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 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
93 of objfiles associated to that program space.
95 *** Changes in GDB 8.2
97 * The 'set disassembler-options' command now supports specifying options
100 * The 'symbol-file' command now accepts an '-o' option to add a relative
101 offset to all sections.
103 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
104 a relative offset to all sections, but it allows to override the load
105 address of individual sections using '-s'.
107 * The 'add-symbol-file' command no longer requires the second argument
108 (address of the text section).
110 * The endianness used with the 'set endian auto' mode in the absence of
111 an executable selected for debugging is now the last endianness chosen
112 either by one of the 'set endian big' and 'set endian little' commands
113 or by inferring from the last executable used, rather than the startup
116 * The pager now allows a "c" response, meaning to disable the pager
117 for the rest of the current command.
119 * The commands 'info variables/functions/types' now show the source line
120 numbers of symbol definitions when available.
122 * 'info proc' now works on running processes on FreeBSD systems and core
123 files created on FreeBSD systems.
125 * C expressions can now use _Alignof, and C++ expressions can now use
128 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
129 the vector length while the process is running.
135 Control display of debugging info regarding the FreeBSD native target.
137 set|show varsize-limit
138 This new setting allows the user to control the maximum size of Ada
139 objects being printed when those objects have a variable type,
140 instead of that maximum size being hardcoded to 65536 bytes.
142 set|show record btrace cpu
143 Controls the processor to be used for enabling errata workarounds for
146 maint check libthread-db
147 Run integrity checks on the current inferior's thread debugging
150 maint set check-libthread-db (on|off)
151 maint show check-libthread-db
152 Control whether to run integrity checks on inferior specific thread
153 debugging libraries as they are loaded. The default is not to
158 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
160 ** The commands attached to a breakpoint can be set by assigning to
161 the breakpoint's "commands" field.
163 ** gdb.execute can now execute multi-line gdb commands.
165 ** The new functions gdb.convenience_variable and
166 gdb.set_convenience_variable can be used to get and set the value
167 of convenience variables.
169 ** A gdb.Parameter will no longer print the "set" help text on an
170 ordinary "set"; instead by default a "set" will be silent unless
171 the get_set_string method returns a non-empty string.
175 RiscV ELF riscv*-*-elf
177 * Removed targets and native configurations
179 m88k running OpenBSD m88*-*-openbsd*
180 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
181 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
182 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
184 * Aarch64/Linux hardware watchpoints improvements
186 Hardware watchpoints on unaligned addresses are now properly
187 supported when running Linux kernel 4.10 or higher: read and access
188 watchpoints are no longer spuriously missed, and all watchpoints
189 lengths between 1 and 8 bytes are supported. On older kernels,
190 watchpoints set on unaligned addresses are no longer missed, with
191 the tradeoff that there is a possibility of false hits being
196 --enable-codesign=CERT
197 This can be used to invoke "codesign -s CERT" after building gdb.
198 This option is useful on macOS, where code signing is required for
199 gdb to work properly.
201 --disable-gdbcli has been removed
202 This is now silently accepted, but does nothing.
204 *** Changes in GDB 8.1
206 * GDB now supports dynamically creating arbitrary register groups specified
207 in XML target descriptions. This allows for finer grain grouping of
208 registers on systems with a large amount of registers.
210 * The 'ptype' command now accepts a '/o' flag, which prints the
211 offsets and sizes of fields in a struct, like the pahole(1) tool.
213 * New "--readnever" command line option instructs GDB to not read each
214 symbol file's symbolic debug information. This makes startup faster
215 but at the expense of not being able to perform symbolic debugging.
216 This option is intended for use cases where symbolic debugging will
217 not be used, e.g., when you only need to dump the debuggee's core.
219 * GDB now uses the GNU MPFR library, if available, to emulate target
220 floating-point arithmetic during expression evaluation when the target
221 uses different floating-point formats than the host. At least version
222 3.1 of GNU MPFR is required.
224 * GDB now supports access to the guarded-storage-control registers and the
225 software-based guarded-storage broadcast control registers on IBM z14.
227 * On Unix systems, GDB now supports transmitting environment variables
228 that are to be set or unset to GDBserver. These variables will
229 affect the environment to be passed to the remote inferior.
231 To inform GDB of environment variables that are to be transmitted to
232 GDBserver, use the "set environment" command. Only user set
233 environment variables are sent to GDBserver.
235 To inform GDB of environment variables that are to be unset before
236 the remote inferior is started by the GDBserver, use the "unset
237 environment" command.
239 * Completion improvements
241 ** GDB can now complete function parameters in linespecs and
242 explicit locations without quoting. When setting breakpoints,
243 quoting around functions names to help with TAB-completion is
244 generally no longer necessary. For example, this now completes
247 (gdb) b function(in[TAB]
248 (gdb) b function(int)
250 Related, GDB is no longer confused with completing functions in
251 C++ anonymous namespaces:
254 (gdb) b (anonymous namespace)::[TAB][TAB]
255 (anonymous namespace)::a_function()
256 (anonymous namespace)::b_function()
258 ** GDB now has much improved linespec and explicit locations TAB
259 completion support, that better understands what you're
260 completing and offers better suggestions. For example, GDB no
261 longer offers data symbols as possible completions when you're
262 setting a breakpoint.
264 ** GDB now TAB-completes label symbol names.
266 ** The "complete" command now mimics TAB completion accurately.
268 * New command line options (gcore)
271 Dump all memory mappings.
273 * Breakpoints on C++ functions are now set on all scopes by default
275 By default, breakpoints on functions/methods are now interpreted as
276 specifying all functions with the given name ignoring missing
277 leading scopes (namespaces and classes).
279 For example, assuming a C++ program with symbols named:
284 both commands "break func()" and "break B::func()" set a breakpoint
287 You can use the new flag "-qualified" to override this. This makes
288 GDB interpret the specified function name as a complete
289 fully-qualified name instead. For example, using the same C++
290 program, the "break -q B::func" command sets a breakpoint on
291 "B::func", only. A parameter has been added to the Python
292 gdb.Breakpoint constructor to achieve the same result when creating
293 a breakpoint from Python.
295 * Breakpoints on functions marked with C++ ABI tags
297 GDB can now set breakpoints on functions marked with C++ ABI tags
298 (e.g., [abi:cxx11]). See here for a description of ABI tags:
299 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
301 Functions with a C++11 abi tag are demangled/displayed like this:
303 function[abi:cxx11](int)
306 You can now set a breakpoint on such functions simply as if they had
309 (gdb) b function(int)
311 Or if you need to disambiguate between tags, like:
313 (gdb) b function[abi:other_tag](int)
315 Tab completion was adjusted accordingly as well.
319 ** New events gdb.new_inferior, gdb.inferior_deleted, and
320 gdb.new_thread are emitted. See the manual for further
321 description of these.
323 ** A new function, "gdb.rbreak" has been added to the Python API.
324 This function allows the setting of a large number of breakpoints
325 via a regex pattern in Python. See the manual for further details.
327 ** Python breakpoints can now accept explicit locations. See the
328 manual for a further description of this feature.
331 * New features in the GDB remote stub, GDBserver
333 ** GDBserver is now able to start inferior processes with a
334 specified initial working directory.
336 The user can set the desired working directory to be used from
337 GDB using the new "set cwd" command.
339 ** New "--selftest" command line option runs some GDBserver self
340 tests. These self tests are disabled in releases.
342 ** On Unix systems, GDBserver now does globbing expansion and variable
343 substitution in inferior command line arguments.
345 This is done by starting inferiors using a shell, like GDB does.
346 See "set startup-with-shell" in the user manual for how to disable
347 this from GDB when using "target extended-remote". When using
348 "target remote", you can disable the startup with shell by using the
349 new "--no-startup-with-shell" GDBserver command line option.
351 ** On Unix systems, GDBserver now supports receiving environment
352 variables that are to be set or unset from GDB. These variables
353 will affect the environment to be passed to the inferior.
355 * When catching an Ada exception raised with a message, GDB now prints
356 the message in the catchpoint hit notification. In GDB/MI mode, that
357 information is provided as an extra field named "exception-message"
358 in the *stopped notification.
360 * Trait objects can now be inspected When debugging Rust code. This
361 requires compiler support which will appear in Rust 1.24.
365 QEnvironmentHexEncoded
366 Inform GDBserver of an environment variable that is to be passed to
367 the inferior when starting it.
370 Inform GDBserver of an environment variable that is to be unset
371 before starting the remote inferior.
374 Inform GDBserver that the environment should be reset (i.e.,
375 user-set environment variables should be unset).
378 Indicates whether the inferior must be started with a shell or not.
381 Tell GDBserver that the inferior to be started should use a specific
384 * The "maintenance print c-tdesc" command now takes an optional
385 argument which is the file name of XML target description.
387 * The "maintenance selftest" command now takes an optional argument to
388 filter the tests to be run.
390 * The "enable", and "disable" commands now accept a range of
391 breakpoint locations, e.g. "enable 1.3-5".
396 Set and show the current working directory for the inferior.
399 Set and show compilation command used for compiling and injecting code
400 with the 'compile' commands.
402 set debug separate-debug-file
403 show debug separate-debug-file
404 Control the display of debug output about separate debug file search.
406 set dump-excluded-mappings
407 show dump-excluded-mappings
408 Control whether mappings marked with the VM_DONTDUMP flag should be
409 dumped when generating a core file.
412 List the registered selftests.
415 Start the debugged program stopping at the first instruction.
418 Control display of debugging messages related to OpenRISC targets.
420 set|show print type nested-type-limit
421 Set and show the limit of nesting level for nested types that the
422 type printer will show.
424 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
427 * Safer/improved support for debugging with no debug info
429 GDB no longer assumes functions with no debug information return
432 This means that GDB now refuses to call such functions unless you
433 tell it the function's type, by either casting the call to the
434 declared return type, or by casting the function to a function
435 pointer of the right type, and calling that:
437 (gdb) p getenv ("PATH")
438 'getenv' has unknown return type; cast the call to its declared return type
439 (gdb) p (char *) getenv ("PATH")
440 $1 = 0x7fffffffe "/usr/local/bin:/"...
441 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
442 $2 = 0x7fffffffe "/usr/local/bin:/"...
444 Similarly, GDB no longer assumes that global variables with no debug
445 info have type 'int', and refuses to print the variable's value
446 unless you tell it the variable's type:
449 'var' has unknown type; cast it to its declared type
453 * New native configurations
455 FreeBSD/aarch64 aarch64*-*-freebsd*
456 FreeBSD/arm arm*-*-freebsd*
460 FreeBSD/aarch64 aarch64*-*-freebsd*
461 FreeBSD/arm arm*-*-freebsd*
462 OpenRISC ELF or1k*-*-elf
464 * Removed targets and native configurations
466 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
468 *** Changes in GDB 8.0
470 * GDB now supports access to the PKU register on GNU/Linux. The register is
471 added by the Memory Protection Keys for Userspace feature which will be
472 available in future Intel CPUs.
474 * GDB now supports C++11 rvalue references.
478 ** New functions to start, stop and access a running btrace recording.
479 ** Rvalue references are now supported in gdb.Type.
481 * GDB now supports recording and replaying rdrand and rdseed Intel 64
484 * Building GDB and GDBserver now requires a C++11 compiler.
486 For example, GCC 4.8 or later.
488 It is no longer possible to build GDB or GDBserver with a C
489 compiler. The --disable-build-with-cxx configure option has been
492 * Building GDB and GDBserver now requires GNU make >= 3.81.
494 It is no longer supported to build GDB or GDBserver with another
495 implementation of the make program or an earlier version of GNU make.
497 * Native debugging on MS-Windows supports command-line redirection
499 Command-line arguments used for starting programs on MS-Windows can
500 now include redirection symbols supported by native Windows shells,
501 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
502 as "run", "start", and "set args", as well as the corresponding MI
505 * Support for thread names on MS-Windows.
507 GDB now catches and handles the special exception that programs
508 running on MS-Windows use to assign names to threads in the
511 * Support for Java programs compiled with gcj has been removed.
513 * User commands now accept an unlimited number of arguments.
514 Previously, only up to 10 was accepted.
516 * The "eval" command now expands user-defined command arguments.
518 This makes it easier to process a variable number of arguments:
523 eval "print $arg%d", $i
528 * Target descriptions can now describe registers for sparc32 and sparc64.
530 * GDB now supports DWARF version 5 (debug information format).
531 Its .debug_names index is not yet supported.
533 * New native configurations
535 FreeBSD/mips mips*-*-freebsd
539 Synopsys ARC arc*-*-elf32
540 FreeBSD/mips mips*-*-freebsd
542 * Removed targets and native configurations
544 Alpha running FreeBSD alpha*-*-freebsd*
545 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
550 Erases all the flash memory regions reported by the target.
552 maint print arc arc-instruction address
553 Print internal disassembler information about instruction at a given address.
557 set disassembler-options
558 show disassembler-options
559 Controls the passing of target specific information to the disassembler.
560 If it is necessary to specify more than one disassembler option then
561 multiple options can be placed together into a comma separated list.
562 The default value is the empty string. Currently, the only supported
563 targets are ARM, PowerPC and S/390.
568 Erases all the flash memory regions reported by the target. This is
569 equivalent to the CLI command flash-erase.
571 -file-list-shared-libraries
572 List the shared libraries in the program. This is
573 equivalent to the CLI command "info shared".
576 Catchpoints stopping the program when Ada exceptions are
577 handled. This is equivalent to the CLI command "catch handlers".
579 *** Changes in GDB 7.12
581 * GDB and GDBserver now build with a C++ compiler by default.
583 The --enable-build-with-cxx configure option is now enabled by
584 default. One must now explicitly configure with
585 --disable-build-with-cxx in order to build with a C compiler. This
586 option will be removed in a future release.
588 * GDBserver now supports recording btrace without maintaining an active
591 * GDB now supports a negative repeat count in the 'x' command to examine
592 memory backward from the given address. For example:
595 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
596 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
597 (gdb) x/-5i 0x0000000000400580
598 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
599 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
600 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
601 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
602 0x40057b <main(int, char**)+25>:
603 callq 0x400536 <Func1(int, char const*)>
605 * Fortran: Support structures with fields of dynamic types and
606 arrays of dynamic types.
608 * The symbol dumping maintenance commands have new syntax.
609 maint print symbols [-pc address] [--] [filename]
610 maint print symbols [-objfile objfile] [-source source] [--] [filename]
611 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
612 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
613 maint print msymbols [-objfile objfile] [--] [filename]
615 * GDB now supports multibit bitfields and enums in target register
618 * New Python-based convenience function $_as_string(val), which returns
619 the textual representation of a value. This function is especially
620 useful to obtain the text label of an enum value.
622 * Intel MPX bound violation handling.
624 Segmentation faults caused by a Intel MPX boundary violation
625 now display the kind of violation (upper or lower), the memory
626 address accessed and the memory bounds, along with the usual
627 signal received and code location.
631 Program received signal SIGSEGV, Segmentation fault
632 Upper bound violation while accessing address 0x7fffffffc3b3
633 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
634 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
636 * Rust language support.
637 GDB now supports debugging programs written in the Rust programming
638 language. See https://www.rust-lang.org/ for more information about
641 * Support for running interpreters on specified input/output devices
643 GDB now supports a new mechanism that allows frontends to provide
644 fully featured GDB console views, as a better alternative to
645 building such views on top of the "-interpreter-exec console"
646 command. See the new "new-ui" command below. With that command,
647 frontends can now start GDB in the traditional command-line mode
648 running in an embedded terminal emulator widget, and create a
649 separate MI interpreter running on a specified i/o device. In this
650 way, GDB handles line editing, history, tab completion, etc. in the
651 console all by itself, and the GUI uses the separate MI interpreter
652 for its own control and synchronization, invisible to the command
655 * The "catch syscall" command catches groups of related syscalls.
657 The "catch syscall" command now supports catching a group of related
658 syscalls using the 'group:' or 'g:' prefix.
663 skip -gfile file-glob-pattern
664 skip -function function
665 skip -rfunction regular-expression
666 A generalized form of the skip command, with new support for
667 glob-style file names and regular expressions for function names.
668 Additionally, a file spec and a function spec may now be combined.
670 maint info line-table REGEXP
671 Display the contents of GDB's internal line table data struture.
674 Run any GDB unit tests that were compiled in.
677 Start a new user interface instance running INTERP as interpreter,
678 using the TTY file for input/output.
682 ** gdb.Breakpoint objects have a new attribute "pending", which
683 indicates whether the breakpoint is pending.
684 ** Three new breakpoint-related events have been added:
685 gdb.breakpoint_created, gdb.breakpoint_modified, and
686 gdb.breakpoint_deleted.
689 Signal ("set") the given MS-Windows event object. This is used in
690 conjunction with the Windows JIT debugging (AeDebug) support, where
691 the OS suspends a crashing process until a debugger can attach to
692 it. Resuming the crashing process, in order to debug it, is done by
695 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
696 was added in GDBserver, including JIT compiling fast tracepoint's
697 conditional expression bytecode into native code.
699 * Support for various remote target protocols and ROM monitors has
702 target m32rsdi Remote M32R debugging over SDI
703 target mips MIPS remote debugging protocol
704 target pmon PMON ROM monitor
705 target ddb NEC's DDB variant of PMON for Vr4300
706 target rockhopper NEC RockHopper variant of PMON
707 target lsi LSI variant of PMO
709 * Support for tracepoints and fast tracepoints on powerpc-linux,
710 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
711 including JIT compiling fast tracepoint's conditional expression
712 bytecode into native code.
714 * MI async record =record-started now includes the method and format used for
715 recording. For example:
717 =record-started,thread-group="i1",method="btrace",format="bts"
719 * MI async record =thread-selected now includes the frame field. For example:
721 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
725 Andes NDS32 nds32*-*-elf
727 *** Changes in GDB 7.11
729 * GDB now supports debugging kernel-based threads on FreeBSD.
731 * Per-inferior thread numbers
733 Thread numbers are now per inferior instead of global. If you're
734 debugging multiple inferiors, GDB displays thread IDs using a
735 qualified INF_NUM.THR_NUM form. For example:
739 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
740 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
741 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
742 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
744 As consequence, thread numbers as visible in the $_thread
745 convenience variable and in Python's InferiorThread.num attribute
746 are no longer unique between inferiors.
748 GDB now maintains a second thread ID per thread, referred to as the
749 global thread ID, which is the new equivalent of thread numbers in
750 previous releases. See also $_gthread below.
752 For backwards compatibility, MI's thread IDs always refer to global
755 * Commands that accept thread IDs now accept the qualified
756 INF_NUM.THR_NUM form as well. For example:
759 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
762 * In commands that accept a list of thread IDs, you can now refer to
763 all threads of an inferior using a star wildcard. GDB accepts
764 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
765 refer to all threads of the current inferior. For example, "info
768 * You can use "info threads -gid" to display the global thread ID of
771 * The new convenience variable $_gthread holds the global number of
774 * The new convenience variable $_inferior holds the number of the
777 * GDB now displays the ID and name of the thread that hit a breakpoint
778 or received a signal, if your program is multi-threaded. For
781 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
782 Thread 1 "main" received signal SIGINT, Interrupt.
784 * Record btrace now supports non-stop mode.
786 * Support for tracepoints on aarch64-linux was added in GDBserver.
788 * The 'record instruction-history' command now indicates speculative execution
789 when using the Intel Processor Trace recording format.
791 * GDB now allows users to specify explicit locations, bypassing
792 the linespec parser. This feature is also available to GDB/MI
795 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
796 GDB now is able to debug both AArch64 applications and ARM applications
799 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
800 including JIT compiling fast tracepoint's conditional expression bytecode
803 * GDB now supports displaced stepping on AArch64 GNU/Linux.
805 * "info threads", "info inferiors", "info display", "info checkpoints"
806 and "maint info program-spaces" now list the corresponding items in
807 ascending ID order, for consistency with all other "info" commands.
809 * In Ada, the overloads selection menu has been enhanced to display the
810 parameter types and the return types for the matching overloaded subprograms.
814 maint set target-non-stop (on|off|auto)
815 maint show target-non-stop
816 Control whether GDB targets always operate in non-stop mode even if
817 "set non-stop" is "off". The default is "auto", meaning non-stop
818 mode is enabled if supported by the target.
820 maint set bfd-sharing
821 maint show bfd-sharing
822 Control the reuse of bfd objects.
826 Control display of debugging info regarding bfd caching.
830 Control display of debugging info regarding FreeBSD threads.
832 set remote multiprocess-extensions-packet
833 show remote multiprocess-extensions-packet
834 Set/show the use of the remote protocol multiprocess extensions.
836 set remote thread-events
837 show remote thread-events
838 Set/show the use of thread create/exit events.
840 set ada print-signatures on|off
841 show ada print-signatures"
842 Control whether parameter types and return types are displayed in overloads
843 selection menus. It is activaled (@code{on}) by default.
847 Controls the maximum size of memory, in bytes, that GDB will
848 allocate for value contents. Prevents incorrect programs from
849 causing GDB to allocate overly large buffers. Default is 64k.
851 * The "disassemble" command accepts a new modifier: /s.
852 It prints mixed source+disassembly like /m with two differences:
853 - disassembled instructions are now printed in program order, and
854 - and source for all relevant files is now printed.
855 The "/m" option is now considered deprecated: its "source-centric"
856 output hasn't proved useful in practice.
858 * The "record instruction-history" command accepts a new modifier: /s.
859 It behaves exactly like /m and prints mixed source+disassembly.
861 * The "set scheduler-locking" command supports a new mode "replay".
862 It behaves like "off" in record mode and like "on" in replay mode.
864 * Support for various ROM monitors has been removed:
866 target dbug dBUG ROM monitor for Motorola ColdFire
867 target picobug Motorola picobug monitor
868 target dink32 DINK32 ROM monitor for PowerPC
869 target m32r Renesas M32R/D ROM monitor
870 target mon2000 mon2000 ROM monitor
871 target ppcbug PPCBUG ROM monitor for PowerPC
873 * Support for reading/writing memory and extracting values on architectures
874 whose memory is addressable in units of any integral multiple of 8 bits.
877 Allows to break when an Ada exception is handled.
882 Indicates that an exec system call was executed.
884 exec-events feature in qSupported
885 The qSupported packet allows GDB to request support for exec
886 events using the new 'gdbfeature' exec-event, and the qSupported
887 response can contain the corresponding 'stubfeature'. Set and
888 show commands can be used to display whether these features are enabled.
891 Equivalent to interrupting with the ^C character, but works in
894 thread created stop reason (T05 create:...)
895 Indicates that the thread was just created and is stopped at entry.
897 thread exit stop reply (w exitcode;tid)
898 Indicates that the thread has terminated.
901 Enables/disables thread create and exit event reporting. For
902 example, this is used in non-stop mode when GDB stops a set of
903 threads and synchronously waits for the their corresponding stop
904 replies. Without exit events, if one of the threads exits, GDB
905 would hang forever not knowing that it should no longer expect a
906 stop for that same thread.
909 Indicates that there are no resumed threads left in the target (all
910 threads are stopped). The remote stub reports support for this stop
911 reply to GDB's qSupported query.
914 Enables/disables catching syscalls from the inferior process.
915 The remote stub reports support for this packet to GDB's qSupported query.
917 syscall_entry stop reason
918 Indicates that a syscall was just called.
920 syscall_return stop reason
921 Indicates that a syscall just returned.
923 * Extended-remote exec events
925 ** GDB now has support for exec events on extended-remote Linux targets.
926 For such targets with Linux kernels 2.5.46 and later, this enables
927 follow-exec-mode and exec catchpoints.
929 set remote exec-event-feature-packet
930 show remote exec-event-feature-packet
931 Set/show the use of the remote exec event feature.
933 * Thread names in remote protocol
935 The reply to qXfer:threads:read may now include a name attribute for each
938 * Target remote mode fork and exec events
940 ** GDB now has support for fork and exec events on target remote mode
941 Linux targets. For such targets with Linux kernels 2.5.46 and later,
942 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
943 fork and exec catchpoints.
945 * Remote syscall events
947 ** GDB now has support for catch syscall on remote Linux targets,
948 currently enabled on x86/x86_64 architectures.
950 set remote catch-syscall-packet
951 show remote catch-syscall-packet
952 Set/show the use of the remote catch syscall feature.
956 ** The -var-set-format command now accepts the zero-hexadecimal
957 format. It outputs data in hexadecimal format with zero-padding on the
962 ** gdb.InferiorThread objects have a new attribute "global_num",
963 which refers to the thread's global thread ID. The existing
964 "num" attribute now refers to the thread's per-inferior number.
965 See "Per-inferior thread numbers" above.
966 ** gdb.InferiorThread objects have a new attribute "inferior", which
967 is the Inferior object the thread belongs to.
969 *** Changes in GDB 7.10
971 * Support for process record-replay and reverse debugging on aarch64*-linux*
972 targets has been added. GDB now supports recording of A64 instruction set
973 including advance SIMD instructions.
975 * Support for Sun's version of the "stabs" debug file format has been removed.
977 * GDB now honors the content of the file /proc/PID/coredump_filter
978 (PID is the process ID) on GNU/Linux systems. This file can be used
979 to specify the types of memory mappings that will be included in a
980 corefile. For more information, please refer to the manual page of
981 "core(5)". GDB also has a new command: "set use-coredump-filter
982 on|off". It allows to set whether GDB will read the content of the
983 /proc/PID/coredump_filter file when generating a corefile.
985 * The "info os" command on GNU/Linux can now display information on
987 "info os cpus" Listing of all cpus/cores on the system
989 * GDB has two new commands: "set serial parity odd|even|none" and
990 "show serial parity". These allows to set or show parity for the
993 * The "info source" command now displays the producer string if it was
994 present in the debug info. This typically includes the compiler version
995 and may include things like its command line arguments.
997 * The "info dll", an alias of the "info sharedlibrary" command,
998 is now available on all platforms.
1000 * Directory names supplied to the "set sysroot" commands may be
1001 prefixed with "target:" to tell GDB to access shared libraries from
1002 the target system, be it local or remote. This replaces the prefix
1003 "remote:". The default sysroot has been changed from "" to
1004 "target:". "remote:" is automatically converted to "target:" for
1005 backward compatibility.
1007 * The system root specified by "set sysroot" will be prepended to the
1008 filename of the main executable (if reported to GDB as absolute by
1009 the operating system) when starting processes remotely, and when
1010 attaching to already-running local or remote processes.
1012 * GDB now supports automatic location and retrieval of executable
1013 files from remote targets. Remote debugging can now be initiated
1014 using only a "target remote" or "target extended-remote" command
1015 (no "set sysroot" or "file" commands are required). See "New remote
1018 * The "dump" command now supports verilog hex format.
1020 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1022 * On GNU/Linux, GDB and gdbserver are now able to access executable
1023 and shared library files without a "set sysroot" command when
1024 attaching to processes running in different mount namespaces from
1025 the debugger. This makes it possible to attach to processes in
1026 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1027 See "New remote packets" below.
1029 * The "tui reg" command now provides completion for all of the
1030 available register groups, including target specific groups.
1032 * The HISTSIZE environment variable is no longer read when determining
1033 the size of GDB's command history. GDB now instead reads the dedicated
1034 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1035 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1040 ** Memory ports can now be unbuffered.
1044 ** gdb.Objfile objects have a new attribute "username",
1045 which is the name of the objfile as specified by the user,
1046 without, for example, resolving symlinks.
1047 ** You can now write frame unwinders in Python.
1048 ** gdb.Type objects have a new method "optimized_out",
1049 returning optimized out gdb.Value instance of this type.
1050 ** gdb.Value objects have new methods "reference_value" and
1051 "const_value" which return a reference to the value and a
1052 "const" version of the value respectively.
1056 maint print symbol-cache
1057 Print the contents of the symbol cache.
1059 maint print symbol-cache-statistics
1060 Print statistics of symbol cache usage.
1062 maint flush-symbol-cache
1063 Flush the contents of the symbol cache.
1067 Start branch trace recording using Branch Trace Store (BTS) format.
1070 Evaluate expression by using the compiler and print result.
1074 Explicit commands for enabling and disabling tui mode.
1077 set mpx bound on i386 and amd64
1078 Support for bound table investigation on Intel MPX enabled applications.
1082 Start branch trace recording using Intel Processor Trace format.
1085 Print information about branch tracing internals.
1087 maint btrace packet-history
1088 Print the raw branch tracing data.
1090 maint btrace clear-packet-history
1091 Discard the stored raw branch tracing data.
1094 Discard all branch tracing data. It will be fetched and processed
1095 anew by the next "record" command.
1100 Renamed from "set debug dwarf2-die".
1101 show debug dwarf-die
1102 Renamed from "show debug dwarf2-die".
1104 set debug dwarf-read
1105 Renamed from "set debug dwarf2-read".
1106 show debug dwarf-read
1107 Renamed from "show debug dwarf2-read".
1109 maint set dwarf always-disassemble
1110 Renamed from "maint set dwarf2 always-disassemble".
1111 maint show dwarf always-disassemble
1112 Renamed from "maint show dwarf2 always-disassemble".
1114 maint set dwarf max-cache-age
1115 Renamed from "maint set dwarf2 max-cache-age".
1116 maint show dwarf max-cache-age
1117 Renamed from "maint show dwarf2 max-cache-age".
1119 set debug dwarf-line
1120 show debug dwarf-line
1121 Control display of debugging info regarding DWARF line processing.
1124 show max-completions
1125 Set the maximum number of candidates to be considered during
1126 completion. The default value is 200. This limit allows GDB
1127 to avoid generating large completion lists, the computation of
1128 which can cause the debugger to become temporarily unresponsive.
1130 set history remove-duplicates
1131 show history remove-duplicates
1132 Control the removal of duplicate history entries.
1134 maint set symbol-cache-size
1135 maint show symbol-cache-size
1136 Control the size of the symbol cache.
1138 set|show record btrace bts buffer-size
1139 Set and show the size of the ring buffer used for branch tracing in
1141 The obtained size may differ from the requested size. Use "info
1142 record" to see the obtained buffer size.
1144 set debug linux-namespaces
1145 show debug linux-namespaces
1146 Control display of debugging info regarding Linux namespaces.
1148 set|show record btrace pt buffer-size
1149 Set and show the size of the ring buffer used for branch tracing in
1150 Intel Processor Trace format.
1151 The obtained size may differ from the requested size. Use "info
1152 record" to see the obtained buffer size.
1154 maint set|show btrace pt skip-pad
1155 Set and show whether PAD packets are skipped when computing the
1158 * The command 'thread apply all' can now support new option '-ascending'
1159 to call its specified command for all threads in ascending order.
1161 * Python/Guile scripting
1163 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1164 special section named `.debug_gdb_scripts'.
1166 * New remote packets
1168 qXfer:btrace-conf:read
1169 Return the branch trace configuration for the current thread.
1171 Qbtrace-conf:bts:size
1172 Set the requested ring buffer size for branch tracing in BTS format.
1175 Enable Intel Procesor Trace-based branch tracing for the current
1176 process. The remote stub reports support for this packet to GDB's
1179 Qbtrace-conf:pt:size
1180 Set the requested ring buffer size for branch tracing in Intel Processor
1184 Indicates a memory breakpoint instruction was executed, irrespective
1185 of whether it was GDB that planted the breakpoint or the breakpoint
1186 is hardcoded in the program. This is required for correct non-stop
1190 Indicates the target stopped for a hardware breakpoint. This is
1191 required for correct non-stop mode operation.
1194 Return information about files on the remote system.
1196 qXfer:exec-file:read
1197 Return the full absolute name of the file that was executed to
1198 create a process running on the remote system.
1201 Select the filesystem on which vFile: operations with filename
1202 arguments will operate. This is required for GDB to be able to
1203 access files on remote targets where the remote stub does not
1204 share a common filesystem with the inferior(s).
1207 Indicates that a fork system call was executed.
1210 Indicates that a vfork system call was executed.
1212 vforkdone stop reason
1213 Indicates that a vfork child of the specified process has executed
1214 an exec or exit, allowing the vfork parent to resume execution.
1216 fork-events and vfork-events features in qSupported
1217 The qSupported packet allows GDB to request support for fork and
1218 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1219 and the qSupported response can contain the corresponding
1220 'stubfeatures'. Set and show commands can be used to display
1221 whether these features are enabled.
1223 * Extended-remote fork events
1225 ** GDB now has support for fork events on extended-remote Linux
1226 targets. For targets with Linux kernels 2.5.60 and later, this
1227 enables follow-fork-mode and detach-on-fork for both fork and
1228 vfork, as well as fork and vfork catchpoints.
1230 * The info record command now shows the recording format and the
1231 branch tracing configuration for the current thread when using
1232 the btrace record target.
1233 For the BTS format, it shows the ring buffer size.
1235 * GDB now has support for DTrace USDT (Userland Static Defined
1236 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1238 * GDB now supports access to vector registers on S/390 GNU/Linux
1241 * Removed command line options
1243 -xdb HP-UX XDB compatibility mode.
1245 * Removed targets and native configurations
1247 HP/PA running HP-UX hppa*-*-hpux*
1248 Itanium running HP-UX ia64-*-hpux*
1250 * New configure options
1253 This configure option allows the user to build GDB with support for
1254 Intel Processor Trace (default: auto). This requires libipt.
1256 --with-libipt-prefix=PATH
1257 Specify the path to the version of libipt that GDB should use.
1258 $PATH/include should contain the intel-pt.h header and
1259 $PATH/lib should contain the libipt.so library.
1261 *** Changes in GDB 7.9.1
1265 ** Xmethods can now specify a result type.
1267 *** Changes in GDB 7.9
1269 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1273 ** You can now access frame registers from Python scripts.
1274 ** New attribute 'producer' for gdb.Symtab objects.
1275 ** gdb.Objfile objects have a new attribute "progspace",
1276 which is the gdb.Progspace object of the containing program space.
1277 ** gdb.Objfile objects have a new attribute "owner".
1278 ** gdb.Objfile objects have a new attribute "build_id",
1279 which is the build ID generated when the file was built.
1280 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1281 ** A new event "gdb.clear_objfiles" has been added, triggered when
1282 selecting a new file to debug.
1283 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1284 ** New function gdb.lookup_objfile.
1286 New events which are triggered when GDB modifies the state of the
1289 ** gdb.events.inferior_call_pre: Function call is about to be made.
1290 ** gdb.events.inferior_call_post: Function call has just been made.
1291 ** gdb.events.memory_changed: A memory location has been altered.
1292 ** gdb.events.register_changed: A register has been altered.
1294 * New Python-based convenience functions:
1296 ** $_caller_is(name [, number_of_frames])
1297 ** $_caller_matches(regexp [, number_of_frames])
1298 ** $_any_caller_is(name [, number_of_frames])
1299 ** $_any_caller_matches(regexp [, number_of_frames])
1301 * GDB now supports the compilation and injection of source code into
1302 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1303 to compile the source code to object code, and if successful, inject
1304 and execute that code within the current context of the inferior.
1305 Currently the C language is supported. The commands used to
1306 interface with this new feature are:
1308 compile code [-raw|-r] [--] [source code]
1309 compile file [-raw|-r] filename
1313 demangle [-l language] [--] name
1314 Demangle "name" in the specified language, or the current language
1315 if elided. This command is renamed from the "maint demangle" command.
1316 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1317 as "maint demangler-warning".
1319 queue-signal signal-name-or-number
1320 Queue a signal to be delivered to the thread when it is resumed.
1322 add-auto-load-scripts-directory directory
1323 Add entries to the list of directories from which to load auto-loaded
1326 maint print user-registers
1327 List all currently available "user" registers.
1329 compile code [-r|-raw] [--] [source code]
1330 Compile, inject, and execute in the inferior the executable object
1331 code produced by compiling the provided source code.
1333 compile file [-r|-raw] filename
1334 Compile and inject into the inferior the executable object code
1335 produced by compiling the source code stored in the filename
1338 * On resume, GDB now always passes the signal the program had stopped
1339 for to the thread the signal was sent to, even if the user changed
1340 threads before resuming. Previously GDB would often (but not
1341 always) deliver the signal to the thread that happens to be current
1344 * Conversely, the "signal" command now consistently delivers the
1345 requested signal to the current thread. GDB now asks for
1346 confirmation if the program had stopped for a signal and the user
1347 switched threads meanwhile.
1349 * "breakpoint always-inserted" modes "off" and "auto" merged.
1351 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1352 won't remove breakpoints from the target until all threads stop,
1353 even in non-stop mode. The "auto" mode has been removed, and "off"
1354 is now the default mode.
1358 set debug symbol-lookup
1359 show debug symbol-lookup
1360 Control display of debugging info regarding symbol lookup.
1364 ** The -list-thread-groups command outputs an exit-code field for
1365 inferiors that have exited.
1369 MIPS SDE mips*-sde*-elf*
1373 Support for these obsolete configurations has been removed.
1375 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1376 SGI Irix-5.x mips-*-irix5*
1377 SGI Irix-6.x mips-*-irix6*
1378 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1379 VAX running Ultrix vax-*-ultrix*
1381 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1382 and "assf"), have been removed. Use the "sharedlibrary" command, or
1383 its alias "share", instead.
1385 *** Changes in GDB 7.8
1387 * New command line options
1390 This is an alias for the --data-directory option.
1392 * GDB supports printing and modifying of variable length automatic arrays
1393 as specified in ISO C99.
1395 * The ARM simulator now supports instruction level tracing
1396 with or without disassembly.
1400 GDB now has support for scripting using Guile. Whether this is
1401 available is determined at configure time.
1402 Guile version 2.0 or greater is required.
1403 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1405 * New commands (for set/show, see "New options" below)
1409 Invoke CODE by passing it to the Guile interpreter.
1413 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1415 info auto-load guile-scripts [regexp]
1416 Print the list of automatically loaded Guile scripts.
1418 * The source command is now capable of sourcing Guile scripts.
1419 This feature is dependent on the debugger being built with Guile support.
1423 set print symbol-loading (off|brief|full)
1424 show print symbol-loading
1425 Control whether to print informational messages when loading symbol
1426 information for a file. The default is "full", but when debugging
1427 programs with large numbers of shared libraries the amount of output
1428 becomes less useful.
1430 set guile print-stack (none|message|full)
1431 show guile print-stack
1432 Show a stack trace when an error is encountered in a Guile script.
1434 set auto-load guile-scripts (on|off)
1435 show auto-load guile-scripts
1436 Control auto-loading of Guile script files.
1438 maint ada set ignore-descriptive-types (on|off)
1439 maint ada show ignore-descriptive-types
1440 Control whether the debugger should ignore descriptive types in Ada
1441 programs. The default is not to ignore the descriptive types. See
1442 the user manual for more details on descriptive types and the intended
1443 usage of this option.
1445 set auto-connect-native-target
1447 Control whether GDB is allowed to automatically connect to the
1448 native target for the run, attach, etc. commands when not connected
1449 to any target yet. See also "target native" below.
1451 set record btrace replay-memory-access (read-only|read-write)
1452 show record btrace replay-memory-access
1453 Control what memory accesses are allowed during replay.
1455 maint set target-async (on|off)
1456 maint show target-async
1457 This controls whether GDB targets operate in synchronous or
1458 asynchronous mode. Normally the default is asynchronous, if it is
1459 available; but this can be changed to more easily debug problems
1460 occurring only in synchronous mode.
1462 set mi-async (on|off)
1464 Control whether MI asynchronous mode is preferred. This supersedes
1465 "set target-async" of previous GDB versions.
1467 * "set target-async" is deprecated as a CLI option and is now an alias
1468 for "set mi-async" (only puts MI into async mode).
1470 * Background execution commands (e.g., "c&", "s&", etc.) are now
1471 possible ``out of the box'' if the target supports them. Previously
1472 the user would need to explicitly enable the possibility with the
1473 "set target-async on" command.
1475 * New features in the GDB remote stub, GDBserver
1477 ** New option --debug-format=option1[,option2,...] allows one to add
1478 additional text to each output. At present only timestamps
1479 are supported: --debug-format=timestamps.
1480 Timestamps can also be turned on with the
1481 "monitor set debug-format timestamps" command from GDB.
1483 * The 'record instruction-history' command now starts counting instructions
1484 at one. This also affects the instruction ranges reported by the
1485 'record function-call-history' command when given the /i modifier.
1487 * The command 'record function-call-history' supports a new modifier '/c' to
1488 indent the function names based on their call stack depth.
1489 The fields for the '/i' and '/l' modifier have been reordered.
1490 The source line range is now prefixed with 'at'.
1491 The instruction range is now prefixed with 'inst'.
1492 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1493 "record instruction-history" and "list" commands.
1495 * The ranges given as arguments to the 'record function-call-history' and
1496 'record instruction-history' commands are now inclusive.
1498 * The btrace record target now supports the 'record goto' command.
1499 For locations inside the execution trace, the back trace is computed
1500 based on the information stored in the execution trace.
1502 * The btrace record target supports limited reverse execution and replay.
1503 The target does not record data and therefore does not allow reading
1504 memory or registers.
1506 * The "catch syscall" command now works on s390*-linux* targets.
1508 * The "compare-sections" command is no longer specific to target
1509 remote. It now works with all targets.
1511 * All native targets are now consistently called "native".
1512 Consequently, the "target child", "target GNU", "target djgpp",
1513 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1514 commands have been replaced with "target native". The QNX/NTO port
1515 leaves the "procfs" target in place and adds a "native" target for
1516 consistency with other ports. The impact on users should be minimal
1517 as these commands previously either throwed an error, or were
1518 no-ops. The target's name is visible in the output of the following
1519 commands: "help target", "info target", "info files", "maint print
1522 * The "target native" command now connects to the native target. This
1523 can be used to launch native programs even when "set
1524 auto-connect-native-target" is set to off.
1526 * GDB now supports access to Intel MPX registers on GNU/Linux.
1528 * Support for Intel AVX-512 registers on GNU/Linux.
1529 Support displaying and modifying Intel AVX-512 registers
1530 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1532 * New remote packets
1534 qXfer:btrace:read's annex
1535 The qXfer:btrace:read packet supports a new annex 'delta' to read
1536 branch trace incrementally.
1540 ** Valid Python operations on gdb.Value objects representing
1541 structs/classes invoke the corresponding overloaded operators if
1543 ** New `Xmethods' feature in the Python API. Xmethods are
1544 additional methods or replacements for existing methods of a C++
1545 class. This feature is useful for those cases where a method
1546 defined in C++ source code could be inlined or optimized out by
1547 the compiler, making it unavailable to GDB.
1550 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1552 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1553 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1554 its alias "share", instead.
1556 * The commands "set remotebaud" and "show remotebaud" are no longer
1557 supported. Use "set serial baud" and "show serial baud" (respectively)
1562 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1563 target-async". The latter is left as a deprecated alias of the
1564 former for backward compatibility. If the target supports it,
1565 CLI background execution commands are now always possible by
1566 default, independently of whether the frontend stated a
1567 preference for asynchronous execution with "-gdb-set mi-async".
1568 Previously "-gdb-set target-async off" affected both MI execution
1569 commands and CLI execution commands.
1571 *** Changes in GDB 7.7
1573 * Improved support for process record-replay and reverse debugging on
1574 arm*-linux* targets. Support for thumb32 and syscall instruction
1575 recording has been added.
1577 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1579 * GDB now supports Fission DWP file format version 2.
1580 http://gcc.gnu.org/wiki/DebugFission
1582 * New convenience function "$_isvoid", to check whether an expression
1583 is void. A void expression is an expression where the type of the
1584 result is "void". For example, some convenience variables may be
1585 "void" when evaluated (e.g., "$_exitcode" before the execution of
1586 the program being debugged; or an undefined convenience variable).
1587 Another example, when calling a function whose return type is
1590 * The "maintenance print objfiles" command now takes an optional regexp.
1592 * The "catch syscall" command now works on arm*-linux* targets.
1594 * GDB now consistently shows "<not saved>" when printing values of
1595 registers the debug info indicates have not been saved in the frame
1596 and there's nowhere to retrieve them from
1597 (callee-saved/call-clobbered registers):
1602 (gdb) info registers rax
1605 Before, the former would print "<optimized out>", and the latter
1606 "*value not available*".
1608 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1613 ** Frame filters and frame decorators have been added.
1614 ** Temporary breakpoints are now supported.
1615 ** Line tables representation has been added.
1616 ** New attribute 'parent_type' for gdb.Field objects.
1617 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1618 ** New attribute 'name' for gdb.Type objects.
1622 Nios II ELF nios2*-*-elf
1623 Nios II GNU/Linux nios2*-*-linux
1624 Texas Instruments MSP430 msp430*-*-elf
1626 * Removed native configurations
1628 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1629 been removed. ELF variants of these configurations are kept supported.
1631 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1632 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1633 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1634 i[34567]86-*-openbsd3.[0-3]
1635 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1636 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1637 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1641 Like "catch throw", but catches a re-thrown exception.
1642 maint check-psymtabs
1643 Renamed from old "maint check-symtabs".
1645 Perform consistency checks on symtabs.
1646 maint expand-symtabs
1647 Expand symtabs matching an optional regexp.
1650 Display the details of GDB configure-time options.
1652 maint set|show per-command
1653 maint set|show per-command space
1654 maint set|show per-command time
1655 maint set|show per-command symtab
1656 Enable display of per-command gdb resource usage.
1658 remove-symbol-file FILENAME
1659 remove-symbol-file -a ADDRESS
1660 Remove a symbol file added via add-symbol-file. The file to remove
1661 can be identified by its filename or by an address that lies within
1662 the boundaries of this symbol file in memory.
1665 info exceptions REGEXP
1666 Display the list of Ada exceptions defined in the program being
1667 debugged. If provided, only the exceptions whose names match REGEXP
1672 set debug symfile off|on
1674 Control display of debugging info regarding reading symbol files and
1675 symbol tables within those files
1677 set print raw frame-arguments
1678 show print raw frame-arguments
1679 Set/show whether to print frame arguments in raw mode,
1680 disregarding any defined pretty-printers.
1682 set remote trace-status-packet
1683 show remote trace-status-packet
1684 Set/show the use of remote protocol qTStatus packet.
1688 Control display of debugging messages related to Nios II targets.
1692 Control whether target-assisted range stepping is enabled.
1694 set startup-with-shell
1695 show startup-with-shell
1696 Specifies whether Unix child processes are started via a shell or
1701 Use the target memory cache for accesses to the code segment. This
1702 improves performance of remote debugging (particularly disassembly).
1704 * You can now use a literal value 'unlimited' for options that
1705 interpret 0 or -1 as meaning "unlimited". E.g., "set
1706 trace-buffer-size unlimited" is now an alias for "set
1707 trace-buffer-size -1" and "set height unlimited" is now an alias for
1710 * The "set debug symtab-create" debugging option of GDB has been changed to
1711 accept a verbosity level. 0 means "off", 1 provides basic debugging
1712 output, and values of 2 or greater provides more verbose output.
1714 * New command-line options
1716 Display the details of GDB configure-time options.
1718 * The command 'tsave' can now support new option '-ctf' to save trace
1719 buffer in Common Trace Format.
1721 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1724 * GDB now implements the the C++ 'typeid' operator.
1726 * The new convenience variable $_exception holds the exception being
1727 thrown or caught at an exception-related catchpoint.
1729 * The exception-related catchpoints, like "catch throw", now accept a
1730 regular expression which can be used to filter exceptions by type.
1732 * The new convenience variable $_exitsignal is automatically set to
1733 the terminating signal number when the program being debugged dies
1734 due to an uncaught signal.
1738 ** All MI commands now accept an optional "--language" option.
1739 Support for this feature can be verified by using the "-list-features"
1740 command, which should contain "language-option".
1742 ** The new command -info-gdb-mi-command allows the user to determine
1743 whether a GDB/MI command is supported or not.
1745 ** The "^error" result record returned when trying to execute an undefined
1746 GDB/MI command now provides a variable named "code" whose content is the
1747 "undefined-command" error code. Support for this feature can be verified
1748 by using the "-list-features" command, which should contain
1749 "undefined-command-error-code".
1751 ** The -trace-save MI command can optionally save trace buffer in Common
1754 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1756 ** The command -data-list-register-values now accepts an optional
1757 "--skip-unavailable" option. When used, only the available registers
1760 ** The new command -trace-frame-collected dumps collected variables,
1761 computed expressions, tvars, memory and registers in a traceframe.
1763 ** The commands -stack-list-locals, -stack-list-arguments and
1764 -stack-list-variables now accept an option "--skip-unavailable".
1765 When used, only the available locals or arguments are displayed.
1767 ** The -exec-run command now accepts an optional "--start" option.
1768 When used, the command follows the same semantics as the "start"
1769 command, stopping the program's execution at the start of its
1770 main subprogram. Support for this feature can be verified using
1771 the "-list-features" command, which should contain
1772 "exec-run-start-option".
1774 ** The new commands -catch-assert and -catch-exceptions insert
1775 catchpoints stopping the program when Ada exceptions are raised.
1777 ** The new command -info-ada-exceptions provides the equivalent of
1778 the new "info exceptions" command.
1780 * New system-wide configuration scripts
1781 A GDB installation now provides scripts suitable for use as system-wide
1782 configuration scripts for the following systems:
1786 * GDB now supports target-assigned range stepping with remote targets.
1787 This improves the performance of stepping source lines by reducing
1788 the number of control packets from/to GDB. See "New remote packets"
1791 * GDB now understands the element 'tvar' in the XML traceframe info.
1792 It has the id of the collected trace state variables.
1794 * On S/390 targets that provide the transactional-execution feature,
1795 the program interruption transaction diagnostic block (TDB) is now
1796 represented as a number of additional "registers" in GDB.
1798 * New remote packets
1802 The vCont packet supports a new 'r' action, that tells the remote
1803 stub to step through an address range itself, without GDB
1804 involvemement at each single-step.
1806 qXfer:libraries-svr4:read's annex
1807 The previously unused annex of the qXfer:libraries-svr4:read packet
1808 is now used to support passing an argument list. The remote stub
1809 reports support for this argument list to GDB's qSupported query.
1810 The defined arguments are "start" and "prev", used to reduce work
1811 necessary for library list updating, resulting in significant
1814 * New features in the GDB remote stub, GDBserver
1816 ** GDBserver now supports target-assisted range stepping. Currently
1817 enabled on x86/x86_64 GNU/Linux targets.
1819 ** GDBserver now adds element 'tvar' in the XML in the reply to
1820 'qXfer:traceframe-info:read'. It has the id of the collected
1821 trace state variables.
1823 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1826 * New 'z' formatter for printing and examining memory, this displays the
1827 value as hexadecimal zero padded on the left to the size of the type.
1829 * GDB can now use Windows x64 unwinding data.
1831 * The "set remotebaud" command has been replaced by "set serial baud".
1832 Similarly, "show remotebaud" has been replaced by "show serial baud".
1833 The "set remotebaud" and "show remotebaud" commands are still available
1834 to provide backward compatibility with older versions of GDB.
1836 *** Changes in GDB 7.6
1838 * Target record has been renamed to record-full.
1839 Record/replay is now enabled with the "record full" command.
1840 This also affects settings that are associated with full record/replay
1841 that have been moved from "set/show record" to "set/show record full":
1843 set|show record full insn-number-max
1844 set|show record full stop-at-limit
1845 set|show record full memory-query
1847 * A new record target "record-btrace" has been added. The new target
1848 uses hardware support to record the control-flow of a process. It
1849 does not support replaying the execution, but it implements the
1850 below new commands for investigating the recorded execution log.
1851 This new recording method can be enabled using:
1855 The "record-btrace" target is only available on Intel Atom processors
1856 and requires a Linux kernel 2.6.32 or later.
1858 * Two new commands have been added for record/replay to give information
1859 about the recorded execution without having to replay the execution.
1860 The commands are only supported by "record btrace".
1862 record instruction-history prints the execution history at
1863 instruction granularity
1865 record function-call-history prints the execution history at
1866 function granularity
1868 * New native configurations
1870 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1871 FreeBSD/powerpc powerpc*-*-freebsd
1872 x86_64/Cygwin x86_64-*-cygwin*
1873 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1877 ARM AArch64 aarch64*-*-elf
1878 ARM AArch64 GNU/Linux aarch64*-*-linux
1879 Lynx 178 PowerPC powerpc-*-lynx*178
1880 x86_64/Cygwin x86_64-*-cygwin*
1881 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1883 * If the configured location of system.gdbinit file (as given by the
1884 --with-system-gdbinit option at configure time) is in the
1885 data-directory (as specified by --with-gdb-datadir at configure
1886 time) or in one of its subdirectories, then GDB will look for the
1887 system-wide init file in the directory specified by the
1888 --data-directory command-line option.
1890 * New command line options:
1892 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1893 other initialization files, unlike -nx which disables all of them.
1895 * Removed command line options
1897 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1900 * The 'ptype' and 'whatis' commands now accept an argument to control
1903 * 'info proc' now works on some core files.
1907 ** Vectors can be created with gdb.Type.vector.
1909 ** Python's atexit.register now works in GDB.
1911 ** Types can be pretty-printed via a Python API.
1913 ** Python 3 is now supported (in addition to Python 2.4 or later)
1915 ** New class gdb.Architecture exposes GDB's internal representation
1916 of architecture in the Python API.
1918 ** New method Frame.architecture returns the gdb.Architecture object
1919 corresponding to the frame's architecture.
1921 * New Python-based convenience functions:
1923 ** $_memeq(buf1, buf2, length)
1924 ** $_streq(str1, str2)
1926 ** $_regex(str, regex)
1928 * The 'cd' command now defaults to using '~' (the home directory) if not
1931 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1932 default for GCC since November 2000.
1934 * The command 'forward-search' can now be abbreviated as 'fo'.
1936 * The command 'info tracepoints' can now display 'installed on target'
1937 or 'not installed on target' for each non-pending location of tracepoint.
1939 * New configure options
1941 --enable-libmcheck/--disable-libmcheck
1942 By default, development versions are built with -lmcheck on hosts
1943 that support it, in order to help track memory corruption issues.
1944 Release versions, on the other hand, are built without -lmcheck
1945 by default. The --enable-libmcheck/--disable-libmcheck configure
1946 options allow the user to override that default.
1947 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1948 This configure option allows the user to build GDB with
1949 libbabeltrace using which GDB can read Common Trace Format data.
1951 * New commands (for set/show, see "New options" below)
1954 Catch signals. This is similar to "handle", but allows commands and
1955 conditions to be attached.
1958 List the BFDs known to GDB.
1960 python-interactive [command]
1962 Start a Python interactive prompt, or evaluate the optional command
1963 and print the result of expressions.
1966 "py" is a new alias for "python".
1968 enable type-printer [name]...
1969 disable type-printer [name]...
1970 Enable or disable type printers.
1974 ** For the Renesas Super-H architecture, the "regs" command has been removed
1975 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1980 set print type methods (on|off)
1981 show print type methods
1982 Control whether method declarations are displayed by "ptype".
1983 The default is to show them.
1985 set print type typedefs (on|off)
1986 show print type typedefs
1987 Control whether typedef definitions are displayed by "ptype".
1988 The default is to show them.
1990 set filename-display basename|relative|absolute
1991 show filename-display
1992 Control the way in which filenames is displayed.
1993 The default is "relative", which preserves previous behavior.
1995 set trace-buffer-size
1996 show trace-buffer-size
1997 Request target to change the size of trace buffer.
1999 set remote trace-buffer-size-packet auto|on|off
2000 show remote trace-buffer-size-packet
2001 Control the use of the remote protocol `QTBuffer:size' packet.
2005 Control display of debugging messages related to ARM AArch64.
2008 set debug coff-pe-read
2009 show debug coff-pe-read
2010 Control display of debugging messages related to reading of COFF/PE
2015 Control display of debugging messages related to Mach-O symbols
2018 set debug notification
2019 show debug notification
2020 Control display of debugging info for async remote notification.
2024 ** Command parameter changes are now notified using new async record
2025 "=cmd-param-changed".
2026 ** Trace frame changes caused by command "tfind" are now notified using
2027 new async record "=traceframe-changed".
2028 ** The creation, deletion and modification of trace state variables
2029 are now notified using new async records "=tsv-created",
2030 "=tsv-deleted" and "=tsv-modified".
2031 ** The start and stop of process record are now notified using new
2032 async record "=record-started" and "=record-stopped".
2033 ** Memory changes are now notified using new async record
2035 ** The data-disassemble command response will include a "fullname" field
2036 containing the absolute file name when source has been requested.
2037 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2038 command, to allow pattern filling of memory areas.
2039 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2040 library load/unload events.
2041 ** The response to breakpoint commands and breakpoint async records
2042 includes an "installed" field containing a boolean state about each
2043 non-pending tracepoint location is whether installed on target or not.
2044 ** Output of the "-trace-status" command includes a "trace-file" field
2045 containing the name of the trace file being examined. This field is
2046 optional, and only present when examining a trace file.
2047 ** The "fullname" field is now always present along with the "file" field,
2048 even if the file cannot be found by GDB.
2050 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2051 You must have the LZMA library available when configuring GDB for this
2052 feature to be enabled. For more information, see:
2053 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2055 * New remote packets
2058 Set the size of trace buffer. The remote stub reports support for this
2059 packet to gdb's qSupported query.
2062 Enable Branch Trace Store (BTS)-based branch tracing for the current
2063 thread. The remote stub reports support for this packet to gdb's
2067 Disable branch tracing for the current thread. The remote stub reports
2068 support for this packet to gdb's qSupported query.
2071 Read the traced branches for the current thread. The remote stub
2072 reports support for this packet to gdb's qSupported query.
2074 *** Changes in GDB 7.5
2076 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2077 for more x32 ABI info.
2079 * GDB now supports access to MIPS DSP registers on Linux targets.
2081 * GDB now supports debugging microMIPS binaries.
2083 * The "info os" command on GNU/Linux can now display information on
2084 several new classes of objects managed by the operating system:
2085 "info os procgroups" lists process groups
2086 "info os files" lists file descriptors
2087 "info os sockets" lists internet-domain sockets
2088 "info os shm" lists shared-memory regions
2089 "info os semaphores" lists semaphores
2090 "info os msg" lists message queues
2091 "info os modules" lists loaded kernel modules
2093 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2094 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2095 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2096 options and inspect the probe arguments using the new $_probe_arg family
2097 of convenience variables. You can obtain more information about SystemTap
2098 in <http://sourceware.org/systemtap/>.
2100 * GDB now supports reversible debugging on ARM, it allows you to
2101 debug basic ARM and THUMB instructions, and provides
2102 record/replay support.
2104 * The option "symbol-reloading" has been deleted as it is no longer used.
2108 ** GDB commands implemented in Python can now be put in command class
2111 ** The "maint set python print-stack on|off" is now deleted.
2113 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2114 apply "flag enum"-style pretty-printing to any enum.
2116 ** gdb.lookup_symbol can now work when there is no current frame.
2118 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2119 the source at which the symbol was defined.
2121 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2122 method 'value'. The former indicates whether the symbol needs a
2123 frame in order to compute its value, and the latter computes the
2126 ** A new method 'referenced_value' on gdb.Value objects which can
2127 dereference pointer as well as C++ reference values.
2129 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2130 which return the global and static blocks (as gdb.Block objects),
2131 of the underlying symbol table, respectively.
2133 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2134 object associated with a PC value.
2136 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2137 of the address range occupied by code for the current source line.
2139 * Go language support.
2140 GDB now supports debugging programs written in the Go programming
2143 * GDBserver now supports stdio connections.
2144 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2146 * The binary "gdbtui" can no longer be built or installed.
2147 Use "gdb -tui" instead.
2149 * GDB will now print "flag" enums specially. A flag enum is one where
2150 all the enumerator values have no bits in common when pairwise
2151 "and"ed. When printing a value whose type is a flag enum, GDB will
2152 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2153 (gdb) print (enum E) 3
2156 * The filename part of a linespec will now match trailing components
2157 of a source file name. For example, "break gcc/expr.c:1000" will
2158 now set a breakpoint in build/gcc/expr.c, but not
2159 build/libcpp/expr.c.
2161 * The "info proc" and "generate-core-file" commands will now also
2162 work on remote targets connected to GDBserver on Linux.
2164 * The command "info catch" has been removed. It has been disabled
2165 since December 2007.
2167 * The "catch exception" and "catch assert" commands now accept
2168 a condition at the end of the command, much like the "break"
2169 command does. For instance:
2171 (gdb) catch exception Constraint_Error if Barrier = True
2173 Previously, it was possible to add a condition to such catchpoints,
2174 but it had to be done as a second step, after the catchpoint had been
2175 created, using the "condition" command.
2177 * The "info static-tracepoint-marker" command will now also work on
2178 native Linux targets with in-process agent.
2180 * GDB can now set breakpoints on inlined functions.
2182 * The .gdb_index section has been updated to include symbols for
2183 inlined functions. GDB will ignore older .gdb_index sections by
2184 default, which could cause symbol files to be loaded more slowly
2185 until their .gdb_index sections can be recreated. The new command
2186 "set use-deprecated-index-sections on" will cause GDB to use any older
2187 .gdb_index sections it finds. This will restore performance, but the
2188 ability to set breakpoints on inlined functions will be lost in symbol
2189 files with older .gdb_index sections.
2191 The .gdb_index section has also been updated to record more information
2192 about each symbol. This speeds up the "info variables", "info functions"
2193 and "info types" commands when used with programs having the .gdb_index
2194 section, as well as speeding up debugging with shared libraries using
2195 the .gdb_index section.
2197 * Ada support for GDB/MI Variable Objects has been added.
2199 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2204 ** New command -info-os is the MI equivalent of "info os".
2206 ** Output logs ("set logging" and related) now include MI output.
2210 ** "set use-deprecated-index-sections on|off"
2211 "show use-deprecated-index-sections on|off"
2212 Controls the use of deprecated .gdb_index sections.
2214 ** "catch load" and "catch unload" can be used to stop when a shared
2215 library is loaded or unloaded, respectively.
2217 ** "enable count" can be used to auto-disable a breakpoint after
2220 ** "info vtbl" can be used to show the virtual method tables for
2221 C++ and Java objects.
2223 ** "explore" and its sub commands "explore value" and "explore type"
2224 can be used to recursively explore values and types of
2225 expressions. These commands are available only if GDB is
2226 configured with '--with-python'.
2228 ** "info auto-load" shows status of all kinds of auto-loaded files,
2229 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2230 sequences of commands files, "info auto-load python-scripts"
2231 shows status of auto-loading Python script files,
2232 "info auto-load local-gdbinit" shows status of loading init file
2233 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2234 status of inferior specific thread debugging shared library loading.
2236 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2237 and "show auto-load-scripts" commands have been deprecated, use their
2238 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2239 and "show auto-load python-scripts" counterparts instead.
2241 ** "dprintf location,format,args..." creates a dynamic printf, which
2242 is basically a breakpoint that does a printf and immediately
2243 resumes your program's execution, so it is like a printf that you
2244 can insert dynamically at runtime instead of at compiletime.
2246 ** "set print symbol"
2248 Controls whether GDB attempts to display the symbol, if any,
2249 corresponding to addresses it prints. This defaults to "on", but
2250 you can set it to "off" to restore GDB's previous behavior.
2252 * Deprecated commands
2254 ** For the Renesas Super-H architecture, the "regs" command has been
2255 deprecated, and "info all-registers" should be used instead.
2259 Renesas RL78 rl78-*-elf
2260 HP OpenVMS ia64 ia64-hp-openvms*
2262 * GDBserver supports evaluation of breakpoint conditions. When
2263 support is advertised by GDBserver, GDB may be told to send the
2264 breakpoint conditions in bytecode form to GDBserver. GDBserver
2265 will only report the breakpoint trigger to GDB when its condition
2270 set mips compression
2271 show mips compression
2272 Select the compressed ISA encoding used in functions that have no symbol
2273 information available. The encoding can be set to either of:
2276 and is updated automatically from ELF file flags if available.
2278 set breakpoint condition-evaluation
2279 show breakpoint condition-evaluation
2280 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2281 GDBserver ("target"). Default option "auto" chooses the most efficient
2283 This option can improve debugger efficiency depending on the speed of the
2287 Disable auto-loading globally.
2290 Show auto-loading setting of all kinds of auto-loaded files.
2292 set auto-load gdb-scripts on|off
2293 show auto-load gdb-scripts
2294 Control auto-loading of GDB canned sequences of commands files.
2296 set auto-load python-scripts on|off
2297 show auto-load python-scripts
2298 Control auto-loading of Python script files.
2300 set auto-load local-gdbinit on|off
2301 show auto-load local-gdbinit
2302 Control loading of init file (.gdbinit) from current directory.
2304 set auto-load libthread-db on|off
2305 show auto-load libthread-db
2306 Control auto-loading of inferior specific thread debugging shared library.
2308 set auto-load scripts-directory <dir1>[:<dir2>...]
2309 show auto-load scripts-directory
2310 Set a list of directories from which to load auto-loaded scripts.
2311 Automatically loaded Python scripts and GDB scripts are located in one
2312 of the directories listed by this option.
2313 The delimiter (':' above) may differ according to the host platform.
2315 set auto-load safe-path <dir1>[:<dir2>...]
2316 show auto-load safe-path
2317 Set a list of directories from which it is safe to auto-load files.
2318 The delimiter (':' above) may differ according to the host platform.
2320 set debug auto-load on|off
2321 show debug auto-load
2322 Control display of debugging info for auto-loading the files above.
2324 set dprintf-style gdb|call|agent
2326 Control the way in which a dynamic printf is performed; "gdb"
2327 requests a GDB printf command, while "call" causes dprintf to call a
2328 function in the inferior. "agent" requests that the target agent
2329 (such as GDBserver) do the printing.
2331 set dprintf-function <expr>
2332 show dprintf-function
2333 set dprintf-channel <expr>
2334 show dprintf-channel
2335 Set the function and optional first argument to the call when using
2336 the "call" style of dynamic printf.
2338 set disconnected-dprintf on|off
2339 show disconnected-dprintf
2340 Control whether agent-style dynamic printfs continue to be in effect
2341 after GDB disconnects.
2343 * New configure options
2345 --with-auto-load-dir
2346 Configure default value for the 'set auto-load scripts-directory'
2347 setting above. It defaults to '$debugdir:$datadir/auto-load',
2348 $debugdir representing global debugging info directories (available
2349 via 'show debug-file-directory') and $datadir representing GDB's data
2350 directory (available via 'show data-directory').
2352 --with-auto-load-safe-path
2353 Configure default value for the 'set auto-load safe-path' setting
2354 above. It defaults to the --with-auto-load-dir setting.
2356 --without-auto-load-safe-path
2357 Set 'set auto-load safe-path' to '/', effectively disabling this
2360 * New remote packets
2362 z0/z1 conditional breakpoints extension
2364 The z0/z1 breakpoint insertion packets have been extended to carry
2365 a list of conditional expressions over to the remote stub depending on the
2366 condition evaluation mode. The use of this extension can be controlled
2367 via the "set remote conditional-breakpoints-packet" command.
2371 Specify the signals which the remote stub may pass to the debugged
2372 program without GDB involvement.
2374 * New command line options
2376 --init-command=FILE, -ix Like --command, -x but execute it
2377 before loading inferior.
2378 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2379 execute it before loading inferior.
2381 *** Changes in GDB 7.4
2383 * GDB now handles ambiguous linespecs more consistently; the existing
2384 FILE:LINE support has been expanded to other types of linespecs. A
2385 breakpoint will now be set on all matching locations in all
2386 inferiors, and locations will be added or removed according to
2389 * GDB now allows you to skip uninteresting functions and files when
2390 stepping with the "skip function" and "skip file" commands.
2392 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2393 and "show remote hardware-watchpoint-length-limit". These allows to
2394 set or show the maximum length limit (in bytes) of a remote
2395 target hardware watchpoint.
2397 This allows e.g. to use "unlimited" hardware watchpoints with the
2398 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2399 watchpoints are slower than real hardware watchpoints but are
2400 significantly faster than gdb software watchpoints.
2404 ** The register_pretty_printer function in module gdb.printing now takes
2405 an optional `replace' argument. If True, the new printer replaces any
2408 ** The "maint set python print-stack on|off" command has been
2409 deprecated and will be deleted in GDB 7.5.
2410 A new command: "set python print-stack none|full|message" has
2411 replaced it. Additionally, the default for "print-stack" is
2412 now "message", which just prints the error message without
2415 ** A prompt substitution hook (prompt_hook) is now available to the
2418 ** A new Python module, gdb.prompt has been added to the GDB Python
2419 modules library. This module provides functionality for
2420 escape sequences in prompts (used by set/show
2421 extended-prompt). These escape sequences are replaced by their
2422 corresponding value.
2424 ** Python commands and convenience-functions located in
2425 'data-directory'/python/gdb/command and
2426 'data-directory'/python/gdb/function are now automatically loaded
2429 ** Blocks now provide four new attributes. global_block and
2430 static_block will return the global and static blocks
2431 respectively. is_static and is_global are boolean attributes
2432 that indicate if the block is one of those two types.
2434 ** Symbols now provide the "type" attribute, the type of the symbol.
2436 ** The "gdb.breakpoint" function has been deprecated in favor of
2439 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2440 of a function. This class is based on the "finish" command
2441 available in the CLI.
2443 ** Type objects for struct and union types now allow access to
2444 the fields using standard Python dictionary (mapping) methods.
2445 For example, "some_type['myfield']" now works, as does
2446 "some_type.items()".
2448 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2451 ** A new function, "deep_items" has been added to the gdb.types
2452 module in the GDB Python modules library. This function returns
2453 an iterator over the fields of a struct or union type. Unlike
2454 the standard Python "iteritems" method, it will recursively traverse
2455 any anonymous fields.
2459 ** "*stopped" events can report several new "reason"s, such as
2462 ** Breakpoint changes are now notified using new async records, like
2463 "=breakpoint-modified".
2465 ** New command -ada-task-info.
2467 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2468 $sdir specifies the default system locations of shared libraries.
2469 $pdir specifies the directory where the libpthread used by the application
2472 GDB no longer looks in $sdir and $pdir after it has searched the directories
2473 mentioned in libthread-db-search-path. If you want to search those
2474 directories, they must be specified in libthread-db-search-path.
2475 The default value of libthread-db-search-path on GNU/Linux and Solaris
2476 systems is now "$sdir:$pdir".
2478 $pdir is not supported by gdbserver, it is currently ignored.
2479 $sdir is supported by gdbserver.
2481 * New configure option --with-iconv-bin.
2482 When using the internationalization support like the one in the GNU C
2483 library, GDB will invoke the "iconv" program to get a list of supported
2484 character sets. If this program lives in a non-standard location, one can
2485 use this option to specify where to find it.
2487 * When natively debugging programs on PowerPC BookE processors running
2488 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2489 watchpoints, which specify a mask in addition to an address to watch.
2490 The mask specifies that some bits of an address (the bits which are
2491 reset in the mask) should be ignored when matching the address accessed
2492 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2493 section in the user manual for more details.
2495 * The new option --once causes GDBserver to stop listening for connections once
2496 the first connection is made. The listening port used by GDBserver will
2497 become available after that.
2499 * New commands "info macros" and "alias" have been added.
2501 * New function parameters suffix @entry specifies value of function parameter
2502 at the time the function got called. Entry values are available only since
2508 "!" is now an alias of the "shell" command.
2509 Note that no space is needed between "!" and SHELL COMMAND.
2513 watch EXPRESSION mask MASK_VALUE
2514 The watch command now supports the mask argument which allows creation
2515 of masked watchpoints, if the current architecture supports this feature.
2517 info auto-load-scripts [REGEXP]
2518 This command was formerly named "maintenance print section-scripts".
2519 It is now generally useful and is no longer a maintenance-only command.
2521 info macro [-all] [--] MACRO
2522 The info macro command has new options `-all' and `--'. The first for
2523 printing all definitions of a macro. The second for explicitly specifying
2524 the end of arguments and the beginning of the macro name in case the macro
2525 name starts with a hyphen.
2527 collect[/s] EXPRESSIONS
2528 The tracepoint collect command now takes an optional modifier "/s"
2529 that directs it to dereference pointer-to-character types and
2530 collect the bytes of memory up to a zero byte. The behavior is
2531 similar to what you see when you use the regular print command on a
2532 string. An optional integer following the "/s" sets a bound on the
2533 number of bytes that will be collected.
2536 The trace start command now interprets any supplied arguments as a
2537 note to be recorded with the trace run, with an effect similar to
2538 setting the variable trace-notes.
2541 The trace stop command now interprets any arguments as a note to be
2542 mentioned along with the tstatus report that the trace was stopped
2543 with a command. The effect is similar to setting the variable
2546 * Tracepoints can now be enabled and disabled at any time after a trace
2547 experiment has been started using the standard "enable" and "disable"
2548 commands. It is now possible to start a trace experiment with no enabled
2549 tracepoints; GDB will display a warning, but will allow the experiment to
2550 begin, assuming that tracepoints will be enabled as needed while the trace
2553 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2554 locations with 4-byte instructions, when they were previously
2555 limited to locations with instructions of 5 bytes or longer.
2559 set debug dwarf2-read
2560 show debug dwarf2-read
2561 Turns on or off display of debugging messages related to reading
2562 DWARF debug info. The default is off.
2564 set debug symtab-create
2565 show debug symtab-create
2566 Turns on or off display of debugging messages related to symbol table
2567 creation. The default is off.
2570 show extended-prompt
2571 Set the GDB prompt, and allow escape sequences to be inserted to
2572 display miscellaneous information (see 'help set extended-prompt'
2573 for the list of sequences). This prompt (and any information
2574 accessed through the escape sequences) is updated every time the
2575 prompt is displayed.
2577 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2578 show print entry-values
2579 Set printing of frame argument values at function entry. In some cases
2580 GDB can determine the value of function argument which was passed by the
2581 function caller, even if the value was modified inside the called function.
2583 set debug entry-values
2584 show debug entry-values
2585 Control display of debugging info for determining frame argument values at
2586 function entry and virtual tail call frames.
2588 set basenames-may-differ
2589 show basenames-may-differ
2590 Set whether a source file may have multiple base names.
2591 (A "base name" is the name of a file with the directory part removed.
2592 Example: The base name of "/home/user/hello.c" is "hello.c".)
2593 If set, GDB will canonicalize file names (e.g., expand symlinks)
2594 before comparing them. Canonicalization is an expensive operation,
2595 but it allows the same file be known by more than one base name.
2596 If not set (the default), all source files are assumed to have just
2597 one base name, and gdb will do file name comparisons more efficiently.
2603 Set a user name and notes for the current and any future trace runs.
2604 This is useful for long-running and/or disconnected traces, to
2605 inform others (or yourself) as to who is running the trace, supply
2606 contact information, or otherwise explain what is going on.
2608 set trace-stop-notes
2609 show trace-stop-notes
2610 Set a note attached to the trace run, that is displayed when the
2611 trace has been stopped by a tstop command. This is useful for
2612 instance as an explanation, if you are stopping a trace run that was
2613 started by someone else.
2615 * New remote packets
2619 Dynamically enable a tracepoint in a started trace experiment.
2623 Dynamically disable a tracepoint in a started trace experiment.
2627 Set the user and notes of the trace run.
2631 Query the current status of a tracepoint.
2635 Query the minimum length of instruction at which a fast tracepoint may
2638 * Dcache size (number of lines) and line-size are now runtime-configurable
2639 via "set dcache line" and "set dcache line-size" commands.
2643 Texas Instruments TMS320C6x tic6x-*-*
2647 Renesas RL78 rl78-*-elf
2649 *** Changes in GDB 7.3.1
2651 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2653 *** Changes in GDB 7.3
2655 * GDB has a new command: "thread find [REGEXP]".
2656 It finds the thread id whose name, target id, or thread extra info
2657 matches the given regular expression.
2659 * The "catch syscall" command now works on mips*-linux* targets.
2661 * The -data-disassemble MI command now supports modes 2 and 3 for
2662 dumping the instruction opcodes.
2664 * New command line options
2666 -data-directory DIR Specify DIR as the "data-directory".
2667 This is mostly for testing purposes.
2669 * The "maint set python auto-load on|off" command has been renamed to
2670 "set auto-load-scripts on|off".
2672 * GDB has a new command: "set directories".
2673 It is like the "dir" command except that it replaces the
2674 source path list instead of augmenting it.
2676 * GDB now understands thread names.
2678 On GNU/Linux, "info threads" will display the thread name as set by
2679 prctl or pthread_setname_np.
2681 There is also a new command, "thread name", which can be used to
2682 assign a name internally for GDB to display.
2685 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2686 has been integrated into GDB.
2690 ** The function gdb.Write now accepts an optional keyword 'stream'.
2691 This keyword, when provided, will direct the output to either
2692 stdout, stderr, or GDB's logging output.
2694 ** Parameters can now be be sub-classed in Python, and in particular
2695 you may implement the get_set_doc and get_show_doc functions.
2696 This improves how Parameter set/show documentation is processed
2697 and allows for more dynamic content.
2699 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2700 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2701 have an is_valid method.
2703 ** Breakpoints can now be sub-classed in Python, and in particular
2704 you may implement a 'stop' function that is executed each time
2705 the inferior reaches that breakpoint.
2707 ** New function gdb.lookup_global_symbol looks up a global symbol.
2709 ** GDB values in Python are now callable if the value represents a
2710 function. For example, if 'some_value' represents a function that
2711 takes two integer parameters and returns a value, you can call
2712 that function like so:
2714 result = some_value (10,20)
2716 ** Module gdb.types has been added.
2717 It contains a collection of utilities for working with gdb.Types objects:
2718 get_basic_type, has_field, make_enum_dict.
2720 ** Module gdb.printing has been added.
2721 It contains utilities for writing and registering pretty-printers.
2722 New classes: PrettyPrinter, SubPrettyPrinter,
2723 RegexpCollectionPrettyPrinter.
2724 New function: register_pretty_printer.
2726 ** New commands "info pretty-printers", "enable pretty-printer" and
2727 "disable pretty-printer" have been added.
2729 ** gdb.parameter("directories") is now available.
2731 ** New function gdb.newest_frame returns the newest frame in the
2734 ** The gdb.InferiorThread class has a new "name" attribute. This
2735 holds the thread's name.
2737 ** Python Support for Inferior events.
2738 Python scripts can add observers to be notified of events
2739 occurring in the process being debugged.
2740 The following events are currently supported:
2741 - gdb.events.cont Continue event.
2742 - gdb.events.exited Inferior exited event.
2743 - gdb.events.stop Signal received, and Breakpoint hit events.
2747 ** GDB now puts template parameters in scope when debugging in an
2748 instantiation. For example, if you have:
2750 template<int X> int func (void) { return X; }
2752 then if you step into func<5>, "print X" will show "5". This
2753 feature requires proper debuginfo support from the compiler; it
2754 was added to GCC 4.5.
2756 ** The motion commands "next", "finish", "until", and "advance" now
2757 work better when exceptions are thrown. In particular, GDB will
2758 no longer lose control of the inferior; instead, the GDB will
2759 stop the inferior at the point at which the exception is caught.
2760 This functionality requires a change in the exception handling
2761 code that was introduced in GCC 4.5.
2763 * GDB now follows GCC's rules on accessing volatile objects when
2764 reading or writing target state during expression evaluation.
2765 One notable difference to prior behavior is that "print x = 0"
2766 no longer generates a read of x; the value of the assignment is
2767 now always taken directly from the value being assigned.
2769 * GDB now has some support for using labels in the program's source in
2770 linespecs. For instance, you can use "advance label" to continue
2771 execution to a label.
2773 * GDB now has support for reading and writing a new .gdb_index
2774 section. This section holds a fast index of DWARF debugging
2775 information and can be used to greatly speed up GDB startup and
2776 operation. See the documentation for `save gdb-index' for details.
2778 * The "watch" command now accepts an optional "-location" argument.
2779 When used, this causes GDB to watch the memory referred to by the
2780 expression. Such a watchpoint is never deleted due to it going out
2783 * GDB now supports thread debugging of core dumps on GNU/Linux.
2785 GDB now activates thread debugging using the libthread_db library
2786 when debugging GNU/Linux core dumps, similarly to when debugging
2787 live processes. As a result, when debugging a core dump file, GDB
2788 is now able to display pthread_t ids of threads. For example, "info
2789 threads" shows the same output as when debugging the process when it
2790 was live. In earlier releases, you'd see something like this:
2793 * 1 LWP 6780 main () at main.c:10
2795 While now you see this:
2798 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2800 It is also now possible to inspect TLS variables when debugging core
2803 When debugging a core dump generated on a machine other than the one
2804 used to run GDB, you may need to point GDB at the correct
2805 libthread_db library with the "set libthread-db-search-path"
2806 command. See the user manual for more details on this command.
2808 * When natively debugging programs on PowerPC BookE processors running
2809 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2810 which stop execution of the inferior whenever it executes an instruction
2811 at any address within the specified range. See the "PowerPC Embedded"
2812 section in the user manual for more details.
2814 * New features in the GDB remote stub, GDBserver
2816 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2817 and i686 LynxOS (version 5.x).
2819 ** GDBserver is now supported on Blackfin Linux.
2821 * New native configurations
2823 ia64 HP-UX ia64-*-hpux*
2827 Analog Devices, Inc. Blackfin Processor bfin-*
2829 * Ada task switching is now supported on sparc-elf targets when
2830 debugging a program using the Ravenscar Profile. For more information,
2831 see the "Tasking Support when using the Ravenscar Profile" section
2832 in the GDB user manual.
2834 * Guile support was removed.
2836 * New features in the GNU simulator
2838 ** The --map-info flag lists all known core mappings.
2840 ** CFI flashes may be simulated via the "cfi" device.
2842 *** Changes in GDB 7.2
2844 * Shared library support for remote targets by default
2846 When GDB is configured for a generic, non-OS specific target, like
2847 for example, --target=arm-eabi or one of the many *-*-elf targets,
2848 GDB now queries remote stubs for loaded shared libraries using the
2849 `qXfer:libraries:read' packet. Previously, shared library support
2850 was always disabled for such configurations.
2854 ** Argument Dependent Lookup (ADL)
2856 In C++ ADL lookup directs function search to the namespaces of its
2857 arguments even if the namespace has not been imported.
2867 Here the compiler will search for `foo' in the namespace of 'b'
2868 and find A::foo. GDB now supports this. This construct is commonly
2869 used in the Standard Template Library for operators.
2871 ** Improved User Defined Operator Support
2873 In addition to member operators, GDB now supports lookup of operators
2874 defined in a namespace and imported with a `using' directive, operators
2875 defined in the global scope, operators imported implicitly from an
2876 anonymous namespace, and the ADL operators mentioned in the previous
2878 GDB now also supports proper overload resolution for all the previously
2879 mentioned flavors of operators.
2881 ** static const class members
2883 Printing of static const class members that are initialized in the
2884 class definition has been fixed.
2886 * Windows Thread Information Block access.
2888 On Windows targets, GDB now supports displaying the Windows Thread
2889 Information Block (TIB) structure. This structure is visible either
2890 by using the new command `info w32 thread-information-block' or, by
2891 dereferencing the new convenience variable named `$_tlb', a
2892 thread-specific pointer to the TIB. This feature is also supported
2893 when remote debugging using GDBserver.
2895 * Static tracepoints
2897 Static tracepoints are calls in the user program into a tracing
2898 library. One such library is a port of the LTTng kernel tracer to
2899 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2900 When debugging with GDBserver, GDB now supports combining the GDB
2901 tracepoint machinery with such libraries. For example: the user can
2902 use GDB to probe a static tracepoint marker (a call from the user
2903 program into the tracing library) with the new "strace" command (see
2904 "New commands" below). This creates a "static tracepoint" in the
2905 breakpoint list, that can be manipulated with the same feature set
2906 as fast and regular tracepoints. E.g., collect registers, local and
2907 global variables, collect trace state variables, and define
2908 tracepoint conditions. In addition, the user can collect extra
2909 static tracepoint marker specific data, by collecting the new
2910 $_sdata internal variable. When analyzing the trace buffer, you can
2911 inspect $_sdata like any other variable available to GDB. For more
2912 information, see the "Tracepoints" chapter in GDB user manual. New
2913 remote packets have been defined to support static tracepoints, see
2914 the "New remote packets" section below.
2916 * Better reconstruction of tracepoints after disconnected tracing
2918 GDB will attempt to download the original source form of tracepoint
2919 definitions when starting a trace run, and then will upload these
2920 upon reconnection to the target, resulting in a more accurate
2921 reconstruction of the tracepoints that are in use on the target.
2925 You can now exercise direct control over the ways that GDB can
2926 affect your program. For instance, you can disallow the setting of
2927 breakpoints, so that the program can run continuously (assuming
2928 non-stop mode). In addition, the "observer" variable is available
2929 to switch all of the different controls; in observer mode, GDB
2930 cannot affect the target's behavior at all, which is useful for
2931 tasks like diagnosing live systems in the field.
2933 * The new convenience variable $_thread holds the number of the
2936 * New remote packets
2940 Return the address of the Windows Thread Information Block of a given thread.
2944 In response to several of the tracepoint packets, the target may now
2945 also respond with a number of intermediate `qRelocInsn' request
2946 packets before the final result packet, to have GDB handle
2947 relocating an instruction to execute at a different address. This
2948 is particularly useful for stubs that support fast tracepoints. GDB
2949 reports support for this feature in the qSupported packet.
2953 List static tracepoint markers in the target program.
2957 List static tracepoint markers at a given address in the target
2960 qXfer:statictrace:read
2962 Read the static trace data collected (by a `collect $_sdata'
2963 tracepoint action). The remote stub reports support for this packet
2964 to gdb's qSupported query.
2968 Send the current settings of GDB's permission flags.
2972 Send part of the source (textual) form of a tracepoint definition,
2973 which includes location, conditional, and action list.
2975 * The source command now accepts a -s option to force searching for the
2976 script in the source search path even if the script name specifies
2979 * New features in the GDB remote stub, GDBserver
2981 - GDBserver now support tracepoints (including fast tracepoints, and
2982 static tracepoints). The feature is currently supported by the
2983 i386-linux and amd64-linux builds. See the "Tracepoints support
2984 in gdbserver" section in the manual for more information.
2986 GDBserver JIT compiles the tracepoint's conditional agent
2987 expression bytecode into native code whenever possible for low
2988 overhead dynamic tracepoints conditionals. For such tracepoints,
2989 an expression that examines program state is evaluated when the
2990 tracepoint is reached, in order to determine whether to capture
2991 trace data. If the condition is simple and false, processing the
2992 tracepoint finishes very quickly and no data is gathered.
2994 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2995 for static tracepoints support.
2997 - GDBserver now supports x86_64 Windows 64-bit debugging.
2999 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3000 it understands register description.
3002 * The --batch flag now disables pagination and queries.
3004 * X86 general purpose registers
3006 GDB now supports reading/writing byte, word and double-word x86
3007 general purpose registers directly. This means you can use, say,
3008 $ah or $ax to refer, respectively, to the byte register AH and
3009 16-bit word register AX that are actually portions of the 32-bit
3010 register EAX or 64-bit register RAX.
3012 * The `commands' command now accepts a range of breakpoints to modify.
3013 A plain `commands' following a command that creates multiple
3014 breakpoints affects all the breakpoints set by that command. This
3015 applies to breakpoints set by `rbreak', and also applies when a
3016 single `break' command creates multiple breakpoints (e.g.,
3017 breakpoints on overloaded c++ functions).
3019 * The `rbreak' command now accepts a filename specification as part of
3020 its argument, limiting the functions selected by the regex to those
3021 in the specified file.
3023 * Support for remote debugging Windows and SymbianOS shared libraries
3024 from Unix hosts has been improved. Non Windows GDB builds now can
3025 understand target reported file names that follow MS-DOS based file
3026 system semantics, such as file names that include drive letters and
3027 use the backslash character as directory separator. This makes it
3028 possible to transparently use the "set sysroot" and "set
3029 solib-search-path" on Unix hosts to point as host copies of the
3030 target's shared libraries. See the new command "set
3031 target-file-system-kind" described below, and the "Commands to
3032 specify files" section in the user manual for more information.
3036 eval template, expressions...
3037 Convert the values of one or more expressions under the control
3038 of the string template to a command line, and call it.
3040 set target-file-system-kind unix|dos-based|auto
3041 show target-file-system-kind
3042 Set or show the assumed file system kind for target reported file
3045 save breakpoints <filename>
3046 Save all current breakpoint definitions to a file suitable for use
3047 in a later debugging session. To read the saved breakpoint
3048 definitions, use the `source' command.
3050 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3053 info static-tracepoint-markers
3054 Display information about static tracepoint markers in the target.
3056 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3057 Define a static tracepoint by probing a marker at the given
3058 function, line, address, or marker ID.
3062 Enable and disable observer mode.
3064 set may-write-registers on|off
3065 set may-write-memory on|off
3066 set may-insert-breakpoints on|off
3067 set may-insert-tracepoints on|off
3068 set may-insert-fast-tracepoints on|off
3069 set may-interrupt on|off
3070 Set individual permissions for GDB effects on the target. Note that
3071 some of these settings can have undesirable or surprising
3072 consequences, particularly when changed in the middle of a session.
3073 For instance, disabling the writing of memory can prevent
3074 breakpoints from being inserted, cause single-stepping to fail, or
3075 even crash your program, if you disable after breakpoints have been
3076 inserted. However, GDB should not crash.
3078 set record memory-query on|off
3079 show record memory-query
3080 Control whether to stop the inferior if memory changes caused
3081 by an instruction cannot be recorded.
3086 The disassemble command now supports "start,+length" form of two arguments.
3090 ** GDB now provides a new directory location, called the python directory,
3091 where Python scripts written for GDB can be installed. The location
3092 of that directory is <data-directory>/python, where <data-directory>
3093 is the GDB data directory. For more details, see section `Scripting
3094 GDB using Python' in the manual.
3096 ** The GDB Python API now has access to breakpoints, symbols, symbol
3097 tables, program spaces, inferiors, threads and frame's code blocks.
3098 Additionally, GDB Parameters can now be created from the API, and
3099 manipulated via set/show in the CLI.
3101 ** New functions gdb.target_charset, gdb.target_wide_charset,
3102 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3104 ** New exception gdb.GdbError.
3106 ** Pretty-printers are now also looked up in the current program space.
3108 ** Pretty-printers can now be individually enabled and disabled.
3110 ** GDB now looks for names of Python scripts to auto-load in a
3111 special section named `.debug_gdb_scripts', in addition to looking
3112 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3114 * Tracepoint actions were unified with breakpoint commands. In particular,
3115 there are no longer differences in "info break" output for breakpoints and
3116 tracepoints and the "commands" command can be used for both tracepoints and
3117 regular breakpoints.
3121 ARM Symbian arm*-*-symbianelf*
3123 * D language support.
3124 GDB now supports debugging programs written in the D programming
3127 * GDB now supports the extended ptrace interface for PowerPC which is
3128 available since Linux kernel version 2.6.34. This automatically enables
3129 any hardware breakpoints and additional hardware watchpoints available in
3130 the processor. The old ptrace interface exposes just one hardware
3131 watchpoint and no hardware breakpoints.
3133 * GDB is now able to use the Data Value Compare (DVC) register available on
3134 embedded PowerPC processors to implement in hardware simple watchpoint
3135 conditions of the form:
3137 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3139 This works in native GDB running on Linux kernels with the extended ptrace
3140 interface mentioned above.
3142 *** Changes in GDB 7.1
3146 ** Namespace Support
3148 GDB now supports importing of namespaces in C++. This enables the
3149 user to inspect variables from imported namespaces. Support for
3150 namepace aliasing has also been added. So, if a namespace is
3151 aliased in the current scope (e.g. namepace C=A; ) the user can
3152 print variables using the alias (e.g. (gdb) print C::x).
3156 All known bugs relating to the printing of virtual base class were
3157 fixed. It is now possible to call overloaded static methods using a
3162 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3163 and reinterpret_cast<> are now handled by the C++ expression parser.
3167 Xilinx MicroBlaze microblaze-*-*
3172 Xilinx MicroBlaze microblaze
3175 * Multi-program debugging.
3177 GDB now has support for multi-program (a.k.a. multi-executable or
3178 multi-exec) debugging. This allows for debugging multiple inferiors
3179 simultaneously each running a different program under the same GDB
3180 session. See "Debugging Multiple Inferiors and Programs" in the
3181 manual for more information. This implied some user visible changes
3182 in the multi-inferior support. For example, "info inferiors" now
3183 lists inferiors that are not running yet or that have exited
3184 already. See also "New commands" and "New options" below.
3186 * New tracing features
3188 GDB's tracepoint facility now includes several new features:
3190 ** Trace state variables
3192 GDB tracepoints now include support for trace state variables, which
3193 are variables managed by the target agent during a tracing
3194 experiment. They are useful for tracepoints that trigger each
3195 other, so for instance one tracepoint can count hits in a variable,
3196 and then a second tracepoint has a condition that is true when the
3197 count reaches a particular value. Trace state variables share the
3198 $-syntax of GDB convenience variables, and can appear in both
3199 tracepoint actions and condition expressions. Use the "tvariable"
3200 command to create, and "info tvariables" to view; see "Trace State
3201 Variables" in the manual for more detail.
3205 GDB now includes an option for defining fast tracepoints, which
3206 targets may implement more efficiently, such as by installing a jump
3207 into the target agent rather than a trap instruction. The resulting
3208 speedup can be by two orders of magnitude or more, although the
3209 tradeoff is that some program locations on some target architectures
3210 might not allow fast tracepoint installation, for instance if the
3211 instruction to be replaced is shorter than the jump. To request a
3212 fast tracepoint, use the "ftrace" command, with syntax identical to
3213 the regular trace command.
3215 ** Disconnected tracing
3217 It is now possible to detach GDB from the target while it is running
3218 a trace experiment, then reconnect later to see how the experiment
3219 is going. In addition, a new variable disconnected-tracing lets you
3220 tell the target agent whether to continue running a trace if the
3221 connection is lost unexpectedly.
3225 GDB now has the ability to save the trace buffer into a file, and
3226 then use that file as a target, similarly to you can do with
3227 corefiles. You can select trace frames, print data that was
3228 collected in them, and use tstatus to display the state of the
3229 tracing run at the moment that it was saved. To create a trace
3230 file, use "tsave <filename>", and to use it, do "target tfile
3233 ** Circular trace buffer
3235 You can ask the target agent to handle the trace buffer as a
3236 circular buffer, discarding the oldest trace frames to make room for
3237 newer ones, by setting circular-trace-buffer to on. This feature may
3238 not be available for all target agents.
3243 The disassemble command, when invoked with two arguments, now requires
3244 the arguments to be comma-separated.
3247 The info variables command now displays variable definitions. Files
3248 which only declare a variable are not shown.
3251 The source command is now capable of sourcing Python scripts.
3252 This feature is dependent on the debugger being build with Python
3255 Related to this enhancement is also the introduction of a new command
3256 "set script-extension" (see below).
3258 * New commands (for set/show, see "New options" below)
3260 record save [<FILENAME>]
3261 Save a file (in core file format) containing the process record
3262 execution log for replay debugging at a later time.
3264 record restore <FILENAME>
3265 Restore the process record execution log that was saved at an
3266 earlier time, for replay debugging.
3268 add-inferior [-copies <N>] [-exec <FILENAME>]
3271 clone-inferior [-copies <N>] [ID]
3272 Make a new inferior ready to execute the same program another
3273 inferior has loaded.
3278 maint info program-spaces
3279 List the program spaces loaded into GDB.
3281 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3282 show remote interrupt-sequence
3283 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3284 as the sequence to the remote target in order to interrupt the execution.
3285 Ctrl-C is a default. Some system prefers BREAK which is high level of
3286 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3287 Magic SysRq g. It is BREAK signal and character 'g'.
3289 set remote interrupt-on-connect [on | off]
3290 show remote interrupt-on-connect
3291 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3292 remote target when gdb connects to it. This is needed when you debug
3295 set remotebreak [on | off]
3297 Deprecated. Use "set/show remote interrupt-sequence" instead.
3299 tvariable $NAME [ = EXP ]
3300 Create or modify a trace state variable.
3303 List trace state variables and their values.
3305 delete tvariable $NAME ...
3306 Delete one or more trace state variables.
3309 Evaluate the given expressions without collecting anything into the
3310 trace buffer. (Valid in tracepoint actions only.)
3312 ftrace FN / FILE:LINE / *ADDR
3313 Define a fast tracepoint at the given function, line, or address.
3315 * New expression syntax
3317 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3318 GDB now parses 0b101010 identically with 42.
3322 set follow-exec-mode new|same
3323 show follow-exec-mode
3324 Control whether GDB reuses the same inferior across an exec call or
3325 creates a new one. This is useful to be able to restart the old
3326 executable after the inferior having done an exec call.
3328 set default-collect EXPR, ...
3329 show default-collect
3330 Define a list of expressions to be collected at each tracepoint.
3331 This is a useful way to ensure essential items are not overlooked,
3332 such as registers or a critical global variable.
3334 set disconnected-tracing
3335 show disconnected-tracing
3336 If set to 1, the target is instructed to continue tracing if it
3337 loses its connection to GDB. If 0, the target is to stop tracing
3340 set circular-trace-buffer
3341 show circular-trace-buffer
3342 If set to on, the target is instructed to use a circular trace buffer
3343 and discard the oldest trace frames instead of stopping the trace due
3344 to a full trace buffer. If set to off, the trace stops when the buffer
3345 fills up. Some targets may not support this.
3347 set script-extension off|soft|strict
3348 show script-extension
3349 If set to "off", the debugger does not perform any script language
3350 recognition, and all sourced files are assumed to be GDB scripts.
3351 If set to "soft" (the default), files are sourced according to
3352 filename extension, falling back to GDB scripts if the first
3354 If set to "strict", files are sourced according to filename extension.
3356 set ada trust-PAD-over-XVS on|off
3357 show ada trust-PAD-over-XVS
3358 If off, activate a workaround against a bug in the debugging information
3359 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3360 the GCC sources for more information about the GNAT encoding and
3361 PAD types in particular). It is always safe to set this option to
3362 off, but this introduces a slight performance penalty. The default
3365 * Python API Improvements
3367 ** GDB provides the new class gdb.LazyString. This is useful in
3368 some pretty-printing cases. The new method gdb.Value.lazy_string
3369 provides a simple way to create objects of this type.
3371 ** The fields returned by gdb.Type.fields now have an
3372 `is_base_class' attribute.
3374 ** The new method gdb.Type.range returns the range of an array type.
3376 ** The new method gdb.parse_and_eval can be used to parse and
3377 evaluate an expression.
3379 * New remote packets
3382 Define a trace state variable.
3385 Get the current value of a trace state variable.
3388 Set desired tracing behavior upon disconnection.
3391 Set the trace buffer to be linear or circular.
3394 Get data about the tracepoints currently in use.
3398 Process record now works correctly with hardware watchpoints.
3400 Multiple bug fixes have been made to the mips-irix port, making it
3401 much more reliable. In particular:
3402 - Debugging threaded applications is now possible again. Previously,
3403 GDB would hang while starting the program, or while waiting for
3404 the program to stop at a breakpoint.
3405 - Attaching to a running process no longer hangs.
3406 - An error occurring while loading a core file has been fixed.
3407 - Changing the value of the PC register now works again. This fixes
3408 problems observed when using the "jump" command, or when calling
3409 a function from GDB, or even when assigning a new value to $pc.
3410 - With the "finish" and "return" commands, the return value for functions
3411 returning a small array is now correctly printed.
3412 - It is now possible to break on shared library code which gets executed
3413 during a shared library init phase (code executed while executing
3414 their .init section). Previously, the breakpoint would have no effect.
3415 - GDB is now able to backtrace through the signal handler for
3416 non-threaded programs.
3418 PIE (Position Independent Executable) programs debugging is now supported.
3419 This includes debugging execution of PIC (Position Independent Code) shared
3420 libraries although for that, it should be possible to run such libraries as an
3423 *** Changes in GDB 7.0
3425 * GDB now has an interface for JIT compilation. Applications that
3426 dynamically generate code can create symbol files in memory and register
3427 them with GDB. For users, the feature should work transparently, and
3428 for JIT developers, the interface is documented in the GDB manual in the
3429 "JIT Compilation Interface" chapter.
3431 * Tracepoints may now be conditional. The syntax is as for
3432 breakpoints; either an "if" clause appended to the "trace" command,
3433 or the "condition" command is available. GDB sends the condition to
3434 the target for evaluation using the same bytecode format as is used
3435 for tracepoint actions.
3437 * The disassemble command now supports: an optional /r modifier, print the
3438 raw instructions in hex as well as in symbolic form, and an optional /m
3439 modifier to print mixed source+assembly.
3441 * Process record and replay
3443 In a architecture environment that supports ``process record and
3444 replay'', ``process record and replay'' target can record a log of
3445 the process execution, and replay it with both forward and reverse
3448 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3449 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3450 set execution-direction {forward|reverse}, for targets that support
3453 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3454 feature is available with a native GDB running on kernel version
3457 * GDB now has support for multi-byte and wide character sets on the
3458 target. Strings whose character type is wchar_t, char16_t, or
3459 char32_t are now correctly printed. GDB supports wide- and unicode-
3460 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3461 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3462 `printf'. This feature requires iconv to work properly; if your
3463 system does not have a working iconv, GDB can use GNU libiconv. See
3464 the installation instructions for more information.
3466 * GDB now supports automatic retrieval of shared library files from
3467 remote targets. To use this feature, specify a system root that begins
3468 with the `remote:' prefix, either via the `set sysroot' command or via
3469 the `--with-sysroot' configure-time option.
3471 * "info sharedlibrary" now takes an optional regex of libraries to show,
3472 and it now reports if a shared library has no debugging information.
3474 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3475 now complete on file names.
3477 * When completing in expressions, gdb will attempt to limit
3478 completions to allowable structure or union fields, where appropriate.
3479 For instance, consider:
3481 # struct example { int f1; double f2; };
3482 # struct example variable;
3485 If the user types TAB at the end of this command line, the available
3486 completions will be "f1" and "f2".
3488 * Inlined functions are now supported. They show up in backtraces, and
3489 the "step", "next", and "finish" commands handle them automatically.
3491 * GDB now supports the token-splicing (##) and stringification (#)
3492 operators when expanding macros. It also supports variable-arity
3495 * GDB now supports inspecting extra signal information, exported by
3496 the new $_siginfo convenience variable. The feature is currently
3497 implemented on linux ARM, i386 and amd64.
3499 * GDB can now display the VFP floating point registers and NEON vector
3500 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3501 can provide these registers (requires Linux 2.6.30 or later). Remote
3502 and simulator targets may also provide them.
3504 * New remote packets
3507 Search memory for a sequence of bytes.
3510 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3511 operation over reliable transport links. Use of this packet is
3512 controlled by the `set remote noack-packet' command.
3515 Kill the process with the specified process ID. Use this in preference
3516 to `k' when multiprocess protocol extensions are supported.
3519 Obtains additional operating system information
3523 Read or write additional signal information.
3525 * Removed remote protocol undocumented extension
3527 An undocumented extension to the remote protocol's `S' stop reply
3528 packet that permited the stub to pass a process id was removed.
3529 Remote servers should use the `T' stop reply packet instead.
3531 * GDB now supports multiple function calling conventions according to the
3532 DWARF-2 DW_AT_calling_convention function attribute.
3534 * The SH target utilizes the aforementioned change to distinguish between gcc
3535 and Renesas calling convention. It also adds the new CLI commands
3536 `set/show sh calling-convention'.
3538 * GDB can now read compressed debug sections, as produced by GNU gold
3539 with the --compress-debug-sections=zlib flag.
3541 * 64-bit core files are now supported on AIX.
3543 * Thread switching is now supported on Tru64.
3545 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3546 which will be allocated using malloc later in program execution.
3548 * The qXfer:libraries:read remote procotol packet now allows passing a
3549 list of section offsets.
3551 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3552 conditions handling signals delivered during attach or thread creation
3553 have also been fixed.
3555 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3556 From the user's standpoint, all unqualified instances of True and False
3557 are treated as the standard definitions, regardless of context.
3559 * GDB now parses C++ symbol and type names more flexibly. For
3562 template<typename T> class C { };
3565 GDB will now correctly handle all of:
3567 ptype C<char const *>
3568 ptype C<char const*>
3569 ptype C<const char *>
3570 ptype C<const char*>
3572 * New features in the GDB remote stub, gdbserver
3574 - The "--wrapper" command-line argument tells gdbserver to use a
3575 wrapper program to launch programs for debugging.
3577 - On PowerPC and S/390 targets, it is now possible to use a single
3578 gdbserver executable to debug both 32-bit and 64-bit programs.
3579 (This requires gdbserver itself to be built as a 64-bit executable.)
3581 - gdbserver uses the new noack protocol mode for TCP connections to
3582 reduce communications latency, if also supported and enabled in GDB.
3584 - Support for the sparc64-linux-gnu target is now included in
3587 - The amd64-linux build of gdbserver now supports debugging both
3588 32-bit and 64-bit programs.
3590 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3591 now support hardware watchpoints, and will use them automatically
3596 GDB now has support for scripting using Python. Whether this is
3597 available is determined at configure time.
3599 New GDB commands can now be written in Python.
3601 * Ada tasking support
3603 Ada tasks can now be inspected in GDB. The following commands have
3607 Print the list of Ada tasks.
3609 Print detailed information about task number N.
3611 Print the task number of the current task.
3613 Switch the context of debugging to task number N.
3615 * Support for user-defined prefixed commands. The "define" command can
3616 add new commands to existing prefixes, e.g. "target".
3618 * Multi-inferior, multi-process debugging.
3620 GDB now has generalized support for multi-inferior debugging. See
3621 "Debugging Multiple Inferiors" in the manual for more information.
3622 Although availability still depends on target support, the command
3623 set is more uniform now. The GNU/Linux specific multi-forks support
3624 has been migrated to this new framework. This implied some user
3625 visible changes; see "New commands" and also "Removed commands"
3628 * Target descriptions can now describe the target OS ABI. See the
3629 "Target Description Format" section in the user manual for more
3632 * Target descriptions can now describe "compatible" architectures
3633 to indicate that the target can execute applications for a different
3634 architecture in addition to those for the main target architecture.
3635 See the "Target Description Format" section in the user manual for
3638 * Multi-architecture debugging.
3640 GDB now includes general supports for debugging applications on
3641 hybrid systems that use more than one single processor architecture
3642 at the same time. Each such hybrid architecture still requires
3643 specific support to be added. The only hybrid architecture supported
3644 in this version of GDB is the Cell Broadband Engine.
3646 * GDB now supports integrated debugging of Cell/B.E. applications that
3647 use both the PPU and SPU architectures. To enable support for hybrid
3648 Cell/B.E. debugging, you need to configure GDB to support both the
3649 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3650 --enable-targets configure option.
3652 * Non-stop mode debugging.
3654 For some targets, GDB now supports an optional mode of operation in
3655 which you can examine stopped threads while other threads continue
3656 to execute freely. This is referred to as non-stop mode, with the
3657 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3658 section in the user manual for more information.
3660 To be able to support remote non-stop debugging, a remote stub needs
3661 to implement the non-stop mode remote protocol extensions, as
3662 described in the "Remote Non-Stop" section of the user manual. The
3663 GDB remote stub, gdbserver, has been adjusted to support these
3664 extensions on linux targets.
3666 * New commands (for set/show, see "New options" below)
3668 catch syscall [NAME(S) | NUMBER(S)]
3669 Catch system calls. Arguments, which should be names of system
3670 calls or their numbers, mean catch only those syscalls. Without
3671 arguments, every syscall will be caught. When the inferior issues
3672 any of the specified syscalls, GDB will stop and announce the system
3673 call, both when it is called and when its call returns. This
3674 feature is currently available with a native GDB running on the
3675 Linux Kernel, under the following architectures: x86, x86_64,
3676 PowerPC and PowerPC64.
3678 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3680 Search memory for a sequence of bytes.
3682 maint set python print-stack
3683 maint show python print-stack
3684 Show a stack trace when an error is encountered in a Python script.
3687 Invoke CODE by passing it to the Python interpreter.
3692 These allow macros to be defined, undefined, and listed
3696 Show operating system information about processes.
3699 List the inferiors currently under GDB's control.
3702 Switch focus to inferior number NUM.
3705 Detach from inferior number NUM.
3708 Kill inferior number NUM.
3712 set spu stop-on-load
3713 show spu stop-on-load
3714 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3716 set spu auto-flush-cache
3717 show spu auto-flush-cache
3718 Control whether to automatically flush the software-managed cache
3719 during Cell/B.E. debugging.
3721 set sh calling-convention
3722 show sh calling-convention
3723 Control the calling convention used when calling SH target functions.
3726 show debug timestamp
3727 Control display of timestamps with GDB debugging output.
3729 set disassemble-next-line
3730 show disassemble-next-line
3731 Control display of disassembled source lines or instructions when
3734 set remote noack-packet
3735 show remote noack-packet
3736 Set/show the use of remote protocol QStartNoAckMode packet. See above
3737 under "New remote packets."
3739 set remote query-attached-packet
3740 show remote query-attached-packet
3741 Control use of remote protocol `qAttached' (query-attached) packet.
3743 set remote read-siginfo-object
3744 show remote read-siginfo-object
3745 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3748 set remote write-siginfo-object
3749 show remote write-siginfo-object
3750 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3753 set remote reverse-continue
3754 show remote reverse-continue
3755 Control use of remote protocol 'bc' (reverse-continue) packet.
3757 set remote reverse-step
3758 show remote reverse-step
3759 Control use of remote protocol 'bs' (reverse-step) packet.
3761 set displaced-stepping
3762 show displaced-stepping
3763 Control displaced stepping mode. Displaced stepping is a way to
3764 single-step over breakpoints without removing them from the debuggee.
3765 Also known as "out-of-line single-stepping".
3768 show debug displaced
3769 Control display of debugging info for displaced stepping.
3771 maint set internal-error
3772 maint show internal-error
3773 Control what GDB does when an internal error is detected.
3775 maint set internal-warning
3776 maint show internal-warning
3777 Control what GDB does when an internal warning is detected.
3782 Use a wrapper program to launch programs for debugging.
3784 set multiple-symbols (all|ask|cancel)
3785 show multiple-symbols
3786 The value of this variable can be changed to adjust the debugger behavior
3787 when an expression or a breakpoint location contains an ambiguous symbol
3788 name (an overloaded function name, for instance).
3790 set breakpoint always-inserted
3791 show breakpoint always-inserted
3792 Keep breakpoints always inserted in the target, as opposed to inserting
3793 them when resuming the target, and removing them when the target stops.
3794 This option can improve debugger performance on slow remote targets.
3796 set arm fallback-mode (arm|thumb|auto)
3797 show arm fallback-mode
3798 set arm force-mode (arm|thumb|auto)
3800 These commands control how ARM GDB determines whether instructions
3801 are ARM or Thumb. The default for both settings is auto, which uses
3802 the current CPSR value for instructions without symbols; previous
3803 versions of GDB behaved as if "set arm fallback-mode arm".
3805 set disable-randomization
3806 show disable-randomization
3807 Standalone programs run with the virtual address space randomization enabled
3808 by default on some platforms. This option keeps the addresses stable across
3809 multiple debugging sessions.
3813 Control whether other threads are stopped or not when some thread hits
3818 Requests that asynchronous execution is enabled in the target, if available.
3819 In this case, it's possible to resume target in the background, and interact
3820 with GDB while the target is running. "show target-async" displays the
3821 current state of asynchronous execution of the target.
3823 set target-wide-charset
3824 show target-wide-charset
3825 The target-wide-charset is the name of the character set that GDB
3826 uses when printing characters whose type is wchar_t.
3828 set tcp auto-retry (on|off)
3830 set tcp connect-timeout
3831 show tcp connect-timeout
3832 These commands allow GDB to retry failed TCP connections to a remote stub
3833 with a specified timeout period; this is useful if the stub is launched
3834 in parallel with GDB but may not be ready to accept connections immediately.
3836 set libthread-db-search-path
3837 show libthread-db-search-path
3838 Control list of directories which GDB will search for appropriate
3841 set schedule-multiple (on|off)
3842 show schedule-multiple
3843 Allow GDB to resume all threads of all processes or only threads of
3844 the current process.
3848 Use more aggressive caching for accesses to the stack. This improves
3849 performance of remote debugging (particularly backtraces) without
3850 affecting correctness.
3852 set interactive-mode (on|off|auto)
3853 show interactive-mode
3854 Control whether GDB runs in interactive mode (on) or not (off).
3855 When in interactive mode, GDB waits for the user to answer all
3856 queries. Otherwise, GDB does not wait and assumes the default
3857 answer. When set to auto (the default), GDB determines which
3858 mode to use based on the stdin settings.
3863 For program forks, this is replaced by the new more generic `info
3864 inferiors' command. To list checkpoints, you can still use the
3865 `info checkpoints' command, which was an alias for the `info forks'
3869 Replaced by the new `inferior' command. To switch between
3870 checkpoints, you can still use the `restart' command, which was an
3871 alias for the `fork' command.
3874 This is removed, since some targets don't have a notion of
3875 processes. To switch between processes, you can still use the
3876 `inferior' command using GDB's own inferior number.
3879 For program forks, this is replaced by the new more generic `kill
3880 inferior' command. To delete a checkpoint, you can still use the
3881 `delete checkpoint' command, which was an alias for the `delete
3885 For program forks, this is replaced by the new more generic `detach
3886 inferior' command. To detach a checkpoint, you can still use the
3887 `detach checkpoint' command, which was an alias for the `detach
3890 * New native configurations
3892 x86/x86_64 Darwin i[34567]86-*-darwin*
3894 x86_64 MinGW x86_64-*-mingw*
3898 Lattice Mico32 lm32-*
3899 x86 DICOS i[34567]86-*-dicos*
3900 x86_64 DICOS x86_64-*-dicos*
3903 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3904 (mingw32ce) debugging.
3910 These commands were actually not implemented on any target.
3912 *** Changes in GDB 6.8
3914 * New native configurations
3916 NetBSD/hppa hppa*-*netbsd*
3917 Xtensa GNU/Linux xtensa*-*-linux*
3921 NetBSD/hppa hppa*-*-netbsd*
3922 Xtensa GNU/Lunux xtensa*-*-linux*
3924 * Change in command line behavior -- corefiles vs. process ids.
3926 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3927 attaching to process NUMBER fails, GDB no longer attempts to open a
3928 core file named NUMBER. Attaching to a program using the -c option
3929 is no longer supported. Instead, use the '-p' or '--pid' options.
3931 * GDB can now be built as a native debugger for debugging Windows x86
3932 (mingw32) Portable Executable (PE) programs.
3934 * Pending breakpoints no longer change their number when their address
3937 * GDB now supports breakpoints with multiple locations,
3938 including breakpoints on C++ constructors, inside C++ templates,
3939 and in inlined functions.
3941 * GDB's ability to debug optimized code has been improved. GDB more
3942 accurately identifies function bodies and lexical blocks that occupy
3943 more than one contiguous range of addresses.
3945 * Target descriptions can now describe registers for PowerPC.
3947 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3948 registers on PowerPC targets.
3950 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3951 targets even when the libthread_db library is not available.
3953 * The GDB remote stub, gdbserver, now supports the new file transfer
3954 commands (remote put, remote get, and remote delete).
3956 * The GDB remote stub, gdbserver, now supports run and attach in
3957 extended-remote mode.
3959 * hppa*64*-*-hpux11* target broken
3960 The debugger is unable to start a program and fails with the following
3961 error: "Error trying to get information about dynamic linker".
3962 The gdb-6.7 release is also affected.
3964 * GDB now supports the --enable-targets= configure option to allow
3965 building a single GDB executable that supports multiple remote
3966 target architectures.
3968 * GDB now supports debugging C and C++ programs which use the
3969 Decimal Floating Point extension. In addition, the PowerPC target
3970 now has a set of pseudo-registers to inspect decimal float values
3971 stored in two consecutive float registers.
3973 * The -break-insert MI command can optionally create pending
3976 * Improved support for debugging Ada
3977 Many improvements to the Ada language support have been made. These
3979 - Better support for Ada2005 interface types
3980 - Improved handling of arrays and slices in general
3981 - Better support for Taft-amendment types
3982 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3984 - Improved command completion in Ada
3987 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3992 set print frame-arguments (all|scalars|none)
3993 show print frame-arguments
3994 The value of this variable can be changed to control which argument
3995 values should be printed by the debugger when displaying a frame.
4000 Transfer files to and from a remote target, and delete remote files.
4007 Transfer files to and from a remote target, and delete remote files.
4009 * New remote packets
4016 Open, close, read, write, and delete files on the remote system.
4019 Attach to an existing process on the remote system, in extended-remote
4023 Run a new process on the remote system, in extended-remote mode.
4025 *** Changes in GDB 6.7
4027 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4028 bfd, libiberty and opcodes, as revealed by static analysis donated by
4029 Coverity, Inc. (http://scan.coverity.com).
4031 * When looking up multiply-defined global symbols, GDB will now prefer the
4032 symbol definition in the current shared library if it was built using the
4033 -Bsymbolic linker option.
4035 * When the Text User Interface (TUI) is not configured, GDB will now
4036 recognize the -tui command-line option and print a message that the TUI
4039 * The GDB remote stub, gdbserver, now has lower overhead for high
4040 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4042 * GDB for MIPS targets now autodetects whether a remote target provides
4043 32-bit or 64-bit register values.
4045 * Support for C++ member pointers has been improved.
4047 * GDB now understands XML target descriptions, which specify the
4048 target's overall architecture. GDB can read a description from
4049 a local file or over the remote serial protocol.
4051 * Vectors of single-byte data use a new integer type which is not
4052 automatically displayed as character or string data.
4054 * The /s format now works with the print command. It displays
4055 arrays of single-byte integers and pointers to single-byte integers
4058 * Target descriptions can now describe target-specific registers,
4059 for architectures which have implemented the support (currently
4060 only ARM, M68K, and MIPS).
4062 * GDB and the GDB remote stub, gdbserver, now support the XScale
4065 * The GDB remote stub, gdbserver, has been updated to support
4066 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4067 has been rewritten to use the standard GDB remote protocol.
4069 * GDB can now step into C++ functions which are called through thunks.
4071 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4073 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4074 layout. It also supports a TextSeg= and DataSeg= response when only
4075 segment base addresses (rather than offsets) are available.
4077 * The /i format now outputs any trailing branch delay slot instructions
4078 immediately following the last instruction within the count specified.
4080 * The GDB remote protocol "T" stop reply packet now supports a
4081 "library" response. Combined with the new "qXfer:libraries:read"
4082 packet, this response allows GDB to debug shared libraries on targets
4083 where the operating system manages the list of loaded libraries (e.g.
4084 Windows and SymbianOS).
4086 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4087 (DLLs) on Windows and Windows CE targets.
4089 * GDB now supports a faster verification that a .debug file matches its binary
4090 according to its build-id signature, if the signature is present.
4096 Enable or disable hardware flow control (RTS/CTS) on the serial port
4097 when debugging using remote targets.
4099 set mem inaccessible-by-default
4100 show mem inaccessible-by-default
4101 If the target supplies a memory map, for instance via the remote
4102 protocol's "qXfer:memory-map:read" packet, setting this variable
4103 prevents GDB from accessing memory outside the memory map. This
4104 is useful for targets with memory mapped registers or which react
4105 badly to accesses of unmapped address space.
4107 set breakpoint auto-hw
4108 show breakpoint auto-hw
4109 If the target supplies a memory map, for instance via the remote
4110 protocol's "qXfer:memory-map:read" packet, setting this variable
4111 lets GDB use hardware breakpoints automatically for memory regions
4112 where it can not use software breakpoints. This covers both the
4113 "break" command and internal breakpoints used for other commands
4114 including "next" and "finish".
4117 catch exception unhandled
4118 Stop the program execution when Ada exceptions are raised.
4121 Stop the program execution when an Ada assertion failed.
4125 Set an alternate system root for target files. This is a more
4126 general version of "set solib-absolute-prefix", which is now
4127 an alias to "set sysroot".
4130 Provide extended SPU facility status information. This set of
4131 commands is available only when debugging the Cell/B.E. SPU
4134 * New native configurations
4136 OpenBSD/sh sh*-*openbsd*
4139 unset tdesc filename
4141 Use the specified local file as an XML target description, and do
4142 not query the target for its built-in description.
4146 OpenBSD/sh sh*-*-openbsd*
4147 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4148 Toshiba Media Processor mep-elf
4150 * New remote packets
4153 Ignore the specified signals; pass them directly to the debugged program
4154 without stopping other threads or reporting them to GDB.
4156 qXfer:features:read:
4157 Read an XML target description from the target, which describes its
4162 Read or write contents of an spufs file on the target system. These
4163 packets are available only on the Cell/B.E. SPU architecture.
4165 qXfer:libraries:read:
4166 Report the loaded shared libraries. Combined with new "T" packet
4167 response, this packet allows GDB to debug shared libraries on
4168 targets where the operating system manages the list of loaded
4169 libraries (e.g. Windows and SymbianOS).
4173 Support for these obsolete configurations has been removed.
4181 i[34567]86-*-lynxos*
4182 i[34567]86-*-netware*
4183 i[34567]86-*-sco3.2v5*
4184 i[34567]86-*-sco3.2v4*
4186 i[34567]86-*-sysv4.2*
4189 i[34567]86-*-unixware2*
4190 i[34567]86-*-unixware*
4199 * Other removed features
4206 Various m68k-only ROM monitors.
4213 Various Renesas ROM monitors and debugging interfaces for SH and
4218 Support for a Macraigor serial interface to on-chip debugging.
4219 GDB does not directly support the newer parallel or USB
4224 A debug information format. The predecessor to DWARF 2 and
4225 DWARF 3, which are still supported.
4227 Support for the HP aCC compiler on HP-UX/PA-RISC
4229 SOM-encapsulated symbolic debugging information, automatic
4230 invocation of pxdb, and the aCC custom C++ ABI. This does not
4231 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4232 with aCC can still be debugged on an assembly level.
4234 MIPS ".pdr" sections
4236 A MIPS-specific format used to describe stack frame layout
4237 in debugging information.
4241 GDB could work with an older version of Guile to debug
4242 the interpreter and Scheme programs running in it.
4244 set mips stack-arg-size
4245 set mips saved-gpreg-size
4247 Use "set mips abi" to control parameter passing for MIPS.
4249 *** Changes in GDB 6.6
4254 Cell Broadband Engine SPU spu-elf
4256 * GDB can now be configured as a cross-debugger targeting native Windows
4257 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4258 running on a Windows system over TCP/IP to debug Windows programs.
4260 * The GDB remote stub, gdbserver, has been updated to support Windows and
4261 Cygwin debugging. Both single-threaded and multi-threaded programs are
4264 * The "set trust-readonly-sections" command works again. This command was
4265 broken in GDB 6.3, 6.4, and 6.5.
4267 * The "load" command now supports writing to flash memory, if the remote
4268 stub provides the required support.
4270 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4271 longer requires symbolic debug information (e.g. DWARF-2).
4276 unset substitute-path
4277 show substitute-path
4278 Manage a list of substitution rules that GDB uses to rewrite the name
4279 of the directories where the sources are located. This can be useful
4280 for instance when the sources were moved to a different location
4281 between compilation and debugging.
4285 Print each CLI command as it is executed. Each command is prefixed with
4286 a number of `+' symbols representing the nesting depth.
4287 The source command now has a `-v' option to enable the same feature.
4291 The ARM Demon monitor support (RDP protocol, "target rdp").
4293 Kernel Object Display, an embedded debugging feature which only worked with
4294 an obsolete version of Cisco IOS.
4296 The 'set download-write-size' and 'show download-write-size' commands.
4298 * New remote packets
4301 Tell a stub about GDB client features, and request remote target features.
4302 The first feature implemented is PacketSize, which allows the target to
4303 specify the size of packets it can handle - to minimize the number of
4304 packets required and improve performance when connected to a remote
4308 Fetch an OS auxilliary vector from the remote stub. This packet is a
4309 more efficient replacement for qPart:auxv:read.
4311 qXfer:memory-map:read:
4312 Fetch a memory map from the remote stub, including information about
4313 RAM, ROM, and flash memory devices.
4318 Erase and program a flash memory device.
4320 * Removed remote packets
4323 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4324 used it, and only gdbserver implemented it.
4326 *** Changes in GDB 6.5
4330 Renesas M32C/M16C m32c-elf
4332 Morpho Technologies ms1 ms1-elf
4336 init-if-undefined Initialize a convenience variable, but
4337 only if it doesn't already have a value.
4339 The following commands are presently only implemented for native GNU/Linux:
4341 checkpoint Save a snapshot of the program state.
4343 restart <n> Return the program state to a
4344 previously saved state.
4346 info checkpoints List currently saved checkpoints.
4348 delete-checkpoint <n> Delete a previously saved checkpoint.
4350 set|show detach-on-fork Tell gdb whether to detach from a newly
4351 forked process, or to keep debugging it.
4353 info forks List forks of the user program that
4354 are available to be debugged.
4356 fork <n> Switch to debugging one of several
4357 forks of the user program that are
4358 available to be debugged.
4360 delete-fork <n> Delete a fork from the list of forks
4361 that are available to be debugged (and
4362 kill the forked process).
4364 detach-fork <n> Delete a fork from the list of forks
4365 that are available to be debugged (and
4366 allow the process to continue).
4370 Morpho Technologies ms2 ms1-elf
4372 * Improved Windows host support
4374 GDB now builds as a cross debugger hosted on i686-mingw32, including
4375 native console support, and remote communications using either
4376 network sockets or serial ports.
4378 * Improved Modula-2 language support
4380 GDB can now print most types in the Modula-2 syntax. This includes:
4381 basic types, set types, record types, enumerated types, range types,
4382 pointer types and ARRAY types. Procedure var parameters are correctly
4383 printed and hexadecimal addresses and character constants are also
4384 written in the Modula-2 syntax. Best results can be obtained by using
4385 GNU Modula-2 together with the -gdwarf-2 command line option.
4389 The ARM rdi-share module.
4391 The Netware NLM debug server.
4393 *** Changes in GDB 6.4
4395 * New native configurations
4397 OpenBSD/arm arm*-*-openbsd*
4398 OpenBSD/mips64 mips64-*-openbsd*
4402 Morpho Technologies ms1 ms1-elf
4404 * New command line options
4406 --batch-silent As for --batch, but totally silent.
4407 --return-child-result The debugger will exist with the same value
4408 the child (debugged) program exited with.
4409 --eval-command COMMAND, -ex COMMAND
4410 Execute a single GDB CLI command. This may be
4411 specified multiple times and in conjunction
4412 with the --command (-x) option.
4414 * Deprecated commands removed
4416 The following commands, that were deprecated in 2000, have been
4420 set|show arm disassembly-flavor set|show arm disassembler
4421 othernames set arm disassembler
4422 set|show remotedebug set|show debug remote
4423 set|show archdebug set|show debug arch
4424 set|show eventdebug set|show debug event
4427 * New BSD user-level threads support
4429 It is now possible to debug programs using the user-level threads
4430 library on OpenBSD and FreeBSD. Currently supported (target)
4433 FreeBSD/amd64 x86_64-*-freebsd*
4434 FreeBSD/i386 i386-*-freebsd*
4435 OpenBSD/i386 i386-*-openbsd*
4437 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4438 are not yet supported.
4440 * New support for Matsushita MN10300 w/sim added
4441 (Work in progress). mn10300-elf.
4443 * REMOVED configurations and files
4445 VxWorks and the XDR protocol *-*-vxworks
4446 Motorola MCORE mcore-*-*
4447 National Semiconductor NS32000 ns32k-*-*
4449 * New "set print array-indexes" command
4451 After turning this setting "on", GDB prints the index of each element
4452 when displaying arrays. The default is "off" to preserve the previous
4455 * VAX floating point support
4457 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4459 * User-defined command support
4461 In addition to using $arg0..$arg9 for argument passing, it is now possible
4462 to use $argc to determine now many arguments have been passed. See the
4463 section on user-defined commands in the user manual for more information.
4465 *** Changes in GDB 6.3:
4467 * New command line option
4469 GDB now accepts -l followed by a number to set the timeout for remote
4472 * GDB works with GCC -feliminate-dwarf2-dups
4474 GDB now supports a more compact representation of DWARF-2 debug
4475 information using DW_FORM_ref_addr references. These are produced
4476 by GCC with the option -feliminate-dwarf2-dups and also by some
4477 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4478 to use -feliminate-dwarf2-dups.
4480 * Internationalization
4482 When supported by the host system, GDB will be built with
4483 internationalization (libintl). The task of marking up the sources is
4484 continued, we're looking forward to our first translation.
4488 Initial support for debugging programs compiled with the GNAT
4489 implementation of the Ada programming language has been integrated
4490 into GDB. In this release, support is limited to expression evaluation.
4492 * New native configurations
4494 GNU/Linux/m32r m32r-*-linux-gnu
4498 GDB's remote protocol now includes support for the 'p' packet. This
4499 packet is used to fetch individual registers from a remote inferior.
4501 * END-OF-LIFE registers[] compatibility module
4503 GDB's internal register infrastructure has been completely rewritten.
4504 The new infrastructure making possible the implementation of key new
4505 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4508 GDB 6.3 will be the last release to include the the registers[]
4509 compatibility module that allowed out-of-date configurations to
4510 continue to work. This change directly impacts the following
4520 powerpc bdm protocol
4522 Unless there is activity to revive these configurations, they will be
4523 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4525 * OBSOLETE configurations and files
4527 Configurations that have been declared obsolete in this release have
4528 been commented out. Unless there is activity to revive these
4529 configurations, the next release of GDB will have their sources
4530 permanently REMOVED.
4539 *** Changes in GDB 6.2.1:
4541 * MIPS `break main; run' gave an heuristic-fence-post warning
4543 When attempting to run even a simple program, a warning about
4544 heuristic-fence-post being hit would be reported. This problem has
4547 * MIPS IRIX 'long double' crashed GDB
4549 When examining a long double variable, GDB would get a segmentation
4550 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4551 IRIX long double values).
4555 A bug in the VAX stack code was causing problems with the "next"
4556 command. This problem has been fixed.
4558 *** Changes in GDB 6.2:
4560 * Fix for ``many threads''
4562 On GNU/Linux systems that use the NPTL threads library, a program
4563 rapidly creating and deleting threads would confuse GDB leading to the
4566 ptrace: No such process.
4567 thread_db_get_info: cannot get thread info: generic error
4569 This problem has been fixed.
4571 * "-async" and "-noasync" options removed.
4573 Support for the broken "-noasync" option has been removed (it caused
4576 * New ``start'' command.
4578 This command runs the program until the begining of the main procedure.
4580 * New BSD Kernel Data Access Library (libkvm) interface
4582 Using ``target kvm'' it is now possible to debug kernel core dumps and
4583 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4584 platforms. Currently supported (native-only) configurations are:
4586 FreeBSD/amd64 x86_64-*-freebsd*
4587 FreeBSD/i386 i?86-*-freebsd*
4588 NetBSD/i386 i?86-*-netbsd*
4589 NetBSD/m68k m68*-*-netbsd*
4590 NetBSD/sparc sparc-*-netbsd*
4591 OpenBSD/amd64 x86_64-*-openbsd*
4592 OpenBSD/i386 i?86-*-openbsd*
4593 OpenBSD/m68k m68*-openbsd*
4594 OpenBSD/sparc sparc-*-openbsd*
4596 * Signal trampoline code overhauled
4598 Many generic problems with GDB's signal handling code have been fixed.
4599 These include: backtraces through non-contiguous stacks; recognition
4600 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4601 call; backtrace through a signal trampoline; step into and out of
4602 signal handlers; and single-stepping in the signal trampoline.
4604 Please note that kernel bugs are a limiting factor here. These
4605 features have been shown to work on an s390 GNU/Linux system that
4606 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4608 * Cygwin support for DWARF 2 added.
4610 * New native configurations
4612 GNU/Linux/hppa hppa*-*-linux*
4613 OpenBSD/hppa hppa*-*-openbsd*
4614 OpenBSD/m68k m68*-*-openbsd*
4615 OpenBSD/m88k m88*-*-openbsd*
4616 OpenBSD/powerpc powerpc-*-openbsd*
4617 NetBSD/vax vax-*-netbsd*
4618 OpenBSD/vax vax-*-openbsd*
4620 * END-OF-LIFE frame compatibility module
4622 GDB's internal frame infrastructure has been completely rewritten.
4623 The new infrastructure making it possible to support key new features
4624 including DWARF 2 Call Frame Information. To aid in the task of
4625 migrating old configurations to this new infrastructure, a
4626 compatibility module, that allowed old configurations to continue to
4627 work, was also included.
4629 GDB 6.2 will be the last release to include this frame compatibility
4630 module. This change directly impacts the following configurations:
4640 Unless there is activity to revive these configurations, they will be
4641 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4643 * REMOVED configurations and files
4645 Sun 3, running SunOS 3 m68*-*-sunos3*
4646 Sun 3, running SunOS 4 m68*-*-sunos4*
4647 Sun 2, running SunOS 3 m68000-*-sunos3*
4648 Sun 2, running SunOS 4 m68000-*-sunos4*
4649 Motorola 680x0 running LynxOS m68*-*-lynxos*
4650 AT&T 3b1/Unix pc m68*-att-*
4651 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4652 decstation mips-dec-* mips-little-*
4653 riscos mips-*-riscos* mips-*-sysv*
4654 sonymips mips-sony-*
4655 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4657 *** Changes in GDB 6.1.1:
4659 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4661 The TUI (Text-mode User Interface) is now built as part of a default
4662 GDB configuration. It is enabled by either selecting the TUI with the
4663 command line option "-i=tui" or by running the separate "gdbtui"
4664 program. For more information on the TUI, see the manual "Debugging
4667 * Pending breakpoint support (also included in GDB 6.1)
4669 Support has been added to allow you to specify breakpoints in shared
4670 libraries that have not yet been loaded. If a breakpoint location
4671 cannot be found, and the "breakpoint pending" option is set to auto,
4672 GDB queries you if you wish to make the breakpoint pending on a future
4673 shared-library load. If and when GDB resolves the breakpoint symbol,
4674 the pending breakpoint is removed as one or more regular breakpoints
4677 Pending breakpoints are very useful for GCJ Java debugging.
4679 * Fixed ISO-C build problems
4681 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4682 non ISO-C code that stopped them being built using a more strict ISO-C
4683 compiler (e.g., IBM's C compiler).
4685 * Fixed build problem on IRIX 5
4687 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4688 wasn't able to compile compile on an IRIX 5 system.
4690 * Added execute permission to gdb/gdbserver/configure
4692 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4693 permission. This bug would cause configure to fail on a number of
4694 systems (Solaris, IRIX). Ref: server/519.
4696 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4698 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4699 has been updated to use constant array sizes.
4701 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4703 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4704 its generated DWARF Call Frame Info. This encoding was causing GDB to
4705 panic, that panic has been fixed. Ref: gdb/1628.
4707 * Fixed a problem when examining parameters in shared library code.
4709 When examining parameters in optimized shared library code generated
4710 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4711 not available''. GDB now correctly displays the variable's value.
4713 *** Changes in GDB 6.1:
4715 * Removed --with-mmalloc
4717 Support for the mmalloc memory manager has been removed, as it
4718 conflicted with the internal gdb byte cache.
4720 * Changes in AMD64 configurations
4722 The AMD64 target now includes the %cs and %ss registers. As a result
4723 the AMD64 remote protocol has changed; this affects the floating-point
4724 and SSE registers. If you rely on those registers for your debugging,
4725 you should upgrade gdbserver on the remote side.
4727 * Revised SPARC target
4729 The SPARC target has been completely revised, incorporating the
4730 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4731 support for LynxOS and SunOS 4 has been dropped. Calling functions
4732 from within GDB on operating systems with a non-executable stack
4733 (Solaris, OpenBSD) now works.
4737 GDB has a new C++ demangler which does a better job on the mangled
4738 names generated by current versions of g++. It also runs faster, so
4739 with this and other changes gdb should now start faster on large C++
4742 * DWARF 2 Location Expressions
4744 GDB support for location expressions has been extended to support function
4745 arguments and frame bases. Older versions of GDB could crash when they
4748 * C++ nested types and namespaces
4750 GDB's support for nested types and namespaces in C++ has been
4751 improved, especially if you use the DWARF 2 debugging format. (This
4752 is the default for recent versions of GCC on most platforms.)
4753 Specifically, if you have a class "Inner" defined within a class or
4754 namespace "Outer", then GDB realizes that the class's name is
4755 "Outer::Inner", not simply "Inner". This should greatly reduce the
4756 frequency of complaints about not finding RTTI symbols. In addition,
4757 if you are stopped at inside of a function defined within a namespace,
4758 GDB modifies its name lookup accordingly.
4760 * New native configurations
4762 NetBSD/amd64 x86_64-*-netbsd*
4763 OpenBSD/amd64 x86_64-*-openbsd*
4764 OpenBSD/alpha alpha*-*-openbsd*
4765 OpenBSD/sparc sparc-*-openbsd*
4766 OpenBSD/sparc64 sparc64-*-openbsd*
4768 * New debugging protocols
4770 M32R with SDI protocol m32r-*-elf*
4772 * "set prompt-escape-char" command deleted.
4774 The command "set prompt-escape-char" has been deleted. This command,
4775 and its very obscure effet on GDB's prompt, was never documented,
4776 tested, nor mentioned in the NEWS file.
4778 * OBSOLETE configurations and files
4780 Configurations that have been declared obsolete in this release have
4781 been commented out. Unless there is activity to revive these
4782 configurations, the next release of GDB will have their sources
4783 permanently REMOVED.
4785 Sun 3, running SunOS 3 m68*-*-sunos3*
4786 Sun 3, running SunOS 4 m68*-*-sunos4*
4787 Sun 2, running SunOS 3 m68000-*-sunos3*
4788 Sun 2, running SunOS 4 m68000-*-sunos4*
4789 Motorola 680x0 running LynxOS m68*-*-lynxos*
4790 AT&T 3b1/Unix pc m68*-att-*
4791 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4792 decstation mips-dec-* mips-little-*
4793 riscos mips-*-riscos* mips-*-sysv*
4794 sonymips mips-sony-*
4795 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4797 * REMOVED configurations and files
4799 SGI Irix-4.x mips-sgi-irix4 or iris4
4800 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4801 Z8000 simulator z8k-zilog-none or z8ksim
4802 Matsushita MN10200 w/simulator mn10200-*-*
4803 H8/500 simulator h8500-hitachi-hms or h8500hms
4804 HP/PA running BSD hppa*-*-bsd*
4805 HP/PA running OSF/1 hppa*-*-osf*
4806 HP/PA Pro target hppa*-*-pro*
4807 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4808 386BSD i[3456]86-*-bsd*
4809 Sequent family i[3456]86-sequent-sysv4*
4810 i[3456]86-sequent-sysv*
4811 i[3456]86-sequent-bsd*
4812 SPARC running LynxOS sparc-*-lynxos*
4813 SPARC running SunOS 4 sparc-*-sunos4*
4814 Tsqware Sparclet sparclet-*-*
4815 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4817 *** Changes in GDB 6.0:
4821 Support for debugging the Objective-C programming language has been
4822 integrated into GDB.
4824 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4826 DWARF 2's Call Frame Information makes available compiler generated
4827 information that more exactly describes the program's run-time stack.
4828 By using this information, GDB is able to provide more robust stack
4831 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4832 have been updated to use a new backtrace mechanism which includes
4833 DWARF 2 CFI support.
4837 GDB's remote protocol has been extended to include support for hosted
4838 file I/O (where the remote target uses GDB's file system). See GDB's
4839 remote protocol documentation for details.
4841 * All targets using the new architecture framework.
4843 All of GDB's targets have been updated to use the new internal
4844 architecture framework. The way is now open for future GDB releases
4845 to include cross-architecture native debugging support (i386 on amd64,
4848 * GNU/Linux's Thread Local Storage (TLS)
4850 GDB now includes support for for the GNU/Linux implementation of
4851 per-thread variables.
4853 * GNU/Linux's Native POSIX Thread Library (NPTL)
4855 GDB's thread code has been updated to work with either the new
4856 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4858 * Separate debug info.
4860 GDB, in conjunction with BINUTILS, now supports a mechanism for
4861 automatically loading debug information from a separate file. Instead
4862 of shipping full debug and non-debug versions of system libraries,
4863 system integrators can now instead ship just the stripped libraries
4864 and optional debug files.
4866 * DWARF 2 Location Expressions
4868 DWARF 2 Location Expressions allow the compiler to more completely
4869 describe the location of variables (even in optimized code) to the
4872 GDB now includes preliminary support for location expressions (support
4873 for DW_OP_piece is still missing).
4877 A number of long standing bugs that caused GDB to die while starting a
4878 Java application have been fixed. GDB's Java support is now
4879 considered "useable".
4881 * GNU/Linux support for fork, vfork, and exec.
4883 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4884 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4887 * GDB supports logging output to a file
4889 There are two new commands, "set logging" and "show logging", which can be
4890 used to capture GDB's output to a file.
4892 * The meaning of "detach" has changed for gdbserver
4894 The "detach" command will now resume the application, as documented. To
4895 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4898 * d10v, m68hc11 `regs' command deprecated
4900 The `info registers' command has been updated so that it displays the
4901 registers using a format identical to the old `regs' command.
4905 A new command, "maint set profile on/off", has been added. This command can
4906 be used to enable or disable profiling while running GDB, to profile a
4907 session or a set of commands. In addition there is a new configure switch,
4908 "--enable-profiling", which will cause GDB to be compiled with profiling
4909 data, for more informative profiling results.
4911 * Default MI syntax changed to "mi2".
4913 The default MI (machine interface) syntax, enabled by the command line
4914 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4915 "mi1", can be enabled by specifying the option "-i=mi1".
4917 Support for the original "mi0" syntax (included in GDB 5.0) has been
4920 Fix for gdb/192: removed extraneous space when displaying frame level.
4921 Fix for gdb/672: update changelist is now output in mi list format.
4922 Fix for gdb/702: a -var-assign that updates the value now shows up
4923 in a subsequent -var-update.
4925 * New native configurations.
4927 FreeBSD/amd64 x86_64-*-freebsd*
4929 * Multi-arched targets.
4931 HP/PA HPUX11 hppa*-*-hpux*
4932 Renesas M32R/D w/simulator m32r-*-elf*
4934 * OBSOLETE configurations and files
4936 Configurations that have been declared obsolete in this release have
4937 been commented out. Unless there is activity to revive these
4938 configurations, the next release of GDB will have their sources
4939 permanently REMOVED.
4941 Z8000 simulator z8k-zilog-none or z8ksim
4942 Matsushita MN10200 w/simulator mn10200-*-*
4943 H8/500 simulator h8500-hitachi-hms or h8500hms
4944 HP/PA running BSD hppa*-*-bsd*
4945 HP/PA running OSF/1 hppa*-*-osf*
4946 HP/PA Pro target hppa*-*-pro*
4947 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4948 Sequent family i[3456]86-sequent-sysv4*
4949 i[3456]86-sequent-sysv*
4950 i[3456]86-sequent-bsd*
4951 Tsqware Sparclet sparclet-*-*
4952 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4954 * REMOVED configurations and files
4957 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4958 IBM AIX PS/2 i[3456]86-*-aix
4959 i386 running Mach 3.0 i[3456]86-*-mach3*
4960 i386 running Mach i[3456]86-*-mach*
4961 i386 running OSF/1 i[3456]86-*osf1mk*
4962 HP/Apollo 68k Family m68*-apollo*-sysv*,
4964 m68*-hp-bsd*, m68*-hp-hpux*
4965 Argonaut Risc Chip (ARC) arc-*-*
4966 Mitsubishi D30V d30v-*-*
4967 Fujitsu FR30 fr30-*-elf*
4968 OS/9000 i[34]86-*-os9k
4969 I960 with MON960 i960-*-coff
4971 * MIPS $fp behavior changed
4973 The convenience variable $fp, for the MIPS, now consistently returns
4974 the address of the current frame's base. Previously, depending on the
4975 context, $fp could refer to either $sp or the current frame's base
4976 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4977 The GNU Source-Level Debugger''.
4979 *** Changes in GDB 5.3:
4981 * GNU/Linux shared library multi-threaded performance improved.
4983 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4984 `/proc', in preference to `ptrace' for memory reads. This may result
4985 in an improvement in the start-up time of multi-threaded, shared
4986 library applications when run under GDB. One GDB user writes: ``loads
4987 shared libs like mad''.
4989 * ``gdbserver'' now supports multi-threaded applications on some targets
4991 Support for debugging multi-threaded applications which use
4992 the GNU/Linux LinuxThreads package has been added for
4993 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4994 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4996 * GDB now supports C/C++ preprocessor macros.
4998 GDB now expands preprocessor macro invocations in C/C++ expressions,
4999 and provides various commands for showing macro definitions and how
5002 The new command `macro expand EXPRESSION' expands any macro
5003 invocations in expression, and shows the result.
5005 The new command `show macro MACRO-NAME' shows the definition of the
5006 macro named MACRO-NAME, and where it was defined.
5008 Most compilers don't include information about macros in the debugging
5009 information by default. In GCC 3.1, for example, you need to compile
5010 your program with the options `-gdwarf-2 -g3'. If the macro
5011 information is present in the executable, GDB will read it.
5013 * Multi-arched targets.
5015 DEC Alpha (partial) alpha*-*-*
5016 DEC VAX (partial) vax-*-*
5018 National Semiconductor NS32000 (partial) ns32k-*-*
5019 Motorola 68000 (partial) m68k-*-*
5020 Motorola MCORE mcore-*-*
5024 Fujitsu FRV architecture added by Red Hat frv*-*-*
5027 * New native configurations
5029 Alpha NetBSD alpha*-*-netbsd*
5030 SH NetBSD sh*-*-netbsdelf*
5031 MIPS NetBSD mips*-*-netbsd*
5032 UltraSPARC NetBSD sparc64-*-netbsd*
5034 * OBSOLETE configurations and files
5036 Configurations that have been declared obsolete in this release have
5037 been commented out. Unless there is activity to revive these
5038 configurations, the next release of GDB will have their sources
5039 permanently REMOVED.
5041 Mitsubishi D30V d30v-*-*
5042 OS/9000 i[34]86-*-os9k
5043 IBM AIX PS/2 i[3456]86-*-aix
5044 Fujitsu FR30 fr30-*-elf*
5045 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5046 Argonaut Risc Chip (ARC) arc-*-*
5047 i386 running Mach 3.0 i[3456]86-*-mach3*
5048 i386 running Mach i[3456]86-*-mach*
5049 i386 running OSF/1 i[3456]86-*osf1mk*
5050 HP/Apollo 68k Family m68*-apollo*-sysv*,
5052 m68*-hp-bsd*, m68*-hp-hpux*
5053 I960 with MON960 i960-*-coff
5055 * OBSOLETE languages
5057 CHILL, a Pascal like language used by telecommunications companies.
5059 * REMOVED configurations and files
5061 AMD 29k family via UDI a29k-amd-udi, udi29k
5062 A29K VxWorks a29k-*-vxworks
5063 AMD 29000 embedded, using EBMON a29k-none-none
5064 AMD 29000 embedded with COFF a29k-none-coff
5065 AMD 29000 embedded with a.out a29k-none-aout
5067 testsuite/gdb.hp/gdb.threads-hp/ directory
5069 * New command "set max-user-call-depth <nnn>"
5071 This command allows the user to limit the call depth of user-defined
5072 commands. The default is 1024.
5074 * Changes in FreeBSD/i386 native debugging.
5076 Support for the "generate-core-file" has been added.
5078 * New commands "dump", "append", and "restore".
5080 These commands allow data to be copied from target memory
5081 to a bfd-format or binary file (dump and append), and back
5082 from a file into memory (restore).
5084 * Improved "next/step" support on multi-processor Alpha Tru64.
5086 The previous single-step mechanism could cause unpredictable problems,
5087 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5088 of a software single-step mechanism prevents this.
5090 *** Changes in GDB 5.2.1:
5098 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5099 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5100 Fix, by Joel Brobecker imported from mainline.
5102 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5103 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5104 Fix, by Fred Fish, imported from mainline.
5106 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5107 Surprisingly enough, it works now.
5108 By Michal Ludvig, imported from mainline.
5110 i386 hardware watchpoint support:
5111 avoid misses on second run for some targets.
5112 By Pierre Muller, imported from mainline.
5114 *** Changes in GDB 5.2:
5116 * New command "set trust-readonly-sections on[off]".
5118 This command is a hint that tells gdb that read-only sections
5119 really are read-only (ie. that their contents will not change).
5120 In this mode, gdb will go to the object file rather than the
5121 target to read memory from read-only sections (such as ".text").
5122 This can be a significant performance improvement on some
5123 (notably embedded) targets.
5125 * New command "generate-core-file" (or "gcore").
5127 This new gdb command allows the user to drop a core file of the child
5128 process state at any time. So far it's been implemented only for
5129 GNU/Linux and Solaris, but should be relatively easily ported to other
5130 hosts. Argument is core file name (defaults to core.<pid>).
5132 * New command line option
5134 GDB now accepts --pid or -p followed by a process id.
5136 * Change in command line behavior -- corefiles vs. process ids.
5138 There is a subtle behavior in the way in which GDB handles
5139 command line arguments. The first non-flag argument is always
5140 a program to debug, but the second non-flag argument may either
5141 be a corefile or a process id. Previously, GDB would attempt to
5142 open the second argument as a corefile, and if that failed, would
5143 issue a superfluous error message and then attempt to attach it as
5144 a process. Now, if the second argument begins with a non-digit,
5145 it will be treated as a corefile. If it begins with a digit,
5146 GDB will attempt to attach it as a process, and if no such process
5147 is found, will then attempt to open it as a corefile.
5149 * Changes in ARM configurations.
5151 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5152 configuration is fully multi-arch.
5154 * New native configurations
5156 ARM NetBSD arm*-*-netbsd*
5157 x86 OpenBSD i[3456]86-*-openbsd*
5158 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5159 Sparc64 running FreeBSD sparc64-*-freebsd*
5163 Sanyo XStormy16 xstormy16-elf
5165 * OBSOLETE configurations and files
5167 Configurations that have been declared obsolete in this release have
5168 been commented out. Unless there is activity to revive these
5169 configurations, the next release of GDB will have their sources
5170 permanently REMOVED.
5172 AMD 29k family via UDI a29k-amd-udi, udi29k
5173 A29K VxWorks a29k-*-vxworks
5174 AMD 29000 embedded, using EBMON a29k-none-none
5175 AMD 29000 embedded with COFF a29k-none-coff
5176 AMD 29000 embedded with a.out a29k-none-aout
5178 testsuite/gdb.hp/gdb.threads-hp/ directory
5180 * REMOVED configurations and files
5182 TI TMS320C80 tic80-*-*
5184 PowerPC Solaris powerpcle-*-solaris*
5185 PowerPC Windows NT powerpcle-*-cygwin32
5186 PowerPC Netware powerpc-*-netware*
5187 Harris/CXUX m88k m88*-harris-cxux*
5188 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5189 ns32k-utek-sysv* ns32k-utek-*
5190 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5191 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5192 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5193 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5194 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5196 * Changes to command line processing
5198 The new `--args' feature can be used to specify command-line arguments
5199 for the inferior from gdb's command line.
5201 * Changes to key bindings
5203 There is a new `operate-and-get-next' function bound to `C-o'.
5205 *** Changes in GDB 5.1.1
5207 Fix compile problem on DJGPP.
5209 Fix a problem with floating-point registers on the i386 being
5212 Fix to stop GDB crashing on .debug_str debug info.
5214 Numerous documentation fixes.
5216 Numerous testsuite fixes.
5218 *** Changes in GDB 5.1:
5220 * New native configurations
5222 Alpha FreeBSD alpha*-*-freebsd*
5223 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5224 MIPS GNU/Linux mips*-*-linux*
5225 MIPS SGI Irix 6.x mips*-sgi-irix6*
5226 ia64 AIX ia64-*-aix*
5227 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5231 Motorola 68HC11 and 68HC12 m68hc11-elf
5233 UltraSparc running GNU/Linux sparc64-*-linux*
5235 * OBSOLETE configurations and files
5237 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5238 Harris/CXUX m88k m88*-harris-cxux*
5239 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5240 ns32k-utek-sysv* ns32k-utek-*
5241 TI TMS320C80 tic80-*-*
5243 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5244 PowerPC Solaris powerpcle-*-solaris*
5245 PowerPC Windows NT powerpcle-*-cygwin32
5246 PowerPC Netware powerpc-*-netware*
5247 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5248 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5249 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5250 Apple Macintosh (MPW) host N/A
5252 stuff.c (Program to stuff files into a specially prepared space in kdb)
5253 kdb-start.c (Main loop for the standalone kernel debugger)
5255 Configurations that have been declared obsolete in this release have
5256 been commented out. Unless there is activity to revive these
5257 configurations, the next release of GDB will have their sources
5258 permanently REMOVED.
5260 * REMOVED configurations and files
5262 Altos 3068 m68*-altos-*
5263 Convex c1-*-*, c2-*-*
5265 ARM RISCix arm-*-* (as host)
5269 * GDB has been converted to ISO C.
5271 GDB's source code has been converted to ISO C. In particular, the
5272 sources are fully protoized, and rely on standard headers being
5277 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5279 * The MI enabled by default.
5281 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5282 revised and enabled by default. Packages which use GDB as a debugging
5283 engine behind a UI or another front end are encouraged to switch to
5284 using the GDB/MI interface, instead of the old annotations interface
5285 which is now deprecated.
5287 * Support for debugging Pascal programs.
5289 GDB now includes support for debugging Pascal programs. The following
5290 main features are supported:
5292 - Pascal-specific data types such as sets;
5294 - automatic recognition of Pascal sources based on file-name
5297 - Pascal-style display of data types, variables, and functions;
5299 - a Pascal expression parser.
5301 However, some important features are not yet supported.
5303 - Pascal string operations are not supported at all;
5305 - there are some problems with boolean types;
5307 - Pascal type hexadecimal constants are not supported
5308 because they conflict with the internal variables format;
5310 - support for Pascal objects and classes is not full yet;
5312 - unlike Pascal, GDB is case-sensitive for symbol names.
5314 * Changes in completion.
5316 Commands such as `shell', `run' and `set args', which pass arguments
5317 to inferior programs, now complete on file names, similar to what
5318 users expect at the shell prompt.
5320 Commands which accept locations, such as `disassemble', `print',
5321 `breakpoint', `until', etc. now complete on filenames as well as
5322 program symbols. Thus, if you type "break foob TAB", and the source
5323 files linked into the programs include `foobar.c', that file name will
5324 be one of the candidates for completion. However, file names are not
5325 considered for completion after you typed a colon that delimits a file
5326 name from a name of a function in that file, as in "break foo.c:bar".
5328 `set demangle-style' completes on available demangling styles.
5330 * New platform-independent commands:
5332 It is now possible to define a post-hook for a command as well as a
5333 hook that runs before the command. For more details, see the
5334 documentation of `hookpost' in the GDB manual.
5336 * Changes in GNU/Linux native debugging.
5338 Support for debugging multi-threaded programs has been completely
5339 revised for all platforms except m68k and sparc. You can now debug as
5340 many threads as your system allows you to have.
5342 Attach/detach is supported for multi-threaded programs.
5344 Support for SSE registers was added for x86. This doesn't work for
5345 multi-threaded programs though.
5347 * Changes in MIPS configurations.
5349 Multi-arch support is enabled for all MIPS configurations.
5351 GDB can now be built as native debugger on SGI Irix 6.x systems for
5352 debugging n32 executables. (Debugging 64-bit executables is not yet
5355 * Unified support for hardware watchpoints in all x86 configurations.
5357 Most (if not all) native x86 configurations support hardware-assisted
5358 breakpoints and watchpoints in a unified manner. This support
5359 implements debug register sharing between watchpoints, which allows to
5360 put a virtually infinite number of watchpoints on the same address,
5361 and also supports watching regions up to 16 bytes with several debug
5364 The new maintenance command `maintenance show-debug-regs' toggles
5365 debugging print-outs in functions that insert, remove, and test
5366 watchpoints and hardware breakpoints.
5368 * Changes in the DJGPP native configuration.
5370 New command ``info dos sysinfo'' displays assorted information about
5371 the CPU, OS, memory, and DPMI server.
5373 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5374 display information about segment descriptors stored in GDT, LDT, and
5377 New commands ``info dos pde'' and ``info dos pte'' display entries
5378 from Page Directory and Page Tables (for now works with CWSDPMI only).
5379 New command ``info dos address-pte'' displays the Page Table entry for
5380 a given linear address.
5382 GDB can now pass command lines longer than 126 characters to the
5383 program being debugged (requires an update to the libdbg.a library
5384 which is part of the DJGPP development kit).
5386 DWARF2 debug info is now supported.
5388 It is now possible to `step' and `next' through calls to `longjmp'.
5390 * Changes in documentation.
5392 All GDB documentation was converted to GFDL, the GNU Free
5393 Documentation License.
5395 Tracepoints-related commands are now fully documented in the GDB
5398 TUI, the Text-mode User Interface, is now documented in the manual.
5400 Tracepoints-related commands are now fully documented in the GDB
5403 The "GDB Internals" manual now has an index. It also includes
5404 documentation of `ui_out' functions, GDB coding standards, x86
5405 hardware watchpoints, and memory region attributes.
5407 * GDB's version number moved to ``version.in''
5409 The Makefile variable VERSION has been replaced by the file
5410 ``version.in''. People creating GDB distributions should update the
5411 contents of this file.
5415 GUD support is now a standard part of the EMACS distribution.
5417 *** Changes in GDB 5.0:
5419 * Improved support for debugging FP programs on x86 targets
5421 Unified and much-improved support for debugging floating-point
5422 programs on all x86 targets. In particular, ``info float'' now
5423 displays the FP registers in the same format on all x86 targets, with
5424 greater level of detail.
5426 * Improvements and bugfixes in hardware-assisted watchpoints
5428 It is now possible to watch array elements, struct members, and
5429 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5430 on x86 targets no longer erroneously trigger when the address is
5433 * Improvements in the native DJGPP version of GDB
5435 The distribution now includes all the scripts and auxiliary files
5436 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5437 machines ``out of the box''.
5439 The DJGPP version can now debug programs that use signals. It is
5440 possible to catch signals that happened in the debuggee, deliver
5441 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5442 would kill the program being debugged.) Programs that hook hardware
5443 interrupts (keyboard, timer, etc.) can also be debugged.
5445 It is now possible to debug DJGPP programs that redirect their
5446 standard handles or switch them to raw (as opposed to cooked) mode, or
5447 even close them. The command ``run < foo > bar'' works as expected,
5448 and ``info terminal'' reports useful information about the debuggee's
5449 terminal, including raw/cooked mode, redirection, etc.
5451 The DJGPP version now uses termios functions for console I/O, which
5452 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5455 DOS-style file names with drive letters are now fully supported by
5458 It is now possible to debug DJGPP programs that switch their working
5459 directory. It is also possible to rerun the debuggee any number of
5460 times without restarting GDB; thus, you can use the same setup,
5461 breakpoints, etc. for many debugging sessions.
5463 * New native configurations
5465 ARM GNU/Linux arm*-*-linux*
5466 PowerPC GNU/Linux powerpc-*-linux*
5470 Motorola MCore mcore-*-*
5471 x86 VxWorks i[3456]86-*-vxworks*
5472 PowerPC VxWorks powerpc-*-vxworks*
5473 TI TMS320C80 tic80-*-*
5475 * OBSOLETE configurations
5477 Altos 3068 m68*-altos-*
5478 Convex c1-*-*, c2-*-*
5480 ARM RISCix arm-*-* (as host)
5483 Configurations that have been declared obsolete will be commented out,
5484 but the code will be left in place. If there is no activity to revive
5485 these configurations before the next release of GDB, the sources will
5486 be permanently REMOVED.
5488 * Gould support removed
5490 Support for the Gould PowerNode and NP1 has been removed.
5492 * New features for SVR4
5494 On SVR4 native platforms (such as Solaris), if you attach to a process
5495 without first loading a symbol file, GDB will now attempt to locate and
5496 load symbols from the running process's executable file.
5498 * Many C++ enhancements
5500 C++ support has been greatly improved. Overload resolution now works properly
5501 in almost all cases. RTTI support is on the way.
5503 * Remote targets can connect to a sub-program
5505 A popen(3) style serial-device has been added. This device starts a
5506 sub-process (such as a stand-alone simulator) and then communicates
5507 with that. The sub-program to run is specified using the syntax
5508 ``|<program> <args>'' vis:
5510 (gdb) set remotedebug 1
5511 (gdb) target extended-remote |mn10300-elf-sim program-args
5513 * MIPS 64 remote protocol
5515 A long standing bug in the mips64 remote protocol where by GDB
5516 expected certain 32 bit registers (ex SR) to be transfered as 32
5517 instead of 64 bits has been fixed.
5519 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5520 added to provide backward compatibility with older versions of GDB.
5522 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5524 The command ``set remotebinarydownload'' command has been replaced by
5525 ``set remote X-packet''. Other commands in ``set remote'' family
5526 include ``set remote P-packet''.
5528 * Breakpoint commands accept ranges.
5530 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5531 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5532 ``tracepoint passcount'' also accepts a range of tracepoints.
5534 * ``apropos'' command added.
5536 The ``apropos'' command searches through command names and
5537 documentation strings, printing out matches, making it much easier to
5538 try to find a command that does what you are looking for.
5542 A new machine oriented interface (MI) has been added to GDB. This
5543 interface is designed for debug environments running GDB as a separate
5544 process. This is part of the long term libGDB project. See the
5545 "GDB/MI" chapter of the GDB manual for further information. It can be
5546 enabled by configuring with:
5548 .../configure --enable-gdbmi
5550 *** Changes in GDB-4.18:
5552 * New native configurations
5554 HP-UX 10.20 hppa*-*-hpux10.20
5555 HP-UX 11.x hppa*-*-hpux11.0*
5556 M68K GNU/Linux m68*-*-linux*
5560 Fujitsu FR30 fr30-*-elf*
5561 Intel StrongARM strongarm-*-*
5562 Mitsubishi D30V d30v-*-*
5564 * OBSOLETE configurations
5566 Gould PowerNode, NP1 np1-*-*, pn-*-*
5568 Configurations that have been declared obsolete will be commented out,
5569 but the code will be left in place. If there is no activity to revive
5570 these configurations before the next release of GDB, the sources will
5571 be permanently REMOVED.
5575 As a compatibility experiment, GDB's source files buildsym.h and
5576 buildsym.c have been converted to pure standard C, no longer
5577 containing any K&R compatibility code. We believe that all systems in
5578 use today either come with a standard C compiler, or have a GCC port
5579 available. If this is not true, please report the affected
5580 configuration to bug-gdb@gnu.org immediately. See the README file for
5581 information about getting a standard C compiler if you don't have one
5586 GDB now uses readline 2.2.
5588 * set extension-language
5590 You can now control the mapping between filename extensions and source
5591 languages by using the `set extension-language' command. For instance,
5592 you can ask GDB to treat .c files as C++ by saying
5593 set extension-language .c c++
5594 The command `info extensions' lists all of the recognized extensions
5595 and their associated languages.
5597 * Setting processor type for PowerPC and RS/6000
5599 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5600 you can use the `set processor' command to specify what variant of the
5601 PowerPC family you are debugging. The command
5605 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5606 following PowerPC and RS6000 variants:
5608 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5609 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5611 403GC IBM PowerPC 403GC
5612 505 Motorola PowerPC 505
5613 860 Motorola PowerPC 860 or 850
5614 601 Motorola PowerPC 601
5615 602 Motorola PowerPC 602
5616 603 Motorola/IBM PowerPC 603 or 603e
5617 604 Motorola PowerPC 604 or 604e
5618 750 Motorola/IBM PowerPC 750 or 750
5620 At the moment, this command just tells GDB what to name the
5621 special-purpose processor registers. Since almost all the affected
5622 registers are inaccessible to user-level programs, this command is
5623 only useful for remote debugging in its present form.
5627 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5628 more extensive support for HP-UX. Added features include shared
5629 library support, kernel threads and hardware watchpoints for 11.00,
5630 support for HP's ANSI C and C++ compilers, and a compatibility mode
5631 for xdb and dbx commands.
5635 HP's donation includes the new concept of catchpoints, which is a
5636 generalization of the old catch command. On HP-UX, it is now possible
5637 to catch exec, fork, and vfork, as well as library loading.
5639 This means that the existing catch command has changed; its first
5640 argument now specifies the type of catch to be set up. See the
5641 output of "help catch" for a list of catchpoint types.
5643 * Debugging across forks
5645 On HP-UX, you can choose which process to debug when a fork() happens
5650 HP has donated a curses-based terminal user interface (TUI). To get
5651 it, build with --enable-tui. Although this can be enabled for any
5652 configuration, at present it only works for native HP debugging.
5654 * GDB remote protocol additions
5656 A new protocol packet 'X' that writes binary data is now available.
5657 Default behavior is to try 'X', then drop back to 'M' if the stub
5658 fails to respond. The settable variable `remotebinarydownload'
5659 allows explicit control over the use of 'X'.
5661 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5662 full 64-bit address. The command
5664 set remoteaddresssize 32
5666 can be used to revert to the old behaviour. For existing remote stubs
5667 the change should not be noticed, as the additional address information
5670 In order to assist in debugging stubs, you may use the maintenance
5671 command `packet' to send any text string to the stub. For instance,
5673 maint packet heythere
5675 sends the packet "$heythere#<checksum>". Note that it is very easy to
5676 disrupt a debugging session by sending the wrong packet at the wrong
5679 The compare-sections command allows you to compare section data on the
5680 target to what is in the executable file without uploading or
5681 downloading, by comparing CRC checksums.
5683 * Tracing can collect general expressions
5685 You may now collect general expressions at tracepoints. This requires
5686 further additions to the target-side stub; see tracepoint.c and
5687 doc/agentexpr.texi for further details.
5689 * mask-address variable for Mips
5691 For Mips targets, you may control the zeroing of the upper 32 bits of
5692 a 64-bit address by entering `set mask-address on'. This is mainly
5693 of interest to users of embedded R4xxx and R5xxx processors.
5695 * Higher serial baud rates
5697 GDB's serial code now allows you to specify baud rates 57600, 115200,
5698 230400, and 460800 baud. (Note that your host system may not be able
5699 to achieve all of these rates.)
5703 The i960 configuration now includes an initial implementation of a
5704 builtin simulator, contributed by Jim Wilson.
5707 *** Changes in GDB-4.17:
5709 * New native configurations
5711 Alpha GNU/Linux alpha*-*-linux*
5712 Unixware 2.x i[3456]86-unixware2*
5713 Irix 6.x mips*-sgi-irix6*
5714 PowerPC GNU/Linux powerpc-*-linux*
5715 PowerPC Solaris powerpcle-*-solaris*
5716 Sparc GNU/Linux sparc-*-linux*
5717 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5721 Argonaut Risc Chip (ARC) arc-*-*
5722 Hitachi H8/300S h8300*-*-*
5723 Matsushita MN10200 w/simulator mn10200-*-*
5724 Matsushita MN10300 w/simulator mn10300-*-*
5725 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5726 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5727 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5728 Mitsubishi D10V w/simulator d10v-*-*
5729 Mitsubishi M32R/D w/simulator m32r-*-elf*
5730 Tsqware Sparclet sparclet-*-*
5731 NEC V850 w/simulator v850-*-*
5733 * New debugging protocols
5735 ARM with RDI protocol arm*-*-*
5736 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5737 DDB and LSI variants of PMON protocol mips*-*-*
5738 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5739 PowerPC with SDS protocol powerpc{,le}-*-eabi
5740 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5744 All configurations can now understand and use the DWARF 2 debugging
5745 format. The choice is automatic, if the symbol file contains DWARF 2
5750 GDB now includes basic Java language support. This support is
5751 only useful with Java compilers that produce native machine code.
5753 * solib-absolute-prefix and solib-search-path
5755 For SunOS and SVR4 shared libraries, you may now set the prefix for
5756 loading absolute shared library symbol files, and the search path for
5757 locating non-absolute shared library symbol files.
5759 * Live range splitting
5761 GDB can now effectively debug code for which GCC has performed live
5762 range splitting as part of its optimization. See gdb/doc/LRS for
5763 more details on the expected format of the stabs information.
5767 GDB's support for the GNU Hurd, including thread debugging, has been
5768 updated to work with current versions of the Hurd.
5772 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5773 instruction set. ARM GDB automatically detects when Thumb
5774 instructions are in use, and adjusts disassembly and backtracing
5779 GDB's MIPS target configurations now handle the MIP16 16-bit
5784 GDB now includes support for overlays; if an executable has been
5785 linked such that multiple sections are based at the same address, GDB
5786 will decide which section to use for symbolic info. You can choose to
5787 control the decision manually, using overlay commands, or implement
5788 additional target-side support and use "overlay load-target" to bring
5789 in the overlay mapping. Do "help overlay" for more detail.
5793 The command "info symbol <address>" displays information about
5794 the symbol at the specified address.
5798 The standard remote protocol now includes an extension that allows
5799 asynchronous collection and display of trace data. This requires
5800 extensive support in the target-side debugging stub. Tracing mode
5801 includes a new interaction mode in GDB and new commands: see the
5802 file tracepoint.c for more details.
5806 Configurations for embedded MIPS now include a simulator contributed
5807 by Cygnus Solutions. The simulator supports the instruction sets
5808 of most MIPS variants.
5812 Sparc configurations may now include the ERC32 simulator contributed
5813 by the European Space Agency. The simulator is not built into
5814 Sparc targets by default; configure with --enable-sim to include it.
5818 For target configurations that may include multiple variants of a
5819 basic architecture (such as MIPS and SH), you may now set the
5820 architecture explicitly. "set arch" sets, "info arch" lists
5821 the possible architectures.
5823 *** Changes in GDB-4.16:
5825 * New native configurations
5827 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5828 M68K NetBSD m68k-*-netbsd*
5829 PowerPC AIX 4.x powerpc-*-aix*
5830 PowerPC MacOS powerpc-*-macos*
5831 PowerPC Windows NT powerpcle-*-cygwin32
5832 RS/6000 AIX 4.x rs6000-*-aix4*
5836 ARM with RDP protocol arm-*-*
5837 I960 with MON960 i960-*-coff
5838 MIPS VxWorks mips*-*-vxworks*
5839 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5840 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5842 Matra Sparclet sparclet-*-*
5846 The powerpc-eabi configuration now includes the PSIM simulator,
5847 contributed by Andrew Cagney, with assistance from Mike Meissner.
5848 PSIM is a very elaborate model of the PowerPC, including not only
5849 basic instruction set execution, but also details of execution unit
5850 performance and I/O hardware. See sim/ppc/README for more details.
5854 GDB now works with Solaris 2.5.
5856 * Windows 95/NT native
5858 GDB will now work as a native debugger on Windows 95 and Windows NT.
5859 To build it from source, you must use the "gnu-win32" environment,
5860 which uses a DLL to emulate enough of Unix to run the GNU tools.
5861 Further information, binaries, and sources are available at
5862 ftp.cygnus.com, under pub/gnu-win32.
5864 * dont-repeat command
5866 If a user-defined command includes the command `dont-repeat', then the
5867 command will not be repeated if the user just types return. This is
5868 useful if the command is time-consuming to run, so that accidental
5869 extra keystrokes don't run the same command many times.
5871 * Send break instead of ^C
5873 The standard remote protocol now includes an option to send a break
5874 rather than a ^C to the target in order to interrupt it. By default,
5875 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5877 * Remote protocol timeout
5879 The standard remote protocol includes a new variable `remotetimeout'
5880 that allows you to set the number of seconds before GDB gives up trying
5881 to read from the target. The default value is 2.
5883 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5885 By default GDB will automatically keep track of objects as they are
5886 loaded and unloaded by the dynamic linker. By using the command `set
5887 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5888 when shared library events occur, thus allowing you to set breakpoints
5889 in shared libraries which are explicitly loaded by the inferior.
5891 Note this feature does not work on hpux8. On hpux9 you must link
5892 /usr/lib/end.o into your program. This feature should work
5893 automatically on hpux10.
5895 * Irix 5.x hardware watchpoint support
5897 Irix 5 configurations now support the use of hardware watchpoints.
5899 * Mips protocol "SYN garbage limit"
5901 When debugging a Mips target using the `target mips' protocol, you
5902 may set the number of characters that GDB will ignore by setting
5903 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5904 every character. The default value is 1050.
5906 * Recording and replaying remote debug sessions
5908 If you set `remotelogfile' to the name of a file, gdb will write to it
5909 a recording of a remote debug session. This recording may then be
5910 replayed back to gdb using "gdbreplay". See gdbserver/README for
5911 details. This is useful when you have a problem with GDB while doing
5912 remote debugging; you can make a recording of the session and send it
5913 to someone else, who can then recreate the problem.
5915 * Speedups for remote debugging
5917 GDB includes speedups for downloading and stepping MIPS systems using
5918 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5919 and more efficient S-record downloading.
5921 * Memory use reductions and statistics collection
5923 GDB now uses less memory and reports statistics about memory usage.
5924 Try the `maint print statistics' command, for example.
5926 *** Changes in GDB-4.15:
5928 * Psymtabs for XCOFF
5930 The symbol reader for AIX GDB now uses partial symbol tables. This
5931 can greatly improve startup time, especially for large executables.
5933 * Remote targets use caching
5935 Remote targets now use a data cache to speed up communication with the
5936 remote side. The data cache could lead to incorrect results because
5937 it doesn't know about volatile variables, thus making it impossible to
5938 debug targets which use memory mapped I/O devices. `set remotecache
5939 off' turns the the data cache off.
5941 * Remote targets may have threads
5943 The standard remote protocol now includes support for multiple threads
5944 in the target system, using new protocol commands 'H' and 'T'. See
5945 gdb/remote.c for details.
5949 If GDB is configured with `--enable-netrom', then it will include
5950 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5951 acts as though it is a bank of ROM on the target board, but you can
5952 write into it over the network. GDB's support consists only of
5953 support for fast loading into the emulated ROM; to debug, you must use
5954 another protocol, such as standard remote protocol. The usual
5955 sequence is something like
5957 target nrom <netrom-hostname>
5959 target remote <netrom-hostname>:1235
5963 GDB now includes support for the Apple Macintosh, as a host only. It
5964 may be run as either an MPW tool or as a standalone application, and
5965 it can debug through the serial port. All the usual GDB commands are
5966 available, but to the target command, you must supply "serial" as the
5967 device type instead of "/dev/ttyXX". See mpw-README in the main
5968 directory for more information on how to build. The MPW configuration
5969 scripts */mpw-config.in support only a few targets, and only the
5970 mips-idt-ecoff target has been tested.
5974 GDB configuration now uses autoconf. This is not user-visible,
5975 but does simplify configuration and building.
5979 GDB now supports hpux10.
5981 *** Changes in GDB-4.14:
5983 * New native configurations
5985 x86 FreeBSD i[345]86-*-freebsd
5986 x86 NetBSD i[345]86-*-netbsd
5987 NS32k NetBSD ns32k-*-netbsd
5988 Sparc NetBSD sparc-*-netbsd
5992 A29K VxWorks a29k-*-vxworks
5993 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5994 CPU32 EST-300 emulator m68*-*-est*
5995 PowerPC ELF powerpc-*-elf
5998 * Alpha OSF/1 support for procfs
6000 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6001 possible to attach to running processes. As the mounting of the /proc
6002 filesystem is optional on the Alpha, GDB automatically determines
6003 the availability of /proc during startup. This can lead to problems
6004 if /proc is unmounted after GDB has been started.
6006 * Arguments to user-defined commands
6008 User commands may accept up to 10 arguments separated by whitespace.
6009 Arguments are accessed within the user command via $arg0..$arg9. A
6012 print $arg0 + $arg1 + $arg2
6014 To execute the command use:
6017 Defines the command "adder" which prints the sum of its three arguments.
6018 Note the arguments are text substitutions, so they may reference variables,
6019 use complex expressions, or even perform inferior function calls.
6021 * New `if' and `while' commands
6023 This makes it possible to write more sophisticated user-defined
6024 commands. Both commands take a single argument, which is the
6025 expression to evaluate, and must be followed by the commands to
6026 execute, one per line, if the expression is nonzero, the list being
6027 terminated by the word `end'. The `if' command list may include an
6028 `else' word, which causes the following commands to be executed only
6029 if the expression is zero.
6031 * Fortran source language mode
6033 GDB now includes partial support for Fortran 77. It will recognize
6034 Fortran programs and can evaluate a subset of Fortran expressions, but
6035 variables and functions may not be handled correctly. GDB will work
6036 with G77, but does not yet know much about symbols emitted by other
6039 * Better HPUX support
6041 Most debugging facilities now work on dynamic executables for HPPAs
6042 running hpux9 or later. You can attach to running dynamically linked
6043 processes, but by default the dynamic libraries will be read-only, so
6044 for instance you won't be able to put breakpoints in them. To change
6045 that behavior do the following before running the program:
6051 This will cause the libraries to be mapped private and read-write.
6052 To revert to the normal behavior, do this:
6058 You cannot set breakpoints or examine data in the library until after
6059 the library is loaded if the function/data symbols do not have
6062 GDB can now also read debug symbols produced by the HP C compiler on
6063 HPPAs (sorry, no C++, Fortran or 68k support).
6065 * Target byte order now dynamically selectable
6067 You can choose which byte order to use with a target system, via the
6068 commands "set endian big" and "set endian little", and you can see the
6069 current setting by using "show endian". You can also give the command
6070 "set endian auto", in which case GDB will use the byte order
6071 associated with the executable. Currently, only embedded MIPS
6072 configurations support dynamic selection of target byte order.
6074 * New DOS host serial code
6076 This version uses DPMI interrupts to handle buffered I/O, so you
6077 no longer need to run asynctsr when debugging boards connected to
6080 *** Changes in GDB-4.13:
6082 * New "complete" command
6084 This lists all the possible completions for the rest of the line, if it
6085 were to be given as a command itself. This is intended for use by emacs.
6087 * Trailing space optional in prompt
6089 "set prompt" no longer adds a space for you after the prompt you set. This
6090 allows you to set a prompt which ends in a space or one that does not.
6092 * Breakpoint hit counts
6094 "info break" now displays a count of the number of times the breakpoint
6095 has been hit. This is especially useful in conjunction with "ignore"; you
6096 can ignore a large number of breakpoint hits, look at the breakpoint info
6097 to see how many times the breakpoint was hit, then run again, ignoring one
6098 less than that number, and this will get you quickly to the last hit of
6101 * Ability to stop printing at NULL character
6103 "set print null-stop" will cause GDB to stop printing the characters of
6104 an array when the first NULL is encountered. This is useful when large
6105 arrays actually contain only short strings.
6107 * Shared library breakpoints
6109 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6110 breakpoints in shared libraries before the executable is run.
6112 * Hardware watchpoints
6114 There is a new hardware breakpoint for the watch command for sparclite
6115 targets. See gdb/sparclite/hw_breakpoint.note.
6117 Hardware watchpoints are also now supported under GNU/Linux.
6121 Annotations have been added. These are for use with graphical interfaces,
6122 and are still experimental. Currently only gdba.el uses these.
6124 * Improved Irix 5 support
6126 GDB now works properly with Irix 5.2.
6128 * Improved HPPA support
6130 GDB now works properly with the latest GCC and GAS.
6132 * New native configurations
6134 Sequent PTX4 i[34]86-sequent-ptx4
6135 HPPA running OSF/1 hppa*-*-osf*
6136 Atari TT running SVR4 m68*-*-sysv4*
6137 RS/6000 LynxOS rs6000-*-lynxos*
6141 OS/9000 i[34]86-*-os9k
6142 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6145 * Hitachi SH7000 and E7000-PC ICE support
6147 There is now support for communicating with the Hitachi E7000-PC ICE.
6148 This is available automatically when GDB is configured for the SH.
6152 As usual, a variety of small fixes and improvements, both generic
6153 and configuration-specific. See the ChangeLog for more detail.
6155 *** Changes in GDB-4.12:
6157 * Irix 5 is now supported
6161 GDB-4.12 on the HPPA has a number of changes which make it unable
6162 to debug the output from the currently released versions of GCC and
6163 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6164 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6165 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6168 *** Changes in GDB-4.11:
6170 * User visible changes:
6174 The "set remotedebug" option is now consistent between the mips remote
6175 target, remote targets using the gdb-specific protocol, UDI (AMD's
6176 debug protocol for the 29k) and the 88k bug monitor. It is now an
6177 integer specifying a debug level (normally 0 or 1, but 2 means more
6178 debugging info for the mips target).
6180 * DEC Alpha native support
6182 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6183 debug info, but GDB works fairly well with the DEC compiler and should
6184 work with a future GCC release. See the README file for a few
6185 Alpha-specific notes.
6187 * Preliminary thread implementation
6189 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6191 * LynxOS native and target support for 386
6193 This release has been hosted on LynxOS 2.2, and also can be configured
6194 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6197 * Improvements in C++ mangling/demangling.
6199 This release has much better g++ debugging, specifically in name
6200 mangling/demangling, virtual function calls, print virtual table,
6201 call methods, ...etc.
6203 *** Changes in GDB-4.10:
6205 * User visible changes:
6207 Remote debugging using the GDB-specific (`target remote') protocol now
6208 supports the `load' command. This is only useful if you have some
6209 other way of getting the stub to the target system, and you can put it
6210 somewhere in memory where it won't get clobbered by the download.
6212 Filename completion now works.
6214 When run under emacs mode, the "info line" command now causes the
6215 arrow to point to the line specified. Also, "info line" prints
6216 addresses in symbolic form (as well as hex).
6218 All vxworks based targets now support a user settable option, called
6219 vxworks-timeout. This option represents the number of seconds gdb
6220 should wait for responses to rpc's. You might want to use this if
6221 your vxworks target is, perhaps, a slow software simulator or happens
6222 to be on the far side of a thin network line.
6226 This release contains support for using a DEC alpha as a GDB host for
6227 cross debugging. Native alpha debugging is not supported yet.
6230 *** Changes in GDB-4.9:
6234 This is the first GDB release which is accompanied by a matching testsuite.
6235 The testsuite requires installation of dejagnu, which should be available
6236 via ftp from most sites that carry GNU software.
6240 'Cfront' style demangling has had its name changed to 'ARM' style, to
6241 emphasize that it was written from the specifications in the C++ Annotated
6242 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6243 disclaimers, it still generated too much confusion with users attempting to
6244 use gdb with AT&T cfront.
6248 GDB now uses a standard remote interface to a simulator library.
6249 So far, the library contains simulators for the Zilog Z8001/2, the
6250 Hitachi H8/300, H8/500 and Super-H.
6252 * New targets supported
6254 H8/300 simulator h8300-hitachi-hms or h8300hms
6255 H8/500 simulator h8500-hitachi-hms or h8500hms
6256 SH simulator sh-hitachi-hms or sh
6257 Z8000 simulator z8k-zilog-none or z8ksim
6258 IDT MIPS board over serial line mips-idt-ecoff
6260 Cross-debugging to GO32 targets is supported. It requires a custom
6261 version of the i386-stub.c module which is integrated with the
6262 GO32 memory extender.
6264 * New remote protocols
6266 MIPS remote debugging protocol.
6268 * New source languages supported
6270 This version includes preliminary support for Chill, a Pascal like language
6271 used by telecommunications companies. Chill support is also being integrated
6272 into the GNU compiler, but we don't know when it will be publically available.
6275 *** Changes in GDB-4.8:
6277 * HP Precision Architecture supported
6279 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6280 version of this support was available as a set of patches from the
6281 University of Utah. GDB does not support debugging of programs
6282 compiled with the HP compiler, because HP will not document their file
6283 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6284 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6286 Many problems in the preliminary version have been fixed.
6288 * Faster and better demangling
6290 We have improved template demangling and fixed numerous bugs in the GNU style
6291 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6292 character types (wchar_t) are now supported. Demangling of each symbol is now
6293 only done once, and is cached when the symbol table for a file is read in.
6294 This results in a small increase in memory usage for C programs, a moderate
6295 increase in memory usage for C++ programs, and a fantastic speedup in
6298 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6299 from the specifications in the Annotated Reference Manual, which AT&T's
6300 compiler does not actually implement.
6302 * G++ multiple inheritance compiler problem
6304 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6305 inheritance lattices was reworked to properly discover ambiguities. We
6306 recently found an example which causes this new algorithm to fail in a
6307 very subtle way, producing bad debug information for those classes.
6308 The file 'gcc.patch' (in this directory) can be applied to gcc to
6309 circumvent the problem. A future GCC release will contain a complete
6312 The previous G++ debug info problem (mentioned below for the gdb-4.7
6313 release) is fixed in gcc version 2.3.2.
6315 * Improved configure script
6317 The `configure' script will now attempt to guess your system type if
6318 you don't supply a host system type. The old scheme of supplying a
6319 host system triplet is preferable over using this. All the magic is
6320 done in the new `config.guess' script. Examine it for details.
6322 We have also brought our configure script much more in line with the FSF's
6323 version. It now supports the --with-xxx options. In particular,
6324 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6325 The resulting GDB will not be able to read arbitrary object file formats --
6326 only the format ``expected'' to be used on the configured target system.
6327 We hope to make this the default in a future release.
6329 * Documentation improvements
6331 There's new internal documentation on how to modify GDB, and how to
6332 produce clean changes to the code. We implore people to read it
6333 before submitting changes.
6335 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6336 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6337 `info' files are also provided. To build `info' files from scratch,
6338 you will need the latest `makeinfo' release, which will be available in
6339 a future texinfo-X.Y release.
6341 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6342 We're not sure exactly which versions have this problem, but it has
6343 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6344 or better. If that isn't possible, there is a patch in
6345 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6346 around this problem.
6350 GDB now supports array constants that can be used in expressions typed in by
6351 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6352 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6355 The new directory `gdb/sparclite' contains a program that demonstrates
6356 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6358 * New native hosts supported
6360 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6361 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6363 * New targets supported
6365 AMD 29k family via UDI a29k-amd-udi or udi29k
6367 * New file formats supported
6369 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6370 HPUX core files, and SCO 3.2v2 core files.
6374 Attaching to processes now works again; thanks for the many bug reports.
6376 We have also stomped on a bunch of core dumps caused by
6377 printf_filtered("%s") problems.
6379 We eliminated a copyright problem on the rpc and ptrace header files
6380 for VxWorks, which was discovered at the last minute during the 4.7
6381 release. You should now be able to build a VxWorks GDB.
6383 You can now interrupt gdb while an attached process is running. This
6384 will cause the attached process to stop, and give control back to GDB.
6386 We fixed problems caused by using too many file descriptors
6387 for reading symbols from object files and libraries. This was
6388 especially a problem for programs that used many (~100) shared
6391 The `step' command now only enters a subroutine if there is line number
6392 information for the subroutine. Otherwise it acts like the `next'
6393 command. Previously, `step' would enter subroutines if there was
6394 any debugging information about the routine. This avoids problems
6395 when using `cc -g1' on MIPS machines.
6397 * Internal improvements
6399 GDB's internal interfaces have been improved to make it easier to support
6400 debugging of multiple languages in the future.
6402 GDB now uses a common structure for symbol information internally.
6403 Minimal symbols (derived from linkage symbols in object files), partial
6404 symbols (from a quick scan of debug information), and full symbols
6405 contain a common subset of information, making it easier to write
6406 shared code that handles any of them.
6408 * New command line options
6410 We now accept --silent as an alias for --quiet.
6414 The memory-mapped-malloc library is now licensed under the GNU Library
6415 General Public License.
6417 *** Changes in GDB-4.7:
6419 * Host/native/target split
6421 GDB has had some major internal surgery to untangle the support for
6422 hosts and remote targets. Now, when you configure GDB for a remote
6423 target, it will no longer load in all of the support for debugging
6424 local programs on the host. When fully completed and tested, this will
6425 ensure that arbitrary host/target combinations are possible.
6427 The primary conceptual shift is to separate the non-portable code in
6428 GDB into three categories. Host specific code is required any time GDB
6429 is compiled on that host, regardless of the target. Target specific
6430 code relates to the peculiarities of the target, but can be compiled on
6431 any host. Native specific code is everything else: it can only be
6432 built when the host and target are the same system. Child process
6433 handling and core file support are two common `native' examples.
6435 GDB's use of /proc for controlling Unix child processes is now cleaner.
6436 It has been split out into a single module under the `target_ops' vector,
6437 plus two native-dependent functions for each system that uses /proc.
6439 * New hosts supported
6441 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6442 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6443 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6445 * New targets supported
6447 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6448 68030 and CPU32 m68030-*-*, m68332-*-*
6450 * New native hosts supported
6452 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6453 (386bsd is not well tested yet)
6454 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6456 * New file formats supported
6458 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6459 supports reading of `a.out.adobe' object files, which are an a.out
6460 format extended with minimal information about multiple sections.
6464 `show copying' is the same as the old `info copying'.
6465 `show warranty' is the same as `info warrantee'.
6466 These were renamed for consistency. The old commands continue to work.
6468 `info handle' is a new alias for `info signals'.
6470 You can now define pre-command hooks, which attach arbitrary command
6471 scripts to any command. The commands in the hook will be executed
6472 prior to the user's command. You can also create a hook which will be
6473 executed whenever the program stops. See gdb.texinfo.
6477 We now deal with Cfront style name mangling, and can even extract type
6478 info from mangled symbols. GDB can automatically figure out which
6479 symbol mangling style your C++ compiler uses.
6481 Calling of methods and virtual functions has been improved as well.
6485 The crash that occured when debugging Sun Ansi-C compiled binaries is
6486 fixed. This was due to mishandling of the extra N_SO stabs output
6489 We also finally got Ultrix 4.2 running in house, and fixed core file
6490 support, with help from a dozen people on the net.
6492 John M. Farrell discovered that the reason that single-stepping was so
6493 slow on all of the Mips based platforms (primarily SGI and DEC) was
6494 that we were trying to demangle and lookup a symbol used for internal
6495 purposes on every instruction that was being stepped through. Changing
6496 the name of that symbol so that it couldn't be mistaken for a C++
6497 mangled symbol sped things up a great deal.
6499 Rich Pixley sped up symbol lookups in general by getting much smarter
6500 about when C++ symbol mangling is necessary. This should make symbol
6501 completion (TAB on the command line) much faster. It's not as fast as
6502 we'd like, but it's significantly faster than gdb-4.6.
6506 A new user controllable variable 'call_scratch_address' can
6507 specify the location of a scratch area to be used when GDB
6508 calls a function in the target. This is necessary because the
6509 usual method of putting the scratch area on the stack does not work
6510 in systems that have separate instruction and data spaces.
6512 We integrated changes to support the 29k UDI (Universal Debugger
6513 Interface), but discovered at the last minute that we didn't have all
6514 of the appropriate copyright paperwork. We are working with AMD to
6515 resolve this, and hope to have it available soon.
6519 We have sped up the remote serial line protocol, especially for targets
6520 with lots of registers. It now supports a new `expedited status' ('T')
6521 message which can be used in place of the existing 'S' status message.
6522 This allows the remote stub to send only the registers that GDB
6523 needs to make a quick decision about single-stepping or conditional
6524 breakpoints, eliminating the need to fetch the entire register set for
6525 each instruction being stepped through.
6527 The GDB remote serial protocol now implements a write-through cache for
6528 registers, only re-reading the registers if the target has run.
6530 There is also a new remote serial stub for SPARC processors. You can
6531 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6532 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6533 processor with a serial port.
6537 Configure.in files have become much easier to read and modify. A new
6538 `table driven' format makes it more obvious what configurations are
6539 supported, and what files each one uses.
6543 There is a new opcodes library which will eventually contain all of the
6544 disassembly routines and opcode tables. At present, it only contains
6545 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6546 disassembler (binutils/objdump) to share these routines.
6548 The libiberty library is now copylefted under the GNU Library General
6549 Public License. This allows more liberal use, and was done so libg++
6550 can use it. This makes no difference to GDB, since the Library License
6551 grants all the rights from the General Public License.
6555 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6556 reference to the stabs symbol info used by the debugger. It is (as far
6557 as we know) the only published document on this fascinating topic. We
6558 encourage you to read it, compare it to the stabs information on your
6559 system, and send improvements on the document in general (to
6560 bug-gdb@prep.ai.mit.edu).
6562 And, of course, many bugs have been fixed.
6565 *** Changes in GDB-4.6:
6567 * Better support for C++ function names
6569 GDB now accepts as input the "demangled form" of C++ overloaded function
6570 names and member function names, and can do command completion on such names
6571 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6572 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6573 Make use of command completion, it is your friend.
6575 GDB also now accepts a variety of C++ mangled symbol formats. They are
6576 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6577 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6578 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6579 for the list of formats.
6581 * G++ symbol mangling problem
6583 Recent versions of gcc have a bug in how they emit debugging information for
6584 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6585 directory) can be applied to gcc to fix the problem. Alternatively, if you
6586 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6587 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6588 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6591 * New 'maintenance' command
6593 All of the commands related to hacking GDB internals have been moved out of
6594 the main command set, and now live behind the 'maintenance' command. This
6595 can also be abbreviated as 'mt'. The following changes were made:
6597 dump-me -> maintenance dump-me
6598 info all-breakpoints -> maintenance info breakpoints
6599 printmsyms -> maintenance print msyms
6600 printobjfiles -> maintenance print objfiles
6601 printpsyms -> maintenance print psymbols
6602 printsyms -> maintenance print symbols
6604 The following commands are new:
6606 maintenance demangle Call internal GDB demangler routine to
6607 demangle a C++ link name and prints the result.
6608 maintenance print type Print a type chain for a given symbol
6610 * Change to .gdbinit file processing
6612 We now read the $HOME/.gdbinit file before processing the argv arguments
6613 (e.g. reading symbol files or core files). This allows global parameters to
6614 be set, which will apply during the symbol reading. The ./.gdbinit is still
6615 read after argv processing.
6617 * New hosts supported
6619 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6621 GNU/Linux support i386-unknown-linux or linux
6623 We are also including code to support the HP/PA running BSD and HPUX. This
6624 is almost guaranteed not to work, as we didn't have time to test or build it
6625 for this release. We are including it so that the more adventurous (or
6626 masochistic) of you can play with it. We also had major problems with the
6627 fact that the compiler that we got from HP doesn't support the -g option.
6630 * New targets supported
6632 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6634 * More smarts about finding #include files
6636 GDB now remembers the compilation directory for all include files, and for
6637 all files from which C is generated (like yacc and lex sources). This
6638 greatly improves GDB's ability to find yacc/lex sources, and include files,
6639 especially if you are debugging your program from a directory different from
6640 the one that contains your sources.
6642 We also fixed a bug which caused difficulty with listing and setting
6643 breakpoints in include files which contain C code. (In the past, you had to
6644 try twice in order to list an include file that you hadn't looked at before.)
6646 * Interesting infernals change
6648 GDB now deals with arbitrary numbers of sections, where the symbols for each
6649 section must be relocated relative to that section's landing place in the
6650 target's address space. This work was needed to support ELF with embedded
6651 stabs used by Solaris-2.0.
6653 * Bug fixes (of course!)
6655 There have been loads of fixes for the following things:
6656 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6657 i960, stabs, DOS(GO32), procfs, etc...
6659 See the ChangeLog for details.
6661 *** Changes in GDB-4.5:
6663 * New machines supported (host and target)
6665 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6667 SGI Irix-4.x mips-sgi-irix4 or iris4
6669 * New malloc package
6671 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6672 Mmalloc is capable of handling mutiple heaps of memory. It is also
6673 capable of saving a heap to a file, and then mapping it back in later.
6674 This can be used to greatly speedup the startup of GDB by using a
6675 pre-parsed symbol table which lives in a mmalloc managed heap. For
6676 more details, please read mmalloc/mmalloc.texi.
6680 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6681 'help info proc' for details.
6683 * MIPS ecoff symbol table format
6685 The code that reads MIPS symbol table format is now supported on all hosts.
6686 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6689 * File name changes for MS-DOS
6691 Many files in the config directories have been renamed to make it easier to
6692 support GDB on MS-DOSe systems (which have very restrictive file name
6693 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6694 environment) is close to working but has some remaining problems. Note
6695 that debugging of DOS programs is not supported, due to limitations
6696 in the ``operating system'', but it can be used to host cross-debugging.
6698 * Cross byte order fixes
6700 Many fixes have been made to support cross debugging of Sparc and MIPS
6701 targets from hosts whose byte order differs.
6703 * New -mapped and -readnow options
6705 If memory-mapped files are available on your system through the 'mmap'
6706 system call, you can use the -mapped option on the `file' or
6707 `symbol-file' commands to cause GDB to write the symbols from your
6708 program into a reusable file. If the program you are debugging is
6709 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6710 Future GDB debugging sessions will notice the presence of this file,
6711 and will quickly map in symbol information from it, rather than reading
6712 the symbol table from the executable program. Using the '-mapped'
6713 option in a GDB `file' or `symbol-file' command has the same effect as
6714 starting GDB with the '-mapped' command-line option.
6716 You can cause GDB to read the entire symbol table immediately by using
6717 the '-readnow' option with any of the commands that load symbol table
6718 information (or on the GDB command line). This makes the command
6719 slower, but makes future operations faster.
6721 The -mapped and -readnow options are typically combined in order to
6722 build a `fred.syms' file that contains complete symbol information.
6723 A simple GDB invocation to do nothing but build a `.syms' file for future
6726 gdb -batch -nx -mapped -readnow programname
6728 The `.syms' file is specific to the host machine on which GDB is run.
6729 It holds an exact image of GDB's internal symbol table. It cannot be
6730 shared across multiple host platforms.
6732 * longjmp() handling
6734 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6735 siglongjmp() without losing control. This feature has not yet been ported to
6736 all systems. It currently works on many 386 platforms, all MIPS-based
6737 platforms (SGI, DECstation, etc), and Sun3/4.
6741 Preliminary work has been put in to support the new Solaris OS from Sun. At
6742 this time, it can control and debug processes, but it is not capable of
6747 As always, many many bug fixes. The major areas were with g++, and mipsread.
6748 People using the MIPS-based platforms should experience fewer mysterious
6749 crashes and trashed symbol tables.
6751 *** Changes in GDB-4.4:
6753 * New machines supported (host and target)
6755 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6757 BSD Reno on Vax vax-dec-bsd
6758 Ultrix on Vax vax-dec-ultrix
6760 * New machines supported (target)
6762 AMD 29000 embedded, using EBMON a29k-none-none
6766 GDB continues to improve its handling of C++. `References' work better.
6767 The demangler has also been improved, and now deals with symbols mangled as
6768 per the Annotated C++ Reference Guide.
6770 GDB also now handles `stabs' symbol information embedded in MIPS
6771 `ecoff' symbol tables. Since the ecoff format was not easily
6772 extensible to handle new languages such as C++, this appeared to be a
6773 good way to put C++ debugging info into MIPS binaries. This option
6774 will be supported in the GNU C compiler, version 2, when it is
6777 * New features for SVR4
6779 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6780 shared libraries. Debugging dynamically linked programs should present
6781 only minor differences from debugging statically linked programs.
6783 The `info proc' command will print out information about any process
6784 on an SVR4 system (including the one you are debugging). At the moment,
6785 it prints the address mappings of the process.
6787 If you bring up GDB on another SVR4 system, please send mail to
6788 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6790 * Better dynamic linking support in SunOS
6792 Reading symbols from shared libraries which contain debugging symbols
6793 now works properly. However, there remain issues such as automatic
6794 skipping of `transfer vector' code during function calls, which
6795 make it harder to debug code in a shared library, than to debug the
6796 same code linked statically.
6800 GDB is now using the latest `getopt' routines from the FSF. This
6801 version accepts the -- prefix for options with long names. GDB will
6802 continue to accept the old forms (-option and +option) as well.
6803 Various single letter abbreviations for options have been explicity
6804 added to the option table so that they won't get overshadowed in the
6805 future by other options that begin with the same letter.
6809 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6810 Many assorted bugs have been handled. Many more remain to be handled.
6811 See the various ChangeLog files (primarily in gdb and bfd) for details.
6814 *** Changes in GDB-4.3:
6816 * New machines supported (host and target)
6818 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6819 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6820 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6822 * Almost SCO Unix support
6824 We had hoped to support:
6825 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6826 (except for core file support), but we discovered very late in the release
6827 that it has problems with process groups that render gdb unusable. Sorry
6828 about that. I encourage people to fix it and post the fixes.
6830 * Preliminary ELF and DWARF support
6832 GDB can read ELF object files on System V Release 4, and can handle
6833 debugging records for C, in DWARF format, in ELF files. This support
6834 is preliminary. If you bring up GDB on another SVR4 system, please
6835 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6840 GDB now uses the latest `readline' library. One user-visible change
6841 is that two tabs will list possible command completions, which previously
6842 required typing M-? (meta-question mark, or ESC ?).
6846 The `stepi' bug that many of you noticed has been squashed.
6847 Many bugs in C++ have been handled. Many more remain to be handled.
6848 See the various ChangeLog files (primarily in gdb and bfd) for details.
6850 * State of the MIPS world (in case you wondered):
6852 GDB can understand the symbol tables emitted by the compilers
6853 supplied by most vendors of MIPS-based machines, including DEC. These
6854 symbol tables are in a format that essentially nobody else uses.
6856 Some versions of gcc come with an assembler post-processor called
6857 mips-tfile. This program is required if you want to do source-level
6858 debugging of gcc-compiled programs. I believe FSF does not ship
6859 mips-tfile with gcc version 1, but it will eventually come with gcc
6862 Debugging of g++ output remains a problem. g++ version 1.xx does not
6863 really support it at all. (If you're lucky, you should be able to get
6864 line numbers and stack traces to work, but no parameters or local
6865 variables.) With some work it should be possible to improve the
6868 When gcc version 2 is released, you will have somewhat better luck.
6869 However, even then you will get confusing results for inheritance and
6872 We will eventually provide full debugging of g++ output on
6873 DECstations. This will probably involve some kind of stabs-in-ecoff
6874 encapulation, but the details have not been worked out yet.
6877 *** Changes in GDB-4.2:
6879 * Improved configuration
6881 Only one copy of `configure' exists now, and it is not self-modifying.
6882 Porting BFD is simpler.
6886 The `step' and `next' commands now only stop at the first instruction
6887 of a source line. This prevents the multiple stops that used to occur
6888 in switch statements, for-loops, etc. `Step' continues to stop if a
6889 function that has debugging information is called within the line.
6893 Lots of small bugs fixed. More remain.
6895 * New host supported (not target)
6897 Intel 386 PC clone running Mach i386-none-mach
6900 *** Changes in GDB-4.1:
6902 * Multiple source language support
6904 GDB now has internal scaffolding to handle several source languages.
6905 It determines the type of each source file from its filename extension,
6906 and will switch expression parsing and number formatting to match the
6907 language of the function in the currently selected stack frame.
6908 You can also specifically set the language to be used, with
6909 `set language c' or `set language modula-2'.
6913 GDB now has preliminary support for the GNU Modula-2 compiler,
6914 currently under development at the State University of New York at
6915 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6916 continue through the fall of 1991 and into 1992.
6918 Other Modula-2 compilers are currently not supported, and attempting to
6919 debug programs compiled with them will likely result in an error as the
6920 symbol table is read. Feel free to work on it, though!
6922 There are hooks in GDB for strict type checking and range checking,
6923 in the `Modula-2 philosophy', but they do not currently work.
6927 GDB can now write to executable and core files (e.g. patch
6928 a variable's value). You must turn this switch on, specify
6929 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6930 by assigning a new value to a variable. Modifications take
6933 * Automatic SunOS shared library reading
6935 When you run your program, GDB automatically determines where its
6936 shared libraries (if any) have been loaded, and reads their symbols.
6937 The `share' command is no longer needed. This also works when
6938 examining core files.
6942 You can specify the number of lines that the `list' command shows.
6945 * New machines supported (host and target)
6947 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6948 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6949 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6951 * New hosts supported (not targets)
6953 IBM RT/PC: romp-ibm-aix or rtpc
6955 * New targets supported (not hosts)
6957 AMD 29000 embedded with COFF a29k-none-coff
6958 AMD 29000 embedded with a.out a29k-none-aout
6959 Ultracomputer remote kernel debug a29k-nyu-kern
6961 * New remote interfaces
6967 *** Changes in GDB-4.0:
6971 Wide output is wrapped at good places to make the output more readable.
6973 Gdb now supports cross-debugging from a host machine of one type to a
6974 target machine of another type. Communication with the target system
6975 is over serial lines. The ``target'' command handles connecting to the
6976 remote system; the ``load'' command will download a program into the
6977 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6978 also supports debugging of realtime processes running under VxWorks,
6979 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6980 stub on the target system.
6982 New CPUs supported include the AMD 29000 and Intel 960.
6984 GDB now reads object files and symbol tables via a ``binary file''
6985 library, which allows a single copy of GDB to debug programs of multiple
6986 object file types such as a.out and coff.
6988 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6989 refcard.dvi and refcard.ps are available to format it).
6992 * Control-Variable user interface simplified
6994 All variables that control the operation of the debugger can be set
6995 by the ``set'' command, and displayed by the ``show'' command.
6997 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6998 ``Show prompt'' produces the response:
6999 Gdb's prompt is new-gdb=>.
7001 What follows are the NEW set commands. The command ``help set'' will
7002 print a complete list of old and new set commands. ``help set FOO''
7003 will give a longer description of the variable FOO. ``show'' will show
7004 all of the variable descriptions and their current settings.
7006 confirm on/off: Enables warning questions for operations that are
7007 hard to recover from, e.g. rerunning the program while
7008 it is already running. Default is ON.
7010 editing on/off: Enables EMACS style command line editing
7011 of input. Previous lines can be recalled with
7012 control-P, the current line can be edited with control-B,
7013 you can search for commands with control-R, etc.
7016 history filename NAME: NAME is where the gdb command history
7017 will be stored. The default is .gdb_history,
7018 or the value of the environment variable
7021 history size N: The size, in commands, of the command history. The
7022 default is 256, or the value of the environment variable
7025 history save on/off: If this value is set to ON, the history file will
7026 be saved after exiting gdb. If set to OFF, the
7027 file will not be saved. The default is OFF.
7029 history expansion on/off: If this value is set to ON, then csh-like
7030 history expansion will be performed on
7031 command line input. The default is OFF.
7033 radix N: Sets the default radix for input and output. It can be set
7034 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7035 in the current radix, so "set radix 10" is always a no-op.
7037 height N: This integer value is the number of lines on a page. Default
7038 is 24, the current `stty rows'' setting, or the ``li#''
7039 setting from the termcap entry matching the environment
7042 width N: This integer value is the number of characters on a line.
7043 Default is 80, the current `stty cols'' setting, or the ``co#''
7044 setting from the termcap entry matching the environment
7047 Note: ``set screensize'' is obsolete. Use ``set height'' and
7048 ``set width'' instead.
7050 print address on/off: Print memory addresses in various command displays,
7051 such as stack traces and structure values. Gdb looks
7052 more ``symbolic'' if you turn this off; it looks more
7053 ``machine level'' with it on. Default is ON.
7055 print array on/off: Prettyprint arrays. New convenient format! Default
7058 print demangle on/off: Print C++ symbols in "source" form if on,
7061 print asm-demangle on/off: Same, for assembler level printouts
7064 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7067 * Support for Epoch Environment.
7069 The epoch environment is a version of Emacs v18 with windowing. One
7070 new command, ``inspect'', is identical to ``print'', except that if you
7071 are running in the epoch environment, the value is printed in its own
7075 * Support for Shared Libraries
7077 GDB can now debug programs and core files that use SunOS shared libraries.
7078 Symbols from a shared library cannot be referenced
7079 before the shared library has been linked with the program (this
7080 happens after you type ``run'' and before the function main() is entered).
7081 At any time after this linking (including when examining core files
7082 from dynamically linked programs), gdb reads the symbols from each
7083 shared library when you type the ``sharedlibrary'' command.
7084 It can be abbreviated ``share''.
7086 sharedlibrary REGEXP: Load shared object library symbols for files
7087 matching a unix regular expression. No argument
7088 indicates to load symbols for all shared libraries.
7090 info sharedlibrary: Status of loaded shared libraries.
7095 A watchpoint stops execution of a program whenever the value of an
7096 expression changes. Checking for this slows down execution
7097 tremendously whenever you are in the scope of the expression, but is
7098 quite useful for catching tough ``bit-spreader'' or pointer misuse
7099 problems. Some machines such as the 386 have hardware for doing this
7100 more quickly, and future versions of gdb will use this hardware.
7102 watch EXP: Set a watchpoint (breakpoint) for an expression.
7104 info watchpoints: Information about your watchpoints.
7106 delete N: Deletes watchpoint number N (same as breakpoints).
7107 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7108 enable N: Re-enables watchpoint number N (same as breakpoints).
7111 * C++ multiple inheritance
7113 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7116 * C++ exception handling
7118 Gdb now supports limited C++ exception handling. Besides the existing
7119 ability to breakpoint on an exception handler, gdb can breakpoint on
7120 the raising of an exception (before the stack is peeled back to the
7123 catch FOO: If there is a FOO exception handler in the dynamic scope,
7124 set a breakpoint to catch exceptions which may be raised there.
7125 Multiple exceptions (``catch foo bar baz'') may be caught.
7127 info catch: Lists all exceptions which may be caught in the
7128 current stack frame.
7131 * Minor command changes
7133 The command ``call func (arg, arg, ...)'' now acts like the print
7134 command, except it does not print or save a value if the function's result
7135 is void. This is similar to dbx usage.
7137 The ``up'' and ``down'' commands now always print the frame they end up
7138 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7139 frames without printing.
7141 * New directory command
7143 'dir' now adds directories to the FRONT of the source search path.
7144 The path starts off empty. Source files that contain debug information
7145 about the directory in which they were compiled can be found even
7146 with an empty path; Sun CC and GCC include this information. If GDB can't
7147 find your source file in the current directory, type "dir .".
7149 * Configuring GDB for compilation
7151 For normal use, type ``./configure host''. See README or gdb.texinfo
7154 GDB now handles cross debugging. If you are remotely debugging between
7155 two different machines, type ``./configure host -target=targ''.
7156 Host is the machine where GDB will run; targ is the machine
7157 where the program that you are debugging will run.