3365 some pretty-printing cases. The new method gdb.Value.lazy_string
3366 provides a simple way to create objects of this type.
3368 ** The fields returned by gdb.Type.fields now have an
3369 `is_base_class' attribute.
3371 ** The new method gdb.Type.range returns the range of an array type.
3373 ** The new method gdb.parse_and_eval can be used to parse and
3374 evaluate an expression.
3376 * New remote packets
3379 Define a trace state variable.
3382 Get the current value of a trace state variable.
3385 Set desired tracing behavior upon disconnection.
3388 Set the trace buffer to be linear or circular.
3391 Get data about the tracepoints currently in use.
3395 Process record now works correctly with hardware watchpoints.
3397 Multiple bug fixes have been made to the mips-irix port, making it
3398 much more reliable. In particular:
3399 - Debugging threaded applications is now possible again. Previously,
3400 GDB would hang while starting the program, or while waiting for
3401 the program to stop at a breakpoint.
3402 - Attaching to a running process no longer hangs.
3403 - An error occurring while loading a core file has been fixed.
3404 - Changing the value of the PC register now works again. This fixes
3405 problems observed when using the "jump" command, or when calling
3406 a function from GDB, or even when assigning a new value to $pc.
3407 - With the "finish" and "return" commands, the return value for functions
3408 returning a small array is now correctly printed.
3409 - It is now possible to break on shared library code which gets executed
3410 during a shared library init phase (code executed while executing
3411 their .init section). Previously, the breakpoint would have no effect.
3412 - GDB is now able to backtrace through the signal handler for
3413 non-threaded programs.
3415 PIE (Position Independent Executable) programs debugging is now supported.
3416 This includes debugging execution of PIC (Position Independent Code) shared
3417 libraries although for that, it should be possible to run such libraries as an
3420 *** Changes in GDB 7.0
3422 * GDB now has an interface for JIT compilation. Applications that
3423 dynamically generate code can create symbol files in memory and register
3424 them with GDB. For users, the feature should work transparently, and
3425 for JIT developers, the interface is documented in the GDB manual in the
3426 "JIT Compilation Interface" chapter.
3428 * Tracepoints may now be conditional. The syntax is as for
3429 breakpoints; either an "if" clause appended to the "trace" command,
3430 or the "condition" command is available. GDB sends the condition to
3431 the target for evaluation using the same bytecode format as is used
3432 for tracepoint actions.
3434 * The disassemble command now supports: an optional /r modifier, print the
3435 raw instructions in hex as well as in symbolic form, and an optional /m
3436 modifier to print mixed source+assembly.
3438 * Process record and replay
3440 In a architecture environment that supports ``process record and
3441 replay'', ``process record and replay'' target can record a log of
3442 the process execution, and replay it with both forward and reverse
3445 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3446 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3447 set execution-direction {forward|reverse}, for targets that support
3450 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3451 feature is available with a native GDB running on kernel version
3454 * GDB now has support for multi-byte and wide character sets on the
3455 target. Strings whose character type is wchar_t, char16_t, or
3456 char32_t are now correctly printed. GDB supports wide- and unicode-
3457 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3458 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3459 `printf'. This feature requires iconv to work properly; if your
3460 system does not have a working iconv, GDB can use GNU libiconv. See
3461 the installation instructions for more information.
3463 * GDB now supports automatic retrieval of shared library files from
3464 remote targets. To use this feature, specify a system root that begins
3465 with the `remote:' prefix, either via the `set sysroot' command or via
3466 the `--with-sysroot' configure-time option.
3468 * "info sharedlibrary" now takes an optional regex of libraries to show,
3469 and it now reports if a shared library has no debugging information.
3471 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3472 now complete on file names.
3474 * When completing in expressions, gdb will attempt to limit
3475 completions to allowable structure or union fields, where appropriate.
3476 For instance, consider:
3478 # struct example { int f1; double f2; };
3479 # struct example variable;
3482 If the user types TAB at the end of this command line, the available
3483 completions will be "f1" and "f2".
3485 * Inlined functions are now supported. They show up in backtraces, and
3486 the "step", "next", and "finish" commands handle them automatically.
3488 * GDB now supports the token-splicing (##) and stringification (#)
3489 operators when expanding macros. It also supports variable-arity
3492 * GDB now supports inspecting extra signal information, exported by
3493 the new $_siginfo convenience variable. The feature is currently
3494 implemented on linux ARM, i386 and amd64.
3496 * GDB can now display the VFP floating point registers and NEON vector
3497 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3498 can provide these registers (requires Linux 2.6.30 or later). Remote
3499 and simulator targets may also provide them.
3501 * New remote packets
3504 Search memory for a sequence of bytes.
3507 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3508 operation over reliable transport links. Use of this packet is
3509 controlled by the `set remote noack-packet' command.
3512 Kill the process with the specified process ID. Use this in preference
3513 to `k' when multiprocess protocol extensions are supported.
3516 Obtains additional operating system information
3520 Read or write additional signal information.
3522 * Removed remote protocol undocumented extension
3524 An undocumented extension to the remote protocol's `S' stop reply
3525 packet that permited the stub to pass a process id was removed.
3526 Remote servers should use the `T' stop reply packet instead.
3528 * GDB now supports multiple function calling conventions according to the
3529 DWARF-2 DW_AT_calling_convention function attribute.
3531 * The SH target utilizes the aforementioned change to distinguish between gcc
3532 and Renesas calling convention. It also adds the new CLI commands
3533 `set/show sh calling-convention'.
3535 * GDB can now read compressed debug sections, as produced by GNU gold
3536 with the --compress-debug-sections=zlib flag.
3538 * 64-bit core files are now supported on AIX.
3540 * Thread switching is now supported on Tru64.
3542 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3543 which will be allocated using malloc later in program execution.
3545 * The qXfer:libraries:read remote procotol packet now allows passing a
3546 list of section offsets.
3548 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3549 conditions handling signals delivered during attach or thread creation
3550 have also been fixed.
3552 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3553 From the user's standpoint, all unqualified instances of True and False
3554 are treated as the standard definitions, regardless of context.
3556 * GDB now parses C++ symbol and type names more flexibly. For
3559 template<typename T> class C { };
3562 GDB will now correctly handle all of:
3564 ptype C<char const *>
3565 ptype C<char const*>
3566 ptype C<const char *>
3567 ptype C<const char*>
3569 * New features in the GDB remote stub, gdbserver
3571 - The "--wrapper" command-line argument tells gdbserver to use a
3572 wrapper program to launch programs for debugging.
3574 - On PowerPC and S/390 targets, it is now possible to use a single
3575 gdbserver executable to debug both 32-bit and 64-bit programs.
3576 (This requires gdbserver itself to be built as a 64-bit executable.)
3578 - gdbserver uses the new noack protocol mode for TCP connections to
3579 reduce communications latency, if also supported and enabled in GDB.
3581 - Support for the sparc64-linux-gnu target is now included in
3584 - The amd64-linux build of gdbserver now supports debugging both
3585 32-bit and 64-bit programs.
3587 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3588 now support hardware watchpoints, and will use them automatically
3593 GDB now has support for scripting using Python. Whether this is
3594 available is determined at configure time.
3596 New GDB commands can now be written in Python.
3598 * Ada tasking support
3600 Ada tasks can now be inspected in GDB. The following commands have
3604 Print the list of Ada tasks.
3606 Print detailed information about task number N.
3608 Print the task number of the current task.
3610 Switch the context of debugging to task number N.
3612 * Support for user-defined prefixed commands. The "define" command can
3613 add new commands to existing prefixes, e.g. "target".
3615 * Multi-inferior, multi-process debugging.
3617 GDB now has generalized support for multi-inferior debugging. See
3618 "Debugging Multiple Inferiors" in the manual for more information.
3619 Although availability still depends on target support, the command
3620 set is more uniform now. The GNU/Linux specific multi-forks support
3621 has been migrated to this new framework. This implied some user
3622 visible changes; see "New commands" and also "Removed commands"
3625 * Target descriptions can now describe the target OS ABI. See the
3626 "Target Description Format" section in the user manual for more
3629 * Target descriptions can now describe "compatible" architectures
3630 to indicate that the target can execute applications for a different
3631 architecture in addition to those for the main target architecture.
3632 See the "Target Description Format" section in the user manual for
3635 * Multi-architecture debugging.
3637 GDB now includes general supports for debugging applications on
3638 hybrid systems that use more than one single processor architecture
3639 at the same time. Each such hybrid architecture still requires
3640 specific support to be added. The only hybrid architecture supported
3641 in this version of GDB is the Cell Broadband Engine.
3643 * GDB now supports integrated debugging of Cell/B.E. applications that
3644 use both the PPU and SPU architectures. To enable support for hybrid
3645 Cell/B.E. debugging, you need to configure GDB to support both the
3646 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3647 --enable-targets configure option.
3649 * Non-stop mode debugging.
3651 For some targets, GDB now supports an optional mode of operation in
3652 which you can examine stopped threads while other threads continue
3653 to execute freely. This is referred to as non-stop mode, with the
3654 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3655 section in the user manual for more information.
3657 To be able to support remote non-stop debugging, a remote stub needs
3658 to implement the non-stop mode remote protocol extensions, as
3659 described in the "Remote Non-Stop" section of the user manual. The
3660 GDB remote stub, gdbserver, has been adjusted to support these
3661 extensions on linux targets.
3663 * New commands (for set/show, see "New options" below)
3665 catch syscall [NAME(S) | NUMBER(S)]
3666 Catch system calls. Arguments, which should be names of system
3667 calls or their numbers, mean catch only those syscalls. Without
3668 arguments, every syscall will be caught. When the inferior issues
3669 any of the specified syscalls, GDB will stop and announce the system
3670 call, both when it is called and when its call returns. This
3671 feature is currently available with a native GDB running on the
3672 Linux Kernel, under the following architectures: x86, x86_64,
3673 PowerPC and PowerPC64.
3675 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3677 Search memory for a sequence of bytes.
3679 maint set python print-stack
3680 maint show python print-stack
3681 Show a stack trace when an error is encountered in a Python script.
3684 Invoke CODE by passing it to the Python interpreter.
3689 These allow macros to be defined, undefined, and listed
3693 Show operating system information about processes.
3696 List the inferiors currently under GDB's control.
3699 Switch focus to inferior number NUM.
3702 Detach from inferior number NUM.
3705 Kill inferior number NUM.
3709 set spu stop-on-load
3710 show spu stop-on-load
3711 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3713 set spu auto-flush-cache
3714 show spu auto-flush-cache
3715 Control whether to automatically flush the software-managed cache
3716 during Cell/B.E. debugging.
3718 set sh calling-convention
3719 show sh calling-convention
3720 Control the calling convention used when calling SH target functions.
3723 show debug timestamp
3724 Control display of timestamps with GDB debugging output.
3726 set disassemble-next-line
3727 show disassemble-next-line
3728 Control display of disassembled source lines or instructions when
3731 set remote noack-packet
3732 show remote noack-packet
3733 Set/show the use of remote protocol QStartNoAckMode packet. See above
3734 under "New remote packets."
3736 set remote query-attached-packet
3737 show remote query-attached-packet
3738 Control use of remote protocol `qAttached' (query-attached) packet.
3740 set remote read-siginfo-object
3741 show remote read-siginfo-object
3742 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3745 set remote write-siginfo-object
3746 show remote write-siginfo-object
3747 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3750 set remote reverse-continue
3751 show remote reverse-continue
3752 Control use of remote protocol 'bc' (reverse-continue) packet.
3754 set remote reverse-step
3755 show remote reverse-step
3756 Control use of remote protocol 'bs' (reverse-step) packet.
3758 set displaced-stepping
3759 show displaced-stepping
3760 Control displaced stepping mode. Displaced stepping is a way to
3761 single-step over breakpoints without removing them from the debuggee.
3762 Also known as "out-of-line single-stepping".
3765 show debug displaced
3766 Control display of debugging info for displaced stepping.
3768 maint set internal-error
3769 maint show internal-error
3770 Control what GDB does when an internal error is detected.
3772 maint set internal-warning
3773 maint show internal-warning
3774 Control what GDB does when an internal warning is detected.
3779 Use a wrapper program to launch programs for debugging.
3781 set multiple-symbols (all|ask|cancel)
3782 show multiple-symbols
3783 The value of this variable can be changed to adjust the debugger behavior
3784 when an expression or a breakpoint location contains an ambiguous symbol
3785 name (an overloaded function name, for instance).
3787 set breakpoint always-inserted
3788 show breakpoint always-inserted
3789 Keep breakpoints always inserted in the target, as opposed to inserting
3790 them when resuming the target, and removing them when the target stops.
3791 This option can improve debugger performance on slow remote targets.
3793 set arm fallback-mode (arm|thumb|auto)
3794 show arm fallback-mode
3795 set arm force-mode (arm|thumb|auto)
3797 These commands control how ARM GDB determines whether instructions
3798 are ARM or Thumb. The default for both settings is auto, which uses
3799 the current CPSR value for instructions without symbols; previous
3800 versions of GDB behaved as if "set arm fallback-mode arm".
3802 set disable-randomization
3803 show disable-randomization
3804 Standalone programs run with the virtual address space randomization enabled
3805 by default on some platforms. This option keeps the addresses stable across
3806 multiple debugging sessions.
3810 Control whether other threads are stopped or not when some thread hits
3815 Requests that asynchronous execution is enabled in the target, if available.
3816 In this case, it's possible to resume target in the background, and interact
3817 with GDB while the target is running. "show target-async" displays the
3818 current state of asynchronous execution of the target.
3820 set target-wide-charset
3821 show target-wide-charset
3822 The target-wide-charset is the name of the character set that GDB
3823 uses when printing characters whose type is wchar_t.
3825 set tcp auto-retry (on|off)
3827 set tcp connect-timeout
3828 show tcp connect-timeout
3829 These commands allow GDB to retry failed TCP connections to a remote stub
3830 with a specified timeout period; this is useful if the stub is launched
3831 in parallel with GDB but may not be ready to accept connections immediately.
3833 set libthread-db-search-path
3834 show libthread-db-search-path
3835 Control list of directories which GDB will search for appropriate
3838 set schedule-multiple (on|off)
3839 show schedule-multiple
3840 Allow GDB to resume all threads of all processes or only threads of
3841 the current process.
3845 Use more aggressive caching for accesses to the stack. This improves
3846 performance of remote debugging (particularly backtraces) without
3847 affecting correctness.
3849 set interactive-mode (on|off|auto)
3850 show interactive-mode
3851 Control whether GDB runs in interactive mode (on) or not (off).
3852 When in interactive mode, GDB waits for the user to answer all
3853 queries. Otherwise, GDB does not wait and assumes the default
3854 answer. When set to auto (the default), GDB determines which
3855 mode to use based on the stdin settings.
3860 For program forks, this is replaced by the new more generic `info
3861 inferiors' command. To list checkpoints, you can still use the
3862 `info checkpoints' command, which was an alias for the `info forks'
3866 Replaced by the new `inferior' command. To switch between
3867 checkpoints, you can still use the `restart' command, which was an
3868 alias for the `fork' command.
3871 This is removed, since some targets don't have a notion of
3872 processes. To switch between processes, you can still use the
3873 `inferior' command using GDB's own inferior number.
3876 For program forks, this is replaced by the new more generic `kill
3877 inferior' command. To delete a checkpoint, you can still use the
3878 `delete checkpoint' command, which was an alias for the `delete
3882 For program forks, this is replaced by the new more generic `detach
3883 inferior' command. To detach a checkpoint, you can still use the
3884 `detach checkpoint' command, which was an alias for the `detach
3887 * New native configurations
3889 x86/x86_64 Darwin i[34567]86-*-darwin*
3891 x86_64 MinGW x86_64-*-mingw*
3895 Lattice Mico32 lm32-*
3896 x86 DICOS i[34567]86-*-dicos*
3897 x86_64 DICOS x86_64-*-dicos*
3900 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3901 (mingw32ce) debugging.
3907 These commands were actually not implemented on any target.
3909 *** Changes in GDB 6.8
3911 * New native configurations
3913 NetBSD/hppa hppa*-*netbsd*
3914 Xtensa GNU/Linux xtensa*-*-linux*
3918 NetBSD/hppa hppa*-*-netbsd*
3919 Xtensa GNU/Lunux xtensa*-*-linux*
3921 * Change in command line behavior -- corefiles vs. process ids.
3923 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3924 attaching to process NUMBER fails, GDB no longer attempts to open a
3925 core file named NUMBER. Attaching to a program using the -c option
3926 is no longer supported. Instead, use the '-p' or '--pid' options.
3928 * GDB can now be built as a native debugger for debugging Windows x86
3929 (mingw32) Portable Executable (PE) programs.
3931 * Pending breakpoints no longer change their number when their address
3934 * GDB now supports breakpoints with multiple locations,
3935 including breakpoints on C++ constructors, inside C++ templates,
3936 and in inlined functions.
3938 * GDB's ability to debug optimized code has been improved. GDB more
3939 accurately identifies function bodies and lexical blocks that occupy
3940 more than one contiguous range of addresses.
3942 * Target descriptions can now describe registers for PowerPC.
3944 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3945 registers on PowerPC targets.
3947 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3948 targets even when the libthread_db library is not available.
3950 * The GDB remote stub, gdbserver, now supports the new file transfer
3951 commands (remote put, remote get, and remote delete).
3953 * The GDB remote stub, gdbserver, now supports run and attach in
3954 extended-remote mode.
3956 * hppa*64*-*-hpux11* target broken
3957 The debugger is unable to start a program and fails with the following
3958 error: "Error trying to get information about dynamic linker".
3959 The gdb-6.7 release is also affected.
3961 * GDB now supports the --enable-targets= configure option to allow
3962 building a single GDB executable that supports multiple remote
3963 target architectures.
3965 * GDB now supports debugging C and C++ programs which use the
3966 Decimal Floating Point extension. In addition, the PowerPC target
3967 now has a set of pseudo-registers to inspect decimal float values
3968 stored in two consecutive float registers.
3970 * The -break-insert MI command can optionally create pending
3973 * Improved support for debugging Ada
3974 Many improvements to the Ada language support have been made. These
3976 - Better support for Ada2005 interface types
3977 - Improved handling of arrays and slices in general
3978 - Better support for Taft-amendment types
3979 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3981 - Improved command completion in Ada
3984 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3989 set print frame-arguments (all|scalars|none)
3990 show print frame-arguments
3991 The value of this variable can be changed to control which argument
3992 values should be printed by the debugger when displaying a frame.
3997 Transfer files to and from a remote target, and delete remote files.
4004 Transfer files to and from a remote target, and delete remote files.
4006 * New remote packets
4013 Open, close, read, write, and delete files on the remote system.
4016 Attach to an existing process on the remote system, in extended-remote
4020 Run a new process on the remote system, in extended-remote mode.
4022 *** Changes in GDB 6.7
4024 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4025 bfd, libiberty and opcodes, as revealed by static analysis donated by
4026 Coverity, Inc. (http://scan.coverity.com).
4028 * When looking up multiply-defined global symbols, GDB will now prefer the
4029 symbol definition in the current shared library if it was built using the
4030 -Bsymbolic linker option.
4032 * When the Text User Interface (TUI) is not configured, GDB will now
4033 recognize the -tui command-line option and print a message that the TUI
4036 * The GDB remote stub, gdbserver, now has lower overhead for high
4037 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4039 * GDB for MIPS targets now autodetects whether a remote target provides
4040 32-bit or 64-bit register values.
4042 * Support for C++ member pointers has been improved.
4044 * GDB now understands XML target descriptions, which specify the
4045 target's overall architecture. GDB can read a description from
4046 a local file or over the remote serial protocol.
4048 * Vectors of single-byte data use a new integer type which is not
4049 automatically displayed as character or string data.
4051 * The /s format now works with the print command. It displays
4052 arrays of single-byte integers and pointers to single-byte integers
4055 * Target descriptions can now describe target-specific registers,
4056 for architectures which have implemented the support (currently
4057 only ARM, M68K, and MIPS).
4059 * GDB and the GDB remote stub, gdbserver, now support the XScale
4062 * The GDB remote stub, gdbserver, has been updated to support
4063 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4064 has been rewritten to use the standard GDB remote protocol.
4066 * GDB can now step into C++ functions which are called through thunks.
4068 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4070 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4071 layout. It also supports a TextSeg= and DataSeg= response when only
4072 segment base addresses (rather than offsets) are available.
4074 * The /i format now outputs any trailing branch delay slot instructions
4075 immediately following the last instruction within the count specified.
4077 * The GDB remote protocol "T" stop reply packet now supports a
4078 "library" response. Combined with the new "qXfer:libraries:read"
4079 packet, this response allows GDB to debug shared libraries on targets
4080 where the operating system manages the list of loaded libraries (e.g.
4081 Windows and SymbianOS).
4083 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4084 (DLLs) on Windows and Windows CE targets.
4086 * GDB now supports a faster verification that a .debug file matches its binary
4087 according to its build-id signature, if the signature is present.
4093 Enable or disable hardware flow control (RTS/CTS) on the serial port
4094 when debugging using remote targets.
4096 set mem inaccessible-by-default
4097 show mem inaccessible-by-default
4098 If the target supplies a memory map, for instance via the remote
4099 protocol's "qXfer:memory-map:read" packet, setting this variable
4100 prevents GDB from accessing memory outside the memory map. This
4101 is useful for targets with memory mapped registers or which react
4102 badly to accesses of unmapped address space.
4104 set breakpoint auto-hw
4105 show breakpoint auto-hw
4106 If the target supplies a memory map, for instance via the remote
4107 protocol's "qXfer:memory-map:read" packet, setting this variable
4108 lets GDB use hardware breakpoints automatically for memory regions
4109 where it can not use software breakpoints. This covers both the
4110 "break" command and internal breakpoints used for other commands
4111 including "next" and "finish".
4114 catch exception unhandled
4115 Stop the program execution when Ada exceptions are raised.
4118 Stop the program execution when an Ada assertion failed.
4122 Set an alternate system root for target files. This is a more
4123 general version of "set solib-absolute-prefix", which is now
4124 an alias to "set sysroot".
4127 Provide extended SPU facility status information. This set of
4128 commands is available only when debugging the Cell/B.E. SPU
4131 * New native configurations
4133 OpenBSD/sh sh*-*openbsd*
4136 unset tdesc filename
4138 Use the specified local file as an XML target description, and do
4139 not query the target for its built-in description.
4143 OpenBSD/sh sh*-*-openbsd*
4144 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4145 Toshiba Media Processor mep-elf
4147 * New remote packets
4150 Ignore the specified signals; pass them directly to the debugged program
4151 without stopping other threads or reporting them to GDB.
4153 qXfer:features:read:
4154 Read an XML target description from the target, which describes its
4159 Read or write contents of an spufs file on the target system. These
4160 packets are available only on the Cell/B.E. SPU architecture.
4162 qXfer:libraries:read:
4163 Report the loaded shared libraries. Combined with new "T" packet
4164 response, this packet allows GDB to debug shared libraries on
4165 targets where the operating system manages the list of loaded
4166 libraries (e.g. Windows and SymbianOS).
4170 Support for these obsolete configurations has been removed.
4178 i[34567]86-*-lynxos*
4179 i[34567]86-*-netware*
4180 i[34567]86-*-sco3.2v5*
4181 i[34567]86-*-sco3.2v4*
4183 i[34567]86-*-sysv4.2*
4186 i[34567]86-*-unixware2*
4187 i[34567]86-*-unixware*
4196 * Other removed features
4203 Various m68k-only ROM monitors.
4210 Various Renesas ROM monitors and debugging interfaces for SH and
4215 Support for a Macraigor serial interface to on-chip debugging.
4216 GDB does not directly support the newer parallel or USB
4221 A debug information format. The predecessor to DWARF 2 and
4222 DWARF 3, which are still supported.
4224 Support for the HP aCC compiler on HP-UX/PA-RISC
4226 SOM-encapsulated symbolic debugging information, automatic
4227 invocation of pxdb, and the aCC custom C++ ABI. This does not
4228 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4229 with aCC can still be debugged on an assembly level.
4231 MIPS ".pdr" sections
4233 A MIPS-specific format used to describe stack frame layout
4234 in debugging information.
4238 GDB could work with an older version of Guile to debug
4239 the interpreter and Scheme programs running in it.
4241 set mips stack-arg-size
4242 set mips saved-gpreg-size
4244 Use "set mips abi" to control parameter passing for MIPS.
4246 *** Changes in GDB 6.6
4251 Cell Broadband Engine SPU spu-elf
4253 * GDB can now be configured as a cross-debugger targeting native Windows
4254 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4255 running on a Windows system over TCP/IP to debug Windows programs.
4257 * The GDB remote stub, gdbserver, has been updated to support Windows and
4258 Cygwin debugging. Both single-threaded and multi-threaded programs are
4261 * The "set trust-readonly-sections" command works again. This command was
4262 broken in GDB 6.3, 6.4, and 6.5.
4264 * The "load" command now supports writing to flash memory, if the remote
4265 stub provides the required support.
4267 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4268 longer requires symbolic debug information (e.g. DWARF-2).
4273 unset substitute-path
4274 show substitute-path
4275 Manage a list of substitution rules that GDB uses to rewrite the name
4276 of the directories where the sources are located. This can be useful
4277 for instance when the sources were moved to a different location
4278 between compilation and debugging.
4282 Print each CLI command as it is executed. Each command is prefixed with
4283 a number of `+' symbols representing the nesting depth.
4284 The source command now has a `-v' option to enable the same feature.
4288 The ARM Demon monitor support (RDP protocol, "target rdp").
4290 Kernel Object Display, an embedded debugging feature which only worked with
4291 an obsolete version of Cisco IOS.
4293 The 'set download-write-size' and 'show download-write-size' commands.
4295 * New remote packets
4298 Tell a stub about GDB client features, and request remote target features.
4299 The first feature implemented is PacketSize, which allows the target to
4300 specify the size of packets it can handle - to minimize the number of
4301 packets required and improve performance when connected to a remote
4305 Fetch an OS auxilliary vector from the remote stub. This packet is a
4306 more efficient replacement for qPart:auxv:read.
4308 qXfer:memory-map:read:
4309 Fetch a memory map from the remote stub, including information about
4310 RAM, ROM, and flash memory devices.
4315 Erase and program a flash memory device.
4317 * Removed remote packets
4320 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4321 used it, and only gdbserver implemented it.
4323 *** Changes in GDB 6.5
4327 Renesas M32C/M16C m32c-elf
4329 Morpho Technologies ms1 ms1-elf
4333 init-if-undefined Initialize a convenience variable, but
4334 only if it doesn't already have a value.
4336 The following commands are presently only implemented for native GNU/Linux:
4338 checkpoint Save a snapshot of the program state.
4340 restart <n> Return the program state to a
4341 previously saved state.
4343 info checkpoints List currently saved checkpoints.
4345 delete-checkpoint <n> Delete a previously saved checkpoint.
4347 set|show detach-on-fork Tell gdb whether to detach from a newly
4348 forked process, or to keep debugging it.
4350 info forks List forks of the user program that
4351 are available to be debugged.
4353 fork <n> Switch to debugging one of several
4354 forks of the user program that are
4355 available to be debugged.
4357 delete-fork <n> Delete a fork from the list of forks
4358 that are available to be debugged (and
4359 kill the forked process).
4361 detach-fork <n> Delete a fork from the list of forks
4362 that are available to be debugged (and
4363 allow the process to continue).
4367 Morpho Technologies ms2 ms1-elf
4369 * Improved Windows host support
4371 GDB now builds as a cross debugger hosted on i686-mingw32, including
4372 native console support, and remote communications using either
4373 network sockets or serial ports.
4375 * Improved Modula-2 language support
4377 GDB can now print most types in the Modula-2 syntax. This includes:
4378 basic types, set types, record types, enumerated types, range types,
4379 pointer types and ARRAY types. Procedure var parameters are correctly
4380 printed and hexadecimal addresses and character constants are also
4381 written in the Modula-2 syntax. Best results can be obtained by using
4382 GNU Modula-2 together with the -gdwarf-2 command line option.
4386 The ARM rdi-share module.
4388 The Netware NLM debug server.
4390 *** Changes in GDB 6.4
4392 * New native configurations
4394 OpenBSD/arm arm*-*-openbsd*
4395 OpenBSD/mips64 mips64-*-openbsd*
4399 Morpho Technologies ms1 ms1-elf
4401 * New command line options
4403 --batch-silent As for --batch, but totally silent.
4404 --return-child-result The debugger will exist with the same value
4405 the child (debugged) program exited with.
4406 --eval-command COMMAND, -ex COMMAND
4407 Execute a single GDB CLI command. This may be
4408 specified multiple times and in conjunction
4409 with the --command (-x) option.
4411 * Deprecated commands removed
4413 The following commands, that were deprecated in 2000, have been
4417 set|show arm disassembly-flavor set|show arm disassembler
4418 othernames set arm disassembler
4419 set|show remotedebug set|show debug remote
4420 set|show archdebug set|show debug arch
4421 set|show eventdebug set|show debug event
4424 * New BSD user-level threads support
4426 It is now possible to debug programs using the user-level threads
4427 library on OpenBSD and FreeBSD. Currently supported (target)
4430 FreeBSD/amd64 x86_64-*-freebsd*
4431 FreeBSD/i386 i386-*-freebsd*
4432 OpenBSD/i386 i386-*-openbsd*
4434 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4435 are not yet supported.
4437 * New support for Matsushita MN10300 w/sim added
4438 (Work in progress). mn10300-elf.
4440 * REMOVED configurations and files
4442 VxWorks and the XDR protocol *-*-vxworks
4443 Motorola MCORE mcore-*-*
4444 National Semiconductor NS32000 ns32k-*-*
4446 * New "set print array-indexes" command
4448 After turning this setting "on", GDB prints the index of each element
4449 when displaying arrays. The default is "off" to preserve the previous
4452 * VAX floating point support
4454 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4456 * User-defined command support
4458 In addition to using $arg0..$arg9 for argument passing, it is now possible
4459 to use $argc to determine now many arguments have been passed. See the
4460 section on user-defined commands in the user manual for more information.
4462 *** Changes in GDB 6.3:
4464 * New command line option
4466 GDB now accepts -l followed by a number to set the timeout for remote
4469 * GDB works with GCC -feliminate-dwarf2-dups
4471 GDB now supports a more compact representation of DWARF-2 debug
4472 information using DW_FORM_ref_addr references. These are produced
4473 by GCC with the option -feliminate-dwarf2-dups and also by some
4474 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4475 to use -feliminate-dwarf2-dups.
4477 * Internationalization
4479 When supported by the host system, GDB will be built with
4480 internationalization (libintl). The task of marking up the sources is
4481 continued, we're looking forward to our first translation.
4485 Initial support for debugging programs compiled with the GNAT
4486 implementation of the Ada programming language has been integrated
4487 into GDB. In this release, support is limited to expression evaluation.
4489 * New native configurations
4491 GNU/Linux/m32r m32r-*-linux-gnu
4495 GDB's remote protocol now includes support for the 'p' packet. This
4496 packet is used to fetch individual registers from a remote inferior.
4498 * END-OF-LIFE registers[] compatibility module
4500 GDB's internal register infrastructure has been completely rewritten.
4501 The new infrastructure making possible the implementation of key new
4502 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4505 GDB 6.3 will be the last release to include the the registers[]
4506 compatibility module that allowed out-of-date configurations to
4507 continue to work. This change directly impacts the following
4517 powerpc bdm protocol
4519 Unless there is activity to revive these configurations, they will be
4520 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4522 * OBSOLETE configurations and files
4524 Configurations that have been declared obsolete in this release have
4525 been commented out. Unless there is activity to revive these
4526 configurations, the next release of GDB will have their sources
4527 permanently REMOVED.
4536 *** Changes in GDB 6.2.1:
4538 * MIPS `break main; run' gave an heuristic-fence-post warning
4540 When attempting to run even a simple program, a warning about
4541 heuristic-fence-post being hit would be reported. This problem has
4544 * MIPS IRIX 'long double' crashed GDB
4546 When examining a long double variable, GDB would get a segmentation
4547 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4548 IRIX long double values).
4552 A bug in the VAX stack code was causing problems with the "next"
4553 command. This problem has been fixed.
4555 *** Changes in GDB 6.2:
4557 * Fix for ``many threads''
4559 On GNU/Linux systems that use the NPTL threads library, a program
4560 rapidly creating and deleting threads would confuse GDB leading to the
4563 ptrace: No such process.
4564 thread_db_get_info: cannot get thread info: generic error
4566 This problem has been fixed.
4568 * "-async" and "-noasync" options removed.
4570 Support for the broken "-noasync" option has been removed (it caused
4573 * New ``start'' command.
4575 This command runs the program until the begining of the main procedure.
4577 * New BSD Kernel Data Access Library (libkvm) interface
4579 Using ``target kvm'' it is now possible to debug kernel core dumps and
4580 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4581 platforms. Currently supported (native-only) configurations are:
4583 FreeBSD/amd64 x86_64-*-freebsd*
4584 FreeBSD/i386 i?86-*-freebsd*
4585 NetBSD/i386 i?86-*-netbsd*
4586 NetBSD/m68k m68*-*-netbsd*
4587 NetBSD/sparc sparc-*-netbsd*
4588 OpenBSD/amd64 x86_64-*-openbsd*
4589 OpenBSD/i386 i?86-*-openbsd*
4590 OpenBSD/m68k m68*-openbsd*
4591 OpenBSD/sparc sparc-*-openbsd*
4593 * Signal trampoline code overhauled
4595 Many generic problems with GDB's signal handling code have been fixed.
4596 These include: backtraces through non-contiguous stacks; recognition
4597 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4598 call; backtrace through a signal trampoline; step into and out of
4599 signal handlers; and single-stepping in the signal trampoline.
4601 Please note that kernel bugs are a limiting factor here. These
4602 features have been shown to work on an s390 GNU/Linux system that
4603 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4605 * Cygwin support for DWARF 2 added.
4607 * New native configurations
4609 GNU/Linux/hppa hppa*-*-linux*
4610 OpenBSD/hppa hppa*-*-openbsd*
4611 OpenBSD/m68k m68*-*-openbsd*
4612 OpenBSD/m88k m88*-*-openbsd*
4613 OpenBSD/powerpc powerpc-*-openbsd*
4614 NetBSD/vax vax-*-netbsd*
4615 OpenBSD/vax vax-*-openbsd*
4617 * END-OF-LIFE frame compatibility module
4619 GDB's internal frame infrastructure has been completely rewritten.
4620 The new infrastructure making it possible to support key new features
4621 including DWARF 2 Call Frame Information. To aid in the task of
4622 migrating old configurations to this new infrastructure, a
4623 compatibility module, that allowed old configurations to continue to
4624 work, was also included.
4626 GDB 6.2 will be the last release to include this frame compatibility
4627 module. This change directly impacts the following configurations:
4637 Unless there is activity to revive these configurations, they will be
4638 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4640 * REMOVED configurations and files
4642 Sun 3, running SunOS 3 m68*-*-sunos3*
4643 Sun 3, running SunOS 4 m68*-*-sunos4*
4644 Sun 2, running SunOS 3 m68000-*-sunos3*
4645 Sun 2, running SunOS 4 m68000-*-sunos4*
4646 Motorola 680x0 running LynxOS m68*-*-lynxos*
4647 AT&T 3b1/Unix pc m68*-att-*
4648 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4649 decstation mips-dec-* mips-little-*
4650 riscos mips-*-riscos* mips-*-sysv*
4651 sonymips mips-sony-*
4652 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4654 *** Changes in GDB 6.1.1:
4656 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4658 The TUI (Text-mode User Interface) is now built as part of a default
4659 GDB configuration. It is enabled by either selecting the TUI with the
4660 command line option "-i=tui" or by running the separate "gdbtui"
4661 program. For more information on the TUI, see the manual "Debugging
4664 * Pending breakpoint support (also included in GDB 6.1)
4666 Support has been added to allow you to specify breakpoints in shared
4667 libraries that have not yet been loaded. If a breakpoint location
4668 cannot be found, and the "breakpoint pending" option is set to auto,
4669 GDB queries you if you wish to make the breakpoint pending on a future
4670 shared-library load. If and when GDB resolves the breakpoint symbol,
4671 the pending breakpoint is removed as one or more regular breakpoints
4674 Pending breakpoints are very useful for GCJ Java debugging.
4676 * Fixed ISO-C build problems
4678 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4679 non ISO-C code that stopped them being built using a more strict ISO-C
4680 compiler (e.g., IBM's C compiler).
4682 * Fixed build problem on IRIX 5
4684 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4685 wasn't able to compile compile on an IRIX 5 system.
4687 * Added execute permission to gdb/gdbserver/configure
4689 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4690 permission. This bug would cause configure to fail on a number of
4691 systems (Solaris, IRIX). Ref: server/519.
4693 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4695 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4696 has been updated to use constant array sizes.
4698 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4700 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4701 its generated DWARF Call Frame Info. This encoding was causing GDB to
4702 panic, that panic has been fixed. Ref: gdb/1628.
4704 * Fixed a problem when examining parameters in shared library code.
4706 When examining parameters in optimized shared library code generated
4707 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4708 not available''. GDB now correctly displays the variable's value.
4710 *** Changes in GDB 6.1:
4712 * Removed --with-mmalloc
4714 Support for the mmalloc memory manager has been removed, as it
4715 conflicted with the internal gdb byte cache.
4717 * Changes in AMD64 configurations
4719 The AMD64 target now includes the %cs and %ss registers. As a result
4720 the AMD64 remote protocol has changed; this affects the floating-point
4721 and SSE registers. If you rely on those registers for your debugging,
4722 you should upgrade gdbserver on the remote side.
4724 * Revised SPARC target
4726 The SPARC target has been completely revised, incorporating the
4727 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4728 support for LynxOS and SunOS 4 has been dropped. Calling functions
4729 from within GDB on operating systems with a non-executable stack
4730 (Solaris, OpenBSD) now works.
4734 GDB has a new C++ demangler which does a better job on the mangled
4735 names generated by current versions of g++. It also runs faster, so
4736 with this and other changes gdb should now start faster on large C++
4739 * DWARF 2 Location Expressions
4741 GDB support for location expressions has been extended to support function
4742 arguments and frame bases. Older versions of GDB could crash when they
4745 * C++ nested types and namespaces
4747 GDB's support for nested types and namespaces in C++ has been
4748 improved, especially if you use the DWARF 2 debugging format. (This
4749 is the default for recent versions of GCC on most platforms.)
4750 Specifically, if you have a class "Inner" defined within a class or
4751 namespace "Outer", then GDB realizes that the class's name is
4752 "Outer::Inner", not simply "Inner". This should greatly reduce the
4753 frequency of complaints about not finding RTTI symbols. In addition,
4754 if you are stopped at inside of a function defined within a namespace,
4755 GDB modifies its name lookup accordingly.
4757 * New native configurations
4759 NetBSD/amd64 x86_64-*-netbsd*
4760 OpenBSD/amd64 x86_64-*-openbsd*
4761 OpenBSD/alpha alpha*-*-openbsd*
4762 OpenBSD/sparc sparc-*-openbsd*
4763 OpenBSD/sparc64 sparc64-*-openbsd*
4765 * New debugging protocols
4767 M32R with SDI protocol m32r-*-elf*
4769 * "set prompt-escape-char" command deleted.
4771 The command "set prompt-escape-char" has been deleted. This command,
4772 and its very obscure effet on GDB's prompt, was never documented,
4773 tested, nor mentioned in the NEWS file.
4775 * OBSOLETE configurations and files
4777 Configurations that have been declared obsolete in this release have
4778 been commented out. Unless there is activity to revive these
4779 configurations, the next release of GDB will have their sources
4780 permanently REMOVED.
4782 Sun 3, running SunOS 3 m68*-*-sunos3*
4783 Sun 3, running SunOS 4 m68*-*-sunos4*
4784 Sun 2, running SunOS 3 m68000-*-sunos3*
4785 Sun 2, running SunOS 4 m68000-*-sunos4*
4786 Motorola 680x0 running LynxOS m68*-*-lynxos*
4787 AT&T 3b1/Unix pc m68*-att-*
4788 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4789 decstation mips-dec-* mips-little-*
4790 riscos mips-*-riscos* mips-*-sysv*
4791 sonymips mips-sony-*
4792 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4794 * REMOVED configurations and files
4796 SGI Irix-4.x mips-sgi-irix4 or iris4
4797 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4798 Z8000 simulator z8k-zilog-none or z8ksim
4799 Matsushita MN10200 w/simulator mn10200-*-*
4800 H8/500 simulator h8500-hitachi-hms or h8500hms
4801 HP/PA running BSD hppa*-*-bsd*
4802 HP/PA running OSF/1 hppa*-*-osf*
4803 HP/PA Pro target hppa*-*-pro*
4804 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4805 386BSD i[3456]86-*-bsd*
4806 Sequent family i[3456]86-sequent-sysv4*
4807 i[3456]86-sequent-sysv*
4808 i[3456]86-sequent-bsd*
4809 SPARC running LynxOS sparc-*-lynxos*
4810 SPARC running SunOS 4 sparc-*-sunos4*
4811 Tsqware Sparclet sparclet-*-*
4812 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4814 *** Changes in GDB 6.0:
4818 Support for debugging the Objective-C programming language has been
4819 integrated into GDB.
4821 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4823 DWARF 2's Call Frame Information makes available compiler generated
4824 information that more exactly describes the program's run-time stack.
4825 By using this information, GDB is able to provide more robust stack
4828 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4829 have been updated to use a new backtrace mechanism which includes
4830 DWARF 2 CFI support.
4834 GDB's remote protocol has been extended to include support for hosted
4835 file I/O (where the remote target uses GDB's file system). See GDB's
4836 remote protocol documentation for details.
4838 * All targets using the new architecture framework.
4840 All of GDB's targets have been updated to use the new internal
4841 architecture framework. The way is now open for future GDB releases
4842 to include cross-architecture native debugging support (i386 on amd64,
4845 * GNU/Linux's Thread Local Storage (TLS)
4847 GDB now includes support for for the GNU/Linux implementation of
4848 per-thread variables.
4850 * GNU/Linux's Native POSIX Thread Library (NPTL)
4852 GDB's thread code has been updated to work with either the new
4853 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4855 * Separate debug info.
4857 GDB, in conjunction with BINUTILS, now supports a mechanism for
4858 automatically loading debug information from a separate file. Instead
4859 of shipping full debug and non-debug versions of system libraries,
4860 system integrators can now instead ship just the stripped libraries
4861 and optional debug files.
4863 * DWARF 2 Location Expressions
4865 DWARF 2 Location Expressions allow the compiler to more completely
4866 describe the location of variables (even in optimized code) to the
4869 GDB now includes preliminary support for location expressions (support
4870 for DW_OP_piece is still missing).
4874 A number of long standing bugs that caused GDB to die while starting a
4875 Java application have been fixed. GDB's Java support is now
4876 considered "useable".
4878 * GNU/Linux support for fork, vfork, and exec.
4880 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4881 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4884 * GDB supports logging output to a file
4886 There are two new commands, "set logging" and "show logging", which can be
4887 used to capture GDB's output to a file.
4889 * The meaning of "detach" has changed for gdbserver
4891 The "detach" command will now resume the application, as documented. To
4892 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4895 * d10v, m68hc11 `regs' command deprecated
4897 The `info registers' command has been updated so that it displays the
4898 registers using a format identical to the old `regs' command.
4902 A new command, "maint set profile on/off", has been added. This command can
4903 be used to enable or disable profiling while running GDB, to profile a
4904 session or a set of commands. In addition there is a new configure switch,
4905 "--enable-profiling", which will cause GDB to be compiled with profiling
4906 data, for more informative profiling results.
4908 * Default MI syntax changed to "mi2".
4910 The default MI (machine interface) syntax, enabled by the command line
4911 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4912 "mi1", can be enabled by specifying the option "-i=mi1".
4914 Support for the original "mi0" syntax (included in GDB 5.0) has been
4917 Fix for gdb/192: removed extraneous space when displaying frame level.
4918 Fix for gdb/672: update changelist is now output in mi list format.
4919 Fix for gdb/702: a -var-assign that updates the value now shows up
4920 in a subsequent -var-update.
4922 * New native configurations.
4924 FreeBSD/amd64 x86_64-*-freebsd*
4926 * Multi-arched targets.
4928 HP/PA HPUX11 hppa*-*-hpux*
4929 Renesas M32R/D w/simulator m32r-*-elf*
4931 * OBSOLETE configurations and files
4933 Configurations that have been declared obsolete in this release have
4934 been commented out. Unless there is activity to revive these
4935 configurations, the next release of GDB will have their sources
4936 permanently REMOVED.
4938 Z8000 simulator z8k-zilog-none or z8ksim
4939 Matsushita MN10200 w/simulator mn10200-*-*
4940 H8/500 simulator h8500-hitachi-hms or h8500hms
4941 HP/PA running BSD hppa*-*-bsd*
4942 HP/PA running OSF/1 hppa*-*-osf*
4943 HP/PA Pro target hppa*-*-pro*
4944 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4945 Sequent family i[3456]86-sequent-sysv4*
4946 i[3456]86-sequent-sysv*
4947 i[3456]86-sequent-bsd*
4948 Tsqware Sparclet sparclet-*-*
4949 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4951 * REMOVED configurations and files
4954 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4955 IBM AIX PS/2 i[3456]86-*-aix
4956 i386 running Mach 3.0 i[3456]86-*-mach3*
4957 i386 running Mach i[3456]86-*-mach*
4958 i386 running OSF/1 i[3456]86-*osf1mk*
4959 HP/Apollo 68k Family m68*-apollo*-sysv*,
4961 m68*-hp-bsd*, m68*-hp-hpux*
4962 Argonaut Risc Chip (ARC) arc-*-*
4963 Mitsubishi D30V d30v-*-*
4964 Fujitsu FR30 fr30-*-elf*
4965 OS/9000 i[34]86-*-os9k
4966 I960 with MON960 i960-*-coff
4968 * MIPS $fp behavior changed
4970 The convenience variable $fp, for the MIPS, now consistently returns
4971 the address of the current frame's base. Previously, depending on the
4972 context, $fp could refer to either $sp or the current frame's base
4973 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4974 The GNU Source-Level Debugger''.
4976 *** Changes in GDB 5.3:
4978 * GNU/Linux shared library multi-threaded performance improved.
4980 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4981 `/proc', in preference to `ptrace' for memory reads. This may result
4982 in an improvement in the start-up time of multi-threaded, shared
4983 library applications when run under GDB. One GDB user writes: ``loads
4984 shared libs like mad''.
4986 * ``gdbserver'' now supports multi-threaded applications on some targets
4988 Support for debugging multi-threaded applications which use
4989 the GNU/Linux LinuxThreads package has been added for
4990 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4991 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4993 * GDB now supports C/C++ preprocessor macros.
4995 GDB now expands preprocessor macro invocations in C/C++ expressions,
4996 and provides various commands for showing macro definitions and how
4999 The new command `macro expand EXPRESSION' expands any macro
5000 invocations in expression, and shows the result.
5002 The new command `show macro MACRO-NAME' shows the definition of the
5003 macro named MACRO-NAME, and where it was defined.
5005 Most compilers don't include information about macros in the debugging
5006 information by default. In GCC 3.1, for example, you need to compile
5007 your program with the options `-gdwarf-2 -g3'. If the macro
5008 information is present in the executable, GDB will read it.
5010 * Multi-arched targets.
5012 DEC Alpha (partial) alpha*-*-*
5013 DEC VAX (partial) vax-*-*
5015 National Semiconductor NS32000 (partial) ns32k-*-*
5016 Motorola 68000 (partial) m68k-*-*
5017 Motorola MCORE mcore-*-*
5021 Fujitsu FRV architecture added by Red Hat frv*-*-*
5024 * New native configurations
5026 Alpha NetBSD alpha*-*-netbsd*
5027 SH NetBSD sh*-*-netbsdelf*
5028 MIPS NetBSD mips*-*-netbsd*
5029 UltraSPARC NetBSD sparc64-*-netbsd*
5031 * OBSOLETE configurations and files
5033 Configurations that have been declared obsolete in this release have
5034 been commented out. Unless there is activity to revive these
5035 configurations, the next release of GDB will have their sources
5036 permanently REMOVED.
5038 Mitsubishi D30V d30v-*-*
5039 OS/9000 i[34]86-*-os9k
5040 IBM AIX PS/2 i[3456]86-*-aix
5041 Fujitsu FR30 fr30-*-elf*
5042 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5043 Argonaut Risc Chip (ARC) arc-*-*
5044 i386 running Mach 3.0 i[3456]86-*-mach3*
5045 i386 running Mach i[3456]86-*-mach*
5046 i386 running OSF/1 i[3456]86-*osf1mk*
5047 HP/Apollo 68k Family m68*-apollo*-sysv*,
5049 m68*-hp-bsd*, m68*-hp-hpux*
5050 I960 with MON960 i960-*-coff
5052 * OBSOLETE languages
5054 CHILL, a Pascal like language used by telecommunications companies.
5056 * REMOVED configurations and files
5058 AMD 29k family via UDI a29k-amd-udi, udi29k
5059 A29K VxWorks a29k-*-vxworks
5060 AMD 29000 embedded, using EBMON a29k-none-none
5061 AMD 29000 embedded with COFF a29k-none-coff
5062 AMD 29000 embedded with a.out a29k-none-aout
5064 testsuite/gdb.hp/gdb.threads-hp/ directory
5066 * New command "set max-user-call-depth <nnn>"
5068 This command allows the user to limit the call depth of user-defined
5069 commands. The default is 1024.
5071 * Changes in FreeBSD/i386 native debugging.
5073 Support for the "generate-core-file" has been added.
5075 * New commands "dump", "append", and "restore".
5077 These commands allow data to be copied from target memory
5078 to a bfd-format or binary file (dump and append), and back
5079 from a file into memory (restore).
5081 * Improved "next/step" support on multi-processor Alpha Tru64.
5083 The previous single-step mechanism could cause unpredictable problems,
5084 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5085 of a software single-step mechanism prevents this.
5087 *** Changes in GDB 5.2.1:
5095 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5096 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5097 Fix, by Joel Brobecker imported from mainline.
5099 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5100 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5101 Fix, by Fred Fish, imported from mainline.
5103 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5104 Surprisingly enough, it works now.
5105 By Michal Ludvig, imported from mainline.
5107 i386 hardware watchpoint support:
5108 avoid misses on second run for some targets.
5109 By Pierre Muller, imported from mainline.
5111 *** Changes in GDB 5.2:
5113 * New command "set trust-readonly-sections on[off]".
5115 This command is a hint that tells gdb that read-only sections
5116 really are read-only (ie. that their contents will not change).
5117 In this mode, gdb will go to the object file rather than the
5118 target to read memory from read-only sections (such as ".text").
5119 This can be a significant performance improvement on some
5120 (notably embedded) targets.
5122 * New command "generate-core-file" (or "gcore").
5124 This new gdb command allows the user to drop a core file of the child
5125 process state at any time. So far it's been implemented only for
5126 GNU/Linux and Solaris, but should be relatively easily ported to other
5127 hosts. Argument is core file name (defaults to core.<pid>).
5129 * New command line option
5131 GDB now accepts --pid or -p followed by a process id.
5133 * Change in command line behavior -- corefiles vs. process ids.
5135 There is a subtle behavior in the way in which GDB handles
5136 command line arguments. The first non-flag argument is always
5137 a program to debug, but the second non-flag argument may either
5138 be a corefile or a process id. Previously, GDB would attempt to
5139 open the second argument as a corefile, and if that failed, would
5140 issue a superfluous error message and then attempt to attach it as
5141 a process. Now, if the second argument begins with a non-digit,
5142 it will be treated as a corefile. If it begins with a digit,
5143 GDB will attempt to attach it as a process, and if no such process
5144 is found, will then attempt to open it as a corefile.
5146 * Changes in ARM configurations.
5148 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5149 configuration is fully multi-arch.
5151 * New native configurations
5153 ARM NetBSD arm*-*-netbsd*
5154 x86 OpenBSD i[3456]86-*-openbsd*
5155 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5156 Sparc64 running FreeBSD sparc64-*-freebsd*
5160 Sanyo XStormy16 xstormy16-elf
5162 * OBSOLETE configurations and files
5164 Configurations that have been declared obsolete in this release have
5165 been commented out. Unless there is activity to revive these
5166 configurations, the next release of GDB will have their sources
5167 permanently REMOVED.
5169 AMD 29k family via UDI a29k-amd-udi, udi29k
5170 A29K VxWorks a29k-*-vxworks
5171 AMD 29000 embedded, using EBMON a29k-none-none
5172 AMD 29000 embedded with COFF a29k-none-coff
5173 AMD 29000 embedded with a.out a29k-none-aout
5175 testsuite/gdb.hp/gdb.threads-hp/ directory
5177 * REMOVED configurations and files
5179 TI TMS320C80 tic80-*-*
5181 PowerPC Solaris powerpcle-*-solaris*
5182 PowerPC Windows NT powerpcle-*-cygwin32
5183 PowerPC Netware powerpc-*-netware*
5184 Harris/CXUX m88k m88*-harris-cxux*
5185 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5186 ns32k-utek-sysv* ns32k-utek-*
5187 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5188 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5189 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5190 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5191 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5193 * Changes to command line processing
5195 The new `--args' feature can be used to specify command-line arguments
5196 for the inferior from gdb's command line.
5198 * Changes to key bindings
5200 There is a new `operate-and-get-next' function bound to `C-o'.
5202 *** Changes in GDB 5.1.1
5204 Fix compile problem on DJGPP.
5206 Fix a problem with floating-point registers on the i386 being
5209 Fix to stop GDB crashing on .debug_str debug info.
5211 Numerous documentation fixes.
5213 Numerous testsuite fixes.
5215 *** Changes in GDB 5.1:
5217 * New native configurations
5219 Alpha FreeBSD alpha*-*-freebsd*
5220 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5221 MIPS GNU/Linux mips*-*-linux*
5222 MIPS SGI Irix 6.x mips*-sgi-irix6*
5223 ia64 AIX ia64-*-aix*
5224 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5228 Motorola 68HC11 and 68HC12 m68hc11-elf
5230 UltraSparc running GNU/Linux sparc64-*-linux*
5232 * OBSOLETE configurations and files
5234 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5235 Harris/CXUX m88k m88*-harris-cxux*
5236 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5237 ns32k-utek-sysv* ns32k-utek-*
5238 TI TMS320C80 tic80-*-*
5240 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5241 PowerPC Solaris powerpcle-*-solaris*
5242 PowerPC Windows NT powerpcle-*-cygwin32
5243 PowerPC Netware powerpc-*-netware*
5244 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5245 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5246 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5247 Apple Macintosh (MPW) host N/A
5249 stuff.c (Program to stuff files into a specially prepared space in kdb)
5250 kdb-start.c (Main loop for the standalone kernel debugger)
5252 Configurations that have been declared obsolete in this release have
5253 been commented out. Unless there is activity to revive these
5254 configurations, the next release of GDB will have their sources
5255 permanently REMOVED.
5257 * REMOVED configurations and files
5259 Altos 3068 m68*-altos-*
5260 Convex c1-*-*, c2-*-*
5262 ARM RISCix arm-*-* (as host)
5266 * GDB has been converted to ISO C.
5268 GDB's source code has been converted to ISO C. In particular, the
5269 sources are fully protoized, and rely on standard headers being
5274 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5276 * The MI enabled by default.
5278 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5279 revised and enabled by default. Packages which use GDB as a debugging
5280 engine behind a UI or another front end are encouraged to switch to
5281 using the GDB/MI interface, instead of the old annotations interface
5282 which is now deprecated.
5284 * Support for debugging Pascal programs.
5286 GDB now includes support for debugging Pascal programs. The following
5287 main features are supported:
5289 - Pascal-specific data types such as sets;
5291 - automatic recognition of Pascal sources based on file-name
5294 - Pascal-style display of data types, variables, and functions;
5296 - a Pascal expression parser.
5298 However, some important features are not yet supported.
5300 - Pascal string operations are not supported at all;
5302 - there are some problems with boolean types;
5304 - Pascal type hexadecimal constants are not supported
5305 because they conflict with the internal variables format;
5307 - support for Pascal objects and classes is not full yet;
5309 - unlike Pascal, GDB is case-sensitive for symbol names.
5311 * Changes in completion.
5313 Commands such as `shell', `run' and `set args', which pass arguments
5314 to inferior programs, now complete on file names, similar to what
5315 users expect at the shell prompt.
5317 Commands which accept locations, such as `disassemble', `print',
5318 `breakpoint', `until', etc. now complete on filenames as well as
5319 program symbols. Thus, if you type "break foob TAB", and the source
5320 files linked into the programs include `foobar.c', that file name will
5321 be one of the candidates for completion. However, file names are not
5322 considered for completion after you typed a colon that delimits a file
5323 name from a name of a function in that file, as in "break foo.c:bar".
5325 `set demangle-style' completes on available demangling styles.
5327 * New platform-independent commands:
5329 It is now possible to define a post-hook for a command as well as a
5330 hook that runs before the command. For more details, see the
5331 documentation of `hookpost' in the GDB manual.
5333 * Changes in GNU/Linux native debugging.
5335 Support for debugging multi-threaded programs has been completely
5336 revised for all platforms except m68k and sparc. You can now debug as
5337 many threads as your system allows you to have.
5339 Attach/detach is supported for multi-threaded programs.
5341 Support for SSE registers was added for x86. This doesn't work for
5342 multi-threaded programs though.
5344 * Changes in MIPS configurations.
5346 Multi-arch support is enabled for all MIPS configurations.
5348 GDB can now be built as native debugger on SGI Irix 6.x systems for
5349 debugging n32 executables. (Debugging 64-bit executables is not yet
5352 * Unified support for hardware watchpoints in all x86 configurations.
5354 Most (if not all) native x86 configurations support hardware-assisted
5355 breakpoints and watchpoints in a unified manner. This support
5356 implements debug register sharing between watchpoints, which allows to
5357 put a virtually infinite number of watchpoints on the same address,
5358 and also supports watching regions up to 16 bytes with several debug
5361 The new maintenance command `maintenance show-debug-regs' toggles
5362 debugging print-outs in functions that insert, remove, and test
5363 watchpoints and hardware breakpoints.
5365 * Changes in the DJGPP native configuration.
5367 New command ``info dos sysinfo'' displays assorted information about
5368 the CPU, OS, memory, and DPMI server.
5370 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5371 display information about segment descriptors stored in GDT, LDT, and
5374 New commands ``info dos pde'' and ``info dos pte'' display entries
5375 from Page Directory and Page Tables (for now works with CWSDPMI only).
5376 New command ``info dos address-pte'' displays the Page Table entry for
5377 a given linear address.
5379 GDB can now pass command lines longer than 126 characters to the
5380 program being debugged (requires an update to the libdbg.a library
5381 which is part of the DJGPP development kit).
5383 DWARF2 debug info is now supported.
5385 It is now possible to `step' and `next' through calls to `longjmp'.
5387 * Changes in documentation.
5389 All GDB documentation was converted to GFDL, the GNU Free
5390 Documentation License.
5392 Tracepoints-related commands are now fully documented in the GDB
5395 TUI, the Text-mode User Interface, is now documented in the manual.
5397 Tracepoints-related commands are now fully documented in the GDB
5400 The "GDB Internals" manual now has an index. It also includes
5401 documentation of `ui_out' functions, GDB coding standards, x86
5402 hardware watchpoints, and memory region attributes.
5404 * GDB's version number moved to ``version.in''
5406 The Makefile variable VERSION has been replaced by the file
5407 ``version.in''. People creating GDB distributions should update the
5408 contents of this file.
5412 GUD support is now a standard part of the EMACS distribution.
5414 *** Changes in GDB 5.0:
5416 * Improved support for debugging FP programs on x86 targets
5418 Unified and much-improved support for debugging floating-point
5419 programs on all x86 targets. In particular, ``info float'' now
5420 displays the FP registers in the same format on all x86 targets, with
5421 greater level of detail.
5423 * Improvements and bugfixes in hardware-assisted watchpoints
5425 It is now possible to watch array elements, struct members, and
5426 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5427 on x86 targets no longer erroneously trigger when the address is
5430 * Improvements in the native DJGPP version of GDB
5432 The distribution now includes all the scripts and auxiliary files
5433 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5434 machines ``out of the box''.
5436 The DJGPP version can now debug programs that use signals. It is
5437 possible to catch signals that happened in the debuggee, deliver
5438 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5439 would kill the program being debugged.) Programs that hook hardware
5440 interrupts (keyboard, timer, etc.) can also be debugged.
5442 It is now possible to debug DJGPP programs that redirect their
5443 standard handles or switch them to raw (as opposed to cooked) mode, or
5444 even close them. The command ``run < foo > bar'' works as expected,
5445 and ``info terminal'' reports useful information about the debuggee's
5446 terminal, including raw/cooked mode, redirection, etc.
5448 The DJGPP version now uses termios functions for console I/O, which
5449 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5452 DOS-style file names with drive letters are now fully supported by
5455 It is now possible to debug DJGPP programs that switch their working
5456 directory. It is also possible to rerun the debuggee any number of
5457 times without restarting GDB; thus, you can use the same setup,
5458 breakpoints, etc. for many debugging sessions.
5460 * New native configurations
5462 ARM GNU/Linux arm*-*-linux*
5463 PowerPC GNU/Linux powerpc-*-linux*
5467 Motorola MCore mcore-*-*
5468 x86 VxWorks i[3456]86-*-vxworks*
5469 PowerPC VxWorks powerpc-*-vxworks*
5470 TI TMS320C80 tic80-*-*
5472 * OBSOLETE configurations
5474 Altos 3068 m68*-altos-*
5475 Convex c1-*-*, c2-*-*
5477 ARM RISCix arm-*-* (as host)
5480 Configurations that have been declared obsolete will be commented out,
5481 but the code will be left in place. If there is no activity to revive
5482 these configurations before the next release of GDB, the sources will
5483 be permanently REMOVED.
5485 * Gould support removed
5487 Support for the Gould PowerNode and NP1 has been removed.
5489 * New features for SVR4
5491 On SVR4 native platforms (such as Solaris), if you attach to a process
5492 without first loading a symbol file, GDB will now attempt to locate and
5493 load symbols from the running process's executable file.
5495 * Many C++ enhancements
5497 C++ support has been greatly improved. Overload resolution now works properly
5498 in almost all cases. RTTI support is on the way.
5500 * Remote targets can connect to a sub-program
5502 A popen(3) style serial-device has been added. This device starts a
5503 sub-process (such as a stand-alone simulator) and then communicates
5504 with that. The sub-program to run is specified using the syntax
5505 ``|<program> <args>'' vis:
5507 (gdb) set remotedebug 1
5508 (gdb) target extended-remote |mn10300-elf-sim program-args
5510 * MIPS 64 remote protocol
5512 A long standing bug in the mips64 remote protocol where by GDB
5513 expected certain 32 bit registers (ex SR) to be transfered as 32
5514 instead of 64 bits has been fixed.
5516 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5517 added to provide backward compatibility with older versions of GDB.
5519 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5521 The command ``set remotebinarydownload'' command has been replaced by
5522 ``set remote X-packet''. Other commands in ``set remote'' family
5523 include ``set remote P-packet''.
5525 * Breakpoint commands accept ranges.
5527 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5528 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5529 ``tracepoint passcount'' also accepts a range of tracepoints.
5531 * ``apropos'' command added.
5533 The ``apropos'' command searches through command names and
5534 documentation strings, printing out matches, making it much easier to
5535 try to find a command that does what you are looking for.
5539 A new machine oriented interface (MI) has been added to GDB. This
5540 interface is designed for debug environments running GDB as a separate
5541 process. This is part of the long term libGDB project. See the
5542 "GDB/MI" chapter of the GDB manual for further information. It can be
5543 enabled by configuring with:
5545 .../configure --enable-gdbmi
5547 *** Changes in GDB-4.18:
5549 * New native configurations
5551 HP-UX 10.20 hppa*-*-hpux10.20
5552 HP-UX 11.x hppa*-*-hpux11.0*
5553 M68K GNU/Linux m68*-*-linux*
5557 Fujitsu FR30 fr30-*-elf*
5558 Intel StrongARM strongarm-*-*
5559 Mitsubishi D30V d30v-*-*
5561 * OBSOLETE configurations
5563 Gould PowerNode, NP1 np1-*-*, pn-*-*
5565 Configurations that have been declared obsolete will be commented out,
5566 but the code will be left in place. If there is no activity to revive
5567 these configurations before the next release of GDB, the sources will
5568 be permanently REMOVED.
5572 As a compatibility experiment, GDB's source files buildsym.h and
5573 buildsym.c have been converted to pure standard C, no longer
5574 containing any K&R compatibility code. We believe that all systems in
5575 use today either come with a standard C compiler, or have a GCC port
5576 available. If this is not true, please report the affected
5577 configuration to bug-gdb@gnu.org immediately. See the README file for
5578 information about getting a standard C compiler if you don't have one
5583 GDB now uses readline 2.2.
5585 * set extension-language
5587 You can now control the mapping between filename extensions and source
5588 languages by using the `set extension-language' command. For instance,
5589 you can ask GDB to treat .c files as C++ by saying
5590 set extension-language .c c++
5591 The command `info extensions' lists all of the recognized extensions
5592 and their associated languages.
5594 * Setting processor type for PowerPC and RS/6000
5596 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5597 you can use the `set processor' command to specify what variant of the
5598 PowerPC family you are debugging. The command
5602 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5603 following PowerPC and RS6000 variants:
5605 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5606 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5608 403GC IBM PowerPC 403GC
5609 505 Motorola PowerPC 505
5610 860 Motorola PowerPC 860 or 850
5611 601 Motorola PowerPC 601
5612 602 Motorola PowerPC 602
5613 603 Motorola/IBM PowerPC 603 or 603e
5614 604 Motorola PowerPC 604 or 604e
5615 750 Motorola/IBM PowerPC 750 or 750
5617 At the moment, this command just tells GDB what to name the
5618 special-purpose processor registers. Since almost all the affected
5619 registers are inaccessible to user-level programs, this command is
5620 only useful for remote debugging in its present form.
5624 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5625 more extensive support for HP-UX. Added features include shared
5626 library support, kernel threads and hardware watchpoints for 11.00,
5627 support for HP's ANSI C and C++ compilers, and a compatibility mode
5628 for xdb and dbx commands.
5632 HP's donation includes the new concept of catchpoints, which is a
5633 generalization of the old catch command. On HP-UX, it is now possible
5634 to catch exec, fork, and vfork, as well as library loading.
5636 This means that the existing catch command has changed; its first
5637 argument now specifies the type of catch to be set up. See the
5638 output of "help catch" for a list of catchpoint types.
5640 * Debugging across forks
5642 On HP-UX, you can choose which process to debug when a fork() happens
5647 HP has donated a curses-based terminal user interface (TUI). To get
5648 it, build with --enable-tui. Although this can be enabled for any
5649 configuration, at present it only works for native HP debugging.
5651 * GDB remote protocol additions
5653 A new protocol packet 'X' that writes binary data is now available.
5654 Default behavior is to try 'X', then drop back to 'M' if the stub
5655 fails to respond. The settable variable `remotebinarydownload'
5656 allows explicit control over the use of 'X'.
5658 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5659 full 64-bit address. The command
5661 set remoteaddresssize 32
5663 can be used to revert to the old behaviour. For existing remote stubs
5664 the change should not be noticed, as the additional address information
5667 In order to assist in debugging stubs, you may use the maintenance
5668 command `packet' to send any text string to the stub. For instance,
5670 maint packet heythere
5672 sends the packet "$heythere#<checksum>". Note that it is very easy to
5673 disrupt a debugging session by sending the wrong packet at the wrong
5676 The compare-sections command allows you to compare section data on the
5677 target to what is in the executable file without uploading or
5678 downloading, by comparing CRC checksums.
5680 * Tracing can collect general expressions
5682 You may now collect general expressions at tracepoints. This requires
5683 further additions to the target-side stub; see tracepoint.c and
5684 doc/agentexpr.texi for further details.
5686 * mask-address variable for Mips
5688 For Mips targets, you may control the zeroing of the upper 32 bits of
5689 a 64-bit address by entering `set mask-address on'. This is mainly
5690 of interest to users of embedded R4xxx and R5xxx processors.
5692 * Higher serial baud rates
5694 GDB's serial code now allows you to specify baud rates 57600, 115200,
5695 230400, and 460800 baud. (Note that your host system may not be able
5696 to achieve all of these rates.)
5700 The i960 configuration now includes an initial implementation of a
5701 builtin simulator, contributed by Jim Wilson.
5704 *** Changes in GDB-4.17:
5706 * New native configurations
5708 Alpha GNU/Linux alpha*-*-linux*
5709 Unixware 2.x i[3456]86-unixware2*
5710 Irix 6.x mips*-sgi-irix6*
5711 PowerPC GNU/Linux powerpc-*-linux*
5712 PowerPC Solaris powerpcle-*-solaris*
5713 Sparc GNU/Linux sparc-*-linux*
5714 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5718 Argonaut Risc Chip (ARC) arc-*-*
5719 Hitachi H8/300S h8300*-*-*
5720 Matsushita MN10200 w/simulator mn10200-*-*
5721 Matsushita MN10300 w/simulator mn10300-*-*
5722 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5723 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5724 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5725 Mitsubishi D10V w/simulator d10v-*-*
5726 Mitsubishi M32R/D w/simulator m32r-*-elf*
5727 Tsqware Sparclet sparclet-*-*
5728 NEC V850 w/simulator v850-*-*
5730 * New debugging protocols
5732 ARM with RDI protocol arm*-*-*
5733 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5734 DDB and LSI variants of PMON protocol mips*-*-*
5735 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5736 PowerPC with SDS protocol powerpc{,le}-*-eabi
5737 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5741 All configurations can now understand and use the DWARF 2 debugging
5742 format. The choice is automatic, if the symbol file contains DWARF 2
5747 GDB now includes basic Java language support. This support is
5748 only useful with Java compilers that produce native machine code.
5750 * solib-absolute-prefix and solib-search-path
5752 For SunOS and SVR4 shared libraries, you may now set the prefix for
5753 loading absolute shared library symbol files, and the search path for
5754 locating non-absolute shared library symbol files.
5756 * Live range splitting
5758 GDB can now effectively debug code for which GCC has performed live
5759 range splitting as part of its optimization. See gdb/doc/LRS for
5760 more details on the expected format of the stabs information.
5764 GDB's support for the GNU Hurd, including thread debugging, has been
5765 updated to work with current versions of the Hurd.
5769 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5770 instruction set. ARM GDB automatically detects when Thumb
5771 instructions are in use, and adjusts disassembly and backtracing
5776 GDB's MIPS target configurations now handle the MIP16 16-bit
5781 GDB now includes support for overlays; if an executable has been
5782 linked such that multiple sections are based at the same address, GDB
5783 will decide which section to use for symbolic info. You can choose to
5784 control the decision manually, using overlay commands, or implement
5785 additional target-side support and use "overlay load-target" to bring
5786 in the overlay mapping. Do "help overlay" for more detail.
5790 The command "info symbol <address>" displays information about
5791 the symbol at the specified address.
5795 The standard remote protocol now includes an extension that allows
5796 asynchronous collection and display of trace data. This requires
5797 extensive support in the target-side debugging stub. Tracing mode
5798 includes a new interaction mode in GDB and new commands: see the
5799 file tracepoint.c for more details.
5803 Configurations for embedded MIPS now include a simulator contributed
5804 by Cygnus Solutions. The simulator supports the instruction sets
5805 of most MIPS variants.
5809 Sparc configurations may now include the ERC32 simulator contributed
5810 by the European Space Agency. The simulator is not built into
5811 Sparc targets by default; configure with --enable-sim to include it.
5815 For target configurations that may include multiple variants of a
5816 basic architecture (such as MIPS and SH), you may now set the
5817 architecture explicitly. "set arch" sets, "info arch" lists
5818 the possible architectures.
5820 *** Changes in GDB-4.16:
5822 * New native configurations
5824 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5825 M68K NetBSD m68k-*-netbsd*
5826 PowerPC AIX 4.x powerpc-*-aix*
5827 PowerPC MacOS powerpc-*-macos*
5828 PowerPC Windows NT powerpcle-*-cygwin32
5829 RS/6000 AIX 4.x rs6000-*-aix4*
5833 ARM with RDP protocol arm-*-*
5834 I960 with MON960 i960-*-coff
5835 MIPS VxWorks mips*-*-vxworks*
5836 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5837 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5839 Matra Sparclet sparclet-*-*
5843 The powerpc-eabi configuration now includes the PSIM simulator,
5844 contributed by Andrew Cagney, with assistance from Mike Meissner.
5845 PSIM is a very elaborate model of the PowerPC, including not only
5846 basic instruction set execution, but also details of execution unit
5847 performance and I/O hardware. See sim/ppc/README for more details.
5851 GDB now works with Solaris 2.5.
5853 * Windows 95/NT native
5855 GDB will now work as a native debugger on Windows 95 and Windows NT.
5856 To build it from source, you must use the "gnu-win32" environment,
5857 which uses a DLL to emulate enough of Unix to run the GNU tools.
5858 Further information, binaries, and sources are available at
5859 ftp.cygnus.com, under pub/gnu-win32.
5861 * dont-repeat command
5863 If a user-defined command includes the command `dont-repeat', then the
5864 command will not be repeated if the user just types return. This is
5865 useful if the command is time-consuming to run, so that accidental
5866 extra keystrokes don't run the same command many times.
5868 * Send break instead of ^C
5870 The standard remote protocol now includes an option to send a break
5871 rather than a ^C to the target in order to interrupt it. By default,
5872 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5874 * Remote protocol timeout
5876 The standard remote protocol includes a new variable `remotetimeout'
5877 that allows you to set the number of seconds before GDB gives up trying
5878 to read from the target. The default value is 2.
5880 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5882 By default GDB will automatically keep track of objects as they are
5883 loaded and unloaded by the dynamic linker. By using the command `set
5884 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5885 when shared library events occur, thus allowing you to set breakpoints
5886 in shared libraries which are explicitly loaded by the inferior.
5888 Note this feature does not work on hpux8. On hpux9 you must link
5889 /usr/lib/end.o into your program. This feature should work
5890 automatically on hpux10.
5892 * Irix 5.x hardware watchpoint support
5894 Irix 5 configurations now support the use of hardware watchpoints.
5896 * Mips protocol "SYN garbage limit"
5898 When debugging a Mips target using the `target mips' protocol, you
5899 may set the number of characters that GDB will ignore by setting
5900 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5901 every character. The default value is 1050.
5903 * Recording and replaying remote debug sessions
5905 If you set `remotelogfile' to the name of a file, gdb will write to it
5906 a recording of a remote debug session. This recording may then be
5907 replayed back to gdb using "gdbreplay". See gdbserver/README for
5908 details. This is useful when you have a problem with GDB while doing
5909 remote debugging; you can make a recording of the session and send it
5910 to someone else, who can then recreate the problem.
5912 * Speedups for remote debugging
5914 GDB includes speedups for downloading and stepping MIPS systems using
5915 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5916 and more efficient S-record downloading.
5918 * Memory use reductions and statistics collection
5920 GDB now uses less memory and reports statistics about memory usage.
5921 Try the `maint print statistics' command, for example.
5923 *** Changes in GDB-4.15:
5925 * Psymtabs for XCOFF
5927 The symbol reader for AIX GDB now uses partial symbol tables. This
5928 can greatly improve startup time, especially for large executables.
5930 * Remote targets use caching
5932 Remote targets now use a data cache to speed up communication with the
5933 remote side. The data cache could lead to incorrect results because
5934 it doesn't know about volatile variables, thus making it impossible to
5935 debug targets which use memory mapped I/O devices. `set remotecache
5936 off' turns the the data cache off.
5938 * Remote targets may have threads
5940 The standard remote protocol now includes support for multiple threads
5941 in the target system, using new protocol commands 'H' and 'T'. See
5942 gdb/remote.c for details.
5946 If GDB is configured with `--enable-netrom', then it will include
5947 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5948 acts as though it is a bank of ROM on the target board, but you can
5949 write into it over the network. GDB's support consists only of
5950 support for fast loading into the emulated ROM; to debug, you must use
5951 another protocol, such as standard remote protocol. The usual
5952 sequence is something like
5954 target nrom <netrom-hostname>
5956 target remote <netrom-hostname>:1235
5960 GDB now includes support for the Apple Macintosh, as a host only. It
5961 may be run as either an MPW tool or as a standalone application, and
5962 it can debug through the serial port. All the usual GDB commands are
5963 available, but to the target command, you must supply "serial" as the
5964 device type instead of "/dev/ttyXX". See mpw-README in the main
5965 directory for more information on how to build. The MPW configuration
5966 scripts */mpw-config.in support only a few targets, and only the
5967 mips-idt-ecoff target has been tested.
5971 GDB configuration now uses autoconf. This is not user-visible,
5972 but does simplify configuration and building.
5976 GDB now supports hpux10.
5978 *** Changes in GDB-4.14:
5980 * New native configurations
5982 x86 FreeBSD i[345]86-*-freebsd
5983 x86 NetBSD i[345]86-*-netbsd
5984 NS32k NetBSD ns32k-*-netbsd
5985 Sparc NetBSD sparc-*-netbsd
5989 A29K VxWorks a29k-*-vxworks
5990 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5991 CPU32 EST-300 emulator m68*-*-est*
5992 PowerPC ELF powerpc-*-elf
5995 * Alpha OSF/1 support for procfs
5997 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5998 possible to attach to running processes. As the mounting of the /proc
5999 filesystem is optional on the Alpha, GDB automatically determines
6000 the availability of /proc during startup. This can lead to problems
6001 if /proc is unmounted after GDB has been started.
6003 * Arguments to user-defined commands
6005 User commands may accept up to 10 arguments separated by whitespace.
6006 Arguments are accessed within the user command via $arg0..$arg9. A
6009 print $arg0 + $arg1 + $arg2
6011 To execute the command use:
6014 Defines the command "adder" which prints the sum of its three arguments.
6015 Note the arguments are text substitutions, so they may reference variables,
6016 use complex expressions, or even perform inferior function calls.
6018 * New `if' and `while' commands
6020 This makes it possible to write more sophisticated user-defined
6021 commands. Both commands take a single argument, which is the
6022 expression to evaluate, and must be followed by the commands to
6023 execute, one per line, if the expression is nonzero, the list being
6024 terminated by the word `end'. The `if' command list may include an
6025 `else' word, which causes the following commands to be executed only
6026 if the expression is zero.
6028 * Fortran source language mode
6030 GDB now includes partial support for Fortran 77. It will recognize
6031 Fortran programs and can evaluate a subset of Fortran expressions, but
6032 variables and functions may not be handled correctly. GDB will work
6033 with G77, but does not yet know much about symbols emitted by other
6036 * Better HPUX support
6038 Most debugging facilities now work on dynamic executables for HPPAs
6039 running hpux9 or later. You can attach to running dynamically linked
6040 processes, but by default the dynamic libraries will be read-only, so
6041 for instance you won't be able to put breakpoints in them. To change
6042 that behavior do the following before running the program:
6048 This will cause the libraries to be mapped private and read-write.
6049 To revert to the normal behavior, do this:
6055 You cannot set breakpoints or examine data in the library until after
6056 the library is loaded if the function/data symbols do not have
6059 GDB can now also read debug symbols produced by the HP C compiler on
6060 HPPAs (sorry, no C++, Fortran or 68k support).
6062 * Target byte order now dynamically selectable
6064 You can choose which byte order to use with a target system, via the
6065 commands "set endian big" and "set endian little", and you can see the
6066 current setting by using "show endian". You can also give the command
6067 "set endian auto", in which case GDB will use the byte order
6068 associated with the executable. Currently, only embedded MIPS
6069 configurations support dynamic selection of target byte order.
6071 * New DOS host serial code
6073 This version uses DPMI interrupts to handle buffered I/O, so you
6074 no longer need to run asynctsr when debugging boards connected to
6077 *** Changes in GDB-4.13:
6079 * New "complete" command
6081 This lists all the possible completions for the rest of the line, if it
6082 were to be given as a command itself. This is intended for use by emacs.
6084 * Trailing space optional in prompt
6086 "set prompt" no longer adds a space for you after the prompt you set. This
6087 allows you to set a prompt which ends in a space or one that does not.
6089 * Breakpoint hit counts
6091 "info break" now displays a count of the number of times the breakpoint
6092 has been hit. This is especially useful in conjunction with "ignore"; you
6093 can ignore a large number of breakpoint hits, look at the breakpoint info
6094 to see how many times the breakpoint was hit, then run again, ignoring one
6095 less than that number, and this will get you quickly to the last hit of
6098 * Ability to stop printing at NULL character
6100 "set print null-stop" will cause GDB to stop printing the characters of
6101 an array when the first NULL is encountered. This is useful when large
6102 arrays actually contain only short strings.
6104 * Shared library breakpoints
6106 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6107 breakpoints in shared libraries before the executable is run.
6109 * Hardware watchpoints
6111 There is a new hardware breakpoint for the watch command for sparclite
6112 targets. See gdb/sparclite/hw_breakpoint.note.
6114 Hardware watchpoints are also now supported under GNU/Linux.
6118 Annotations have been added. These are for use with graphical interfaces,
6119 and are still experimental. Currently only gdba.el uses these.
6121 * Improved Irix 5 support
6123 GDB now works properly with Irix 5.2.
6125 * Improved HPPA support
6127 GDB now works properly with the latest GCC and GAS.
6129 * New native configurations
6131 Sequent PTX4 i[34]86-sequent-ptx4
6132 HPPA running OSF/1 hppa*-*-osf*
6133 Atari TT running SVR4 m68*-*-sysv4*
6134 RS/6000 LynxOS rs6000-*-lynxos*
6138 OS/9000 i[34]86-*-os9k
6139 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6142 * Hitachi SH7000 and E7000-PC ICE support
6144 There is now support for communicating with the Hitachi E7000-PC ICE.
6145 This is available automatically when GDB is configured for the SH.
6149 As usual, a variety of small fixes and improvements, both generic
6150 and configuration-specific. See the ChangeLog for more detail.
6152 *** Changes in GDB-4.12:
6154 * Irix 5 is now supported
6158 GDB-4.12 on the HPPA has a number of changes which make it unable
6159 to debug the output from the currently released versions of GCC and
6160 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6161 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6162 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6165 *** Changes in GDB-4.11:
6167 * User visible changes:
6171 The "set remotedebug" option is now consistent between the mips remote
6172 target, remote targets using the gdb-specific protocol, UDI (AMD's
6173 debug protocol for the 29k) and the 88k bug monitor. It is now an
6174 integer specifying a debug level (normally 0 or 1, but 2 means more
6175 debugging info for the mips target).
6177 * DEC Alpha native support
6179 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6180 debug info, but GDB works fairly well with the DEC compiler and should
6181 work with a future GCC release. See the README file for a few
6182 Alpha-specific notes.
6184 * Preliminary thread implementation
6186 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6188 * LynxOS native and target support for 386
6190 This release has been hosted on LynxOS 2.2, and also can be configured
6191 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6194 * Improvements in C++ mangling/demangling.
6196 This release has much better g++ debugging, specifically in name
6197 mangling/demangling, virtual function calls, print virtual table,
6198 call methods, ...etc.
6200 *** Changes in GDB-4.10:
6202 * User visible changes:
6204 Remote debugging using the GDB-specific (`target remote') protocol now
6205 supports the `load' command. This is only useful if you have some
6206 other way of getting the stub to the target system, and you can put it
6207 somewhere in memory where it won't get clobbered by the download.
6209 Filename completion now works.
6211 When run under emacs mode, the "info line" command now causes the
6212 arrow to point to the line specified. Also, "info line" prints
6213 addresses in symbolic form (as well as hex).
6215 All vxworks based targets now support a user settable option, called
6216 vxworks-timeout. This option represents the number of seconds gdb
6217 should wait for responses to rpc's. You might want to use this if
6218 your vxworks target is, perhaps, a slow software simulator or happens
6219 to be on the far side of a thin network line.
6223 This release contains support for using a DEC alpha as a GDB host for
6224 cross debugging. Native alpha debugging is not supported yet.
6227 *** Changes in GDB-4.9:
6231 This is the first GDB release which is accompanied by a matching testsuite.
6232 The testsuite requires installation of dejagnu, which should be available
6233 via ftp from most sites that carry GNU software.
6237 'Cfront' style demangling has had its name changed to 'ARM' style, to
6238 emphasize that it was written from the specifications in the C++ Annotated
6239 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6240 disclaimers, it still generated too much confusion with users attempting to
6241 use gdb with AT&T cfront.
6245 GDB now uses a standard remote interface to a simulator library.
6246 So far, the library contains simulators for the Zilog Z8001/2, the
6247 Hitachi H8/300, H8/500 and Super-H.
6249 * New targets supported
6251 H8/300 simulator h8300-hitachi-hms or h8300hms
6252 H8/500 simulator h8500-hitachi-hms or h8500hms
6253 SH simulator sh-hitachi-hms or sh
6254 Z8000 simulator z8k-zilog-none or z8ksim
6255 IDT MIPS board over serial line mips-idt-ecoff
6257 Cross-debugging to GO32 targets is supported. It requires a custom
6258 version of the i386-stub.c module which is integrated with the
6259 GO32 memory extender.
6261 * New remote protocols
6263 MIPS remote debugging protocol.
6265 * New source languages supported
6267 This version includes preliminary support for Chill, a Pascal like language
6268 used by telecommunications companies. Chill support is also being integrated
6269 into the GNU compiler, but we don't know when it will be publically available.
6272 *** Changes in GDB-4.8:
6274 * HP Precision Architecture supported
6276 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6277 version of this support was available as a set of patches from the
6278 University of Utah. GDB does not support debugging of programs
6279 compiled with the HP compiler, because HP will not document their file
6280 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6281 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6283 Many problems in the preliminary version have been fixed.
6285 * Faster and better demangling
6287 We have improved template demangling and fixed numerous bugs in the GNU style
6288 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6289 character types (wchar_t) are now supported. Demangling of each symbol is now
6290 only done once, and is cached when the symbol table for a file is read in.
6291 This results in a small increase in memory usage for C programs, a moderate
6292 increase in memory usage for C++ programs, and a fantastic speedup in
6295 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6296 from the specifications in the Annotated Reference Manual, which AT&T's
6297 compiler does not actually implement.
6299 * G++ multiple inheritance compiler problem
6301 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6302 inheritance lattices was reworked to properly discover ambiguities. We
6303 recently found an example which causes this new algorithm to fail in a
6304 very subtle way, producing bad debug information for those classes.
6305 The file 'gcc.patch' (in this directory) can be applied to gcc to
6306 circumvent the problem. A future GCC release will contain a complete
6309 The previous G++ debug info problem (mentioned below for the gdb-4.7
6310 release) is fixed in gcc version 2.3.2.
6312 * Improved configure script
6314 The `configure' script will now attempt to guess your system type if
6315 you don't supply a host system type. The old scheme of supplying a
6316 host system triplet is preferable over using this. All the magic is
6317 done in the new `config.guess' script. Examine it for details.
6319 We have also brought our configure script much more in line with the FSF's
6320 version. It now supports the --with-xxx options. In particular,
6321 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6322 The resulting GDB will not be able to read arbitrary object file formats --
6323 only the format ``expected'' to be used on the configured target system.
6324 We hope to make this the default in a future release.
6326 * Documentation improvements
6328 There's new internal documentation on how to modify GDB, and how to
6329 produce clean changes to the code. We implore people to read it
6330 before submitting changes.
6332 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6333 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6334 `info' files are also provided. To build `info' files from scratch,
6335 you will need the latest `makeinfo' release, which will be available in
6336 a future texinfo-X.Y release.
6338 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6339 We're not sure exactly which versions have this problem, but it has
6340 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6341 or better. If that isn't possible, there is a patch in
6342 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6343 around this problem.
6347 GDB now supports array constants that can be used in expressions typed in by
6348 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6349 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6352 The new directory `gdb/sparclite' contains a program that demonstrates
6353 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6355 * New native hosts supported
6357 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6358 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6360 * New targets supported
6362 AMD 29k family via UDI a29k-amd-udi or udi29k
6364 * New file formats supported
6366 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6367 HPUX core files, and SCO 3.2v2 core files.
6371 Attaching to processes now works again; thanks for the many bug reports.
6373 We have also stomped on a bunch of core dumps caused by
6374 printf_filtered("%s") problems.
6376 We eliminated a copyright problem on the rpc and ptrace header files
6377 for VxWorks, which was discovered at the last minute during the 4.7
6378 release. You should now be able to build a VxWorks GDB.
6380 You can now interrupt gdb while an attached process is running. This
6381 will cause the attached process to stop, and give control back to GDB.
6383 We fixed problems caused by using too many file descriptors
6384 for reading symbols from object files and libraries. This was
6385 especially a problem for programs that used many (~100) shared
6388 The `step' command now only enters a subroutine if there is line number
6389 information for the subroutine. Otherwise it acts like the `next'
6390 command. Previously, `step' would enter subroutines if there was
6391 any debugging information about the routine. This avoids problems
6392 when using `cc -g1' on MIPS machines.
6394 * Internal improvements
6396 GDB's internal interfaces have been improved to make it easier to support
6397 debugging of multiple languages in the future.
6399 GDB now uses a common structure for symbol information internally.
6400 Minimal symbols (derived from linkage symbols in object files), partial
6401 symbols (from a quick scan of debug information), and full symbols
6402 contain a common subset of information, making it easier to write
6403 shared code that handles any of them.
6405 * New command line options
6407 We now accept --silent as an alias for --quiet.
6411 The memory-mapped-malloc library is now licensed under the GNU Library
6412 General Public License.
6414 *** Changes in GDB-4.7:
6416 * Host/native/target split
6418 GDB has had some major internal surgery to untangle the support for
6419 hosts and remote targets. Now, when you configure GDB for a remote
6420 target, it will no longer load in all of the support for debugging
6421 local programs on the host. When fully completed and tested, this will
6422 ensure that arbitrary host/target combinations are possible.
6424 The primary conceptual shift is to separate the non-portable code in
6425 GDB into three categories. Host specific code is required any time GDB
6426 is compiled on that host, regardless of the target. Target specific
6427 code relates to the peculiarities of the target, but can be compiled on
6428 any host. Native specific code is everything else: it can only be
6429 built when the host and target are the same system. Child process
6430 handling and core file support are two common `native' examples.
6432 GDB's use of /proc for controlling Unix child processes is now cleaner.
6433 It has been split out into a single module under the `target_ops' vector,
6434 plus two native-dependent functions for each system that uses /proc.
6436 * New hosts supported
6438 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6439 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6440 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6442 * New targets supported
6444 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6445 68030 and CPU32 m68030-*-*, m68332-*-*
6447 * New native hosts supported
6449 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6450 (386bsd is not well tested yet)
6451 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6453 * New file formats supported
6455 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6456 supports reading of `a.out.adobe' object files, which are an a.out
6457 format extended with minimal information about multiple sections.
6461 `show copying' is the same as the old `info copying'.
6462 `show warranty' is the same as `info warrantee'.
6463 These were renamed for consistency. The old commands continue to work.
6465 `info handle' is a new alias for `info signals'.
6467 You can now define pre-command hooks, which attach arbitrary command
6468 scripts to any command. The commands in the hook will be executed
6469 prior to the user's command. You can also create a hook which will be
6470 executed whenever the program stops. See gdb.texinfo.
6474 We now deal with Cfront style name mangling, and can even extract type
6475 info from mangled symbols. GDB can automatically figure out which
6476 symbol mangling style your C++ compiler uses.
6478 Calling of methods and virtual functions has been improved as well.
6482 The crash that occured when debugging Sun Ansi-C compiled binaries is
6483 fixed. This was due to mishandling of the extra N_SO stabs output
6486 We also finally got Ultrix 4.2 running in house, and fixed core file
6487 support, with help from a dozen people on the net.
6489 John M. Farrell discovered that the reason that single-stepping was so
6490 slow on all of the Mips based platforms (primarily SGI and DEC) was
6491 that we were trying to demangle and lookup a symbol used for internal
6492 purposes on every instruction that was being stepped through. Changing
6493 the name of that symbol so that it couldn't be mistaken for a C++
6494 mangled symbol sped things up a great deal.
6496 Rich Pixley sped up symbol lookups in general by getting much smarter
6497 about when C++ symbol mangling is necessary. This should make symbol
6498 completion (TAB on the command line) much faster. It's not as fast as
6499 we'd like, but it's significantly faster than gdb-4.6.
6503 A new user controllable variable 'call_scratch_address' can
6504 specify the location of a scratch area to be used when GDB
6505 calls a function in the target. This is necessary because the
6506 usual method of putting the scratch area on the stack does not work
6507 in systems that have separate instruction and data spaces.
6509 We integrated changes to support the 29k UDI (Universal Debugger
6510 Interface), but discovered at the last minute that we didn't have all
6511 of the appropriate copyright paperwork. We are working with AMD to
6512 resolve this, and hope to have it available soon.
6516 We have sped up the remote serial line protocol, especially for targets
6517 with lots of registers. It now supports a new `expedited status' ('T')
6518 message which can be used in place of the existing 'S' status message.
6519 This allows the remote stub to send only the registers that GDB
6520 needs to make a quick decision about single-stepping or conditional
6521 breakpoints, eliminating the need to fetch the entire register set for
6522 each instruction being stepped through.
6524 The GDB remote serial protocol now implements a write-through cache for
6525 registers, only re-reading the registers if the target has run.
6527 There is also a new remote serial stub for SPARC processors. You can
6528 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6529 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6530 processor with a serial port.
6534 Configure.in files have become much easier to read and modify. A new
6535 `table driven' format makes it more obvious what configurations are
6536 supported, and what files each one uses.
6540 There is a new opcodes library which will eventually contain all of the
6541 disassembly routines and opcode tables. At present, it only contains
6542 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6543 disassembler (binutils/objdump) to share these routines.
6545 The libiberty library is now copylefted under the GNU Library General
6546 Public License. This allows more liberal use, and was done so libg++
6547 can use it. This makes no difference to GDB, since the Library License
6548 grants all the rights from the General Public License.
6552 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6553 reference to the stabs symbol info used by the debugger. It is (as far
6554 as we know) the only published document on this fascinating topic. We
6555 encourage you to read it, compare it to the stabs information on your
6556 system, and send improvements on the document in general (to
6557 bug-gdb@prep.ai.mit.edu).
6559 And, of course, many bugs have been fixed.
6562 *** Changes in GDB-4.6:
6564 * Better support for C++ function names
6566 GDB now accepts as input the "demangled form" of C++ overloaded function
6567 names and member function names, and can do command completion on such names
6568 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6569 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6570 Make use of command completion, it is your friend.
6572 GDB also now accepts a variety of C++ mangled symbol formats. They are
6573 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6574 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6575 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6576 for the list of formats.
6578 * G++ symbol mangling problem
6580 Recent versions of gcc have a bug in how they emit debugging information for
6581 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6582 directory) can be applied to gcc to fix the problem. Alternatively, if you
6583 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6584 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6585 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6588 * New 'maintenance' command
6590 All of the commands related to hacking GDB internals have been moved out of
6591 the main command set, and now live behind the 'maintenance' command. This
6592 can also be abbreviated as 'mt'. The following changes were made:
6594 dump-me -> maintenance dump-me
6595 info all-breakpoints -> maintenance info breakpoints
6596 printmsyms -> maintenance print msyms
6597 printobjfiles -> maintenance print objfiles
6598 printpsyms -> maintenance print psymbols
6599 printsyms -> maintenance print symbols
6601 The following commands are new:
6603 maintenance demangle Call internal GDB demangler routine to
6604 demangle a C++ link name and prints the result.
6605 maintenance print type Print a type chain for a given symbol
6607 * Change to .gdbinit file processing
6609 We now read the $HOME/.gdbinit file before processing the argv arguments
6610 (e.g. reading symbol files or core files). This allows global parameters to
6611 be set, which will apply during the symbol reading. The ./.gdbinit is still
6612 read after argv processing.
6614 * New hosts supported
6616 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6618 GNU/Linux support i386-unknown-linux or linux
6620 We are also including code to support the HP/PA running BSD and HPUX. This
6621 is almost guaranteed not to work, as we didn't have time to test or build it
6622 for this release. We are including it so that the more adventurous (or
6623 masochistic) of you can play with it. We also had major problems with the
6624 fact that the compiler that we got from HP doesn't support the -g option.
6627 * New targets supported
6629 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6631 * More smarts about finding #include files
6633 GDB now remembers the compilation directory for all include files, and for
6634 all files from which C is generated (like yacc and lex sources). This
6635 greatly improves GDB's ability to find yacc/lex sources, and include files,
6636 especially if you are debugging your program from a directory different from
6637 the one that contains your sources.
6639 We also fixed a bug which caused difficulty with listing and setting
6640 breakpoints in include files which contain C code. (In the past, you had to
6641 try twice in order to list an include file that you hadn't looked at before.)
6643 * Interesting infernals change
6645 GDB now deals with arbitrary numbers of sections, where the symbols for each
6646 section must be relocated relative to that section's landing place in the
6647 target's address space. This work was needed to support ELF with embedded
6648 stabs used by Solaris-2.0.
6650 * Bug fixes (of course!)
6652 There have been loads of fixes for the following things:
6653 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6654 i960, stabs, DOS(GO32), procfs, etc...
6656 See the ChangeLog for details.
6658 *** Changes in GDB-4.5:
6660 * New machines supported (host and target)
6662 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6664 SGI Irix-4.x mips-sgi-irix4 or iris4
6666 * New malloc package
6668 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6669 Mmalloc is capable of handling mutiple heaps of memory. It is also
6670 capable of saving a heap to a file, and then mapping it back in later.
6671 This can be used to greatly speedup the startup of GDB by using a
6672 pre-parsed symbol table which lives in a mmalloc managed heap. For
6673 more details, please read mmalloc/mmalloc.texi.
6677 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6678 'help info proc' for details.
6680 * MIPS ecoff symbol table format
6682 The code that reads MIPS symbol table format is now supported on all hosts.
6683 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6686 * File name changes for MS-DOS
6688 Many files in the config directories have been renamed to make it easier to
6689 support GDB on MS-DOSe systems (which have very restrictive file name
6690 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6691 environment) is close to working but has some remaining problems. Note
6692 that debugging of DOS programs is not supported, due to limitations
6693 in the ``operating system'', but it can be used to host cross-debugging.
6695 * Cross byte order fixes
6697 Many fixes have been made to support cross debugging of Sparc and MIPS
6698 targets from hosts whose byte order differs.
6700 * New -mapped and -readnow options
6702 If memory-mapped files are available on your system through the 'mmap'
6703 system call, you can use the -mapped option on the `file' or
6704 `symbol-file' commands to cause GDB to write the symbols from your
6705 program into a reusable file. If the program you are debugging is
6706 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6707 Future GDB debugging sessions will notice the presence of this file,
6708 and will quickly map in symbol information from it, rather than reading
6709 the symbol table from the executable program. Using the '-mapped'
6710 option in a GDB `file' or `symbol-file' command has the same effect as
6711 starting GDB with the '-mapped' command-line option.
6713 You can cause GDB to read the entire symbol table immediately by using
6714 the '-readnow' option with any of the commands that load symbol table
6715 information (or on the GDB command line). This makes the command
6716 slower, but makes future operations faster.
6718 The -mapped and -readnow options are typically combined in order to
6719 build a `fred.syms' file that contains complete symbol information.
6720 A simple GDB invocation to do nothing but build a `.syms' file for future
6723 gdb -batch -nx -mapped -readnow programname
6725 The `.syms' file is specific to the host machine on which GDB is run.
6726 It holds an exact image of GDB's internal symbol table. It cannot be
6727 shared across multiple host platforms.
6729 * longjmp() handling
6731 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6732 siglongjmp() without losing control. This feature has not yet been ported to
6733 all systems. It currently works on many 386 platforms, all MIPS-based
6734 platforms (SGI, DECstation, etc), and Sun3/4.
6738 Preliminary work has been put in to support the new Solaris OS from Sun. At
6739 this time, it can control and debug processes, but it is not capable of
6744 As always, many many bug fixes. The major areas were with g++, and mipsread.
6745 People using the MIPS-based platforms should experience fewer mysterious
6746 crashes and trashed symbol tables.
6748 *** Changes in GDB-4.4:
6750 * New machines supported (host and target)
6752 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6754 BSD Reno on Vax vax-dec-bsd
6755 Ultrix on Vax vax-dec-ultrix
6757 * New machines supported (target)
6759 AMD 29000 embedded, using EBMON a29k-none-none
6763 GDB continues to improve its handling of C++. `References' work better.
6764 The demangler has also been improved, and now deals with symbols mangled as
6765 per the Annotated C++ Reference Guide.
6767 GDB also now handles `stabs' symbol information embedded in MIPS
6768 `ecoff' symbol tables. Since the ecoff format was not easily
6769 extensible to handle new languages such as C++, this appeared to be a
6770 good way to put C++ debugging info into MIPS binaries. This option
6771 will be supported in the GNU C compiler, version 2, when it is
6774 * New features for SVR4
6776 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6777 shared libraries. Debugging dynamically linked programs should present
6778 only minor differences from debugging statically linked programs.
6780 The `info proc' command will print out information about any process
6781 on an SVR4 system (including the one you are debugging). At the moment,
6782 it prints the address mappings of the process.
6784 If you bring up GDB on another SVR4 system, please send mail to
6785 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6787 * Better dynamic linking support in SunOS
6789 Reading symbols from shared libraries which contain debugging symbols
6790 now works properly. However, there remain issues such as automatic
6791 skipping of `transfer vector' code during function calls, which
6792 make it harder to debug code in a shared library, than to debug the
6793 same code linked statically.
6797 GDB is now using the latest `getopt' routines from the FSF. This
6798 version accepts the -- prefix for options with long names. GDB will
6799 continue to accept the old forms (-option and +option) as well.
6800 Various single letter abbreviations for options have been explicity
6801 added to the option table so that they won't get overshadowed in the
6802 future by other options that begin with the same letter.
6806 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6807 Many assorted bugs have been handled. Many more remain to be handled.
6808 See the various ChangeLog files (primarily in gdb and bfd) for details.
6811 *** Changes in GDB-4.3:
6813 * New machines supported (host and target)
6815 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6816 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6817 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6819 * Almost SCO Unix support
6821 We had hoped to support:
6822 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6823 (except for core file support), but we discovered very late in the release
6824 that it has problems with process groups that render gdb unusable. Sorry
6825 about that. I encourage people to fix it and post the fixes.
6827 * Preliminary ELF and DWARF support
6829 GDB can read ELF object files on System V Release 4, and can handle
6830 debugging records for C, in DWARF format, in ELF files. This support
6831 is preliminary. If you bring up GDB on another SVR4 system, please
6832 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6837 GDB now uses the latest `readline' library. One user-visible change
6838 is that two tabs will list possible command completions, which previously
6839 required typing M-? (meta-question mark, or ESC ?).
6843 The `stepi' bug that many of you noticed has been squashed.
6844 Many bugs in C++ have been handled. Many more remain to be handled.
6845 See the various ChangeLog files (primarily in gdb and bfd) for details.
6847 * State of the MIPS world (in case you wondered):
6849 GDB can understand the symbol tables emitted by the compilers
6850 supplied by most vendors of MIPS-based machines, including DEC. These
6851 symbol tables are in a format that essentially nobody else uses.
6853 Some versions of gcc come with an assembler post-processor called
6854 mips-tfile. This program is required if you want to do source-level
6855 debugging of gcc-compiled programs. I believe FSF does not ship
6856 mips-tfile with gcc version 1, but it will eventually come with gcc
6859 Debugging of g++ output remains a problem. g++ version 1.xx does not
6860 really support it at all. (If you're lucky, you should be able to get
6861 line numbers and stack traces to work, but no parameters or local
6862 variables.) With some work it should be possible to improve the
6865 When gcc version 2 is released, you will have somewhat better luck.
6866 However, even then you will get confusing results for inheritance and
6869 We will eventually provide full debugging of g++ output on
6870 DECstations. This will probably involve some kind of stabs-in-ecoff
6871 encapulation, but the details have not been worked out yet.
6874 *** Changes in GDB-4.2:
6876 * Improved configuration
6878 Only one copy of `configure' exists now, and it is not self-modifying.
6879 Porting BFD is simpler.
6883 The `step' and `next' commands now only stop at the first instruction
6884 of a source line. This prevents the multiple stops that used to occur
6885 in switch statements, for-loops, etc. `Step' continues to stop if a
6886 function that has debugging information is called within the line.
6890 Lots of small bugs fixed. More remain.
6892 * New host supported (not target)
6894 Intel 386 PC clone running Mach i386-none-mach
6897 *** Changes in GDB-4.1:
6899 * Multiple source language support
6901 GDB now has internal scaffolding to handle several source languages.
6902 It determines the type of each source file from its filename extension,
6903 and will switch expression parsing and number formatting to match the
6904 language of the function in the currently selected stack frame.
6905 You can also specifically set the language to be used, with
6906 `set language c' or `set language modula-2'.
6910 GDB now has preliminary support for the GNU Modula-2 compiler,
6911 currently under development at the State University of New York at
6912 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6913 continue through the fall of 1991 and into 1992.
6915 Other Modula-2 compilers are currently not supported, and attempting to
6916 debug programs compiled with them will likely result in an error as the
6917 symbol table is read. Feel free to work on it, though!
6919 There are hooks in GDB for strict type checking and range checking,
6920 in the `Modula-2 philosophy', but they do not currently work.
6924 GDB can now write to executable and core files (e.g. patch
6925 a variable's value). You must turn this switch on, specify
6926 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6927 by assigning a new value to a variable. Modifications take
6930 * Automatic SunOS shared library reading
6932 When you run your program, GDB automatically determines where its
6933 shared libraries (if any) have been loaded, and reads their symbols.
6934 The `share' command is no longer needed. This also works when
6935 examining core files.
6939 You can specify the number of lines that the `list' command shows.
6942 * New machines supported (host and target)
6944 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6945 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6946 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6948 * New hosts supported (not targets)
6950 IBM RT/PC: romp-ibm-aix or rtpc
6952 * New targets supported (not hosts)
6954 AMD 29000 embedded with COFF a29k-none-coff
6955 AMD 29000 embedded with a.out a29k-none-aout
6956 Ultracomputer remote kernel debug a29k-nyu-kern
6958 * New remote interfaces
6964 *** Changes in GDB-4.0:
6968 Wide output is wrapped at good places to make the output more readable.
6970 Gdb now supports cross-debugging from a host machine of one type to a
6971 target machine of another type. Communication with the target system
6972 is over serial lines. The ``target'' command handles connecting to the
6973 remote system; the ``load'' command will download a program into the
6974 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6975 also supports debugging of realtime processes running under VxWorks,
6976 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6977 stub on the target system.
6979 New CPUs supported include the AMD 29000 and Intel 960.
6981 GDB now reads object files and symbol tables via a ``binary file''
6982 library, which allows a single copy of GDB to debug programs of multiple
6983 object file types such as a.out and coff.
6985 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6986 refcard.dvi and refcard.ps are available to format it).
6989 * Control-Variable user interface simplified
6991 All variables that control the operation of the debugger can be set
6992 by the ``set'' command, and displayed by the ``show'' command.
6994 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6995 ``Show prompt'' produces the response:
6996 Gdb's prompt is new-gdb=>.
6998 What follows are the NEW set commands. The command ``help set'' will
6999 print a complete list of old and new set commands. ``help set FOO''
7000 will give a longer description of the variable FOO. ``show'' will show
7001 all of the variable descriptions and their current settings.
7003 confirm on/off: Enables warning questions for operations that are
7004 hard to recover from, e.g. rerunning the program while
7005 it is already running. Default is ON.
7007 editing on/off: Enables EMACS style command line editing
7008 of input. Previous lines can be recalled with
7009 control-P, the current line can be edited with control-B,
7010 you can search for commands with control-R, etc.
7013 history filename NAME: NAME is where the gdb command history
7014 will be stored. The default is .gdb_history,
7015 or the value of the environment variable
7018 history size N: The size, in commands, of the command history. The
7019 default is 256, or the value of the environment variable
7022 history save on/off: If this value is set to ON, the history file will
7023 be saved after exiting gdb. If set to OFF, the
7024 file will not be saved. The default is OFF.
7026 history expansion on/off: If this value is set to ON, then csh-like
7027 history expansion will be performed on
7028 command line input. The default is OFF.
7030 radix N: Sets the default radix for input and output. It can be set
7031 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7032 in the current radix, so "set radix 10" is always a no-op.
7034 height N: This integer value is the number of lines on a page. Default
7035 is 24, the current `stty rows'' setting, or the ``li#''
7036 setting from the termcap entry matching the environment
7039 width N: This integer value is the number of characters on a line.
7040 Default is 80, the current `stty cols'' setting, or the ``co#''
7041 setting from the termcap entry matching the environment
7044 Note: ``set screensize'' is obsolete. Use ``set height'' and
7045 ``set width'' instead.
7047 print address on/off: Print memory addresses in various command displays,
7048 such as stack traces and structure values. Gdb looks
7049 more ``symbolic'' if you turn this off; it looks more
7050 ``machine level'' with it on. Default is ON.
7052 print array on/off: Prettyprint arrays. New convenient format! Default
7055 print demangle on/off: Print C++ symbols in "source" form if on,
7058 print asm-demangle on/off: Same, for assembler level printouts
7061 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7064 * Support for Epoch Environment.
7066 The epoch environment is a version of Emacs v18 with windowing. One
7067 new command, ``inspect'', is identical to ``print'', except that if you
7068 are running in the epoch environment, the value is printed in its own
7072 * Support for Shared Libraries
7074 GDB can now debug programs and core files that use SunOS shared libraries.
7075 Symbols from a shared library cannot be referenced
7076 before the shared library has been linked with the program (this
7077 happens after you type ``run'' and before the function main() is entered).
7078 At any time after this linking (including when examining core files
7079 from dynamically linked programs), gdb reads the symbols from each
7080 shared library when you type the ``sharedlibrary'' command.
7081 It can be abbreviated ``share''.
7083 sharedlibrary REGEXP: Load shared object library symbols for files
7084 matching a unix regular expression. No argument
7085 indicates to load symbols for all shared libraries.
7087 info sharedlibrary: Status of loaded shared libraries.
7092 A watchpoint stops execution of a program whenever the value of an
7093 expression changes. Checking for this slows down execution
7094 tremendously whenever you are in the scope of the expression, but is
7095 quite useful for catching tough ``bit-spreader'' or pointer misuse
7096 problems. Some machines such as the 386 have hardware for doing this
7097 more quickly, and future versions of gdb will use this hardware.
7099 watch EXP: Set a watchpoint (breakpoint) for an expression.
7101 info watchpoints: Information about your watchpoints.
7103 delete N: Deletes watchpoint number N (same as breakpoints).
7104 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7105 enable N: Re-enables watchpoint number N (same as breakpoints).
7108 * C++ multiple inheritance
7110 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7113 * C++ exception handling
7115 Gdb now supports limited C++ exception handling. Besides the existing
7116 ability to breakpoint on an exception handler, gdb can breakpoint on
7117 the raising of an exception (before the stack is peeled back to the
7120 catch FOO: If there is a FOO exception handler in the dynamic scope,
7121 set a breakpoint to catch exceptions which may be raised there.
7122 Multiple exceptions (``catch foo bar baz'') may be caught.
7124 info catch: Lists all exceptions which may be caught in the
7125 current stack frame.
7128 * Minor command changes
7130 The command ``call func (arg, arg, ...)'' now acts like the print
7131 command, except it does not print or save a value if the function's result
7132 is void. This is similar to dbx usage.
7134 The ``up'' and ``down'' commands now always print the frame they end up
7135 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7136 frames without printing.
7138 * New directory command
7140 'dir' now adds directories to the FRONT of the source search path.
7141 The path starts off empty. Source files that contain debug information
7142 about the directory in which they were compiled can be found even
7143 with an empty path; Sun CC and GCC include this information. If GDB can't
7144 find your source file in the current directory, type "dir .".
7146 * Configuring GDB for compilation
7148 For normal use, type ``./configure host''. See README or gdb.texinfo
7151 GDB now handles cross debugging. If you are remotely debugging between
7152 two different machines, type ``./configure host -target=targ''.
7153 Host is the machine where GDB will run; targ is the machine
7154 where the program that you are debugging will run.