1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
7 can be passed using the '[ADDRESS]:PORT' notation, or the regular
10 * DWARF index cache: GDB can now automatically save indices of DWARF
11 symbols on disk to speed up further loading of the same binaries.
15 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
16 Apply a command to some frames.
17 FLAG arguments allow to control what output to produce and how to handle
18 errors raised when applying COMMAND to a frame.
21 Apply a command to all threads (ignoring errors and empty output).
22 Shortcut for 'thread apply all -s COMMAND'.
25 Apply a command to all frames (ignoring errors and empty output).
26 Shortcut for 'frame apply all -s COMMAND'.
29 Apply a command to all frames of all threads (ignoring errors and empty
31 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
33 maint set dwarf unwinders (on|off)
34 maint show dwarf unwinders
35 Control whether DWARF unwinders can be used.
39 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
40 The 'thread apply' command accepts new FLAG arguments.
41 FLAG arguments allow to control what output to produce and how to handle
42 errors raised when applying COMMAND to a thread.
44 *** Changes in GDB 8.2
46 * The 'set disassembler-options' command now supports specifying options
49 * The 'symbol-file' command now accepts an '-o' option to add a relative
50 offset to all sections.
52 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
53 a relative offset to all sections, but it allows to override the load
54 address of individual sections using '-s'.
56 * The 'add-symbol-file' command no longer requires the second argument
57 (address of the text section).
59 * The endianness used with the 'set endian auto' mode in the absence of
60 an executable selected for debugging is now the last endianness chosen
61 either by one of the 'set endian big' and 'set endian little' commands
62 or by inferring from the last executable used, rather than the startup
65 * The pager now allows a "c" response, meaning to disable the pager
66 for the rest of the current command.
68 * The commands 'info variables/functions/types' now show the source line
69 numbers of symbol definitions when available.
71 * 'info proc' now works on running processes on FreeBSD systems and core
72 files created on FreeBSD systems.
74 * C expressions can now use _Alignof, and C++ expressions can now use
81 Control display of debugging info regarding the FreeBSD native target.
83 set|show varsize-limit
84 This new setting allows the user to control the maximum size of Ada
85 objects being printed when those objects have a variable type,
86 instead of that maximum size being hardcoded to 65536 bytes.
88 set|show record btrace cpu
89 Controls the processor to be used for enabling errata workarounds for
92 maint check libthread-db
93 Run integrity checks on the current inferior's thread debugging
96 maint set check-libthread-db (on|off)
97 maint show check-libthread-db
98 Control whether to run integrity checks on inferior specific thread
99 debugging libraries as they are loaded. The default is not to
104 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
106 ** The commands attached to a breakpoint can be set by assigning to
107 the breakpoint's "commands" field.
109 ** gdb.execute can now execute multi-line gdb commands.
111 ** The new functions gdb.convenience_variable and
112 gdb.set_convenience_variable can be used to get and set the value
113 of convenience variables.
115 ** A gdb.Parameter will no longer print the "set" help text on an
116 ordinary "set"; instead by default a "set" will be silent unless
117 the get_set_string method returns a non-empty string.
121 RiscV ELF riscv*-*-elf
123 * Removed targets and native configurations
125 m88k running OpenBSD m88*-*-openbsd*
126 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
127 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
128 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
130 * Aarch64/Linux hardware watchpoints improvements
132 Hardware watchpoints on unaligned addresses are now properly
133 supported when running Linux kernel 4.10 or higher: read and access
134 watchpoints are no longer spuriously missed, and all watchpoints
135 lengths between 1 and 8 bytes are supported. On older kernels,
136 watchpoints set on unaligned addresses are no longer missed, with
137 the tradeoff that there is a possibility of false hits being
142 --enable-codesign=CERT
143 This can be used to invoke "codesign -s CERT" after building gdb.
144 This option is useful on macOS, where code signing is required for
145 gdb to work properly.
147 --disable-gdbcli has been removed
148 This is now silently accepted, but does nothing.
150 *** Changes in GDB 8.1
152 * GDB now supports dynamically creating arbitrary register groups specified
153 in XML target descriptions. This allows for finer grain grouping of
154 registers on systems with a large amount of registers.
156 * The 'ptype' command now accepts a '/o' flag, which prints the
157 offsets and sizes of fields in a struct, like the pahole(1) tool.
159 * New "--readnever" command line option instructs GDB to not read each
160 symbol file's symbolic debug information. This makes startup faster
161 but at the expense of not being able to perform symbolic debugging.
162 This option is intended for use cases where symbolic debugging will
163 not be used, e.g., when you only need to dump the debuggee's core.
165 * GDB now uses the GNU MPFR library, if available, to emulate target
166 floating-point arithmetic during expression evaluation when the target
167 uses different floating-point formats than the host. At least version
168 3.1 of GNU MPFR is required.
170 * GDB now supports access to the guarded-storage-control registers and the
171 software-based guarded-storage broadcast control registers on IBM z14.
173 * On Unix systems, GDB now supports transmitting environment variables
174 that are to be set or unset to GDBserver. These variables will
175 affect the environment to be passed to the remote inferior.
177 To inform GDB of environment variables that are to be transmitted to
178 GDBserver, use the "set environment" command. Only user set
179 environment variables are sent to GDBserver.
181 To inform GDB of environment variables that are to be unset before
182 the remote inferior is started by the GDBserver, use the "unset
183 environment" command.
185 * Completion improvements
187 ** GDB can now complete function parameters in linespecs and
188 explicit locations without quoting. When setting breakpoints,
189 quoting around functions names to help with TAB-completion is
190 generally no longer necessary. For example, this now completes
193 (gdb) b function(in[TAB]
194 (gdb) b function(int)
196 Related, GDB is no longer confused with completing functions in
197 C++ anonymous namespaces:
200 (gdb) b (anonymous namespace)::[TAB][TAB]
201 (anonymous namespace)::a_function()
202 (anonymous namespace)::b_function()
204 ** GDB now has much improved linespec and explicit locations TAB
205 completion support, that better understands what you're
206 completing and offers better suggestions. For example, GDB no
207 longer offers data symbols as possible completions when you're
208 setting a breakpoint.
210 ** GDB now TAB-completes label symbol names.
212 ** The "complete" command now mimics TAB completion accurately.
214 * New command line options (gcore)
217 Dump all memory mappings.
219 * Breakpoints on C++ functions are now set on all scopes by default
221 By default, breakpoints on functions/methods are now interpreted as
222 specifying all functions with the given name ignoring missing
223 leading scopes (namespaces and classes).
225 For example, assuming a C++ program with symbols named:
230 both commands "break func()" and "break B::func()" set a breakpoint
233 You can use the new flag "-qualified" to override this. This makes
234 GDB interpret the specified function name as a complete
235 fully-qualified name instead. For example, using the same C++
236 program, the "break -q B::func" command sets a breakpoint on
237 "B::func", only. A parameter has been added to the Python
238 gdb.Breakpoint constructor to achieve the same result when creating
239 a breakpoint from Python.
241 * Breakpoints on functions marked with C++ ABI tags
243 GDB can now set breakpoints on functions marked with C++ ABI tags
244 (e.g., [abi:cxx11]). See here for a description of ABI tags:
245 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
247 Functions with a C++11 abi tag are demangled/displayed like this:
249 function[abi:cxx11](int)
252 You can now set a breakpoint on such functions simply as if they had
255 (gdb) b function(int)
257 Or if you need to disambiguate between tags, like:
259 (gdb) b function[abi:other_tag](int)
261 Tab completion was adjusted accordingly as well.
265 ** New events gdb.new_inferior, gdb.inferior_deleted, and
266 gdb.new_thread are emitted. See the manual for further
267 description of these.
269 ** A new function, "gdb.rbreak" has been added to the Python API.
270 This function allows the setting of a large number of breakpoints
271 via a regex pattern in Python. See the manual for further details.
273 ** Python breakpoints can now accept explicit locations. See the
274 manual for a further description of this feature.
277 * New features in the GDB remote stub, GDBserver
279 ** GDBserver is now able to start inferior processes with a
280 specified initial working directory.
282 The user can set the desired working directory to be used from
283 GDB using the new "set cwd" command.
285 ** New "--selftest" command line option runs some GDBserver self
286 tests. These self tests are disabled in releases.
288 ** On Unix systems, GDBserver now does globbing expansion and variable
289 substitution in inferior command line arguments.
291 This is done by starting inferiors using a shell, like GDB does.
292 See "set startup-with-shell" in the user manual for how to disable
293 this from GDB when using "target extended-remote". When using
294 "target remote", you can disable the startup with shell by using the
295 new "--no-startup-with-shell" GDBserver command line option.
297 ** On Unix systems, GDBserver now supports receiving environment
298 variables that are to be set or unset from GDB. These variables
299 will affect the environment to be passed to the inferior.
301 * When catching an Ada exception raised with a message, GDB now prints
302 the message in the catchpoint hit notification. In GDB/MI mode, that
303 information is provided as an extra field named "exception-message"
304 in the *stopped notification.
306 * Trait objects can now be inspected When debugging Rust code. This
307 requires compiler support which will appear in Rust 1.24.
311 QEnvironmentHexEncoded
312 Inform GDBserver of an environment variable that is to be passed to
313 the inferior when starting it.
316 Inform GDBserver of an environment variable that is to be unset
317 before starting the remote inferior.
320 Inform GDBserver that the environment should be reset (i.e.,
321 user-set environment variables should be unset).
324 Indicates whether the inferior must be started with a shell or not.
327 Tell GDBserver that the inferior to be started should use a specific
330 * The "maintenance print c-tdesc" command now takes an optional
331 argument which is the file name of XML target description.
333 * The "maintenance selftest" command now takes an optional argument to
334 filter the tests to be run.
336 * The "enable", and "disable" commands now accept a range of
337 breakpoint locations, e.g. "enable 1.3-5".
342 Set and show the current working directory for the inferior.
345 Set and show compilation command used for compiling and injecting code
346 with the 'compile' commands.
348 set debug separate-debug-file
349 show debug separate-debug-file
350 Control the display of debug output about separate debug file search.
352 set dump-excluded-mappings
353 show dump-excluded-mappings
354 Control whether mappings marked with the VM_DONTDUMP flag should be
355 dumped when generating a core file.
358 List the registered selftests.
361 Start the debugged program stopping at the first instruction.
364 Control display of debugging messages related to OpenRISC targets.
366 set|show print type nested-type-limit
367 Set and show the limit of nesting level for nested types that the
368 type printer will show.
370 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
373 * Safer/improved support for debugging with no debug info
375 GDB no longer assumes functions with no debug information return
378 This means that GDB now refuses to call such functions unless you
379 tell it the function's type, by either casting the call to the
380 declared return type, or by casting the function to a function
381 pointer of the right type, and calling that:
383 (gdb) p getenv ("PATH")
384 'getenv' has unknown return type; cast the call to its declared return type
385 (gdb) p (char *) getenv ("PATH")
386 $1 = 0x7fffffffe "/usr/local/bin:/"...
387 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
388 $2 = 0x7fffffffe "/usr/local/bin:/"...
390 Similarly, GDB no longer assumes that global variables with no debug
391 info have type 'int', and refuses to print the variable's value
392 unless you tell it the variable's type:
395 'var' has unknown type; cast it to its declared type
399 * New native configurations
401 FreeBSD/aarch64 aarch64*-*-freebsd*
402 FreeBSD/arm arm*-*-freebsd*
406 FreeBSD/aarch64 aarch64*-*-freebsd*
407 FreeBSD/arm arm*-*-freebsd*
408 OpenRISC ELF or1k*-*-elf
410 * Removed targets and native configurations
412 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
414 *** Changes in GDB 8.0
416 * GDB now supports access to the PKU register on GNU/Linux. The register is
417 added by the Memory Protection Keys for Userspace feature which will be
418 available in future Intel CPUs.
420 * GDB now supports C++11 rvalue references.
424 ** New functions to start, stop and access a running btrace recording.
425 ** Rvalue references are now supported in gdb.Type.
427 * GDB now supports recording and replaying rdrand and rdseed Intel 64
430 * Building GDB and GDBserver now requires a C++11 compiler.
432 For example, GCC 4.8 or later.
434 It is no longer possible to build GDB or GDBserver with a C
435 compiler. The --disable-build-with-cxx configure option has been
438 * Building GDB and GDBserver now requires GNU make >= 3.81.
440 It is no longer supported to build GDB or GDBserver with another
441 implementation of the make program or an earlier version of GNU make.
443 * Native debugging on MS-Windows supports command-line redirection
445 Command-line arguments used for starting programs on MS-Windows can
446 now include redirection symbols supported by native Windows shells,
447 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
448 as "run", "start", and "set args", as well as the corresponding MI
451 * Support for thread names on MS-Windows.
453 GDB now catches and handles the special exception that programs
454 running on MS-Windows use to assign names to threads in the
457 * Support for Java programs compiled with gcj has been removed.
459 * User commands now accept an unlimited number of arguments.
460 Previously, only up to 10 was accepted.
462 * The "eval" command now expands user-defined command arguments.
464 This makes it easier to process a variable number of arguments:
469 eval "print $arg%d", $i
474 * Target descriptions can now describe registers for sparc32 and sparc64.
476 * GDB now supports DWARF version 5 (debug information format).
477 Its .debug_names index is not yet supported.
479 * New native configurations
481 FreeBSD/mips mips*-*-freebsd
485 Synopsys ARC arc*-*-elf32
486 FreeBSD/mips mips*-*-freebsd
488 * Removed targets and native configurations
490 Alpha running FreeBSD alpha*-*-freebsd*
491 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
496 Erases all the flash memory regions reported by the target.
498 maint print arc arc-instruction address
499 Print internal disassembler information about instruction at a given address.
503 set disassembler-options
504 show disassembler-options
505 Controls the passing of target specific information to the disassembler.
506 If it is necessary to specify more than one disassembler option then
507 multiple options can be placed together into a comma separated list.
508 The default value is the empty string. Currently, the only supported
509 targets are ARM, PowerPC and S/390.
514 Erases all the flash memory regions reported by the target. This is
515 equivalent to the CLI command flash-erase.
517 -file-list-shared-libraries
518 List the shared libraries in the program. This is
519 equivalent to the CLI command "info shared".
522 Catchpoints stopping the program when Ada exceptions are
523 handled. This is equivalent to the CLI command "catch handlers".
525 *** Changes in GDB 7.12
527 * GDB and GDBserver now build with a C++ compiler by default.
529 The --enable-build-with-cxx configure option is now enabled by
530 default. One must now explicitly configure with
531 --disable-build-with-cxx in order to build with a C compiler. This
532 option will be removed in a future release.
534 * GDBserver now supports recording btrace without maintaining an active
537 * GDB now supports a negative repeat count in the 'x' command to examine
538 memory backward from the given address. For example:
541 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
542 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
543 (gdb) x/-5i 0x0000000000400580
544 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
545 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
546 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
547 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
548 0x40057b <main(int, char**)+25>:
549 callq 0x400536 <Func1(int, char const*)>
551 * Fortran: Support structures with fields of dynamic types and
552 arrays of dynamic types.
554 * The symbol dumping maintenance commands have new syntax.
555 maint print symbols [-pc address] [--] [filename]
556 maint print symbols [-objfile objfile] [-source source] [--] [filename]
557 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
558 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
559 maint print msymbols [-objfile objfile] [--] [filename]
561 * GDB now supports multibit bitfields and enums in target register
564 * New Python-based convenience function $_as_string(val), which returns
565 the textual representation of a value. This function is especially
566 useful to obtain the text label of an enum value.
568 * Intel MPX bound violation handling.
570 Segmentation faults caused by a Intel MPX boundary violation
571 now display the kind of violation (upper or lower), the memory
572 address accessed and the memory bounds, along with the usual
573 signal received and code location.
577 Program received signal SIGSEGV, Segmentation fault
578 Upper bound violation while accessing address 0x7fffffffc3b3
579 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
580 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
582 * Rust language support.
583 GDB now supports debugging programs written in the Rust programming
584 language. See https://www.rust-lang.org/ for more information about
587 * Support for running interpreters on specified input/output devices
589 GDB now supports a new mechanism that allows frontends to provide
590 fully featured GDB console views, as a better alternative to
591 building such views on top of the "-interpreter-exec console"
592 command. See the new "new-ui" command below. With that command,
593 frontends can now start GDB in the traditional command-line mode
594 running in an embedded terminal emulator widget, and create a
595 separate MI interpreter running on a specified i/o device. In this
596 way, GDB handles line editing, history, tab completion, etc. in the
597 console all by itself, and the GUI uses the separate MI interpreter
598 for its own control and synchronization, invisible to the command
601 * The "catch syscall" command catches groups of related syscalls.
603 The "catch syscall" command now supports catching a group of related
604 syscalls using the 'group:' or 'g:' prefix.
609 skip -gfile file-glob-pattern
610 skip -function function
611 skip -rfunction regular-expression
612 A generalized form of the skip command, with new support for
613 glob-style file names and regular expressions for function names.
614 Additionally, a file spec and a function spec may now be combined.
616 maint info line-table REGEXP
617 Display the contents of GDB's internal line table data struture.
620 Run any GDB unit tests that were compiled in.
623 Start a new user interface instance running INTERP as interpreter,
624 using the TTY file for input/output.
628 ** gdb.Breakpoint objects have a new attribute "pending", which
629 indicates whether the breakpoint is pending.
630 ** Three new breakpoint-related events have been added:
631 gdb.breakpoint_created, gdb.breakpoint_modified, and
632 gdb.breakpoint_deleted.
635 Signal ("set") the given MS-Windows event object. This is used in
636 conjunction with the Windows JIT debugging (AeDebug) support, where
637 the OS suspends a crashing process until a debugger can attach to
638 it. Resuming the crashing process, in order to debug it, is done by
641 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
642 was added in GDBserver, including JIT compiling fast tracepoint's
643 conditional expression bytecode into native code.
645 * Support for various remote target protocols and ROM monitors has
648 target m32rsdi Remote M32R debugging over SDI
649 target mips MIPS remote debugging protocol
650 target pmon PMON ROM monitor
651 target ddb NEC's DDB variant of PMON for Vr4300
652 target rockhopper NEC RockHopper variant of PMON
653 target lsi LSI variant of PMO
655 * Support for tracepoints and fast tracepoints on powerpc-linux,
656 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
657 including JIT compiling fast tracepoint's conditional expression
658 bytecode into native code.
660 * MI async record =record-started now includes the method and format used for
661 recording. For example:
663 =record-started,thread-group="i1",method="btrace",format="bts"
665 * MI async record =thread-selected now includes the frame field. For example:
667 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
671 Andes NDS32 nds32*-*-elf
673 *** Changes in GDB 7.11
675 * GDB now supports debugging kernel-based threads on FreeBSD.
677 * Per-inferior thread numbers
679 Thread numbers are now per inferior instead of global. If you're
680 debugging multiple inferiors, GDB displays thread IDs using a
681 qualified INF_NUM.THR_NUM form. For example:
685 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
686 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
687 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
688 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
690 As consequence, thread numbers as visible in the $_thread
691 convenience variable and in Python's InferiorThread.num attribute
692 are no longer unique between inferiors.
694 GDB now maintains a second thread ID per thread, referred to as the
695 global thread ID, which is the new equivalent of thread numbers in
696 previous releases. See also $_gthread below.
698 For backwards compatibility, MI's thread IDs always refer to global
701 * Commands that accept thread IDs now accept the qualified
702 INF_NUM.THR_NUM form as well. For example:
705 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
708 * In commands that accept a list of thread IDs, you can now refer to
709 all threads of an inferior using a star wildcard. GDB accepts
710 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
711 refer to all threads of the current inferior. For example, "info
714 * You can use "info threads -gid" to display the global thread ID of
717 * The new convenience variable $_gthread holds the global number of
720 * The new convenience variable $_inferior holds the number of the
723 * GDB now displays the ID and name of the thread that hit a breakpoint
724 or received a signal, if your program is multi-threaded. For
727 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
728 Thread 1 "main" received signal SIGINT, Interrupt.
730 * Record btrace now supports non-stop mode.
732 * Support for tracepoints on aarch64-linux was added in GDBserver.
734 * The 'record instruction-history' command now indicates speculative execution
735 when using the Intel Processor Trace recording format.
737 * GDB now allows users to specify explicit locations, bypassing
738 the linespec parser. This feature is also available to GDB/MI
741 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
742 GDB now is able to debug both AArch64 applications and ARM applications
745 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
746 including JIT compiling fast tracepoint's conditional expression bytecode
749 * GDB now supports displaced stepping on AArch64 GNU/Linux.
751 * "info threads", "info inferiors", "info display", "info checkpoints"
752 and "maint info program-spaces" now list the corresponding items in
753 ascending ID order, for consistency with all other "info" commands.
755 * In Ada, the overloads selection menu has been enhanced to display the
756 parameter types and the return types for the matching overloaded subprograms.
760 maint set target-non-stop (on|off|auto)
761 maint show target-non-stop
762 Control whether GDB targets always operate in non-stop mode even if
763 "set non-stop" is "off". The default is "auto", meaning non-stop
764 mode is enabled if supported by the target.
766 maint set bfd-sharing
767 maint show bfd-sharing
768 Control the reuse of bfd objects.
772 Control display of debugging info regarding bfd caching.
776 Control display of debugging info regarding FreeBSD threads.
778 set remote multiprocess-extensions-packet
779 show remote multiprocess-extensions-packet
780 Set/show the use of the remote protocol multiprocess extensions.
782 set remote thread-events
783 show remote thread-events
784 Set/show the use of thread create/exit events.
786 set ada print-signatures on|off
787 show ada print-signatures"
788 Control whether parameter types and return types are displayed in overloads
789 selection menus. It is activaled (@code{on}) by default.
793 Controls the maximum size of memory, in bytes, that GDB will
794 allocate for value contents. Prevents incorrect programs from
795 causing GDB to allocate overly large buffers. Default is 64k.
797 * The "disassemble" command accepts a new modifier: /s.
798 It prints mixed source+disassembly like /m with two differences:
799 - disassembled instructions are now printed in program order, and
800 - and source for all relevant files is now printed.
801 The "/m" option is now considered deprecated: its "source-centric"
802 output hasn't proved useful in practice.
804 * The "record instruction-history" command accepts a new modifier: /s.
805 It behaves exactly like /m and prints mixed source+disassembly.
807 * The "set scheduler-locking" command supports a new mode "replay".
808 It behaves like "off" in record mode and like "on" in replay mode.
810 * Support for various ROM monitors has been removed:
812 target dbug dBUG ROM monitor for Motorola ColdFire
813 target picobug Motorola picobug monitor
814 target dink32 DINK32 ROM monitor for PowerPC
815 target m32r Renesas M32R/D ROM monitor
816 target mon2000 mon2000 ROM monitor
817 target ppcbug PPCBUG ROM monitor for PowerPC
819 * Support for reading/writing memory and extracting values on architectures
820 whose memory is addressable in units of any integral multiple of 8 bits.
823 Allows to break when an Ada exception is handled.
828 Indicates that an exec system call was executed.
830 exec-events feature in qSupported
831 The qSupported packet allows GDB to request support for exec
832 events using the new 'gdbfeature' exec-event, and the qSupported
833 response can contain the corresponding 'stubfeature'. Set and
834 show commands can be used to display whether these features are enabled.
837 Equivalent to interrupting with the ^C character, but works in
840 thread created stop reason (T05 create:...)
841 Indicates that the thread was just created and is stopped at entry.
843 thread exit stop reply (w exitcode;tid)
844 Indicates that the thread has terminated.
847 Enables/disables thread create and exit event reporting. For
848 example, this is used in non-stop mode when GDB stops a set of
849 threads and synchronously waits for the their corresponding stop
850 replies. Without exit events, if one of the threads exits, GDB
851 would hang forever not knowing that it should no longer expect a
852 stop for that same thread.
855 Indicates that there are no resumed threads left in the target (all
856 threads are stopped). The remote stub reports support for this stop
857 reply to GDB's qSupported query.
860 Enables/disables catching syscalls from the inferior process.
861 The remote stub reports support for this packet to GDB's qSupported query.
863 syscall_entry stop reason
864 Indicates that a syscall was just called.
866 syscall_return stop reason
867 Indicates that a syscall just returned.
869 * Extended-remote exec events
871 ** GDB now has support for exec events on extended-remote Linux targets.
872 For such targets with Linux kernels 2.5.46 and later, this enables
873 follow-exec-mode and exec catchpoints.
875 set remote exec-event-feature-packet
876 show remote exec-event-feature-packet
877 Set/show the use of the remote exec event feature.
879 * Thread names in remote protocol
881 The reply to qXfer:threads:read may now include a name attribute for each
884 * Target remote mode fork and exec events
886 ** GDB now has support for fork and exec events on target remote mode
887 Linux targets. For such targets with Linux kernels 2.5.46 and later,
888 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
889 fork and exec catchpoints.
891 * Remote syscall events
893 ** GDB now has support for catch syscall on remote Linux targets,
894 currently enabled on x86/x86_64 architectures.
896 set remote catch-syscall-packet
897 show remote catch-syscall-packet
898 Set/show the use of the remote catch syscall feature.
902 ** The -var-set-format command now accepts the zero-hexadecimal
903 format. It outputs data in hexadecimal format with zero-padding on the
908 ** gdb.InferiorThread objects have a new attribute "global_num",
909 which refers to the thread's global thread ID. The existing
910 "num" attribute now refers to the thread's per-inferior number.
911 See "Per-inferior thread numbers" above.
912 ** gdb.InferiorThread objects have a new attribute "inferior", which
913 is the Inferior object the thread belongs to.
915 *** Changes in GDB 7.10
917 * Support for process record-replay and reverse debugging on aarch64*-linux*
918 targets has been added. GDB now supports recording of A64 instruction set
919 including advance SIMD instructions.
921 * Support for Sun's version of the "stabs" debug file format has been removed.
923 * GDB now honors the content of the file /proc/PID/coredump_filter
924 (PID is the process ID) on GNU/Linux systems. This file can be used
925 to specify the types of memory mappings that will be included in a
926 corefile. For more information, please refer to the manual page of
927 "core(5)". GDB also has a new command: "set use-coredump-filter
928 on|off". It allows to set whether GDB will read the content of the
929 /proc/PID/coredump_filter file when generating a corefile.
931 * The "info os" command on GNU/Linux can now display information on
933 "info os cpus" Listing of all cpus/cores on the system
935 * GDB has two new commands: "set serial parity odd|even|none" and
936 "show serial parity". These allows to set or show parity for the
939 * The "info source" command now displays the producer string if it was
940 present in the debug info. This typically includes the compiler version
941 and may include things like its command line arguments.
943 * The "info dll", an alias of the "info sharedlibrary" command,
944 is now available on all platforms.
946 * Directory names supplied to the "set sysroot" commands may be
947 prefixed with "target:" to tell GDB to access shared libraries from
948 the target system, be it local or remote. This replaces the prefix
949 "remote:". The default sysroot has been changed from "" to
950 "target:". "remote:" is automatically converted to "target:" for
951 backward compatibility.
953 * The system root specified by "set sysroot" will be prepended to the
954 filename of the main executable (if reported to GDB as absolute by
955 the operating system) when starting processes remotely, and when
956 attaching to already-running local or remote processes.
958 * GDB now supports automatic location and retrieval of executable
959 files from remote targets. Remote debugging can now be initiated
960 using only a "target remote" or "target extended-remote" command
961 (no "set sysroot" or "file" commands are required). See "New remote
964 * The "dump" command now supports verilog hex format.
966 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
968 * On GNU/Linux, GDB and gdbserver are now able to access executable
969 and shared library files without a "set sysroot" command when
970 attaching to processes running in different mount namespaces from
971 the debugger. This makes it possible to attach to processes in
972 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
973 See "New remote packets" below.
975 * The "tui reg" command now provides completion for all of the
976 available register groups, including target specific groups.
978 * The HISTSIZE environment variable is no longer read when determining
979 the size of GDB's command history. GDB now instead reads the dedicated
980 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
981 disables truncation of command history. Non-numeric values of GDBHISTSIZE
986 ** Memory ports can now be unbuffered.
990 ** gdb.Objfile objects have a new attribute "username",
991 which is the name of the objfile as specified by the user,
992 without, for example, resolving symlinks.
993 ** You can now write frame unwinders in Python.
994 ** gdb.Type objects have a new method "optimized_out",
995 returning optimized out gdb.Value instance of this type.
996 ** gdb.Value objects have new methods "reference_value" and
997 "const_value" which return a reference to the value and a
998 "const" version of the value respectively.
1002 maint print symbol-cache
1003 Print the contents of the symbol cache.
1005 maint print symbol-cache-statistics
1006 Print statistics of symbol cache usage.
1008 maint flush-symbol-cache
1009 Flush the contents of the symbol cache.
1013 Start branch trace recording using Branch Trace Store (BTS) format.
1016 Evaluate expression by using the compiler and print result.
1020 Explicit commands for enabling and disabling tui mode.
1023 set mpx bound on i386 and amd64
1024 Support for bound table investigation on Intel MPX enabled applications.
1028 Start branch trace recording using Intel Processor Trace format.
1031 Print information about branch tracing internals.
1033 maint btrace packet-history
1034 Print the raw branch tracing data.
1036 maint btrace clear-packet-history
1037 Discard the stored raw branch tracing data.
1040 Discard all branch tracing data. It will be fetched and processed
1041 anew by the next "record" command.
1046 Renamed from "set debug dwarf2-die".
1047 show debug dwarf-die
1048 Renamed from "show debug dwarf2-die".
1050 set debug dwarf-read
1051 Renamed from "set debug dwarf2-read".
1052 show debug dwarf-read
1053 Renamed from "show debug dwarf2-read".
1055 maint set dwarf always-disassemble
1056 Renamed from "maint set dwarf2 always-disassemble".
1057 maint show dwarf always-disassemble
1058 Renamed from "maint show dwarf2 always-disassemble".
1060 maint set dwarf max-cache-age
1061 Renamed from "maint set dwarf2 max-cache-age".
1062 maint show dwarf max-cache-age
1063 Renamed from "maint show dwarf2 max-cache-age".
1065 set debug dwarf-line
1066 show debug dwarf-line
1067 Control display of debugging info regarding DWARF line processing.
1070 show max-completions
1071 Set the maximum number of candidates to be considered during
1072 completion. The default value is 200. This limit allows GDB
1073 to avoid generating large completion lists, the computation of
1074 which can cause the debugger to become temporarily unresponsive.
1076 set history remove-duplicates
1077 show history remove-duplicates
1078 Control the removal of duplicate history entries.
1080 maint set symbol-cache-size
1081 maint show symbol-cache-size
1082 Control the size of the symbol cache.
1084 set|show record btrace bts buffer-size
1085 Set and show the size of the ring buffer used for branch tracing in
1087 The obtained size may differ from the requested size. Use "info
1088 record" to see the obtained buffer size.
1090 set debug linux-namespaces
1091 show debug linux-namespaces
1092 Control display of debugging info regarding Linux namespaces.
1094 set|show record btrace pt buffer-size
1095 Set and show the size of the ring buffer used for branch tracing in
1096 Intel Processor Trace format.
1097 The obtained size may differ from the requested size. Use "info
1098 record" to see the obtained buffer size.
1100 maint set|show btrace pt skip-pad
1101 Set and show whether PAD packets are skipped when computing the
1104 * The command 'thread apply all' can now support new option '-ascending'
1105 to call its specified command for all threads in ascending order.
1107 * Python/Guile scripting
1109 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1110 special section named `.debug_gdb_scripts'.
1112 * New remote packets
1114 qXfer:btrace-conf:read
1115 Return the branch trace configuration for the current thread.
1117 Qbtrace-conf:bts:size
1118 Set the requested ring buffer size for branch tracing in BTS format.
1121 Enable Intel Procesor Trace-based branch tracing for the current
1122 process. The remote stub reports support for this packet to GDB's
1125 Qbtrace-conf:pt:size
1126 Set the requested ring buffer size for branch tracing in Intel Processor
1130 Indicates a memory breakpoint instruction was executed, irrespective
1131 of whether it was GDB that planted the breakpoint or the breakpoint
1132 is hardcoded in the program. This is required for correct non-stop
1136 Indicates the target stopped for a hardware breakpoint. This is
1137 required for correct non-stop mode operation.
1140 Return information about files on the remote system.
1142 qXfer:exec-file:read
1143 Return the full absolute name of the file that was executed to
1144 create a process running on the remote system.
1147 Select the filesystem on which vFile: operations with filename
1148 arguments will operate. This is required for GDB to be able to
1149 access files on remote targets where the remote stub does not
1150 share a common filesystem with the inferior(s).
1153 Indicates that a fork system call was executed.
1156 Indicates that a vfork system call was executed.
1158 vforkdone stop reason
1159 Indicates that a vfork child of the specified process has executed
1160 an exec or exit, allowing the vfork parent to resume execution.
1162 fork-events and vfork-events features in qSupported
1163 The qSupported packet allows GDB to request support for fork and
1164 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1165 and the qSupported response can contain the corresponding
1166 'stubfeatures'. Set and show commands can be used to display
1167 whether these features are enabled.
1169 * Extended-remote fork events
1171 ** GDB now has support for fork events on extended-remote Linux
1172 targets. For targets with Linux kernels 2.5.60 and later, this
1173 enables follow-fork-mode and detach-on-fork for both fork and
1174 vfork, as well as fork and vfork catchpoints.
1176 * The info record command now shows the recording format and the
1177 branch tracing configuration for the current thread when using
1178 the btrace record target.
1179 For the BTS format, it shows the ring buffer size.
1181 * GDB now has support for DTrace USDT (Userland Static Defined
1182 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1184 * GDB now supports access to vector registers on S/390 GNU/Linux
1187 * Removed command line options
1189 -xdb HP-UX XDB compatibility mode.
1191 * Removed targets and native configurations
1193 HP/PA running HP-UX hppa*-*-hpux*
1194 Itanium running HP-UX ia64-*-hpux*
1196 * New configure options
1199 This configure option allows the user to build GDB with support for
1200 Intel Processor Trace (default: auto). This requires libipt.
1202 --with-libipt-prefix=PATH
1203 Specify the path to the version of libipt that GDB should use.
1204 $PATH/include should contain the intel-pt.h header and
1205 $PATH/lib should contain the libipt.so library.
1207 *** Changes in GDB 7.9.1
1211 ** Xmethods can now specify a result type.
1213 *** Changes in GDB 7.9
1215 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1219 ** You can now access frame registers from Python scripts.
1220 ** New attribute 'producer' for gdb.Symtab objects.
1221 ** gdb.Objfile objects have a new attribute "progspace",
1222 which is the gdb.Progspace object of the containing program space.
1223 ** gdb.Objfile objects have a new attribute "owner".
1224 ** gdb.Objfile objects have a new attribute "build_id",
1225 which is the build ID generated when the file was built.
1226 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1227 ** A new event "gdb.clear_objfiles" has been added, triggered when
1228 selecting a new file to debug.
1229 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1230 ** New function gdb.lookup_objfile.
1232 New events which are triggered when GDB modifies the state of the
1235 ** gdb.events.inferior_call_pre: Function call is about to be made.
1236 ** gdb.events.inferior_call_post: Function call has just been made.
1237 ** gdb.events.memory_changed: A memory location has been altered.
1238 ** gdb.events.register_changed: A register has been altered.
1240 * New Python-based convenience functions:
1242 ** $_caller_is(name [, number_of_frames])
1243 ** $_caller_matches(regexp [, number_of_frames])
1244 ** $_any_caller_is(name [, number_of_frames])
1245 ** $_any_caller_matches(regexp [, number_of_frames])
1247 * GDB now supports the compilation and injection of source code into
1248 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1249 to compile the source code to object code, and if successful, inject
1250 and execute that code within the current context of the inferior.
1251 Currently the C language is supported. The commands used to
1252 interface with this new feature are:
1254 compile code [-raw|-r] [--] [source code]
1255 compile file [-raw|-r] filename
1259 demangle [-l language] [--] name
1260 Demangle "name" in the specified language, or the current language
1261 if elided. This command is renamed from the "maint demangle" command.
1262 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1263 as "maint demangler-warning".
1265 queue-signal signal-name-or-number
1266 Queue a signal to be delivered to the thread when it is resumed.
1268 add-auto-load-scripts-directory directory
1269 Add entries to the list of directories from which to load auto-loaded
1272 maint print user-registers
1273 List all currently available "user" registers.
1275 compile code [-r|-raw] [--] [source code]
1276 Compile, inject, and execute in the inferior the executable object
1277 code produced by compiling the provided source code.
1279 compile file [-r|-raw] filename
1280 Compile and inject into the inferior the executable object code
1281 produced by compiling the source code stored in the filename
1284 * On resume, GDB now always passes the signal the program had stopped
1285 for to the thread the signal was sent to, even if the user changed
1286 threads before resuming. Previously GDB would often (but not
1287 always) deliver the signal to the thread that happens to be current
1290 * Conversely, the "signal" command now consistently delivers the
1291 requested signal to the current thread. GDB now asks for
1292 confirmation if the program had stopped for a signal and the user
1293 switched threads meanwhile.
1295 * "breakpoint always-inserted" modes "off" and "auto" merged.
1297 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1298 won't remove breakpoints from the target until all threads stop,
1299 even in non-stop mode. The "auto" mode has been removed, and "off"
1300 is now the default mode.
1304 set debug symbol-lookup
1305 show debug symbol-lookup
1306 Control display of debugging info regarding symbol lookup.
1310 ** The -list-thread-groups command outputs an exit-code field for
1311 inferiors that have exited.
1315 MIPS SDE mips*-sde*-elf*
1319 Support for these obsolete configurations has been removed.
1321 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1322 SGI Irix-5.x mips-*-irix5*
1323 SGI Irix-6.x mips-*-irix6*
1324 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1325 VAX running Ultrix vax-*-ultrix*
1327 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1328 and "assf"), have been removed. Use the "sharedlibrary" command, or
1329 its alias "share", instead.
1331 *** Changes in GDB 7.8
1333 * New command line options
1336 This is an alias for the --data-directory option.
1338 * GDB supports printing and modifying of variable length automatic arrays
1339 as specified in ISO C99.
1341 * The ARM simulator now supports instruction level tracing
1342 with or without disassembly.
1346 GDB now has support for scripting using Guile. Whether this is
1347 available is determined at configure time.
1348 Guile version 2.0 or greater is required.
1349 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1351 * New commands (for set/show, see "New options" below)
1355 Invoke CODE by passing it to the Guile interpreter.
1359 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1361 info auto-load guile-scripts [regexp]
1362 Print the list of automatically loaded Guile scripts.
1364 * The source command is now capable of sourcing Guile scripts.
1365 This feature is dependent on the debugger being built with Guile support.
1369 set print symbol-loading (off|brief|full)
1370 show print symbol-loading
1371 Control whether to print informational messages when loading symbol
1372 information for a file. The default is "full", but when debugging
1373 programs with large numbers of shared libraries the amount of output
1374 becomes less useful.
1376 set guile print-stack (none|message|full)
1377 show guile print-stack
1378 Show a stack trace when an error is encountered in a Guile script.
1380 set auto-load guile-scripts (on|off)
1381 show auto-load guile-scripts
1382 Control auto-loading of Guile script files.
1384 maint ada set ignore-descriptive-types (on|off)
1385 maint ada show ignore-descriptive-types
1386 Control whether the debugger should ignore descriptive types in Ada
1387 programs. The default is not to ignore the descriptive types. See
1388 the user manual for more details on descriptive types and the intended
1389 usage of this option.
1391 set auto-connect-native-target
1393 Control whether GDB is allowed to automatically connect to the
1394 native target for the run, attach, etc. commands when not connected
1395 to any target yet. See also "target native" below.
1397 set record btrace replay-memory-access (read-only|read-write)
1398 show record btrace replay-memory-access
1399 Control what memory accesses are allowed during replay.
1401 maint set target-async (on|off)
1402 maint show target-async
1403 This controls whether GDB targets operate in synchronous or
1404 asynchronous mode. Normally the default is asynchronous, if it is
1405 available; but this can be changed to more easily debug problems
1406 occurring only in synchronous mode.
1408 set mi-async (on|off)
1410 Control whether MI asynchronous mode is preferred. This supersedes
1411 "set target-async" of previous GDB versions.
1413 * "set target-async" is deprecated as a CLI option and is now an alias
1414 for "set mi-async" (only puts MI into async mode).
1416 * Background execution commands (e.g., "c&", "s&", etc.) are now
1417 possible ``out of the box'' if the target supports them. Previously
1418 the user would need to explicitly enable the possibility with the
1419 "set target-async on" command.
1421 * New features in the GDB remote stub, GDBserver
1423 ** New option --debug-format=option1[,option2,...] allows one to add
1424 additional text to each output. At present only timestamps
1425 are supported: --debug-format=timestamps.
1426 Timestamps can also be turned on with the
1427 "monitor set debug-format timestamps" command from GDB.
1429 * The 'record instruction-history' command now starts counting instructions
1430 at one. This also affects the instruction ranges reported by the
1431 'record function-call-history' command when given the /i modifier.
1433 * The command 'record function-call-history' supports a new modifier '/c' to
1434 indent the function names based on their call stack depth.
1435 The fields for the '/i' and '/l' modifier have been reordered.
1436 The source line range is now prefixed with 'at'.
1437 The instruction range is now prefixed with 'inst'.
1438 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1439 "record instruction-history" and "list" commands.
1441 * The ranges given as arguments to the 'record function-call-history' and
1442 'record instruction-history' commands are now inclusive.
1444 * The btrace record target now supports the 'record goto' command.
1445 For locations inside the execution trace, the back trace is computed
1446 based on the information stored in the execution trace.
1448 * The btrace record target supports limited reverse execution and replay.
1449 The target does not record data and therefore does not allow reading
1450 memory or registers.
1452 * The "catch syscall" command now works on s390*-linux* targets.
1454 * The "compare-sections" command is no longer specific to target
1455 remote. It now works with all targets.
1457 * All native targets are now consistently called "native".
1458 Consequently, the "target child", "target GNU", "target djgpp",
1459 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1460 commands have been replaced with "target native". The QNX/NTO port
1461 leaves the "procfs" target in place and adds a "native" target for
1462 consistency with other ports. The impact on users should be minimal
1463 as these commands previously either throwed an error, or were
1464 no-ops. The target's name is visible in the output of the following
1465 commands: "help target", "info target", "info files", "maint print
1468 * The "target native" command now connects to the native target. This
1469 can be used to launch native programs even when "set
1470 auto-connect-native-target" is set to off.
1472 * GDB now supports access to Intel MPX registers on GNU/Linux.
1474 * Support for Intel AVX-512 registers on GNU/Linux.
1475 Support displaying and modifying Intel AVX-512 registers
1476 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1478 * New remote packets
1480 qXfer:btrace:read's annex
1481 The qXfer:btrace:read packet supports a new annex 'delta' to read
1482 branch trace incrementally.
1486 ** Valid Python operations on gdb.Value objects representing
1487 structs/classes invoke the corresponding overloaded operators if
1489 ** New `Xmethods' feature in the Python API. Xmethods are
1490 additional methods or replacements for existing methods of a C++
1491 class. This feature is useful for those cases where a method
1492 defined in C++ source code could be inlined or optimized out by
1493 the compiler, making it unavailable to GDB.
1496 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1498 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1499 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1500 its alias "share", instead.
1502 * The commands "set remotebaud" and "show remotebaud" are no longer
1503 supported. Use "set serial baud" and "show serial baud" (respectively)
1508 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1509 target-async". The latter is left as a deprecated alias of the
1510 former for backward compatibility. If the target supports it,
1511 CLI background execution commands are now always possible by
1512 default, independently of whether the frontend stated a
1513 preference for asynchronous execution with "-gdb-set mi-async".
1514 Previously "-gdb-set target-async off" affected both MI execution
1515 commands and CLI execution commands.
1517 *** Changes in GDB 7.7
1519 * Improved support for process record-replay and reverse debugging on
1520 arm*-linux* targets. Support for thumb32 and syscall instruction
1521 recording has been added.
1523 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1525 * GDB now supports Fission DWP file format version 2.
1526 http://gcc.gnu.org/wiki/DebugFission
1528 * New convenience function "$_isvoid", to check whether an expression
1529 is void. A void expression is an expression where the type of the
1530 result is "void". For example, some convenience variables may be
1531 "void" when evaluated (e.g., "$_exitcode" before the execution of
1532 the program being debugged; or an undefined convenience variable).
1533 Another example, when calling a function whose return type is
1536 * The "maintenance print objfiles" command now takes an optional regexp.
1538 * The "catch syscall" command now works on arm*-linux* targets.
1540 * GDB now consistently shows "<not saved>" when printing values of
1541 registers the debug info indicates have not been saved in the frame
1542 and there's nowhere to retrieve them from
1543 (callee-saved/call-clobbered registers):
1548 (gdb) info registers rax
1551 Before, the former would print "<optimized out>", and the latter
1552 "*value not available*".
1554 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1559 ** Frame filters and frame decorators have been added.
1560 ** Temporary breakpoints are now supported.
1561 ** Line tables representation has been added.
1562 ** New attribute 'parent_type' for gdb.Field objects.
1563 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1564 ** New attribute 'name' for gdb.Type objects.
1568 Nios II ELF nios2*-*-elf
1569 Nios II GNU/Linux nios2*-*-linux
1570 Texas Instruments MSP430 msp430*-*-elf
1572 * Removed native configurations
1574 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1575 been removed. ELF variants of these configurations are kept supported.
1577 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1578 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1579 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1580 i[34567]86-*-openbsd3.[0-3]
1581 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1582 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1583 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1587 Like "catch throw", but catches a re-thrown exception.
1588 maint check-psymtabs
1589 Renamed from old "maint check-symtabs".
1591 Perform consistency checks on symtabs.
1592 maint expand-symtabs
1593 Expand symtabs matching an optional regexp.
1596 Display the details of GDB configure-time options.
1598 maint set|show per-command
1599 maint set|show per-command space
1600 maint set|show per-command time
1601 maint set|show per-command symtab
1602 Enable display of per-command gdb resource usage.
1604 remove-symbol-file FILENAME
1605 remove-symbol-file -a ADDRESS
1606 Remove a symbol file added via add-symbol-file. The file to remove
1607 can be identified by its filename or by an address that lies within
1608 the boundaries of this symbol file in memory.
1611 info exceptions REGEXP
1612 Display the list of Ada exceptions defined in the program being
1613 debugged. If provided, only the exceptions whose names match REGEXP
1618 set debug symfile off|on
1620 Control display of debugging info regarding reading symbol files and
1621 symbol tables within those files
1623 set print raw frame-arguments
1624 show print raw frame-arguments
1625 Set/show whether to print frame arguments in raw mode,
1626 disregarding any defined pretty-printers.
1628 set remote trace-status-packet
1629 show remote trace-status-packet
1630 Set/show the use of remote protocol qTStatus packet.
1634 Control display of debugging messages related to Nios II targets.
1638 Control whether target-assisted range stepping is enabled.
1640 set startup-with-shell
1641 show startup-with-shell
1642 Specifies whether Unix child processes are started via a shell or
1647 Use the target memory cache for accesses to the code segment. This
1648 improves performance of remote debugging (particularly disassembly).
1650 * You can now use a literal value 'unlimited' for options that
1651 interpret 0 or -1 as meaning "unlimited". E.g., "set
1652 trace-buffer-size unlimited" is now an alias for "set
1653 trace-buffer-size -1" and "set height unlimited" is now an alias for
1656 * The "set debug symtab-create" debugging option of GDB has been changed to
1657 accept a verbosity level. 0 means "off", 1 provides basic debugging
1658 output, and values of 2 or greater provides more verbose output.
1660 * New command-line options
1662 Display the details of GDB configure-time options.
1664 * The command 'tsave' can now support new option '-ctf' to save trace
1665 buffer in Common Trace Format.
1667 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1670 * GDB now implements the the C++ 'typeid' operator.
1672 * The new convenience variable $_exception holds the exception being
1673 thrown or caught at an exception-related catchpoint.
1675 * The exception-related catchpoints, like "catch throw", now accept a
1676 regular expression which can be used to filter exceptions by type.
1678 * The new convenience variable $_exitsignal is automatically set to
1679 the terminating signal number when the program being debugged dies
1680 due to an uncaught signal.
1684 ** All MI commands now accept an optional "--language" option.
1685 Support for this feature can be verified by using the "-list-features"
1686 command, which should contain "language-option".
1688 ** The new command -info-gdb-mi-command allows the user to determine
1689 whether a GDB/MI command is supported or not.
1691 ** The "^error" result record returned when trying to execute an undefined
1692 GDB/MI command now provides a variable named "code" whose content is the
1693 "undefined-command" error code. Support for this feature can be verified
1694 by using the "-list-features" command, which should contain
1695 "undefined-command-error-code".
1697 ** The -trace-save MI command can optionally save trace buffer in Common
1700 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1702 ** The command -data-list-register-values now accepts an optional
1703 "--skip-unavailable" option. When used, only the available registers
1706 ** The new command -trace-frame-collected dumps collected variables,
1707 computed expressions, tvars, memory and registers in a traceframe.
1709 ** The commands -stack-list-locals, -stack-list-arguments and
1710 -stack-list-variables now accept an option "--skip-unavailable".
1711 When used, only the available locals or arguments are displayed.
1713 ** The -exec-run command now accepts an optional "--start" option.
1714 When used, the command follows the same semantics as the "start"
1715 command, stopping the program's execution at the start of its
1716 main subprogram. Support for this feature can be verified using
1717 the "-list-features" command, which should contain
1718 "exec-run-start-option".
1720 ** The new commands -catch-assert and -catch-exceptions insert
1721 catchpoints stopping the program when Ada exceptions are raised.
1723 ** The new command -info-ada-exceptions provides the equivalent of
1724 the new "info exceptions" command.
1726 * New system-wide configuration scripts
1727 A GDB installation now provides scripts suitable for use as system-wide
1728 configuration scripts for the following systems:
1732 * GDB now supports target-assigned range stepping with remote targets.
1733 This improves the performance of stepping source lines by reducing
1734 the number of control packets from/to GDB. See "New remote packets"
1737 * GDB now understands the element 'tvar' in the XML traceframe info.
1738 It has the id of the collected trace state variables.
1740 * On S/390 targets that provide the transactional-execution feature,
1741 the program interruption transaction diagnostic block (TDB) is now
1742 represented as a number of additional "registers" in GDB.
1744 * New remote packets
1748 The vCont packet supports a new 'r' action, that tells the remote
1749 stub to step through an address range itself, without GDB
1750 involvemement at each single-step.
1752 qXfer:libraries-svr4:read's annex
1753 The previously unused annex of the qXfer:libraries-svr4:read packet
1754 is now used to support passing an argument list. The remote stub
1755 reports support for this argument list to GDB's qSupported query.
1756 The defined arguments are "start" and "prev", used to reduce work
1757 necessary for library list updating, resulting in significant
1760 * New features in the GDB remote stub, GDBserver
1762 ** GDBserver now supports target-assisted range stepping. Currently
1763 enabled on x86/x86_64 GNU/Linux targets.
1765 ** GDBserver now adds element 'tvar' in the XML in the reply to
1766 'qXfer:traceframe-info:read'. It has the id of the collected
1767 trace state variables.
1769 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1772 * New 'z' formatter for printing and examining memory, this displays the
1773 value as hexadecimal zero padded on the left to the size of the type.
1775 * GDB can now use Windows x64 unwinding data.
1777 * The "set remotebaud" command has been replaced by "set serial baud".
1778 Similarly, "show remotebaud" has been replaced by "show serial baud".
1779 The "set remotebaud" and "show remotebaud" commands are still available
1780 to provide backward compatibility with older versions of GDB.
1782 *** Changes in GDB 7.6
1784 * Target record has been renamed to record-full.
1785 Record/replay is now enabled with the "record full" command.
1786 This also affects settings that are associated with full record/replay
1787 that have been moved from "set/show record" to "set/show record full":
1789 set|show record full insn-number-max
1790 set|show record full stop-at-limit
1791 set|show record full memory-query
1793 * A new record target "record-btrace" has been added. The new target
1794 uses hardware support to record the control-flow of a process. It
1795 does not support replaying the execution, but it implements the
1796 below new commands for investigating the recorded execution log.
1797 This new recording method can be enabled using:
1801 The "record-btrace" target is only available on Intel Atom processors
1802 and requires a Linux kernel 2.6.32 or later.
1804 * Two new commands have been added for record/replay to give information
1805 about the recorded execution without having to replay the execution.
1806 The commands are only supported by "record btrace".
1808 record instruction-history prints the execution history at
1809 instruction granularity
1811 record function-call-history prints the execution history at
1812 function granularity
1814 * New native configurations
1816 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1817 FreeBSD/powerpc powerpc*-*-freebsd
1818 x86_64/Cygwin x86_64-*-cygwin*
1819 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1823 ARM AArch64 aarch64*-*-elf
1824 ARM AArch64 GNU/Linux aarch64*-*-linux
1825 Lynx 178 PowerPC powerpc-*-lynx*178
1826 x86_64/Cygwin x86_64-*-cygwin*
1827 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1829 * If the configured location of system.gdbinit file (as given by the
1830 --with-system-gdbinit option at configure time) is in the
1831 data-directory (as specified by --with-gdb-datadir at configure
1832 time) or in one of its subdirectories, then GDB will look for the
1833 system-wide init file in the directory specified by the
1834 --data-directory command-line option.
1836 * New command line options:
1838 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1839 other initialization files, unlike -nx which disables all of them.
1841 * Removed command line options
1843 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1846 * The 'ptype' and 'whatis' commands now accept an argument to control
1849 * 'info proc' now works on some core files.
1853 ** Vectors can be created with gdb.Type.vector.
1855 ** Python's atexit.register now works in GDB.
1857 ** Types can be pretty-printed via a Python API.
1859 ** Python 3 is now supported (in addition to Python 2.4 or later)
1861 ** New class gdb.Architecture exposes GDB's internal representation
1862 of architecture in the Python API.
1864 ** New method Frame.architecture returns the gdb.Architecture object
1865 corresponding to the frame's architecture.
1867 * New Python-based convenience functions:
1869 ** $_memeq(buf1, buf2, length)
1870 ** $_streq(str1, str2)
1872 ** $_regex(str, regex)
1874 * The 'cd' command now defaults to using '~' (the home directory) if not
1877 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1878 default for GCC since November 2000.
1880 * The command 'forward-search' can now be abbreviated as 'fo'.
1882 * The command 'info tracepoints' can now display 'installed on target'
1883 or 'not installed on target' for each non-pending location of tracepoint.
1885 * New configure options
1887 --enable-libmcheck/--disable-libmcheck
1888 By default, development versions are built with -lmcheck on hosts
1889 that support it, in order to help track memory corruption issues.
1890 Release versions, on the other hand, are built without -lmcheck
1891 by default. The --enable-libmcheck/--disable-libmcheck configure
1892 options allow the user to override that default.
1893 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1894 This configure option allows the user to build GDB with
1895 libbabeltrace using which GDB can read Common Trace Format data.
1897 * New commands (for set/show, see "New options" below)
1900 Catch signals. This is similar to "handle", but allows commands and
1901 conditions to be attached.
1904 List the BFDs known to GDB.
1906 python-interactive [command]
1908 Start a Python interactive prompt, or evaluate the optional command
1909 and print the result of expressions.
1912 "py" is a new alias for "python".
1914 enable type-printer [name]...
1915 disable type-printer [name]...
1916 Enable or disable type printers.
1920 ** For the Renesas Super-H architecture, the "regs" command has been removed
1921 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1926 set print type methods (on|off)
1927 show print type methods
1928 Control whether method declarations are displayed by "ptype".
1929 The default is to show them.
1931 set print type typedefs (on|off)
1932 show print type typedefs
1933 Control whether typedef definitions are displayed by "ptype".
1934 The default is to show them.
1936 set filename-display basename|relative|absolute
1937 show filename-display
1938 Control the way in which filenames is displayed.
1939 The default is "relative", which preserves previous behavior.
1941 set trace-buffer-size
1942 show trace-buffer-size
1943 Request target to change the size of trace buffer.
1945 set remote trace-buffer-size-packet auto|on|off
1946 show remote trace-buffer-size-packet
1947 Control the use of the remote protocol `QTBuffer:size' packet.
1951 Control display of debugging messages related to ARM AArch64.
1954 set debug coff-pe-read
1955 show debug coff-pe-read
1956 Control display of debugging messages related to reading of COFF/PE
1961 Control display of debugging messages related to Mach-O symbols
1964 set debug notification
1965 show debug notification
1966 Control display of debugging info for async remote notification.
1970 ** Command parameter changes are now notified using new async record
1971 "=cmd-param-changed".
1972 ** Trace frame changes caused by command "tfind" are now notified using
1973 new async record "=traceframe-changed".
1974 ** The creation, deletion and modification of trace state variables
1975 are now notified using new async records "=tsv-created",
1976 "=tsv-deleted" and "=tsv-modified".
1977 ** The start and stop of process record are now notified using new
1978 async record "=record-started" and "=record-stopped".
1979 ** Memory changes are now notified using new async record
1981 ** The data-disassemble command response will include a "fullname" field
1982 containing the absolute file name when source has been requested.
1983 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1984 command, to allow pattern filling of memory areas.
1985 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1986 library load/unload events.
1987 ** The response to breakpoint commands and breakpoint async records
1988 includes an "installed" field containing a boolean state about each
1989 non-pending tracepoint location is whether installed on target or not.
1990 ** Output of the "-trace-status" command includes a "trace-file" field
1991 containing the name of the trace file being examined. This field is
1992 optional, and only present when examining a trace file.
1993 ** The "fullname" field is now always present along with the "file" field,
1994 even if the file cannot be found by GDB.
1996 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1997 You must have the LZMA library available when configuring GDB for this
1998 feature to be enabled. For more information, see:
1999 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2001 * New remote packets
2004 Set the size of trace buffer. The remote stub reports support for this
2005 packet to gdb's qSupported query.
2008 Enable Branch Trace Store (BTS)-based branch tracing for the current
2009 thread. The remote stub reports support for this packet to gdb's
2013 Disable branch tracing for the current thread. The remote stub reports
2014 support for this packet to gdb's qSupported query.
2017 Read the traced branches for the current thread. The remote stub
2018 reports support for this packet to gdb's qSupported query.
2020 *** Changes in GDB 7.5
2022 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2023 for more x32 ABI info.
2025 * GDB now supports access to MIPS DSP registers on Linux targets.
2027 * GDB now supports debugging microMIPS binaries.
2029 * The "info os" command on GNU/Linux can now display information on
2030 several new classes of objects managed by the operating system:
2031 "info os procgroups" lists process groups
2032 "info os files" lists file descriptors
2033 "info os sockets" lists internet-domain sockets
2034 "info os shm" lists shared-memory regions
2035 "info os semaphores" lists semaphores
2036 "info os msg" lists message queues
2037 "info os modules" lists loaded kernel modules
2039 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2040 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2041 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2042 options and inspect the probe arguments using the new $_probe_arg family
2043 of convenience variables. You can obtain more information about SystemTap
2044 in <http://sourceware.org/systemtap/>.
2046 * GDB now supports reversible debugging on ARM, it allows you to
2047 debug basic ARM and THUMB instructions, and provides
2048 record/replay support.
2050 * The option "symbol-reloading" has been deleted as it is no longer used.
2054 ** GDB commands implemented in Python can now be put in command class
2057 ** The "maint set python print-stack on|off" is now deleted.
2059 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2060 apply "flag enum"-style pretty-printing to any enum.
2062 ** gdb.lookup_symbol can now work when there is no current frame.
2064 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2065 the source at which the symbol was defined.
2067 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2068 method 'value'. The former indicates whether the symbol needs a
2069 frame in order to compute its value, and the latter computes the
2072 ** A new method 'referenced_value' on gdb.Value objects which can
2073 dereference pointer as well as C++ reference values.
2075 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2076 which return the global and static blocks (as gdb.Block objects),
2077 of the underlying symbol table, respectively.
2079 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2080 object associated with a PC value.
2082 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2083 of the address range occupied by code for the current source line.
2085 * Go language support.
2086 GDB now supports debugging programs written in the Go programming
2089 * GDBserver now supports stdio connections.
2090 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2092 * The binary "gdbtui" can no longer be built or installed.
2093 Use "gdb -tui" instead.
2095 * GDB will now print "flag" enums specially. A flag enum is one where
2096 all the enumerator values have no bits in common when pairwise
2097 "and"ed. When printing a value whose type is a flag enum, GDB will
2098 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2099 (gdb) print (enum E) 3
2102 * The filename part of a linespec will now match trailing components
2103 of a source file name. For example, "break gcc/expr.c:1000" will
2104 now set a breakpoint in build/gcc/expr.c, but not
2105 build/libcpp/expr.c.
2107 * The "info proc" and "generate-core-file" commands will now also
2108 work on remote targets connected to GDBserver on Linux.
2110 * The command "info catch" has been removed. It has been disabled
2111 since December 2007.
2113 * The "catch exception" and "catch assert" commands now accept
2114 a condition at the end of the command, much like the "break"
2115 command does. For instance:
2117 (gdb) catch exception Constraint_Error if Barrier = True
2119 Previously, it was possible to add a condition to such catchpoints,
2120 but it had to be done as a second step, after the catchpoint had been
2121 created, using the "condition" command.
2123 * The "info static-tracepoint-marker" command will now also work on
2124 native Linux targets with in-process agent.
2126 * GDB can now set breakpoints on inlined functions.
2128 * The .gdb_index section has been updated to include symbols for
2129 inlined functions. GDB will ignore older .gdb_index sections by
2130 default, which could cause symbol files to be loaded more slowly
2131 until their .gdb_index sections can be recreated. The new command
2132 "set use-deprecated-index-sections on" will cause GDB to use any older
2133 .gdb_index sections it finds. This will restore performance, but the
2134 ability to set breakpoints on inlined functions will be lost in symbol
2135 files with older .gdb_index sections.
2137 The .gdb_index section has also been updated to record more information
2138 about each symbol. This speeds up the "info variables", "info functions"
2139 and "info types" commands when used with programs having the .gdb_index
2140 section, as well as speeding up debugging with shared libraries using
2141 the .gdb_index section.
2143 * Ada support for GDB/MI Variable Objects has been added.
2145 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2150 ** New command -info-os is the MI equivalent of "info os".
2152 ** Output logs ("set logging" and related) now include MI output.
2156 ** "set use-deprecated-index-sections on|off"
2157 "show use-deprecated-index-sections on|off"
2158 Controls the use of deprecated .gdb_index sections.
2160 ** "catch load" and "catch unload" can be used to stop when a shared
2161 library is loaded or unloaded, respectively.
2163 ** "enable count" can be used to auto-disable a breakpoint after
2166 ** "info vtbl" can be used to show the virtual method tables for
2167 C++ and Java objects.
2169 ** "explore" and its sub commands "explore value" and "explore type"
2170 can be used to recursively explore values and types of
2171 expressions. These commands are available only if GDB is
2172 configured with '--with-python'.
2174 ** "info auto-load" shows status of all kinds of auto-loaded files,
2175 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2176 sequences of commands files, "info auto-load python-scripts"
2177 shows status of auto-loading Python script files,
2178 "info auto-load local-gdbinit" shows status of loading init file
2179 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2180 status of inferior specific thread debugging shared library loading.
2182 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2183 and "show auto-load-scripts" commands have been deprecated, use their
2184 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2185 and "show auto-load python-scripts" counterparts instead.
2187 ** "dprintf location,format,args..." creates a dynamic printf, which
2188 is basically a breakpoint that does a printf and immediately
2189 resumes your program's execution, so it is like a printf that you
2190 can insert dynamically at runtime instead of at compiletime.
2192 ** "set print symbol"
2194 Controls whether GDB attempts to display the symbol, if any,
2195 corresponding to addresses it prints. This defaults to "on", but
2196 you can set it to "off" to restore GDB's previous behavior.
2198 * Deprecated commands
2200 ** For the Renesas Super-H architecture, the "regs" command has been
2201 deprecated, and "info all-registers" should be used instead.
2205 Renesas RL78 rl78-*-elf
2206 HP OpenVMS ia64 ia64-hp-openvms*
2208 * GDBserver supports evaluation of breakpoint conditions. When
2209 support is advertised by GDBserver, GDB may be told to send the
2210 breakpoint conditions in bytecode form to GDBserver. GDBserver
2211 will only report the breakpoint trigger to GDB when its condition
2216 set mips compression
2217 show mips compression
2218 Select the compressed ISA encoding used in functions that have no symbol
2219 information available. The encoding can be set to either of:
2222 and is updated automatically from ELF file flags if available.
2224 set breakpoint condition-evaluation
2225 show breakpoint condition-evaluation
2226 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2227 GDBserver ("target"). Default option "auto" chooses the most efficient
2229 This option can improve debugger efficiency depending on the speed of the
2233 Disable auto-loading globally.
2236 Show auto-loading setting of all kinds of auto-loaded files.
2238 set auto-load gdb-scripts on|off
2239 show auto-load gdb-scripts
2240 Control auto-loading of GDB canned sequences of commands files.
2242 set auto-load python-scripts on|off
2243 show auto-load python-scripts
2244 Control auto-loading of Python script files.
2246 set auto-load local-gdbinit on|off
2247 show auto-load local-gdbinit
2248 Control loading of init file (.gdbinit) from current directory.
2250 set auto-load libthread-db on|off
2251 show auto-load libthread-db
2252 Control auto-loading of inferior specific thread debugging shared library.
2254 set auto-load scripts-directory <dir1>[:<dir2>...]
2255 show auto-load scripts-directory
2256 Set a list of directories from which to load auto-loaded scripts.
2257 Automatically loaded Python scripts and GDB scripts are located in one
2258 of the directories listed by this option.
2259 The delimiter (':' above) may differ according to the host platform.
2261 set auto-load safe-path <dir1>[:<dir2>...]
2262 show auto-load safe-path
2263 Set a list of directories from which it is safe to auto-load files.
2264 The delimiter (':' above) may differ according to the host platform.
2266 set debug auto-load on|off
2267 show debug auto-load
2268 Control display of debugging info for auto-loading the files above.
2270 set dprintf-style gdb|call|agent
2272 Control the way in which a dynamic printf is performed; "gdb"
2273 requests a GDB printf command, while "call" causes dprintf to call a
2274 function in the inferior. "agent" requests that the target agent
2275 (such as GDBserver) do the printing.
2277 set dprintf-function <expr>
2278 show dprintf-function
2279 set dprintf-channel <expr>
2280 show dprintf-channel
2281 Set the function and optional first argument to the call when using
2282 the "call" style of dynamic printf.
2284 set disconnected-dprintf on|off
2285 show disconnected-dprintf
2286 Control whether agent-style dynamic printfs continue to be in effect
2287 after GDB disconnects.
2289 * New configure options
2291 --with-auto-load-dir
2292 Configure default value for the 'set auto-load scripts-directory'
2293 setting above. It defaults to '$debugdir:$datadir/auto-load',
2294 $debugdir representing global debugging info directories (available
2295 via 'show debug-file-directory') and $datadir representing GDB's data
2296 directory (available via 'show data-directory').
2298 --with-auto-load-safe-path
2299 Configure default value for the 'set auto-load safe-path' setting
2300 above. It defaults to the --with-auto-load-dir setting.
2302 --without-auto-load-safe-path
2303 Set 'set auto-load safe-path' to '/', effectively disabling this
2306 * New remote packets
2308 z0/z1 conditional breakpoints extension
2310 The z0/z1 breakpoint insertion packets have been extended to carry
2311 a list of conditional expressions over to the remote stub depending on the
2312 condition evaluation mode. The use of this extension can be controlled
2313 via the "set remote conditional-breakpoints-packet" command.
2317 Specify the signals which the remote stub may pass to the debugged
2318 program without GDB involvement.
2320 * New command line options
2322 --init-command=FILE, -ix Like --command, -x but execute it
2323 before loading inferior.
2324 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2325 execute it before loading inferior.
2327 *** Changes in GDB 7.4
2329 * GDB now handles ambiguous linespecs more consistently; the existing
2330 FILE:LINE support has been expanded to other types of linespecs. A
2331 breakpoint will now be set on all matching locations in all
2332 inferiors, and locations will be added or removed according to
2335 * GDB now allows you to skip uninteresting functions and files when
2336 stepping with the "skip function" and "skip file" commands.
2338 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2339 and "show remote hardware-watchpoint-length-limit". These allows to
2340 set or show the maximum length limit (in bytes) of a remote
2341 target hardware watchpoint.
2343 This allows e.g. to use "unlimited" hardware watchpoints with the
2344 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2345 watchpoints are slower than real hardware watchpoints but are
2346 significantly faster than gdb software watchpoints.
2350 ** The register_pretty_printer function in module gdb.printing now takes
2351 an optional `replace' argument. If True, the new printer replaces any
2354 ** The "maint set python print-stack on|off" command has been
2355 deprecated and will be deleted in GDB 7.5.
2356 A new command: "set python print-stack none|full|message" has
2357 replaced it. Additionally, the default for "print-stack" is
2358 now "message", which just prints the error message without
2361 ** A prompt substitution hook (prompt_hook) is now available to the
2364 ** A new Python module, gdb.prompt has been added to the GDB Python
2365 modules library. This module provides functionality for
2366 escape sequences in prompts (used by set/show
2367 extended-prompt). These escape sequences are replaced by their
2368 corresponding value.
2370 ** Python commands and convenience-functions located in
2371 'data-directory'/python/gdb/command and
2372 'data-directory'/python/gdb/function are now automatically loaded
2375 ** Blocks now provide four new attributes. global_block and
2376 static_block will return the global and static blocks
2377 respectively. is_static and is_global are boolean attributes
2378 that indicate if the block is one of those two types.
2380 ** Symbols now provide the "type" attribute, the type of the symbol.
2382 ** The "gdb.breakpoint" function has been deprecated in favor of
2385 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2386 of a function. This class is based on the "finish" command
2387 available in the CLI.
2389 ** Type objects for struct and union types now allow access to
2390 the fields using standard Python dictionary (mapping) methods.
2391 For example, "some_type['myfield']" now works, as does
2392 "some_type.items()".
2394 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2397 ** A new function, "deep_items" has been added to the gdb.types
2398 module in the GDB Python modules library. This function returns
2399 an iterator over the fields of a struct or union type. Unlike
2400 the standard Python "iteritems" method, it will recursively traverse
2401 any anonymous fields.
2405 ** "*stopped" events can report several new "reason"s, such as
2408 ** Breakpoint changes are now notified using new async records, like
2409 "=breakpoint-modified".
2411 ** New command -ada-task-info.
2413 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2414 $sdir specifies the default system locations of shared libraries.
2415 $pdir specifies the directory where the libpthread used by the application
2418 GDB no longer looks in $sdir and $pdir after it has searched the directories
2419 mentioned in libthread-db-search-path. If you want to search those
2420 directories, they must be specified in libthread-db-search-path.
2421 The default value of libthread-db-search-path on GNU/Linux and Solaris
2422 systems is now "$sdir:$pdir".
2424 $pdir is not supported by gdbserver, it is currently ignored.
2425 $sdir is supported by gdbserver.
2427 * New configure option --with-iconv-bin.
2428 When using the internationalization support like the one in the GNU C
2429 library, GDB will invoke the "iconv" program to get a list of supported
2430 character sets. If this program lives in a non-standard location, one can
2431 use this option to specify where to find it.
2433 * When natively debugging programs on PowerPC BookE processors running
2434 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2435 watchpoints, which specify a mask in addition to an address to watch.
2436 The mask specifies that some bits of an address (the bits which are
2437 reset in the mask) should be ignored when matching the address accessed
2438 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2439 section in the user manual for more details.
2441 * The new option --once causes GDBserver to stop listening for connections once
2442 the first connection is made. The listening port used by GDBserver will
2443 become available after that.
2445 * New commands "info macros" and "alias" have been added.
2447 * New function parameters suffix @entry specifies value of function parameter
2448 at the time the function got called. Entry values are available only since
2454 "!" is now an alias of the "shell" command.
2455 Note that no space is needed between "!" and SHELL COMMAND.
2459 watch EXPRESSION mask MASK_VALUE
2460 The watch command now supports the mask argument which allows creation
2461 of masked watchpoints, if the current architecture supports this feature.
2463 info auto-load-scripts [REGEXP]
2464 This command was formerly named "maintenance print section-scripts".
2465 It is now generally useful and is no longer a maintenance-only command.
2467 info macro [-all] [--] MACRO
2468 The info macro command has new options `-all' and `--'. The first for
2469 printing all definitions of a macro. The second for explicitly specifying
2470 the end of arguments and the beginning of the macro name in case the macro
2471 name starts with a hyphen.
2473 collect[/s] EXPRESSIONS
2474 The tracepoint collect command now takes an optional modifier "/s"
2475 that directs it to dereference pointer-to-character types and
2476 collect the bytes of memory up to a zero byte. The behavior is
2477 similar to what you see when you use the regular print command on a
2478 string. An optional integer following the "/s" sets a bound on the
2479 number of bytes that will be collected.
2482 The trace start command now interprets any supplied arguments as a
2483 note to be recorded with the trace run, with an effect similar to
2484 setting the variable trace-notes.
2487 The trace stop command now interprets any arguments as a note to be
2488 mentioned along with the tstatus report that the trace was stopped
2489 with a command. The effect is similar to setting the variable
2492 * Tracepoints can now be enabled and disabled at any time after a trace
2493 experiment has been started using the standard "enable" and "disable"
2494 commands. It is now possible to start a trace experiment with no enabled
2495 tracepoints; GDB will display a warning, but will allow the experiment to
2496 begin, assuming that tracepoints will be enabled as needed while the trace
2499 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2500 locations with 4-byte instructions, when they were previously
2501 limited to locations with instructions of 5 bytes or longer.
2505 set debug dwarf2-read
2506 show debug dwarf2-read
2507 Turns on or off display of debugging messages related to reading
2508 DWARF debug info. The default is off.
2510 set debug symtab-create
2511 show debug symtab-create
2512 Turns on or off display of debugging messages related to symbol table
2513 creation. The default is off.
2516 show extended-prompt
2517 Set the GDB prompt, and allow escape sequences to be inserted to
2518 display miscellaneous information (see 'help set extended-prompt'
2519 for the list of sequences). This prompt (and any information
2520 accessed through the escape sequences) is updated every time the
2521 prompt is displayed.
2523 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2524 show print entry-values
2525 Set printing of frame argument values at function entry. In some cases
2526 GDB can determine the value of function argument which was passed by the
2527 function caller, even if the value was modified inside the called function.
2529 set debug entry-values
2530 show debug entry-values
2531 Control display of debugging info for determining frame argument values at
2532 function entry and virtual tail call frames.
2534 set basenames-may-differ
2535 show basenames-may-differ
2536 Set whether a source file may have multiple base names.
2537 (A "base name" is the name of a file with the directory part removed.
2538 Example: The base name of "/home/user/hello.c" is "hello.c".)
2539 If set, GDB will canonicalize file names (e.g., expand symlinks)
2540 before comparing them. Canonicalization is an expensive operation,
2541 but it allows the same file be known by more than one base name.
2542 If not set (the default), all source files are assumed to have just
2543 one base name, and gdb will do file name comparisons more efficiently.
2549 Set a user name and notes for the current and any future trace runs.
2550 This is useful for long-running and/or disconnected traces, to
2551 inform others (or yourself) as to who is running the trace, supply
2552 contact information, or otherwise explain what is going on.
2554 set trace-stop-notes
2555 show trace-stop-notes
2556 Set a note attached to the trace run, that is displayed when the
2557 trace has been stopped by a tstop command. This is useful for
2558 instance as an explanation, if you are stopping a trace run that was
2559 started by someone else.
2561 * New remote packets
2565 Dynamically enable a tracepoint in a started trace experiment.
2569 Dynamically disable a tracepoint in a started trace experiment.
2573 Set the user and notes of the trace run.
2577 Query the current status of a tracepoint.
2581 Query the minimum length of instruction at which a fast tracepoint may
2584 * Dcache size (number of lines) and line-size are now runtime-configurable
2585 via "set dcache line" and "set dcache line-size" commands.
2589 Texas Instruments TMS320C6x tic6x-*-*
2593 Renesas RL78 rl78-*-elf
2595 *** Changes in GDB 7.3.1
2597 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2599 *** Changes in GDB 7.3
2601 * GDB has a new command: "thread find [REGEXP]".
2602 It finds the thread id whose name, target id, or thread extra info
2603 matches the given regular expression.
2605 * The "catch syscall" command now works on mips*-linux* targets.
2607 * The -data-disassemble MI command now supports modes 2 and 3 for
2608 dumping the instruction opcodes.
2610 * New command line options
2612 -data-directory DIR Specify DIR as the "data-directory".
2613 This is mostly for testing purposes.
2615 * The "maint set python auto-load on|off" command has been renamed to
2616 "set auto-load-scripts on|off".
2618 * GDB has a new command: "set directories".
2619 It is like the "dir" command except that it replaces the
2620 source path list instead of augmenting it.
2622 * GDB now understands thread names.
2624 On GNU/Linux, "info threads" will display the thread name as set by
2625 prctl or pthread_setname_np.
2627 There is also a new command, "thread name", which can be used to
2628 assign a name internally for GDB to display.
2631 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2632 has been integrated into GDB.
2636 ** The function gdb.Write now accepts an optional keyword 'stream'.
2637 This keyword, when provided, will direct the output to either
2638 stdout, stderr, or GDB's logging output.
2640 ** Parameters can now be be sub-classed in Python, and in particular
2641 you may implement the get_set_doc and get_show_doc functions.
2642 This improves how Parameter set/show documentation is processed
2643 and allows for more dynamic content.
2645 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2646 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2647 have an is_valid method.
2649 ** Breakpoints can now be sub-classed in Python, and in particular
2650 you may implement a 'stop' function that is executed each time
2651 the inferior reaches that breakpoint.
2653 ** New function gdb.lookup_global_symbol looks up a global symbol.
2655 ** GDB values in Python are now callable if the value represents a
2656 function. For example, if 'some_value' represents a function that
2657 takes two integer parameters and returns a value, you can call
2658 that function like so:
2660 result = some_value (10,20)
2662 ** Module gdb.types has been added.
2663 It contains a collection of utilities for working with gdb.Types objects:
2664 get_basic_type, has_field, make_enum_dict.
2666 ** Module gdb.printing has been added.
2667 It contains utilities for writing and registering pretty-printers.
2668 New classes: PrettyPrinter, SubPrettyPrinter,
2669 RegexpCollectionPrettyPrinter.
2670 New function: register_pretty_printer.
2672 ** New commands "info pretty-printers", "enable pretty-printer" and
2673 "disable pretty-printer" have been added.
2675 ** gdb.parameter("directories") is now available.
2677 ** New function gdb.newest_frame returns the newest frame in the
2680 ** The gdb.InferiorThread class has a new "name" attribute. This
2681 holds the thread's name.
2683 ** Python Support for Inferior events.
2684 Python scripts can add observers to be notified of events
2685 occurring in the process being debugged.
2686 The following events are currently supported:
2687 - gdb.events.cont Continue event.
2688 - gdb.events.exited Inferior exited event.
2689 - gdb.events.stop Signal received, and Breakpoint hit events.
2693 ** GDB now puts template parameters in scope when debugging in an
2694 instantiation. For example, if you have:
2696 template<int X> int func (void) { return X; }
2698 then if you step into func<5>, "print X" will show "5". This
2699 feature requires proper debuginfo support from the compiler; it
2700 was added to GCC 4.5.
2702 ** The motion commands "next", "finish", "until", and "advance" now
2703 work better when exceptions are thrown. In particular, GDB will
2704 no longer lose control of the inferior; instead, the GDB will
2705 stop the inferior at the point at which the exception is caught.
2706 This functionality requires a change in the exception handling
2707 code that was introduced in GCC 4.5.
2709 * GDB now follows GCC's rules on accessing volatile objects when
2710 reading or writing target state during expression evaluation.
2711 One notable difference to prior behavior is that "print x = 0"
2712 no longer generates a read of x; the value of the assignment is
2713 now always taken directly from the value being assigned.
2715 * GDB now has some support for using labels in the program's source in
2716 linespecs. For instance, you can use "advance label" to continue
2717 execution to a label.
2719 * GDB now has support for reading and writing a new .gdb_index
2720 section. This section holds a fast index of DWARF debugging
2721 information and can be used to greatly speed up GDB startup and
2722 operation. See the documentation for `save gdb-index' for details.
2724 * The "watch" command now accepts an optional "-location" argument.
2725 When used, this causes GDB to watch the memory referred to by the
2726 expression. Such a watchpoint is never deleted due to it going out
2729 * GDB now supports thread debugging of core dumps on GNU/Linux.
2731 GDB now activates thread debugging using the libthread_db library
2732 when debugging GNU/Linux core dumps, similarly to when debugging
2733 live processes. As a result, when debugging a core dump file, GDB
2734 is now able to display pthread_t ids of threads. For example, "info
2735 threads" shows the same output as when debugging the process when it
2736 was live. In earlier releases, you'd see something like this:
2739 * 1 LWP 6780 main () at main.c:10
2741 While now you see this:
2744 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2746 It is also now possible to inspect TLS variables when debugging core
2749 When debugging a core dump generated on a machine other than the one
2750 used to run GDB, you may need to point GDB at the correct
2751 libthread_db library with the "set libthread-db-search-path"
2752 command. See the user manual for more details on this command.
2754 * When natively debugging programs on PowerPC BookE processors running
2755 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2756 which stop execution of the inferior whenever it executes an instruction
2757 at any address within the specified range. See the "PowerPC Embedded"
2758 section in the user manual for more details.
2760 * New features in the GDB remote stub, GDBserver
2762 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2763 and i686 LynxOS (version 5.x).
2765 ** GDBserver is now supported on Blackfin Linux.
2767 * New native configurations
2769 ia64 HP-UX ia64-*-hpux*
2773 Analog Devices, Inc. Blackfin Processor bfin-*
2775 * Ada task switching is now supported on sparc-elf targets when
2776 debugging a program using the Ravenscar Profile. For more information,
2777 see the "Tasking Support when using the Ravenscar Profile" section
2778 in the GDB user manual.
2780 * Guile support was removed.
2782 * New features in the GNU simulator
2784 ** The --map-info flag lists all known core mappings.
2786 ** CFI flashes may be simulated via the "cfi" device.
2788 *** Changes in GDB 7.2
2790 * Shared library support for remote targets by default
2792 When GDB is configured for a generic, non-OS specific target, like
2793 for example, --target=arm-eabi or one of the many *-*-elf targets,
2794 GDB now queries remote stubs for loaded shared libraries using the
2795 `qXfer:libraries:read' packet. Previously, shared library support
2796 was always disabled for such configurations.
2800 ** Argument Dependent Lookup (ADL)
2802 In C++ ADL lookup directs function search to the namespaces of its
2803 arguments even if the namespace has not been imported.
2813 Here the compiler will search for `foo' in the namespace of 'b'
2814 and find A::foo. GDB now supports this. This construct is commonly
2815 used in the Standard Template Library for operators.
2817 ** Improved User Defined Operator Support
2819 In addition to member operators, GDB now supports lookup of operators
2820 defined in a namespace and imported with a `using' directive, operators
2821 defined in the global scope, operators imported implicitly from an
2822 anonymous namespace, and the ADL operators mentioned in the previous
2824 GDB now also supports proper overload resolution for all the previously
2825 mentioned flavors of operators.
2827 ** static const class members
2829 Printing of static const class members that are initialized in the
2830 class definition has been fixed.
2832 * Windows Thread Information Block access.
2834 On Windows targets, GDB now supports displaying the Windows Thread
2835 Information Block (TIB) structure. This structure is visible either
2836 by using the new command `info w32 thread-information-block' or, by
2837 dereferencing the new convenience variable named `$_tlb', a
2838 thread-specific pointer to the TIB. This feature is also supported
2839 when remote debugging using GDBserver.
2841 * Static tracepoints
2843 Static tracepoints are calls in the user program into a tracing
2844 library. One such library is a port of the LTTng kernel tracer to
2845 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2846 When debugging with GDBserver, GDB now supports combining the GDB
2847 tracepoint machinery with such libraries. For example: the user can
2848 use GDB to probe a static tracepoint marker (a call from the user
2849 program into the tracing library) with the new "strace" command (see
2850 "New commands" below). This creates a "static tracepoint" in the
2851 breakpoint list, that can be manipulated with the same feature set
2852 as fast and regular tracepoints. E.g., collect registers, local and
2853 global variables, collect trace state variables, and define
2854 tracepoint conditions. In addition, the user can collect extra
2855 static tracepoint marker specific data, by collecting the new
2856 $_sdata internal variable. When analyzing the trace buffer, you can
2857 inspect $_sdata like any other variable available to GDB. For more
2858 information, see the "Tracepoints" chapter in GDB user manual. New
2859 remote packets have been defined to support static tracepoints, see
2860 the "New remote packets" section below.
2862 * Better reconstruction of tracepoints after disconnected tracing
2864 GDB will attempt to download the original source form of tracepoint
2865 definitions when starting a trace run, and then will upload these
2866 upon reconnection to the target, resulting in a more accurate
2867 reconstruction of the tracepoints that are in use on the target.
2871 You can now exercise direct control over the ways that GDB can
2872 affect your program. For instance, you can disallow the setting of
2873 breakpoints, so that the program can run continuously (assuming
2874 non-stop mode). In addition, the "observer" variable is available
2875 to switch all of the different controls; in observer mode, GDB
2876 cannot affect the target's behavior at all, which is useful for
2877 tasks like diagnosing live systems in the field.
2879 * The new convenience variable $_thread holds the number of the
2882 * New remote packets
2886 Return the address of the Windows Thread Information Block of a given thread.
2890 In response to several of the tracepoint packets, the target may now
2891 also respond with a number of intermediate `qRelocInsn' request
2892 packets before the final result packet, to have GDB handle
2893 relocating an instruction to execute at a different address. This
2894 is particularly useful for stubs that support fast tracepoints. GDB
2895 reports support for this feature in the qSupported packet.
2899 List static tracepoint markers in the target program.
2903 List static tracepoint markers at a given address in the target
2906 qXfer:statictrace:read
2908 Read the static trace data collected (by a `collect $_sdata'
2909 tracepoint action). The remote stub reports support for this packet
2910 to gdb's qSupported query.
2914 Send the current settings of GDB's permission flags.
2918 Send part of the source (textual) form of a tracepoint definition,
2919 which includes location, conditional, and action list.
2921 * The source command now accepts a -s option to force searching for the
2922 script in the source search path even if the script name specifies
2925 * New features in the GDB remote stub, GDBserver
2927 - GDBserver now support tracepoints (including fast tracepoints, and
2928 static tracepoints). The feature is currently supported by the
2929 i386-linux and amd64-linux builds. See the "Tracepoints support
2930 in gdbserver" section in the manual for more information.
2932 GDBserver JIT compiles the tracepoint's conditional agent
2933 expression bytecode into native code whenever possible for low
2934 overhead dynamic tracepoints conditionals. For such tracepoints,
2935 an expression that examines program state is evaluated when the
2936 tracepoint is reached, in order to determine whether to capture
2937 trace data. If the condition is simple and false, processing the
2938 tracepoint finishes very quickly and no data is gathered.
2940 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2941 for static tracepoints support.
2943 - GDBserver now supports x86_64 Windows 64-bit debugging.
2945 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2946 it understands register description.
2948 * The --batch flag now disables pagination and queries.
2950 * X86 general purpose registers
2952 GDB now supports reading/writing byte, word and double-word x86
2953 general purpose registers directly. This means you can use, say,
2954 $ah or $ax to refer, respectively, to the byte register AH and
2955 16-bit word register AX that are actually portions of the 32-bit
2956 register EAX or 64-bit register RAX.
2958 * The `commands' command now accepts a range of breakpoints to modify.
2959 A plain `commands' following a command that creates multiple
2960 breakpoints affects all the breakpoints set by that command. This
2961 applies to breakpoints set by `rbreak', and also applies when a
2962 single `break' command creates multiple breakpoints (e.g.,
2963 breakpoints on overloaded c++ functions).
2965 * The `rbreak' command now accepts a filename specification as part of
2966 its argument, limiting the functions selected by the regex to those
2967 in the specified file.
2969 * Support for remote debugging Windows and SymbianOS shared libraries
2970 from Unix hosts has been improved. Non Windows GDB builds now can
2971 understand target reported file names that follow MS-DOS based file
2972 system semantics, such as file names that include drive letters and
2973 use the backslash character as directory separator. This makes it
2974 possible to transparently use the "set sysroot" and "set
2975 solib-search-path" on Unix hosts to point as host copies of the
2976 target's shared libraries. See the new command "set
2977 target-file-system-kind" described below, and the "Commands to
2978 specify files" section in the user manual for more information.
2982 eval template, expressions...
2983 Convert the values of one or more expressions under the control
2984 of the string template to a command line, and call it.
2986 set target-file-system-kind unix|dos-based|auto
2987 show target-file-system-kind
2988 Set or show the assumed file system kind for target reported file
2991 save breakpoints <filename>
2992 Save all current breakpoint definitions to a file suitable for use
2993 in a later debugging session. To read the saved breakpoint
2994 definitions, use the `source' command.
2996 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2999 info static-tracepoint-markers
3000 Display information about static tracepoint markers in the target.
3002 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3003 Define a static tracepoint by probing a marker at the given
3004 function, line, address, or marker ID.
3008 Enable and disable observer mode.
3010 set may-write-registers on|off
3011 set may-write-memory on|off
3012 set may-insert-breakpoints on|off
3013 set may-insert-tracepoints on|off
3014 set may-insert-fast-tracepoints on|off
3015 set may-interrupt on|off
3016 Set individual permissions for GDB effects on the target. Note that
3017 some of these settings can have undesirable or surprising
3018 consequences, particularly when changed in the middle of a session.
3019 For instance, disabling the writing of memory can prevent
3020 breakpoints from being inserted, cause single-stepping to fail, or
3021 even crash your program, if you disable after breakpoints have been
3022 inserted. However, GDB should not crash.
3024 set record memory-query on|off
3025 show record memory-query
3026 Control whether to stop the inferior if memory changes caused
3027 by an instruction cannot be recorded.
3032 The disassemble command now supports "start,+length" form of two arguments.
3036 ** GDB now provides a new directory location, called the python directory,
3037 where Python scripts written for GDB can be installed. The location
3038 of that directory is <data-directory>/python, where <data-directory>
3039 is the GDB data directory. For more details, see section `Scripting
3040 GDB using Python' in the manual.
3042 ** The GDB Python API now has access to breakpoints, symbols, symbol
3043 tables, program spaces, inferiors, threads and frame's code blocks.
3044 Additionally, GDB Parameters can now be created from the API, and
3045 manipulated via set/show in the CLI.
3047 ** New functions gdb.target_charset, gdb.target_wide_charset,
3048 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3050 ** New exception gdb.GdbError.
3052 ** Pretty-printers are now also looked up in the current program space.
3054 ** Pretty-printers can now be individually enabled and disabled.
3056 ** GDB now looks for names of Python scripts to auto-load in a
3057 special section named `.debug_gdb_scripts', in addition to looking
3058 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3060 * Tracepoint actions were unified with breakpoint commands. In particular,
3061 there are no longer differences in "info break" output for breakpoints and
3062 tracepoints and the "commands" command can be used for both tracepoints and
3063 regular breakpoints.
3067 ARM Symbian arm*-*-symbianelf*
3069 * D language support.
3070 GDB now supports debugging programs written in the D programming
3073 * GDB now supports the extended ptrace interface for PowerPC which is
3074 available since Linux kernel version 2.6.34. This automatically enables
3075 any hardware breakpoints and additional hardware watchpoints available in
3076 the processor. The old ptrace interface exposes just one hardware
3077 watchpoint and no hardware breakpoints.
3079 * GDB is now able to use the Data Value Compare (DVC) register available on
3080 embedded PowerPC processors to implement in hardware simple watchpoint
3081 conditions of the form:
3083 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3085 This works in native GDB running on Linux kernels with the extended ptrace
3086 interface mentioned above.
3088 *** Changes in GDB 7.1
3092 ** Namespace Support
3094 GDB now supports importing of namespaces in C++. This enables the
3095 user to inspect variables from imported namespaces. Support for
3096 namepace aliasing has also been added. So, if a namespace is
3097 aliased in the current scope (e.g. namepace C=A; ) the user can
3098 print variables using the alias (e.g. (gdb) print C::x).
3102 All known bugs relating to the printing of virtual base class were
3103 fixed. It is now possible to call overloaded static methods using a
3108 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3109 and reinterpret_cast<> are now handled by the C++ expression parser.
3113 Xilinx MicroBlaze microblaze-*-*
3118 Xilinx MicroBlaze microblaze
3121 * Multi-program debugging.
3123 GDB now has support for multi-program (a.k.a. multi-executable or
3124 multi-exec) debugging. This allows for debugging multiple inferiors
3125 simultaneously each running a different program under the same GDB
3126 session. See "Debugging Multiple Inferiors and Programs" in the
3127 manual for more information. This implied some user visible changes
3128 in the multi-inferior support. For example, "info inferiors" now
3129 lists inferiors that are not running yet or that have exited
3130 already. See also "New commands" and "New options" below.
3132 * New tracing features
3134 GDB's tracepoint facility now includes several new features:
3136 ** Trace state variables
3138 GDB tracepoints now include support for trace state variables, which
3139 are variables managed by the target agent during a tracing
3140 experiment. They are useful for tracepoints that trigger each
3141 other, so for instance one tracepoint can count hits in a variable,
3142 and then a second tracepoint has a condition that is true when the
3143 count reaches a particular value. Trace state variables share the
3144 $-syntax of GDB convenience variables, and can appear in both
3145 tracepoint actions and condition expressions. Use the "tvariable"
3146 command to create, and "info tvariables" to view; see "Trace State
3147 Variables" in the manual for more detail.
3151 GDB now includes an option for defining fast tracepoints, which
3152 targets may implement more efficiently, such as by installing a jump
3153 into the target agent rather than a trap instruction. The resulting
3154 speedup can be by two orders of magnitude or more, although the
3155 tradeoff is that some program locations on some target architectures
3156 might not allow fast tracepoint installation, for instance if the
3157 instruction to be replaced is shorter than the jump. To request a
3158 fast tracepoint, use the "ftrace" command, with syntax identical to
3159 the regular trace command.
3161 ** Disconnected tracing
3163 It is now possible to detach GDB from the target while it is running
3164 a trace experiment, then reconnect later to see how the experiment
3165 is going. In addition, a new variable disconnected-tracing lets you
3166 tell the target agent whether to continue running a trace if the
3167 connection is lost unexpectedly.
3171 GDB now has the ability to save the trace buffer into a file, and
3172 then use that file as a target, similarly to you can do with
3173 corefiles. You can select trace frames, print data that was
3174 collected in them, and use tstatus to display the state of the
3175 tracing run at the moment that it was saved. To create a trace
3176 file, use "tsave <filename>", and to use it, do "target tfile
3179 ** Circular trace buffer
3181 You can ask the target agent to handle the trace buffer as a
3182 circular buffer, discarding the oldest trace frames to make room for
3183 newer ones, by setting circular-trace-buffer to on. This feature may
3184 not be available for all target agents.
3189 The disassemble command, when invoked with two arguments, now requires
3190 the arguments to be comma-separated.
3193 The info variables command now displays variable definitions. Files
3194 which only declare a variable are not shown.
3197 The source command is now capable of sourcing Python scripts.
3198 This feature is dependent on the debugger being build with Python
3201 Related to this enhancement is also the introduction of a new command
3202 "set script-extension" (see below).
3204 * New commands (for set/show, see "New options" below)
3206 record save [<FILENAME>]
3207 Save a file (in core file format) containing the process record
3208 execution log for replay debugging at a later time.
3210 record restore <FILENAME>
3211 Restore the process record execution log that was saved at an
3212 earlier time, for replay debugging.
3214 add-inferior [-copies <N>] [-exec <FILENAME>]
3217 clone-inferior [-copies <N>] [ID]
3218 Make a new inferior ready to execute the same program another
3219 inferior has loaded.
3224 maint info program-spaces
3225 List the program spaces loaded into GDB.
3227 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3228 show remote interrupt-sequence
3229 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3230 as the sequence to the remote target in order to interrupt the execution.
3231 Ctrl-C is a default. Some system prefers BREAK which is high level of
3232 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3233 Magic SysRq g. It is BREAK signal and character 'g'.
3235 set remote interrupt-on-connect [on | off]
3236 show remote interrupt-on-connect
3237 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3238 remote target when gdb connects to it. This is needed when you debug
3241 set remotebreak [on | off]
3243 Deprecated. Use "set/show remote interrupt-sequence" instead.
3245 tvariable $NAME [ = EXP ]
3246 Create or modify a trace state variable.
3249 List trace state variables and their values.
3251 delete tvariable $NAME ...
3252 Delete one or more trace state variables.
3255 Evaluate the given expressions without collecting anything into the
3256 trace buffer. (Valid in tracepoint actions only.)
3258 ftrace FN / FILE:LINE / *ADDR
3259 Define a fast tracepoint at the given function, line, or address.
3261 * New expression syntax
3263 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3264 GDB now parses 0b101010 identically with 42.
3268 set follow-exec-mode new|same
3269 show follow-exec-mode
3270 Control whether GDB reuses the same inferior across an exec call or
3271 creates a new one. This is useful to be able to restart the old
3272 executable after the inferior having done an exec call.
3274 set default-collect EXPR, ...
3275 show default-collect
3276 Define a list of expressions to be collected at each tracepoint.
3277 This is a useful way to ensure essential items are not overlooked,
3278 such as registers or a critical global variable.
3280 set disconnected-tracing
3281 show disconnected-tracing
3282 If set to 1, the target is instructed to continue tracing if it
3283 loses its connection to GDB. If 0, the target is to stop tracing
3286 set circular-trace-buffer
3287 show circular-trace-buffer
3288 If set to on, the target is instructed to use a circular trace buffer
3289 and discard the oldest trace frames instead of stopping the trace due
3290 to a full trace buffer. If set to off, the trace stops when the buffer
3291 fills up. Some targets may not support this.
3293 set script-extension off|soft|strict
3294 show script-extension
3295 If set to "off", the debugger does not perform any script language
3296 recognition, and all sourced files are assumed to be GDB scripts.
3297 If set to "soft" (the default), files are sourced according to
3298 filename extension, falling back to GDB scripts if the first
3300 If set to "strict", files are sourced according to filename extension.
3302 set ada trust-PAD-over-XVS on|off
3303 show ada trust-PAD-over-XVS
3304 If off, activate a workaround against a bug in the debugging information
3305 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3306 the GCC sources for more information about the GNAT encoding and
3307 PAD types in particular). It is always safe to set this option to
3308 off, but this introduces a slight performance penalty. The default
3311 * Python API Improvements
3313 ** GDB provides the new class gdb.LazyString. This is useful in
3314 some pretty-printing cases. The new method gdb.Value.lazy_string
3315 provides a simple way to create objects of this type.
3317 ** The fields returned by gdb.Type.fields now have an
3318 `is_base_class' attribute.
3320 ** The new method gdb.Type.range returns the range of an array type.
3322 ** The new method gdb.parse_and_eval can be used to parse and
3323 evaluate an expression.
3325 * New remote packets
3328 Define a trace state variable.
3331 Get the current value of a trace state variable.
3334 Set desired tracing behavior upon disconnection.
3337 Set the trace buffer to be linear or circular.
3340 Get data about the tracepoints currently in use.
3344 Process record now works correctly with hardware watchpoints.
3346 Multiple bug fixes have been made to the mips-irix port, making it
3347 much more reliable. In particular:
3348 - Debugging threaded applications is now possible again. Previously,
3349 GDB would hang while starting the program, or while waiting for
3350 the program to stop at a breakpoint.
3351 - Attaching to a running process no longer hangs.
3352 - An error occurring while loading a core file has been fixed.
3353 - Changing the value of the PC register now works again. This fixes
3354 problems observed when using the "jump" command, or when calling
3355 a function from GDB, or even when assigning a new value to $pc.
3356 - With the "finish" and "return" commands, the return value for functions
3357 returning a small array is now correctly printed.
3358 - It is now possible to break on shared library code which gets executed
3359 during a shared library init phase (code executed while executing
3360 their .init section). Previously, the breakpoint would have no effect.
3361 - GDB is now able to backtrace through the signal handler for
3362 non-threaded programs.
3364 PIE (Position Independent Executable) programs debugging is now supported.
3365 This includes debugging execution of PIC (Position Independent Code) shared
3366 libraries although for that, it should be possible to run such libraries as an
3369 *** Changes in GDB 7.0
3371 * GDB now has an interface for JIT compilation. Applications that
3372 dynamically generate code can create symbol files in memory and register
3373 them with GDB. For users, the feature should work transparently, and
3374 for JIT developers, the interface is documented in the GDB manual in the
3375 "JIT Compilation Interface" chapter.
3377 * Tracepoints may now be conditional. The syntax is as for
3378 breakpoints; either an "if" clause appended to the "trace" command,
3379 or the "condition" command is available. GDB sends the condition to
3380 the target for evaluation using the same bytecode format as is used
3381 for tracepoint actions.
3383 * The disassemble command now supports: an optional /r modifier, print the
3384 raw instructions in hex as well as in symbolic form, and an optional /m
3385 modifier to print mixed source+assembly.
3387 * Process record and replay
3389 In a architecture environment that supports ``process record and
3390 replay'', ``process record and replay'' target can record a log of
3391 the process execution, and replay it with both forward and reverse
3394 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3395 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3396 set execution-direction {forward|reverse}, for targets that support
3399 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3400 feature is available with a native GDB running on kernel version
3403 * GDB now has support for multi-byte and wide character sets on the
3404 target. Strings whose character type is wchar_t, char16_t, or
3405 char32_t are now correctly printed. GDB supports wide- and unicode-
3406 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3407 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3408 `printf'. This feature requires iconv to work properly; if your
3409 system does not have a working iconv, GDB can use GNU libiconv. See
3410 the installation instructions for more information.
3412 * GDB now supports automatic retrieval of shared library files from
3413 remote targets. To use this feature, specify a system root that begins
3414 with the `remote:' prefix, either via the `set sysroot' command or via
3415 the `--with-sysroot' configure-time option.
3417 * "info sharedlibrary" now takes an optional regex of libraries to show,
3418 and it now reports if a shared library has no debugging information.
3420 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3421 now complete on file names.
3423 * When completing in expressions, gdb will attempt to limit
3424 completions to allowable structure or union fields, where appropriate.
3425 For instance, consider:
3427 # struct example { int f1; double f2; };
3428 # struct example variable;
3431 If the user types TAB at the end of this command line, the available
3432 completions will be "f1" and "f2".
3434 * Inlined functions are now supported. They show up in backtraces, and
3435 the "step", "next", and "finish" commands handle them automatically.
3437 * GDB now supports the token-splicing (##) and stringification (#)
3438 operators when expanding macros. It also supports variable-arity
3441 * GDB now supports inspecting extra signal information, exported by
3442 the new $_siginfo convenience variable. The feature is currently
3443 implemented on linux ARM, i386 and amd64.
3445 * GDB can now display the VFP floating point registers and NEON vector
3446 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3447 can provide these registers (requires Linux 2.6.30 or later). Remote
3448 and simulator targets may also provide them.
3450 * New remote packets
3453 Search memory for a sequence of bytes.
3456 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3457 operation over reliable transport links. Use of this packet is
3458 controlled by the `set remote noack-packet' command.
3461 Kill the process with the specified process ID. Use this in preference
3462 to `k' when multiprocess protocol extensions are supported.
3465 Obtains additional operating system information
3469 Read or write additional signal information.
3471 * Removed remote protocol undocumented extension
3473 An undocumented extension to the remote protocol's `S' stop reply
3474 packet that permited the stub to pass a process id was removed.
3475 Remote servers should use the `T' stop reply packet instead.
3477 * GDB now supports multiple function calling conventions according to the
3478 DWARF-2 DW_AT_calling_convention function attribute.
3480 * The SH target utilizes the aforementioned change to distinguish between gcc
3481 and Renesas calling convention. It also adds the new CLI commands
3482 `set/show sh calling-convention'.
3484 * GDB can now read compressed debug sections, as produced by GNU gold
3485 with the --compress-debug-sections=zlib flag.
3487 * 64-bit core files are now supported on AIX.
3489 * Thread switching is now supported on Tru64.
3491 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3492 which will be allocated using malloc later in program execution.
3494 * The qXfer:libraries:read remote procotol packet now allows passing a
3495 list of section offsets.
3497 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3498 conditions handling signals delivered during attach or thread creation
3499 have also been fixed.
3501 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3502 From the user's standpoint, all unqualified instances of True and False
3503 are treated as the standard definitions, regardless of context.
3505 * GDB now parses C++ symbol and type names more flexibly. For
3508 template<typename T> class C { };
3511 GDB will now correctly handle all of:
3513 ptype C<char const *>
3514 ptype C<char const*>
3515 ptype C<const char *>
3516 ptype C<const char*>
3518 * New features in the GDB remote stub, gdbserver
3520 - The "--wrapper" command-line argument tells gdbserver to use a
3521 wrapper program to launch programs for debugging.
3523 - On PowerPC and S/390 targets, it is now possible to use a single
3524 gdbserver executable to debug both 32-bit and 64-bit programs.
3525 (This requires gdbserver itself to be built as a 64-bit executable.)
3527 - gdbserver uses the new noack protocol mode for TCP connections to
3528 reduce communications latency, if also supported and enabled in GDB.
3530 - Support for the sparc64-linux-gnu target is now included in
3533 - The amd64-linux build of gdbserver now supports debugging both
3534 32-bit and 64-bit programs.
3536 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3537 now support hardware watchpoints, and will use them automatically
3542 GDB now has support for scripting using Python. Whether this is
3543 available is determined at configure time.
3545 New GDB commands can now be written in Python.
3547 * Ada tasking support
3549 Ada tasks can now be inspected in GDB. The following commands have
3553 Print the list of Ada tasks.
3555 Print detailed information about task number N.
3557 Print the task number of the current task.
3559 Switch the context of debugging to task number N.
3561 * Support for user-defined prefixed commands. The "define" command can
3562 add new commands to existing prefixes, e.g. "target".
3564 * Multi-inferior, multi-process debugging.
3566 GDB now has generalized support for multi-inferior debugging. See
3567 "Debugging Multiple Inferiors" in the manual for more information.
3568 Although availability still depends on target support, the command
3569 set is more uniform now. The GNU/Linux specific multi-forks support
3570 has been migrated to this new framework. This implied some user
3571 visible changes; see "New commands" and also "Removed commands"
3574 * Target descriptions can now describe the target OS ABI. See the
3575 "Target Description Format" section in the user manual for more
3578 * Target descriptions can now describe "compatible" architectures
3579 to indicate that the target can execute applications for a different
3580 architecture in addition to those for the main target architecture.
3581 See the "Target Description Format" section in the user manual for
3584 * Multi-architecture debugging.
3586 GDB now includes general supports for debugging applications on
3587 hybrid systems that use more than one single processor architecture
3588 at the same time. Each such hybrid architecture still requires
3589 specific support to be added. The only hybrid architecture supported
3590 in this version of GDB is the Cell Broadband Engine.
3592 * GDB now supports integrated debugging of Cell/B.E. applications that
3593 use both the PPU and SPU architectures. To enable support for hybrid
3594 Cell/B.E. debugging, you need to configure GDB to support both the
3595 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3596 --enable-targets configure option.
3598 * Non-stop mode debugging.
3600 For some targets, GDB now supports an optional mode of operation in
3601 which you can examine stopped threads while other threads continue
3602 to execute freely. This is referred to as non-stop mode, with the
3603 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3604 section in the user manual for more information.
3606 To be able to support remote non-stop debugging, a remote stub needs
3607 to implement the non-stop mode remote protocol extensions, as
3608 described in the "Remote Non-Stop" section of the user manual. The
3609 GDB remote stub, gdbserver, has been adjusted to support these
3610 extensions on linux targets.
3612 * New commands (for set/show, see "New options" below)
3614 catch syscall [NAME(S) | NUMBER(S)]
3615 Catch system calls. Arguments, which should be names of system
3616 calls or their numbers, mean catch only those syscalls. Without
3617 arguments, every syscall will be caught. When the inferior issues
3618 any of the specified syscalls, GDB will stop and announce the system
3619 call, both when it is called and when its call returns. This
3620 feature is currently available with a native GDB running on the
3621 Linux Kernel, under the following architectures: x86, x86_64,
3622 PowerPC and PowerPC64.
3624 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3626 Search memory for a sequence of bytes.
3628 maint set python print-stack
3629 maint show python print-stack
3630 Show a stack trace when an error is encountered in a Python script.
3633 Invoke CODE by passing it to the Python interpreter.
3638 These allow macros to be defined, undefined, and listed
3642 Show operating system information about processes.
3645 List the inferiors currently under GDB's control.
3648 Switch focus to inferior number NUM.
3651 Detach from inferior number NUM.
3654 Kill inferior number NUM.
3658 set spu stop-on-load
3659 show spu stop-on-load
3660 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3662 set spu auto-flush-cache
3663 show spu auto-flush-cache
3664 Control whether to automatically flush the software-managed cache
3665 during Cell/B.E. debugging.
3667 set sh calling-convention
3668 show sh calling-convention
3669 Control the calling convention used when calling SH target functions.
3672 show debug timestamp
3673 Control display of timestamps with GDB debugging output.
3675 set disassemble-next-line
3676 show disassemble-next-line
3677 Control display of disassembled source lines or instructions when
3680 set remote noack-packet
3681 show remote noack-packet
3682 Set/show the use of remote protocol QStartNoAckMode packet. See above
3683 under "New remote packets."
3685 set remote query-attached-packet
3686 show remote query-attached-packet
3687 Control use of remote protocol `qAttached' (query-attached) packet.
3689 set remote read-siginfo-object
3690 show remote read-siginfo-object
3691 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3694 set remote write-siginfo-object
3695 show remote write-siginfo-object
3696 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3699 set remote reverse-continue
3700 show remote reverse-continue
3701 Control use of remote protocol 'bc' (reverse-continue) packet.
3703 set remote reverse-step
3704 show remote reverse-step
3705 Control use of remote protocol 'bs' (reverse-step) packet.
3707 set displaced-stepping
3708 show displaced-stepping
3709 Control displaced stepping mode. Displaced stepping is a way to
3710 single-step over breakpoints without removing them from the debuggee.
3711 Also known as "out-of-line single-stepping".
3714 show debug displaced
3715 Control display of debugging info for displaced stepping.
3717 maint set internal-error
3718 maint show internal-error
3719 Control what GDB does when an internal error is detected.
3721 maint set internal-warning
3722 maint show internal-warning
3723 Control what GDB does when an internal warning is detected.
3728 Use a wrapper program to launch programs for debugging.
3730 set multiple-symbols (all|ask|cancel)
3731 show multiple-symbols
3732 The value of this variable can be changed to adjust the debugger behavior
3733 when an expression or a breakpoint location contains an ambiguous symbol
3734 name (an overloaded function name, for instance).
3736 set breakpoint always-inserted
3737 show breakpoint always-inserted
3738 Keep breakpoints always inserted in the target, as opposed to inserting
3739 them when resuming the target, and removing them when the target stops.
3740 This option can improve debugger performance on slow remote targets.
3742 set arm fallback-mode (arm|thumb|auto)
3743 show arm fallback-mode
3744 set arm force-mode (arm|thumb|auto)
3746 These commands control how ARM GDB determines whether instructions
3747 are ARM or Thumb. The default for both settings is auto, which uses
3748 the current CPSR value for instructions without symbols; previous
3749 versions of GDB behaved as if "set arm fallback-mode arm".
3751 set disable-randomization
3752 show disable-randomization
3753 Standalone programs run with the virtual address space randomization enabled
3754 by default on some platforms. This option keeps the addresses stable across
3755 multiple debugging sessions.
3759 Control whether other threads are stopped or not when some thread hits
3764 Requests that asynchronous execution is enabled in the target, if available.
3765 In this case, it's possible to resume target in the background, and interact
3766 with GDB while the target is running. "show target-async" displays the
3767 current state of asynchronous execution of the target.
3769 set target-wide-charset
3770 show target-wide-charset
3771 The target-wide-charset is the name of the character set that GDB
3772 uses when printing characters whose type is wchar_t.
3774 set tcp auto-retry (on|off)
3776 set tcp connect-timeout
3777 show tcp connect-timeout
3778 These commands allow GDB to retry failed TCP connections to a remote stub
3779 with a specified timeout period; this is useful if the stub is launched
3780 in parallel with GDB but may not be ready to accept connections immediately.
3782 set libthread-db-search-path
3783 show libthread-db-search-path
3784 Control list of directories which GDB will search for appropriate
3787 set schedule-multiple (on|off)
3788 show schedule-multiple
3789 Allow GDB to resume all threads of all processes or only threads of
3790 the current process.
3794 Use more aggressive caching for accesses to the stack. This improves
3795 performance of remote debugging (particularly backtraces) without
3796 affecting correctness.
3798 set interactive-mode (on|off|auto)
3799 show interactive-mode
3800 Control whether GDB runs in interactive mode (on) or not (off).
3801 When in interactive mode, GDB waits for the user to answer all
3802 queries. Otherwise, GDB does not wait and assumes the default
3803 answer. When set to auto (the default), GDB determines which
3804 mode to use based on the stdin settings.
3809 For program forks, this is replaced by the new more generic `info
3810 inferiors' command. To list checkpoints, you can still use the
3811 `info checkpoints' command, which was an alias for the `info forks'
3815 Replaced by the new `inferior' command. To switch between
3816 checkpoints, you can still use the `restart' command, which was an
3817 alias for the `fork' command.
3820 This is removed, since some targets don't have a notion of
3821 processes. To switch between processes, you can still use the
3822 `inferior' command using GDB's own inferior number.
3825 For program forks, this is replaced by the new more generic `kill
3826 inferior' command. To delete a checkpoint, you can still use the
3827 `delete checkpoint' command, which was an alias for the `delete
3831 For program forks, this is replaced by the new more generic `detach
3832 inferior' command. To detach a checkpoint, you can still use the
3833 `detach checkpoint' command, which was an alias for the `detach
3836 * New native configurations
3838 x86/x86_64 Darwin i[34567]86-*-darwin*
3840 x86_64 MinGW x86_64-*-mingw*
3844 Lattice Mico32 lm32-*
3845 x86 DICOS i[34567]86-*-dicos*
3846 x86_64 DICOS x86_64-*-dicos*
3849 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3850 (mingw32ce) debugging.
3856 These commands were actually not implemented on any target.
3858 *** Changes in GDB 6.8
3860 * New native configurations
3862 NetBSD/hppa hppa*-*netbsd*
3863 Xtensa GNU/Linux xtensa*-*-linux*
3867 NetBSD/hppa hppa*-*-netbsd*
3868 Xtensa GNU/Lunux xtensa*-*-linux*
3870 * Change in command line behavior -- corefiles vs. process ids.
3872 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3873 attaching to process NUMBER fails, GDB no longer attempts to open a
3874 core file named NUMBER. Attaching to a program using the -c option
3875 is no longer supported. Instead, use the '-p' or '--pid' options.
3877 * GDB can now be built as a native debugger for debugging Windows x86
3878 (mingw32) Portable Executable (PE) programs.
3880 * Pending breakpoints no longer change their number when their address
3883 * GDB now supports breakpoints with multiple locations,
3884 including breakpoints on C++ constructors, inside C++ templates,
3885 and in inlined functions.
3887 * GDB's ability to debug optimized code has been improved. GDB more
3888 accurately identifies function bodies and lexical blocks that occupy
3889 more than one contiguous range of addresses.
3891 * Target descriptions can now describe registers for PowerPC.
3893 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3894 registers on PowerPC targets.
3896 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3897 targets even when the libthread_db library is not available.
3899 * The GDB remote stub, gdbserver, now supports the new file transfer
3900 commands (remote put, remote get, and remote delete).
3902 * The GDB remote stub, gdbserver, now supports run and attach in
3903 extended-remote mode.
3905 * hppa*64*-*-hpux11* target broken
3906 The debugger is unable to start a program and fails with the following
3907 error: "Error trying to get information about dynamic linker".
3908 The gdb-6.7 release is also affected.
3910 * GDB now supports the --enable-targets= configure option to allow
3911 building a single GDB executable that supports multiple remote
3912 target architectures.
3914 * GDB now supports debugging C and C++ programs which use the
3915 Decimal Floating Point extension. In addition, the PowerPC target
3916 now has a set of pseudo-registers to inspect decimal float values
3917 stored in two consecutive float registers.
3919 * The -break-insert MI command can optionally create pending
3922 * Improved support for debugging Ada
3923 Many improvements to the Ada language support have been made. These
3925 - Better support for Ada2005 interface types
3926 - Improved handling of arrays and slices in general
3927 - Better support for Taft-amendment types
3928 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3930 - Improved command completion in Ada
3933 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3938 set print frame-arguments (all|scalars|none)
3939 show print frame-arguments
3940 The value of this variable can be changed to control which argument
3941 values should be printed by the debugger when displaying a frame.
3946 Transfer files to and from a remote target, and delete remote files.
3953 Transfer files to and from a remote target, and delete remote files.
3955 * New remote packets
3962 Open, close, read, write, and delete files on the remote system.
3965 Attach to an existing process on the remote system, in extended-remote
3969 Run a new process on the remote system, in extended-remote mode.
3971 *** Changes in GDB 6.7
3973 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3974 bfd, libiberty and opcodes, as revealed by static analysis donated by
3975 Coverity, Inc. (http://scan.coverity.com).
3977 * When looking up multiply-defined global symbols, GDB will now prefer the
3978 symbol definition in the current shared library if it was built using the
3979 -Bsymbolic linker option.
3981 * When the Text User Interface (TUI) is not configured, GDB will now
3982 recognize the -tui command-line option and print a message that the TUI
3985 * The GDB remote stub, gdbserver, now has lower overhead for high
3986 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3988 * GDB for MIPS targets now autodetects whether a remote target provides
3989 32-bit or 64-bit register values.
3991 * Support for C++ member pointers has been improved.
3993 * GDB now understands XML target descriptions, which specify the
3994 target's overall architecture. GDB can read a description from
3995 a local file or over the remote serial protocol.
3997 * Vectors of single-byte data use a new integer type which is not
3998 automatically displayed as character or string data.
4000 * The /s format now works with the print command. It displays
4001 arrays of single-byte integers and pointers to single-byte integers
4004 * Target descriptions can now describe target-specific registers,
4005 for architectures which have implemented the support (currently
4006 only ARM, M68K, and MIPS).
4008 * GDB and the GDB remote stub, gdbserver, now support the XScale
4011 * The GDB remote stub, gdbserver, has been updated to support
4012 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4013 has been rewritten to use the standard GDB remote protocol.
4015 * GDB can now step into C++ functions which are called through thunks.
4017 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4019 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4020 layout. It also supports a TextSeg= and DataSeg= response when only
4021 segment base addresses (rather than offsets) are available.
4023 * The /i format now outputs any trailing branch delay slot instructions
4024 immediately following the last instruction within the count specified.
4026 * The GDB remote protocol "T" stop reply packet now supports a
4027 "library" response. Combined with the new "qXfer:libraries:read"
4028 packet, this response allows GDB to debug shared libraries on targets
4029 where the operating system manages the list of loaded libraries (e.g.
4030 Windows and SymbianOS).
4032 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4033 (DLLs) on Windows and Windows CE targets.
4035 * GDB now supports a faster verification that a .debug file matches its binary
4036 according to its build-id signature, if the signature is present.
4042 Enable or disable hardware flow control (RTS/CTS) on the serial port
4043 when debugging using remote targets.
4045 set mem inaccessible-by-default
4046 show mem inaccessible-by-default
4047 If the target supplies a memory map, for instance via the remote
4048 protocol's "qXfer:memory-map:read" packet, setting this variable
4049 prevents GDB from accessing memory outside the memory map. This
4050 is useful for targets with memory mapped registers or which react
4051 badly to accesses of unmapped address space.
4053 set breakpoint auto-hw
4054 show breakpoint auto-hw
4055 If the target supplies a memory map, for instance via the remote
4056 protocol's "qXfer:memory-map:read" packet, setting this variable
4057 lets GDB use hardware breakpoints automatically for memory regions
4058 where it can not use software breakpoints. This covers both the
4059 "break" command and internal breakpoints used for other commands
4060 including "next" and "finish".
4063 catch exception unhandled
4064 Stop the program execution when Ada exceptions are raised.
4067 Stop the program execution when an Ada assertion failed.
4071 Set an alternate system root for target files. This is a more
4072 general version of "set solib-absolute-prefix", which is now
4073 an alias to "set sysroot".
4076 Provide extended SPU facility status information. This set of
4077 commands is available only when debugging the Cell/B.E. SPU
4080 * New native configurations
4082 OpenBSD/sh sh*-*openbsd*
4085 unset tdesc filename
4087 Use the specified local file as an XML target description, and do
4088 not query the target for its built-in description.
4092 OpenBSD/sh sh*-*-openbsd*
4093 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4094 Toshiba Media Processor mep-elf
4096 * New remote packets
4099 Ignore the specified signals; pass them directly to the debugged program
4100 without stopping other threads or reporting them to GDB.
4102 qXfer:features:read:
4103 Read an XML target description from the target, which describes its
4108 Read or write contents of an spufs file on the target system. These
4109 packets are available only on the Cell/B.E. SPU architecture.
4111 qXfer:libraries:read:
4112 Report the loaded shared libraries. Combined with new "T" packet
4113 response, this packet allows GDB to debug shared libraries on
4114 targets where the operating system manages the list of loaded
4115 libraries (e.g. Windows and SymbianOS).
4119 Support for these obsolete configurations has been removed.
4127 i[34567]86-*-lynxos*
4128 i[34567]86-*-netware*
4129 i[34567]86-*-sco3.2v5*
4130 i[34567]86-*-sco3.2v4*
4132 i[34567]86-*-sysv4.2*
4135 i[34567]86-*-unixware2*
4136 i[34567]86-*-unixware*
4145 * Other removed features
4152 Various m68k-only ROM monitors.
4159 Various Renesas ROM monitors and debugging interfaces for SH and
4164 Support for a Macraigor serial interface to on-chip debugging.
4165 GDB does not directly support the newer parallel or USB
4170 A debug information format. The predecessor to DWARF 2 and
4171 DWARF 3, which are still supported.
4173 Support for the HP aCC compiler on HP-UX/PA-RISC
4175 SOM-encapsulated symbolic debugging information, automatic
4176 invocation of pxdb, and the aCC custom C++ ABI. This does not
4177 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4178 with aCC can still be debugged on an assembly level.
4180 MIPS ".pdr" sections
4182 A MIPS-specific format used to describe stack frame layout
4183 in debugging information.
4187 GDB could work with an older version of Guile to debug
4188 the interpreter and Scheme programs running in it.
4190 set mips stack-arg-size
4191 set mips saved-gpreg-size
4193 Use "set mips abi" to control parameter passing for MIPS.
4195 *** Changes in GDB 6.6
4200 Cell Broadband Engine SPU spu-elf
4202 * GDB can now be configured as a cross-debugger targeting native Windows
4203 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4204 running on a Windows system over TCP/IP to debug Windows programs.
4206 * The GDB remote stub, gdbserver, has been updated to support Windows and
4207 Cygwin debugging. Both single-threaded and multi-threaded programs are
4210 * The "set trust-readonly-sections" command works again. This command was
4211 broken in GDB 6.3, 6.4, and 6.5.
4213 * The "load" command now supports writing to flash memory, if the remote
4214 stub provides the required support.
4216 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4217 longer requires symbolic debug information (e.g. DWARF-2).
4222 unset substitute-path
4223 show substitute-path
4224 Manage a list of substitution rules that GDB uses to rewrite the name
4225 of the directories where the sources are located. This can be useful
4226 for instance when the sources were moved to a different location
4227 between compilation and debugging.
4231 Print each CLI command as it is executed. Each command is prefixed with
4232 a number of `+' symbols representing the nesting depth.
4233 The source command now has a `-v' option to enable the same feature.
4237 The ARM Demon monitor support (RDP protocol, "target rdp").
4239 Kernel Object Display, an embedded debugging feature which only worked with
4240 an obsolete version of Cisco IOS.
4242 The 'set download-write-size' and 'show download-write-size' commands.
4244 * New remote packets
4247 Tell a stub about GDB client features, and request remote target features.
4248 The first feature implemented is PacketSize, which allows the target to
4249 specify the size of packets it can handle - to minimize the number of
4250 packets required and improve performance when connected to a remote
4254 Fetch an OS auxilliary vector from the remote stub. This packet is a
4255 more efficient replacement for qPart:auxv:read.
4257 qXfer:memory-map:read:
4258 Fetch a memory map from the remote stub, including information about
4259 RAM, ROM, and flash memory devices.
4264 Erase and program a flash memory device.
4266 * Removed remote packets
4269 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4270 used it, and only gdbserver implemented it.
4272 *** Changes in GDB 6.5
4276 Renesas M32C/M16C m32c-elf
4278 Morpho Technologies ms1 ms1-elf
4282 init-if-undefined Initialize a convenience variable, but
4283 only if it doesn't already have a value.
4285 The following commands are presently only implemented for native GNU/Linux:
4287 checkpoint Save a snapshot of the program state.
4289 restart <n> Return the program state to a
4290 previously saved state.
4292 info checkpoints List currently saved checkpoints.
4294 delete-checkpoint <n> Delete a previously saved checkpoint.
4296 set|show detach-on-fork Tell gdb whether to detach from a newly
4297 forked process, or to keep debugging it.
4299 info forks List forks of the user program that
4300 are available to be debugged.
4302 fork <n> Switch to debugging one of several
4303 forks of the user program that are
4304 available to be debugged.
4306 delete-fork <n> Delete a fork from the list of forks
4307 that are available to be debugged (and
4308 kill the forked process).
4310 detach-fork <n> Delete a fork from the list of forks
4311 that are available to be debugged (and
4312 allow the process to continue).
4316 Morpho Technologies ms2 ms1-elf
4318 * Improved Windows host support
4320 GDB now builds as a cross debugger hosted on i686-mingw32, including
4321 native console support, and remote communications using either
4322 network sockets or serial ports.
4324 * Improved Modula-2 language support
4326 GDB can now print most types in the Modula-2 syntax. This includes:
4327 basic types, set types, record types, enumerated types, range types,
4328 pointer types and ARRAY types. Procedure var parameters are correctly
4329 printed and hexadecimal addresses and character constants are also
4330 written in the Modula-2 syntax. Best results can be obtained by using
4331 GNU Modula-2 together with the -gdwarf-2 command line option.
4335 The ARM rdi-share module.
4337 The Netware NLM debug server.
4339 *** Changes in GDB 6.4
4341 * New native configurations
4343 OpenBSD/arm arm*-*-openbsd*
4344 OpenBSD/mips64 mips64-*-openbsd*
4348 Morpho Technologies ms1 ms1-elf
4350 * New command line options
4352 --batch-silent As for --batch, but totally silent.
4353 --return-child-result The debugger will exist with the same value
4354 the child (debugged) program exited with.
4355 --eval-command COMMAND, -ex COMMAND
4356 Execute a single GDB CLI command. This may be
4357 specified multiple times and in conjunction
4358 with the --command (-x) option.
4360 * Deprecated commands removed
4362 The following commands, that were deprecated in 2000, have been
4366 set|show arm disassembly-flavor set|show arm disassembler
4367 othernames set arm disassembler
4368 set|show remotedebug set|show debug remote
4369 set|show archdebug set|show debug arch
4370 set|show eventdebug set|show debug event
4373 * New BSD user-level threads support
4375 It is now possible to debug programs using the user-level threads
4376 library on OpenBSD and FreeBSD. Currently supported (target)
4379 FreeBSD/amd64 x86_64-*-freebsd*
4380 FreeBSD/i386 i386-*-freebsd*
4381 OpenBSD/i386 i386-*-openbsd*
4383 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4384 are not yet supported.
4386 * New support for Matsushita MN10300 w/sim added
4387 (Work in progress). mn10300-elf.
4389 * REMOVED configurations and files
4391 VxWorks and the XDR protocol *-*-vxworks
4392 Motorola MCORE mcore-*-*
4393 National Semiconductor NS32000 ns32k-*-*
4395 * New "set print array-indexes" command
4397 After turning this setting "on", GDB prints the index of each element
4398 when displaying arrays. The default is "off" to preserve the previous
4401 * VAX floating point support
4403 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4405 * User-defined command support
4407 In addition to using $arg0..$arg9 for argument passing, it is now possible
4408 to use $argc to determine now many arguments have been passed. See the
4409 section on user-defined commands in the user manual for more information.
4411 *** Changes in GDB 6.3:
4413 * New command line option
4415 GDB now accepts -l followed by a number to set the timeout for remote
4418 * GDB works with GCC -feliminate-dwarf2-dups
4420 GDB now supports a more compact representation of DWARF-2 debug
4421 information using DW_FORM_ref_addr references. These are produced
4422 by GCC with the option -feliminate-dwarf2-dups and also by some
4423 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4424 to use -feliminate-dwarf2-dups.
4426 * Internationalization
4428 When supported by the host system, GDB will be built with
4429 internationalization (libintl). The task of marking up the sources is
4430 continued, we're looking forward to our first translation.
4434 Initial support for debugging programs compiled with the GNAT
4435 implementation of the Ada programming language has been integrated
4436 into GDB. In this release, support is limited to expression evaluation.
4438 * New native configurations
4440 GNU/Linux/m32r m32r-*-linux-gnu
4444 GDB's remote protocol now includes support for the 'p' packet. This
4445 packet is used to fetch individual registers from a remote inferior.
4447 * END-OF-LIFE registers[] compatibility module
4449 GDB's internal register infrastructure has been completely rewritten.
4450 The new infrastructure making possible the implementation of key new
4451 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4454 GDB 6.3 will be the last release to include the the registers[]
4455 compatibility module that allowed out-of-date configurations to
4456 continue to work. This change directly impacts the following
4466 powerpc bdm protocol
4468 Unless there is activity to revive these configurations, they will be
4469 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4471 * OBSOLETE configurations and files
4473 Configurations that have been declared obsolete in this release have
4474 been commented out. Unless there is activity to revive these
4475 configurations, the next release of GDB will have their sources
4476 permanently REMOVED.
4485 *** Changes in GDB 6.2.1:
4487 * MIPS `break main; run' gave an heuristic-fence-post warning
4489 When attempting to run even a simple program, a warning about
4490 heuristic-fence-post being hit would be reported. This problem has
4493 * MIPS IRIX 'long double' crashed GDB
4495 When examining a long double variable, GDB would get a segmentation
4496 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4497 IRIX long double values).
4501 A bug in the VAX stack code was causing problems with the "next"
4502 command. This problem has been fixed.
4504 *** Changes in GDB 6.2:
4506 * Fix for ``many threads''
4508 On GNU/Linux systems that use the NPTL threads library, a program
4509 rapidly creating and deleting threads would confuse GDB leading to the
4512 ptrace: No such process.
4513 thread_db_get_info: cannot get thread info: generic error
4515 This problem has been fixed.
4517 * "-async" and "-noasync" options removed.
4519 Support for the broken "-noasync" option has been removed (it caused
4522 * New ``start'' command.
4524 This command runs the program until the begining of the main procedure.
4526 * New BSD Kernel Data Access Library (libkvm) interface
4528 Using ``target kvm'' it is now possible to debug kernel core dumps and
4529 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4530 platforms. Currently supported (native-only) configurations are:
4532 FreeBSD/amd64 x86_64-*-freebsd*
4533 FreeBSD/i386 i?86-*-freebsd*
4534 NetBSD/i386 i?86-*-netbsd*
4535 NetBSD/m68k m68*-*-netbsd*
4536 NetBSD/sparc sparc-*-netbsd*
4537 OpenBSD/amd64 x86_64-*-openbsd*
4538 OpenBSD/i386 i?86-*-openbsd*
4539 OpenBSD/m68k m68*-openbsd*
4540 OpenBSD/sparc sparc-*-openbsd*
4542 * Signal trampoline code overhauled
4544 Many generic problems with GDB's signal handling code have been fixed.
4545 These include: backtraces through non-contiguous stacks; recognition
4546 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4547 call; backtrace through a signal trampoline; step into and out of
4548 signal handlers; and single-stepping in the signal trampoline.
4550 Please note that kernel bugs are a limiting factor here. These
4551 features have been shown to work on an s390 GNU/Linux system that
4552 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4554 * Cygwin support for DWARF 2 added.
4556 * New native configurations
4558 GNU/Linux/hppa hppa*-*-linux*
4559 OpenBSD/hppa hppa*-*-openbsd*
4560 OpenBSD/m68k m68*-*-openbsd*
4561 OpenBSD/m88k m88*-*-openbsd*
4562 OpenBSD/powerpc powerpc-*-openbsd*
4563 NetBSD/vax vax-*-netbsd*
4564 OpenBSD/vax vax-*-openbsd*
4566 * END-OF-LIFE frame compatibility module
4568 GDB's internal frame infrastructure has been completely rewritten.
4569 The new infrastructure making it possible to support key new features
4570 including DWARF 2 Call Frame Information. To aid in the task of
4571 migrating old configurations to this new infrastructure, a
4572 compatibility module, that allowed old configurations to continue to
4573 work, was also included.
4575 GDB 6.2 will be the last release to include this frame compatibility
4576 module. This change directly impacts the following configurations:
4586 Unless there is activity to revive these configurations, they will be
4587 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4589 * REMOVED configurations and files
4591 Sun 3, running SunOS 3 m68*-*-sunos3*
4592 Sun 3, running SunOS 4 m68*-*-sunos4*
4593 Sun 2, running SunOS 3 m68000-*-sunos3*
4594 Sun 2, running SunOS 4 m68000-*-sunos4*
4595 Motorola 680x0 running LynxOS m68*-*-lynxos*
4596 AT&T 3b1/Unix pc m68*-att-*
4597 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4598 decstation mips-dec-* mips-little-*
4599 riscos mips-*-riscos* mips-*-sysv*
4600 sonymips mips-sony-*
4601 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4603 *** Changes in GDB 6.1.1:
4605 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4607 The TUI (Text-mode User Interface) is now built as part of a default
4608 GDB configuration. It is enabled by either selecting the TUI with the
4609 command line option "-i=tui" or by running the separate "gdbtui"
4610 program. For more information on the TUI, see the manual "Debugging
4613 * Pending breakpoint support (also included in GDB 6.1)
4615 Support has been added to allow you to specify breakpoints in shared
4616 libraries that have not yet been loaded. If a breakpoint location
4617 cannot be found, and the "breakpoint pending" option is set to auto,
4618 GDB queries you if you wish to make the breakpoint pending on a future
4619 shared-library load. If and when GDB resolves the breakpoint symbol,
4620 the pending breakpoint is removed as one or more regular breakpoints
4623 Pending breakpoints are very useful for GCJ Java debugging.
4625 * Fixed ISO-C build problems
4627 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4628 non ISO-C code that stopped them being built using a more strict ISO-C
4629 compiler (e.g., IBM's C compiler).
4631 * Fixed build problem on IRIX 5
4633 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4634 wasn't able to compile compile on an IRIX 5 system.
4636 * Added execute permission to gdb/gdbserver/configure
4638 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4639 permission. This bug would cause configure to fail on a number of
4640 systems (Solaris, IRIX). Ref: server/519.
4642 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4644 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4645 has been updated to use constant array sizes.
4647 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4649 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4650 its generated DWARF Call Frame Info. This encoding was causing GDB to
4651 panic, that panic has been fixed. Ref: gdb/1628.
4653 * Fixed a problem when examining parameters in shared library code.
4655 When examining parameters in optimized shared library code generated
4656 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4657 not available''. GDB now correctly displays the variable's value.
4659 *** Changes in GDB 6.1:
4661 * Removed --with-mmalloc
4663 Support for the mmalloc memory manager has been removed, as it
4664 conflicted with the internal gdb byte cache.
4666 * Changes in AMD64 configurations
4668 The AMD64 target now includes the %cs and %ss registers. As a result
4669 the AMD64 remote protocol has changed; this affects the floating-point
4670 and SSE registers. If you rely on those registers for your debugging,
4671 you should upgrade gdbserver on the remote side.
4673 * Revised SPARC target
4675 The SPARC target has been completely revised, incorporating the
4676 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4677 support for LynxOS and SunOS 4 has been dropped. Calling functions
4678 from within GDB on operating systems with a non-executable stack
4679 (Solaris, OpenBSD) now works.
4683 GDB has a new C++ demangler which does a better job on the mangled
4684 names generated by current versions of g++. It also runs faster, so
4685 with this and other changes gdb should now start faster on large C++
4688 * DWARF 2 Location Expressions
4690 GDB support for location expressions has been extended to support function
4691 arguments and frame bases. Older versions of GDB could crash when they
4694 * C++ nested types and namespaces
4696 GDB's support for nested types and namespaces in C++ has been
4697 improved, especially if you use the DWARF 2 debugging format. (This
4698 is the default for recent versions of GCC on most platforms.)
4699 Specifically, if you have a class "Inner" defined within a class or
4700 namespace "Outer", then GDB realizes that the class's name is
4701 "Outer::Inner", not simply "Inner". This should greatly reduce the
4702 frequency of complaints about not finding RTTI symbols. In addition,
4703 if you are stopped at inside of a function defined within a namespace,
4704 GDB modifies its name lookup accordingly.
4706 * New native configurations
4708 NetBSD/amd64 x86_64-*-netbsd*
4709 OpenBSD/amd64 x86_64-*-openbsd*
4710 OpenBSD/alpha alpha*-*-openbsd*
4711 OpenBSD/sparc sparc-*-openbsd*
4712 OpenBSD/sparc64 sparc64-*-openbsd*
4714 * New debugging protocols
4716 M32R with SDI protocol m32r-*-elf*
4718 * "set prompt-escape-char" command deleted.
4720 The command "set prompt-escape-char" has been deleted. This command,
4721 and its very obscure effet on GDB's prompt, was never documented,
4722 tested, nor mentioned in the NEWS file.
4724 * OBSOLETE configurations and files
4726 Configurations that have been declared obsolete in this release have
4727 been commented out. Unless there is activity to revive these
4728 configurations, the next release of GDB will have their sources
4729 permanently REMOVED.
4731 Sun 3, running SunOS 3 m68*-*-sunos3*
4732 Sun 3, running SunOS 4 m68*-*-sunos4*
4733 Sun 2, running SunOS 3 m68000-*-sunos3*
4734 Sun 2, running SunOS 4 m68000-*-sunos4*
4735 Motorola 680x0 running LynxOS m68*-*-lynxos*
4736 AT&T 3b1/Unix pc m68*-att-*
4737 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4738 decstation mips-dec-* mips-little-*
4739 riscos mips-*-riscos* mips-*-sysv*
4740 sonymips mips-sony-*
4741 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4743 * REMOVED configurations and files
4745 SGI Irix-4.x mips-sgi-irix4 or iris4
4746 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4747 Z8000 simulator z8k-zilog-none or z8ksim
4748 Matsushita MN10200 w/simulator mn10200-*-*
4749 H8/500 simulator h8500-hitachi-hms or h8500hms
4750 HP/PA running BSD hppa*-*-bsd*
4751 HP/PA running OSF/1 hppa*-*-osf*
4752 HP/PA Pro target hppa*-*-pro*
4753 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4754 386BSD i[3456]86-*-bsd*
4755 Sequent family i[3456]86-sequent-sysv4*
4756 i[3456]86-sequent-sysv*
4757 i[3456]86-sequent-bsd*
4758 SPARC running LynxOS sparc-*-lynxos*
4759 SPARC running SunOS 4 sparc-*-sunos4*
4760 Tsqware Sparclet sparclet-*-*
4761 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4763 *** Changes in GDB 6.0:
4767 Support for debugging the Objective-C programming language has been
4768 integrated into GDB.
4770 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4772 DWARF 2's Call Frame Information makes available compiler generated
4773 information that more exactly describes the program's run-time stack.
4774 By using this information, GDB is able to provide more robust stack
4777 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4778 have been updated to use a new backtrace mechanism which includes
4779 DWARF 2 CFI support.
4783 GDB's remote protocol has been extended to include support for hosted
4784 file I/O (where the remote target uses GDB's file system). See GDB's
4785 remote protocol documentation for details.
4787 * All targets using the new architecture framework.
4789 All of GDB's targets have been updated to use the new internal
4790 architecture framework. The way is now open for future GDB releases
4791 to include cross-architecture native debugging support (i386 on amd64,
4794 * GNU/Linux's Thread Local Storage (TLS)
4796 GDB now includes support for for the GNU/Linux implementation of
4797 per-thread variables.
4799 * GNU/Linux's Native POSIX Thread Library (NPTL)
4801 GDB's thread code has been updated to work with either the new
4802 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4804 * Separate debug info.
4806 GDB, in conjunction with BINUTILS, now supports a mechanism for
4807 automatically loading debug information from a separate file. Instead
4808 of shipping full debug and non-debug versions of system libraries,
4809 system integrators can now instead ship just the stripped libraries
4810 and optional debug files.
4812 * DWARF 2 Location Expressions
4814 DWARF 2 Location Expressions allow the compiler to more completely
4815 describe the location of variables (even in optimized code) to the
4818 GDB now includes preliminary support for location expressions (support
4819 for DW_OP_piece is still missing).
4823 A number of long standing bugs that caused GDB to die while starting a
4824 Java application have been fixed. GDB's Java support is now
4825 considered "useable".
4827 * GNU/Linux support for fork, vfork, and exec.
4829 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4830 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4833 * GDB supports logging output to a file
4835 There are two new commands, "set logging" and "show logging", which can be
4836 used to capture GDB's output to a file.
4838 * The meaning of "detach" has changed for gdbserver
4840 The "detach" command will now resume the application, as documented. To
4841 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4844 * d10v, m68hc11 `regs' command deprecated
4846 The `info registers' command has been updated so that it displays the
4847 registers using a format identical to the old `regs' command.
4851 A new command, "maint set profile on/off", has been added. This command can
4852 be used to enable or disable profiling while running GDB, to profile a
4853 session or a set of commands. In addition there is a new configure switch,
4854 "--enable-profiling", which will cause GDB to be compiled with profiling
4855 data, for more informative profiling results.
4857 * Default MI syntax changed to "mi2".
4859 The default MI (machine interface) syntax, enabled by the command line
4860 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4861 "mi1", can be enabled by specifying the option "-i=mi1".
4863 Support for the original "mi0" syntax (included in GDB 5.0) has been
4866 Fix for gdb/192: removed extraneous space when displaying frame level.
4867 Fix for gdb/672: update changelist is now output in mi list format.
4868 Fix for gdb/702: a -var-assign that updates the value now shows up
4869 in a subsequent -var-update.
4871 * New native configurations.
4873 FreeBSD/amd64 x86_64-*-freebsd*
4875 * Multi-arched targets.
4877 HP/PA HPUX11 hppa*-*-hpux*
4878 Renesas M32R/D w/simulator m32r-*-elf*
4880 * OBSOLETE configurations and files
4882 Configurations that have been declared obsolete in this release have
4883 been commented out. Unless there is activity to revive these
4884 configurations, the next release of GDB will have their sources
4885 permanently REMOVED.
4887 Z8000 simulator z8k-zilog-none or z8ksim
4888 Matsushita MN10200 w/simulator mn10200-*-*
4889 H8/500 simulator h8500-hitachi-hms or h8500hms
4890 HP/PA running BSD hppa*-*-bsd*
4891 HP/PA running OSF/1 hppa*-*-osf*
4892 HP/PA Pro target hppa*-*-pro*
4893 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4894 Sequent family i[3456]86-sequent-sysv4*
4895 i[3456]86-sequent-sysv*
4896 i[3456]86-sequent-bsd*
4897 Tsqware Sparclet sparclet-*-*
4898 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4900 * REMOVED configurations and files
4903 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4904 IBM AIX PS/2 i[3456]86-*-aix
4905 i386 running Mach 3.0 i[3456]86-*-mach3*
4906 i386 running Mach i[3456]86-*-mach*
4907 i386 running OSF/1 i[3456]86-*osf1mk*
4908 HP/Apollo 68k Family m68*-apollo*-sysv*,
4910 m68*-hp-bsd*, m68*-hp-hpux*
4911 Argonaut Risc Chip (ARC) arc-*-*
4912 Mitsubishi D30V d30v-*-*
4913 Fujitsu FR30 fr30-*-elf*
4914 OS/9000 i[34]86-*-os9k
4915 I960 with MON960 i960-*-coff
4917 * MIPS $fp behavior changed
4919 The convenience variable $fp, for the MIPS, now consistently returns
4920 the address of the current frame's base. Previously, depending on the
4921 context, $fp could refer to either $sp or the current frame's base
4922 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4923 The GNU Source-Level Debugger''.
4925 *** Changes in GDB 5.3:
4927 * GNU/Linux shared library multi-threaded performance improved.
4929 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4930 `/proc', in preference to `ptrace' for memory reads. This may result
4931 in an improvement in the start-up time of multi-threaded, shared
4932 library applications when run under GDB. One GDB user writes: ``loads
4933 shared libs like mad''.
4935 * ``gdbserver'' now supports multi-threaded applications on some targets
4937 Support for debugging multi-threaded applications which use
4938 the GNU/Linux LinuxThreads package has been added for
4939 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4940 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4942 * GDB now supports C/C++ preprocessor macros.
4944 GDB now expands preprocessor macro invocations in C/C++ expressions,
4945 and provides various commands for showing macro definitions and how
4948 The new command `macro expand EXPRESSION' expands any macro
4949 invocations in expression, and shows the result.
4951 The new command `show macro MACRO-NAME' shows the definition of the
4952 macro named MACRO-NAME, and where it was defined.
4954 Most compilers don't include information about macros in the debugging
4955 information by default. In GCC 3.1, for example, you need to compile
4956 your program with the options `-gdwarf-2 -g3'. If the macro
4957 information is present in the executable, GDB will read it.
4959 * Multi-arched targets.
4961 DEC Alpha (partial) alpha*-*-*
4962 DEC VAX (partial) vax-*-*
4964 National Semiconductor NS32000 (partial) ns32k-*-*
4965 Motorola 68000 (partial) m68k-*-*
4966 Motorola MCORE mcore-*-*
4970 Fujitsu FRV architecture added by Red Hat frv*-*-*
4973 * New native configurations
4975 Alpha NetBSD alpha*-*-netbsd*
4976 SH NetBSD sh*-*-netbsdelf*
4977 MIPS NetBSD mips*-*-netbsd*
4978 UltraSPARC NetBSD sparc64-*-netbsd*
4980 * OBSOLETE configurations and files
4982 Configurations that have been declared obsolete in this release have
4983 been commented out. Unless there is activity to revive these
4984 configurations, the next release of GDB will have their sources
4985 permanently REMOVED.
4987 Mitsubishi D30V d30v-*-*
4988 OS/9000 i[34]86-*-os9k
4989 IBM AIX PS/2 i[3456]86-*-aix
4990 Fujitsu FR30 fr30-*-elf*
4991 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4992 Argonaut Risc Chip (ARC) arc-*-*
4993 i386 running Mach 3.0 i[3456]86-*-mach3*
4994 i386 running Mach i[3456]86-*-mach*
4995 i386 running OSF/1 i[3456]86-*osf1mk*
4996 HP/Apollo 68k Family m68*-apollo*-sysv*,
4998 m68*-hp-bsd*, m68*-hp-hpux*
4999 I960 with MON960 i960-*-coff
5001 * OBSOLETE languages
5003 CHILL, a Pascal like language used by telecommunications companies.
5005 * REMOVED configurations and files
5007 AMD 29k family via UDI a29k-amd-udi, udi29k
5008 A29K VxWorks a29k-*-vxworks
5009 AMD 29000 embedded, using EBMON a29k-none-none
5010 AMD 29000 embedded with COFF a29k-none-coff
5011 AMD 29000 embedded with a.out a29k-none-aout
5013 testsuite/gdb.hp/gdb.threads-hp/ directory
5015 * New command "set max-user-call-depth <nnn>"
5017 This command allows the user to limit the call depth of user-defined
5018 commands. The default is 1024.
5020 * Changes in FreeBSD/i386 native debugging.
5022 Support for the "generate-core-file" has been added.
5024 * New commands "dump", "append", and "restore".
5026 These commands allow data to be copied from target memory
5027 to a bfd-format or binary file (dump and append), and back
5028 from a file into memory (restore).
5030 * Improved "next/step" support on multi-processor Alpha Tru64.
5032 The previous single-step mechanism could cause unpredictable problems,
5033 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5034 of a software single-step mechanism prevents this.
5036 *** Changes in GDB 5.2.1:
5044 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5045 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5046 Fix, by Joel Brobecker imported from mainline.
5048 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5049 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5050 Fix, by Fred Fish, imported from mainline.
5052 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5053 Surprisingly enough, it works now.
5054 By Michal Ludvig, imported from mainline.
5056 i386 hardware watchpoint support:
5057 avoid misses on second run for some targets.
5058 By Pierre Muller, imported from mainline.
5060 *** Changes in GDB 5.2:
5062 * New command "set trust-readonly-sections on[off]".
5064 This command is a hint that tells gdb that read-only sections
5065 really are read-only (ie. that their contents will not change).
5066 In this mode, gdb will go to the object file rather than the
5067 target to read memory from read-only sections (such as ".text").
5068 This can be a significant performance improvement on some
5069 (notably embedded) targets.
5071 * New command "generate-core-file" (or "gcore").
5073 This new gdb command allows the user to drop a core file of the child
5074 process state at any time. So far it's been implemented only for
5075 GNU/Linux and Solaris, but should be relatively easily ported to other
5076 hosts. Argument is core file name (defaults to core.<pid>).
5078 * New command line option
5080 GDB now accepts --pid or -p followed by a process id.
5082 * Change in command line behavior -- corefiles vs. process ids.
5084 There is a subtle behavior in the way in which GDB handles
5085 command line arguments. The first non-flag argument is always
5086 a program to debug, but the second non-flag argument may either
5087 be a corefile or a process id. Previously, GDB would attempt to
5088 open the second argument as a corefile, and if that failed, would
5089 issue a superfluous error message and then attempt to attach it as
5090 a process. Now, if the second argument begins with a non-digit,
5091 it will be treated as a corefile. If it begins with a digit,
5092 GDB will attempt to attach it as a process, and if no such process
5093 is found, will then attempt to open it as a corefile.
5095 * Changes in ARM configurations.
5097 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5098 configuration is fully multi-arch.
5100 * New native configurations
5102 ARM NetBSD arm*-*-netbsd*
5103 x86 OpenBSD i[3456]86-*-openbsd*
5104 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5105 Sparc64 running FreeBSD sparc64-*-freebsd*
5109 Sanyo XStormy16 xstormy16-elf
5111 * OBSOLETE configurations and files
5113 Configurations that have been declared obsolete in this release have
5114 been commented out. Unless there is activity to revive these
5115 configurations, the next release of GDB will have their sources
5116 permanently REMOVED.
5118 AMD 29k family via UDI a29k-amd-udi, udi29k
5119 A29K VxWorks a29k-*-vxworks
5120 AMD 29000 embedded, using EBMON a29k-none-none
5121 AMD 29000 embedded with COFF a29k-none-coff
5122 AMD 29000 embedded with a.out a29k-none-aout
5124 testsuite/gdb.hp/gdb.threads-hp/ directory
5126 * REMOVED configurations and files
5128 TI TMS320C80 tic80-*-*
5130 PowerPC Solaris powerpcle-*-solaris*
5131 PowerPC Windows NT powerpcle-*-cygwin32
5132 PowerPC Netware powerpc-*-netware*
5133 Harris/CXUX m88k m88*-harris-cxux*
5134 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5135 ns32k-utek-sysv* ns32k-utek-*
5136 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5137 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5138 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5139 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5140 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5142 * Changes to command line processing
5144 The new `--args' feature can be used to specify command-line arguments
5145 for the inferior from gdb's command line.
5147 * Changes to key bindings
5149 There is a new `operate-and-get-next' function bound to `C-o'.
5151 *** Changes in GDB 5.1.1
5153 Fix compile problem on DJGPP.
5155 Fix a problem with floating-point registers on the i386 being
5158 Fix to stop GDB crashing on .debug_str debug info.
5160 Numerous documentation fixes.
5162 Numerous testsuite fixes.
5164 *** Changes in GDB 5.1:
5166 * New native configurations
5168 Alpha FreeBSD alpha*-*-freebsd*
5169 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5170 MIPS GNU/Linux mips*-*-linux*
5171 MIPS SGI Irix 6.x mips*-sgi-irix6*
5172 ia64 AIX ia64-*-aix*
5173 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5177 Motorola 68HC11 and 68HC12 m68hc11-elf
5179 UltraSparc running GNU/Linux sparc64-*-linux*
5181 * OBSOLETE configurations and files
5183 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5184 Harris/CXUX m88k m88*-harris-cxux*
5185 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5186 ns32k-utek-sysv* ns32k-utek-*
5187 TI TMS320C80 tic80-*-*
5189 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5190 PowerPC Solaris powerpcle-*-solaris*
5191 PowerPC Windows NT powerpcle-*-cygwin32
5192 PowerPC Netware powerpc-*-netware*
5193 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5194 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5195 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5196 Apple Macintosh (MPW) host N/A
5198 stuff.c (Program to stuff files into a specially prepared space in kdb)
5199 kdb-start.c (Main loop for the standalone kernel debugger)
5201 Configurations that have been declared obsolete in this release have
5202 been commented out. Unless there is activity to revive these
5203 configurations, the next release of GDB will have their sources
5204 permanently REMOVED.
5206 * REMOVED configurations and files
5208 Altos 3068 m68*-altos-*
5209 Convex c1-*-*, c2-*-*
5211 ARM RISCix arm-*-* (as host)
5215 * GDB has been converted to ISO C.
5217 GDB's source code has been converted to ISO C. In particular, the
5218 sources are fully protoized, and rely on standard headers being
5223 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5225 * The MI enabled by default.
5227 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5228 revised and enabled by default. Packages which use GDB as a debugging
5229 engine behind a UI or another front end are encouraged to switch to
5230 using the GDB/MI interface, instead of the old annotations interface
5231 which is now deprecated.
5233 * Support for debugging Pascal programs.
5235 GDB now includes support for debugging Pascal programs. The following
5236 main features are supported:
5238 - Pascal-specific data types such as sets;
5240 - automatic recognition of Pascal sources based on file-name
5243 - Pascal-style display of data types, variables, and functions;
5245 - a Pascal expression parser.
5247 However, some important features are not yet supported.
5249 - Pascal string operations are not supported at all;
5251 - there are some problems with boolean types;
5253 - Pascal type hexadecimal constants are not supported
5254 because they conflict with the internal variables format;
5256 - support for Pascal objects and classes is not full yet;
5258 - unlike Pascal, GDB is case-sensitive for symbol names.
5260 * Changes in completion.
5262 Commands such as `shell', `run' and `set args', which pass arguments
5263 to inferior programs, now complete on file names, similar to what
5264 users expect at the shell prompt.
5266 Commands which accept locations, such as `disassemble', `print',
5267 `breakpoint', `until', etc. now complete on filenames as well as
5268 program symbols. Thus, if you type "break foob TAB", and the source
5269 files linked into the programs include `foobar.c', that file name will
5270 be one of the candidates for completion. However, file names are not
5271 considered for completion after you typed a colon that delimits a file
5272 name from a name of a function in that file, as in "break foo.c:bar".
5274 `set demangle-style' completes on available demangling styles.
5276 * New platform-independent commands:
5278 It is now possible to define a post-hook for a command as well as a
5279 hook that runs before the command. For more details, see the
5280 documentation of `hookpost' in the GDB manual.
5282 * Changes in GNU/Linux native debugging.
5284 Support for debugging multi-threaded programs has been completely
5285 revised for all platforms except m68k and sparc. You can now debug as
5286 many threads as your system allows you to have.
5288 Attach/detach is supported for multi-threaded programs.
5290 Support for SSE registers was added for x86. This doesn't work for
5291 multi-threaded programs though.
5293 * Changes in MIPS configurations.
5295 Multi-arch support is enabled for all MIPS configurations.
5297 GDB can now be built as native debugger on SGI Irix 6.x systems for
5298 debugging n32 executables. (Debugging 64-bit executables is not yet
5301 * Unified support for hardware watchpoints in all x86 configurations.
5303 Most (if not all) native x86 configurations support hardware-assisted
5304 breakpoints and watchpoints in a unified manner. This support
5305 implements debug register sharing between watchpoints, which allows to
5306 put a virtually infinite number of watchpoints on the same address,
5307 and also supports watching regions up to 16 bytes with several debug
5310 The new maintenance command `maintenance show-debug-regs' toggles
5311 debugging print-outs in functions that insert, remove, and test
5312 watchpoints and hardware breakpoints.
5314 * Changes in the DJGPP native configuration.
5316 New command ``info dos sysinfo'' displays assorted information about
5317 the CPU, OS, memory, and DPMI server.
5319 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5320 display information about segment descriptors stored in GDT, LDT, and
5323 New commands ``info dos pde'' and ``info dos pte'' display entries
5324 from Page Directory and Page Tables (for now works with CWSDPMI only).
5325 New command ``info dos address-pte'' displays the Page Table entry for
5326 a given linear address.
5328 GDB can now pass command lines longer than 126 characters to the
5329 program being debugged (requires an update to the libdbg.a library
5330 which is part of the DJGPP development kit).
5332 DWARF2 debug info is now supported.
5334 It is now possible to `step' and `next' through calls to `longjmp'.
5336 * Changes in documentation.
5338 All GDB documentation was converted to GFDL, the GNU Free
5339 Documentation License.
5341 Tracepoints-related commands are now fully documented in the GDB
5344 TUI, the Text-mode User Interface, is now documented in the manual.
5346 Tracepoints-related commands are now fully documented in the GDB
5349 The "GDB Internals" manual now has an index. It also includes
5350 documentation of `ui_out' functions, GDB coding standards, x86
5351 hardware watchpoints, and memory region attributes.
5353 * GDB's version number moved to ``version.in''
5355 The Makefile variable VERSION has been replaced by the file
5356 ``version.in''. People creating GDB distributions should update the
5357 contents of this file.
5361 GUD support is now a standard part of the EMACS distribution.
5363 *** Changes in GDB 5.0:
5365 * Improved support for debugging FP programs on x86 targets
5367 Unified and much-improved support for debugging floating-point
5368 programs on all x86 targets. In particular, ``info float'' now
5369 displays the FP registers in the same format on all x86 targets, with
5370 greater level of detail.
5372 * Improvements and bugfixes in hardware-assisted watchpoints
5374 It is now possible to watch array elements, struct members, and
5375 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5376 on x86 targets no longer erroneously trigger when the address is
5379 * Improvements in the native DJGPP version of GDB
5381 The distribution now includes all the scripts and auxiliary files
5382 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5383 machines ``out of the box''.
5385 The DJGPP version can now debug programs that use signals. It is
5386 possible to catch signals that happened in the debuggee, deliver
5387 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5388 would kill the program being debugged.) Programs that hook hardware
5389 interrupts (keyboard, timer, etc.) can also be debugged.
5391 It is now possible to debug DJGPP programs that redirect their
5392 standard handles or switch them to raw (as opposed to cooked) mode, or
5393 even close them. The command ``run < foo > bar'' works as expected,
5394 and ``info terminal'' reports useful information about the debuggee's
5395 terminal, including raw/cooked mode, redirection, etc.
5397 The DJGPP version now uses termios functions for console I/O, which
5398 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5401 DOS-style file names with drive letters are now fully supported by
5404 It is now possible to debug DJGPP programs that switch their working
5405 directory. It is also possible to rerun the debuggee any number of
5406 times without restarting GDB; thus, you can use the same setup,
5407 breakpoints, etc. for many debugging sessions.
5409 * New native configurations
5411 ARM GNU/Linux arm*-*-linux*
5412 PowerPC GNU/Linux powerpc-*-linux*
5416 Motorola MCore mcore-*-*
5417 x86 VxWorks i[3456]86-*-vxworks*
5418 PowerPC VxWorks powerpc-*-vxworks*
5419 TI TMS320C80 tic80-*-*
5421 * OBSOLETE configurations
5423 Altos 3068 m68*-altos-*
5424 Convex c1-*-*, c2-*-*
5426 ARM RISCix arm-*-* (as host)
5429 Configurations that have been declared obsolete will be commented out,
5430 but the code will be left in place. If there is no activity to revive
5431 these configurations before the next release of GDB, the sources will
5432 be permanently REMOVED.
5434 * Gould support removed
5436 Support for the Gould PowerNode and NP1 has been removed.
5438 * New features for SVR4
5440 On SVR4 native platforms (such as Solaris), if you attach to a process
5441 without first loading a symbol file, GDB will now attempt to locate and
5442 load symbols from the running process's executable file.
5444 * Many C++ enhancements
5446 C++ support has been greatly improved. Overload resolution now works properly
5447 in almost all cases. RTTI support is on the way.
5449 * Remote targets can connect to a sub-program
5451 A popen(3) style serial-device has been added. This device starts a
5452 sub-process (such as a stand-alone simulator) and then communicates
5453 with that. The sub-program to run is specified using the syntax
5454 ``|<program> <args>'' vis:
5456 (gdb) set remotedebug 1
5457 (gdb) target extended-remote |mn10300-elf-sim program-args
5459 * MIPS 64 remote protocol
5461 A long standing bug in the mips64 remote protocol where by GDB
5462 expected certain 32 bit registers (ex SR) to be transfered as 32
5463 instead of 64 bits has been fixed.
5465 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5466 added to provide backward compatibility with older versions of GDB.
5468 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5470 The command ``set remotebinarydownload'' command has been replaced by
5471 ``set remote X-packet''. Other commands in ``set remote'' family
5472 include ``set remote P-packet''.
5474 * Breakpoint commands accept ranges.
5476 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5477 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5478 ``tracepoint passcount'' also accepts a range of tracepoints.
5480 * ``apropos'' command added.
5482 The ``apropos'' command searches through command names and
5483 documentation strings, printing out matches, making it much easier to
5484 try to find a command that does what you are looking for.
5488 A new machine oriented interface (MI) has been added to GDB. This
5489 interface is designed for debug environments running GDB as a separate
5490 process. This is part of the long term libGDB project. See the
5491 "GDB/MI" chapter of the GDB manual for further information. It can be
5492 enabled by configuring with:
5494 .../configure --enable-gdbmi
5496 *** Changes in GDB-4.18:
5498 * New native configurations
5500 HP-UX 10.20 hppa*-*-hpux10.20
5501 HP-UX 11.x hppa*-*-hpux11.0*
5502 M68K GNU/Linux m68*-*-linux*
5506 Fujitsu FR30 fr30-*-elf*
5507 Intel StrongARM strongarm-*-*
5508 Mitsubishi D30V d30v-*-*
5510 * OBSOLETE configurations
5512 Gould PowerNode, NP1 np1-*-*, pn-*-*
5514 Configurations that have been declared obsolete will be commented out,
5515 but the code will be left in place. If there is no activity to revive
5516 these configurations before the next release of GDB, the sources will
5517 be permanently REMOVED.
5521 As a compatibility experiment, GDB's source files buildsym.h and
5522 buildsym.c have been converted to pure standard C, no longer
5523 containing any K&R compatibility code. We believe that all systems in
5524 use today either come with a standard C compiler, or have a GCC port
5525 available. If this is not true, please report the affected
5526 configuration to bug-gdb@gnu.org immediately. See the README file for
5527 information about getting a standard C compiler if you don't have one
5532 GDB now uses readline 2.2.
5534 * set extension-language
5536 You can now control the mapping between filename extensions and source
5537 languages by using the `set extension-language' command. For instance,
5538 you can ask GDB to treat .c files as C++ by saying
5539 set extension-language .c c++
5540 The command `info extensions' lists all of the recognized extensions
5541 and their associated languages.
5543 * Setting processor type for PowerPC and RS/6000
5545 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5546 you can use the `set processor' command to specify what variant of the
5547 PowerPC family you are debugging. The command
5551 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5552 following PowerPC and RS6000 variants:
5554 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5555 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5557 403GC IBM PowerPC 403GC
5558 505 Motorola PowerPC 505
5559 860 Motorola PowerPC 860 or 850
5560 601 Motorola PowerPC 601
5561 602 Motorola PowerPC 602
5562 603 Motorola/IBM PowerPC 603 or 603e
5563 604 Motorola PowerPC 604 or 604e
5564 750 Motorola/IBM PowerPC 750 or 750
5566 At the moment, this command just tells GDB what to name the
5567 special-purpose processor registers. Since almost all the affected
5568 registers are inaccessible to user-level programs, this command is
5569 only useful for remote debugging in its present form.
5573 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5574 more extensive support for HP-UX. Added features include shared
5575 library support, kernel threads and hardware watchpoints for 11.00,
5576 support for HP's ANSI C and C++ compilers, and a compatibility mode
5577 for xdb and dbx commands.
5581 HP's donation includes the new concept of catchpoints, which is a
5582 generalization of the old catch command. On HP-UX, it is now possible
5583 to catch exec, fork, and vfork, as well as library loading.
5585 This means that the existing catch command has changed; its first
5586 argument now specifies the type of catch to be set up. See the
5587 output of "help catch" for a list of catchpoint types.
5589 * Debugging across forks
5591 On HP-UX, you can choose which process to debug when a fork() happens
5596 HP has donated a curses-based terminal user interface (TUI). To get
5597 it, build with --enable-tui. Although this can be enabled for any
5598 configuration, at present it only works for native HP debugging.
5600 * GDB remote protocol additions
5602 A new protocol packet 'X' that writes binary data is now available.
5603 Default behavior is to try 'X', then drop back to 'M' if the stub
5604 fails to respond. The settable variable `remotebinarydownload'
5605 allows explicit control over the use of 'X'.
5607 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5608 full 64-bit address. The command
5610 set remoteaddresssize 32
5612 can be used to revert to the old behaviour. For existing remote stubs
5613 the change should not be noticed, as the additional address information
5616 In order to assist in debugging stubs, you may use the maintenance
5617 command `packet' to send any text string to the stub. For instance,
5619 maint packet heythere
5621 sends the packet "$heythere#<checksum>". Note that it is very easy to
5622 disrupt a debugging session by sending the wrong packet at the wrong
5625 The compare-sections command allows you to compare section data on the
5626 target to what is in the executable file without uploading or
5627 downloading, by comparing CRC checksums.
5629 * Tracing can collect general expressions
5631 You may now collect general expressions at tracepoints. This requires
5632 further additions to the target-side stub; see tracepoint.c and
5633 doc/agentexpr.texi for further details.
5635 * mask-address variable for Mips
5637 For Mips targets, you may control the zeroing of the upper 32 bits of
5638 a 64-bit address by entering `set mask-address on'. This is mainly
5639 of interest to users of embedded R4xxx and R5xxx processors.
5641 * Higher serial baud rates
5643 GDB's serial code now allows you to specify baud rates 57600, 115200,
5644 230400, and 460800 baud. (Note that your host system may not be able
5645 to achieve all of these rates.)
5649 The i960 configuration now includes an initial implementation of a
5650 builtin simulator, contributed by Jim Wilson.
5653 *** Changes in GDB-4.17:
5655 * New native configurations
5657 Alpha GNU/Linux alpha*-*-linux*
5658 Unixware 2.x i[3456]86-unixware2*
5659 Irix 6.x mips*-sgi-irix6*
5660 PowerPC GNU/Linux powerpc-*-linux*
5661 PowerPC Solaris powerpcle-*-solaris*
5662 Sparc GNU/Linux sparc-*-linux*
5663 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5667 Argonaut Risc Chip (ARC) arc-*-*
5668 Hitachi H8/300S h8300*-*-*
5669 Matsushita MN10200 w/simulator mn10200-*-*
5670 Matsushita MN10300 w/simulator mn10300-*-*
5671 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5672 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5673 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5674 Mitsubishi D10V w/simulator d10v-*-*
5675 Mitsubishi M32R/D w/simulator m32r-*-elf*
5676 Tsqware Sparclet sparclet-*-*
5677 NEC V850 w/simulator v850-*-*
5679 * New debugging protocols
5681 ARM with RDI protocol arm*-*-*
5682 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5683 DDB and LSI variants of PMON protocol mips*-*-*
5684 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5685 PowerPC with SDS protocol powerpc{,le}-*-eabi
5686 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5690 All configurations can now understand and use the DWARF 2 debugging
5691 format. The choice is automatic, if the symbol file contains DWARF 2
5696 GDB now includes basic Java language support. This support is
5697 only useful with Java compilers that produce native machine code.
5699 * solib-absolute-prefix and solib-search-path
5701 For SunOS and SVR4 shared libraries, you may now set the prefix for
5702 loading absolute shared library symbol files, and the search path for
5703 locating non-absolute shared library symbol files.
5705 * Live range splitting
5707 GDB can now effectively debug code for which GCC has performed live
5708 range splitting as part of its optimization. See gdb/doc/LRS for
5709 more details on the expected format of the stabs information.
5713 GDB's support for the GNU Hurd, including thread debugging, has been
5714 updated to work with current versions of the Hurd.
5718 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5719 instruction set. ARM GDB automatically detects when Thumb
5720 instructions are in use, and adjusts disassembly and backtracing
5725 GDB's MIPS target configurations now handle the MIP16 16-bit
5730 GDB now includes support for overlays; if an executable has been
5731 linked such that multiple sections are based at the same address, GDB
5732 will decide which section to use for symbolic info. You can choose to
5733 control the decision manually, using overlay commands, or implement
5734 additional target-side support and use "overlay load-target" to bring
5735 in the overlay mapping. Do "help overlay" for more detail.
5739 The command "info symbol <address>" displays information about
5740 the symbol at the specified address.
5744 The standard remote protocol now includes an extension that allows
5745 asynchronous collection and display of trace data. This requires
5746 extensive support in the target-side debugging stub. Tracing mode
5747 includes a new interaction mode in GDB and new commands: see the
5748 file tracepoint.c for more details.
5752 Configurations for embedded MIPS now include a simulator contributed
5753 by Cygnus Solutions. The simulator supports the instruction sets
5754 of most MIPS variants.
5758 Sparc configurations may now include the ERC32 simulator contributed
5759 by the European Space Agency. The simulator is not built into
5760 Sparc targets by default; configure with --enable-sim to include it.
5764 For target configurations that may include multiple variants of a
5765 basic architecture (such as MIPS and SH), you may now set the
5766 architecture explicitly. "set arch" sets, "info arch" lists
5767 the possible architectures.
5769 *** Changes in GDB-4.16:
5771 * New native configurations
5773 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5774 M68K NetBSD m68k-*-netbsd*
5775 PowerPC AIX 4.x powerpc-*-aix*
5776 PowerPC MacOS powerpc-*-macos*
5777 PowerPC Windows NT powerpcle-*-cygwin32
5778 RS/6000 AIX 4.x rs6000-*-aix4*
5782 ARM with RDP protocol arm-*-*
5783 I960 with MON960 i960-*-coff
5784 MIPS VxWorks mips*-*-vxworks*
5785 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5786 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5788 Matra Sparclet sparclet-*-*
5792 The powerpc-eabi configuration now includes the PSIM simulator,
5793 contributed by Andrew Cagney, with assistance from Mike Meissner.
5794 PSIM is a very elaborate model of the PowerPC, including not only
5795 basic instruction set execution, but also details of execution unit
5796 performance and I/O hardware. See sim/ppc/README for more details.
5800 GDB now works with Solaris 2.5.
5802 * Windows 95/NT native
5804 GDB will now work as a native debugger on Windows 95 and Windows NT.
5805 To build it from source, you must use the "gnu-win32" environment,
5806 which uses a DLL to emulate enough of Unix to run the GNU tools.
5807 Further information, binaries, and sources are available at
5808 ftp.cygnus.com, under pub/gnu-win32.
5810 * dont-repeat command
5812 If a user-defined command includes the command `dont-repeat', then the
5813 command will not be repeated if the user just types return. This is
5814 useful if the command is time-consuming to run, so that accidental
5815 extra keystrokes don't run the same command many times.
5817 * Send break instead of ^C
5819 The standard remote protocol now includes an option to send a break
5820 rather than a ^C to the target in order to interrupt it. By default,
5821 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5823 * Remote protocol timeout
5825 The standard remote protocol includes a new variable `remotetimeout'
5826 that allows you to set the number of seconds before GDB gives up trying
5827 to read from the target. The default value is 2.
5829 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5831 By default GDB will automatically keep track of objects as they are
5832 loaded and unloaded by the dynamic linker. By using the command `set
5833 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5834 when shared library events occur, thus allowing you to set breakpoints
5835 in shared libraries which are explicitly loaded by the inferior.
5837 Note this feature does not work on hpux8. On hpux9 you must link
5838 /usr/lib/end.o into your program. This feature should work
5839 automatically on hpux10.
5841 * Irix 5.x hardware watchpoint support
5843 Irix 5 configurations now support the use of hardware watchpoints.
5845 * Mips protocol "SYN garbage limit"
5847 When debugging a Mips target using the `target mips' protocol, you
5848 may set the number of characters that GDB will ignore by setting
5849 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5850 every character. The default value is 1050.
5852 * Recording and replaying remote debug sessions
5854 If you set `remotelogfile' to the name of a file, gdb will write to it
5855 a recording of a remote debug session. This recording may then be
5856 replayed back to gdb using "gdbreplay". See gdbserver/README for
5857 details. This is useful when you have a problem with GDB while doing
5858 remote debugging; you can make a recording of the session and send it
5859 to someone else, who can then recreate the problem.
5861 * Speedups for remote debugging
5863 GDB includes speedups for downloading and stepping MIPS systems using
5864 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5865 and more efficient S-record downloading.
5867 * Memory use reductions and statistics collection
5869 GDB now uses less memory and reports statistics about memory usage.
5870 Try the `maint print statistics' command, for example.
5872 *** Changes in GDB-4.15:
5874 * Psymtabs for XCOFF
5876 The symbol reader for AIX GDB now uses partial symbol tables. This
5877 can greatly improve startup time, especially for large executables.
5879 * Remote targets use caching
5881 Remote targets now use a data cache to speed up communication with the
5882 remote side. The data cache could lead to incorrect results because
5883 it doesn't know about volatile variables, thus making it impossible to
5884 debug targets which use memory mapped I/O devices. `set remotecache
5885 off' turns the the data cache off.
5887 * Remote targets may have threads
5889 The standard remote protocol now includes support for multiple threads
5890 in the target system, using new protocol commands 'H' and 'T'. See
5891 gdb/remote.c for details.
5895 If GDB is configured with `--enable-netrom', then it will include
5896 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5897 acts as though it is a bank of ROM on the target board, but you can
5898 write into it over the network. GDB's support consists only of
5899 support for fast loading into the emulated ROM; to debug, you must use
5900 another protocol, such as standard remote protocol. The usual
5901 sequence is something like
5903 target nrom <netrom-hostname>
5905 target remote <netrom-hostname>:1235
5909 GDB now includes support for the Apple Macintosh, as a host only. It
5910 may be run as either an MPW tool or as a standalone application, and
5911 it can debug through the serial port. All the usual GDB commands are
5912 available, but to the target command, you must supply "serial" as the
5913 device type instead of "/dev/ttyXX". See mpw-README in the main
5914 directory for more information on how to build. The MPW configuration
5915 scripts */mpw-config.in support only a few targets, and only the
5916 mips-idt-ecoff target has been tested.
5920 GDB configuration now uses autoconf. This is not user-visible,
5921 but does simplify configuration and building.
5925 GDB now supports hpux10.
5927 *** Changes in GDB-4.14:
5929 * New native configurations
5931 x86 FreeBSD i[345]86-*-freebsd
5932 x86 NetBSD i[345]86-*-netbsd
5933 NS32k NetBSD ns32k-*-netbsd
5934 Sparc NetBSD sparc-*-netbsd
5938 A29K VxWorks a29k-*-vxworks
5939 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5940 CPU32 EST-300 emulator m68*-*-est*
5941 PowerPC ELF powerpc-*-elf
5944 * Alpha OSF/1 support for procfs
5946 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5947 possible to attach to running processes. As the mounting of the /proc
5948 filesystem is optional on the Alpha, GDB automatically determines
5949 the availability of /proc during startup. This can lead to problems
5950 if /proc is unmounted after GDB has been started.
5952 * Arguments to user-defined commands
5954 User commands may accept up to 10 arguments separated by whitespace.
5955 Arguments are accessed within the user command via $arg0..$arg9. A
5958 print $arg0 + $arg1 + $arg2
5960 To execute the command use:
5963 Defines the command "adder" which prints the sum of its three arguments.
5964 Note the arguments are text substitutions, so they may reference variables,
5965 use complex expressions, or even perform inferior function calls.
5967 * New `if' and `while' commands
5969 This makes it possible to write more sophisticated user-defined
5970 commands. Both commands take a single argument, which is the
5971 expression to evaluate, and must be followed by the commands to
5972 execute, one per line, if the expression is nonzero, the list being
5973 terminated by the word `end'. The `if' command list may include an
5974 `else' word, which causes the following commands to be executed only
5975 if the expression is zero.
5977 * Fortran source language mode
5979 GDB now includes partial support for Fortran 77. It will recognize
5980 Fortran programs and can evaluate a subset of Fortran expressions, but
5981 variables and functions may not be handled correctly. GDB will work
5982 with G77, but does not yet know much about symbols emitted by other
5985 * Better HPUX support
5987 Most debugging facilities now work on dynamic executables for HPPAs
5988 running hpux9 or later. You can attach to running dynamically linked
5989 processes, but by default the dynamic libraries will be read-only, so
5990 for instance you won't be able to put breakpoints in them. To change
5991 that behavior do the following before running the program:
5997 This will cause the libraries to be mapped private and read-write.
5998 To revert to the normal behavior, do this:
6004 You cannot set breakpoints or examine data in the library until after
6005 the library is loaded if the function/data symbols do not have
6008 GDB can now also read debug symbols produced by the HP C compiler on
6009 HPPAs (sorry, no C++, Fortran or 68k support).
6011 * Target byte order now dynamically selectable
6013 You can choose which byte order to use with a target system, via the
6014 commands "set endian big" and "set endian little", and you can see the
6015 current setting by using "show endian". You can also give the command
6016 "set endian auto", in which case GDB will use the byte order
6017 associated with the executable. Currently, only embedded MIPS
6018 configurations support dynamic selection of target byte order.
6020 * New DOS host serial code
6022 This version uses DPMI interrupts to handle buffered I/O, so you
6023 no longer need to run asynctsr when debugging boards connected to
6026 *** Changes in GDB-4.13:
6028 * New "complete" command
6030 This lists all the possible completions for the rest of the line, if it
6031 were to be given as a command itself. This is intended for use by emacs.
6033 * Trailing space optional in prompt
6035 "set prompt" no longer adds a space for you after the prompt you set. This
6036 allows you to set a prompt which ends in a space or one that does not.
6038 * Breakpoint hit counts
6040 "info break" now displays a count of the number of times the breakpoint
6041 has been hit. This is especially useful in conjunction with "ignore"; you
6042 can ignore a large number of breakpoint hits, look at the breakpoint info
6043 to see how many times the breakpoint was hit, then run again, ignoring one
6044 less than that number, and this will get you quickly to the last hit of
6047 * Ability to stop printing at NULL character
6049 "set print null-stop" will cause GDB to stop printing the characters of
6050 an array when the first NULL is encountered. This is useful when large
6051 arrays actually contain only short strings.
6053 * Shared library breakpoints
6055 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6056 breakpoints in shared libraries before the executable is run.
6058 * Hardware watchpoints
6060 There is a new hardware breakpoint for the watch command for sparclite
6061 targets. See gdb/sparclite/hw_breakpoint.note.
6063 Hardware watchpoints are also now supported under GNU/Linux.
6067 Annotations have been added. These are for use with graphical interfaces,
6068 and are still experimental. Currently only gdba.el uses these.
6070 * Improved Irix 5 support
6072 GDB now works properly with Irix 5.2.
6074 * Improved HPPA support
6076 GDB now works properly with the latest GCC and GAS.
6078 * New native configurations
6080 Sequent PTX4 i[34]86-sequent-ptx4
6081 HPPA running OSF/1 hppa*-*-osf*
6082 Atari TT running SVR4 m68*-*-sysv4*
6083 RS/6000 LynxOS rs6000-*-lynxos*
6087 OS/9000 i[34]86-*-os9k
6088 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6091 * Hitachi SH7000 and E7000-PC ICE support
6093 There is now support for communicating with the Hitachi E7000-PC ICE.
6094 This is available automatically when GDB is configured for the SH.
6098 As usual, a variety of small fixes and improvements, both generic
6099 and configuration-specific. See the ChangeLog for more detail.
6101 *** Changes in GDB-4.12:
6103 * Irix 5 is now supported
6107 GDB-4.12 on the HPPA has a number of changes which make it unable
6108 to debug the output from the currently released versions of GCC and
6109 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6110 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6111 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6114 *** Changes in GDB-4.11:
6116 * User visible changes:
6120 The "set remotedebug" option is now consistent between the mips remote
6121 target, remote targets using the gdb-specific protocol, UDI (AMD's
6122 debug protocol for the 29k) and the 88k bug monitor. It is now an
6123 integer specifying a debug level (normally 0 or 1, but 2 means more
6124 debugging info for the mips target).
6126 * DEC Alpha native support
6128 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6129 debug info, but GDB works fairly well with the DEC compiler and should
6130 work with a future GCC release. See the README file for a few
6131 Alpha-specific notes.
6133 * Preliminary thread implementation
6135 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6137 * LynxOS native and target support for 386
6139 This release has been hosted on LynxOS 2.2, and also can be configured
6140 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6143 * Improvements in C++ mangling/demangling.
6145 This release has much better g++ debugging, specifically in name
6146 mangling/demangling, virtual function calls, print virtual table,
6147 call methods, ...etc.
6149 *** Changes in GDB-4.10:
6151 * User visible changes:
6153 Remote debugging using the GDB-specific (`target remote') protocol now
6154 supports the `load' command. This is only useful if you have some
6155 other way of getting the stub to the target system, and you can put it
6156 somewhere in memory where it won't get clobbered by the download.
6158 Filename completion now works.
6160 When run under emacs mode, the "info line" command now causes the
6161 arrow to point to the line specified. Also, "info line" prints
6162 addresses in symbolic form (as well as hex).
6164 All vxworks based targets now support a user settable option, called
6165 vxworks-timeout. This option represents the number of seconds gdb
6166 should wait for responses to rpc's. You might want to use this if
6167 your vxworks target is, perhaps, a slow software simulator or happens
6168 to be on the far side of a thin network line.
6172 This release contains support for using a DEC alpha as a GDB host for
6173 cross debugging. Native alpha debugging is not supported yet.
6176 *** Changes in GDB-4.9:
6180 This is the first GDB release which is accompanied by a matching testsuite.
6181 The testsuite requires installation of dejagnu, which should be available
6182 via ftp from most sites that carry GNU software.
6186 'Cfront' style demangling has had its name changed to 'ARM' style, to
6187 emphasize that it was written from the specifications in the C++ Annotated
6188 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6189 disclaimers, it still generated too much confusion with users attempting to
6190 use gdb with AT&T cfront.
6194 GDB now uses a standard remote interface to a simulator library.
6195 So far, the library contains simulators for the Zilog Z8001/2, the
6196 Hitachi H8/300, H8/500 and Super-H.
6198 * New targets supported
6200 H8/300 simulator h8300-hitachi-hms or h8300hms
6201 H8/500 simulator h8500-hitachi-hms or h8500hms
6202 SH simulator sh-hitachi-hms or sh
6203 Z8000 simulator z8k-zilog-none or z8ksim
6204 IDT MIPS board over serial line mips-idt-ecoff
6206 Cross-debugging to GO32 targets is supported. It requires a custom
6207 version of the i386-stub.c module which is integrated with the
6208 GO32 memory extender.
6210 * New remote protocols
6212 MIPS remote debugging protocol.
6214 * New source languages supported
6216 This version includes preliminary support for Chill, a Pascal like language
6217 used by telecommunications companies. Chill support is also being integrated
6218 into the GNU compiler, but we don't know when it will be publically available.
6221 *** Changes in GDB-4.8:
6223 * HP Precision Architecture supported
6225 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6226 version of this support was available as a set of patches from the
6227 University of Utah. GDB does not support debugging of programs
6228 compiled with the HP compiler, because HP will not document their file
6229 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6230 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6232 Many problems in the preliminary version have been fixed.
6234 * Faster and better demangling
6236 We have improved template demangling and fixed numerous bugs in the GNU style
6237 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6238 character types (wchar_t) are now supported. Demangling of each symbol is now
6239 only done once, and is cached when the symbol table for a file is read in.
6240 This results in a small increase in memory usage for C programs, a moderate
6241 increase in memory usage for C++ programs, and a fantastic speedup in
6244 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6245 from the specifications in the Annotated Reference Manual, which AT&T's
6246 compiler does not actually implement.
6248 * G++ multiple inheritance compiler problem
6250 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6251 inheritance lattices was reworked to properly discover ambiguities. We
6252 recently found an example which causes this new algorithm to fail in a
6253 very subtle way, producing bad debug information for those classes.
6254 The file 'gcc.patch' (in this directory) can be applied to gcc to
6255 circumvent the problem. A future GCC release will contain a complete
6258 The previous G++ debug info problem (mentioned below for the gdb-4.7
6259 release) is fixed in gcc version 2.3.2.
6261 * Improved configure script
6263 The `configure' script will now attempt to guess your system type if
6264 you don't supply a host system type. The old scheme of supplying a
6265 host system triplet is preferable over using this. All the magic is
6266 done in the new `config.guess' script. Examine it for details.
6268 We have also brought our configure script much more in line with the FSF's
6269 version. It now supports the --with-xxx options. In particular,
6270 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6271 The resulting GDB will not be able to read arbitrary object file formats --
6272 only the format ``expected'' to be used on the configured target system.
6273 We hope to make this the default in a future release.
6275 * Documentation improvements
6277 There's new internal documentation on how to modify GDB, and how to
6278 produce clean changes to the code. We implore people to read it
6279 before submitting changes.
6281 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6282 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6283 `info' files are also provided. To build `info' files from scratch,
6284 you will need the latest `makeinfo' release, which will be available in
6285 a future texinfo-X.Y release.
6287 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6288 We're not sure exactly which versions have this problem, but it has
6289 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6290 or better. If that isn't possible, there is a patch in
6291 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6292 around this problem.
6296 GDB now supports array constants that can be used in expressions typed in by
6297 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6298 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6301 The new directory `gdb/sparclite' contains a program that demonstrates
6302 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6304 * New native hosts supported
6306 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6307 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6309 * New targets supported
6311 AMD 29k family via UDI a29k-amd-udi or udi29k
6313 * New file formats supported
6315 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6316 HPUX core files, and SCO 3.2v2 core files.
6320 Attaching to processes now works again; thanks for the many bug reports.
6322 We have also stomped on a bunch of core dumps caused by
6323 printf_filtered("%s") problems.
6325 We eliminated a copyright problem on the rpc and ptrace header files
6326 for VxWorks, which was discovered at the last minute during the 4.7
6327 release. You should now be able to build a VxWorks GDB.
6329 You can now interrupt gdb while an attached process is running. This
6330 will cause the attached process to stop, and give control back to GDB.
6332 We fixed problems caused by using too many file descriptors
6333 for reading symbols from object files and libraries. This was
6334 especially a problem for programs that used many (~100) shared
6337 The `step' command now only enters a subroutine if there is line number
6338 information for the subroutine. Otherwise it acts like the `next'
6339 command. Previously, `step' would enter subroutines if there was
6340 any debugging information about the routine. This avoids problems
6341 when using `cc -g1' on MIPS machines.
6343 * Internal improvements
6345 GDB's internal interfaces have been improved to make it easier to support
6346 debugging of multiple languages in the future.
6348 GDB now uses a common structure for symbol information internally.
6349 Minimal symbols (derived from linkage symbols in object files), partial
6350 symbols (from a quick scan of debug information), and full symbols
6351 contain a common subset of information, making it easier to write
6352 shared code that handles any of them.
6354 * New command line options
6356 We now accept --silent as an alias for --quiet.
6360 The memory-mapped-malloc library is now licensed under the GNU Library
6361 General Public License.
6363 *** Changes in GDB-4.7:
6365 * Host/native/target split
6367 GDB has had some major internal surgery to untangle the support for
6368 hosts and remote targets. Now, when you configure GDB for a remote
6369 target, it will no longer load in all of the support for debugging
6370 local programs on the host. When fully completed and tested, this will
6371 ensure that arbitrary host/target combinations are possible.
6373 The primary conceptual shift is to separate the non-portable code in
6374 GDB into three categories. Host specific code is required any time GDB
6375 is compiled on that host, regardless of the target. Target specific
6376 code relates to the peculiarities of the target, but can be compiled on
6377 any host. Native specific code is everything else: it can only be
6378 built when the host and target are the same system. Child process
6379 handling and core file support are two common `native' examples.
6381 GDB's use of /proc for controlling Unix child processes is now cleaner.
6382 It has been split out into a single module under the `target_ops' vector,
6383 plus two native-dependent functions for each system that uses /proc.
6385 * New hosts supported
6387 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6388 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6389 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6391 * New targets supported
6393 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6394 68030 and CPU32 m68030-*-*, m68332-*-*
6396 * New native hosts supported
6398 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6399 (386bsd is not well tested yet)
6400 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6402 * New file formats supported
6404 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6405 supports reading of `a.out.adobe' object files, which are an a.out
6406 format extended with minimal information about multiple sections.
6410 `show copying' is the same as the old `info copying'.
6411 `show warranty' is the same as `info warrantee'.
6412 These were renamed for consistency. The old commands continue to work.
6414 `info handle' is a new alias for `info signals'.
6416 You can now define pre-command hooks, which attach arbitrary command
6417 scripts to any command. The commands in the hook will be executed
6418 prior to the user's command. You can also create a hook which will be
6419 executed whenever the program stops. See gdb.texinfo.
6423 We now deal with Cfront style name mangling, and can even extract type
6424 info from mangled symbols. GDB can automatically figure out which
6425 symbol mangling style your C++ compiler uses.
6427 Calling of methods and virtual functions has been improved as well.
6431 The crash that occured when debugging Sun Ansi-C compiled binaries is
6432 fixed. This was due to mishandling of the extra N_SO stabs output
6435 We also finally got Ultrix 4.2 running in house, and fixed core file
6436 support, with help from a dozen people on the net.
6438 John M. Farrell discovered that the reason that single-stepping was so
6439 slow on all of the Mips based platforms (primarily SGI and DEC) was
6440 that we were trying to demangle and lookup a symbol used for internal
6441 purposes on every instruction that was being stepped through. Changing
6442 the name of that symbol so that it couldn't be mistaken for a C++
6443 mangled symbol sped things up a great deal.
6445 Rich Pixley sped up symbol lookups in general by getting much smarter
6446 about when C++ symbol mangling is necessary. This should make symbol
6447 completion (TAB on the command line) much faster. It's not as fast as
6448 we'd like, but it's significantly faster than gdb-4.6.
6452 A new user controllable variable 'call_scratch_address' can
6453 specify the location of a scratch area to be used when GDB
6454 calls a function in the target. This is necessary because the
6455 usual method of putting the scratch area on the stack does not work
6456 in systems that have separate instruction and data spaces.
6458 We integrated changes to support the 29k UDI (Universal Debugger
6459 Interface), but discovered at the last minute that we didn't have all
6460 of the appropriate copyright paperwork. We are working with AMD to
6461 resolve this, and hope to have it available soon.
6465 We have sped up the remote serial line protocol, especially for targets
6466 with lots of registers. It now supports a new `expedited status' ('T')
6467 message which can be used in place of the existing 'S' status message.
6468 This allows the remote stub to send only the registers that GDB
6469 needs to make a quick decision about single-stepping or conditional
6470 breakpoints, eliminating the need to fetch the entire register set for
6471 each instruction being stepped through.
6473 The GDB remote serial protocol now implements a write-through cache for
6474 registers, only re-reading the registers if the target has run.
6476 There is also a new remote serial stub for SPARC processors. You can
6477 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6478 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6479 processor with a serial port.
6483 Configure.in files have become much easier to read and modify. A new
6484 `table driven' format makes it more obvious what configurations are
6485 supported, and what files each one uses.
6489 There is a new opcodes library which will eventually contain all of the
6490 disassembly routines and opcode tables. At present, it only contains
6491 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6492 disassembler (binutils/objdump) to share these routines.
6494 The libiberty library is now copylefted under the GNU Library General
6495 Public License. This allows more liberal use, and was done so libg++
6496 can use it. This makes no difference to GDB, since the Library License
6497 grants all the rights from the General Public License.
6501 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6502 reference to the stabs symbol info used by the debugger. It is (as far
6503 as we know) the only published document on this fascinating topic. We
6504 encourage you to read it, compare it to the stabs information on your
6505 system, and send improvements on the document in general (to
6506 bug-gdb@prep.ai.mit.edu).
6508 And, of course, many bugs have been fixed.
6511 *** Changes in GDB-4.6:
6513 * Better support for C++ function names
6515 GDB now accepts as input the "demangled form" of C++ overloaded function
6516 names and member function names, and can do command completion on such names
6517 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6518 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6519 Make use of command completion, it is your friend.
6521 GDB also now accepts a variety of C++ mangled symbol formats. They are
6522 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6523 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6524 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6525 for the list of formats.
6527 * G++ symbol mangling problem
6529 Recent versions of gcc have a bug in how they emit debugging information for
6530 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6531 directory) can be applied to gcc to fix the problem. Alternatively, if you
6532 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6533 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6534 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6537 * New 'maintenance' command
6539 All of the commands related to hacking GDB internals have been moved out of
6540 the main command set, and now live behind the 'maintenance' command. This
6541 can also be abbreviated as 'mt'. The following changes were made:
6543 dump-me -> maintenance dump-me
6544 info all-breakpoints -> maintenance info breakpoints
6545 printmsyms -> maintenance print msyms
6546 printobjfiles -> maintenance print objfiles
6547 printpsyms -> maintenance print psymbols
6548 printsyms -> maintenance print symbols
6550 The following commands are new:
6552 maintenance demangle Call internal GDB demangler routine to
6553 demangle a C++ link name and prints the result.
6554 maintenance print type Print a type chain for a given symbol
6556 * Change to .gdbinit file processing
6558 We now read the $HOME/.gdbinit file before processing the argv arguments
6559 (e.g. reading symbol files or core files). This allows global parameters to
6560 be set, which will apply during the symbol reading. The ./.gdbinit is still
6561 read after argv processing.
6563 * New hosts supported
6565 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6567 GNU/Linux support i386-unknown-linux or linux
6569 We are also including code to support the HP/PA running BSD and HPUX. This
6570 is almost guaranteed not to work, as we didn't have time to test or build it
6571 for this release. We are including it so that the more adventurous (or
6572 masochistic) of you can play with it. We also had major problems with the
6573 fact that the compiler that we got from HP doesn't support the -g option.
6576 * New targets supported
6578 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6580 * More smarts about finding #include files
6582 GDB now remembers the compilation directory for all include files, and for
6583 all files from which C is generated (like yacc and lex sources). This
6584 greatly improves GDB's ability to find yacc/lex sources, and include files,
6585 especially if you are debugging your program from a directory different from
6586 the one that contains your sources.
6588 We also fixed a bug which caused difficulty with listing and setting
6589 breakpoints in include files which contain C code. (In the past, you had to
6590 try twice in order to list an include file that you hadn't looked at before.)
6592 * Interesting infernals change
6594 GDB now deals with arbitrary numbers of sections, where the symbols for each
6595 section must be relocated relative to that section's landing place in the
6596 target's address space. This work was needed to support ELF with embedded
6597 stabs used by Solaris-2.0.
6599 * Bug fixes (of course!)
6601 There have been loads of fixes for the following things:
6602 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6603 i960, stabs, DOS(GO32), procfs, etc...
6605 See the ChangeLog for details.
6607 *** Changes in GDB-4.5:
6609 * New machines supported (host and target)
6611 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6613 SGI Irix-4.x mips-sgi-irix4 or iris4
6615 * New malloc package
6617 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6618 Mmalloc is capable of handling mutiple heaps of memory. It is also
6619 capable of saving a heap to a file, and then mapping it back in later.
6620 This can be used to greatly speedup the startup of GDB by using a
6621 pre-parsed symbol table which lives in a mmalloc managed heap. For
6622 more details, please read mmalloc/mmalloc.texi.
6626 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6627 'help info proc' for details.
6629 * MIPS ecoff symbol table format
6631 The code that reads MIPS symbol table format is now supported on all hosts.
6632 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6635 * File name changes for MS-DOS
6637 Many files in the config directories have been renamed to make it easier to
6638 support GDB on MS-DOSe systems (which have very restrictive file name
6639 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6640 environment) is close to working but has some remaining problems. Note
6641 that debugging of DOS programs is not supported, due to limitations
6642 in the ``operating system'', but it can be used to host cross-debugging.
6644 * Cross byte order fixes
6646 Many fixes have been made to support cross debugging of Sparc and MIPS
6647 targets from hosts whose byte order differs.
6649 * New -mapped and -readnow options
6651 If memory-mapped files are available on your system through the 'mmap'
6652 system call, you can use the -mapped option on the `file' or
6653 `symbol-file' commands to cause GDB to write the symbols from your
6654 program into a reusable file. If the program you are debugging is
6655 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6656 Future GDB debugging sessions will notice the presence of this file,
6657 and will quickly map in symbol information from it, rather than reading
6658 the symbol table from the executable program. Using the '-mapped'
6659 option in a GDB `file' or `symbol-file' command has the same effect as
6660 starting GDB with the '-mapped' command-line option.
6662 You can cause GDB to read the entire symbol table immediately by using
6663 the '-readnow' option with any of the commands that load symbol table
6664 information (or on the GDB command line). This makes the command
6665 slower, but makes future operations faster.
6667 The -mapped and -readnow options are typically combined in order to
6668 build a `fred.syms' file that contains complete symbol information.
6669 A simple GDB invocation to do nothing but build a `.syms' file for future
6672 gdb -batch -nx -mapped -readnow programname
6674 The `.syms' file is specific to the host machine on which GDB is run.
6675 It holds an exact image of GDB's internal symbol table. It cannot be
6676 shared across multiple host platforms.
6678 * longjmp() handling
6680 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6681 siglongjmp() without losing control. This feature has not yet been ported to
6682 all systems. It currently works on many 386 platforms, all MIPS-based
6683 platforms (SGI, DECstation, etc), and Sun3/4.
6687 Preliminary work has been put in to support the new Solaris OS from Sun. At
6688 this time, it can control and debug processes, but it is not capable of
6693 As always, many many bug fixes. The major areas were with g++, and mipsread.
6694 People using the MIPS-based platforms should experience fewer mysterious
6695 crashes and trashed symbol tables.
6697 *** Changes in GDB-4.4:
6699 * New machines supported (host and target)
6701 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6703 BSD Reno on Vax vax-dec-bsd
6704 Ultrix on Vax vax-dec-ultrix
6706 * New machines supported (target)
6708 AMD 29000 embedded, using EBMON a29k-none-none
6712 GDB continues to improve its handling of C++. `References' work better.
6713 The demangler has also been improved, and now deals with symbols mangled as
6714 per the Annotated C++ Reference Guide.
6716 GDB also now handles `stabs' symbol information embedded in MIPS
6717 `ecoff' symbol tables. Since the ecoff format was not easily
6718 extensible to handle new languages such as C++, this appeared to be a
6719 good way to put C++ debugging info into MIPS binaries. This option
6720 will be supported in the GNU C compiler, version 2, when it is
6723 * New features for SVR4
6725 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6726 shared libraries. Debugging dynamically linked programs should present
6727 only minor differences from debugging statically linked programs.
6729 The `info proc' command will print out information about any process
6730 on an SVR4 system (including the one you are debugging). At the moment,
6731 it prints the address mappings of the process.
6733 If you bring up GDB on another SVR4 system, please send mail to
6734 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6736 * Better dynamic linking support in SunOS
6738 Reading symbols from shared libraries which contain debugging symbols
6739 now works properly. However, there remain issues such as automatic
6740 skipping of `transfer vector' code during function calls, which
6741 make it harder to debug code in a shared library, than to debug the
6742 same code linked statically.
6746 GDB is now using the latest `getopt' routines from the FSF. This
6747 version accepts the -- prefix for options with long names. GDB will
6748 continue to accept the old forms (-option and +option) as well.
6749 Various single letter abbreviations for options have been explicity
6750 added to the option table so that they won't get overshadowed in the
6751 future by other options that begin with the same letter.
6755 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6756 Many assorted bugs have been handled. Many more remain to be handled.
6757 See the various ChangeLog files (primarily in gdb and bfd) for details.
6760 *** Changes in GDB-4.3:
6762 * New machines supported (host and target)
6764 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6765 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6766 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6768 * Almost SCO Unix support
6770 We had hoped to support:
6771 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6772 (except for core file support), but we discovered very late in the release
6773 that it has problems with process groups that render gdb unusable. Sorry
6774 about that. I encourage people to fix it and post the fixes.
6776 * Preliminary ELF and DWARF support
6778 GDB can read ELF object files on System V Release 4, and can handle
6779 debugging records for C, in DWARF format, in ELF files. This support
6780 is preliminary. If you bring up GDB on another SVR4 system, please
6781 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6786 GDB now uses the latest `readline' library. One user-visible change
6787 is that two tabs will list possible command completions, which previously
6788 required typing M-? (meta-question mark, or ESC ?).
6792 The `stepi' bug that many of you noticed has been squashed.
6793 Many bugs in C++ have been handled. Many more remain to be handled.
6794 See the various ChangeLog files (primarily in gdb and bfd) for details.
6796 * State of the MIPS world (in case you wondered):
6798 GDB can understand the symbol tables emitted by the compilers
6799 supplied by most vendors of MIPS-based machines, including DEC. These
6800 symbol tables are in a format that essentially nobody else uses.
6802 Some versions of gcc come with an assembler post-processor called
6803 mips-tfile. This program is required if you want to do source-level
6804 debugging of gcc-compiled programs. I believe FSF does not ship
6805 mips-tfile with gcc version 1, but it will eventually come with gcc
6808 Debugging of g++ output remains a problem. g++ version 1.xx does not
6809 really support it at all. (If you're lucky, you should be able to get
6810 line numbers and stack traces to work, but no parameters or local
6811 variables.) With some work it should be possible to improve the
6814 When gcc version 2 is released, you will have somewhat better luck.
6815 However, even then you will get confusing results for inheritance and
6818 We will eventually provide full debugging of g++ output on
6819 DECstations. This will probably involve some kind of stabs-in-ecoff
6820 encapulation, but the details have not been worked out yet.
6823 *** Changes in GDB-4.2:
6825 * Improved configuration
6827 Only one copy of `configure' exists now, and it is not self-modifying.
6828 Porting BFD is simpler.
6832 The `step' and `next' commands now only stop at the first instruction
6833 of a source line. This prevents the multiple stops that used to occur
6834 in switch statements, for-loops, etc. `Step' continues to stop if a
6835 function that has debugging information is called within the line.
6839 Lots of small bugs fixed. More remain.
6841 * New host supported (not target)
6843 Intel 386 PC clone running Mach i386-none-mach
6846 *** Changes in GDB-4.1:
6848 * Multiple source language support
6850 GDB now has internal scaffolding to handle several source languages.
6851 It determines the type of each source file from its filename extension,
6852 and will switch expression parsing and number formatting to match the
6853 language of the function in the currently selected stack frame.
6854 You can also specifically set the language to be used, with
6855 `set language c' or `set language modula-2'.
6859 GDB now has preliminary support for the GNU Modula-2 compiler,
6860 currently under development at the State University of New York at
6861 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6862 continue through the fall of 1991 and into 1992.
6864 Other Modula-2 compilers are currently not supported, and attempting to
6865 debug programs compiled with them will likely result in an error as the
6866 symbol table is read. Feel free to work on it, though!
6868 There are hooks in GDB for strict type checking and range checking,
6869 in the `Modula-2 philosophy', but they do not currently work.
6873 GDB can now write to executable and core files (e.g. patch
6874 a variable's value). You must turn this switch on, specify
6875 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6876 by assigning a new value to a variable. Modifications take
6879 * Automatic SunOS shared library reading
6881 When you run your program, GDB automatically determines where its
6882 shared libraries (if any) have been loaded, and reads their symbols.
6883 The `share' command is no longer needed. This also works when
6884 examining core files.
6888 You can specify the number of lines that the `list' command shows.
6891 * New machines supported (host and target)
6893 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6894 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6895 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6897 * New hosts supported (not targets)
6899 IBM RT/PC: romp-ibm-aix or rtpc
6901 * New targets supported (not hosts)
6903 AMD 29000 embedded with COFF a29k-none-coff
6904 AMD 29000 embedded with a.out a29k-none-aout
6905 Ultracomputer remote kernel debug a29k-nyu-kern
6907 * New remote interfaces
6913 *** Changes in GDB-4.0:
6917 Wide output is wrapped at good places to make the output more readable.
6919 Gdb now supports cross-debugging from a host machine of one type to a
6920 target machine of another type. Communication with the target system
6921 is over serial lines. The ``target'' command handles connecting to the
6922 remote system; the ``load'' command will download a program into the
6923 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6924 also supports debugging of realtime processes running under VxWorks,
6925 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6926 stub on the target system.
6928 New CPUs supported include the AMD 29000 and Intel 960.
6930 GDB now reads object files and symbol tables via a ``binary file''
6931 library, which allows a single copy of GDB to debug programs of multiple
6932 object file types such as a.out and coff.
6934 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6935 refcard.dvi and refcard.ps are available to format it).
6938 * Control-Variable user interface simplified
6940 All variables that control the operation of the debugger can be set
6941 by the ``set'' command, and displayed by the ``show'' command.
6943 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6944 ``Show prompt'' produces the response:
6945 Gdb's prompt is new-gdb=>.
6947 What follows are the NEW set commands. The command ``help set'' will
6948 print a complete list of old and new set commands. ``help set FOO''
6949 will give a longer description of the variable FOO. ``show'' will show
6950 all of the variable descriptions and their current settings.
6952 confirm on/off: Enables warning questions for operations that are
6953 hard to recover from, e.g. rerunning the program while
6954 it is already running. Default is ON.
6956 editing on/off: Enables EMACS style command line editing
6957 of input. Previous lines can be recalled with
6958 control-P, the current line can be edited with control-B,
6959 you can search for commands with control-R, etc.
6962 history filename NAME: NAME is where the gdb command history
6963 will be stored. The default is .gdb_history,
6964 or the value of the environment variable
6967 history size N: The size, in commands, of the command history. The
6968 default is 256, or the value of the environment variable
6971 history save on/off: If this value is set to ON, the history file will
6972 be saved after exiting gdb. If set to OFF, the
6973 file will not be saved. The default is OFF.
6975 history expansion on/off: If this value is set to ON, then csh-like
6976 history expansion will be performed on
6977 command line input. The default is OFF.
6979 radix N: Sets the default radix for input and output. It can be set
6980 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6981 in the current radix, so "set radix 10" is always a no-op.
6983 height N: This integer value is the number of lines on a page. Default
6984 is 24, the current `stty rows'' setting, or the ``li#''
6985 setting from the termcap entry matching the environment
6988 width N: This integer value is the number of characters on a line.
6989 Default is 80, the current `stty cols'' setting, or the ``co#''
6990 setting from the termcap entry matching the environment
6993 Note: ``set screensize'' is obsolete. Use ``set height'' and
6994 ``set width'' instead.
6996 print address on/off: Print memory addresses in various command displays,
6997 such as stack traces and structure values. Gdb looks
6998 more ``symbolic'' if you turn this off; it looks more
6999 ``machine level'' with it on. Default is ON.
7001 print array on/off: Prettyprint arrays. New convenient format! Default
7004 print demangle on/off: Print C++ symbols in "source" form if on,
7007 print asm-demangle on/off: Same, for assembler level printouts
7010 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7013 * Support for Epoch Environment.
7015 The epoch environment is a version of Emacs v18 with windowing. One
7016 new command, ``inspect'', is identical to ``print'', except that if you
7017 are running in the epoch environment, the value is printed in its own
7021 * Support for Shared Libraries
7023 GDB can now debug programs and core files that use SunOS shared libraries.
7024 Symbols from a shared library cannot be referenced
7025 before the shared library has been linked with the program (this
7026 happens after you type ``run'' and before the function main() is entered).
7027 At any time after this linking (including when examining core files
7028 from dynamically linked programs), gdb reads the symbols from each
7029 shared library when you type the ``sharedlibrary'' command.
7030 It can be abbreviated ``share''.
7032 sharedlibrary REGEXP: Load shared object library symbols for files
7033 matching a unix regular expression. No argument
7034 indicates to load symbols for all shared libraries.
7036 info sharedlibrary: Status of loaded shared libraries.
7041 A watchpoint stops execution of a program whenever the value of an
7042 expression changes. Checking for this slows down execution
7043 tremendously whenever you are in the scope of the expression, but is
7044 quite useful for catching tough ``bit-spreader'' or pointer misuse
7045 problems. Some machines such as the 386 have hardware for doing this
7046 more quickly, and future versions of gdb will use this hardware.
7048 watch EXP: Set a watchpoint (breakpoint) for an expression.
7050 info watchpoints: Information about your watchpoints.
7052 delete N: Deletes watchpoint number N (same as breakpoints).
7053 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7054 enable N: Re-enables watchpoint number N (same as breakpoints).
7057 * C++ multiple inheritance
7059 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7062 * C++ exception handling
7064 Gdb now supports limited C++ exception handling. Besides the existing
7065 ability to breakpoint on an exception handler, gdb can breakpoint on
7066 the raising of an exception (before the stack is peeled back to the
7069 catch FOO: If there is a FOO exception handler in the dynamic scope,
7070 set a breakpoint to catch exceptions which may be raised there.
7071 Multiple exceptions (``catch foo bar baz'') may be caught.
7073 info catch: Lists all exceptions which may be caught in the
7074 current stack frame.
7077 * Minor command changes
7079 The command ``call func (arg, arg, ...)'' now acts like the print
7080 command, except it does not print or save a value if the function's result
7081 is void. This is similar to dbx usage.
7083 The ``up'' and ``down'' commands now always print the frame they end up
7084 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7085 frames without printing.
7087 * New directory command
7089 'dir' now adds directories to the FRONT of the source search path.
7090 The path starts off empty. Source files that contain debug information
7091 about the directory in which they were compiled can be found even
7092 with an empty path; Sun CC and GCC include this information. If GDB can't
7093 find your source file in the current directory, type "dir .".
7095 * Configuring GDB for compilation
7097 For normal use, type ``./configure host''. See README or gdb.texinfo
7100 GDB now handles cross debugging. If you are remotely debugging between
7101 two different machines, type ``./configure host -target=targ''.
7102 Host is the machine where GDB will run; targ is the machine
7103 where the program that you are debugging will run.