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 * New native configurations
46 GNU/Linux/RISC-V riscv*-*-linux*
50 GNU/Linux/RISC-V riscv*-*-linux*
52 *** Changes in GDB 8.2
54 * The 'set disassembler-options' command now supports specifying options
57 * The 'symbol-file' command now accepts an '-o' option to add a relative
58 offset to all sections.
60 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
61 a relative offset to all sections, but it allows to override the load
62 address of individual sections using '-s'.
64 * The 'add-symbol-file' command no longer requires the second argument
65 (address of the text section).
67 * The endianness used with the 'set endian auto' mode in the absence of
68 an executable selected for debugging is now the last endianness chosen
69 either by one of the 'set endian big' and 'set endian little' commands
70 or by inferring from the last executable used, rather than the startup
73 * The pager now allows a "c" response, meaning to disable the pager
74 for the rest of the current command.
76 * The commands 'info variables/functions/types' now show the source line
77 numbers of symbol definitions when available.
79 * 'info proc' now works on running processes on FreeBSD systems and core
80 files created on FreeBSD systems.
82 * C expressions can now use _Alignof, and C++ expressions can now use
89 Control display of debugging info regarding the FreeBSD native target.
91 set|show varsize-limit
92 This new setting allows the user to control the maximum size of Ada
93 objects being printed when those objects have a variable type,
94 instead of that maximum size being hardcoded to 65536 bytes.
96 set|show record btrace cpu
97 Controls the processor to be used for enabling errata workarounds for
100 maint check libthread-db
101 Run integrity checks on the current inferior's thread debugging
104 maint set check-libthread-db (on|off)
105 maint show check-libthread-db
106 Control whether to run integrity checks on inferior specific thread
107 debugging libraries as they are loaded. The default is not to
112 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
114 ** The commands attached to a breakpoint can be set by assigning to
115 the breakpoint's "commands" field.
117 ** gdb.execute can now execute multi-line gdb commands.
119 ** The new functions gdb.convenience_variable and
120 gdb.set_convenience_variable can be used to get and set the value
121 of convenience variables.
123 ** A gdb.Parameter will no longer print the "set" help text on an
124 ordinary "set"; instead by default a "set" will be silent unless
125 the get_set_string method returns a non-empty string.
129 RiscV ELF riscv*-*-elf
131 * Removed targets and native configurations
133 m88k running OpenBSD m88*-*-openbsd*
134 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
135 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
136 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
138 * Aarch64/Linux hardware watchpoints improvements
140 Hardware watchpoints on unaligned addresses are now properly
141 supported when running Linux kernel 4.10 or higher: read and access
142 watchpoints are no longer spuriously missed, and all watchpoints
143 lengths between 1 and 8 bytes are supported. On older kernels,
144 watchpoints set on unaligned addresses are no longer missed, with
145 the tradeoff that there is a possibility of false hits being
150 --enable-codesign=CERT
151 This can be used to invoke "codesign -s CERT" after building gdb.
152 This option is useful on macOS, where code signing is required for
153 gdb to work properly.
155 --disable-gdbcli has been removed
156 This is now silently accepted, but does nothing.
158 *** Changes in GDB 8.1
160 * GDB now supports dynamically creating arbitrary register groups specified
161 in XML target descriptions. This allows for finer grain grouping of
162 registers on systems with a large amount of registers.
164 * The 'ptype' command now accepts a '/o' flag, which prints the
165 offsets and sizes of fields in a struct, like the pahole(1) tool.
167 * New "--readnever" command line option instructs GDB to not read each
168 symbol file's symbolic debug information. This makes startup faster
169 but at the expense of not being able to perform symbolic debugging.
170 This option is intended for use cases where symbolic debugging will
171 not be used, e.g., when you only need to dump the debuggee's core.
173 * GDB now uses the GNU MPFR library, if available, to emulate target
174 floating-point arithmetic during expression evaluation when the target
175 uses different floating-point formats than the host. At least version
176 3.1 of GNU MPFR is required.
178 * GDB now supports access to the guarded-storage-control registers and the
179 software-based guarded-storage broadcast control registers on IBM z14.
181 * On Unix systems, GDB now supports transmitting environment variables
182 that are to be set or unset to GDBserver. These variables will
183 affect the environment to be passed to the remote inferior.
185 To inform GDB of environment variables that are to be transmitted to
186 GDBserver, use the "set environment" command. Only user set
187 environment variables are sent to GDBserver.
189 To inform GDB of environment variables that are to be unset before
190 the remote inferior is started by the GDBserver, use the "unset
191 environment" command.
193 * Completion improvements
195 ** GDB can now complete function parameters in linespecs and
196 explicit locations without quoting. When setting breakpoints,
197 quoting around functions names to help with TAB-completion is
198 generally no longer necessary. For example, this now completes
201 (gdb) b function(in[TAB]
202 (gdb) b function(int)
204 Related, GDB is no longer confused with completing functions in
205 C++ anonymous namespaces:
208 (gdb) b (anonymous namespace)::[TAB][TAB]
209 (anonymous namespace)::a_function()
210 (anonymous namespace)::b_function()
212 ** GDB now has much improved linespec and explicit locations TAB
213 completion support, that better understands what you're
214 completing and offers better suggestions. For example, GDB no
215 longer offers data symbols as possible completions when you're
216 setting a breakpoint.
218 ** GDB now TAB-completes label symbol names.
220 ** The "complete" command now mimics TAB completion accurately.
222 * New command line options (gcore)
225 Dump all memory mappings.
227 * Breakpoints on C++ functions are now set on all scopes by default
229 By default, breakpoints on functions/methods are now interpreted as
230 specifying all functions with the given name ignoring missing
231 leading scopes (namespaces and classes).
233 For example, assuming a C++ program with symbols named:
238 both commands "break func()" and "break B::func()" set a breakpoint
241 You can use the new flag "-qualified" to override this. This makes
242 GDB interpret the specified function name as a complete
243 fully-qualified name instead. For example, using the same C++
244 program, the "break -q B::func" command sets a breakpoint on
245 "B::func", only. A parameter has been added to the Python
246 gdb.Breakpoint constructor to achieve the same result when creating
247 a breakpoint from Python.
249 * Breakpoints on functions marked with C++ ABI tags
251 GDB can now set breakpoints on functions marked with C++ ABI tags
252 (e.g., [abi:cxx11]). See here for a description of ABI tags:
253 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
255 Functions with a C++11 abi tag are demangled/displayed like this:
257 function[abi:cxx11](int)
260 You can now set a breakpoint on such functions simply as if they had
263 (gdb) b function(int)
265 Or if you need to disambiguate between tags, like:
267 (gdb) b function[abi:other_tag](int)
269 Tab completion was adjusted accordingly as well.
273 ** New events gdb.new_inferior, gdb.inferior_deleted, and
274 gdb.new_thread are emitted. See the manual for further
275 description of these.
277 ** A new function, "gdb.rbreak" has been added to the Python API.
278 This function allows the setting of a large number of breakpoints
279 via a regex pattern in Python. See the manual for further details.
281 ** Python breakpoints can now accept explicit locations. See the
282 manual for a further description of this feature.
285 * New features in the GDB remote stub, GDBserver
287 ** GDBserver is now able to start inferior processes with a
288 specified initial working directory.
290 The user can set the desired working directory to be used from
291 GDB using the new "set cwd" command.
293 ** New "--selftest" command line option runs some GDBserver self
294 tests. These self tests are disabled in releases.
296 ** On Unix systems, GDBserver now does globbing expansion and variable
297 substitution in inferior command line arguments.
299 This is done by starting inferiors using a shell, like GDB does.
300 See "set startup-with-shell" in the user manual for how to disable
301 this from GDB when using "target extended-remote". When using
302 "target remote", you can disable the startup with shell by using the
303 new "--no-startup-with-shell" GDBserver command line option.
305 ** On Unix systems, GDBserver now supports receiving environment
306 variables that are to be set or unset from GDB. These variables
307 will affect the environment to be passed to the inferior.
309 * When catching an Ada exception raised with a message, GDB now prints
310 the message in the catchpoint hit notification. In GDB/MI mode, that
311 information is provided as an extra field named "exception-message"
312 in the *stopped notification.
314 * Trait objects can now be inspected When debugging Rust code. This
315 requires compiler support which will appear in Rust 1.24.
319 QEnvironmentHexEncoded
320 Inform GDBserver of an environment variable that is to be passed to
321 the inferior when starting it.
324 Inform GDBserver of an environment variable that is to be unset
325 before starting the remote inferior.
328 Inform GDBserver that the environment should be reset (i.e.,
329 user-set environment variables should be unset).
332 Indicates whether the inferior must be started with a shell or not.
335 Tell GDBserver that the inferior to be started should use a specific
338 * The "maintenance print c-tdesc" command now takes an optional
339 argument which is the file name of XML target description.
341 * The "maintenance selftest" command now takes an optional argument to
342 filter the tests to be run.
344 * The "enable", and "disable" commands now accept a range of
345 breakpoint locations, e.g. "enable 1.3-5".
350 Set and show the current working directory for the inferior.
353 Set and show compilation command used for compiling and injecting code
354 with the 'compile' commands.
356 set debug separate-debug-file
357 show debug separate-debug-file
358 Control the display of debug output about separate debug file search.
360 set dump-excluded-mappings
361 show dump-excluded-mappings
362 Control whether mappings marked with the VM_DONTDUMP flag should be
363 dumped when generating a core file.
366 List the registered selftests.
369 Start the debugged program stopping at the first instruction.
372 Control display of debugging messages related to OpenRISC targets.
374 set|show print type nested-type-limit
375 Set and show the limit of nesting level for nested types that the
376 type printer will show.
378 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
381 * Safer/improved support for debugging with no debug info
383 GDB no longer assumes functions with no debug information return
386 This means that GDB now refuses to call such functions unless you
387 tell it the function's type, by either casting the call to the
388 declared return type, or by casting the function to a function
389 pointer of the right type, and calling that:
391 (gdb) p getenv ("PATH")
392 'getenv' has unknown return type; cast the call to its declared return type
393 (gdb) p (char *) getenv ("PATH")
394 $1 = 0x7fffffffe "/usr/local/bin:/"...
395 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
396 $2 = 0x7fffffffe "/usr/local/bin:/"...
398 Similarly, GDB no longer assumes that global variables with no debug
399 info have type 'int', and refuses to print the variable's value
400 unless you tell it the variable's type:
403 'var' has unknown type; cast it to its declared type
407 * New native configurations
409 FreeBSD/aarch64 aarch64*-*-freebsd*
410 FreeBSD/arm arm*-*-freebsd*
414 FreeBSD/aarch64 aarch64*-*-freebsd*
415 FreeBSD/arm arm*-*-freebsd*
416 OpenRISC ELF or1k*-*-elf
418 * Removed targets and native configurations
420 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
422 *** Changes in GDB 8.0
424 * GDB now supports access to the PKU register on GNU/Linux. The register is
425 added by the Memory Protection Keys for Userspace feature which will be
426 available in future Intel CPUs.
428 * GDB now supports C++11 rvalue references.
432 ** New functions to start, stop and access a running btrace recording.
433 ** Rvalue references are now supported in gdb.Type.
435 * GDB now supports recording and replaying rdrand and rdseed Intel 64
438 * Building GDB and GDBserver now requires a C++11 compiler.
440 For example, GCC 4.8 or later.
442 It is no longer possible to build GDB or GDBserver with a C
443 compiler. The --disable-build-with-cxx configure option has been
446 * Building GDB and GDBserver now requires GNU make >= 3.81.
448 It is no longer supported to build GDB or GDBserver with another
449 implementation of the make program or an earlier version of GNU make.
451 * Native debugging on MS-Windows supports command-line redirection
453 Command-line arguments used for starting programs on MS-Windows can
454 now include redirection symbols supported by native Windows shells,
455 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
456 as "run", "start", and "set args", as well as the corresponding MI
459 * Support for thread names on MS-Windows.
461 GDB now catches and handles the special exception that programs
462 running on MS-Windows use to assign names to threads in the
465 * Support for Java programs compiled with gcj has been removed.
467 * User commands now accept an unlimited number of arguments.
468 Previously, only up to 10 was accepted.
470 * The "eval" command now expands user-defined command arguments.
472 This makes it easier to process a variable number of arguments:
477 eval "print $arg%d", $i
482 * Target descriptions can now describe registers for sparc32 and sparc64.
484 * GDB now supports DWARF version 5 (debug information format).
485 Its .debug_names index is not yet supported.
487 * New native configurations
489 FreeBSD/mips mips*-*-freebsd
493 Synopsys ARC arc*-*-elf32
494 FreeBSD/mips mips*-*-freebsd
496 * Removed targets and native configurations
498 Alpha running FreeBSD alpha*-*-freebsd*
499 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
504 Erases all the flash memory regions reported by the target.
506 maint print arc arc-instruction address
507 Print internal disassembler information about instruction at a given address.
511 set disassembler-options
512 show disassembler-options
513 Controls the passing of target specific information to the disassembler.
514 If it is necessary to specify more than one disassembler option then
515 multiple options can be placed together into a comma separated list.
516 The default value is the empty string. Currently, the only supported
517 targets are ARM, PowerPC and S/390.
522 Erases all the flash memory regions reported by the target. This is
523 equivalent to the CLI command flash-erase.
525 -file-list-shared-libraries
526 List the shared libraries in the program. This is
527 equivalent to the CLI command "info shared".
530 Catchpoints stopping the program when Ada exceptions are
531 handled. This is equivalent to the CLI command "catch handlers".
533 *** Changes in GDB 7.12
535 * GDB and GDBserver now build with a C++ compiler by default.
537 The --enable-build-with-cxx configure option is now enabled by
538 default. One must now explicitly configure with
539 --disable-build-with-cxx in order to build with a C compiler. This
540 option will be removed in a future release.
542 * GDBserver now supports recording btrace without maintaining an active
545 * GDB now supports a negative repeat count in the 'x' command to examine
546 memory backward from the given address. For example:
549 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
550 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
551 (gdb) x/-5i 0x0000000000400580
552 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
553 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
554 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
555 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
556 0x40057b <main(int, char**)+25>:
557 callq 0x400536 <Func1(int, char const*)>
559 * Fortran: Support structures with fields of dynamic types and
560 arrays of dynamic types.
562 * The symbol dumping maintenance commands have new syntax.
563 maint print symbols [-pc address] [--] [filename]
564 maint print symbols [-objfile objfile] [-source source] [--] [filename]
565 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
566 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
567 maint print msymbols [-objfile objfile] [--] [filename]
569 * GDB now supports multibit bitfields and enums in target register
572 * New Python-based convenience function $_as_string(val), which returns
573 the textual representation of a value. This function is especially
574 useful to obtain the text label of an enum value.
576 * Intel MPX bound violation handling.
578 Segmentation faults caused by a Intel MPX boundary violation
579 now display the kind of violation (upper or lower), the memory
580 address accessed and the memory bounds, along with the usual
581 signal received and code location.
585 Program received signal SIGSEGV, Segmentation fault
586 Upper bound violation while accessing address 0x7fffffffc3b3
587 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
588 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
590 * Rust language support.
591 GDB now supports debugging programs written in the Rust programming
592 language. See https://www.rust-lang.org/ for more information about
595 * Support for running interpreters on specified input/output devices
597 GDB now supports a new mechanism that allows frontends to provide
598 fully featured GDB console views, as a better alternative to
599 building such views on top of the "-interpreter-exec console"
600 command. See the new "new-ui" command below. With that command,
601 frontends can now start GDB in the traditional command-line mode
602 running in an embedded terminal emulator widget, and create a
603 separate MI interpreter running on a specified i/o device. In this
604 way, GDB handles line editing, history, tab completion, etc. in the
605 console all by itself, and the GUI uses the separate MI interpreter
606 for its own control and synchronization, invisible to the command
609 * The "catch syscall" command catches groups of related syscalls.
611 The "catch syscall" command now supports catching a group of related
612 syscalls using the 'group:' or 'g:' prefix.
617 skip -gfile file-glob-pattern
618 skip -function function
619 skip -rfunction regular-expression
620 A generalized form of the skip command, with new support for
621 glob-style file names and regular expressions for function names.
622 Additionally, a file spec and a function spec may now be combined.
624 maint info line-table REGEXP
625 Display the contents of GDB's internal line table data struture.
628 Run any GDB unit tests that were compiled in.
631 Start a new user interface instance running INTERP as interpreter,
632 using the TTY file for input/output.
636 ** gdb.Breakpoint objects have a new attribute "pending", which
637 indicates whether the breakpoint is pending.
638 ** Three new breakpoint-related events have been added:
639 gdb.breakpoint_created, gdb.breakpoint_modified, and
640 gdb.breakpoint_deleted.
643 Signal ("set") the given MS-Windows event object. This is used in
644 conjunction with the Windows JIT debugging (AeDebug) support, where
645 the OS suspends a crashing process until a debugger can attach to
646 it. Resuming the crashing process, in order to debug it, is done by
649 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
650 was added in GDBserver, including JIT compiling fast tracepoint's
651 conditional expression bytecode into native code.
653 * Support for various remote target protocols and ROM monitors has
656 target m32rsdi Remote M32R debugging over SDI
657 target mips MIPS remote debugging protocol
658 target pmon PMON ROM monitor
659 target ddb NEC's DDB variant of PMON for Vr4300
660 target rockhopper NEC RockHopper variant of PMON
661 target lsi LSI variant of PMO
663 * Support for tracepoints and fast tracepoints on powerpc-linux,
664 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
665 including JIT compiling fast tracepoint's conditional expression
666 bytecode into native code.
668 * MI async record =record-started now includes the method and format used for
669 recording. For example:
671 =record-started,thread-group="i1",method="btrace",format="bts"
673 * MI async record =thread-selected now includes the frame field. For example:
675 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
679 Andes NDS32 nds32*-*-elf
681 *** Changes in GDB 7.11
683 * GDB now supports debugging kernel-based threads on FreeBSD.
685 * Per-inferior thread numbers
687 Thread numbers are now per inferior instead of global. If you're
688 debugging multiple inferiors, GDB displays thread IDs using a
689 qualified INF_NUM.THR_NUM form. For example:
693 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
694 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
695 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
696 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
698 As consequence, thread numbers as visible in the $_thread
699 convenience variable and in Python's InferiorThread.num attribute
700 are no longer unique between inferiors.
702 GDB now maintains a second thread ID per thread, referred to as the
703 global thread ID, which is the new equivalent of thread numbers in
704 previous releases. See also $_gthread below.
706 For backwards compatibility, MI's thread IDs always refer to global
709 * Commands that accept thread IDs now accept the qualified
710 INF_NUM.THR_NUM form as well. For example:
713 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
716 * In commands that accept a list of thread IDs, you can now refer to
717 all threads of an inferior using a star wildcard. GDB accepts
718 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
719 refer to all threads of the current inferior. For example, "info
722 * You can use "info threads -gid" to display the global thread ID of
725 * The new convenience variable $_gthread holds the global number of
728 * The new convenience variable $_inferior holds the number of the
731 * GDB now displays the ID and name of the thread that hit a breakpoint
732 or received a signal, if your program is multi-threaded. For
735 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
736 Thread 1 "main" received signal SIGINT, Interrupt.
738 * Record btrace now supports non-stop mode.
740 * Support for tracepoints on aarch64-linux was added in GDBserver.
742 * The 'record instruction-history' command now indicates speculative execution
743 when using the Intel Processor Trace recording format.
745 * GDB now allows users to specify explicit locations, bypassing
746 the linespec parser. This feature is also available to GDB/MI
749 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
750 GDB now is able to debug both AArch64 applications and ARM applications
753 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
754 including JIT compiling fast tracepoint's conditional expression bytecode
757 * GDB now supports displaced stepping on AArch64 GNU/Linux.
759 * "info threads", "info inferiors", "info display", "info checkpoints"
760 and "maint info program-spaces" now list the corresponding items in
761 ascending ID order, for consistency with all other "info" commands.
763 * In Ada, the overloads selection menu has been enhanced to display the
764 parameter types and the return types for the matching overloaded subprograms.
768 maint set target-non-stop (on|off|auto)
769 maint show target-non-stop
770 Control whether GDB targets always operate in non-stop mode even if
771 "set non-stop" is "off". The default is "auto", meaning non-stop
772 mode is enabled if supported by the target.
774 maint set bfd-sharing
775 maint show bfd-sharing
776 Control the reuse of bfd objects.
780 Control display of debugging info regarding bfd caching.
784 Control display of debugging info regarding FreeBSD threads.
786 set remote multiprocess-extensions-packet
787 show remote multiprocess-extensions-packet
788 Set/show the use of the remote protocol multiprocess extensions.
790 set remote thread-events
791 show remote thread-events
792 Set/show the use of thread create/exit events.
794 set ada print-signatures on|off
795 show ada print-signatures"
796 Control whether parameter types and return types are displayed in overloads
797 selection menus. It is activaled (@code{on}) by default.
801 Controls the maximum size of memory, in bytes, that GDB will
802 allocate for value contents. Prevents incorrect programs from
803 causing GDB to allocate overly large buffers. Default is 64k.
805 * The "disassemble" command accepts a new modifier: /s.
806 It prints mixed source+disassembly like /m with two differences:
807 - disassembled instructions are now printed in program order, and
808 - and source for all relevant files is now printed.
809 The "/m" option is now considered deprecated: its "source-centric"
810 output hasn't proved useful in practice.
812 * The "record instruction-history" command accepts a new modifier: /s.
813 It behaves exactly like /m and prints mixed source+disassembly.
815 * The "set scheduler-locking" command supports a new mode "replay".
816 It behaves like "off" in record mode and like "on" in replay mode.
818 * Support for various ROM monitors has been removed:
820 target dbug dBUG ROM monitor for Motorola ColdFire
821 target picobug Motorola picobug monitor
822 target dink32 DINK32 ROM monitor for PowerPC
823 target m32r Renesas M32R/D ROM monitor
824 target mon2000 mon2000 ROM monitor
825 target ppcbug PPCBUG ROM monitor for PowerPC
827 * Support for reading/writing memory and extracting values on architectures
828 whose memory is addressable in units of any integral multiple of 8 bits.
831 Allows to break when an Ada exception is handled.
836 Indicates that an exec system call was executed.
838 exec-events feature in qSupported
839 The qSupported packet allows GDB to request support for exec
840 events using the new 'gdbfeature' exec-event, and the qSupported
841 response can contain the corresponding 'stubfeature'. Set and
842 show commands can be used to display whether these features are enabled.
845 Equivalent to interrupting with the ^C character, but works in
848 thread created stop reason (T05 create:...)
849 Indicates that the thread was just created and is stopped at entry.
851 thread exit stop reply (w exitcode;tid)
852 Indicates that the thread has terminated.
855 Enables/disables thread create and exit event reporting. For
856 example, this is used in non-stop mode when GDB stops a set of
857 threads and synchronously waits for the their corresponding stop
858 replies. Without exit events, if one of the threads exits, GDB
859 would hang forever not knowing that it should no longer expect a
860 stop for that same thread.
863 Indicates that there are no resumed threads left in the target (all
864 threads are stopped). The remote stub reports support for this stop
865 reply to GDB's qSupported query.
868 Enables/disables catching syscalls from the inferior process.
869 The remote stub reports support for this packet to GDB's qSupported query.
871 syscall_entry stop reason
872 Indicates that a syscall was just called.
874 syscall_return stop reason
875 Indicates that a syscall just returned.
877 * Extended-remote exec events
879 ** GDB now has support for exec events on extended-remote Linux targets.
880 For such targets with Linux kernels 2.5.46 and later, this enables
881 follow-exec-mode and exec catchpoints.
883 set remote exec-event-feature-packet
884 show remote exec-event-feature-packet
885 Set/show the use of the remote exec event feature.
887 * Thread names in remote protocol
889 The reply to qXfer:threads:read may now include a name attribute for each
892 * Target remote mode fork and exec events
894 ** GDB now has support for fork and exec events on target remote mode
895 Linux targets. For such targets with Linux kernels 2.5.46 and later,
896 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
897 fork and exec catchpoints.
899 * Remote syscall events
901 ** GDB now has support for catch syscall on remote Linux targets,
902 currently enabled on x86/x86_64 architectures.
904 set remote catch-syscall-packet
905 show remote catch-syscall-packet
906 Set/show the use of the remote catch syscall feature.
910 ** The -var-set-format command now accepts the zero-hexadecimal
911 format. It outputs data in hexadecimal format with zero-padding on the
916 ** gdb.InferiorThread objects have a new attribute "global_num",
917 which refers to the thread's global thread ID. The existing
918 "num" attribute now refers to the thread's per-inferior number.
919 See "Per-inferior thread numbers" above.
920 ** gdb.InferiorThread objects have a new attribute "inferior", which
921 is the Inferior object the thread belongs to.
923 *** Changes in GDB 7.10
925 * Support for process record-replay and reverse debugging on aarch64*-linux*
926 targets has been added. GDB now supports recording of A64 instruction set
927 including advance SIMD instructions.
929 * Support for Sun's version of the "stabs" debug file format has been removed.
931 * GDB now honors the content of the file /proc/PID/coredump_filter
932 (PID is the process ID) on GNU/Linux systems. This file can be used
933 to specify the types of memory mappings that will be included in a
934 corefile. For more information, please refer to the manual page of
935 "core(5)". GDB also has a new command: "set use-coredump-filter
936 on|off". It allows to set whether GDB will read the content of the
937 /proc/PID/coredump_filter file when generating a corefile.
939 * The "info os" command on GNU/Linux can now display information on
941 "info os cpus" Listing of all cpus/cores on the system
943 * GDB has two new commands: "set serial parity odd|even|none" and
944 "show serial parity". These allows to set or show parity for the
947 * The "info source" command now displays the producer string if it was
948 present in the debug info. This typically includes the compiler version
949 and may include things like its command line arguments.
951 * The "info dll", an alias of the "info sharedlibrary" command,
952 is now available on all platforms.
954 * Directory names supplied to the "set sysroot" commands may be
955 prefixed with "target:" to tell GDB to access shared libraries from
956 the target system, be it local or remote. This replaces the prefix
957 "remote:". The default sysroot has been changed from "" to
958 "target:". "remote:" is automatically converted to "target:" for
959 backward compatibility.
961 * The system root specified by "set sysroot" will be prepended to the
962 filename of the main executable (if reported to GDB as absolute by
963 the operating system) when starting processes remotely, and when
964 attaching to already-running local or remote processes.
966 * GDB now supports automatic location and retrieval of executable
967 files from remote targets. Remote debugging can now be initiated
968 using only a "target remote" or "target extended-remote" command
969 (no "set sysroot" or "file" commands are required). See "New remote
972 * The "dump" command now supports verilog hex format.
974 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
976 * On GNU/Linux, GDB and gdbserver are now able to access executable
977 and shared library files without a "set sysroot" command when
978 attaching to processes running in different mount namespaces from
979 the debugger. This makes it possible to attach to processes in
980 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
981 See "New remote packets" below.
983 * The "tui reg" command now provides completion for all of the
984 available register groups, including target specific groups.
986 * The HISTSIZE environment variable is no longer read when determining
987 the size of GDB's command history. GDB now instead reads the dedicated
988 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
989 disables truncation of command history. Non-numeric values of GDBHISTSIZE
994 ** Memory ports can now be unbuffered.
998 ** gdb.Objfile objects have a new attribute "username",
999 which is the name of the objfile as specified by the user,
1000 without, for example, resolving symlinks.
1001 ** You can now write frame unwinders in Python.
1002 ** gdb.Type objects have a new method "optimized_out",
1003 returning optimized out gdb.Value instance of this type.
1004 ** gdb.Value objects have new methods "reference_value" and
1005 "const_value" which return a reference to the value and a
1006 "const" version of the value respectively.
1010 maint print symbol-cache
1011 Print the contents of the symbol cache.
1013 maint print symbol-cache-statistics
1014 Print statistics of symbol cache usage.
1016 maint flush-symbol-cache
1017 Flush the contents of the symbol cache.
1021 Start branch trace recording using Branch Trace Store (BTS) format.
1024 Evaluate expression by using the compiler and print result.
1028 Explicit commands for enabling and disabling tui mode.
1031 set mpx bound on i386 and amd64
1032 Support for bound table investigation on Intel MPX enabled applications.
1036 Start branch trace recording using Intel Processor Trace format.
1039 Print information about branch tracing internals.
1041 maint btrace packet-history
1042 Print the raw branch tracing data.
1044 maint btrace clear-packet-history
1045 Discard the stored raw branch tracing data.
1048 Discard all branch tracing data. It will be fetched and processed
1049 anew by the next "record" command.
1054 Renamed from "set debug dwarf2-die".
1055 show debug dwarf-die
1056 Renamed from "show debug dwarf2-die".
1058 set debug dwarf-read
1059 Renamed from "set debug dwarf2-read".
1060 show debug dwarf-read
1061 Renamed from "show debug dwarf2-read".
1063 maint set dwarf always-disassemble
1064 Renamed from "maint set dwarf2 always-disassemble".
1065 maint show dwarf always-disassemble
1066 Renamed from "maint show dwarf2 always-disassemble".
1068 maint set dwarf max-cache-age
1069 Renamed from "maint set dwarf2 max-cache-age".
1070 maint show dwarf max-cache-age
1071 Renamed from "maint show dwarf2 max-cache-age".
1073 set debug dwarf-line
1074 show debug dwarf-line
1075 Control display of debugging info regarding DWARF line processing.
1078 show max-completions
1079 Set the maximum number of candidates to be considered during
1080 completion. The default value is 200. This limit allows GDB
1081 to avoid generating large completion lists, the computation of
1082 which can cause the debugger to become temporarily unresponsive.
1084 set history remove-duplicates
1085 show history remove-duplicates
1086 Control the removal of duplicate history entries.
1088 maint set symbol-cache-size
1089 maint show symbol-cache-size
1090 Control the size of the symbol cache.
1092 set|show record btrace bts buffer-size
1093 Set and show the size of the ring buffer used for branch tracing in
1095 The obtained size may differ from the requested size. Use "info
1096 record" to see the obtained buffer size.
1098 set debug linux-namespaces
1099 show debug linux-namespaces
1100 Control display of debugging info regarding Linux namespaces.
1102 set|show record btrace pt buffer-size
1103 Set and show the size of the ring buffer used for branch tracing in
1104 Intel Processor Trace format.
1105 The obtained size may differ from the requested size. Use "info
1106 record" to see the obtained buffer size.
1108 maint set|show btrace pt skip-pad
1109 Set and show whether PAD packets are skipped when computing the
1112 * The command 'thread apply all' can now support new option '-ascending'
1113 to call its specified command for all threads in ascending order.
1115 * Python/Guile scripting
1117 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1118 special section named `.debug_gdb_scripts'.
1120 * New remote packets
1122 qXfer:btrace-conf:read
1123 Return the branch trace configuration for the current thread.
1125 Qbtrace-conf:bts:size
1126 Set the requested ring buffer size for branch tracing in BTS format.
1129 Enable Intel Procesor Trace-based branch tracing for the current
1130 process. The remote stub reports support for this packet to GDB's
1133 Qbtrace-conf:pt:size
1134 Set the requested ring buffer size for branch tracing in Intel Processor
1138 Indicates a memory breakpoint instruction was executed, irrespective
1139 of whether it was GDB that planted the breakpoint or the breakpoint
1140 is hardcoded in the program. This is required for correct non-stop
1144 Indicates the target stopped for a hardware breakpoint. This is
1145 required for correct non-stop mode operation.
1148 Return information about files on the remote system.
1150 qXfer:exec-file:read
1151 Return the full absolute name of the file that was executed to
1152 create a process running on the remote system.
1155 Select the filesystem on which vFile: operations with filename
1156 arguments will operate. This is required for GDB to be able to
1157 access files on remote targets where the remote stub does not
1158 share a common filesystem with the inferior(s).
1161 Indicates that a fork system call was executed.
1164 Indicates that a vfork system call was executed.
1166 vforkdone stop reason
1167 Indicates that a vfork child of the specified process has executed
1168 an exec or exit, allowing the vfork parent to resume execution.
1170 fork-events and vfork-events features in qSupported
1171 The qSupported packet allows GDB to request support for fork and
1172 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1173 and the qSupported response can contain the corresponding
1174 'stubfeatures'. Set and show commands can be used to display
1175 whether these features are enabled.
1177 * Extended-remote fork events
1179 ** GDB now has support for fork events on extended-remote Linux
1180 targets. For targets with Linux kernels 2.5.60 and later, this
1181 enables follow-fork-mode and detach-on-fork for both fork and
1182 vfork, as well as fork and vfork catchpoints.
1184 * The info record command now shows the recording format and the
1185 branch tracing configuration for the current thread when using
1186 the btrace record target.
1187 For the BTS format, it shows the ring buffer size.
1189 * GDB now has support for DTrace USDT (Userland Static Defined
1190 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1192 * GDB now supports access to vector registers on S/390 GNU/Linux
1195 * Removed command line options
1197 -xdb HP-UX XDB compatibility mode.
1199 * Removed targets and native configurations
1201 HP/PA running HP-UX hppa*-*-hpux*
1202 Itanium running HP-UX ia64-*-hpux*
1204 * New configure options
1207 This configure option allows the user to build GDB with support for
1208 Intel Processor Trace (default: auto). This requires libipt.
1210 --with-libipt-prefix=PATH
1211 Specify the path to the version of libipt that GDB should use.
1212 $PATH/include should contain the intel-pt.h header and
1213 $PATH/lib should contain the libipt.so library.
1215 *** Changes in GDB 7.9.1
1219 ** Xmethods can now specify a result type.
1221 *** Changes in GDB 7.9
1223 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1227 ** You can now access frame registers from Python scripts.
1228 ** New attribute 'producer' for gdb.Symtab objects.
1229 ** gdb.Objfile objects have a new attribute "progspace",
1230 which is the gdb.Progspace object of the containing program space.
1231 ** gdb.Objfile objects have a new attribute "owner".
1232 ** gdb.Objfile objects have a new attribute "build_id",
1233 which is the build ID generated when the file was built.
1234 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1235 ** A new event "gdb.clear_objfiles" has been added, triggered when
1236 selecting a new file to debug.
1237 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1238 ** New function gdb.lookup_objfile.
1240 New events which are triggered when GDB modifies the state of the
1243 ** gdb.events.inferior_call_pre: Function call is about to be made.
1244 ** gdb.events.inferior_call_post: Function call has just been made.
1245 ** gdb.events.memory_changed: A memory location has been altered.
1246 ** gdb.events.register_changed: A register has been altered.
1248 * New Python-based convenience functions:
1250 ** $_caller_is(name [, number_of_frames])
1251 ** $_caller_matches(regexp [, number_of_frames])
1252 ** $_any_caller_is(name [, number_of_frames])
1253 ** $_any_caller_matches(regexp [, number_of_frames])
1255 * GDB now supports the compilation and injection of source code into
1256 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1257 to compile the source code to object code, and if successful, inject
1258 and execute that code within the current context of the inferior.
1259 Currently the C language is supported. The commands used to
1260 interface with this new feature are:
1262 compile code [-raw|-r] [--] [source code]
1263 compile file [-raw|-r] filename
1267 demangle [-l language] [--] name
1268 Demangle "name" in the specified language, or the current language
1269 if elided. This command is renamed from the "maint demangle" command.
1270 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1271 as "maint demangler-warning".
1273 queue-signal signal-name-or-number
1274 Queue a signal to be delivered to the thread when it is resumed.
1276 add-auto-load-scripts-directory directory
1277 Add entries to the list of directories from which to load auto-loaded
1280 maint print user-registers
1281 List all currently available "user" registers.
1283 compile code [-r|-raw] [--] [source code]
1284 Compile, inject, and execute in the inferior the executable object
1285 code produced by compiling the provided source code.
1287 compile file [-r|-raw] filename
1288 Compile and inject into the inferior the executable object code
1289 produced by compiling the source code stored in the filename
1292 * On resume, GDB now always passes the signal the program had stopped
1293 for to the thread the signal was sent to, even if the user changed
1294 threads before resuming. Previously GDB would often (but not
1295 always) deliver the signal to the thread that happens to be current
1298 * Conversely, the "signal" command now consistently delivers the
1299 requested signal to the current thread. GDB now asks for
1300 confirmation if the program had stopped for a signal and the user
1301 switched threads meanwhile.
1303 * "breakpoint always-inserted" modes "off" and "auto" merged.
1305 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1306 won't remove breakpoints from the target until all threads stop,
1307 even in non-stop mode. The "auto" mode has been removed, and "off"
1308 is now the default mode.
1312 set debug symbol-lookup
1313 show debug symbol-lookup
1314 Control display of debugging info regarding symbol lookup.
1318 ** The -list-thread-groups command outputs an exit-code field for
1319 inferiors that have exited.
1323 MIPS SDE mips*-sde*-elf*
1327 Support for these obsolete configurations has been removed.
1329 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1330 SGI Irix-5.x mips-*-irix5*
1331 SGI Irix-6.x mips-*-irix6*
1332 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1333 VAX running Ultrix vax-*-ultrix*
1335 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1336 and "assf"), have been removed. Use the "sharedlibrary" command, or
1337 its alias "share", instead.
1339 *** Changes in GDB 7.8
1341 * New command line options
1344 This is an alias for the --data-directory option.
1346 * GDB supports printing and modifying of variable length automatic arrays
1347 as specified in ISO C99.
1349 * The ARM simulator now supports instruction level tracing
1350 with or without disassembly.
1354 GDB now has support for scripting using Guile. Whether this is
1355 available is determined at configure time.
1356 Guile version 2.0 or greater is required.
1357 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1359 * New commands (for set/show, see "New options" below)
1363 Invoke CODE by passing it to the Guile interpreter.
1367 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1369 info auto-load guile-scripts [regexp]
1370 Print the list of automatically loaded Guile scripts.
1372 * The source command is now capable of sourcing Guile scripts.
1373 This feature is dependent on the debugger being built with Guile support.
1377 set print symbol-loading (off|brief|full)
1378 show print symbol-loading
1379 Control whether to print informational messages when loading symbol
1380 information for a file. The default is "full", but when debugging
1381 programs with large numbers of shared libraries the amount of output
1382 becomes less useful.
1384 set guile print-stack (none|message|full)
1385 show guile print-stack
1386 Show a stack trace when an error is encountered in a Guile script.
1388 set auto-load guile-scripts (on|off)
1389 show auto-load guile-scripts
1390 Control auto-loading of Guile script files.
1392 maint ada set ignore-descriptive-types (on|off)
1393 maint ada show ignore-descriptive-types
1394 Control whether the debugger should ignore descriptive types in Ada
1395 programs. The default is not to ignore the descriptive types. See
1396 the user manual for more details on descriptive types and the intended
1397 usage of this option.
1399 set auto-connect-native-target
1401 Control whether GDB is allowed to automatically connect to the
1402 native target for the run, attach, etc. commands when not connected
1403 to any target yet. See also "target native" below.
1405 set record btrace replay-memory-access (read-only|read-write)
1406 show record btrace replay-memory-access
1407 Control what memory accesses are allowed during replay.
1409 maint set target-async (on|off)
1410 maint show target-async
1411 This controls whether GDB targets operate in synchronous or
1412 asynchronous mode. Normally the default is asynchronous, if it is
1413 available; but this can be changed to more easily debug problems
1414 occurring only in synchronous mode.
1416 set mi-async (on|off)
1418 Control whether MI asynchronous mode is preferred. This supersedes
1419 "set target-async" of previous GDB versions.
1421 * "set target-async" is deprecated as a CLI option and is now an alias
1422 for "set mi-async" (only puts MI into async mode).
1424 * Background execution commands (e.g., "c&", "s&", etc.) are now
1425 possible ``out of the box'' if the target supports them. Previously
1426 the user would need to explicitly enable the possibility with the
1427 "set target-async on" command.
1429 * New features in the GDB remote stub, GDBserver
1431 ** New option --debug-format=option1[,option2,...] allows one to add
1432 additional text to each output. At present only timestamps
1433 are supported: --debug-format=timestamps.
1434 Timestamps can also be turned on with the
1435 "monitor set debug-format timestamps" command from GDB.
1437 * The 'record instruction-history' command now starts counting instructions
1438 at one. This also affects the instruction ranges reported by the
1439 'record function-call-history' command when given the /i modifier.
1441 * The command 'record function-call-history' supports a new modifier '/c' to
1442 indent the function names based on their call stack depth.
1443 The fields for the '/i' and '/l' modifier have been reordered.
1444 The source line range is now prefixed with 'at'.
1445 The instruction range is now prefixed with 'inst'.
1446 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1447 "record instruction-history" and "list" commands.
1449 * The ranges given as arguments to the 'record function-call-history' and
1450 'record instruction-history' commands are now inclusive.
1452 * The btrace record target now supports the 'record goto' command.
1453 For locations inside the execution trace, the back trace is computed
1454 based on the information stored in the execution trace.
1456 * The btrace record target supports limited reverse execution and replay.
1457 The target does not record data and therefore does not allow reading
1458 memory or registers.
1460 * The "catch syscall" command now works on s390*-linux* targets.
1462 * The "compare-sections" command is no longer specific to target
1463 remote. It now works with all targets.
1465 * All native targets are now consistently called "native".
1466 Consequently, the "target child", "target GNU", "target djgpp",
1467 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1468 commands have been replaced with "target native". The QNX/NTO port
1469 leaves the "procfs" target in place and adds a "native" target for
1470 consistency with other ports. The impact on users should be minimal
1471 as these commands previously either throwed an error, or were
1472 no-ops. The target's name is visible in the output of the following
1473 commands: "help target", "info target", "info files", "maint print
1476 * The "target native" command now connects to the native target. This
1477 can be used to launch native programs even when "set
1478 auto-connect-native-target" is set to off.
1480 * GDB now supports access to Intel MPX registers on GNU/Linux.
1482 * Support for Intel AVX-512 registers on GNU/Linux.
1483 Support displaying and modifying Intel AVX-512 registers
1484 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1486 * New remote packets
1488 qXfer:btrace:read's annex
1489 The qXfer:btrace:read packet supports a new annex 'delta' to read
1490 branch trace incrementally.
1494 ** Valid Python operations on gdb.Value objects representing
1495 structs/classes invoke the corresponding overloaded operators if
1497 ** New `Xmethods' feature in the Python API. Xmethods are
1498 additional methods or replacements for existing methods of a C++
1499 class. This feature is useful for those cases where a method
1500 defined in C++ source code could be inlined or optimized out by
1501 the compiler, making it unavailable to GDB.
1504 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1506 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1507 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1508 its alias "share", instead.
1510 * The commands "set remotebaud" and "show remotebaud" are no longer
1511 supported. Use "set serial baud" and "show serial baud" (respectively)
1516 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1517 target-async". The latter is left as a deprecated alias of the
1518 former for backward compatibility. If the target supports it,
1519 CLI background execution commands are now always possible by
1520 default, independently of whether the frontend stated a
1521 preference for asynchronous execution with "-gdb-set mi-async".
1522 Previously "-gdb-set target-async off" affected both MI execution
1523 commands and CLI execution commands.
1525 *** Changes in GDB 7.7
1527 * Improved support for process record-replay and reverse debugging on
1528 arm*-linux* targets. Support for thumb32 and syscall instruction
1529 recording has been added.
1531 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1533 * GDB now supports Fission DWP file format version 2.
1534 http://gcc.gnu.org/wiki/DebugFission
1536 * New convenience function "$_isvoid", to check whether an expression
1537 is void. A void expression is an expression where the type of the
1538 result is "void". For example, some convenience variables may be
1539 "void" when evaluated (e.g., "$_exitcode" before the execution of
1540 the program being debugged; or an undefined convenience variable).
1541 Another example, when calling a function whose return type is
1544 * The "maintenance print objfiles" command now takes an optional regexp.
1546 * The "catch syscall" command now works on arm*-linux* targets.
1548 * GDB now consistently shows "<not saved>" when printing values of
1549 registers the debug info indicates have not been saved in the frame
1550 and there's nowhere to retrieve them from
1551 (callee-saved/call-clobbered registers):
1556 (gdb) info registers rax
1559 Before, the former would print "<optimized out>", and the latter
1560 "*value not available*".
1562 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1567 ** Frame filters and frame decorators have been added.
1568 ** Temporary breakpoints are now supported.
1569 ** Line tables representation has been added.
1570 ** New attribute 'parent_type' for gdb.Field objects.
1571 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1572 ** New attribute 'name' for gdb.Type objects.
1576 Nios II ELF nios2*-*-elf
1577 Nios II GNU/Linux nios2*-*-linux
1578 Texas Instruments MSP430 msp430*-*-elf
1580 * Removed native configurations
1582 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1583 been removed. ELF variants of these configurations are kept supported.
1585 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1586 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1587 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1588 i[34567]86-*-openbsd3.[0-3]
1589 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1590 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1591 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1595 Like "catch throw", but catches a re-thrown exception.
1596 maint check-psymtabs
1597 Renamed from old "maint check-symtabs".
1599 Perform consistency checks on symtabs.
1600 maint expand-symtabs
1601 Expand symtabs matching an optional regexp.
1604 Display the details of GDB configure-time options.
1606 maint set|show per-command
1607 maint set|show per-command space
1608 maint set|show per-command time
1609 maint set|show per-command symtab
1610 Enable display of per-command gdb resource usage.
1612 remove-symbol-file FILENAME
1613 remove-symbol-file -a ADDRESS
1614 Remove a symbol file added via add-symbol-file. The file to remove
1615 can be identified by its filename or by an address that lies within
1616 the boundaries of this symbol file in memory.
1619 info exceptions REGEXP
1620 Display the list of Ada exceptions defined in the program being
1621 debugged. If provided, only the exceptions whose names match REGEXP
1626 set debug symfile off|on
1628 Control display of debugging info regarding reading symbol files and
1629 symbol tables within those files
1631 set print raw frame-arguments
1632 show print raw frame-arguments
1633 Set/show whether to print frame arguments in raw mode,
1634 disregarding any defined pretty-printers.
1636 set remote trace-status-packet
1637 show remote trace-status-packet
1638 Set/show the use of remote protocol qTStatus packet.
1642 Control display of debugging messages related to Nios II targets.
1646 Control whether target-assisted range stepping is enabled.
1648 set startup-with-shell
1649 show startup-with-shell
1650 Specifies whether Unix child processes are started via a shell or
1655 Use the target memory cache for accesses to the code segment. This
1656 improves performance of remote debugging (particularly disassembly).
1658 * You can now use a literal value 'unlimited' for options that
1659 interpret 0 or -1 as meaning "unlimited". E.g., "set
1660 trace-buffer-size unlimited" is now an alias for "set
1661 trace-buffer-size -1" and "set height unlimited" is now an alias for
1664 * The "set debug symtab-create" debugging option of GDB has been changed to
1665 accept a verbosity level. 0 means "off", 1 provides basic debugging
1666 output, and values of 2 or greater provides more verbose output.
1668 * New command-line options
1670 Display the details of GDB configure-time options.
1672 * The command 'tsave' can now support new option '-ctf' to save trace
1673 buffer in Common Trace Format.
1675 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1678 * GDB now implements the the C++ 'typeid' operator.
1680 * The new convenience variable $_exception holds the exception being
1681 thrown or caught at an exception-related catchpoint.
1683 * The exception-related catchpoints, like "catch throw", now accept a
1684 regular expression which can be used to filter exceptions by type.
1686 * The new convenience variable $_exitsignal is automatically set to
1687 the terminating signal number when the program being debugged dies
1688 due to an uncaught signal.
1692 ** All MI commands now accept an optional "--language" option.
1693 Support for this feature can be verified by using the "-list-features"
1694 command, which should contain "language-option".
1696 ** The new command -info-gdb-mi-command allows the user to determine
1697 whether a GDB/MI command is supported or not.
1699 ** The "^error" result record returned when trying to execute an undefined
1700 GDB/MI command now provides a variable named "code" whose content is the
1701 "undefined-command" error code. Support for this feature can be verified
1702 by using the "-list-features" command, which should contain
1703 "undefined-command-error-code".
1705 ** The -trace-save MI command can optionally save trace buffer in Common
1708 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1710 ** The command -data-list-register-values now accepts an optional
1711 "--skip-unavailable" option. When used, only the available registers
1714 ** The new command -trace-frame-collected dumps collected variables,
1715 computed expressions, tvars, memory and registers in a traceframe.
1717 ** The commands -stack-list-locals, -stack-list-arguments and
1718 -stack-list-variables now accept an option "--skip-unavailable".
1719 When used, only the available locals or arguments are displayed.
1721 ** The -exec-run command now accepts an optional "--start" option.
1722 When used, the command follows the same semantics as the "start"
1723 command, stopping the program's execution at the start of its
1724 main subprogram. Support for this feature can be verified using
1725 the "-list-features" command, which should contain
1726 "exec-run-start-option".
1728 ** The new commands -catch-assert and -catch-exceptions insert
1729 catchpoints stopping the program when Ada exceptions are raised.
1731 ** The new command -info-ada-exceptions provides the equivalent of
1732 the new "info exceptions" command.
1734 * New system-wide configuration scripts
1735 A GDB installation now provides scripts suitable for use as system-wide
1736 configuration scripts for the following systems:
1740 * GDB now supports target-assigned range stepping with remote targets.
1741 This improves the performance of stepping source lines by reducing
1742 the number of control packets from/to GDB. See "New remote packets"
1745 * GDB now understands the element 'tvar' in the XML traceframe info.
1746 It has the id of the collected trace state variables.
1748 * On S/390 targets that provide the transactional-execution feature,
1749 the program interruption transaction diagnostic block (TDB) is now
1750 represented as a number of additional "registers" in GDB.
1752 * New remote packets
1756 The vCont packet supports a new 'r' action, that tells the remote
1757 stub to step through an address range itself, without GDB
1758 involvemement at each single-step.
1760 qXfer:libraries-svr4:read's annex
1761 The previously unused annex of the qXfer:libraries-svr4:read packet
1762 is now used to support passing an argument list. The remote stub
1763 reports support for this argument list to GDB's qSupported query.
1764 The defined arguments are "start" and "prev", used to reduce work
1765 necessary for library list updating, resulting in significant
1768 * New features in the GDB remote stub, GDBserver
1770 ** GDBserver now supports target-assisted range stepping. Currently
1771 enabled on x86/x86_64 GNU/Linux targets.
1773 ** GDBserver now adds element 'tvar' in the XML in the reply to
1774 'qXfer:traceframe-info:read'. It has the id of the collected
1775 trace state variables.
1777 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1780 * New 'z' formatter for printing and examining memory, this displays the
1781 value as hexadecimal zero padded on the left to the size of the type.
1783 * GDB can now use Windows x64 unwinding data.
1785 * The "set remotebaud" command has been replaced by "set serial baud".
1786 Similarly, "show remotebaud" has been replaced by "show serial baud".
1787 The "set remotebaud" and "show remotebaud" commands are still available
1788 to provide backward compatibility with older versions of GDB.
1790 *** Changes in GDB 7.6
1792 * Target record has been renamed to record-full.
1793 Record/replay is now enabled with the "record full" command.
1794 This also affects settings that are associated with full record/replay
1795 that have been moved from "set/show record" to "set/show record full":
1797 set|show record full insn-number-max
1798 set|show record full stop-at-limit
1799 set|show record full memory-query
1801 * A new record target "record-btrace" has been added. The new target
1802 uses hardware support to record the control-flow of a process. It
1803 does not support replaying the execution, but it implements the
1804 below new commands for investigating the recorded execution log.
1805 This new recording method can be enabled using:
1809 The "record-btrace" target is only available on Intel Atom processors
1810 and requires a Linux kernel 2.6.32 or later.
1812 * Two new commands have been added for record/replay to give information
1813 about the recorded execution without having to replay the execution.
1814 The commands are only supported by "record btrace".
1816 record instruction-history prints the execution history at
1817 instruction granularity
1819 record function-call-history prints the execution history at
1820 function granularity
1822 * New native configurations
1824 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1825 FreeBSD/powerpc powerpc*-*-freebsd
1826 x86_64/Cygwin x86_64-*-cygwin*
1827 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1831 ARM AArch64 aarch64*-*-elf
1832 ARM AArch64 GNU/Linux aarch64*-*-linux
1833 Lynx 178 PowerPC powerpc-*-lynx*178
1834 x86_64/Cygwin x86_64-*-cygwin*
1835 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1837 * If the configured location of system.gdbinit file (as given by the
1838 --with-system-gdbinit option at configure time) is in the
1839 data-directory (as specified by --with-gdb-datadir at configure
1840 time) or in one of its subdirectories, then GDB will look for the
1841 system-wide init file in the directory specified by the
1842 --data-directory command-line option.
1844 * New command line options:
1846 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1847 other initialization files, unlike -nx which disables all of them.
1849 * Removed command line options
1851 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1854 * The 'ptype' and 'whatis' commands now accept an argument to control
1857 * 'info proc' now works on some core files.
1861 ** Vectors can be created with gdb.Type.vector.
1863 ** Python's atexit.register now works in GDB.
1865 ** Types can be pretty-printed via a Python API.
1867 ** Python 3 is now supported (in addition to Python 2.4 or later)
1869 ** New class gdb.Architecture exposes GDB's internal representation
1870 of architecture in the Python API.
1872 ** New method Frame.architecture returns the gdb.Architecture object
1873 corresponding to the frame's architecture.
1875 * New Python-based convenience functions:
1877 ** $_memeq(buf1, buf2, length)
1878 ** $_streq(str1, str2)
1880 ** $_regex(str, regex)
1882 * The 'cd' command now defaults to using '~' (the home directory) if not
1885 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1886 default for GCC since November 2000.
1888 * The command 'forward-search' can now be abbreviated as 'fo'.
1890 * The command 'info tracepoints' can now display 'installed on target'
1891 or 'not installed on target' for each non-pending location of tracepoint.
1893 * New configure options
1895 --enable-libmcheck/--disable-libmcheck
1896 By default, development versions are built with -lmcheck on hosts
1897 that support it, in order to help track memory corruption issues.
1898 Release versions, on the other hand, are built without -lmcheck
1899 by default. The --enable-libmcheck/--disable-libmcheck configure
1900 options allow the user to override that default.
1901 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1902 This configure option allows the user to build GDB with
1903 libbabeltrace using which GDB can read Common Trace Format data.
1905 * New commands (for set/show, see "New options" below)
1908 Catch signals. This is similar to "handle", but allows commands and
1909 conditions to be attached.
1912 List the BFDs known to GDB.
1914 python-interactive [command]
1916 Start a Python interactive prompt, or evaluate the optional command
1917 and print the result of expressions.
1920 "py" is a new alias for "python".
1922 enable type-printer [name]...
1923 disable type-printer [name]...
1924 Enable or disable type printers.
1928 ** For the Renesas Super-H architecture, the "regs" command has been removed
1929 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1934 set print type methods (on|off)
1935 show print type methods
1936 Control whether method declarations are displayed by "ptype".
1937 The default is to show them.
1939 set print type typedefs (on|off)
1940 show print type typedefs
1941 Control whether typedef definitions are displayed by "ptype".
1942 The default is to show them.
1944 set filename-display basename|relative|absolute
1945 show filename-display
1946 Control the way in which filenames is displayed.
1947 The default is "relative", which preserves previous behavior.
1949 set trace-buffer-size
1950 show trace-buffer-size
1951 Request target to change the size of trace buffer.
1953 set remote trace-buffer-size-packet auto|on|off
1954 show remote trace-buffer-size-packet
1955 Control the use of the remote protocol `QTBuffer:size' packet.
1959 Control display of debugging messages related to ARM AArch64.
1962 set debug coff-pe-read
1963 show debug coff-pe-read
1964 Control display of debugging messages related to reading of COFF/PE
1969 Control display of debugging messages related to Mach-O symbols
1972 set debug notification
1973 show debug notification
1974 Control display of debugging info for async remote notification.
1978 ** Command parameter changes are now notified using new async record
1979 "=cmd-param-changed".
1980 ** Trace frame changes caused by command "tfind" are now notified using
1981 new async record "=traceframe-changed".
1982 ** The creation, deletion and modification of trace state variables
1983 are now notified using new async records "=tsv-created",
1984 "=tsv-deleted" and "=tsv-modified".
1985 ** The start and stop of process record are now notified using new
1986 async record "=record-started" and "=record-stopped".
1987 ** Memory changes are now notified using new async record
1989 ** The data-disassemble command response will include a "fullname" field
1990 containing the absolute file name when source has been requested.
1991 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1992 command, to allow pattern filling of memory areas.
1993 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1994 library load/unload events.
1995 ** The response to breakpoint commands and breakpoint async records
1996 includes an "installed" field containing a boolean state about each
1997 non-pending tracepoint location is whether installed on target or not.
1998 ** Output of the "-trace-status" command includes a "trace-file" field
1999 containing the name of the trace file being examined. This field is
2000 optional, and only present when examining a trace file.
2001 ** The "fullname" field is now always present along with the "file" field,
2002 even if the file cannot be found by GDB.
2004 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2005 You must have the LZMA library available when configuring GDB for this
2006 feature to be enabled. For more information, see:
2007 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2009 * New remote packets
2012 Set the size of trace buffer. The remote stub reports support for this
2013 packet to gdb's qSupported query.
2016 Enable Branch Trace Store (BTS)-based branch tracing for the current
2017 thread. The remote stub reports support for this packet to gdb's
2021 Disable branch tracing for the current thread. The remote stub reports
2022 support for this packet to gdb's qSupported query.
2025 Read the traced branches for the current thread. The remote stub
2026 reports support for this packet to gdb's qSupported query.
2028 *** Changes in GDB 7.5
2030 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2031 for more x32 ABI info.
2033 * GDB now supports access to MIPS DSP registers on Linux targets.
2035 * GDB now supports debugging microMIPS binaries.
2037 * The "info os" command on GNU/Linux can now display information on
2038 several new classes of objects managed by the operating system:
2039 "info os procgroups" lists process groups
2040 "info os files" lists file descriptors
2041 "info os sockets" lists internet-domain sockets
2042 "info os shm" lists shared-memory regions
2043 "info os semaphores" lists semaphores
2044 "info os msg" lists message queues
2045 "info os modules" lists loaded kernel modules
2047 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2048 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2049 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2050 options and inspect the probe arguments using the new $_probe_arg family
2051 of convenience variables. You can obtain more information about SystemTap
2052 in <http://sourceware.org/systemtap/>.
2054 * GDB now supports reversible debugging on ARM, it allows you to
2055 debug basic ARM and THUMB instructions, and provides
2056 record/replay support.
2058 * The option "symbol-reloading" has been deleted as it is no longer used.
2062 ** GDB commands implemented in Python can now be put in command class
2065 ** The "maint set python print-stack on|off" is now deleted.
2067 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2068 apply "flag enum"-style pretty-printing to any enum.
2070 ** gdb.lookup_symbol can now work when there is no current frame.
2072 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2073 the source at which the symbol was defined.
2075 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2076 method 'value'. The former indicates whether the symbol needs a
2077 frame in order to compute its value, and the latter computes the
2080 ** A new method 'referenced_value' on gdb.Value objects which can
2081 dereference pointer as well as C++ reference values.
2083 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2084 which return the global and static blocks (as gdb.Block objects),
2085 of the underlying symbol table, respectively.
2087 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2088 object associated with a PC value.
2090 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2091 of the address range occupied by code for the current source line.
2093 * Go language support.
2094 GDB now supports debugging programs written in the Go programming
2097 * GDBserver now supports stdio connections.
2098 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2100 * The binary "gdbtui" can no longer be built or installed.
2101 Use "gdb -tui" instead.
2103 * GDB will now print "flag" enums specially. A flag enum is one where
2104 all the enumerator values have no bits in common when pairwise
2105 "and"ed. When printing a value whose type is a flag enum, GDB will
2106 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2107 (gdb) print (enum E) 3
2110 * The filename part of a linespec will now match trailing components
2111 of a source file name. For example, "break gcc/expr.c:1000" will
2112 now set a breakpoint in build/gcc/expr.c, but not
2113 build/libcpp/expr.c.
2115 * The "info proc" and "generate-core-file" commands will now also
2116 work on remote targets connected to GDBserver on Linux.
2118 * The command "info catch" has been removed. It has been disabled
2119 since December 2007.
2121 * The "catch exception" and "catch assert" commands now accept
2122 a condition at the end of the command, much like the "break"
2123 command does. For instance:
2125 (gdb) catch exception Constraint_Error if Barrier = True
2127 Previously, it was possible to add a condition to such catchpoints,
2128 but it had to be done as a second step, after the catchpoint had been
2129 created, using the "condition" command.
2131 * The "info static-tracepoint-marker" command will now also work on
2132 native Linux targets with in-process agent.
2134 * GDB can now set breakpoints on inlined functions.
2136 * The .gdb_index section has been updated to include symbols for
2137 inlined functions. GDB will ignore older .gdb_index sections by
2138 default, which could cause symbol files to be loaded more slowly
2139 until their .gdb_index sections can be recreated. The new command
2140 "set use-deprecated-index-sections on" will cause GDB to use any older
2141 .gdb_index sections it finds. This will restore performance, but the
2142 ability to set breakpoints on inlined functions will be lost in symbol
2143 files with older .gdb_index sections.
2145 The .gdb_index section has also been updated to record more information
2146 about each symbol. This speeds up the "info variables", "info functions"
2147 and "info types" commands when used with programs having the .gdb_index
2148 section, as well as speeding up debugging with shared libraries using
2149 the .gdb_index section.
2151 * Ada support for GDB/MI Variable Objects has been added.
2153 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2158 ** New command -info-os is the MI equivalent of "info os".
2160 ** Output logs ("set logging" and related) now include MI output.
2164 ** "set use-deprecated-index-sections on|off"
2165 "show use-deprecated-index-sections on|off"
2166 Controls the use of deprecated .gdb_index sections.
2168 ** "catch load" and "catch unload" can be used to stop when a shared
2169 library is loaded or unloaded, respectively.
2171 ** "enable count" can be used to auto-disable a breakpoint after
2174 ** "info vtbl" can be used to show the virtual method tables for
2175 C++ and Java objects.
2177 ** "explore" and its sub commands "explore value" and "explore type"
2178 can be used to recursively explore values and types of
2179 expressions. These commands are available only if GDB is
2180 configured with '--with-python'.
2182 ** "info auto-load" shows status of all kinds of auto-loaded files,
2183 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2184 sequences of commands files, "info auto-load python-scripts"
2185 shows status of auto-loading Python script files,
2186 "info auto-load local-gdbinit" shows status of loading init file
2187 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2188 status of inferior specific thread debugging shared library loading.
2190 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2191 and "show auto-load-scripts" commands have been deprecated, use their
2192 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2193 and "show auto-load python-scripts" counterparts instead.
2195 ** "dprintf location,format,args..." creates a dynamic printf, which
2196 is basically a breakpoint that does a printf and immediately
2197 resumes your program's execution, so it is like a printf that you
2198 can insert dynamically at runtime instead of at compiletime.
2200 ** "set print symbol"
2202 Controls whether GDB attempts to display the symbol, if any,
2203 corresponding to addresses it prints. This defaults to "on", but
2204 you can set it to "off" to restore GDB's previous behavior.
2206 * Deprecated commands
2208 ** For the Renesas Super-H architecture, the "regs" command has been
2209 deprecated, and "info all-registers" should be used instead.
2213 Renesas RL78 rl78-*-elf
2214 HP OpenVMS ia64 ia64-hp-openvms*
2216 * GDBserver supports evaluation of breakpoint conditions. When
2217 support is advertised by GDBserver, GDB may be told to send the
2218 breakpoint conditions in bytecode form to GDBserver. GDBserver
2219 will only report the breakpoint trigger to GDB when its condition
2224 set mips compression
2225 show mips compression
2226 Select the compressed ISA encoding used in functions that have no symbol
2227 information available. The encoding can be set to either of:
2230 and is updated automatically from ELF file flags if available.
2232 set breakpoint condition-evaluation
2233 show breakpoint condition-evaluation
2234 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2235 GDBserver ("target"). Default option "auto" chooses the most efficient
2237 This option can improve debugger efficiency depending on the speed of the
2241 Disable auto-loading globally.
2244 Show auto-loading setting of all kinds of auto-loaded files.
2246 set auto-load gdb-scripts on|off
2247 show auto-load gdb-scripts
2248 Control auto-loading of GDB canned sequences of commands files.
2250 set auto-load python-scripts on|off
2251 show auto-load python-scripts
2252 Control auto-loading of Python script files.
2254 set auto-load local-gdbinit on|off
2255 show auto-load local-gdbinit
2256 Control loading of init file (.gdbinit) from current directory.
2258 set auto-load libthread-db on|off
2259 show auto-load libthread-db
2260 Control auto-loading of inferior specific thread debugging shared library.
2262 set auto-load scripts-directory <dir1>[:<dir2>...]
2263 show auto-load scripts-directory
2264 Set a list of directories from which to load auto-loaded scripts.
2265 Automatically loaded Python scripts and GDB scripts are located in one
2266 of the directories listed by this option.
2267 The delimiter (':' above) may differ according to the host platform.
2269 set auto-load safe-path <dir1>[:<dir2>...]
2270 show auto-load safe-path
2271 Set a list of directories from which it is safe to auto-load files.
2272 The delimiter (':' above) may differ according to the host platform.
2274 set debug auto-load on|off
2275 show debug auto-load
2276 Control display of debugging info for auto-loading the files above.
2278 set dprintf-style gdb|call|agent
2280 Control the way in which a dynamic printf is performed; "gdb"
2281 requests a GDB printf command, while "call" causes dprintf to call a
2282 function in the inferior. "agent" requests that the target agent
2283 (such as GDBserver) do the printing.
2285 set dprintf-function <expr>
2286 show dprintf-function
2287 set dprintf-channel <expr>
2288 show dprintf-channel
2289 Set the function and optional first argument to the call when using
2290 the "call" style of dynamic printf.
2292 set disconnected-dprintf on|off
2293 show disconnected-dprintf
2294 Control whether agent-style dynamic printfs continue to be in effect
2295 after GDB disconnects.
2297 * New configure options
2299 --with-auto-load-dir
2300 Configure default value for the 'set auto-load scripts-directory'
2301 setting above. It defaults to '$debugdir:$datadir/auto-load',
2302 $debugdir representing global debugging info directories (available
2303 via 'show debug-file-directory') and $datadir representing GDB's data
2304 directory (available via 'show data-directory').
2306 --with-auto-load-safe-path
2307 Configure default value for the 'set auto-load safe-path' setting
2308 above. It defaults to the --with-auto-load-dir setting.
2310 --without-auto-load-safe-path
2311 Set 'set auto-load safe-path' to '/', effectively disabling this
2314 * New remote packets
2316 z0/z1 conditional breakpoints extension
2318 The z0/z1 breakpoint insertion packets have been extended to carry
2319 a list of conditional expressions over to the remote stub depending on the
2320 condition evaluation mode. The use of this extension can be controlled
2321 via the "set remote conditional-breakpoints-packet" command.
2325 Specify the signals which the remote stub may pass to the debugged
2326 program without GDB involvement.
2328 * New command line options
2330 --init-command=FILE, -ix Like --command, -x but execute it
2331 before loading inferior.
2332 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2333 execute it before loading inferior.
2335 *** Changes in GDB 7.4
2337 * GDB now handles ambiguous linespecs more consistently; the existing
2338 FILE:LINE support has been expanded to other types of linespecs. A
2339 breakpoint will now be set on all matching locations in all
2340 inferiors, and locations will be added or removed according to
2343 * GDB now allows you to skip uninteresting functions and files when
2344 stepping with the "skip function" and "skip file" commands.
2346 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2347 and "show remote hardware-watchpoint-length-limit". These allows to
2348 set or show the maximum length limit (in bytes) of a remote
2349 target hardware watchpoint.
2351 This allows e.g. to use "unlimited" hardware watchpoints with the
2352 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2353 watchpoints are slower than real hardware watchpoints but are
2354 significantly faster than gdb software watchpoints.
2358 ** The register_pretty_printer function in module gdb.printing now takes
2359 an optional `replace' argument. If True, the new printer replaces any
2362 ** The "maint set python print-stack on|off" command has been
2363 deprecated and will be deleted in GDB 7.5.
2364 A new command: "set python print-stack none|full|message" has
2365 replaced it. Additionally, the default for "print-stack" is
2366 now "message", which just prints the error message without
2369 ** A prompt substitution hook (prompt_hook) is now available to the
2372 ** A new Python module, gdb.prompt has been added to the GDB Python
2373 modules library. This module provides functionality for
2374 escape sequences in prompts (used by set/show
2375 extended-prompt). These escape sequences are replaced by their
2376 corresponding value.
2378 ** Python commands and convenience-functions located in
2379 'data-directory'/python/gdb/command and
2380 'data-directory'/python/gdb/function are now automatically loaded
2383 ** Blocks now provide four new attributes. global_block and
2384 static_block will return the global and static blocks
2385 respectively. is_static and is_global are boolean attributes
2386 that indicate if the block is one of those two types.
2388 ** Symbols now provide the "type" attribute, the type of the symbol.
2390 ** The "gdb.breakpoint" function has been deprecated in favor of
2393 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2394 of a function. This class is based on the "finish" command
2395 available in the CLI.
2397 ** Type objects for struct and union types now allow access to
2398 the fields using standard Python dictionary (mapping) methods.
2399 For example, "some_type['myfield']" now works, as does
2400 "some_type.items()".
2402 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2405 ** A new function, "deep_items" has been added to the gdb.types
2406 module in the GDB Python modules library. This function returns
2407 an iterator over the fields of a struct or union type. Unlike
2408 the standard Python "iteritems" method, it will recursively traverse
2409 any anonymous fields.
2413 ** "*stopped" events can report several new "reason"s, such as
2416 ** Breakpoint changes are now notified using new async records, like
2417 "=breakpoint-modified".
2419 ** New command -ada-task-info.
2421 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2422 $sdir specifies the default system locations of shared libraries.
2423 $pdir specifies the directory where the libpthread used by the application
2426 GDB no longer looks in $sdir and $pdir after it has searched the directories
2427 mentioned in libthread-db-search-path. If you want to search those
2428 directories, they must be specified in libthread-db-search-path.
2429 The default value of libthread-db-search-path on GNU/Linux and Solaris
2430 systems is now "$sdir:$pdir".
2432 $pdir is not supported by gdbserver, it is currently ignored.
2433 $sdir is supported by gdbserver.
2435 * New configure option --with-iconv-bin.
2436 When using the internationalization support like the one in the GNU C
2437 library, GDB will invoke the "iconv" program to get a list of supported
2438 character sets. If this program lives in a non-standard location, one can
2439 use this option to specify where to find it.
2441 * When natively debugging programs on PowerPC BookE processors running
2442 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2443 watchpoints, which specify a mask in addition to an address to watch.
2444 The mask specifies that some bits of an address (the bits which are
2445 reset in the mask) should be ignored when matching the address accessed
2446 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2447 section in the user manual for more details.
2449 * The new option --once causes GDBserver to stop listening for connections once
2450 the first connection is made. The listening port used by GDBserver will
2451 become available after that.
2453 * New commands "info macros" and "alias" have been added.
2455 * New function parameters suffix @entry specifies value of function parameter
2456 at the time the function got called. Entry values are available only since
2462 "!" is now an alias of the "shell" command.
2463 Note that no space is needed between "!" and SHELL COMMAND.
2467 watch EXPRESSION mask MASK_VALUE
2468 The watch command now supports the mask argument which allows creation
2469 of masked watchpoints, if the current architecture supports this feature.
2471 info auto-load-scripts [REGEXP]
2472 This command was formerly named "maintenance print section-scripts".
2473 It is now generally useful and is no longer a maintenance-only command.
2475 info macro [-all] [--] MACRO
2476 The info macro command has new options `-all' and `--'. The first for
2477 printing all definitions of a macro. The second for explicitly specifying
2478 the end of arguments and the beginning of the macro name in case the macro
2479 name starts with a hyphen.
2481 collect[/s] EXPRESSIONS
2482 The tracepoint collect command now takes an optional modifier "/s"
2483 that directs it to dereference pointer-to-character types and
2484 collect the bytes of memory up to a zero byte. The behavior is
2485 similar to what you see when you use the regular print command on a
2486 string. An optional integer following the "/s" sets a bound on the
2487 number of bytes that will be collected.
2490 The trace start command now interprets any supplied arguments as a
2491 note to be recorded with the trace run, with an effect similar to
2492 setting the variable trace-notes.
2495 The trace stop command now interprets any arguments as a note to be
2496 mentioned along with the tstatus report that the trace was stopped
2497 with a command. The effect is similar to setting the variable
2500 * Tracepoints can now be enabled and disabled at any time after a trace
2501 experiment has been started using the standard "enable" and "disable"
2502 commands. It is now possible to start a trace experiment with no enabled
2503 tracepoints; GDB will display a warning, but will allow the experiment to
2504 begin, assuming that tracepoints will be enabled as needed while the trace
2507 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2508 locations with 4-byte instructions, when they were previously
2509 limited to locations with instructions of 5 bytes or longer.
2513 set debug dwarf2-read
2514 show debug dwarf2-read
2515 Turns on or off display of debugging messages related to reading
2516 DWARF debug info. The default is off.
2518 set debug symtab-create
2519 show debug symtab-create
2520 Turns on or off display of debugging messages related to symbol table
2521 creation. The default is off.
2524 show extended-prompt
2525 Set the GDB prompt, and allow escape sequences to be inserted to
2526 display miscellaneous information (see 'help set extended-prompt'
2527 for the list of sequences). This prompt (and any information
2528 accessed through the escape sequences) is updated every time the
2529 prompt is displayed.
2531 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2532 show print entry-values
2533 Set printing of frame argument values at function entry. In some cases
2534 GDB can determine the value of function argument which was passed by the
2535 function caller, even if the value was modified inside the called function.
2537 set debug entry-values
2538 show debug entry-values
2539 Control display of debugging info for determining frame argument values at
2540 function entry and virtual tail call frames.
2542 set basenames-may-differ
2543 show basenames-may-differ
2544 Set whether a source file may have multiple base names.
2545 (A "base name" is the name of a file with the directory part removed.
2546 Example: The base name of "/home/user/hello.c" is "hello.c".)
2547 If set, GDB will canonicalize file names (e.g., expand symlinks)
2548 before comparing them. Canonicalization is an expensive operation,
2549 but it allows the same file be known by more than one base name.
2550 If not set (the default), all source files are assumed to have just
2551 one base name, and gdb will do file name comparisons more efficiently.
2557 Set a user name and notes for the current and any future trace runs.
2558 This is useful for long-running and/or disconnected traces, to
2559 inform others (or yourself) as to who is running the trace, supply
2560 contact information, or otherwise explain what is going on.
2562 set trace-stop-notes
2563 show trace-stop-notes
2564 Set a note attached to the trace run, that is displayed when the
2565 trace has been stopped by a tstop command. This is useful for
2566 instance as an explanation, if you are stopping a trace run that was
2567 started by someone else.
2569 * New remote packets
2573 Dynamically enable a tracepoint in a started trace experiment.
2577 Dynamically disable a tracepoint in a started trace experiment.
2581 Set the user and notes of the trace run.
2585 Query the current status of a tracepoint.
2589 Query the minimum length of instruction at which a fast tracepoint may
2592 * Dcache size (number of lines) and line-size are now runtime-configurable
2593 via "set dcache line" and "set dcache line-size" commands.
2597 Texas Instruments TMS320C6x tic6x-*-*
2601 Renesas RL78 rl78-*-elf
2603 *** Changes in GDB 7.3.1
2605 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2607 *** Changes in GDB 7.3
2609 * GDB has a new command: "thread find [REGEXP]".
2610 It finds the thread id whose name, target id, or thread extra info
2611 matches the given regular expression.
2613 * The "catch syscall" command now works on mips*-linux* targets.
2615 * The -data-disassemble MI command now supports modes 2 and 3 for
2616 dumping the instruction opcodes.
2618 * New command line options
2620 -data-directory DIR Specify DIR as the "data-directory".
2621 This is mostly for testing purposes.
2623 * The "maint set python auto-load on|off" command has been renamed to
2624 "set auto-load-scripts on|off".
2626 * GDB has a new command: "set directories".
2627 It is like the "dir" command except that it replaces the
2628 source path list instead of augmenting it.
2630 * GDB now understands thread names.
2632 On GNU/Linux, "info threads" will display the thread name as set by
2633 prctl or pthread_setname_np.
2635 There is also a new command, "thread name", which can be used to
2636 assign a name internally for GDB to display.
2639 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2640 has been integrated into GDB.
2644 ** The function gdb.Write now accepts an optional keyword 'stream'.
2645 This keyword, when provided, will direct the output to either
2646 stdout, stderr, or GDB's logging output.
2648 ** Parameters can now be be sub-classed in Python, and in particular
2649 you may implement the get_set_doc and get_show_doc functions.
2650 This improves how Parameter set/show documentation is processed
2651 and allows for more dynamic content.
2653 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2654 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2655 have an is_valid method.
2657 ** Breakpoints can now be sub-classed in Python, and in particular
2658 you may implement a 'stop' function that is executed each time
2659 the inferior reaches that breakpoint.
2661 ** New function gdb.lookup_global_symbol looks up a global symbol.
2663 ** GDB values in Python are now callable if the value represents a
2664 function. For example, if 'some_value' represents a function that
2665 takes two integer parameters and returns a value, you can call
2666 that function like so:
2668 result = some_value (10,20)
2670 ** Module gdb.types has been added.
2671 It contains a collection of utilities for working with gdb.Types objects:
2672 get_basic_type, has_field, make_enum_dict.
2674 ** Module gdb.printing has been added.
2675 It contains utilities for writing and registering pretty-printers.
2676 New classes: PrettyPrinter, SubPrettyPrinter,
2677 RegexpCollectionPrettyPrinter.
2678 New function: register_pretty_printer.
2680 ** New commands "info pretty-printers", "enable pretty-printer" and
2681 "disable pretty-printer" have been added.
2683 ** gdb.parameter("directories") is now available.
2685 ** New function gdb.newest_frame returns the newest frame in the
2688 ** The gdb.InferiorThread class has a new "name" attribute. This
2689 holds the thread's name.
2691 ** Python Support for Inferior events.
2692 Python scripts can add observers to be notified of events
2693 occurring in the process being debugged.
2694 The following events are currently supported:
2695 - gdb.events.cont Continue event.
2696 - gdb.events.exited Inferior exited event.
2697 - gdb.events.stop Signal received, and Breakpoint hit events.
2701 ** GDB now puts template parameters in scope when debugging in an
2702 instantiation. For example, if you have:
2704 template<int X> int func (void) { return X; }
2706 then if you step into func<5>, "print X" will show "5". This
2707 feature requires proper debuginfo support from the compiler; it
2708 was added to GCC 4.5.
2710 ** The motion commands "next", "finish", "until", and "advance" now
2711 work better when exceptions are thrown. In particular, GDB will
2712 no longer lose control of the inferior; instead, the GDB will
2713 stop the inferior at the point at which the exception is caught.
2714 This functionality requires a change in the exception handling
2715 code that was introduced in GCC 4.5.
2717 * GDB now follows GCC's rules on accessing volatile objects when
2718 reading or writing target state during expression evaluation.
2719 One notable difference to prior behavior is that "print x = 0"
2720 no longer generates a read of x; the value of the assignment is
2721 now always taken directly from the value being assigned.
2723 * GDB now has some support for using labels in the program's source in
2724 linespecs. For instance, you can use "advance label" to continue
2725 execution to a label.
2727 * GDB now has support for reading and writing a new .gdb_index
2728 section. This section holds a fast index of DWARF debugging
2729 information and can be used to greatly speed up GDB startup and
2730 operation. See the documentation for `save gdb-index' for details.
2732 * The "watch" command now accepts an optional "-location" argument.
2733 When used, this causes GDB to watch the memory referred to by the
2734 expression. Such a watchpoint is never deleted due to it going out
2737 * GDB now supports thread debugging of core dumps on GNU/Linux.
2739 GDB now activates thread debugging using the libthread_db library
2740 when debugging GNU/Linux core dumps, similarly to when debugging
2741 live processes. As a result, when debugging a core dump file, GDB
2742 is now able to display pthread_t ids of threads. For example, "info
2743 threads" shows the same output as when debugging the process when it
2744 was live. In earlier releases, you'd see something like this:
2747 * 1 LWP 6780 main () at main.c:10
2749 While now you see this:
2752 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2754 It is also now possible to inspect TLS variables when debugging core
2757 When debugging a core dump generated on a machine other than the one
2758 used to run GDB, you may need to point GDB at the correct
2759 libthread_db library with the "set libthread-db-search-path"
2760 command. See the user manual for more details on this command.
2762 * When natively debugging programs on PowerPC BookE processors running
2763 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2764 which stop execution of the inferior whenever it executes an instruction
2765 at any address within the specified range. See the "PowerPC Embedded"
2766 section in the user manual for more details.
2768 * New features in the GDB remote stub, GDBserver
2770 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2771 and i686 LynxOS (version 5.x).
2773 ** GDBserver is now supported on Blackfin Linux.
2775 * New native configurations
2777 ia64 HP-UX ia64-*-hpux*
2781 Analog Devices, Inc. Blackfin Processor bfin-*
2783 * Ada task switching is now supported on sparc-elf targets when
2784 debugging a program using the Ravenscar Profile. For more information,
2785 see the "Tasking Support when using the Ravenscar Profile" section
2786 in the GDB user manual.
2788 * Guile support was removed.
2790 * New features in the GNU simulator
2792 ** The --map-info flag lists all known core mappings.
2794 ** CFI flashes may be simulated via the "cfi" device.
2796 *** Changes in GDB 7.2
2798 * Shared library support for remote targets by default
2800 When GDB is configured for a generic, non-OS specific target, like
2801 for example, --target=arm-eabi or one of the many *-*-elf targets,
2802 GDB now queries remote stubs for loaded shared libraries using the
2803 `qXfer:libraries:read' packet. Previously, shared library support
2804 was always disabled for such configurations.
2808 ** Argument Dependent Lookup (ADL)
2810 In C++ ADL lookup directs function search to the namespaces of its
2811 arguments even if the namespace has not been imported.
2821 Here the compiler will search for `foo' in the namespace of 'b'
2822 and find A::foo. GDB now supports this. This construct is commonly
2823 used in the Standard Template Library for operators.
2825 ** Improved User Defined Operator Support
2827 In addition to member operators, GDB now supports lookup of operators
2828 defined in a namespace and imported with a `using' directive, operators
2829 defined in the global scope, operators imported implicitly from an
2830 anonymous namespace, and the ADL operators mentioned in the previous
2832 GDB now also supports proper overload resolution for all the previously
2833 mentioned flavors of operators.
2835 ** static const class members
2837 Printing of static const class members that are initialized in the
2838 class definition has been fixed.
2840 * Windows Thread Information Block access.
2842 On Windows targets, GDB now supports displaying the Windows Thread
2843 Information Block (TIB) structure. This structure is visible either
2844 by using the new command `info w32 thread-information-block' or, by
2845 dereferencing the new convenience variable named `$_tlb', a
2846 thread-specific pointer to the TIB. This feature is also supported
2847 when remote debugging using GDBserver.
2849 * Static tracepoints
2851 Static tracepoints are calls in the user program into a tracing
2852 library. One such library is a port of the LTTng kernel tracer to
2853 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2854 When debugging with GDBserver, GDB now supports combining the GDB
2855 tracepoint machinery with such libraries. For example: the user can
2856 use GDB to probe a static tracepoint marker (a call from the user
2857 program into the tracing library) with the new "strace" command (see
2858 "New commands" below). This creates a "static tracepoint" in the
2859 breakpoint list, that can be manipulated with the same feature set
2860 as fast and regular tracepoints. E.g., collect registers, local and
2861 global variables, collect trace state variables, and define
2862 tracepoint conditions. In addition, the user can collect extra
2863 static tracepoint marker specific data, by collecting the new
2864 $_sdata internal variable. When analyzing the trace buffer, you can
2865 inspect $_sdata like any other variable available to GDB. For more
2866 information, see the "Tracepoints" chapter in GDB user manual. New
2867 remote packets have been defined to support static tracepoints, see
2868 the "New remote packets" section below.
2870 * Better reconstruction of tracepoints after disconnected tracing
2872 GDB will attempt to download the original source form of tracepoint
2873 definitions when starting a trace run, and then will upload these
2874 upon reconnection to the target, resulting in a more accurate
2875 reconstruction of the tracepoints that are in use on the target.
2879 You can now exercise direct control over the ways that GDB can
2880 affect your program. For instance, you can disallow the setting of
2881 breakpoints, so that the program can run continuously (assuming
2882 non-stop mode). In addition, the "observer" variable is available
2883 to switch all of the different controls; in observer mode, GDB
2884 cannot affect the target's behavior at all, which is useful for
2885 tasks like diagnosing live systems in the field.
2887 * The new convenience variable $_thread holds the number of the
2890 * New remote packets
2894 Return the address of the Windows Thread Information Block of a given thread.
2898 In response to several of the tracepoint packets, the target may now
2899 also respond with a number of intermediate `qRelocInsn' request
2900 packets before the final result packet, to have GDB handle
2901 relocating an instruction to execute at a different address. This
2902 is particularly useful for stubs that support fast tracepoints. GDB
2903 reports support for this feature in the qSupported packet.
2907 List static tracepoint markers in the target program.
2911 List static tracepoint markers at a given address in the target
2914 qXfer:statictrace:read
2916 Read the static trace data collected (by a `collect $_sdata'
2917 tracepoint action). The remote stub reports support for this packet
2918 to gdb's qSupported query.
2922 Send the current settings of GDB's permission flags.
2926 Send part of the source (textual) form of a tracepoint definition,
2927 which includes location, conditional, and action list.
2929 * The source command now accepts a -s option to force searching for the
2930 script in the source search path even if the script name specifies
2933 * New features in the GDB remote stub, GDBserver
2935 - GDBserver now support tracepoints (including fast tracepoints, and
2936 static tracepoints). The feature is currently supported by the
2937 i386-linux and amd64-linux builds. See the "Tracepoints support
2938 in gdbserver" section in the manual for more information.
2940 GDBserver JIT compiles the tracepoint's conditional agent
2941 expression bytecode into native code whenever possible for low
2942 overhead dynamic tracepoints conditionals. For such tracepoints,
2943 an expression that examines program state is evaluated when the
2944 tracepoint is reached, in order to determine whether to capture
2945 trace data. If the condition is simple and false, processing the
2946 tracepoint finishes very quickly and no data is gathered.
2948 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2949 for static tracepoints support.
2951 - GDBserver now supports x86_64 Windows 64-bit debugging.
2953 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2954 it understands register description.
2956 * The --batch flag now disables pagination and queries.
2958 * X86 general purpose registers
2960 GDB now supports reading/writing byte, word and double-word x86
2961 general purpose registers directly. This means you can use, say,
2962 $ah or $ax to refer, respectively, to the byte register AH and
2963 16-bit word register AX that are actually portions of the 32-bit
2964 register EAX or 64-bit register RAX.
2966 * The `commands' command now accepts a range of breakpoints to modify.
2967 A plain `commands' following a command that creates multiple
2968 breakpoints affects all the breakpoints set by that command. This
2969 applies to breakpoints set by `rbreak', and also applies when a
2970 single `break' command creates multiple breakpoints (e.g.,
2971 breakpoints on overloaded c++ functions).
2973 * The `rbreak' command now accepts a filename specification as part of
2974 its argument, limiting the functions selected by the regex to those
2975 in the specified file.
2977 * Support for remote debugging Windows and SymbianOS shared libraries
2978 from Unix hosts has been improved. Non Windows GDB builds now can
2979 understand target reported file names that follow MS-DOS based file
2980 system semantics, such as file names that include drive letters and
2981 use the backslash character as directory separator. This makes it
2982 possible to transparently use the "set sysroot" and "set
2983 solib-search-path" on Unix hosts to point as host copies of the
2984 target's shared libraries. See the new command "set
2985 target-file-system-kind" described below, and the "Commands to
2986 specify files" section in the user manual for more information.
2990 eval template, expressions...
2991 Convert the values of one or more expressions under the control
2992 of the string template to a command line, and call it.
2994 set target-file-system-kind unix|dos-based|auto
2995 show target-file-system-kind
2996 Set or show the assumed file system kind for target reported file
2999 save breakpoints <filename>
3000 Save all current breakpoint definitions to a file suitable for use
3001 in a later debugging session. To read the saved breakpoint
3002 definitions, use the `source' command.
3004 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3007 info static-tracepoint-markers
3008 Display information about static tracepoint markers in the target.
3010 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3011 Define a static tracepoint by probing a marker at the given
3012 function, line, address, or marker ID.
3016 Enable and disable observer mode.
3018 set may-write-registers on|off
3019 set may-write-memory on|off
3020 set may-insert-breakpoints on|off
3021 set may-insert-tracepoints on|off
3022 set may-insert-fast-tracepoints on|off
3023 set may-interrupt on|off
3024 Set individual permissions for GDB effects on the target. Note that
3025 some of these settings can have undesirable or surprising
3026 consequences, particularly when changed in the middle of a session.
3027 For instance, disabling the writing of memory can prevent
3028 breakpoints from being inserted, cause single-stepping to fail, or
3029 even crash your program, if you disable after breakpoints have been
3030 inserted. However, GDB should not crash.
3032 set record memory-query on|off
3033 show record memory-query
3034 Control whether to stop the inferior if memory changes caused
3035 by an instruction cannot be recorded.
3040 The disassemble command now supports "start,+length" form of two arguments.
3044 ** GDB now provides a new directory location, called the python directory,
3045 where Python scripts written for GDB can be installed. The location
3046 of that directory is <data-directory>/python, where <data-directory>
3047 is the GDB data directory. For more details, see section `Scripting
3048 GDB using Python' in the manual.
3050 ** The GDB Python API now has access to breakpoints, symbols, symbol
3051 tables, program spaces, inferiors, threads and frame's code blocks.
3052 Additionally, GDB Parameters can now be created from the API, and
3053 manipulated via set/show in the CLI.
3055 ** New functions gdb.target_charset, gdb.target_wide_charset,
3056 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3058 ** New exception gdb.GdbError.
3060 ** Pretty-printers are now also looked up in the current program space.
3062 ** Pretty-printers can now be individually enabled and disabled.
3064 ** GDB now looks for names of Python scripts to auto-load in a
3065 special section named `.debug_gdb_scripts', in addition to looking
3066 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3068 * Tracepoint actions were unified with breakpoint commands. In particular,
3069 there are no longer differences in "info break" output for breakpoints and
3070 tracepoints and the "commands" command can be used for both tracepoints and
3071 regular breakpoints.
3075 ARM Symbian arm*-*-symbianelf*
3077 * D language support.
3078 GDB now supports debugging programs written in the D programming
3081 * GDB now supports the extended ptrace interface for PowerPC which is
3082 available since Linux kernel version 2.6.34. This automatically enables
3083 any hardware breakpoints and additional hardware watchpoints available in
3084 the processor. The old ptrace interface exposes just one hardware
3085 watchpoint and no hardware breakpoints.
3087 * GDB is now able to use the Data Value Compare (DVC) register available on
3088 embedded PowerPC processors to implement in hardware simple watchpoint
3089 conditions of the form:
3091 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3093 This works in native GDB running on Linux kernels with the extended ptrace
3094 interface mentioned above.
3096 *** Changes in GDB 7.1
3100 ** Namespace Support
3102 GDB now supports importing of namespaces in C++. This enables the
3103 user to inspect variables from imported namespaces. Support for
3104 namepace aliasing has also been added. So, if a namespace is
3105 aliased in the current scope (e.g. namepace C=A; ) the user can
3106 print variables using the alias (e.g. (gdb) print C::x).
3110 All known bugs relating to the printing of virtual base class were
3111 fixed. It is now possible to call overloaded static methods using a
3116 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3117 and reinterpret_cast<> are now handled by the C++ expression parser.
3121 Xilinx MicroBlaze microblaze-*-*
3126 Xilinx MicroBlaze microblaze
3129 * Multi-program debugging.
3131 GDB now has support for multi-program (a.k.a. multi-executable or
3132 multi-exec) debugging. This allows for debugging multiple inferiors
3133 simultaneously each running a different program under the same GDB
3134 session. See "Debugging Multiple Inferiors and Programs" in the
3135 manual for more information. This implied some user visible changes
3136 in the multi-inferior support. For example, "info inferiors" now
3137 lists inferiors that are not running yet or that have exited
3138 already. See also "New commands" and "New options" below.
3140 * New tracing features
3142 GDB's tracepoint facility now includes several new features:
3144 ** Trace state variables
3146 GDB tracepoints now include support for trace state variables, which
3147 are variables managed by the target agent during a tracing
3148 experiment. They are useful for tracepoints that trigger each
3149 other, so for instance one tracepoint can count hits in a variable,
3150 and then a second tracepoint has a condition that is true when the
3151 count reaches a particular value. Trace state variables share the
3152 $-syntax of GDB convenience variables, and can appear in both
3153 tracepoint actions and condition expressions. Use the "tvariable"
3154 command to create, and "info tvariables" to view; see "Trace State
3155 Variables" in the manual for more detail.
3159 GDB now includes an option for defining fast tracepoints, which
3160 targets may implement more efficiently, such as by installing a jump
3161 into the target agent rather than a trap instruction. The resulting
3162 speedup can be by two orders of magnitude or more, although the
3163 tradeoff is that some program locations on some target architectures
3164 might not allow fast tracepoint installation, for instance if the
3165 instruction to be replaced is shorter than the jump. To request a
3166 fast tracepoint, use the "ftrace" command, with syntax identical to
3167 the regular trace command.
3169 ** Disconnected tracing
3171 It is now possible to detach GDB from the target while it is running
3172 a trace experiment, then reconnect later to see how the experiment
3173 is going. In addition, a new variable disconnected-tracing lets you
3174 tell the target agent whether to continue running a trace if the
3175 connection is lost unexpectedly.
3179 GDB now has the ability to save the trace buffer into a file, and
3180 then use that file as a target, similarly to you can do with
3181 corefiles. You can select trace frames, print data that was
3182 collected in them, and use tstatus to display the state of the
3183 tracing run at the moment that it was saved. To create a trace
3184 file, use "tsave <filename>", and to use it, do "target tfile
3187 ** Circular trace buffer
3189 You can ask the target agent to handle the trace buffer as a
3190 circular buffer, discarding the oldest trace frames to make room for
3191 newer ones, by setting circular-trace-buffer to on. This feature may
3192 not be available for all target agents.
3197 The disassemble command, when invoked with two arguments, now requires
3198 the arguments to be comma-separated.
3201 The info variables command now displays variable definitions. Files
3202 which only declare a variable are not shown.
3205 The source command is now capable of sourcing Python scripts.
3206 This feature is dependent on the debugger being build with Python
3209 Related to this enhancement is also the introduction of a new command
3210 "set script-extension" (see below).
3212 * New commands (for set/show, see "New options" below)
3214 record save [<FILENAME>]
3215 Save a file (in core file format) containing the process record
3216 execution log for replay debugging at a later time.
3218 record restore <FILENAME>
3219 Restore the process record execution log that was saved at an
3220 earlier time, for replay debugging.
3222 add-inferior [-copies <N>] [-exec <FILENAME>]
3225 clone-inferior [-copies <N>] [ID]
3226 Make a new inferior ready to execute the same program another
3227 inferior has loaded.
3232 maint info program-spaces
3233 List the program spaces loaded into GDB.
3235 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3236 show remote interrupt-sequence
3237 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3238 as the sequence to the remote target in order to interrupt the execution.
3239 Ctrl-C is a default. Some system prefers BREAK which is high level of
3240 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3241 Magic SysRq g. It is BREAK signal and character 'g'.
3243 set remote interrupt-on-connect [on | off]
3244 show remote interrupt-on-connect
3245 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3246 remote target when gdb connects to it. This is needed when you debug
3249 set remotebreak [on | off]
3251 Deprecated. Use "set/show remote interrupt-sequence" instead.
3253 tvariable $NAME [ = EXP ]
3254 Create or modify a trace state variable.
3257 List trace state variables and their values.
3259 delete tvariable $NAME ...
3260 Delete one or more trace state variables.
3263 Evaluate the given expressions without collecting anything into the
3264 trace buffer. (Valid in tracepoint actions only.)
3266 ftrace FN / FILE:LINE / *ADDR
3267 Define a fast tracepoint at the given function, line, or address.
3269 * New expression syntax
3271 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3272 GDB now parses 0b101010 identically with 42.
3276 set follow-exec-mode new|same
3277 show follow-exec-mode
3278 Control whether GDB reuses the same inferior across an exec call or
3279 creates a new one. This is useful to be able to restart the old
3280 executable after the inferior having done an exec call.
3282 set default-collect EXPR, ...
3283 show default-collect
3284 Define a list of expressions to be collected at each tracepoint.
3285 This is a useful way to ensure essential items are not overlooked,
3286 such as registers or a critical global variable.
3288 set disconnected-tracing
3289 show disconnected-tracing
3290 If set to 1, the target is instructed to continue tracing if it
3291 loses its connection to GDB. If 0, the target is to stop tracing
3294 set circular-trace-buffer
3295 show circular-trace-buffer
3296 If set to on, the target is instructed to use a circular trace buffer
3297 and discard the oldest trace frames instead of stopping the trace due
3298 to a full trace buffer. If set to off, the trace stops when the buffer
3299 fills up. Some targets may not support this.
3301 set script-extension off|soft|strict
3302 show script-extension
3303 If set to "off", the debugger does not perform any script language
3304 recognition, and all sourced files are assumed to be GDB scripts.
3305 If set to "soft" (the default), files are sourced according to
3306 filename extension, falling back to GDB scripts if the first
3308 If set to "strict", files are sourced according to filename extension.
3310 set ada trust-PAD-over-XVS on|off
3311 show ada trust-PAD-over-XVS
3312 If off, activate a workaround against a bug in the debugging information
3313 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3314 the GCC sources for more information about the GNAT encoding and
3315 PAD types in particular). It is always safe to set this option to
3316 off, but this introduces a slight performance penalty. The default
3319 * Python API Improvements
3321 ** GDB provides the new class gdb.LazyString. This is useful in
3322 some pretty-printing cases. The new method gdb.Value.lazy_string
3323 provides a simple way to create objects of this type.
3325 ** The fields returned by gdb.Type.fields now have an
3326 `is_base_class' attribute.
3328 ** The new method gdb.Type.range returns the range of an array type.
3330 ** The new method gdb.parse_and_eval can be used to parse and
3331 evaluate an expression.
3333 * New remote packets
3336 Define a trace state variable.
3339 Get the current value of a trace state variable.
3342 Set desired tracing behavior upon disconnection.
3345 Set the trace buffer to be linear or circular.
3348 Get data about the tracepoints currently in use.
3352 Process record now works correctly with hardware watchpoints.
3354 Multiple bug fixes have been made to the mips-irix port, making it
3355 much more reliable. In particular:
3356 - Debugging threaded applications is now possible again. Previously,
3357 GDB would hang while starting the program, or while waiting for
3358 the program to stop at a breakpoint.
3359 - Attaching to a running process no longer hangs.
3360 - An error occurring while loading a core file has been fixed.
3361 - Changing the value of the PC register now works again. This fixes
3362 problems observed when using the "jump" command, or when calling
3363 a function from GDB, or even when assigning a new value to $pc.
3364 - With the "finish" and "return" commands, the return value for functions
3365 returning a small array is now correctly printed.
3366 - It is now possible to break on shared library code which gets executed
3367 during a shared library init phase (code executed while executing
3368 their .init section). Previously, the breakpoint would have no effect.
3369 - GDB is now able to backtrace through the signal handler for
3370 non-threaded programs.
3372 PIE (Position Independent Executable) programs debugging is now supported.
3373 This includes debugging execution of PIC (Position Independent Code) shared
3374 libraries although for that, it should be possible to run such libraries as an
3377 *** Changes in GDB 7.0
3379 * GDB now has an interface for JIT compilation. Applications that
3380 dynamically generate code can create symbol files in memory and register
3381 them with GDB. For users, the feature should work transparently, and
3382 for JIT developers, the interface is documented in the GDB manual in the
3383 "JIT Compilation Interface" chapter.
3385 * Tracepoints may now be conditional. The syntax is as for
3386 breakpoints; either an "if" clause appended to the "trace" command,
3387 or the "condition" command is available. GDB sends the condition to
3388 the target for evaluation using the same bytecode format as is used
3389 for tracepoint actions.
3391 * The disassemble command now supports: an optional /r modifier, print the
3392 raw instructions in hex as well as in symbolic form, and an optional /m
3393 modifier to print mixed source+assembly.
3395 * Process record and replay
3397 In a architecture environment that supports ``process record and
3398 replay'', ``process record and replay'' target can record a log of
3399 the process execution, and replay it with both forward and reverse
3402 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3403 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3404 set execution-direction {forward|reverse}, for targets that support
3407 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3408 feature is available with a native GDB running on kernel version
3411 * GDB now has support for multi-byte and wide character sets on the
3412 target. Strings whose character type is wchar_t, char16_t, or
3413 char32_t are now correctly printed. GDB supports wide- and unicode-
3414 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3415 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3416 `printf'. This feature requires iconv to work properly; if your
3417 system does not have a working iconv, GDB can use GNU libiconv. See
3418 the installation instructions for more information.
3420 * GDB now supports automatic retrieval of shared library files from
3421 remote targets. To use this feature, specify a system root that begins
3422 with the `remote:' prefix, either via the `set sysroot' command or via
3423 the `--with-sysroot' configure-time option.
3425 * "info sharedlibrary" now takes an optional regex of libraries to show,
3426 and it now reports if a shared library has no debugging information.
3428 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3429 now complete on file names.
3431 * When completing in expressions, gdb will attempt to limit
3432 completions to allowable structure or union fields, where appropriate.
3433 For instance, consider:
3435 # struct example { int f1; double f2; };
3436 # struct example variable;
3439 If the user types TAB at the end of this command line, the available
3440 completions will be "f1" and "f2".
3442 * Inlined functions are now supported. They show up in backtraces, and
3443 the "step", "next", and "finish" commands handle them automatically.
3445 * GDB now supports the token-splicing (##) and stringification (#)
3446 operators when expanding macros. It also supports variable-arity
3449 * GDB now supports inspecting extra signal information, exported by
3450 the new $_siginfo convenience variable. The feature is currently
3451 implemented on linux ARM, i386 and amd64.
3453 * GDB can now display the VFP floating point registers and NEON vector
3454 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3455 can provide these registers (requires Linux 2.6.30 or later). Remote
3456 and simulator targets may also provide them.
3458 * New remote packets
3461 Search memory for a sequence of bytes.
3464 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3465 operation over reliable transport links. Use of this packet is
3466 controlled by the `set remote noack-packet' command.
3469 Kill the process with the specified process ID. Use this in preference
3470 to `k' when multiprocess protocol extensions are supported.
3473 Obtains additional operating system information
3477 Read or write additional signal information.
3479 * Removed remote protocol undocumented extension
3481 An undocumented extension to the remote protocol's `S' stop reply
3482 packet that permited the stub to pass a process id was removed.
3483 Remote servers should use the `T' stop reply packet instead.
3485 * GDB now supports multiple function calling conventions according to the
3486 DWARF-2 DW_AT_calling_convention function attribute.
3488 * The SH target utilizes the aforementioned change to distinguish between gcc
3489 and Renesas calling convention. It also adds the new CLI commands
3490 `set/show sh calling-convention'.
3492 * GDB can now read compressed debug sections, as produced by GNU gold
3493 with the --compress-debug-sections=zlib flag.
3495 * 64-bit core files are now supported on AIX.
3497 * Thread switching is now supported on Tru64.
3499 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3500 which will be allocated using malloc later in program execution.
3502 * The qXfer:libraries:read remote procotol packet now allows passing a
3503 list of section offsets.
3505 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3506 conditions handling signals delivered during attach or thread creation
3507 have also been fixed.
3509 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3510 From the user's standpoint, all unqualified instances of True and False
3511 are treated as the standard definitions, regardless of context.
3513 * GDB now parses C++ symbol and type names more flexibly. For
3516 template<typename T> class C { };
3519 GDB will now correctly handle all of:
3521 ptype C<char const *>
3522 ptype C<char const*>
3523 ptype C<const char *>
3524 ptype C<const char*>
3526 * New features in the GDB remote stub, gdbserver
3528 - The "--wrapper" command-line argument tells gdbserver to use a
3529 wrapper program to launch programs for debugging.
3531 - On PowerPC and S/390 targets, it is now possible to use a single
3532 gdbserver executable to debug both 32-bit and 64-bit programs.
3533 (This requires gdbserver itself to be built as a 64-bit executable.)
3535 - gdbserver uses the new noack protocol mode for TCP connections to
3536 reduce communications latency, if also supported and enabled in GDB.
3538 - Support for the sparc64-linux-gnu target is now included in
3541 - The amd64-linux build of gdbserver now supports debugging both
3542 32-bit and 64-bit programs.
3544 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3545 now support hardware watchpoints, and will use them automatically
3550 GDB now has support for scripting using Python. Whether this is
3551 available is determined at configure time.
3553 New GDB commands can now be written in Python.
3555 * Ada tasking support
3557 Ada tasks can now be inspected in GDB. The following commands have
3561 Print the list of Ada tasks.
3563 Print detailed information about task number N.
3565 Print the task number of the current task.
3567 Switch the context of debugging to task number N.
3569 * Support for user-defined prefixed commands. The "define" command can
3570 add new commands to existing prefixes, e.g. "target".
3572 * Multi-inferior, multi-process debugging.
3574 GDB now has generalized support for multi-inferior debugging. See
3575 "Debugging Multiple Inferiors" in the manual for more information.
3576 Although availability still depends on target support, the command
3577 set is more uniform now. The GNU/Linux specific multi-forks support
3578 has been migrated to this new framework. This implied some user
3579 visible changes; see "New commands" and also "Removed commands"
3582 * Target descriptions can now describe the target OS ABI. See the
3583 "Target Description Format" section in the user manual for more
3586 * Target descriptions can now describe "compatible" architectures
3587 to indicate that the target can execute applications for a different
3588 architecture in addition to those for the main target architecture.
3589 See the "Target Description Format" section in the user manual for
3592 * Multi-architecture debugging.
3594 GDB now includes general supports for debugging applications on
3595 hybrid systems that use more than one single processor architecture
3596 at the same time. Each such hybrid architecture still requires
3597 specific support to be added. The only hybrid architecture supported
3598 in this version of GDB is the Cell Broadband Engine.
3600 * GDB now supports integrated debugging of Cell/B.E. applications that
3601 use both the PPU and SPU architectures. To enable support for hybrid
3602 Cell/B.E. debugging, you need to configure GDB to support both the
3603 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3604 --enable-targets configure option.
3606 * Non-stop mode debugging.
3608 For some targets, GDB now supports an optional mode of operation in
3609 which you can examine stopped threads while other threads continue
3610 to execute freely. This is referred to as non-stop mode, with the
3611 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3612 section in the user manual for more information.
3614 To be able to support remote non-stop debugging, a remote stub needs
3615 to implement the non-stop mode remote protocol extensions, as
3616 described in the "Remote Non-Stop" section of the user manual. The
3617 GDB remote stub, gdbserver, has been adjusted to support these
3618 extensions on linux targets.
3620 * New commands (for set/show, see "New options" below)
3622 catch syscall [NAME(S) | NUMBER(S)]
3623 Catch system calls. Arguments, which should be names of system
3624 calls or their numbers, mean catch only those syscalls. Without
3625 arguments, every syscall will be caught. When the inferior issues
3626 any of the specified syscalls, GDB will stop and announce the system
3627 call, both when it is called and when its call returns. This
3628 feature is currently available with a native GDB running on the
3629 Linux Kernel, under the following architectures: x86, x86_64,
3630 PowerPC and PowerPC64.
3632 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3634 Search memory for a sequence of bytes.
3636 maint set python print-stack
3637 maint show python print-stack
3638 Show a stack trace when an error is encountered in a Python script.
3641 Invoke CODE by passing it to the Python interpreter.
3646 These allow macros to be defined, undefined, and listed
3650 Show operating system information about processes.
3653 List the inferiors currently under GDB's control.
3656 Switch focus to inferior number NUM.
3659 Detach from inferior number NUM.
3662 Kill inferior number NUM.
3666 set spu stop-on-load
3667 show spu stop-on-load
3668 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3670 set spu auto-flush-cache
3671 show spu auto-flush-cache
3672 Control whether to automatically flush the software-managed cache
3673 during Cell/B.E. debugging.
3675 set sh calling-convention
3676 show sh calling-convention
3677 Control the calling convention used when calling SH target functions.
3680 show debug timestamp
3681 Control display of timestamps with GDB debugging output.
3683 set disassemble-next-line
3684 show disassemble-next-line
3685 Control display of disassembled source lines or instructions when
3688 set remote noack-packet
3689 show remote noack-packet
3690 Set/show the use of remote protocol QStartNoAckMode packet. See above
3691 under "New remote packets."
3693 set remote query-attached-packet
3694 show remote query-attached-packet
3695 Control use of remote protocol `qAttached' (query-attached) packet.
3697 set remote read-siginfo-object
3698 show remote read-siginfo-object
3699 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3702 set remote write-siginfo-object
3703 show remote write-siginfo-object
3704 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3707 set remote reverse-continue
3708 show remote reverse-continue
3709 Control use of remote protocol 'bc' (reverse-continue) packet.
3711 set remote reverse-step
3712 show remote reverse-step
3713 Control use of remote protocol 'bs' (reverse-step) packet.
3715 set displaced-stepping
3716 show displaced-stepping
3717 Control displaced stepping mode. Displaced stepping is a way to
3718 single-step over breakpoints without removing them from the debuggee.
3719 Also known as "out-of-line single-stepping".
3722 show debug displaced
3723 Control display of debugging info for displaced stepping.
3725 maint set internal-error
3726 maint show internal-error
3727 Control what GDB does when an internal error is detected.
3729 maint set internal-warning
3730 maint show internal-warning
3731 Control what GDB does when an internal warning is detected.
3736 Use a wrapper program to launch programs for debugging.
3738 set multiple-symbols (all|ask|cancel)
3739 show multiple-symbols
3740 The value of this variable can be changed to adjust the debugger behavior
3741 when an expression or a breakpoint location contains an ambiguous symbol
3742 name (an overloaded function name, for instance).
3744 set breakpoint always-inserted
3745 show breakpoint always-inserted
3746 Keep breakpoints always inserted in the target, as opposed to inserting
3747 them when resuming the target, and removing them when the target stops.
3748 This option can improve debugger performance on slow remote targets.
3750 set arm fallback-mode (arm|thumb|auto)
3751 show arm fallback-mode
3752 set arm force-mode (arm|thumb|auto)
3754 These commands control how ARM GDB determines whether instructions
3755 are ARM or Thumb. The default for both settings is auto, which uses
3756 the current CPSR value for instructions without symbols; previous
3757 versions of GDB behaved as if "set arm fallback-mode arm".
3759 set disable-randomization
3760 show disable-randomization
3761 Standalone programs run with the virtual address space randomization enabled
3762 by default on some platforms. This option keeps the addresses stable across
3763 multiple debugging sessions.
3767 Control whether other threads are stopped or not when some thread hits
3772 Requests that asynchronous execution is enabled in the target, if available.
3773 In this case, it's possible to resume target in the background, and interact
3774 with GDB while the target is running. "show target-async" displays the
3775 current state of asynchronous execution of the target.
3777 set target-wide-charset
3778 show target-wide-charset
3779 The target-wide-charset is the name of the character set that GDB
3780 uses when printing characters whose type is wchar_t.
3782 set tcp auto-retry (on|off)
3784 set tcp connect-timeout
3785 show tcp connect-timeout
3786 These commands allow GDB to retry failed TCP connections to a remote stub
3787 with a specified timeout period; this is useful if the stub is launched
3788 in parallel with GDB but may not be ready to accept connections immediately.
3790 set libthread-db-search-path
3791 show libthread-db-search-path
3792 Control list of directories which GDB will search for appropriate
3795 set schedule-multiple (on|off)
3796 show schedule-multiple
3797 Allow GDB to resume all threads of all processes or only threads of
3798 the current process.
3802 Use more aggressive caching for accesses to the stack. This improves
3803 performance of remote debugging (particularly backtraces) without
3804 affecting correctness.
3806 set interactive-mode (on|off|auto)
3807 show interactive-mode
3808 Control whether GDB runs in interactive mode (on) or not (off).
3809 When in interactive mode, GDB waits for the user to answer all
3810 queries. Otherwise, GDB does not wait and assumes the default
3811 answer. When set to auto (the default), GDB determines which
3812 mode to use based on the stdin settings.
3817 For program forks, this is replaced by the new more generic `info
3818 inferiors' command. To list checkpoints, you can still use the
3819 `info checkpoints' command, which was an alias for the `info forks'
3823 Replaced by the new `inferior' command. To switch between
3824 checkpoints, you can still use the `restart' command, which was an
3825 alias for the `fork' command.
3828 This is removed, since some targets don't have a notion of
3829 processes. To switch between processes, you can still use the
3830 `inferior' command using GDB's own inferior number.
3833 For program forks, this is replaced by the new more generic `kill
3834 inferior' command. To delete a checkpoint, you can still use the
3835 `delete checkpoint' command, which was an alias for the `delete
3839 For program forks, this is replaced by the new more generic `detach
3840 inferior' command. To detach a checkpoint, you can still use the
3841 `detach checkpoint' command, which was an alias for the `detach
3844 * New native configurations
3846 x86/x86_64 Darwin i[34567]86-*-darwin*
3848 x86_64 MinGW x86_64-*-mingw*
3852 Lattice Mico32 lm32-*
3853 x86 DICOS i[34567]86-*-dicos*
3854 x86_64 DICOS x86_64-*-dicos*
3857 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3858 (mingw32ce) debugging.
3864 These commands were actually not implemented on any target.
3866 *** Changes in GDB 6.8
3868 * New native configurations
3870 NetBSD/hppa hppa*-*netbsd*
3871 Xtensa GNU/Linux xtensa*-*-linux*
3875 NetBSD/hppa hppa*-*-netbsd*
3876 Xtensa GNU/Lunux xtensa*-*-linux*
3878 * Change in command line behavior -- corefiles vs. process ids.
3880 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3881 attaching to process NUMBER fails, GDB no longer attempts to open a
3882 core file named NUMBER. Attaching to a program using the -c option
3883 is no longer supported. Instead, use the '-p' or '--pid' options.
3885 * GDB can now be built as a native debugger for debugging Windows x86
3886 (mingw32) Portable Executable (PE) programs.
3888 * Pending breakpoints no longer change their number when their address
3891 * GDB now supports breakpoints with multiple locations,
3892 including breakpoints on C++ constructors, inside C++ templates,
3893 and in inlined functions.
3895 * GDB's ability to debug optimized code has been improved. GDB more
3896 accurately identifies function bodies and lexical blocks that occupy
3897 more than one contiguous range of addresses.
3899 * Target descriptions can now describe registers for PowerPC.
3901 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3902 registers on PowerPC targets.
3904 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3905 targets even when the libthread_db library is not available.
3907 * The GDB remote stub, gdbserver, now supports the new file transfer
3908 commands (remote put, remote get, and remote delete).
3910 * The GDB remote stub, gdbserver, now supports run and attach in
3911 extended-remote mode.
3913 * hppa*64*-*-hpux11* target broken
3914 The debugger is unable to start a program and fails with the following
3915 error: "Error trying to get information about dynamic linker".
3916 The gdb-6.7 release is also affected.
3918 * GDB now supports the --enable-targets= configure option to allow
3919 building a single GDB executable that supports multiple remote
3920 target architectures.
3922 * GDB now supports debugging C and C++ programs which use the
3923 Decimal Floating Point extension. In addition, the PowerPC target
3924 now has a set of pseudo-registers to inspect decimal float values
3925 stored in two consecutive float registers.
3927 * The -break-insert MI command can optionally create pending
3930 * Improved support for debugging Ada
3931 Many improvements to the Ada language support have been made. These
3933 - Better support for Ada2005 interface types
3934 - Improved handling of arrays and slices in general
3935 - Better support for Taft-amendment types
3936 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3938 - Improved command completion in Ada
3941 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3946 set print frame-arguments (all|scalars|none)
3947 show print frame-arguments
3948 The value of this variable can be changed to control which argument
3949 values should be printed by the debugger when displaying a frame.
3954 Transfer files to and from a remote target, and delete remote files.
3961 Transfer files to and from a remote target, and delete remote files.
3963 * New remote packets
3970 Open, close, read, write, and delete files on the remote system.
3973 Attach to an existing process on the remote system, in extended-remote
3977 Run a new process on the remote system, in extended-remote mode.
3979 *** Changes in GDB 6.7
3981 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3982 bfd, libiberty and opcodes, as revealed by static analysis donated by
3983 Coverity, Inc. (http://scan.coverity.com).
3985 * When looking up multiply-defined global symbols, GDB will now prefer the
3986 symbol definition in the current shared library if it was built using the
3987 -Bsymbolic linker option.
3989 * When the Text User Interface (TUI) is not configured, GDB will now
3990 recognize the -tui command-line option and print a message that the TUI
3993 * The GDB remote stub, gdbserver, now has lower overhead for high
3994 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3996 * GDB for MIPS targets now autodetects whether a remote target provides
3997 32-bit or 64-bit register values.
3999 * Support for C++ member pointers has been improved.
4001 * GDB now understands XML target descriptions, which specify the
4002 target's overall architecture. GDB can read a description from
4003 a local file or over the remote serial protocol.
4005 * Vectors of single-byte data use a new integer type which is not
4006 automatically displayed as character or string data.
4008 * The /s format now works with the print command. It displays
4009 arrays of single-byte integers and pointers to single-byte integers
4012 * Target descriptions can now describe target-specific registers,
4013 for architectures which have implemented the support (currently
4014 only ARM, M68K, and MIPS).
4016 * GDB and the GDB remote stub, gdbserver, now support the XScale
4019 * The GDB remote stub, gdbserver, has been updated to support
4020 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4021 has been rewritten to use the standard GDB remote protocol.
4023 * GDB can now step into C++ functions which are called through thunks.
4025 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4027 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4028 layout. It also supports a TextSeg= and DataSeg= response when only
4029 segment base addresses (rather than offsets) are available.
4031 * The /i format now outputs any trailing branch delay slot instructions
4032 immediately following the last instruction within the count specified.
4034 * The GDB remote protocol "T" stop reply packet now supports a
4035 "library" response. Combined with the new "qXfer:libraries:read"
4036 packet, this response allows GDB to debug shared libraries on targets
4037 where the operating system manages the list of loaded libraries (e.g.
4038 Windows and SymbianOS).
4040 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4041 (DLLs) on Windows and Windows CE targets.
4043 * GDB now supports a faster verification that a .debug file matches its binary
4044 according to its build-id signature, if the signature is present.
4050 Enable or disable hardware flow control (RTS/CTS) on the serial port
4051 when debugging using remote targets.
4053 set mem inaccessible-by-default
4054 show mem inaccessible-by-default
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 prevents GDB from accessing memory outside the memory map. This
4058 is useful for targets with memory mapped registers or which react
4059 badly to accesses of unmapped address space.
4061 set breakpoint auto-hw
4062 show breakpoint auto-hw
4063 If the target supplies a memory map, for instance via the remote
4064 protocol's "qXfer:memory-map:read" packet, setting this variable
4065 lets GDB use hardware breakpoints automatically for memory regions
4066 where it can not use software breakpoints. This covers both the
4067 "break" command and internal breakpoints used for other commands
4068 including "next" and "finish".
4071 catch exception unhandled
4072 Stop the program execution when Ada exceptions are raised.
4075 Stop the program execution when an Ada assertion failed.
4079 Set an alternate system root for target files. This is a more
4080 general version of "set solib-absolute-prefix", which is now
4081 an alias to "set sysroot".
4084 Provide extended SPU facility status information. This set of
4085 commands is available only when debugging the Cell/B.E. SPU
4088 * New native configurations
4090 OpenBSD/sh sh*-*openbsd*
4093 unset tdesc filename
4095 Use the specified local file as an XML target description, and do
4096 not query the target for its built-in description.
4100 OpenBSD/sh sh*-*-openbsd*
4101 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4102 Toshiba Media Processor mep-elf
4104 * New remote packets
4107 Ignore the specified signals; pass them directly to the debugged program
4108 without stopping other threads or reporting them to GDB.
4110 qXfer:features:read:
4111 Read an XML target description from the target, which describes its
4116 Read or write contents of an spufs file on the target system. These
4117 packets are available only on the Cell/B.E. SPU architecture.
4119 qXfer:libraries:read:
4120 Report the loaded shared libraries. Combined with new "T" packet
4121 response, this packet allows GDB to debug shared libraries on
4122 targets where the operating system manages the list of loaded
4123 libraries (e.g. Windows and SymbianOS).
4127 Support for these obsolete configurations has been removed.
4135 i[34567]86-*-lynxos*
4136 i[34567]86-*-netware*
4137 i[34567]86-*-sco3.2v5*
4138 i[34567]86-*-sco3.2v4*
4140 i[34567]86-*-sysv4.2*
4143 i[34567]86-*-unixware2*
4144 i[34567]86-*-unixware*
4153 * Other removed features
4160 Various m68k-only ROM monitors.
4167 Various Renesas ROM monitors and debugging interfaces for SH and
4172 Support for a Macraigor serial interface to on-chip debugging.
4173 GDB does not directly support the newer parallel or USB
4178 A debug information format. The predecessor to DWARF 2 and
4179 DWARF 3, which are still supported.
4181 Support for the HP aCC compiler on HP-UX/PA-RISC
4183 SOM-encapsulated symbolic debugging information, automatic
4184 invocation of pxdb, and the aCC custom C++ ABI. This does not
4185 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4186 with aCC can still be debugged on an assembly level.
4188 MIPS ".pdr" sections
4190 A MIPS-specific format used to describe stack frame layout
4191 in debugging information.
4195 GDB could work with an older version of Guile to debug
4196 the interpreter and Scheme programs running in it.
4198 set mips stack-arg-size
4199 set mips saved-gpreg-size
4201 Use "set mips abi" to control parameter passing for MIPS.
4203 *** Changes in GDB 6.6
4208 Cell Broadband Engine SPU spu-elf
4210 * GDB can now be configured as a cross-debugger targeting native Windows
4211 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4212 running on a Windows system over TCP/IP to debug Windows programs.
4214 * The GDB remote stub, gdbserver, has been updated to support Windows and
4215 Cygwin debugging. Both single-threaded and multi-threaded programs are
4218 * The "set trust-readonly-sections" command works again. This command was
4219 broken in GDB 6.3, 6.4, and 6.5.
4221 * The "load" command now supports writing to flash memory, if the remote
4222 stub provides the required support.
4224 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4225 longer requires symbolic debug information (e.g. DWARF-2).
4230 unset substitute-path
4231 show substitute-path
4232 Manage a list of substitution rules that GDB uses to rewrite the name
4233 of the directories where the sources are located. This can be useful
4234 for instance when the sources were moved to a different location
4235 between compilation and debugging.
4239 Print each CLI command as it is executed. Each command is prefixed with
4240 a number of `+' symbols representing the nesting depth.
4241 The source command now has a `-v' option to enable the same feature.
4245 The ARM Demon monitor support (RDP protocol, "target rdp").
4247 Kernel Object Display, an embedded debugging feature which only worked with
4248 an obsolete version of Cisco IOS.
4250 The 'set download-write-size' and 'show download-write-size' commands.
4252 * New remote packets
4255 Tell a stub about GDB client features, and request remote target features.
4256 The first feature implemented is PacketSize, which allows the target to
4257 specify the size of packets it can handle - to minimize the number of
4258 packets required and improve performance when connected to a remote
4262 Fetch an OS auxilliary vector from the remote stub. This packet is a
4263 more efficient replacement for qPart:auxv:read.
4265 qXfer:memory-map:read:
4266 Fetch a memory map from the remote stub, including information about
4267 RAM, ROM, and flash memory devices.
4272 Erase and program a flash memory device.
4274 * Removed remote packets
4277 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4278 used it, and only gdbserver implemented it.
4280 *** Changes in GDB 6.5
4284 Renesas M32C/M16C m32c-elf
4286 Morpho Technologies ms1 ms1-elf
4290 init-if-undefined Initialize a convenience variable, but
4291 only if it doesn't already have a value.
4293 The following commands are presently only implemented for native GNU/Linux:
4295 checkpoint Save a snapshot of the program state.
4297 restart <n> Return the program state to a
4298 previously saved state.
4300 info checkpoints List currently saved checkpoints.
4302 delete-checkpoint <n> Delete a previously saved checkpoint.
4304 set|show detach-on-fork Tell gdb whether to detach from a newly
4305 forked process, or to keep debugging it.
4307 info forks List forks of the user program that
4308 are available to be debugged.
4310 fork <n> Switch to debugging one of several
4311 forks of the user program that are
4312 available to be debugged.
4314 delete-fork <n> Delete a fork from the list of forks
4315 that are available to be debugged (and
4316 kill the forked process).
4318 detach-fork <n> Delete a fork from the list of forks
4319 that are available to be debugged (and
4320 allow the process to continue).
4324 Morpho Technologies ms2 ms1-elf
4326 * Improved Windows host support
4328 GDB now builds as a cross debugger hosted on i686-mingw32, including
4329 native console support, and remote communications using either
4330 network sockets or serial ports.
4332 * Improved Modula-2 language support
4334 GDB can now print most types in the Modula-2 syntax. This includes:
4335 basic types, set types, record types, enumerated types, range types,
4336 pointer types and ARRAY types. Procedure var parameters are correctly
4337 printed and hexadecimal addresses and character constants are also
4338 written in the Modula-2 syntax. Best results can be obtained by using
4339 GNU Modula-2 together with the -gdwarf-2 command line option.
4343 The ARM rdi-share module.
4345 The Netware NLM debug server.
4347 *** Changes in GDB 6.4
4349 * New native configurations
4351 OpenBSD/arm arm*-*-openbsd*
4352 OpenBSD/mips64 mips64-*-openbsd*
4356 Morpho Technologies ms1 ms1-elf
4358 * New command line options
4360 --batch-silent As for --batch, but totally silent.
4361 --return-child-result The debugger will exist with the same value
4362 the child (debugged) program exited with.
4363 --eval-command COMMAND, -ex COMMAND
4364 Execute a single GDB CLI command. This may be
4365 specified multiple times and in conjunction
4366 with the --command (-x) option.
4368 * Deprecated commands removed
4370 The following commands, that were deprecated in 2000, have been
4374 set|show arm disassembly-flavor set|show arm disassembler
4375 othernames set arm disassembler
4376 set|show remotedebug set|show debug remote
4377 set|show archdebug set|show debug arch
4378 set|show eventdebug set|show debug event
4381 * New BSD user-level threads support
4383 It is now possible to debug programs using the user-level threads
4384 library on OpenBSD and FreeBSD. Currently supported (target)
4387 FreeBSD/amd64 x86_64-*-freebsd*
4388 FreeBSD/i386 i386-*-freebsd*
4389 OpenBSD/i386 i386-*-openbsd*
4391 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4392 are not yet supported.
4394 * New support for Matsushita MN10300 w/sim added
4395 (Work in progress). mn10300-elf.
4397 * REMOVED configurations and files
4399 VxWorks and the XDR protocol *-*-vxworks
4400 Motorola MCORE mcore-*-*
4401 National Semiconductor NS32000 ns32k-*-*
4403 * New "set print array-indexes" command
4405 After turning this setting "on", GDB prints the index of each element
4406 when displaying arrays. The default is "off" to preserve the previous
4409 * VAX floating point support
4411 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4413 * User-defined command support
4415 In addition to using $arg0..$arg9 for argument passing, it is now possible
4416 to use $argc to determine now many arguments have been passed. See the
4417 section on user-defined commands in the user manual for more information.
4419 *** Changes in GDB 6.3:
4421 * New command line option
4423 GDB now accepts -l followed by a number to set the timeout for remote
4426 * GDB works with GCC -feliminate-dwarf2-dups
4428 GDB now supports a more compact representation of DWARF-2 debug
4429 information using DW_FORM_ref_addr references. These are produced
4430 by GCC with the option -feliminate-dwarf2-dups and also by some
4431 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4432 to use -feliminate-dwarf2-dups.
4434 * Internationalization
4436 When supported by the host system, GDB will be built with
4437 internationalization (libintl). The task of marking up the sources is
4438 continued, we're looking forward to our first translation.
4442 Initial support for debugging programs compiled with the GNAT
4443 implementation of the Ada programming language has been integrated
4444 into GDB. In this release, support is limited to expression evaluation.
4446 * New native configurations
4448 GNU/Linux/m32r m32r-*-linux-gnu
4452 GDB's remote protocol now includes support for the 'p' packet. This
4453 packet is used to fetch individual registers from a remote inferior.
4455 * END-OF-LIFE registers[] compatibility module
4457 GDB's internal register infrastructure has been completely rewritten.
4458 The new infrastructure making possible the implementation of key new
4459 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4462 GDB 6.3 will be the last release to include the the registers[]
4463 compatibility module that allowed out-of-date configurations to
4464 continue to work. This change directly impacts the following
4474 powerpc bdm protocol
4476 Unless there is activity to revive these configurations, they will be
4477 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4479 * OBSOLETE configurations and files
4481 Configurations that have been declared obsolete in this release have
4482 been commented out. Unless there is activity to revive these
4483 configurations, the next release of GDB will have their sources
4484 permanently REMOVED.
4493 *** Changes in GDB 6.2.1:
4495 * MIPS `break main; run' gave an heuristic-fence-post warning
4497 When attempting to run even a simple program, a warning about
4498 heuristic-fence-post being hit would be reported. This problem has
4501 * MIPS IRIX 'long double' crashed GDB
4503 When examining a long double variable, GDB would get a segmentation
4504 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4505 IRIX long double values).
4509 A bug in the VAX stack code was causing problems with the "next"
4510 command. This problem has been fixed.
4512 *** Changes in GDB 6.2:
4514 * Fix for ``many threads''
4516 On GNU/Linux systems that use the NPTL threads library, a program
4517 rapidly creating and deleting threads would confuse GDB leading to the
4520 ptrace: No such process.
4521 thread_db_get_info: cannot get thread info: generic error
4523 This problem has been fixed.
4525 * "-async" and "-noasync" options removed.
4527 Support for the broken "-noasync" option has been removed (it caused
4530 * New ``start'' command.
4532 This command runs the program until the begining of the main procedure.
4534 * New BSD Kernel Data Access Library (libkvm) interface
4536 Using ``target kvm'' it is now possible to debug kernel core dumps and
4537 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4538 platforms. Currently supported (native-only) configurations are:
4540 FreeBSD/amd64 x86_64-*-freebsd*
4541 FreeBSD/i386 i?86-*-freebsd*
4542 NetBSD/i386 i?86-*-netbsd*
4543 NetBSD/m68k m68*-*-netbsd*
4544 NetBSD/sparc sparc-*-netbsd*
4545 OpenBSD/amd64 x86_64-*-openbsd*
4546 OpenBSD/i386 i?86-*-openbsd*
4547 OpenBSD/m68k m68*-openbsd*
4548 OpenBSD/sparc sparc-*-openbsd*
4550 * Signal trampoline code overhauled
4552 Many generic problems with GDB's signal handling code have been fixed.
4553 These include: backtraces through non-contiguous stacks; recognition
4554 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4555 call; backtrace through a signal trampoline; step into and out of
4556 signal handlers; and single-stepping in the signal trampoline.
4558 Please note that kernel bugs are a limiting factor here. These
4559 features have been shown to work on an s390 GNU/Linux system that
4560 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4562 * Cygwin support for DWARF 2 added.
4564 * New native configurations
4566 GNU/Linux/hppa hppa*-*-linux*
4567 OpenBSD/hppa hppa*-*-openbsd*
4568 OpenBSD/m68k m68*-*-openbsd*
4569 OpenBSD/m88k m88*-*-openbsd*
4570 OpenBSD/powerpc powerpc-*-openbsd*
4571 NetBSD/vax vax-*-netbsd*
4572 OpenBSD/vax vax-*-openbsd*
4574 * END-OF-LIFE frame compatibility module
4576 GDB's internal frame infrastructure has been completely rewritten.
4577 The new infrastructure making it possible to support key new features
4578 including DWARF 2 Call Frame Information. To aid in the task of
4579 migrating old configurations to this new infrastructure, a
4580 compatibility module, that allowed old configurations to continue to
4581 work, was also included.
4583 GDB 6.2 will be the last release to include this frame compatibility
4584 module. This change directly impacts the following configurations:
4594 Unless there is activity to revive these configurations, they will be
4595 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4597 * REMOVED configurations and files
4599 Sun 3, running SunOS 3 m68*-*-sunos3*
4600 Sun 3, running SunOS 4 m68*-*-sunos4*
4601 Sun 2, running SunOS 3 m68000-*-sunos3*
4602 Sun 2, running SunOS 4 m68000-*-sunos4*
4603 Motorola 680x0 running LynxOS m68*-*-lynxos*
4604 AT&T 3b1/Unix pc m68*-att-*
4605 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4606 decstation mips-dec-* mips-little-*
4607 riscos mips-*-riscos* mips-*-sysv*
4608 sonymips mips-sony-*
4609 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4611 *** Changes in GDB 6.1.1:
4613 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4615 The TUI (Text-mode User Interface) is now built as part of a default
4616 GDB configuration. It is enabled by either selecting the TUI with the
4617 command line option "-i=tui" or by running the separate "gdbtui"
4618 program. For more information on the TUI, see the manual "Debugging
4621 * Pending breakpoint support (also included in GDB 6.1)
4623 Support has been added to allow you to specify breakpoints in shared
4624 libraries that have not yet been loaded. If a breakpoint location
4625 cannot be found, and the "breakpoint pending" option is set to auto,
4626 GDB queries you if you wish to make the breakpoint pending on a future
4627 shared-library load. If and when GDB resolves the breakpoint symbol,
4628 the pending breakpoint is removed as one or more regular breakpoints
4631 Pending breakpoints are very useful for GCJ Java debugging.
4633 * Fixed ISO-C build problems
4635 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4636 non ISO-C code that stopped them being built using a more strict ISO-C
4637 compiler (e.g., IBM's C compiler).
4639 * Fixed build problem on IRIX 5
4641 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4642 wasn't able to compile compile on an IRIX 5 system.
4644 * Added execute permission to gdb/gdbserver/configure
4646 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4647 permission. This bug would cause configure to fail on a number of
4648 systems (Solaris, IRIX). Ref: server/519.
4650 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4652 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4653 has been updated to use constant array sizes.
4655 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4657 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4658 its generated DWARF Call Frame Info. This encoding was causing GDB to
4659 panic, that panic has been fixed. Ref: gdb/1628.
4661 * Fixed a problem when examining parameters in shared library code.
4663 When examining parameters in optimized shared library code generated
4664 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4665 not available''. GDB now correctly displays the variable's value.
4667 *** Changes in GDB 6.1:
4669 * Removed --with-mmalloc
4671 Support for the mmalloc memory manager has been removed, as it
4672 conflicted with the internal gdb byte cache.
4674 * Changes in AMD64 configurations
4676 The AMD64 target now includes the %cs and %ss registers. As a result
4677 the AMD64 remote protocol has changed; this affects the floating-point
4678 and SSE registers. If you rely on those registers for your debugging,
4679 you should upgrade gdbserver on the remote side.
4681 * Revised SPARC target
4683 The SPARC target has been completely revised, incorporating the
4684 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4685 support for LynxOS and SunOS 4 has been dropped. Calling functions
4686 from within GDB on operating systems with a non-executable stack
4687 (Solaris, OpenBSD) now works.
4691 GDB has a new C++ demangler which does a better job on the mangled
4692 names generated by current versions of g++. It also runs faster, so
4693 with this and other changes gdb should now start faster on large C++
4696 * DWARF 2 Location Expressions
4698 GDB support for location expressions has been extended to support function
4699 arguments and frame bases. Older versions of GDB could crash when they
4702 * C++ nested types and namespaces
4704 GDB's support for nested types and namespaces in C++ has been
4705 improved, especially if you use the DWARF 2 debugging format. (This
4706 is the default for recent versions of GCC on most platforms.)
4707 Specifically, if you have a class "Inner" defined within a class or
4708 namespace "Outer", then GDB realizes that the class's name is
4709 "Outer::Inner", not simply "Inner". This should greatly reduce the
4710 frequency of complaints about not finding RTTI symbols. In addition,
4711 if you are stopped at inside of a function defined within a namespace,
4712 GDB modifies its name lookup accordingly.
4714 * New native configurations
4716 NetBSD/amd64 x86_64-*-netbsd*
4717 OpenBSD/amd64 x86_64-*-openbsd*
4718 OpenBSD/alpha alpha*-*-openbsd*
4719 OpenBSD/sparc sparc-*-openbsd*
4720 OpenBSD/sparc64 sparc64-*-openbsd*
4722 * New debugging protocols
4724 M32R with SDI protocol m32r-*-elf*
4726 * "set prompt-escape-char" command deleted.
4728 The command "set prompt-escape-char" has been deleted. This command,
4729 and its very obscure effet on GDB's prompt, was never documented,
4730 tested, nor mentioned in the NEWS file.
4732 * OBSOLETE configurations and files
4734 Configurations that have been declared obsolete in this release have
4735 been commented out. Unless there is activity to revive these
4736 configurations, the next release of GDB will have their sources
4737 permanently REMOVED.
4739 Sun 3, running SunOS 3 m68*-*-sunos3*
4740 Sun 3, running SunOS 4 m68*-*-sunos4*
4741 Sun 2, running SunOS 3 m68000-*-sunos3*
4742 Sun 2, running SunOS 4 m68000-*-sunos4*
4743 Motorola 680x0 running LynxOS m68*-*-lynxos*
4744 AT&T 3b1/Unix pc m68*-att-*
4745 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4746 decstation mips-dec-* mips-little-*
4747 riscos mips-*-riscos* mips-*-sysv*
4748 sonymips mips-sony-*
4749 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4751 * REMOVED configurations and files
4753 SGI Irix-4.x mips-sgi-irix4 or iris4
4754 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4755 Z8000 simulator z8k-zilog-none or z8ksim
4756 Matsushita MN10200 w/simulator mn10200-*-*
4757 H8/500 simulator h8500-hitachi-hms or h8500hms
4758 HP/PA running BSD hppa*-*-bsd*
4759 HP/PA running OSF/1 hppa*-*-osf*
4760 HP/PA Pro target hppa*-*-pro*
4761 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4762 386BSD i[3456]86-*-bsd*
4763 Sequent family i[3456]86-sequent-sysv4*
4764 i[3456]86-sequent-sysv*
4765 i[3456]86-sequent-bsd*
4766 SPARC running LynxOS sparc-*-lynxos*
4767 SPARC running SunOS 4 sparc-*-sunos4*
4768 Tsqware Sparclet sparclet-*-*
4769 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4771 *** Changes in GDB 6.0:
4775 Support for debugging the Objective-C programming language has been
4776 integrated into GDB.
4778 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4780 DWARF 2's Call Frame Information makes available compiler generated
4781 information that more exactly describes the program's run-time stack.
4782 By using this information, GDB is able to provide more robust stack
4785 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4786 have been updated to use a new backtrace mechanism which includes
4787 DWARF 2 CFI support.
4791 GDB's remote protocol has been extended to include support for hosted
4792 file I/O (where the remote target uses GDB's file system). See GDB's
4793 remote protocol documentation for details.
4795 * All targets using the new architecture framework.
4797 All of GDB's targets have been updated to use the new internal
4798 architecture framework. The way is now open for future GDB releases
4799 to include cross-architecture native debugging support (i386 on amd64,
4802 * GNU/Linux's Thread Local Storage (TLS)
4804 GDB now includes support for for the GNU/Linux implementation of
4805 per-thread variables.
4807 * GNU/Linux's Native POSIX Thread Library (NPTL)
4809 GDB's thread code has been updated to work with either the new
4810 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4812 * Separate debug info.
4814 GDB, in conjunction with BINUTILS, now supports a mechanism for
4815 automatically loading debug information from a separate file. Instead
4816 of shipping full debug and non-debug versions of system libraries,
4817 system integrators can now instead ship just the stripped libraries
4818 and optional debug files.
4820 * DWARF 2 Location Expressions
4822 DWARF 2 Location Expressions allow the compiler to more completely
4823 describe the location of variables (even in optimized code) to the
4826 GDB now includes preliminary support for location expressions (support
4827 for DW_OP_piece is still missing).
4831 A number of long standing bugs that caused GDB to die while starting a
4832 Java application have been fixed. GDB's Java support is now
4833 considered "useable".
4835 * GNU/Linux support for fork, vfork, and exec.
4837 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4838 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4841 * GDB supports logging output to a file
4843 There are two new commands, "set logging" and "show logging", which can be
4844 used to capture GDB's output to a file.
4846 * The meaning of "detach" has changed for gdbserver
4848 The "detach" command will now resume the application, as documented. To
4849 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4852 * d10v, m68hc11 `regs' command deprecated
4854 The `info registers' command has been updated so that it displays the
4855 registers using a format identical to the old `regs' command.
4859 A new command, "maint set profile on/off", has been added. This command can
4860 be used to enable or disable profiling while running GDB, to profile a
4861 session or a set of commands. In addition there is a new configure switch,
4862 "--enable-profiling", which will cause GDB to be compiled with profiling
4863 data, for more informative profiling results.
4865 * Default MI syntax changed to "mi2".
4867 The default MI (machine interface) syntax, enabled by the command line
4868 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4869 "mi1", can be enabled by specifying the option "-i=mi1".
4871 Support for the original "mi0" syntax (included in GDB 5.0) has been
4874 Fix for gdb/192: removed extraneous space when displaying frame level.
4875 Fix for gdb/672: update changelist is now output in mi list format.
4876 Fix for gdb/702: a -var-assign that updates the value now shows up
4877 in a subsequent -var-update.
4879 * New native configurations.
4881 FreeBSD/amd64 x86_64-*-freebsd*
4883 * Multi-arched targets.
4885 HP/PA HPUX11 hppa*-*-hpux*
4886 Renesas M32R/D w/simulator m32r-*-elf*
4888 * OBSOLETE configurations and files
4890 Configurations that have been declared obsolete in this release have
4891 been commented out. Unless there is activity to revive these
4892 configurations, the next release of GDB will have their sources
4893 permanently REMOVED.
4895 Z8000 simulator z8k-zilog-none or z8ksim
4896 Matsushita MN10200 w/simulator mn10200-*-*
4897 H8/500 simulator h8500-hitachi-hms or h8500hms
4898 HP/PA running BSD hppa*-*-bsd*
4899 HP/PA running OSF/1 hppa*-*-osf*
4900 HP/PA Pro target hppa*-*-pro*
4901 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4902 Sequent family i[3456]86-sequent-sysv4*
4903 i[3456]86-sequent-sysv*
4904 i[3456]86-sequent-bsd*
4905 Tsqware Sparclet sparclet-*-*
4906 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4908 * REMOVED configurations and files
4911 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4912 IBM AIX PS/2 i[3456]86-*-aix
4913 i386 running Mach 3.0 i[3456]86-*-mach3*
4914 i386 running Mach i[3456]86-*-mach*
4915 i386 running OSF/1 i[3456]86-*osf1mk*
4916 HP/Apollo 68k Family m68*-apollo*-sysv*,
4918 m68*-hp-bsd*, m68*-hp-hpux*
4919 Argonaut Risc Chip (ARC) arc-*-*
4920 Mitsubishi D30V d30v-*-*
4921 Fujitsu FR30 fr30-*-elf*
4922 OS/9000 i[34]86-*-os9k
4923 I960 with MON960 i960-*-coff
4925 * MIPS $fp behavior changed
4927 The convenience variable $fp, for the MIPS, now consistently returns
4928 the address of the current frame's base. Previously, depending on the
4929 context, $fp could refer to either $sp or the current frame's base
4930 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4931 The GNU Source-Level Debugger''.
4933 *** Changes in GDB 5.3:
4935 * GNU/Linux shared library multi-threaded performance improved.
4937 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4938 `/proc', in preference to `ptrace' for memory reads. This may result
4939 in an improvement in the start-up time of multi-threaded, shared
4940 library applications when run under GDB. One GDB user writes: ``loads
4941 shared libs like mad''.
4943 * ``gdbserver'' now supports multi-threaded applications on some targets
4945 Support for debugging multi-threaded applications which use
4946 the GNU/Linux LinuxThreads package has been added for
4947 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4948 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4950 * GDB now supports C/C++ preprocessor macros.
4952 GDB now expands preprocessor macro invocations in C/C++ expressions,
4953 and provides various commands for showing macro definitions and how
4956 The new command `macro expand EXPRESSION' expands any macro
4957 invocations in expression, and shows the result.
4959 The new command `show macro MACRO-NAME' shows the definition of the
4960 macro named MACRO-NAME, and where it was defined.
4962 Most compilers don't include information about macros in the debugging
4963 information by default. In GCC 3.1, for example, you need to compile
4964 your program with the options `-gdwarf-2 -g3'. If the macro
4965 information is present in the executable, GDB will read it.
4967 * Multi-arched targets.
4969 DEC Alpha (partial) alpha*-*-*
4970 DEC VAX (partial) vax-*-*
4972 National Semiconductor NS32000 (partial) ns32k-*-*
4973 Motorola 68000 (partial) m68k-*-*
4974 Motorola MCORE mcore-*-*
4978 Fujitsu FRV architecture added by Red Hat frv*-*-*
4981 * New native configurations
4983 Alpha NetBSD alpha*-*-netbsd*
4984 SH NetBSD sh*-*-netbsdelf*
4985 MIPS NetBSD mips*-*-netbsd*
4986 UltraSPARC NetBSD sparc64-*-netbsd*
4988 * OBSOLETE configurations and files
4990 Configurations that have been declared obsolete in this release have
4991 been commented out. Unless there is activity to revive these
4992 configurations, the next release of GDB will have their sources
4993 permanently REMOVED.
4995 Mitsubishi D30V d30v-*-*
4996 OS/9000 i[34]86-*-os9k
4997 IBM AIX PS/2 i[3456]86-*-aix
4998 Fujitsu FR30 fr30-*-elf*
4999 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5000 Argonaut Risc Chip (ARC) arc-*-*
5001 i386 running Mach 3.0 i[3456]86-*-mach3*
5002 i386 running Mach i[3456]86-*-mach*
5003 i386 running OSF/1 i[3456]86-*osf1mk*
5004 HP/Apollo 68k Family m68*-apollo*-sysv*,
5006 m68*-hp-bsd*, m68*-hp-hpux*
5007 I960 with MON960 i960-*-coff
5009 * OBSOLETE languages
5011 CHILL, a Pascal like language used by telecommunications companies.
5013 * REMOVED configurations and files
5015 AMD 29k family via UDI a29k-amd-udi, udi29k
5016 A29K VxWorks a29k-*-vxworks
5017 AMD 29000 embedded, using EBMON a29k-none-none
5018 AMD 29000 embedded with COFF a29k-none-coff
5019 AMD 29000 embedded with a.out a29k-none-aout
5021 testsuite/gdb.hp/gdb.threads-hp/ directory
5023 * New command "set max-user-call-depth <nnn>"
5025 This command allows the user to limit the call depth of user-defined
5026 commands. The default is 1024.
5028 * Changes in FreeBSD/i386 native debugging.
5030 Support for the "generate-core-file" has been added.
5032 * New commands "dump", "append", and "restore".
5034 These commands allow data to be copied from target memory
5035 to a bfd-format or binary file (dump and append), and back
5036 from a file into memory (restore).
5038 * Improved "next/step" support on multi-processor Alpha Tru64.
5040 The previous single-step mechanism could cause unpredictable problems,
5041 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5042 of a software single-step mechanism prevents this.
5044 *** Changes in GDB 5.2.1:
5052 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5053 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5054 Fix, by Joel Brobecker imported from mainline.
5056 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5057 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5058 Fix, by Fred Fish, imported from mainline.
5060 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5061 Surprisingly enough, it works now.
5062 By Michal Ludvig, imported from mainline.
5064 i386 hardware watchpoint support:
5065 avoid misses on second run for some targets.
5066 By Pierre Muller, imported from mainline.
5068 *** Changes in GDB 5.2:
5070 * New command "set trust-readonly-sections on[off]".
5072 This command is a hint that tells gdb that read-only sections
5073 really are read-only (ie. that their contents will not change).
5074 In this mode, gdb will go to the object file rather than the
5075 target to read memory from read-only sections (such as ".text").
5076 This can be a significant performance improvement on some
5077 (notably embedded) targets.
5079 * New command "generate-core-file" (or "gcore").
5081 This new gdb command allows the user to drop a core file of the child
5082 process state at any time. So far it's been implemented only for
5083 GNU/Linux and Solaris, but should be relatively easily ported to other
5084 hosts. Argument is core file name (defaults to core.<pid>).
5086 * New command line option
5088 GDB now accepts --pid or -p followed by a process id.
5090 * Change in command line behavior -- corefiles vs. process ids.
5092 There is a subtle behavior in the way in which GDB handles
5093 command line arguments. The first non-flag argument is always
5094 a program to debug, but the second non-flag argument may either
5095 be a corefile or a process id. Previously, GDB would attempt to
5096 open the second argument as a corefile, and if that failed, would
5097 issue a superfluous error message and then attempt to attach it as
5098 a process. Now, if the second argument begins with a non-digit,
5099 it will be treated as a corefile. If it begins with a digit,
5100 GDB will attempt to attach it as a process, and if no such process
5101 is found, will then attempt to open it as a corefile.
5103 * Changes in ARM configurations.
5105 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5106 configuration is fully multi-arch.
5108 * New native configurations
5110 ARM NetBSD arm*-*-netbsd*
5111 x86 OpenBSD i[3456]86-*-openbsd*
5112 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5113 Sparc64 running FreeBSD sparc64-*-freebsd*
5117 Sanyo XStormy16 xstormy16-elf
5119 * OBSOLETE configurations and files
5121 Configurations that have been declared obsolete in this release have
5122 been commented out. Unless there is activity to revive these
5123 configurations, the next release of GDB will have their sources
5124 permanently REMOVED.
5126 AMD 29k family via UDI a29k-amd-udi, udi29k
5127 A29K VxWorks a29k-*-vxworks
5128 AMD 29000 embedded, using EBMON a29k-none-none
5129 AMD 29000 embedded with COFF a29k-none-coff
5130 AMD 29000 embedded with a.out a29k-none-aout
5132 testsuite/gdb.hp/gdb.threads-hp/ directory
5134 * REMOVED configurations and files
5136 TI TMS320C80 tic80-*-*
5138 PowerPC Solaris powerpcle-*-solaris*
5139 PowerPC Windows NT powerpcle-*-cygwin32
5140 PowerPC Netware powerpc-*-netware*
5141 Harris/CXUX m88k m88*-harris-cxux*
5142 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5143 ns32k-utek-sysv* ns32k-utek-*
5144 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5145 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5146 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5147 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5148 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5150 * Changes to command line processing
5152 The new `--args' feature can be used to specify command-line arguments
5153 for the inferior from gdb's command line.
5155 * Changes to key bindings
5157 There is a new `operate-and-get-next' function bound to `C-o'.
5159 *** Changes in GDB 5.1.1
5161 Fix compile problem on DJGPP.
5163 Fix a problem with floating-point registers on the i386 being
5166 Fix to stop GDB crashing on .debug_str debug info.
5168 Numerous documentation fixes.
5170 Numerous testsuite fixes.
5172 *** Changes in GDB 5.1:
5174 * New native configurations
5176 Alpha FreeBSD alpha*-*-freebsd*
5177 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5178 MIPS GNU/Linux mips*-*-linux*
5179 MIPS SGI Irix 6.x mips*-sgi-irix6*
5180 ia64 AIX ia64-*-aix*
5181 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5185 Motorola 68HC11 and 68HC12 m68hc11-elf
5187 UltraSparc running GNU/Linux sparc64-*-linux*
5189 * OBSOLETE configurations and files
5191 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5192 Harris/CXUX m88k m88*-harris-cxux*
5193 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5194 ns32k-utek-sysv* ns32k-utek-*
5195 TI TMS320C80 tic80-*-*
5197 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5198 PowerPC Solaris powerpcle-*-solaris*
5199 PowerPC Windows NT powerpcle-*-cygwin32
5200 PowerPC Netware powerpc-*-netware*
5201 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5202 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5203 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5204 Apple Macintosh (MPW) host N/A
5206 stuff.c (Program to stuff files into a specially prepared space in kdb)
5207 kdb-start.c (Main loop for the standalone kernel debugger)
5209 Configurations that have been declared obsolete in this release have
5210 been commented out. Unless there is activity to revive these
5211 configurations, the next release of GDB will have their sources
5212 permanently REMOVED.
5214 * REMOVED configurations and files
5216 Altos 3068 m68*-altos-*
5217 Convex c1-*-*, c2-*-*
5219 ARM RISCix arm-*-* (as host)
5223 * GDB has been converted to ISO C.
5225 GDB's source code has been converted to ISO C. In particular, the
5226 sources are fully protoized, and rely on standard headers being
5231 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5233 * The MI enabled by default.
5235 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5236 revised and enabled by default. Packages which use GDB as a debugging
5237 engine behind a UI or another front end are encouraged to switch to
5238 using the GDB/MI interface, instead of the old annotations interface
5239 which is now deprecated.
5241 * Support for debugging Pascal programs.
5243 GDB now includes support for debugging Pascal programs. The following
5244 main features are supported:
5246 - Pascal-specific data types such as sets;
5248 - automatic recognition of Pascal sources based on file-name
5251 - Pascal-style display of data types, variables, and functions;
5253 - a Pascal expression parser.
5255 However, some important features are not yet supported.
5257 - Pascal string operations are not supported at all;
5259 - there are some problems with boolean types;
5261 - Pascal type hexadecimal constants are not supported
5262 because they conflict with the internal variables format;
5264 - support for Pascal objects and classes is not full yet;
5266 - unlike Pascal, GDB is case-sensitive for symbol names.
5268 * Changes in completion.
5270 Commands such as `shell', `run' and `set args', which pass arguments
5271 to inferior programs, now complete on file names, similar to what
5272 users expect at the shell prompt.
5274 Commands which accept locations, such as `disassemble', `print',
5275 `breakpoint', `until', etc. now complete on filenames as well as
5276 program symbols. Thus, if you type "break foob TAB", and the source
5277 files linked into the programs include `foobar.c', that file name will
5278 be one of the candidates for completion. However, file names are not
5279 considered for completion after you typed a colon that delimits a file
5280 name from a name of a function in that file, as in "break foo.c:bar".
5282 `set demangle-style' completes on available demangling styles.
5284 * New platform-independent commands:
5286 It is now possible to define a post-hook for a command as well as a
5287 hook that runs before the command. For more details, see the
5288 documentation of `hookpost' in the GDB manual.
5290 * Changes in GNU/Linux native debugging.
5292 Support for debugging multi-threaded programs has been completely
5293 revised for all platforms except m68k and sparc. You can now debug as
5294 many threads as your system allows you to have.
5296 Attach/detach is supported for multi-threaded programs.
5298 Support for SSE registers was added for x86. This doesn't work for
5299 multi-threaded programs though.
5301 * Changes in MIPS configurations.
5303 Multi-arch support is enabled for all MIPS configurations.
5305 GDB can now be built as native debugger on SGI Irix 6.x systems for
5306 debugging n32 executables. (Debugging 64-bit executables is not yet
5309 * Unified support for hardware watchpoints in all x86 configurations.
5311 Most (if not all) native x86 configurations support hardware-assisted
5312 breakpoints and watchpoints in a unified manner. This support
5313 implements debug register sharing between watchpoints, which allows to
5314 put a virtually infinite number of watchpoints on the same address,
5315 and also supports watching regions up to 16 bytes with several debug
5318 The new maintenance command `maintenance show-debug-regs' toggles
5319 debugging print-outs in functions that insert, remove, and test
5320 watchpoints and hardware breakpoints.
5322 * Changes in the DJGPP native configuration.
5324 New command ``info dos sysinfo'' displays assorted information about
5325 the CPU, OS, memory, and DPMI server.
5327 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5328 display information about segment descriptors stored in GDT, LDT, and
5331 New commands ``info dos pde'' and ``info dos pte'' display entries
5332 from Page Directory and Page Tables (for now works with CWSDPMI only).
5333 New command ``info dos address-pte'' displays the Page Table entry for
5334 a given linear address.
5336 GDB can now pass command lines longer than 126 characters to the
5337 program being debugged (requires an update to the libdbg.a library
5338 which is part of the DJGPP development kit).
5340 DWARF2 debug info is now supported.
5342 It is now possible to `step' and `next' through calls to `longjmp'.
5344 * Changes in documentation.
5346 All GDB documentation was converted to GFDL, the GNU Free
5347 Documentation License.
5349 Tracepoints-related commands are now fully documented in the GDB
5352 TUI, the Text-mode User Interface, is now documented in the manual.
5354 Tracepoints-related commands are now fully documented in the GDB
5357 The "GDB Internals" manual now has an index. It also includes
5358 documentation of `ui_out' functions, GDB coding standards, x86
5359 hardware watchpoints, and memory region attributes.
5361 * GDB's version number moved to ``version.in''
5363 The Makefile variable VERSION has been replaced by the file
5364 ``version.in''. People creating GDB distributions should update the
5365 contents of this file.
5369 GUD support is now a standard part of the EMACS distribution.
5371 *** Changes in GDB 5.0:
5373 * Improved support for debugging FP programs on x86 targets
5375 Unified and much-improved support for debugging floating-point
5376 programs on all x86 targets. In particular, ``info float'' now
5377 displays the FP registers in the same format on all x86 targets, with
5378 greater level of detail.
5380 * Improvements and bugfixes in hardware-assisted watchpoints
5382 It is now possible to watch array elements, struct members, and
5383 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5384 on x86 targets no longer erroneously trigger when the address is
5387 * Improvements in the native DJGPP version of GDB
5389 The distribution now includes all the scripts and auxiliary files
5390 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5391 machines ``out of the box''.
5393 The DJGPP version can now debug programs that use signals. It is
5394 possible to catch signals that happened in the debuggee, deliver
5395 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5396 would kill the program being debugged.) Programs that hook hardware
5397 interrupts (keyboard, timer, etc.) can also be debugged.
5399 It is now possible to debug DJGPP programs that redirect their
5400 standard handles or switch them to raw (as opposed to cooked) mode, or
5401 even close them. The command ``run < foo > bar'' works as expected,
5402 and ``info terminal'' reports useful information about the debuggee's
5403 terminal, including raw/cooked mode, redirection, etc.
5405 The DJGPP version now uses termios functions for console I/O, which
5406 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5409 DOS-style file names with drive letters are now fully supported by
5412 It is now possible to debug DJGPP programs that switch their working
5413 directory. It is also possible to rerun the debuggee any number of
5414 times without restarting GDB; thus, you can use the same setup,
5415 breakpoints, etc. for many debugging sessions.
5417 * New native configurations
5419 ARM GNU/Linux arm*-*-linux*
5420 PowerPC GNU/Linux powerpc-*-linux*
5424 Motorola MCore mcore-*-*
5425 x86 VxWorks i[3456]86-*-vxworks*
5426 PowerPC VxWorks powerpc-*-vxworks*
5427 TI TMS320C80 tic80-*-*
5429 * OBSOLETE configurations
5431 Altos 3068 m68*-altos-*
5432 Convex c1-*-*, c2-*-*
5434 ARM RISCix arm-*-* (as host)
5437 Configurations that have been declared obsolete will be commented out,
5438 but the code will be left in place. If there is no activity to revive
5439 these configurations before the next release of GDB, the sources will
5440 be permanently REMOVED.
5442 * Gould support removed
5444 Support for the Gould PowerNode and NP1 has been removed.
5446 * New features for SVR4
5448 On SVR4 native platforms (such as Solaris), if you attach to a process
5449 without first loading a symbol file, GDB will now attempt to locate and
5450 load symbols from the running process's executable file.
5452 * Many C++ enhancements
5454 C++ support has been greatly improved. Overload resolution now works properly
5455 in almost all cases. RTTI support is on the way.
5457 * Remote targets can connect to a sub-program
5459 A popen(3) style serial-device has been added. This device starts a
5460 sub-process (such as a stand-alone simulator) and then communicates
5461 with that. The sub-program to run is specified using the syntax
5462 ``|<program> <args>'' vis:
5464 (gdb) set remotedebug 1
5465 (gdb) target extended-remote |mn10300-elf-sim program-args
5467 * MIPS 64 remote protocol
5469 A long standing bug in the mips64 remote protocol where by GDB
5470 expected certain 32 bit registers (ex SR) to be transfered as 32
5471 instead of 64 bits has been fixed.
5473 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5474 added to provide backward compatibility with older versions of GDB.
5476 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5478 The command ``set remotebinarydownload'' command has been replaced by
5479 ``set remote X-packet''. Other commands in ``set remote'' family
5480 include ``set remote P-packet''.
5482 * Breakpoint commands accept ranges.
5484 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5485 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5486 ``tracepoint passcount'' also accepts a range of tracepoints.
5488 * ``apropos'' command added.
5490 The ``apropos'' command searches through command names and
5491 documentation strings, printing out matches, making it much easier to
5492 try to find a command that does what you are looking for.
5496 A new machine oriented interface (MI) has been added to GDB. This
5497 interface is designed for debug environments running GDB as a separate
5498 process. This is part of the long term libGDB project. See the
5499 "GDB/MI" chapter of the GDB manual for further information. It can be
5500 enabled by configuring with:
5502 .../configure --enable-gdbmi
5504 *** Changes in GDB-4.18:
5506 * New native configurations
5508 HP-UX 10.20 hppa*-*-hpux10.20
5509 HP-UX 11.x hppa*-*-hpux11.0*
5510 M68K GNU/Linux m68*-*-linux*
5514 Fujitsu FR30 fr30-*-elf*
5515 Intel StrongARM strongarm-*-*
5516 Mitsubishi D30V d30v-*-*
5518 * OBSOLETE configurations
5520 Gould PowerNode, NP1 np1-*-*, pn-*-*
5522 Configurations that have been declared obsolete will be commented out,
5523 but the code will be left in place. If there is no activity to revive
5524 these configurations before the next release of GDB, the sources will
5525 be permanently REMOVED.
5529 As a compatibility experiment, GDB's source files buildsym.h and
5530 buildsym.c have been converted to pure standard C, no longer
5531 containing any K&R compatibility code. We believe that all systems in
5532 use today either come with a standard C compiler, or have a GCC port
5533 available. If this is not true, please report the affected
5534 configuration to bug-gdb@gnu.org immediately. See the README file for
5535 information about getting a standard C compiler if you don't have one
5540 GDB now uses readline 2.2.
5542 * set extension-language
5544 You can now control the mapping between filename extensions and source
5545 languages by using the `set extension-language' command. For instance,
5546 you can ask GDB to treat .c files as C++ by saying
5547 set extension-language .c c++
5548 The command `info extensions' lists all of the recognized extensions
5549 and their associated languages.
5551 * Setting processor type for PowerPC and RS/6000
5553 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5554 you can use the `set processor' command to specify what variant of the
5555 PowerPC family you are debugging. The command
5559 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5560 following PowerPC and RS6000 variants:
5562 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5563 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5565 403GC IBM PowerPC 403GC
5566 505 Motorola PowerPC 505
5567 860 Motorola PowerPC 860 or 850
5568 601 Motorola PowerPC 601
5569 602 Motorola PowerPC 602
5570 603 Motorola/IBM PowerPC 603 or 603e
5571 604 Motorola PowerPC 604 or 604e
5572 750 Motorola/IBM PowerPC 750 or 750
5574 At the moment, this command just tells GDB what to name the
5575 special-purpose processor registers. Since almost all the affected
5576 registers are inaccessible to user-level programs, this command is
5577 only useful for remote debugging in its present form.
5581 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5582 more extensive support for HP-UX. Added features include shared
5583 library support, kernel threads and hardware watchpoints for 11.00,
5584 support for HP's ANSI C and C++ compilers, and a compatibility mode
5585 for xdb and dbx commands.
5589 HP's donation includes the new concept of catchpoints, which is a
5590 generalization of the old catch command. On HP-UX, it is now possible
5591 to catch exec, fork, and vfork, as well as library loading.
5593 This means that the existing catch command has changed; its first
5594 argument now specifies the type of catch to be set up. See the
5595 output of "help catch" for a list of catchpoint types.
5597 * Debugging across forks
5599 On HP-UX, you can choose which process to debug when a fork() happens
5604 HP has donated a curses-based terminal user interface (TUI). To get
5605 it, build with --enable-tui. Although this can be enabled for any
5606 configuration, at present it only works for native HP debugging.
5608 * GDB remote protocol additions
5610 A new protocol packet 'X' that writes binary data is now available.
5611 Default behavior is to try 'X', then drop back to 'M' if the stub
5612 fails to respond. The settable variable `remotebinarydownload'
5613 allows explicit control over the use of 'X'.
5615 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5616 full 64-bit address. The command
5618 set remoteaddresssize 32
5620 can be used to revert to the old behaviour. For existing remote stubs
5621 the change should not be noticed, as the additional address information
5624 In order to assist in debugging stubs, you may use the maintenance
5625 command `packet' to send any text string to the stub. For instance,
5627 maint packet heythere
5629 sends the packet "$heythere#<checksum>". Note that it is very easy to
5630 disrupt a debugging session by sending the wrong packet at the wrong
5633 The compare-sections command allows you to compare section data on the
5634 target to what is in the executable file without uploading or
5635 downloading, by comparing CRC checksums.
5637 * Tracing can collect general expressions
5639 You may now collect general expressions at tracepoints. This requires
5640 further additions to the target-side stub; see tracepoint.c and
5641 doc/agentexpr.texi for further details.
5643 * mask-address variable for Mips
5645 For Mips targets, you may control the zeroing of the upper 32 bits of
5646 a 64-bit address by entering `set mask-address on'. This is mainly
5647 of interest to users of embedded R4xxx and R5xxx processors.
5649 * Higher serial baud rates
5651 GDB's serial code now allows you to specify baud rates 57600, 115200,
5652 230400, and 460800 baud. (Note that your host system may not be able
5653 to achieve all of these rates.)
5657 The i960 configuration now includes an initial implementation of a
5658 builtin simulator, contributed by Jim Wilson.
5661 *** Changes in GDB-4.17:
5663 * New native configurations
5665 Alpha GNU/Linux alpha*-*-linux*
5666 Unixware 2.x i[3456]86-unixware2*
5667 Irix 6.x mips*-sgi-irix6*
5668 PowerPC GNU/Linux powerpc-*-linux*
5669 PowerPC Solaris powerpcle-*-solaris*
5670 Sparc GNU/Linux sparc-*-linux*
5671 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5675 Argonaut Risc Chip (ARC) arc-*-*
5676 Hitachi H8/300S h8300*-*-*
5677 Matsushita MN10200 w/simulator mn10200-*-*
5678 Matsushita MN10300 w/simulator mn10300-*-*
5679 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5680 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5681 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5682 Mitsubishi D10V w/simulator d10v-*-*
5683 Mitsubishi M32R/D w/simulator m32r-*-elf*
5684 Tsqware Sparclet sparclet-*-*
5685 NEC V850 w/simulator v850-*-*
5687 * New debugging protocols
5689 ARM with RDI protocol arm*-*-*
5690 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5691 DDB and LSI variants of PMON protocol mips*-*-*
5692 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5693 PowerPC with SDS protocol powerpc{,le}-*-eabi
5694 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5698 All configurations can now understand and use the DWARF 2 debugging
5699 format. The choice is automatic, if the symbol file contains DWARF 2
5704 GDB now includes basic Java language support. This support is
5705 only useful with Java compilers that produce native machine code.
5707 * solib-absolute-prefix and solib-search-path
5709 For SunOS and SVR4 shared libraries, you may now set the prefix for
5710 loading absolute shared library symbol files, and the search path for
5711 locating non-absolute shared library symbol files.
5713 * Live range splitting
5715 GDB can now effectively debug code for which GCC has performed live
5716 range splitting as part of its optimization. See gdb/doc/LRS for
5717 more details on the expected format of the stabs information.
5721 GDB's support for the GNU Hurd, including thread debugging, has been
5722 updated to work with current versions of the Hurd.
5726 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5727 instruction set. ARM GDB automatically detects when Thumb
5728 instructions are in use, and adjusts disassembly and backtracing
5733 GDB's MIPS target configurations now handle the MIP16 16-bit
5738 GDB now includes support for overlays; if an executable has been
5739 linked such that multiple sections are based at the same address, GDB
5740 will decide which section to use for symbolic info. You can choose to
5741 control the decision manually, using overlay commands, or implement
5742 additional target-side support and use "overlay load-target" to bring
5743 in the overlay mapping. Do "help overlay" for more detail.
5747 The command "info symbol <address>" displays information about
5748 the symbol at the specified address.
5752 The standard remote protocol now includes an extension that allows
5753 asynchronous collection and display of trace data. This requires
5754 extensive support in the target-side debugging stub. Tracing mode
5755 includes a new interaction mode in GDB and new commands: see the
5756 file tracepoint.c for more details.
5760 Configurations for embedded MIPS now include a simulator contributed
5761 by Cygnus Solutions. The simulator supports the instruction sets
5762 of most MIPS variants.
5766 Sparc configurations may now include the ERC32 simulator contributed
5767 by the European Space Agency. The simulator is not built into
5768 Sparc targets by default; configure with --enable-sim to include it.
5772 For target configurations that may include multiple variants of a
5773 basic architecture (such as MIPS and SH), you may now set the
5774 architecture explicitly. "set arch" sets, "info arch" lists
5775 the possible architectures.
5777 *** Changes in GDB-4.16:
5779 * New native configurations
5781 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5782 M68K NetBSD m68k-*-netbsd*
5783 PowerPC AIX 4.x powerpc-*-aix*
5784 PowerPC MacOS powerpc-*-macos*
5785 PowerPC Windows NT powerpcle-*-cygwin32
5786 RS/6000 AIX 4.x rs6000-*-aix4*
5790 ARM with RDP protocol arm-*-*
5791 I960 with MON960 i960-*-coff
5792 MIPS VxWorks mips*-*-vxworks*
5793 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5794 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5796 Matra Sparclet sparclet-*-*
5800 The powerpc-eabi configuration now includes the PSIM simulator,
5801 contributed by Andrew Cagney, with assistance from Mike Meissner.
5802 PSIM is a very elaborate model of the PowerPC, including not only
5803 basic instruction set execution, but also details of execution unit
5804 performance and I/O hardware. See sim/ppc/README for more details.
5808 GDB now works with Solaris 2.5.
5810 * Windows 95/NT native
5812 GDB will now work as a native debugger on Windows 95 and Windows NT.
5813 To build it from source, you must use the "gnu-win32" environment,
5814 which uses a DLL to emulate enough of Unix to run the GNU tools.
5815 Further information, binaries, and sources are available at
5816 ftp.cygnus.com, under pub/gnu-win32.
5818 * dont-repeat command
5820 If a user-defined command includes the command `dont-repeat', then the
5821 command will not be repeated if the user just types return. This is
5822 useful if the command is time-consuming to run, so that accidental
5823 extra keystrokes don't run the same command many times.
5825 * Send break instead of ^C
5827 The standard remote protocol now includes an option to send a break
5828 rather than a ^C to the target in order to interrupt it. By default,
5829 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5831 * Remote protocol timeout
5833 The standard remote protocol includes a new variable `remotetimeout'
5834 that allows you to set the number of seconds before GDB gives up trying
5835 to read from the target. The default value is 2.
5837 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5839 By default GDB will automatically keep track of objects as they are
5840 loaded and unloaded by the dynamic linker. By using the command `set
5841 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5842 when shared library events occur, thus allowing you to set breakpoints
5843 in shared libraries which are explicitly loaded by the inferior.
5845 Note this feature does not work on hpux8. On hpux9 you must link
5846 /usr/lib/end.o into your program. This feature should work
5847 automatically on hpux10.
5849 * Irix 5.x hardware watchpoint support
5851 Irix 5 configurations now support the use of hardware watchpoints.
5853 * Mips protocol "SYN garbage limit"
5855 When debugging a Mips target using the `target mips' protocol, you
5856 may set the number of characters that GDB will ignore by setting
5857 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5858 every character. The default value is 1050.
5860 * Recording and replaying remote debug sessions
5862 If you set `remotelogfile' to the name of a file, gdb will write to it
5863 a recording of a remote debug session. This recording may then be
5864 replayed back to gdb using "gdbreplay". See gdbserver/README for
5865 details. This is useful when you have a problem with GDB while doing
5866 remote debugging; you can make a recording of the session and send it
5867 to someone else, who can then recreate the problem.
5869 * Speedups for remote debugging
5871 GDB includes speedups for downloading and stepping MIPS systems using
5872 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5873 and more efficient S-record downloading.
5875 * Memory use reductions and statistics collection
5877 GDB now uses less memory and reports statistics about memory usage.
5878 Try the `maint print statistics' command, for example.
5880 *** Changes in GDB-4.15:
5882 * Psymtabs for XCOFF
5884 The symbol reader for AIX GDB now uses partial symbol tables. This
5885 can greatly improve startup time, especially for large executables.
5887 * Remote targets use caching
5889 Remote targets now use a data cache to speed up communication with the
5890 remote side. The data cache could lead to incorrect results because
5891 it doesn't know about volatile variables, thus making it impossible to
5892 debug targets which use memory mapped I/O devices. `set remotecache
5893 off' turns the the data cache off.
5895 * Remote targets may have threads
5897 The standard remote protocol now includes support for multiple threads
5898 in the target system, using new protocol commands 'H' and 'T'. See
5899 gdb/remote.c for details.
5903 If GDB is configured with `--enable-netrom', then it will include
5904 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5905 acts as though it is a bank of ROM on the target board, but you can
5906 write into it over the network. GDB's support consists only of
5907 support for fast loading into the emulated ROM; to debug, you must use
5908 another protocol, such as standard remote protocol. The usual
5909 sequence is something like
5911 target nrom <netrom-hostname>
5913 target remote <netrom-hostname>:1235
5917 GDB now includes support for the Apple Macintosh, as a host only. It
5918 may be run as either an MPW tool or as a standalone application, and
5919 it can debug through the serial port. All the usual GDB commands are
5920 available, but to the target command, you must supply "serial" as the
5921 device type instead of "/dev/ttyXX". See mpw-README in the main
5922 directory for more information on how to build. The MPW configuration
5923 scripts */mpw-config.in support only a few targets, and only the
5924 mips-idt-ecoff target has been tested.
5928 GDB configuration now uses autoconf. This is not user-visible,
5929 but does simplify configuration and building.
5933 GDB now supports hpux10.
5935 *** Changes in GDB-4.14:
5937 * New native configurations
5939 x86 FreeBSD i[345]86-*-freebsd
5940 x86 NetBSD i[345]86-*-netbsd
5941 NS32k NetBSD ns32k-*-netbsd
5942 Sparc NetBSD sparc-*-netbsd
5946 A29K VxWorks a29k-*-vxworks
5947 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5948 CPU32 EST-300 emulator m68*-*-est*
5949 PowerPC ELF powerpc-*-elf
5952 * Alpha OSF/1 support for procfs
5954 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5955 possible to attach to running processes. As the mounting of the /proc
5956 filesystem is optional on the Alpha, GDB automatically determines
5957 the availability of /proc during startup. This can lead to problems
5958 if /proc is unmounted after GDB has been started.
5960 * Arguments to user-defined commands
5962 User commands may accept up to 10 arguments separated by whitespace.
5963 Arguments are accessed within the user command via $arg0..$arg9. A
5966 print $arg0 + $arg1 + $arg2
5968 To execute the command use:
5971 Defines the command "adder" which prints the sum of its three arguments.
5972 Note the arguments are text substitutions, so they may reference variables,
5973 use complex expressions, or even perform inferior function calls.
5975 * New `if' and `while' commands
5977 This makes it possible to write more sophisticated user-defined
5978 commands. Both commands take a single argument, which is the
5979 expression to evaluate, and must be followed by the commands to
5980 execute, one per line, if the expression is nonzero, the list being
5981 terminated by the word `end'. The `if' command list may include an
5982 `else' word, which causes the following commands to be executed only
5983 if the expression is zero.
5985 * Fortran source language mode
5987 GDB now includes partial support for Fortran 77. It will recognize
5988 Fortran programs and can evaluate a subset of Fortran expressions, but
5989 variables and functions may not be handled correctly. GDB will work
5990 with G77, but does not yet know much about symbols emitted by other
5993 * Better HPUX support
5995 Most debugging facilities now work on dynamic executables for HPPAs
5996 running hpux9 or later. You can attach to running dynamically linked
5997 processes, but by default the dynamic libraries will be read-only, so
5998 for instance you won't be able to put breakpoints in them. To change
5999 that behavior do the following before running the program:
6005 This will cause the libraries to be mapped private and read-write.
6006 To revert to the normal behavior, do this:
6012 You cannot set breakpoints or examine data in the library until after
6013 the library is loaded if the function/data symbols do not have
6016 GDB can now also read debug symbols produced by the HP C compiler on
6017 HPPAs (sorry, no C++, Fortran or 68k support).
6019 * Target byte order now dynamically selectable
6021 You can choose which byte order to use with a target system, via the
6022 commands "set endian big" and "set endian little", and you can see the
6023 current setting by using "show endian". You can also give the command
6024 "set endian auto", in which case GDB will use the byte order
6025 associated with the executable. Currently, only embedded MIPS
6026 configurations support dynamic selection of target byte order.
6028 * New DOS host serial code
6030 This version uses DPMI interrupts to handle buffered I/O, so you
6031 no longer need to run asynctsr when debugging boards connected to
6034 *** Changes in GDB-4.13:
6036 * New "complete" command
6038 This lists all the possible completions for the rest of the line, if it
6039 were to be given as a command itself. This is intended for use by emacs.
6041 * Trailing space optional in prompt
6043 "set prompt" no longer adds a space for you after the prompt you set. This
6044 allows you to set a prompt which ends in a space or one that does not.
6046 * Breakpoint hit counts
6048 "info break" now displays a count of the number of times the breakpoint
6049 has been hit. This is especially useful in conjunction with "ignore"; you
6050 can ignore a large number of breakpoint hits, look at the breakpoint info
6051 to see how many times the breakpoint was hit, then run again, ignoring one
6052 less than that number, and this will get you quickly to the last hit of
6055 * Ability to stop printing at NULL character
6057 "set print null-stop" will cause GDB to stop printing the characters of
6058 an array when the first NULL is encountered. This is useful when large
6059 arrays actually contain only short strings.
6061 * Shared library breakpoints
6063 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6064 breakpoints in shared libraries before the executable is run.
6066 * Hardware watchpoints
6068 There is a new hardware breakpoint for the watch command for sparclite
6069 targets. See gdb/sparclite/hw_breakpoint.note.
6071 Hardware watchpoints are also now supported under GNU/Linux.
6075 Annotations have been added. These are for use with graphical interfaces,
6076 and are still experimental. Currently only gdba.el uses these.
6078 * Improved Irix 5 support
6080 GDB now works properly with Irix 5.2.
6082 * Improved HPPA support
6084 GDB now works properly with the latest GCC and GAS.
6086 * New native configurations
6088 Sequent PTX4 i[34]86-sequent-ptx4
6089 HPPA running OSF/1 hppa*-*-osf*
6090 Atari TT running SVR4 m68*-*-sysv4*
6091 RS/6000 LynxOS rs6000-*-lynxos*
6095 OS/9000 i[34]86-*-os9k
6096 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6099 * Hitachi SH7000 and E7000-PC ICE support
6101 There is now support for communicating with the Hitachi E7000-PC ICE.
6102 This is available automatically when GDB is configured for the SH.
6106 As usual, a variety of small fixes and improvements, both generic
6107 and configuration-specific. See the ChangeLog for more detail.
6109 *** Changes in GDB-4.12:
6111 * Irix 5 is now supported
6115 GDB-4.12 on the HPPA has a number of changes which make it unable
6116 to debug the output from the currently released versions of GCC and
6117 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6118 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6119 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6122 *** Changes in GDB-4.11:
6124 * User visible changes:
6128 The "set remotedebug" option is now consistent between the mips remote
6129 target, remote targets using the gdb-specific protocol, UDI (AMD's
6130 debug protocol for the 29k) and the 88k bug monitor. It is now an
6131 integer specifying a debug level (normally 0 or 1, but 2 means more
6132 debugging info for the mips target).
6134 * DEC Alpha native support
6136 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6137 debug info, but GDB works fairly well with the DEC compiler and should
6138 work with a future GCC release. See the README file for a few
6139 Alpha-specific notes.
6141 * Preliminary thread implementation
6143 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6145 * LynxOS native and target support for 386
6147 This release has been hosted on LynxOS 2.2, and also can be configured
6148 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6151 * Improvements in C++ mangling/demangling.
6153 This release has much better g++ debugging, specifically in name
6154 mangling/demangling, virtual function calls, print virtual table,
6155 call methods, ...etc.
6157 *** Changes in GDB-4.10:
6159 * User visible changes:
6161 Remote debugging using the GDB-specific (`target remote') protocol now
6162 supports the `load' command. This is only useful if you have some
6163 other way of getting the stub to the target system, and you can put it
6164 somewhere in memory where it won't get clobbered by the download.
6166 Filename completion now works.
6168 When run under emacs mode, the "info line" command now causes the
6169 arrow to point to the line specified. Also, "info line" prints
6170 addresses in symbolic form (as well as hex).
6172 All vxworks based targets now support a user settable option, called
6173 vxworks-timeout. This option represents the number of seconds gdb
6174 should wait for responses to rpc's. You might want to use this if
6175 your vxworks target is, perhaps, a slow software simulator or happens
6176 to be on the far side of a thin network line.
6180 This release contains support for using a DEC alpha as a GDB host for
6181 cross debugging. Native alpha debugging is not supported yet.
6184 *** Changes in GDB-4.9:
6188 This is the first GDB release which is accompanied by a matching testsuite.
6189 The testsuite requires installation of dejagnu, which should be available
6190 via ftp from most sites that carry GNU software.
6194 'Cfront' style demangling has had its name changed to 'ARM' style, to
6195 emphasize that it was written from the specifications in the C++ Annotated
6196 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6197 disclaimers, it still generated too much confusion with users attempting to
6198 use gdb with AT&T cfront.
6202 GDB now uses a standard remote interface to a simulator library.
6203 So far, the library contains simulators for the Zilog Z8001/2, the
6204 Hitachi H8/300, H8/500 and Super-H.
6206 * New targets supported
6208 H8/300 simulator h8300-hitachi-hms or h8300hms
6209 H8/500 simulator h8500-hitachi-hms or h8500hms
6210 SH simulator sh-hitachi-hms or sh
6211 Z8000 simulator z8k-zilog-none or z8ksim
6212 IDT MIPS board over serial line mips-idt-ecoff
6214 Cross-debugging to GO32 targets is supported. It requires a custom
6215 version of the i386-stub.c module which is integrated with the
6216 GO32 memory extender.
6218 * New remote protocols
6220 MIPS remote debugging protocol.
6222 * New source languages supported
6224 This version includes preliminary support for Chill, a Pascal like language
6225 used by telecommunications companies. Chill support is also being integrated
6226 into the GNU compiler, but we don't know when it will be publically available.
6229 *** Changes in GDB-4.8:
6231 * HP Precision Architecture supported
6233 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6234 version of this support was available as a set of patches from the
6235 University of Utah. GDB does not support debugging of programs
6236 compiled with the HP compiler, because HP will not document their file
6237 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6238 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6240 Many problems in the preliminary version have been fixed.
6242 * Faster and better demangling
6244 We have improved template demangling and fixed numerous bugs in the GNU style
6245 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6246 character types (wchar_t) are now supported. Demangling of each symbol is now
6247 only done once, and is cached when the symbol table for a file is read in.
6248 This results in a small increase in memory usage for C programs, a moderate
6249 increase in memory usage for C++ programs, and a fantastic speedup in
6252 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6253 from the specifications in the Annotated Reference Manual, which AT&T's
6254 compiler does not actually implement.
6256 * G++ multiple inheritance compiler problem
6258 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6259 inheritance lattices was reworked to properly discover ambiguities. We
6260 recently found an example which causes this new algorithm to fail in a
6261 very subtle way, producing bad debug information for those classes.
6262 The file 'gcc.patch' (in this directory) can be applied to gcc to
6263 circumvent the problem. A future GCC release will contain a complete
6266 The previous G++ debug info problem (mentioned below for the gdb-4.7
6267 release) is fixed in gcc version 2.3.2.
6269 * Improved configure script
6271 The `configure' script will now attempt to guess your system type if
6272 you don't supply a host system type. The old scheme of supplying a
6273 host system triplet is preferable over using this. All the magic is
6274 done in the new `config.guess' script. Examine it for details.
6276 We have also brought our configure script much more in line with the FSF's
6277 version. It now supports the --with-xxx options. In particular,
6278 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6279 The resulting GDB will not be able to read arbitrary object file formats --
6280 only the format ``expected'' to be used on the configured target system.
6281 We hope to make this the default in a future release.
6283 * Documentation improvements
6285 There's new internal documentation on how to modify GDB, and how to
6286 produce clean changes to the code. We implore people to read it
6287 before submitting changes.
6289 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6290 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6291 `info' files are also provided. To build `info' files from scratch,
6292 you will need the latest `makeinfo' release, which will be available in
6293 a future texinfo-X.Y release.
6295 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6296 We're not sure exactly which versions have this problem, but it has
6297 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6298 or better. If that isn't possible, there is a patch in
6299 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6300 around this problem.
6304 GDB now supports array constants that can be used in expressions typed in by
6305 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6306 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6309 The new directory `gdb/sparclite' contains a program that demonstrates
6310 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6312 * New native hosts supported
6314 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6315 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6317 * New targets supported
6319 AMD 29k family via UDI a29k-amd-udi or udi29k
6321 * New file formats supported
6323 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6324 HPUX core files, and SCO 3.2v2 core files.
6328 Attaching to processes now works again; thanks for the many bug reports.
6330 We have also stomped on a bunch of core dumps caused by
6331 printf_filtered("%s") problems.
6333 We eliminated a copyright problem on the rpc and ptrace header files
6334 for VxWorks, which was discovered at the last minute during the 4.7
6335 release. You should now be able to build a VxWorks GDB.
6337 You can now interrupt gdb while an attached process is running. This
6338 will cause the attached process to stop, and give control back to GDB.
6340 We fixed problems caused by using too many file descriptors
6341 for reading symbols from object files and libraries. This was
6342 especially a problem for programs that used many (~100) shared
6345 The `step' command now only enters a subroutine if there is line number
6346 information for the subroutine. Otherwise it acts like the `next'
6347 command. Previously, `step' would enter subroutines if there was
6348 any debugging information about the routine. This avoids problems
6349 when using `cc -g1' on MIPS machines.
6351 * Internal improvements
6353 GDB's internal interfaces have been improved to make it easier to support
6354 debugging of multiple languages in the future.
6356 GDB now uses a common structure for symbol information internally.
6357 Minimal symbols (derived from linkage symbols in object files), partial
6358 symbols (from a quick scan of debug information), and full symbols
6359 contain a common subset of information, making it easier to write
6360 shared code that handles any of them.
6362 * New command line options
6364 We now accept --silent as an alias for --quiet.
6368 The memory-mapped-malloc library is now licensed under the GNU Library
6369 General Public License.
6371 *** Changes in GDB-4.7:
6373 * Host/native/target split
6375 GDB has had some major internal surgery to untangle the support for
6376 hosts and remote targets. Now, when you configure GDB for a remote
6377 target, it will no longer load in all of the support for debugging
6378 local programs on the host. When fully completed and tested, this will
6379 ensure that arbitrary host/target combinations are possible.
6381 The primary conceptual shift is to separate the non-portable code in
6382 GDB into three categories. Host specific code is required any time GDB
6383 is compiled on that host, regardless of the target. Target specific
6384 code relates to the peculiarities of the target, but can be compiled on
6385 any host. Native specific code is everything else: it can only be
6386 built when the host and target are the same system. Child process
6387 handling and core file support are two common `native' examples.
6389 GDB's use of /proc for controlling Unix child processes is now cleaner.
6390 It has been split out into a single module under the `target_ops' vector,
6391 plus two native-dependent functions for each system that uses /proc.
6393 * New hosts supported
6395 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6396 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6397 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6399 * New targets supported
6401 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6402 68030 and CPU32 m68030-*-*, m68332-*-*
6404 * New native hosts supported
6406 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6407 (386bsd is not well tested yet)
6408 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6410 * New file formats supported
6412 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6413 supports reading of `a.out.adobe' object files, which are an a.out
6414 format extended with minimal information about multiple sections.
6418 `show copying' is the same as the old `info copying'.
6419 `show warranty' is the same as `info warrantee'.
6420 These were renamed for consistency. The old commands continue to work.
6422 `info handle' is a new alias for `info signals'.
6424 You can now define pre-command hooks, which attach arbitrary command
6425 scripts to any command. The commands in the hook will be executed
6426 prior to the user's command. You can also create a hook which will be
6427 executed whenever the program stops. See gdb.texinfo.
6431 We now deal with Cfront style name mangling, and can even extract type
6432 info from mangled symbols. GDB can automatically figure out which
6433 symbol mangling style your C++ compiler uses.
6435 Calling of methods and virtual functions has been improved as well.
6439 The crash that occured when debugging Sun Ansi-C compiled binaries is
6440 fixed. This was due to mishandling of the extra N_SO stabs output
6443 We also finally got Ultrix 4.2 running in house, and fixed core file
6444 support, with help from a dozen people on the net.
6446 John M. Farrell discovered that the reason that single-stepping was so
6447 slow on all of the Mips based platforms (primarily SGI and DEC) was
6448 that we were trying to demangle and lookup a symbol used for internal
6449 purposes on every instruction that was being stepped through. Changing
6450 the name of that symbol so that it couldn't be mistaken for a C++
6451 mangled symbol sped things up a great deal.
6453 Rich Pixley sped up symbol lookups in general by getting much smarter
6454 about when C++ symbol mangling is necessary. This should make symbol
6455 completion (TAB on the command line) much faster. It's not as fast as
6456 we'd like, but it's significantly faster than gdb-4.6.
6460 A new user controllable variable 'call_scratch_address' can
6461 specify the location of a scratch area to be used when GDB
6462 calls a function in the target. This is necessary because the
6463 usual method of putting the scratch area on the stack does not work
6464 in systems that have separate instruction and data spaces.
6466 We integrated changes to support the 29k UDI (Universal Debugger
6467 Interface), but discovered at the last minute that we didn't have all
6468 of the appropriate copyright paperwork. We are working with AMD to
6469 resolve this, and hope to have it available soon.
6473 We have sped up the remote serial line protocol, especially for targets
6474 with lots of registers. It now supports a new `expedited status' ('T')
6475 message which can be used in place of the existing 'S' status message.
6476 This allows the remote stub to send only the registers that GDB
6477 needs to make a quick decision about single-stepping or conditional
6478 breakpoints, eliminating the need to fetch the entire register set for
6479 each instruction being stepped through.
6481 The GDB remote serial protocol now implements a write-through cache for
6482 registers, only re-reading the registers if the target has run.
6484 There is also a new remote serial stub for SPARC processors. You can
6485 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6486 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6487 processor with a serial port.
6491 Configure.in files have become much easier to read and modify. A new
6492 `table driven' format makes it more obvious what configurations are
6493 supported, and what files each one uses.
6497 There is a new opcodes library which will eventually contain all of the
6498 disassembly routines and opcode tables. At present, it only contains
6499 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6500 disassembler (binutils/objdump) to share these routines.
6502 The libiberty library is now copylefted under the GNU Library General
6503 Public License. This allows more liberal use, and was done so libg++
6504 can use it. This makes no difference to GDB, since the Library License
6505 grants all the rights from the General Public License.
6509 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6510 reference to the stabs symbol info used by the debugger. It is (as far
6511 as we know) the only published document on this fascinating topic. We
6512 encourage you to read it, compare it to the stabs information on your
6513 system, and send improvements on the document in general (to
6514 bug-gdb@prep.ai.mit.edu).
6516 And, of course, many bugs have been fixed.
6519 *** Changes in GDB-4.6:
6521 * Better support for C++ function names
6523 GDB now accepts as input the "demangled form" of C++ overloaded function
6524 names and member function names, and can do command completion on such names
6525 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6526 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6527 Make use of command completion, it is your friend.
6529 GDB also now accepts a variety of C++ mangled symbol formats. They are
6530 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6531 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6532 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6533 for the list of formats.
6535 * G++ symbol mangling problem
6537 Recent versions of gcc have a bug in how they emit debugging information for
6538 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6539 directory) can be applied to gcc to fix the problem. Alternatively, if you
6540 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6541 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6542 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6545 * New 'maintenance' command
6547 All of the commands related to hacking GDB internals have been moved out of
6548 the main command set, and now live behind the 'maintenance' command. This
6549 can also be abbreviated as 'mt'. The following changes were made:
6551 dump-me -> maintenance dump-me
6552 info all-breakpoints -> maintenance info breakpoints
6553 printmsyms -> maintenance print msyms
6554 printobjfiles -> maintenance print objfiles
6555 printpsyms -> maintenance print psymbols
6556 printsyms -> maintenance print symbols
6558 The following commands are new:
6560 maintenance demangle Call internal GDB demangler routine to
6561 demangle a C++ link name and prints the result.
6562 maintenance print type Print a type chain for a given symbol
6564 * Change to .gdbinit file processing
6566 We now read the $HOME/.gdbinit file before processing the argv arguments
6567 (e.g. reading symbol files or core files). This allows global parameters to
6568 be set, which will apply during the symbol reading. The ./.gdbinit is still
6569 read after argv processing.
6571 * New hosts supported
6573 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6575 GNU/Linux support i386-unknown-linux or linux
6577 We are also including code to support the HP/PA running BSD and HPUX. This
6578 is almost guaranteed not to work, as we didn't have time to test or build it
6579 for this release. We are including it so that the more adventurous (or
6580 masochistic) of you can play with it. We also had major problems with the
6581 fact that the compiler that we got from HP doesn't support the -g option.
6584 * New targets supported
6586 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6588 * More smarts about finding #include files
6590 GDB now remembers the compilation directory for all include files, and for
6591 all files from which C is generated (like yacc and lex sources). This
6592 greatly improves GDB's ability to find yacc/lex sources, and include files,
6593 especially if you are debugging your program from a directory different from
6594 the one that contains your sources.
6596 We also fixed a bug which caused difficulty with listing and setting
6597 breakpoints in include files which contain C code. (In the past, you had to
6598 try twice in order to list an include file that you hadn't looked at before.)
6600 * Interesting infernals change
6602 GDB now deals with arbitrary numbers of sections, where the symbols for each
6603 section must be relocated relative to that section's landing place in the
6604 target's address space. This work was needed to support ELF with embedded
6605 stabs used by Solaris-2.0.
6607 * Bug fixes (of course!)
6609 There have been loads of fixes for the following things:
6610 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6611 i960, stabs, DOS(GO32), procfs, etc...
6613 See the ChangeLog for details.
6615 *** Changes in GDB-4.5:
6617 * New machines supported (host and target)
6619 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6621 SGI Irix-4.x mips-sgi-irix4 or iris4
6623 * New malloc package
6625 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6626 Mmalloc is capable of handling mutiple heaps of memory. It is also
6627 capable of saving a heap to a file, and then mapping it back in later.
6628 This can be used to greatly speedup the startup of GDB by using a
6629 pre-parsed symbol table which lives in a mmalloc managed heap. For
6630 more details, please read mmalloc/mmalloc.texi.
6634 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6635 'help info proc' for details.
6637 * MIPS ecoff symbol table format
6639 The code that reads MIPS symbol table format is now supported on all hosts.
6640 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6643 * File name changes for MS-DOS
6645 Many files in the config directories have been renamed to make it easier to
6646 support GDB on MS-DOSe systems (which have very restrictive file name
6647 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6648 environment) is close to working but has some remaining problems. Note
6649 that debugging of DOS programs is not supported, due to limitations
6650 in the ``operating system'', but it can be used to host cross-debugging.
6652 * Cross byte order fixes
6654 Many fixes have been made to support cross debugging of Sparc and MIPS
6655 targets from hosts whose byte order differs.
6657 * New -mapped and -readnow options
6659 If memory-mapped files are available on your system through the 'mmap'
6660 system call, you can use the -mapped option on the `file' or
6661 `symbol-file' commands to cause GDB to write the symbols from your
6662 program into a reusable file. If the program you are debugging is
6663 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6664 Future GDB debugging sessions will notice the presence of this file,
6665 and will quickly map in symbol information from it, rather than reading
6666 the symbol table from the executable program. Using the '-mapped'
6667 option in a GDB `file' or `symbol-file' command has the same effect as
6668 starting GDB with the '-mapped' command-line option.
6670 You can cause GDB to read the entire symbol table immediately by using
6671 the '-readnow' option with any of the commands that load symbol table
6672 information (or on the GDB command line). This makes the command
6673 slower, but makes future operations faster.
6675 The -mapped and -readnow options are typically combined in order to
6676 build a `fred.syms' file that contains complete symbol information.
6677 A simple GDB invocation to do nothing but build a `.syms' file for future
6680 gdb -batch -nx -mapped -readnow programname
6682 The `.syms' file is specific to the host machine on which GDB is run.
6683 It holds an exact image of GDB's internal symbol table. It cannot be
6684 shared across multiple host platforms.
6686 * longjmp() handling
6688 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6689 siglongjmp() without losing control. This feature has not yet been ported to
6690 all systems. It currently works on many 386 platforms, all MIPS-based
6691 platforms (SGI, DECstation, etc), and Sun3/4.
6695 Preliminary work has been put in to support the new Solaris OS from Sun. At
6696 this time, it can control and debug processes, but it is not capable of
6701 As always, many many bug fixes. The major areas were with g++, and mipsread.
6702 People using the MIPS-based platforms should experience fewer mysterious
6703 crashes and trashed symbol tables.
6705 *** Changes in GDB-4.4:
6707 * New machines supported (host and target)
6709 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6711 BSD Reno on Vax vax-dec-bsd
6712 Ultrix on Vax vax-dec-ultrix
6714 * New machines supported (target)
6716 AMD 29000 embedded, using EBMON a29k-none-none
6720 GDB continues to improve its handling of C++. `References' work better.
6721 The demangler has also been improved, and now deals with symbols mangled as
6722 per the Annotated C++ Reference Guide.
6724 GDB also now handles `stabs' symbol information embedded in MIPS
6725 `ecoff' symbol tables. Since the ecoff format was not easily
6726 extensible to handle new languages such as C++, this appeared to be a
6727 good way to put C++ debugging info into MIPS binaries. This option
6728 will be supported in the GNU C compiler, version 2, when it is
6731 * New features for SVR4
6733 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6734 shared libraries. Debugging dynamically linked programs should present
6735 only minor differences from debugging statically linked programs.
6737 The `info proc' command will print out information about any process
6738 on an SVR4 system (including the one you are debugging). At the moment,
6739 it prints the address mappings of the process.
6741 If you bring up GDB on another SVR4 system, please send mail to
6742 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6744 * Better dynamic linking support in SunOS
6746 Reading symbols from shared libraries which contain debugging symbols
6747 now works properly. However, there remain issues such as automatic
6748 skipping of `transfer vector' code during function calls, which
6749 make it harder to debug code in a shared library, than to debug the
6750 same code linked statically.
6754 GDB is now using the latest `getopt' routines from the FSF. This
6755 version accepts the -- prefix for options with long names. GDB will
6756 continue to accept the old forms (-option and +option) as well.
6757 Various single letter abbreviations for options have been explicity
6758 added to the option table so that they won't get overshadowed in the
6759 future by other options that begin with the same letter.
6763 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6764 Many assorted bugs have been handled. Many more remain to be handled.
6765 See the various ChangeLog files (primarily in gdb and bfd) for details.
6768 *** Changes in GDB-4.3:
6770 * New machines supported (host and target)
6772 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6773 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6774 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6776 * Almost SCO Unix support
6778 We had hoped to support:
6779 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6780 (except for core file support), but we discovered very late in the release
6781 that it has problems with process groups that render gdb unusable. Sorry
6782 about that. I encourage people to fix it and post the fixes.
6784 * Preliminary ELF and DWARF support
6786 GDB can read ELF object files on System V Release 4, and can handle
6787 debugging records for C, in DWARF format, in ELF files. This support
6788 is preliminary. If you bring up GDB on another SVR4 system, please
6789 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6794 GDB now uses the latest `readline' library. One user-visible change
6795 is that two tabs will list possible command completions, which previously
6796 required typing M-? (meta-question mark, or ESC ?).
6800 The `stepi' bug that many of you noticed has been squashed.
6801 Many bugs in C++ have been handled. Many more remain to be handled.
6802 See the various ChangeLog files (primarily in gdb and bfd) for details.
6804 * State of the MIPS world (in case you wondered):
6806 GDB can understand the symbol tables emitted by the compilers
6807 supplied by most vendors of MIPS-based machines, including DEC. These
6808 symbol tables are in a format that essentially nobody else uses.
6810 Some versions of gcc come with an assembler post-processor called
6811 mips-tfile. This program is required if you want to do source-level
6812 debugging of gcc-compiled programs. I believe FSF does not ship
6813 mips-tfile with gcc version 1, but it will eventually come with gcc
6816 Debugging of g++ output remains a problem. g++ version 1.xx does not
6817 really support it at all. (If you're lucky, you should be able to get
6818 line numbers and stack traces to work, but no parameters or local
6819 variables.) With some work it should be possible to improve the
6822 When gcc version 2 is released, you will have somewhat better luck.
6823 However, even then you will get confusing results for inheritance and
6826 We will eventually provide full debugging of g++ output on
6827 DECstations. This will probably involve some kind of stabs-in-ecoff
6828 encapulation, but the details have not been worked out yet.
6831 *** Changes in GDB-4.2:
6833 * Improved configuration
6835 Only one copy of `configure' exists now, and it is not self-modifying.
6836 Porting BFD is simpler.
6840 The `step' and `next' commands now only stop at the first instruction
6841 of a source line. This prevents the multiple stops that used to occur
6842 in switch statements, for-loops, etc. `Step' continues to stop if a
6843 function that has debugging information is called within the line.
6847 Lots of small bugs fixed. More remain.
6849 * New host supported (not target)
6851 Intel 386 PC clone running Mach i386-none-mach
6854 *** Changes in GDB-4.1:
6856 * Multiple source language support
6858 GDB now has internal scaffolding to handle several source languages.
6859 It determines the type of each source file from its filename extension,
6860 and will switch expression parsing and number formatting to match the
6861 language of the function in the currently selected stack frame.
6862 You can also specifically set the language to be used, with
6863 `set language c' or `set language modula-2'.
6867 GDB now has preliminary support for the GNU Modula-2 compiler,
6868 currently under development at the State University of New York at
6869 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6870 continue through the fall of 1991 and into 1992.
6872 Other Modula-2 compilers are currently not supported, and attempting to
6873 debug programs compiled with them will likely result in an error as the
6874 symbol table is read. Feel free to work on it, though!
6876 There are hooks in GDB for strict type checking and range checking,
6877 in the `Modula-2 philosophy', but they do not currently work.
6881 GDB can now write to executable and core files (e.g. patch
6882 a variable's value). You must turn this switch on, specify
6883 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6884 by assigning a new value to a variable. Modifications take
6887 * Automatic SunOS shared library reading
6889 When you run your program, GDB automatically determines where its
6890 shared libraries (if any) have been loaded, and reads their symbols.
6891 The `share' command is no longer needed. This also works when
6892 examining core files.
6896 You can specify the number of lines that the `list' command shows.
6899 * New machines supported (host and target)
6901 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6902 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6903 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6905 * New hosts supported (not targets)
6907 IBM RT/PC: romp-ibm-aix or rtpc
6909 * New targets supported (not hosts)
6911 AMD 29000 embedded with COFF a29k-none-coff
6912 AMD 29000 embedded with a.out a29k-none-aout
6913 Ultracomputer remote kernel debug a29k-nyu-kern
6915 * New remote interfaces
6921 *** Changes in GDB-4.0:
6925 Wide output is wrapped at good places to make the output more readable.
6927 Gdb now supports cross-debugging from a host machine of one type to a
6928 target machine of another type. Communication with the target system
6929 is over serial lines. The ``target'' command handles connecting to the
6930 remote system; the ``load'' command will download a program into the
6931 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6932 also supports debugging of realtime processes running under VxWorks,
6933 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6934 stub on the target system.
6936 New CPUs supported include the AMD 29000 and Intel 960.
6938 GDB now reads object files and symbol tables via a ``binary file''
6939 library, which allows a single copy of GDB to debug programs of multiple
6940 object file types such as a.out and coff.
6942 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6943 refcard.dvi and refcard.ps are available to format it).
6946 * Control-Variable user interface simplified
6948 All variables that control the operation of the debugger can be set
6949 by the ``set'' command, and displayed by the ``show'' command.
6951 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6952 ``Show prompt'' produces the response:
6953 Gdb's prompt is new-gdb=>.
6955 What follows are the NEW set commands. The command ``help set'' will
6956 print a complete list of old and new set commands. ``help set FOO''
6957 will give a longer description of the variable FOO. ``show'' will show
6958 all of the variable descriptions and their current settings.
6960 confirm on/off: Enables warning questions for operations that are
6961 hard to recover from, e.g. rerunning the program while
6962 it is already running. Default is ON.
6964 editing on/off: Enables EMACS style command line editing
6965 of input. Previous lines can be recalled with
6966 control-P, the current line can be edited with control-B,
6967 you can search for commands with control-R, etc.
6970 history filename NAME: NAME is where the gdb command history
6971 will be stored. The default is .gdb_history,
6972 or the value of the environment variable
6975 history size N: The size, in commands, of the command history. The
6976 default is 256, or the value of the environment variable
6979 history save on/off: If this value is set to ON, the history file will
6980 be saved after exiting gdb. If set to OFF, the
6981 file will not be saved. The default is OFF.
6983 history expansion on/off: If this value is set to ON, then csh-like
6984 history expansion will be performed on
6985 command line input. The default is OFF.
6987 radix N: Sets the default radix for input and output. It can be set
6988 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6989 in the current radix, so "set radix 10" is always a no-op.
6991 height N: This integer value is the number of lines on a page. Default
6992 is 24, the current `stty rows'' setting, or the ``li#''
6993 setting from the termcap entry matching the environment
6996 width N: This integer value is the number of characters on a line.
6997 Default is 80, the current `stty cols'' setting, or the ``co#''
6998 setting from the termcap entry matching the environment
7001 Note: ``set screensize'' is obsolete. Use ``set height'' and
7002 ``set width'' instead.
7004 print address on/off: Print memory addresses in various command displays,
7005 such as stack traces and structure values. Gdb looks
7006 more ``symbolic'' if you turn this off; it looks more
7007 ``machine level'' with it on. Default is ON.
7009 print array on/off: Prettyprint arrays. New convenient format! Default
7012 print demangle on/off: Print C++ symbols in "source" form if on,
7015 print asm-demangle on/off: Same, for assembler level printouts
7018 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7021 * Support for Epoch Environment.
7023 The epoch environment is a version of Emacs v18 with windowing. One
7024 new command, ``inspect'', is identical to ``print'', except that if you
7025 are running in the epoch environment, the value is printed in its own
7029 * Support for Shared Libraries
7031 GDB can now debug programs and core files that use SunOS shared libraries.
7032 Symbols from a shared library cannot be referenced
7033 before the shared library has been linked with the program (this
7034 happens after you type ``run'' and before the function main() is entered).
7035 At any time after this linking (including when examining core files
7036 from dynamically linked programs), gdb reads the symbols from each
7037 shared library when you type the ``sharedlibrary'' command.
7038 It can be abbreviated ``share''.
7040 sharedlibrary REGEXP: Load shared object library symbols for files
7041 matching a unix regular expression. No argument
7042 indicates to load symbols for all shared libraries.
7044 info sharedlibrary: Status of loaded shared libraries.
7049 A watchpoint stops execution of a program whenever the value of an
7050 expression changes. Checking for this slows down execution
7051 tremendously whenever you are in the scope of the expression, but is
7052 quite useful for catching tough ``bit-spreader'' or pointer misuse
7053 problems. Some machines such as the 386 have hardware for doing this
7054 more quickly, and future versions of gdb will use this hardware.
7056 watch EXP: Set a watchpoint (breakpoint) for an expression.
7058 info watchpoints: Information about your watchpoints.
7060 delete N: Deletes watchpoint number N (same as breakpoints).
7061 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7062 enable N: Re-enables watchpoint number N (same as breakpoints).
7065 * C++ multiple inheritance
7067 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7070 * C++ exception handling
7072 Gdb now supports limited C++ exception handling. Besides the existing
7073 ability to breakpoint on an exception handler, gdb can breakpoint on
7074 the raising of an exception (before the stack is peeled back to the
7077 catch FOO: If there is a FOO exception handler in the dynamic scope,
7078 set a breakpoint to catch exceptions which may be raised there.
7079 Multiple exceptions (``catch foo bar baz'') may be caught.
7081 info catch: Lists all exceptions which may be caught in the
7082 current stack frame.
7085 * Minor command changes
7087 The command ``call func (arg, arg, ...)'' now acts like the print
7088 command, except it does not print or save a value if the function's result
7089 is void. This is similar to dbx usage.
7091 The ``up'' and ``down'' commands now always print the frame they end up
7092 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7093 frames without printing.
7095 * New directory command
7097 'dir' now adds directories to the FRONT of the source search path.
7098 The path starts off empty. Source files that contain debug information
7099 about the directory in which they were compiled can be found even
7100 with an empty path; Sun CC and GCC include this information. If GDB can't
7101 find your source file in the current directory, type "dir .".
7103 * Configuring GDB for compilation
7105 For normal use, type ``./configure host''. See README or gdb.texinfo
7108 GDB now handles cross debugging. If you are remotely debugging between
7109 two different machines, type ``./configure host -target=targ''.
7110 Host is the machine where GDB will run; targ is the machine
7111 where the program that you are debugging will run.