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.
46 ** The '-data-disassemble' MI command now accepts an '-a' option to
47 disassemble the whole function surrounding the given program
48 counter value or function name. Support for this feature can be
49 verified by using the "-list-features" command, which should
50 contain "data-disassemble-a-option".
52 ** Command responses and notifications that include a frame now include
53 the frame's architecture in a new "arch" attribute.
55 * New native configurations
57 GNU/Linux/RISC-V riscv*-*-linux*
61 GNU/Linux/RISC-V riscv*-*-linux*
63 *** Changes in GDB 8.2
65 * The 'set disassembler-options' command now supports specifying options
68 * The 'symbol-file' command now accepts an '-o' option to add a relative
69 offset to all sections.
71 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
72 a relative offset to all sections, but it allows to override the load
73 address of individual sections using '-s'.
75 * The 'add-symbol-file' command no longer requires the second argument
76 (address of the text section).
78 * The endianness used with the 'set endian auto' mode in the absence of
79 an executable selected for debugging is now the last endianness chosen
80 either by one of the 'set endian big' and 'set endian little' commands
81 or by inferring from the last executable used, rather than the startup
84 * The pager now allows a "c" response, meaning to disable the pager
85 for the rest of the current command.
87 * The commands 'info variables/functions/types' now show the source line
88 numbers of symbol definitions when available.
90 * 'info proc' now works on running processes on FreeBSD systems and core
91 files created on FreeBSD systems.
93 * C expressions can now use _Alignof, and C++ expressions can now use
96 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
97 the vector length while the process is running.
103 Control display of debugging info regarding the FreeBSD native target.
105 set|show varsize-limit
106 This new setting allows the user to control the maximum size of Ada
107 objects being printed when those objects have a variable type,
108 instead of that maximum size being hardcoded to 65536 bytes.
110 set|show record btrace cpu
111 Controls the processor to be used for enabling errata workarounds for
114 maint check libthread-db
115 Run integrity checks on the current inferior's thread debugging
118 maint set check-libthread-db (on|off)
119 maint show check-libthread-db
120 Control whether to run integrity checks on inferior specific thread
121 debugging libraries as they are loaded. The default is not to
126 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
128 ** The commands attached to a breakpoint can be set by assigning to
129 the breakpoint's "commands" field.
131 ** gdb.execute can now execute multi-line gdb commands.
133 ** The new functions gdb.convenience_variable and
134 gdb.set_convenience_variable can be used to get and set the value
135 of convenience variables.
137 ** A gdb.Parameter will no longer print the "set" help text on an
138 ordinary "set"; instead by default a "set" will be silent unless
139 the get_set_string method returns a non-empty string.
143 RiscV ELF riscv*-*-elf
145 * Removed targets and native configurations
147 m88k running OpenBSD m88*-*-openbsd*
148 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
149 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
150 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
152 * Aarch64/Linux hardware watchpoints improvements
154 Hardware watchpoints on unaligned addresses are now properly
155 supported when running Linux kernel 4.10 or higher: read and access
156 watchpoints are no longer spuriously missed, and all watchpoints
157 lengths between 1 and 8 bytes are supported. On older kernels,
158 watchpoints set on unaligned addresses are no longer missed, with
159 the tradeoff that there is a possibility of false hits being
164 --enable-codesign=CERT
165 This can be used to invoke "codesign -s CERT" after building gdb.
166 This option is useful on macOS, where code signing is required for
167 gdb to work properly.
169 --disable-gdbcli has been removed
170 This is now silently accepted, but does nothing.
172 *** Changes in GDB 8.1
174 * GDB now supports dynamically creating arbitrary register groups specified
175 in XML target descriptions. This allows for finer grain grouping of
176 registers on systems with a large amount of registers.
178 * The 'ptype' command now accepts a '/o' flag, which prints the
179 offsets and sizes of fields in a struct, like the pahole(1) tool.
181 * New "--readnever" command line option instructs GDB to not read each
182 symbol file's symbolic debug information. This makes startup faster
183 but at the expense of not being able to perform symbolic debugging.
184 This option is intended for use cases where symbolic debugging will
185 not be used, e.g., when you only need to dump the debuggee's core.
187 * GDB now uses the GNU MPFR library, if available, to emulate target
188 floating-point arithmetic during expression evaluation when the target
189 uses different floating-point formats than the host. At least version
190 3.1 of GNU MPFR is required.
192 * GDB now supports access to the guarded-storage-control registers and the
193 software-based guarded-storage broadcast control registers on IBM z14.
195 * On Unix systems, GDB now supports transmitting environment variables
196 that are to be set or unset to GDBserver. These variables will
197 affect the environment to be passed to the remote inferior.
199 To inform GDB of environment variables that are to be transmitted to
200 GDBserver, use the "set environment" command. Only user set
201 environment variables are sent to GDBserver.
203 To inform GDB of environment variables that are to be unset before
204 the remote inferior is started by the GDBserver, use the "unset
205 environment" command.
207 * Completion improvements
209 ** GDB can now complete function parameters in linespecs and
210 explicit locations without quoting. When setting breakpoints,
211 quoting around functions names to help with TAB-completion is
212 generally no longer necessary. For example, this now completes
215 (gdb) b function(in[TAB]
216 (gdb) b function(int)
218 Related, GDB is no longer confused with completing functions in
219 C++ anonymous namespaces:
222 (gdb) b (anonymous namespace)::[TAB][TAB]
223 (anonymous namespace)::a_function()
224 (anonymous namespace)::b_function()
226 ** GDB now has much improved linespec and explicit locations TAB
227 completion support, that better understands what you're
228 completing and offers better suggestions. For example, GDB no
229 longer offers data symbols as possible completions when you're
230 setting a breakpoint.
232 ** GDB now TAB-completes label symbol names.
234 ** The "complete" command now mimics TAB completion accurately.
236 * New command line options (gcore)
239 Dump all memory mappings.
241 * Breakpoints on C++ functions are now set on all scopes by default
243 By default, breakpoints on functions/methods are now interpreted as
244 specifying all functions with the given name ignoring missing
245 leading scopes (namespaces and classes).
247 For example, assuming a C++ program with symbols named:
252 both commands "break func()" and "break B::func()" set a breakpoint
255 You can use the new flag "-qualified" to override this. This makes
256 GDB interpret the specified function name as a complete
257 fully-qualified name instead. For example, using the same C++
258 program, the "break -q B::func" command sets a breakpoint on
259 "B::func", only. A parameter has been added to the Python
260 gdb.Breakpoint constructor to achieve the same result when creating
261 a breakpoint from Python.
263 * Breakpoints on functions marked with C++ ABI tags
265 GDB can now set breakpoints on functions marked with C++ ABI tags
266 (e.g., [abi:cxx11]). See here for a description of ABI tags:
267 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
269 Functions with a C++11 abi tag are demangled/displayed like this:
271 function[abi:cxx11](int)
274 You can now set a breakpoint on such functions simply as if they had
277 (gdb) b function(int)
279 Or if you need to disambiguate between tags, like:
281 (gdb) b function[abi:other_tag](int)
283 Tab completion was adjusted accordingly as well.
287 ** New events gdb.new_inferior, gdb.inferior_deleted, and
288 gdb.new_thread are emitted. See the manual for further
289 description of these.
291 ** A new function, "gdb.rbreak" has been added to the Python API.
292 This function allows the setting of a large number of breakpoints
293 via a regex pattern in Python. See the manual for further details.
295 ** Python breakpoints can now accept explicit locations. See the
296 manual for a further description of this feature.
299 * New features in the GDB remote stub, GDBserver
301 ** GDBserver is now able to start inferior processes with a
302 specified initial working directory.
304 The user can set the desired working directory to be used from
305 GDB using the new "set cwd" command.
307 ** New "--selftest" command line option runs some GDBserver self
308 tests. These self tests are disabled in releases.
310 ** On Unix systems, GDBserver now does globbing expansion and variable
311 substitution in inferior command line arguments.
313 This is done by starting inferiors using a shell, like GDB does.
314 See "set startup-with-shell" in the user manual for how to disable
315 this from GDB when using "target extended-remote". When using
316 "target remote", you can disable the startup with shell by using the
317 new "--no-startup-with-shell" GDBserver command line option.
319 ** On Unix systems, GDBserver now supports receiving environment
320 variables that are to be set or unset from GDB. These variables
321 will affect the environment to be passed to the inferior.
323 * When catching an Ada exception raised with a message, GDB now prints
324 the message in the catchpoint hit notification. In GDB/MI mode, that
325 information is provided as an extra field named "exception-message"
326 in the *stopped notification.
328 * Trait objects can now be inspected When debugging Rust code. This
329 requires compiler support which will appear in Rust 1.24.
333 QEnvironmentHexEncoded
334 Inform GDBserver of an environment variable that is to be passed to
335 the inferior when starting it.
338 Inform GDBserver of an environment variable that is to be unset
339 before starting the remote inferior.
342 Inform GDBserver that the environment should be reset (i.e.,
343 user-set environment variables should be unset).
346 Indicates whether the inferior must be started with a shell or not.
349 Tell GDBserver that the inferior to be started should use a specific
352 * The "maintenance print c-tdesc" command now takes an optional
353 argument which is the file name of XML target description.
355 * The "maintenance selftest" command now takes an optional argument to
356 filter the tests to be run.
358 * The "enable", and "disable" commands now accept a range of
359 breakpoint locations, e.g. "enable 1.3-5".
364 Set and show the current working directory for the inferior.
367 Set and show compilation command used for compiling and injecting code
368 with the 'compile' commands.
370 set debug separate-debug-file
371 show debug separate-debug-file
372 Control the display of debug output about separate debug file search.
374 set dump-excluded-mappings
375 show dump-excluded-mappings
376 Control whether mappings marked with the VM_DONTDUMP flag should be
377 dumped when generating a core file.
380 List the registered selftests.
383 Start the debugged program stopping at the first instruction.
386 Control display of debugging messages related to OpenRISC targets.
388 set|show print type nested-type-limit
389 Set and show the limit of nesting level for nested types that the
390 type printer will show.
392 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
395 * Safer/improved support for debugging with no debug info
397 GDB no longer assumes functions with no debug information return
400 This means that GDB now refuses to call such functions unless you
401 tell it the function's type, by either casting the call to the
402 declared return type, or by casting the function to a function
403 pointer of the right type, and calling that:
405 (gdb) p getenv ("PATH")
406 'getenv' has unknown return type; cast the call to its declared return type
407 (gdb) p (char *) getenv ("PATH")
408 $1 = 0x7fffffffe "/usr/local/bin:/"...
409 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
410 $2 = 0x7fffffffe "/usr/local/bin:/"...
412 Similarly, GDB no longer assumes that global variables with no debug
413 info have type 'int', and refuses to print the variable's value
414 unless you tell it the variable's type:
417 'var' has unknown type; cast it to its declared type
421 * New native configurations
423 FreeBSD/aarch64 aarch64*-*-freebsd*
424 FreeBSD/arm arm*-*-freebsd*
428 FreeBSD/aarch64 aarch64*-*-freebsd*
429 FreeBSD/arm arm*-*-freebsd*
430 OpenRISC ELF or1k*-*-elf
432 * Removed targets and native configurations
434 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
436 *** Changes in GDB 8.0
438 * GDB now supports access to the PKU register on GNU/Linux. The register is
439 added by the Memory Protection Keys for Userspace feature which will be
440 available in future Intel CPUs.
442 * GDB now supports C++11 rvalue references.
446 ** New functions to start, stop and access a running btrace recording.
447 ** Rvalue references are now supported in gdb.Type.
449 * GDB now supports recording and replaying rdrand and rdseed Intel 64
452 * Building GDB and GDBserver now requires a C++11 compiler.
454 For example, GCC 4.8 or later.
456 It is no longer possible to build GDB or GDBserver with a C
457 compiler. The --disable-build-with-cxx configure option has been
460 * Building GDB and GDBserver now requires GNU make >= 3.81.
462 It is no longer supported to build GDB or GDBserver with another
463 implementation of the make program or an earlier version of GNU make.
465 * Native debugging on MS-Windows supports command-line redirection
467 Command-line arguments used for starting programs on MS-Windows can
468 now include redirection symbols supported by native Windows shells,
469 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
470 as "run", "start", and "set args", as well as the corresponding MI
473 * Support for thread names on MS-Windows.
475 GDB now catches and handles the special exception that programs
476 running on MS-Windows use to assign names to threads in the
479 * Support for Java programs compiled with gcj has been removed.
481 * User commands now accept an unlimited number of arguments.
482 Previously, only up to 10 was accepted.
484 * The "eval" command now expands user-defined command arguments.
486 This makes it easier to process a variable number of arguments:
491 eval "print $arg%d", $i
496 * Target descriptions can now describe registers for sparc32 and sparc64.
498 * GDB now supports DWARF version 5 (debug information format).
499 Its .debug_names index is not yet supported.
501 * New native configurations
503 FreeBSD/mips mips*-*-freebsd
507 Synopsys ARC arc*-*-elf32
508 FreeBSD/mips mips*-*-freebsd
510 * Removed targets and native configurations
512 Alpha running FreeBSD alpha*-*-freebsd*
513 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
518 Erases all the flash memory regions reported by the target.
520 maint print arc arc-instruction address
521 Print internal disassembler information about instruction at a given address.
525 set disassembler-options
526 show disassembler-options
527 Controls the passing of target specific information to the disassembler.
528 If it is necessary to specify more than one disassembler option then
529 multiple options can be placed together into a comma separated list.
530 The default value is the empty string. Currently, the only supported
531 targets are ARM, PowerPC and S/390.
536 Erases all the flash memory regions reported by the target. This is
537 equivalent to the CLI command flash-erase.
539 -file-list-shared-libraries
540 List the shared libraries in the program. This is
541 equivalent to the CLI command "info shared".
544 Catchpoints stopping the program when Ada exceptions are
545 handled. This is equivalent to the CLI command "catch handlers".
547 *** Changes in GDB 7.12
549 * GDB and GDBserver now build with a C++ compiler by default.
551 The --enable-build-with-cxx configure option is now enabled by
552 default. One must now explicitly configure with
553 --disable-build-with-cxx in order to build with a C compiler. This
554 option will be removed in a future release.
556 * GDBserver now supports recording btrace without maintaining an active
559 * GDB now supports a negative repeat count in the 'x' command to examine
560 memory backward from the given address. For example:
563 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
564 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
565 (gdb) x/-5i 0x0000000000400580
566 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
567 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
568 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
569 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
570 0x40057b <main(int, char**)+25>:
571 callq 0x400536 <Func1(int, char const*)>
573 * Fortran: Support structures with fields of dynamic types and
574 arrays of dynamic types.
576 * The symbol dumping maintenance commands have new syntax.
577 maint print symbols [-pc address] [--] [filename]
578 maint print symbols [-objfile objfile] [-source source] [--] [filename]
579 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
580 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
581 maint print msymbols [-objfile objfile] [--] [filename]
583 * GDB now supports multibit bitfields and enums in target register
586 * New Python-based convenience function $_as_string(val), which returns
587 the textual representation of a value. This function is especially
588 useful to obtain the text label of an enum value.
590 * Intel MPX bound violation handling.
592 Segmentation faults caused by a Intel MPX boundary violation
593 now display the kind of violation (upper or lower), the memory
594 address accessed and the memory bounds, along with the usual
595 signal received and code location.
599 Program received signal SIGSEGV, Segmentation fault
600 Upper bound violation while accessing address 0x7fffffffc3b3
601 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
602 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
604 * Rust language support.
605 GDB now supports debugging programs written in the Rust programming
606 language. See https://www.rust-lang.org/ for more information about
609 * Support for running interpreters on specified input/output devices
611 GDB now supports a new mechanism that allows frontends to provide
612 fully featured GDB console views, as a better alternative to
613 building such views on top of the "-interpreter-exec console"
614 command. See the new "new-ui" command below. With that command,
615 frontends can now start GDB in the traditional command-line mode
616 running in an embedded terminal emulator widget, and create a
617 separate MI interpreter running on a specified i/o device. In this
618 way, GDB handles line editing, history, tab completion, etc. in the
619 console all by itself, and the GUI uses the separate MI interpreter
620 for its own control and synchronization, invisible to the command
623 * The "catch syscall" command catches groups of related syscalls.
625 The "catch syscall" command now supports catching a group of related
626 syscalls using the 'group:' or 'g:' prefix.
631 skip -gfile file-glob-pattern
632 skip -function function
633 skip -rfunction regular-expression
634 A generalized form of the skip command, with new support for
635 glob-style file names and regular expressions for function names.
636 Additionally, a file spec and a function spec may now be combined.
638 maint info line-table REGEXP
639 Display the contents of GDB's internal line table data struture.
642 Run any GDB unit tests that were compiled in.
645 Start a new user interface instance running INTERP as interpreter,
646 using the TTY file for input/output.
650 ** gdb.Breakpoint objects have a new attribute "pending", which
651 indicates whether the breakpoint is pending.
652 ** Three new breakpoint-related events have been added:
653 gdb.breakpoint_created, gdb.breakpoint_modified, and
654 gdb.breakpoint_deleted.
657 Signal ("set") the given MS-Windows event object. This is used in
658 conjunction with the Windows JIT debugging (AeDebug) support, where
659 the OS suspends a crashing process until a debugger can attach to
660 it. Resuming the crashing process, in order to debug it, is done by
663 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
664 was added in GDBserver, including JIT compiling fast tracepoint's
665 conditional expression bytecode into native code.
667 * Support for various remote target protocols and ROM monitors has
670 target m32rsdi Remote M32R debugging over SDI
671 target mips MIPS remote debugging protocol
672 target pmon PMON ROM monitor
673 target ddb NEC's DDB variant of PMON for Vr4300
674 target rockhopper NEC RockHopper variant of PMON
675 target lsi LSI variant of PMO
677 * Support for tracepoints and fast tracepoints on powerpc-linux,
678 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
679 including JIT compiling fast tracepoint's conditional expression
680 bytecode into native code.
682 * MI async record =record-started now includes the method and format used for
683 recording. For example:
685 =record-started,thread-group="i1",method="btrace",format="bts"
687 * MI async record =thread-selected now includes the frame field. For example:
689 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
693 Andes NDS32 nds32*-*-elf
695 *** Changes in GDB 7.11
697 * GDB now supports debugging kernel-based threads on FreeBSD.
699 * Per-inferior thread numbers
701 Thread numbers are now per inferior instead of global. If you're
702 debugging multiple inferiors, GDB displays thread IDs using a
703 qualified INF_NUM.THR_NUM form. For example:
707 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
708 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
709 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
710 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
712 As consequence, thread numbers as visible in the $_thread
713 convenience variable and in Python's InferiorThread.num attribute
714 are no longer unique between inferiors.
716 GDB now maintains a second thread ID per thread, referred to as the
717 global thread ID, which is the new equivalent of thread numbers in
718 previous releases. See also $_gthread below.
720 For backwards compatibility, MI's thread IDs always refer to global
723 * Commands that accept thread IDs now accept the qualified
724 INF_NUM.THR_NUM form as well. For example:
727 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
730 * In commands that accept a list of thread IDs, you can now refer to
731 all threads of an inferior using a star wildcard. GDB accepts
732 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
733 refer to all threads of the current inferior. For example, "info
736 * You can use "info threads -gid" to display the global thread ID of
739 * The new convenience variable $_gthread holds the global number of
742 * The new convenience variable $_inferior holds the number of the
745 * GDB now displays the ID and name of the thread that hit a breakpoint
746 or received a signal, if your program is multi-threaded. For
749 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
750 Thread 1 "main" received signal SIGINT, Interrupt.
752 * Record btrace now supports non-stop mode.
754 * Support for tracepoints on aarch64-linux was added in GDBserver.
756 * The 'record instruction-history' command now indicates speculative execution
757 when using the Intel Processor Trace recording format.
759 * GDB now allows users to specify explicit locations, bypassing
760 the linespec parser. This feature is also available to GDB/MI
763 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
764 GDB now is able to debug both AArch64 applications and ARM applications
767 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
768 including JIT compiling fast tracepoint's conditional expression bytecode
771 * GDB now supports displaced stepping on AArch64 GNU/Linux.
773 * "info threads", "info inferiors", "info display", "info checkpoints"
774 and "maint info program-spaces" now list the corresponding items in
775 ascending ID order, for consistency with all other "info" commands.
777 * In Ada, the overloads selection menu has been enhanced to display the
778 parameter types and the return types for the matching overloaded subprograms.
782 maint set target-non-stop (on|off|auto)
783 maint show target-non-stop
784 Control whether GDB targets always operate in non-stop mode even if
785 "set non-stop" is "off". The default is "auto", meaning non-stop
786 mode is enabled if supported by the target.
788 maint set bfd-sharing
789 maint show bfd-sharing
790 Control the reuse of bfd objects.
794 Control display of debugging info regarding bfd caching.
798 Control display of debugging info regarding FreeBSD threads.
800 set remote multiprocess-extensions-packet
801 show remote multiprocess-extensions-packet
802 Set/show the use of the remote protocol multiprocess extensions.
804 set remote thread-events
805 show remote thread-events
806 Set/show the use of thread create/exit events.
808 set ada print-signatures on|off
809 show ada print-signatures"
810 Control whether parameter types and return types are displayed in overloads
811 selection menus. It is activaled (@code{on}) by default.
815 Controls the maximum size of memory, in bytes, that GDB will
816 allocate for value contents. Prevents incorrect programs from
817 causing GDB to allocate overly large buffers. Default is 64k.
819 * The "disassemble" command accepts a new modifier: /s.
820 It prints mixed source+disassembly like /m with two differences:
821 - disassembled instructions are now printed in program order, and
822 - and source for all relevant files is now printed.
823 The "/m" option is now considered deprecated: its "source-centric"
824 output hasn't proved useful in practice.
826 * The "record instruction-history" command accepts a new modifier: /s.
827 It behaves exactly like /m and prints mixed source+disassembly.
829 * The "set scheduler-locking" command supports a new mode "replay".
830 It behaves like "off" in record mode and like "on" in replay mode.
832 * Support for various ROM monitors has been removed:
834 target dbug dBUG ROM monitor for Motorola ColdFire
835 target picobug Motorola picobug monitor
836 target dink32 DINK32 ROM monitor for PowerPC
837 target m32r Renesas M32R/D ROM monitor
838 target mon2000 mon2000 ROM monitor
839 target ppcbug PPCBUG ROM monitor for PowerPC
841 * Support for reading/writing memory and extracting values on architectures
842 whose memory is addressable in units of any integral multiple of 8 bits.
845 Allows to break when an Ada exception is handled.
850 Indicates that an exec system call was executed.
852 exec-events feature in qSupported
853 The qSupported packet allows GDB to request support for exec
854 events using the new 'gdbfeature' exec-event, and the qSupported
855 response can contain the corresponding 'stubfeature'. Set and
856 show commands can be used to display whether these features are enabled.
859 Equivalent to interrupting with the ^C character, but works in
862 thread created stop reason (T05 create:...)
863 Indicates that the thread was just created and is stopped at entry.
865 thread exit stop reply (w exitcode;tid)
866 Indicates that the thread has terminated.
869 Enables/disables thread create and exit event reporting. For
870 example, this is used in non-stop mode when GDB stops a set of
871 threads and synchronously waits for the their corresponding stop
872 replies. Without exit events, if one of the threads exits, GDB
873 would hang forever not knowing that it should no longer expect a
874 stop for that same thread.
877 Indicates that there are no resumed threads left in the target (all
878 threads are stopped). The remote stub reports support for this stop
879 reply to GDB's qSupported query.
882 Enables/disables catching syscalls from the inferior process.
883 The remote stub reports support for this packet to GDB's qSupported query.
885 syscall_entry stop reason
886 Indicates that a syscall was just called.
888 syscall_return stop reason
889 Indicates that a syscall just returned.
891 * Extended-remote exec events
893 ** GDB now has support for exec events on extended-remote Linux targets.
894 For such targets with Linux kernels 2.5.46 and later, this enables
895 follow-exec-mode and exec catchpoints.
897 set remote exec-event-feature-packet
898 show remote exec-event-feature-packet
899 Set/show the use of the remote exec event feature.
901 * Thread names in remote protocol
903 The reply to qXfer:threads:read may now include a name attribute for each
906 * Target remote mode fork and exec events
908 ** GDB now has support for fork and exec events on target remote mode
909 Linux targets. For such targets with Linux kernels 2.5.46 and later,
910 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
911 fork and exec catchpoints.
913 * Remote syscall events
915 ** GDB now has support for catch syscall on remote Linux targets,
916 currently enabled on x86/x86_64 architectures.
918 set remote catch-syscall-packet
919 show remote catch-syscall-packet
920 Set/show the use of the remote catch syscall feature.
924 ** The -var-set-format command now accepts the zero-hexadecimal
925 format. It outputs data in hexadecimal format with zero-padding on the
930 ** gdb.InferiorThread objects have a new attribute "global_num",
931 which refers to the thread's global thread ID. The existing
932 "num" attribute now refers to the thread's per-inferior number.
933 See "Per-inferior thread numbers" above.
934 ** gdb.InferiorThread objects have a new attribute "inferior", which
935 is the Inferior object the thread belongs to.
937 *** Changes in GDB 7.10
939 * Support for process record-replay and reverse debugging on aarch64*-linux*
940 targets has been added. GDB now supports recording of A64 instruction set
941 including advance SIMD instructions.
943 * Support for Sun's version of the "stabs" debug file format has been removed.
945 * GDB now honors the content of the file /proc/PID/coredump_filter
946 (PID is the process ID) on GNU/Linux systems. This file can be used
947 to specify the types of memory mappings that will be included in a
948 corefile. For more information, please refer to the manual page of
949 "core(5)". GDB also has a new command: "set use-coredump-filter
950 on|off". It allows to set whether GDB will read the content of the
951 /proc/PID/coredump_filter file when generating a corefile.
953 * The "info os" command on GNU/Linux can now display information on
955 "info os cpus" Listing of all cpus/cores on the system
957 * GDB has two new commands: "set serial parity odd|even|none" and
958 "show serial parity". These allows to set or show parity for the
961 * The "info source" command now displays the producer string if it was
962 present in the debug info. This typically includes the compiler version
963 and may include things like its command line arguments.
965 * The "info dll", an alias of the "info sharedlibrary" command,
966 is now available on all platforms.
968 * Directory names supplied to the "set sysroot" commands may be
969 prefixed with "target:" to tell GDB to access shared libraries from
970 the target system, be it local or remote. This replaces the prefix
971 "remote:". The default sysroot has been changed from "" to
972 "target:". "remote:" is automatically converted to "target:" for
973 backward compatibility.
975 * The system root specified by "set sysroot" will be prepended to the
976 filename of the main executable (if reported to GDB as absolute by
977 the operating system) when starting processes remotely, and when
978 attaching to already-running local or remote processes.
980 * GDB now supports automatic location and retrieval of executable
981 files from remote targets. Remote debugging can now be initiated
982 using only a "target remote" or "target extended-remote" command
983 (no "set sysroot" or "file" commands are required). See "New remote
986 * The "dump" command now supports verilog hex format.
988 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
990 * On GNU/Linux, GDB and gdbserver are now able to access executable
991 and shared library files without a "set sysroot" command when
992 attaching to processes running in different mount namespaces from
993 the debugger. This makes it possible to attach to processes in
994 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
995 See "New remote packets" below.
997 * The "tui reg" command now provides completion for all of the
998 available register groups, including target specific groups.
1000 * The HISTSIZE environment variable is no longer read when determining
1001 the size of GDB's command history. GDB now instead reads the dedicated
1002 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1003 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1008 ** Memory ports can now be unbuffered.
1012 ** gdb.Objfile objects have a new attribute "username",
1013 which is the name of the objfile as specified by the user,
1014 without, for example, resolving symlinks.
1015 ** You can now write frame unwinders in Python.
1016 ** gdb.Type objects have a new method "optimized_out",
1017 returning optimized out gdb.Value instance of this type.
1018 ** gdb.Value objects have new methods "reference_value" and
1019 "const_value" which return a reference to the value and a
1020 "const" version of the value respectively.
1024 maint print symbol-cache
1025 Print the contents of the symbol cache.
1027 maint print symbol-cache-statistics
1028 Print statistics of symbol cache usage.
1030 maint flush-symbol-cache
1031 Flush the contents of the symbol cache.
1035 Start branch trace recording using Branch Trace Store (BTS) format.
1038 Evaluate expression by using the compiler and print result.
1042 Explicit commands for enabling and disabling tui mode.
1045 set mpx bound on i386 and amd64
1046 Support for bound table investigation on Intel MPX enabled applications.
1050 Start branch trace recording using Intel Processor Trace format.
1053 Print information about branch tracing internals.
1055 maint btrace packet-history
1056 Print the raw branch tracing data.
1058 maint btrace clear-packet-history
1059 Discard the stored raw branch tracing data.
1062 Discard all branch tracing data. It will be fetched and processed
1063 anew by the next "record" command.
1068 Renamed from "set debug dwarf2-die".
1069 show debug dwarf-die
1070 Renamed from "show debug dwarf2-die".
1072 set debug dwarf-read
1073 Renamed from "set debug dwarf2-read".
1074 show debug dwarf-read
1075 Renamed from "show debug dwarf2-read".
1077 maint set dwarf always-disassemble
1078 Renamed from "maint set dwarf2 always-disassemble".
1079 maint show dwarf always-disassemble
1080 Renamed from "maint show dwarf2 always-disassemble".
1082 maint set dwarf max-cache-age
1083 Renamed from "maint set dwarf2 max-cache-age".
1084 maint show dwarf max-cache-age
1085 Renamed from "maint show dwarf2 max-cache-age".
1087 set debug dwarf-line
1088 show debug dwarf-line
1089 Control display of debugging info regarding DWARF line processing.
1092 show max-completions
1093 Set the maximum number of candidates to be considered during
1094 completion. The default value is 200. This limit allows GDB
1095 to avoid generating large completion lists, the computation of
1096 which can cause the debugger to become temporarily unresponsive.
1098 set history remove-duplicates
1099 show history remove-duplicates
1100 Control the removal of duplicate history entries.
1102 maint set symbol-cache-size
1103 maint show symbol-cache-size
1104 Control the size of the symbol cache.
1106 set|show record btrace bts buffer-size
1107 Set and show the size of the ring buffer used for branch tracing in
1109 The obtained size may differ from the requested size. Use "info
1110 record" to see the obtained buffer size.
1112 set debug linux-namespaces
1113 show debug linux-namespaces
1114 Control display of debugging info regarding Linux namespaces.
1116 set|show record btrace pt buffer-size
1117 Set and show the size of the ring buffer used for branch tracing in
1118 Intel Processor Trace format.
1119 The obtained size may differ from the requested size. Use "info
1120 record" to see the obtained buffer size.
1122 maint set|show btrace pt skip-pad
1123 Set and show whether PAD packets are skipped when computing the
1126 * The command 'thread apply all' can now support new option '-ascending'
1127 to call its specified command for all threads in ascending order.
1129 * Python/Guile scripting
1131 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1132 special section named `.debug_gdb_scripts'.
1134 * New remote packets
1136 qXfer:btrace-conf:read
1137 Return the branch trace configuration for the current thread.
1139 Qbtrace-conf:bts:size
1140 Set the requested ring buffer size for branch tracing in BTS format.
1143 Enable Intel Procesor Trace-based branch tracing for the current
1144 process. The remote stub reports support for this packet to GDB's
1147 Qbtrace-conf:pt:size
1148 Set the requested ring buffer size for branch tracing in Intel Processor
1152 Indicates a memory breakpoint instruction was executed, irrespective
1153 of whether it was GDB that planted the breakpoint or the breakpoint
1154 is hardcoded in the program. This is required for correct non-stop
1158 Indicates the target stopped for a hardware breakpoint. This is
1159 required for correct non-stop mode operation.
1162 Return information about files on the remote system.
1164 qXfer:exec-file:read
1165 Return the full absolute name of the file that was executed to
1166 create a process running on the remote system.
1169 Select the filesystem on which vFile: operations with filename
1170 arguments will operate. This is required for GDB to be able to
1171 access files on remote targets where the remote stub does not
1172 share a common filesystem with the inferior(s).
1175 Indicates that a fork system call was executed.
1178 Indicates that a vfork system call was executed.
1180 vforkdone stop reason
1181 Indicates that a vfork child of the specified process has executed
1182 an exec or exit, allowing the vfork parent to resume execution.
1184 fork-events and vfork-events features in qSupported
1185 The qSupported packet allows GDB to request support for fork and
1186 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1187 and the qSupported response can contain the corresponding
1188 'stubfeatures'. Set and show commands can be used to display
1189 whether these features are enabled.
1191 * Extended-remote fork events
1193 ** GDB now has support for fork events on extended-remote Linux
1194 targets. For targets with Linux kernels 2.5.60 and later, this
1195 enables follow-fork-mode and detach-on-fork for both fork and
1196 vfork, as well as fork and vfork catchpoints.
1198 * The info record command now shows the recording format and the
1199 branch tracing configuration for the current thread when using
1200 the btrace record target.
1201 For the BTS format, it shows the ring buffer size.
1203 * GDB now has support for DTrace USDT (Userland Static Defined
1204 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1206 * GDB now supports access to vector registers on S/390 GNU/Linux
1209 * Removed command line options
1211 -xdb HP-UX XDB compatibility mode.
1213 * Removed targets and native configurations
1215 HP/PA running HP-UX hppa*-*-hpux*
1216 Itanium running HP-UX ia64-*-hpux*
1218 * New configure options
1221 This configure option allows the user to build GDB with support for
1222 Intel Processor Trace (default: auto). This requires libipt.
1224 --with-libipt-prefix=PATH
1225 Specify the path to the version of libipt that GDB should use.
1226 $PATH/include should contain the intel-pt.h header and
1227 $PATH/lib should contain the libipt.so library.
1229 *** Changes in GDB 7.9.1
1233 ** Xmethods can now specify a result type.
1235 *** Changes in GDB 7.9
1237 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1241 ** You can now access frame registers from Python scripts.
1242 ** New attribute 'producer' for gdb.Symtab objects.
1243 ** gdb.Objfile objects have a new attribute "progspace",
1244 which is the gdb.Progspace object of the containing program space.
1245 ** gdb.Objfile objects have a new attribute "owner".
1246 ** gdb.Objfile objects have a new attribute "build_id",
1247 which is the build ID generated when the file was built.
1248 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1249 ** A new event "gdb.clear_objfiles" has been added, triggered when
1250 selecting a new file to debug.
1251 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1252 ** New function gdb.lookup_objfile.
1254 New events which are triggered when GDB modifies the state of the
1257 ** gdb.events.inferior_call_pre: Function call is about to be made.
1258 ** gdb.events.inferior_call_post: Function call has just been made.
1259 ** gdb.events.memory_changed: A memory location has been altered.
1260 ** gdb.events.register_changed: A register has been altered.
1262 * New Python-based convenience functions:
1264 ** $_caller_is(name [, number_of_frames])
1265 ** $_caller_matches(regexp [, number_of_frames])
1266 ** $_any_caller_is(name [, number_of_frames])
1267 ** $_any_caller_matches(regexp [, number_of_frames])
1269 * GDB now supports the compilation and injection of source code into
1270 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1271 to compile the source code to object code, and if successful, inject
1272 and execute that code within the current context of the inferior.
1273 Currently the C language is supported. The commands used to
1274 interface with this new feature are:
1276 compile code [-raw|-r] [--] [source code]
1277 compile file [-raw|-r] filename
1281 demangle [-l language] [--] name
1282 Demangle "name" in the specified language, or the current language
1283 if elided. This command is renamed from the "maint demangle" command.
1284 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1285 as "maint demangler-warning".
1287 queue-signal signal-name-or-number
1288 Queue a signal to be delivered to the thread when it is resumed.
1290 add-auto-load-scripts-directory directory
1291 Add entries to the list of directories from which to load auto-loaded
1294 maint print user-registers
1295 List all currently available "user" registers.
1297 compile code [-r|-raw] [--] [source code]
1298 Compile, inject, and execute in the inferior the executable object
1299 code produced by compiling the provided source code.
1301 compile file [-r|-raw] filename
1302 Compile and inject into the inferior the executable object code
1303 produced by compiling the source code stored in the filename
1306 * On resume, GDB now always passes the signal the program had stopped
1307 for to the thread the signal was sent to, even if the user changed
1308 threads before resuming. Previously GDB would often (but not
1309 always) deliver the signal to the thread that happens to be current
1312 * Conversely, the "signal" command now consistently delivers the
1313 requested signal to the current thread. GDB now asks for
1314 confirmation if the program had stopped for a signal and the user
1315 switched threads meanwhile.
1317 * "breakpoint always-inserted" modes "off" and "auto" merged.
1319 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1320 won't remove breakpoints from the target until all threads stop,
1321 even in non-stop mode. The "auto" mode has been removed, and "off"
1322 is now the default mode.
1326 set debug symbol-lookup
1327 show debug symbol-lookup
1328 Control display of debugging info regarding symbol lookup.
1332 ** The -list-thread-groups command outputs an exit-code field for
1333 inferiors that have exited.
1337 MIPS SDE mips*-sde*-elf*
1341 Support for these obsolete configurations has been removed.
1343 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1344 SGI Irix-5.x mips-*-irix5*
1345 SGI Irix-6.x mips-*-irix6*
1346 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1347 VAX running Ultrix vax-*-ultrix*
1349 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1350 and "assf"), have been removed. Use the "sharedlibrary" command, or
1351 its alias "share", instead.
1353 *** Changes in GDB 7.8
1355 * New command line options
1358 This is an alias for the --data-directory option.
1360 * GDB supports printing and modifying of variable length automatic arrays
1361 as specified in ISO C99.
1363 * The ARM simulator now supports instruction level tracing
1364 with or without disassembly.
1368 GDB now has support for scripting using Guile. Whether this is
1369 available is determined at configure time.
1370 Guile version 2.0 or greater is required.
1371 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1373 * New commands (for set/show, see "New options" below)
1377 Invoke CODE by passing it to the Guile interpreter.
1381 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1383 info auto-load guile-scripts [regexp]
1384 Print the list of automatically loaded Guile scripts.
1386 * The source command is now capable of sourcing Guile scripts.
1387 This feature is dependent on the debugger being built with Guile support.
1391 set print symbol-loading (off|brief|full)
1392 show print symbol-loading
1393 Control whether to print informational messages when loading symbol
1394 information for a file. The default is "full", but when debugging
1395 programs with large numbers of shared libraries the amount of output
1396 becomes less useful.
1398 set guile print-stack (none|message|full)
1399 show guile print-stack
1400 Show a stack trace when an error is encountered in a Guile script.
1402 set auto-load guile-scripts (on|off)
1403 show auto-load guile-scripts
1404 Control auto-loading of Guile script files.
1406 maint ada set ignore-descriptive-types (on|off)
1407 maint ada show ignore-descriptive-types
1408 Control whether the debugger should ignore descriptive types in Ada
1409 programs. The default is not to ignore the descriptive types. See
1410 the user manual for more details on descriptive types and the intended
1411 usage of this option.
1413 set auto-connect-native-target
1415 Control whether GDB is allowed to automatically connect to the
1416 native target for the run, attach, etc. commands when not connected
1417 to any target yet. See also "target native" below.
1419 set record btrace replay-memory-access (read-only|read-write)
1420 show record btrace replay-memory-access
1421 Control what memory accesses are allowed during replay.
1423 maint set target-async (on|off)
1424 maint show target-async
1425 This controls whether GDB targets operate in synchronous or
1426 asynchronous mode. Normally the default is asynchronous, if it is
1427 available; but this can be changed to more easily debug problems
1428 occurring only in synchronous mode.
1430 set mi-async (on|off)
1432 Control whether MI asynchronous mode is preferred. This supersedes
1433 "set target-async" of previous GDB versions.
1435 * "set target-async" is deprecated as a CLI option and is now an alias
1436 for "set mi-async" (only puts MI into async mode).
1438 * Background execution commands (e.g., "c&", "s&", etc.) are now
1439 possible ``out of the box'' if the target supports them. Previously
1440 the user would need to explicitly enable the possibility with the
1441 "set target-async on" command.
1443 * New features in the GDB remote stub, GDBserver
1445 ** New option --debug-format=option1[,option2,...] allows one to add
1446 additional text to each output. At present only timestamps
1447 are supported: --debug-format=timestamps.
1448 Timestamps can also be turned on with the
1449 "monitor set debug-format timestamps" command from GDB.
1451 * The 'record instruction-history' command now starts counting instructions
1452 at one. This also affects the instruction ranges reported by the
1453 'record function-call-history' command when given the /i modifier.
1455 * The command 'record function-call-history' supports a new modifier '/c' to
1456 indent the function names based on their call stack depth.
1457 The fields for the '/i' and '/l' modifier have been reordered.
1458 The source line range is now prefixed with 'at'.
1459 The instruction range is now prefixed with 'inst'.
1460 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1461 "record instruction-history" and "list" commands.
1463 * The ranges given as arguments to the 'record function-call-history' and
1464 'record instruction-history' commands are now inclusive.
1466 * The btrace record target now supports the 'record goto' command.
1467 For locations inside the execution trace, the back trace is computed
1468 based on the information stored in the execution trace.
1470 * The btrace record target supports limited reverse execution and replay.
1471 The target does not record data and therefore does not allow reading
1472 memory or registers.
1474 * The "catch syscall" command now works on s390*-linux* targets.
1476 * The "compare-sections" command is no longer specific to target
1477 remote. It now works with all targets.
1479 * All native targets are now consistently called "native".
1480 Consequently, the "target child", "target GNU", "target djgpp",
1481 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1482 commands have been replaced with "target native". The QNX/NTO port
1483 leaves the "procfs" target in place and adds a "native" target for
1484 consistency with other ports. The impact on users should be minimal
1485 as these commands previously either throwed an error, or were
1486 no-ops. The target's name is visible in the output of the following
1487 commands: "help target", "info target", "info files", "maint print
1490 * The "target native" command now connects to the native target. This
1491 can be used to launch native programs even when "set
1492 auto-connect-native-target" is set to off.
1494 * GDB now supports access to Intel MPX registers on GNU/Linux.
1496 * Support for Intel AVX-512 registers on GNU/Linux.
1497 Support displaying and modifying Intel AVX-512 registers
1498 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1500 * New remote packets
1502 qXfer:btrace:read's annex
1503 The qXfer:btrace:read packet supports a new annex 'delta' to read
1504 branch trace incrementally.
1508 ** Valid Python operations on gdb.Value objects representing
1509 structs/classes invoke the corresponding overloaded operators if
1511 ** New `Xmethods' feature in the Python API. Xmethods are
1512 additional methods or replacements for existing methods of a C++
1513 class. This feature is useful for those cases where a method
1514 defined in C++ source code could be inlined or optimized out by
1515 the compiler, making it unavailable to GDB.
1518 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1520 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1521 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1522 its alias "share", instead.
1524 * The commands "set remotebaud" and "show remotebaud" are no longer
1525 supported. Use "set serial baud" and "show serial baud" (respectively)
1530 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1531 target-async". The latter is left as a deprecated alias of the
1532 former for backward compatibility. If the target supports it,
1533 CLI background execution commands are now always possible by
1534 default, independently of whether the frontend stated a
1535 preference for asynchronous execution with "-gdb-set mi-async".
1536 Previously "-gdb-set target-async off" affected both MI execution
1537 commands and CLI execution commands.
1539 *** Changes in GDB 7.7
1541 * Improved support for process record-replay and reverse debugging on
1542 arm*-linux* targets. Support for thumb32 and syscall instruction
1543 recording has been added.
1545 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1547 * GDB now supports Fission DWP file format version 2.
1548 http://gcc.gnu.org/wiki/DebugFission
1550 * New convenience function "$_isvoid", to check whether an expression
1551 is void. A void expression is an expression where the type of the
1552 result is "void". For example, some convenience variables may be
1553 "void" when evaluated (e.g., "$_exitcode" before the execution of
1554 the program being debugged; or an undefined convenience variable).
1555 Another example, when calling a function whose return type is
1558 * The "maintenance print objfiles" command now takes an optional regexp.
1560 * The "catch syscall" command now works on arm*-linux* targets.
1562 * GDB now consistently shows "<not saved>" when printing values of
1563 registers the debug info indicates have not been saved in the frame
1564 and there's nowhere to retrieve them from
1565 (callee-saved/call-clobbered registers):
1570 (gdb) info registers rax
1573 Before, the former would print "<optimized out>", and the latter
1574 "*value not available*".
1576 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1581 ** Frame filters and frame decorators have been added.
1582 ** Temporary breakpoints are now supported.
1583 ** Line tables representation has been added.
1584 ** New attribute 'parent_type' for gdb.Field objects.
1585 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1586 ** New attribute 'name' for gdb.Type objects.
1590 Nios II ELF nios2*-*-elf
1591 Nios II GNU/Linux nios2*-*-linux
1592 Texas Instruments MSP430 msp430*-*-elf
1594 * Removed native configurations
1596 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1597 been removed. ELF variants of these configurations are kept supported.
1599 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1600 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1601 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1602 i[34567]86-*-openbsd3.[0-3]
1603 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1604 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1605 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1609 Like "catch throw", but catches a re-thrown exception.
1610 maint check-psymtabs
1611 Renamed from old "maint check-symtabs".
1613 Perform consistency checks on symtabs.
1614 maint expand-symtabs
1615 Expand symtabs matching an optional regexp.
1618 Display the details of GDB configure-time options.
1620 maint set|show per-command
1621 maint set|show per-command space
1622 maint set|show per-command time
1623 maint set|show per-command symtab
1624 Enable display of per-command gdb resource usage.
1626 remove-symbol-file FILENAME
1627 remove-symbol-file -a ADDRESS
1628 Remove a symbol file added via add-symbol-file. The file to remove
1629 can be identified by its filename or by an address that lies within
1630 the boundaries of this symbol file in memory.
1633 info exceptions REGEXP
1634 Display the list of Ada exceptions defined in the program being
1635 debugged. If provided, only the exceptions whose names match REGEXP
1640 set debug symfile off|on
1642 Control display of debugging info regarding reading symbol files and
1643 symbol tables within those files
1645 set print raw frame-arguments
1646 show print raw frame-arguments
1647 Set/show whether to print frame arguments in raw mode,
1648 disregarding any defined pretty-printers.
1650 set remote trace-status-packet
1651 show remote trace-status-packet
1652 Set/show the use of remote protocol qTStatus packet.
1656 Control display of debugging messages related to Nios II targets.
1660 Control whether target-assisted range stepping is enabled.
1662 set startup-with-shell
1663 show startup-with-shell
1664 Specifies whether Unix child processes are started via a shell or
1669 Use the target memory cache for accesses to the code segment. This
1670 improves performance of remote debugging (particularly disassembly).
1672 * You can now use a literal value 'unlimited' for options that
1673 interpret 0 or -1 as meaning "unlimited". E.g., "set
1674 trace-buffer-size unlimited" is now an alias for "set
1675 trace-buffer-size -1" and "set height unlimited" is now an alias for
1678 * The "set debug symtab-create" debugging option of GDB has been changed to
1679 accept a verbosity level. 0 means "off", 1 provides basic debugging
1680 output, and values of 2 or greater provides more verbose output.
1682 * New command-line options
1684 Display the details of GDB configure-time options.
1686 * The command 'tsave' can now support new option '-ctf' to save trace
1687 buffer in Common Trace Format.
1689 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1692 * GDB now implements the the C++ 'typeid' operator.
1694 * The new convenience variable $_exception holds the exception being
1695 thrown or caught at an exception-related catchpoint.
1697 * The exception-related catchpoints, like "catch throw", now accept a
1698 regular expression which can be used to filter exceptions by type.
1700 * The new convenience variable $_exitsignal is automatically set to
1701 the terminating signal number when the program being debugged dies
1702 due to an uncaught signal.
1706 ** All MI commands now accept an optional "--language" option.
1707 Support for this feature can be verified by using the "-list-features"
1708 command, which should contain "language-option".
1710 ** The new command -info-gdb-mi-command allows the user to determine
1711 whether a GDB/MI command is supported or not.
1713 ** The "^error" result record returned when trying to execute an undefined
1714 GDB/MI command now provides a variable named "code" whose content is the
1715 "undefined-command" error code. Support for this feature can be verified
1716 by using the "-list-features" command, which should contain
1717 "undefined-command-error-code".
1719 ** The -trace-save MI command can optionally save trace buffer in Common
1722 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1724 ** The command -data-list-register-values now accepts an optional
1725 "--skip-unavailable" option. When used, only the available registers
1728 ** The new command -trace-frame-collected dumps collected variables,
1729 computed expressions, tvars, memory and registers in a traceframe.
1731 ** The commands -stack-list-locals, -stack-list-arguments and
1732 -stack-list-variables now accept an option "--skip-unavailable".
1733 When used, only the available locals or arguments are displayed.
1735 ** The -exec-run command now accepts an optional "--start" option.
1736 When used, the command follows the same semantics as the "start"
1737 command, stopping the program's execution at the start of its
1738 main subprogram. Support for this feature can be verified using
1739 the "-list-features" command, which should contain
1740 "exec-run-start-option".
1742 ** The new commands -catch-assert and -catch-exceptions insert
1743 catchpoints stopping the program when Ada exceptions are raised.
1745 ** The new command -info-ada-exceptions provides the equivalent of
1746 the new "info exceptions" command.
1748 * New system-wide configuration scripts
1749 A GDB installation now provides scripts suitable for use as system-wide
1750 configuration scripts for the following systems:
1754 * GDB now supports target-assigned range stepping with remote targets.
1755 This improves the performance of stepping source lines by reducing
1756 the number of control packets from/to GDB. See "New remote packets"
1759 * GDB now understands the element 'tvar' in the XML traceframe info.
1760 It has the id of the collected trace state variables.
1762 * On S/390 targets that provide the transactional-execution feature,
1763 the program interruption transaction diagnostic block (TDB) is now
1764 represented as a number of additional "registers" in GDB.
1766 * New remote packets
1770 The vCont packet supports a new 'r' action, that tells the remote
1771 stub to step through an address range itself, without GDB
1772 involvemement at each single-step.
1774 qXfer:libraries-svr4:read's annex
1775 The previously unused annex of the qXfer:libraries-svr4:read packet
1776 is now used to support passing an argument list. The remote stub
1777 reports support for this argument list to GDB's qSupported query.
1778 The defined arguments are "start" and "prev", used to reduce work
1779 necessary for library list updating, resulting in significant
1782 * New features in the GDB remote stub, GDBserver
1784 ** GDBserver now supports target-assisted range stepping. Currently
1785 enabled on x86/x86_64 GNU/Linux targets.
1787 ** GDBserver now adds element 'tvar' in the XML in the reply to
1788 'qXfer:traceframe-info:read'. It has the id of the collected
1789 trace state variables.
1791 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1794 * New 'z' formatter for printing and examining memory, this displays the
1795 value as hexadecimal zero padded on the left to the size of the type.
1797 * GDB can now use Windows x64 unwinding data.
1799 * The "set remotebaud" command has been replaced by "set serial baud".
1800 Similarly, "show remotebaud" has been replaced by "show serial baud".
1801 The "set remotebaud" and "show remotebaud" commands are still available
1802 to provide backward compatibility with older versions of GDB.
1804 *** Changes in GDB 7.6
1806 * Target record has been renamed to record-full.
1807 Record/replay is now enabled with the "record full" command.
1808 This also affects settings that are associated with full record/replay
1809 that have been moved from "set/show record" to "set/show record full":
1811 set|show record full insn-number-max
1812 set|show record full stop-at-limit
1813 set|show record full memory-query
1815 * A new record target "record-btrace" has been added. The new target
1816 uses hardware support to record the control-flow of a process. It
1817 does not support replaying the execution, but it implements the
1818 below new commands for investigating the recorded execution log.
1819 This new recording method can be enabled using:
1823 The "record-btrace" target is only available on Intel Atom processors
1824 and requires a Linux kernel 2.6.32 or later.
1826 * Two new commands have been added for record/replay to give information
1827 about the recorded execution without having to replay the execution.
1828 The commands are only supported by "record btrace".
1830 record instruction-history prints the execution history at
1831 instruction granularity
1833 record function-call-history prints the execution history at
1834 function granularity
1836 * New native configurations
1838 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1839 FreeBSD/powerpc powerpc*-*-freebsd
1840 x86_64/Cygwin x86_64-*-cygwin*
1841 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1845 ARM AArch64 aarch64*-*-elf
1846 ARM AArch64 GNU/Linux aarch64*-*-linux
1847 Lynx 178 PowerPC powerpc-*-lynx*178
1848 x86_64/Cygwin x86_64-*-cygwin*
1849 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1851 * If the configured location of system.gdbinit file (as given by the
1852 --with-system-gdbinit option at configure time) is in the
1853 data-directory (as specified by --with-gdb-datadir at configure
1854 time) or in one of its subdirectories, then GDB will look for the
1855 system-wide init file in the directory specified by the
1856 --data-directory command-line option.
1858 * New command line options:
1860 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1861 other initialization files, unlike -nx which disables all of them.
1863 * Removed command line options
1865 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1868 * The 'ptype' and 'whatis' commands now accept an argument to control
1871 * 'info proc' now works on some core files.
1875 ** Vectors can be created with gdb.Type.vector.
1877 ** Python's atexit.register now works in GDB.
1879 ** Types can be pretty-printed via a Python API.
1881 ** Python 3 is now supported (in addition to Python 2.4 or later)
1883 ** New class gdb.Architecture exposes GDB's internal representation
1884 of architecture in the Python API.
1886 ** New method Frame.architecture returns the gdb.Architecture object
1887 corresponding to the frame's architecture.
1889 * New Python-based convenience functions:
1891 ** $_memeq(buf1, buf2, length)
1892 ** $_streq(str1, str2)
1894 ** $_regex(str, regex)
1896 * The 'cd' command now defaults to using '~' (the home directory) if not
1899 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1900 default for GCC since November 2000.
1902 * The command 'forward-search' can now be abbreviated as 'fo'.
1904 * The command 'info tracepoints' can now display 'installed on target'
1905 or 'not installed on target' for each non-pending location of tracepoint.
1907 * New configure options
1909 --enable-libmcheck/--disable-libmcheck
1910 By default, development versions are built with -lmcheck on hosts
1911 that support it, in order to help track memory corruption issues.
1912 Release versions, on the other hand, are built without -lmcheck
1913 by default. The --enable-libmcheck/--disable-libmcheck configure
1914 options allow the user to override that default.
1915 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1916 This configure option allows the user to build GDB with
1917 libbabeltrace using which GDB can read Common Trace Format data.
1919 * New commands (for set/show, see "New options" below)
1922 Catch signals. This is similar to "handle", but allows commands and
1923 conditions to be attached.
1926 List the BFDs known to GDB.
1928 python-interactive [command]
1930 Start a Python interactive prompt, or evaluate the optional command
1931 and print the result of expressions.
1934 "py" is a new alias for "python".
1936 enable type-printer [name]...
1937 disable type-printer [name]...
1938 Enable or disable type printers.
1942 ** For the Renesas Super-H architecture, the "regs" command has been removed
1943 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1948 set print type methods (on|off)
1949 show print type methods
1950 Control whether method declarations are displayed by "ptype".
1951 The default is to show them.
1953 set print type typedefs (on|off)
1954 show print type typedefs
1955 Control whether typedef definitions are displayed by "ptype".
1956 The default is to show them.
1958 set filename-display basename|relative|absolute
1959 show filename-display
1960 Control the way in which filenames is displayed.
1961 The default is "relative", which preserves previous behavior.
1963 set trace-buffer-size
1964 show trace-buffer-size
1965 Request target to change the size of trace buffer.
1967 set remote trace-buffer-size-packet auto|on|off
1968 show remote trace-buffer-size-packet
1969 Control the use of the remote protocol `QTBuffer:size' packet.
1973 Control display of debugging messages related to ARM AArch64.
1976 set debug coff-pe-read
1977 show debug coff-pe-read
1978 Control display of debugging messages related to reading of COFF/PE
1983 Control display of debugging messages related to Mach-O symbols
1986 set debug notification
1987 show debug notification
1988 Control display of debugging info for async remote notification.
1992 ** Command parameter changes are now notified using new async record
1993 "=cmd-param-changed".
1994 ** Trace frame changes caused by command "tfind" are now notified using
1995 new async record "=traceframe-changed".
1996 ** The creation, deletion and modification of trace state variables
1997 are now notified using new async records "=tsv-created",
1998 "=tsv-deleted" and "=tsv-modified".
1999 ** The start and stop of process record are now notified using new
2000 async record "=record-started" and "=record-stopped".
2001 ** Memory changes are now notified using new async record
2003 ** The data-disassemble command response will include a "fullname" field
2004 containing the absolute file name when source has been requested.
2005 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2006 command, to allow pattern filling of memory areas.
2007 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2008 library load/unload events.
2009 ** The response to breakpoint commands and breakpoint async records
2010 includes an "installed" field containing a boolean state about each
2011 non-pending tracepoint location is whether installed on target or not.
2012 ** Output of the "-trace-status" command includes a "trace-file" field
2013 containing the name of the trace file being examined. This field is
2014 optional, and only present when examining a trace file.
2015 ** The "fullname" field is now always present along with the "file" field,
2016 even if the file cannot be found by GDB.
2018 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2019 You must have the LZMA library available when configuring GDB for this
2020 feature to be enabled. For more information, see:
2021 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2023 * New remote packets
2026 Set the size of trace buffer. The remote stub reports support for this
2027 packet to gdb's qSupported query.
2030 Enable Branch Trace Store (BTS)-based branch tracing for the current
2031 thread. The remote stub reports support for this packet to gdb's
2035 Disable branch tracing for the current thread. The remote stub reports
2036 support for this packet to gdb's qSupported query.
2039 Read the traced branches for the current thread. The remote stub
2040 reports support for this packet to gdb's qSupported query.
2042 *** Changes in GDB 7.5
2044 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2045 for more x32 ABI info.
2047 * GDB now supports access to MIPS DSP registers on Linux targets.
2049 * GDB now supports debugging microMIPS binaries.
2051 * The "info os" command on GNU/Linux can now display information on
2052 several new classes of objects managed by the operating system:
2053 "info os procgroups" lists process groups
2054 "info os files" lists file descriptors
2055 "info os sockets" lists internet-domain sockets
2056 "info os shm" lists shared-memory regions
2057 "info os semaphores" lists semaphores
2058 "info os msg" lists message queues
2059 "info os modules" lists loaded kernel modules
2061 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2062 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2063 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2064 options and inspect the probe arguments using the new $_probe_arg family
2065 of convenience variables. You can obtain more information about SystemTap
2066 in <http://sourceware.org/systemtap/>.
2068 * GDB now supports reversible debugging on ARM, it allows you to
2069 debug basic ARM and THUMB instructions, and provides
2070 record/replay support.
2072 * The option "symbol-reloading" has been deleted as it is no longer used.
2076 ** GDB commands implemented in Python can now be put in command class
2079 ** The "maint set python print-stack on|off" is now deleted.
2081 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2082 apply "flag enum"-style pretty-printing to any enum.
2084 ** gdb.lookup_symbol can now work when there is no current frame.
2086 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2087 the source at which the symbol was defined.
2089 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2090 method 'value'. The former indicates whether the symbol needs a
2091 frame in order to compute its value, and the latter computes the
2094 ** A new method 'referenced_value' on gdb.Value objects which can
2095 dereference pointer as well as C++ reference values.
2097 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2098 which return the global and static blocks (as gdb.Block objects),
2099 of the underlying symbol table, respectively.
2101 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2102 object associated with a PC value.
2104 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2105 of the address range occupied by code for the current source line.
2107 * Go language support.
2108 GDB now supports debugging programs written in the Go programming
2111 * GDBserver now supports stdio connections.
2112 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2114 * The binary "gdbtui" can no longer be built or installed.
2115 Use "gdb -tui" instead.
2117 * GDB will now print "flag" enums specially. A flag enum is one where
2118 all the enumerator values have no bits in common when pairwise
2119 "and"ed. When printing a value whose type is a flag enum, GDB will
2120 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2121 (gdb) print (enum E) 3
2124 * The filename part of a linespec will now match trailing components
2125 of a source file name. For example, "break gcc/expr.c:1000" will
2126 now set a breakpoint in build/gcc/expr.c, but not
2127 build/libcpp/expr.c.
2129 * The "info proc" and "generate-core-file" commands will now also
2130 work on remote targets connected to GDBserver on Linux.
2132 * The command "info catch" has been removed. It has been disabled
2133 since December 2007.
2135 * The "catch exception" and "catch assert" commands now accept
2136 a condition at the end of the command, much like the "break"
2137 command does. For instance:
2139 (gdb) catch exception Constraint_Error if Barrier = True
2141 Previously, it was possible to add a condition to such catchpoints,
2142 but it had to be done as a second step, after the catchpoint had been
2143 created, using the "condition" command.
2145 * The "info static-tracepoint-marker" command will now also work on
2146 native Linux targets with in-process agent.
2148 * GDB can now set breakpoints on inlined functions.
2150 * The .gdb_index section has been updated to include symbols for
2151 inlined functions. GDB will ignore older .gdb_index sections by
2152 default, which could cause symbol files to be loaded more slowly
2153 until their .gdb_index sections can be recreated. The new command
2154 "set use-deprecated-index-sections on" will cause GDB to use any older
2155 .gdb_index sections it finds. This will restore performance, but the
2156 ability to set breakpoints on inlined functions will be lost in symbol
2157 files with older .gdb_index sections.
2159 The .gdb_index section has also been updated to record more information
2160 about each symbol. This speeds up the "info variables", "info functions"
2161 and "info types" commands when used with programs having the .gdb_index
2162 section, as well as speeding up debugging with shared libraries using
2163 the .gdb_index section.
2165 * Ada support for GDB/MI Variable Objects has been added.
2167 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2172 ** New command -info-os is the MI equivalent of "info os".
2174 ** Output logs ("set logging" and related) now include MI output.
2178 ** "set use-deprecated-index-sections on|off"
2179 "show use-deprecated-index-sections on|off"
2180 Controls the use of deprecated .gdb_index sections.
2182 ** "catch load" and "catch unload" can be used to stop when a shared
2183 library is loaded or unloaded, respectively.
2185 ** "enable count" can be used to auto-disable a breakpoint after
2188 ** "info vtbl" can be used to show the virtual method tables for
2189 C++ and Java objects.
2191 ** "explore" and its sub commands "explore value" and "explore type"
2192 can be used to recursively explore values and types of
2193 expressions. These commands are available only if GDB is
2194 configured with '--with-python'.
2196 ** "info auto-load" shows status of all kinds of auto-loaded files,
2197 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2198 sequences of commands files, "info auto-load python-scripts"
2199 shows status of auto-loading Python script files,
2200 "info auto-load local-gdbinit" shows status of loading init file
2201 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2202 status of inferior specific thread debugging shared library loading.
2204 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2205 and "show auto-load-scripts" commands have been deprecated, use their
2206 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2207 and "show auto-load python-scripts" counterparts instead.
2209 ** "dprintf location,format,args..." creates a dynamic printf, which
2210 is basically a breakpoint that does a printf and immediately
2211 resumes your program's execution, so it is like a printf that you
2212 can insert dynamically at runtime instead of at compiletime.
2214 ** "set print symbol"
2216 Controls whether GDB attempts to display the symbol, if any,
2217 corresponding to addresses it prints. This defaults to "on", but
2218 you can set it to "off" to restore GDB's previous behavior.
2220 * Deprecated commands
2222 ** For the Renesas Super-H architecture, the "regs" command has been
2223 deprecated, and "info all-registers" should be used instead.
2227 Renesas RL78 rl78-*-elf
2228 HP OpenVMS ia64 ia64-hp-openvms*
2230 * GDBserver supports evaluation of breakpoint conditions. When
2231 support is advertised by GDBserver, GDB may be told to send the
2232 breakpoint conditions in bytecode form to GDBserver. GDBserver
2233 will only report the breakpoint trigger to GDB when its condition
2238 set mips compression
2239 show mips compression
2240 Select the compressed ISA encoding used in functions that have no symbol
2241 information available. The encoding can be set to either of:
2244 and is updated automatically from ELF file flags if available.
2246 set breakpoint condition-evaluation
2247 show breakpoint condition-evaluation
2248 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2249 GDBserver ("target"). Default option "auto" chooses the most efficient
2251 This option can improve debugger efficiency depending on the speed of the
2255 Disable auto-loading globally.
2258 Show auto-loading setting of all kinds of auto-loaded files.
2260 set auto-load gdb-scripts on|off
2261 show auto-load gdb-scripts
2262 Control auto-loading of GDB canned sequences of commands files.
2264 set auto-load python-scripts on|off
2265 show auto-load python-scripts
2266 Control auto-loading of Python script files.
2268 set auto-load local-gdbinit on|off
2269 show auto-load local-gdbinit
2270 Control loading of init file (.gdbinit) from current directory.
2272 set auto-load libthread-db on|off
2273 show auto-load libthread-db
2274 Control auto-loading of inferior specific thread debugging shared library.
2276 set auto-load scripts-directory <dir1>[:<dir2>...]
2277 show auto-load scripts-directory
2278 Set a list of directories from which to load auto-loaded scripts.
2279 Automatically loaded Python scripts and GDB scripts are located in one
2280 of the directories listed by this option.
2281 The delimiter (':' above) may differ according to the host platform.
2283 set auto-load safe-path <dir1>[:<dir2>...]
2284 show auto-load safe-path
2285 Set a list of directories from which it is safe to auto-load files.
2286 The delimiter (':' above) may differ according to the host platform.
2288 set debug auto-load on|off
2289 show debug auto-load
2290 Control display of debugging info for auto-loading the files above.
2292 set dprintf-style gdb|call|agent
2294 Control the way in which a dynamic printf is performed; "gdb"
2295 requests a GDB printf command, while "call" causes dprintf to call a
2296 function in the inferior. "agent" requests that the target agent
2297 (such as GDBserver) do the printing.
2299 set dprintf-function <expr>
2300 show dprintf-function
2301 set dprintf-channel <expr>
2302 show dprintf-channel
2303 Set the function and optional first argument to the call when using
2304 the "call" style of dynamic printf.
2306 set disconnected-dprintf on|off
2307 show disconnected-dprintf
2308 Control whether agent-style dynamic printfs continue to be in effect
2309 after GDB disconnects.
2311 * New configure options
2313 --with-auto-load-dir
2314 Configure default value for the 'set auto-load scripts-directory'
2315 setting above. It defaults to '$debugdir:$datadir/auto-load',
2316 $debugdir representing global debugging info directories (available
2317 via 'show debug-file-directory') and $datadir representing GDB's data
2318 directory (available via 'show data-directory').
2320 --with-auto-load-safe-path
2321 Configure default value for the 'set auto-load safe-path' setting
2322 above. It defaults to the --with-auto-load-dir setting.
2324 --without-auto-load-safe-path
2325 Set 'set auto-load safe-path' to '/', effectively disabling this
2328 * New remote packets
2330 z0/z1 conditional breakpoints extension
2332 The z0/z1 breakpoint insertion packets have been extended to carry
2333 a list of conditional expressions over to the remote stub depending on the
2334 condition evaluation mode. The use of this extension can be controlled
2335 via the "set remote conditional-breakpoints-packet" command.
2339 Specify the signals which the remote stub may pass to the debugged
2340 program without GDB involvement.
2342 * New command line options
2344 --init-command=FILE, -ix Like --command, -x but execute it
2345 before loading inferior.
2346 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2347 execute it before loading inferior.
2349 *** Changes in GDB 7.4
2351 * GDB now handles ambiguous linespecs more consistently; the existing
2352 FILE:LINE support has been expanded to other types of linespecs. A
2353 breakpoint will now be set on all matching locations in all
2354 inferiors, and locations will be added or removed according to
2357 * GDB now allows you to skip uninteresting functions and files when
2358 stepping with the "skip function" and "skip file" commands.
2360 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2361 and "show remote hardware-watchpoint-length-limit". These allows to
2362 set or show the maximum length limit (in bytes) of a remote
2363 target hardware watchpoint.
2365 This allows e.g. to use "unlimited" hardware watchpoints with the
2366 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2367 watchpoints are slower than real hardware watchpoints but are
2368 significantly faster than gdb software watchpoints.
2372 ** The register_pretty_printer function in module gdb.printing now takes
2373 an optional `replace' argument. If True, the new printer replaces any
2376 ** The "maint set python print-stack on|off" command has been
2377 deprecated and will be deleted in GDB 7.5.
2378 A new command: "set python print-stack none|full|message" has
2379 replaced it. Additionally, the default for "print-stack" is
2380 now "message", which just prints the error message without
2383 ** A prompt substitution hook (prompt_hook) is now available to the
2386 ** A new Python module, gdb.prompt has been added to the GDB Python
2387 modules library. This module provides functionality for
2388 escape sequences in prompts (used by set/show
2389 extended-prompt). These escape sequences are replaced by their
2390 corresponding value.
2392 ** Python commands and convenience-functions located in
2393 'data-directory'/python/gdb/command and
2394 'data-directory'/python/gdb/function are now automatically loaded
2397 ** Blocks now provide four new attributes. global_block and
2398 static_block will return the global and static blocks
2399 respectively. is_static and is_global are boolean attributes
2400 that indicate if the block is one of those two types.
2402 ** Symbols now provide the "type" attribute, the type of the symbol.
2404 ** The "gdb.breakpoint" function has been deprecated in favor of
2407 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2408 of a function. This class is based on the "finish" command
2409 available in the CLI.
2411 ** Type objects for struct and union types now allow access to
2412 the fields using standard Python dictionary (mapping) methods.
2413 For example, "some_type['myfield']" now works, as does
2414 "some_type.items()".
2416 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2419 ** A new function, "deep_items" has been added to the gdb.types
2420 module in the GDB Python modules library. This function returns
2421 an iterator over the fields of a struct or union type. Unlike
2422 the standard Python "iteritems" method, it will recursively traverse
2423 any anonymous fields.
2427 ** "*stopped" events can report several new "reason"s, such as
2430 ** Breakpoint changes are now notified using new async records, like
2431 "=breakpoint-modified".
2433 ** New command -ada-task-info.
2435 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2436 $sdir specifies the default system locations of shared libraries.
2437 $pdir specifies the directory where the libpthread used by the application
2440 GDB no longer looks in $sdir and $pdir after it has searched the directories
2441 mentioned in libthread-db-search-path. If you want to search those
2442 directories, they must be specified in libthread-db-search-path.
2443 The default value of libthread-db-search-path on GNU/Linux and Solaris
2444 systems is now "$sdir:$pdir".
2446 $pdir is not supported by gdbserver, it is currently ignored.
2447 $sdir is supported by gdbserver.
2449 * New configure option --with-iconv-bin.
2450 When using the internationalization support like the one in the GNU C
2451 library, GDB will invoke the "iconv" program to get a list of supported
2452 character sets. If this program lives in a non-standard location, one can
2453 use this option to specify where to find it.
2455 * When natively debugging programs on PowerPC BookE processors running
2456 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2457 watchpoints, which specify a mask in addition to an address to watch.
2458 The mask specifies that some bits of an address (the bits which are
2459 reset in the mask) should be ignored when matching the address accessed
2460 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2461 section in the user manual for more details.
2463 * The new option --once causes GDBserver to stop listening for connections once
2464 the first connection is made. The listening port used by GDBserver will
2465 become available after that.
2467 * New commands "info macros" and "alias" have been added.
2469 * New function parameters suffix @entry specifies value of function parameter
2470 at the time the function got called. Entry values are available only since
2476 "!" is now an alias of the "shell" command.
2477 Note that no space is needed between "!" and SHELL COMMAND.
2481 watch EXPRESSION mask MASK_VALUE
2482 The watch command now supports the mask argument which allows creation
2483 of masked watchpoints, if the current architecture supports this feature.
2485 info auto-load-scripts [REGEXP]
2486 This command was formerly named "maintenance print section-scripts".
2487 It is now generally useful and is no longer a maintenance-only command.
2489 info macro [-all] [--] MACRO
2490 The info macro command has new options `-all' and `--'. The first for
2491 printing all definitions of a macro. The second for explicitly specifying
2492 the end of arguments and the beginning of the macro name in case the macro
2493 name starts with a hyphen.
2495 collect[/s] EXPRESSIONS
2496 The tracepoint collect command now takes an optional modifier "/s"
2497 that directs it to dereference pointer-to-character types and
2498 collect the bytes of memory up to a zero byte. The behavior is
2499 similar to what you see when you use the regular print command on a
2500 string. An optional integer following the "/s" sets a bound on the
2501 number of bytes that will be collected.
2504 The trace start command now interprets any supplied arguments as a
2505 note to be recorded with the trace run, with an effect similar to
2506 setting the variable trace-notes.
2509 The trace stop command now interprets any arguments as a note to be
2510 mentioned along with the tstatus report that the trace was stopped
2511 with a command. The effect is similar to setting the variable
2514 * Tracepoints can now be enabled and disabled at any time after a trace
2515 experiment has been started using the standard "enable" and "disable"
2516 commands. It is now possible to start a trace experiment with no enabled
2517 tracepoints; GDB will display a warning, but will allow the experiment to
2518 begin, assuming that tracepoints will be enabled as needed while the trace
2521 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2522 locations with 4-byte instructions, when they were previously
2523 limited to locations with instructions of 5 bytes or longer.
2527 set debug dwarf2-read
2528 show debug dwarf2-read
2529 Turns on or off display of debugging messages related to reading
2530 DWARF debug info. The default is off.
2532 set debug symtab-create
2533 show debug symtab-create
2534 Turns on or off display of debugging messages related to symbol table
2535 creation. The default is off.
2538 show extended-prompt
2539 Set the GDB prompt, and allow escape sequences to be inserted to
2540 display miscellaneous information (see 'help set extended-prompt'
2541 for the list of sequences). This prompt (and any information
2542 accessed through the escape sequences) is updated every time the
2543 prompt is displayed.
2545 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2546 show print entry-values
2547 Set printing of frame argument values at function entry. In some cases
2548 GDB can determine the value of function argument which was passed by the
2549 function caller, even if the value was modified inside the called function.
2551 set debug entry-values
2552 show debug entry-values
2553 Control display of debugging info for determining frame argument values at
2554 function entry and virtual tail call frames.
2556 set basenames-may-differ
2557 show basenames-may-differ
2558 Set whether a source file may have multiple base names.
2559 (A "base name" is the name of a file with the directory part removed.
2560 Example: The base name of "/home/user/hello.c" is "hello.c".)
2561 If set, GDB will canonicalize file names (e.g., expand symlinks)
2562 before comparing them. Canonicalization is an expensive operation,
2563 but it allows the same file be known by more than one base name.
2564 If not set (the default), all source files are assumed to have just
2565 one base name, and gdb will do file name comparisons more efficiently.
2571 Set a user name and notes for the current and any future trace runs.
2572 This is useful for long-running and/or disconnected traces, to
2573 inform others (or yourself) as to who is running the trace, supply
2574 contact information, or otherwise explain what is going on.
2576 set trace-stop-notes
2577 show trace-stop-notes
2578 Set a note attached to the trace run, that is displayed when the
2579 trace has been stopped by a tstop command. This is useful for
2580 instance as an explanation, if you are stopping a trace run that was
2581 started by someone else.
2583 * New remote packets
2587 Dynamically enable a tracepoint in a started trace experiment.
2591 Dynamically disable a tracepoint in a started trace experiment.
2595 Set the user and notes of the trace run.
2599 Query the current status of a tracepoint.
2603 Query the minimum length of instruction at which a fast tracepoint may
2606 * Dcache size (number of lines) and line-size are now runtime-configurable
2607 via "set dcache line" and "set dcache line-size" commands.
2611 Texas Instruments TMS320C6x tic6x-*-*
2615 Renesas RL78 rl78-*-elf
2617 *** Changes in GDB 7.3.1
2619 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2621 *** Changes in GDB 7.3
2623 * GDB has a new command: "thread find [REGEXP]".
2624 It finds the thread id whose name, target id, or thread extra info
2625 matches the given regular expression.
2627 * The "catch syscall" command now works on mips*-linux* targets.
2629 * The -data-disassemble MI command now supports modes 2 and 3 for
2630 dumping the instruction opcodes.
2632 * New command line options
2634 -data-directory DIR Specify DIR as the "data-directory".
2635 This is mostly for testing purposes.
2637 * The "maint set python auto-load on|off" command has been renamed to
2638 "set auto-load-scripts on|off".
2640 * GDB has a new command: "set directories".
2641 It is like the "dir" command except that it replaces the
2642 source path list instead of augmenting it.
2644 * GDB now understands thread names.
2646 On GNU/Linux, "info threads" will display the thread name as set by
2647 prctl or pthread_setname_np.
2649 There is also a new command, "thread name", which can be used to
2650 assign a name internally for GDB to display.
2653 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2654 has been integrated into GDB.
2658 ** The function gdb.Write now accepts an optional keyword 'stream'.
2659 This keyword, when provided, will direct the output to either
2660 stdout, stderr, or GDB's logging output.
2662 ** Parameters can now be be sub-classed in Python, and in particular
2663 you may implement the get_set_doc and get_show_doc functions.
2664 This improves how Parameter set/show documentation is processed
2665 and allows for more dynamic content.
2667 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2668 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2669 have an is_valid method.
2671 ** Breakpoints can now be sub-classed in Python, and in particular
2672 you may implement a 'stop' function that is executed each time
2673 the inferior reaches that breakpoint.
2675 ** New function gdb.lookup_global_symbol looks up a global symbol.
2677 ** GDB values in Python are now callable if the value represents a
2678 function. For example, if 'some_value' represents a function that
2679 takes two integer parameters and returns a value, you can call
2680 that function like so:
2682 result = some_value (10,20)
2684 ** Module gdb.types has been added.
2685 It contains a collection of utilities for working with gdb.Types objects:
2686 get_basic_type, has_field, make_enum_dict.
2688 ** Module gdb.printing has been added.
2689 It contains utilities for writing and registering pretty-printers.
2690 New classes: PrettyPrinter, SubPrettyPrinter,
2691 RegexpCollectionPrettyPrinter.
2692 New function: register_pretty_printer.
2694 ** New commands "info pretty-printers", "enable pretty-printer" and
2695 "disable pretty-printer" have been added.
2697 ** gdb.parameter("directories") is now available.
2699 ** New function gdb.newest_frame returns the newest frame in the
2702 ** The gdb.InferiorThread class has a new "name" attribute. This
2703 holds the thread's name.
2705 ** Python Support for Inferior events.
2706 Python scripts can add observers to be notified of events
2707 occurring in the process being debugged.
2708 The following events are currently supported:
2709 - gdb.events.cont Continue event.
2710 - gdb.events.exited Inferior exited event.
2711 - gdb.events.stop Signal received, and Breakpoint hit events.
2715 ** GDB now puts template parameters in scope when debugging in an
2716 instantiation. For example, if you have:
2718 template<int X> int func (void) { return X; }
2720 then if you step into func<5>, "print X" will show "5". This
2721 feature requires proper debuginfo support from the compiler; it
2722 was added to GCC 4.5.
2724 ** The motion commands "next", "finish", "until", and "advance" now
2725 work better when exceptions are thrown. In particular, GDB will
2726 no longer lose control of the inferior; instead, the GDB will
2727 stop the inferior at the point at which the exception is caught.
2728 This functionality requires a change in the exception handling
2729 code that was introduced in GCC 4.5.
2731 * GDB now follows GCC's rules on accessing volatile objects when
2732 reading or writing target state during expression evaluation.
2733 One notable difference to prior behavior is that "print x = 0"
2734 no longer generates a read of x; the value of the assignment is
2735 now always taken directly from the value being assigned.
2737 * GDB now has some support for using labels in the program's source in
2738 linespecs. For instance, you can use "advance label" to continue
2739 execution to a label.
2741 * GDB now has support for reading and writing a new .gdb_index
2742 section. This section holds a fast index of DWARF debugging
2743 information and can be used to greatly speed up GDB startup and
2744 operation. See the documentation for `save gdb-index' for details.
2746 * The "watch" command now accepts an optional "-location" argument.
2747 When used, this causes GDB to watch the memory referred to by the
2748 expression. Such a watchpoint is never deleted due to it going out
2751 * GDB now supports thread debugging of core dumps on GNU/Linux.
2753 GDB now activates thread debugging using the libthread_db library
2754 when debugging GNU/Linux core dumps, similarly to when debugging
2755 live processes. As a result, when debugging a core dump file, GDB
2756 is now able to display pthread_t ids of threads. For example, "info
2757 threads" shows the same output as when debugging the process when it
2758 was live. In earlier releases, you'd see something like this:
2761 * 1 LWP 6780 main () at main.c:10
2763 While now you see this:
2766 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2768 It is also now possible to inspect TLS variables when debugging core
2771 When debugging a core dump generated on a machine other than the one
2772 used to run GDB, you may need to point GDB at the correct
2773 libthread_db library with the "set libthread-db-search-path"
2774 command. See the user manual for more details on this command.
2776 * When natively debugging programs on PowerPC BookE processors running
2777 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2778 which stop execution of the inferior whenever it executes an instruction
2779 at any address within the specified range. See the "PowerPC Embedded"
2780 section in the user manual for more details.
2782 * New features in the GDB remote stub, GDBserver
2784 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2785 and i686 LynxOS (version 5.x).
2787 ** GDBserver is now supported on Blackfin Linux.
2789 * New native configurations
2791 ia64 HP-UX ia64-*-hpux*
2795 Analog Devices, Inc. Blackfin Processor bfin-*
2797 * Ada task switching is now supported on sparc-elf targets when
2798 debugging a program using the Ravenscar Profile. For more information,
2799 see the "Tasking Support when using the Ravenscar Profile" section
2800 in the GDB user manual.
2802 * Guile support was removed.
2804 * New features in the GNU simulator
2806 ** The --map-info flag lists all known core mappings.
2808 ** CFI flashes may be simulated via the "cfi" device.
2810 *** Changes in GDB 7.2
2812 * Shared library support for remote targets by default
2814 When GDB is configured for a generic, non-OS specific target, like
2815 for example, --target=arm-eabi or one of the many *-*-elf targets,
2816 GDB now queries remote stubs for loaded shared libraries using the
2817 `qXfer:libraries:read' packet. Previously, shared library support
2818 was always disabled for such configurations.
2822 ** Argument Dependent Lookup (ADL)
2824 In C++ ADL lookup directs function search to the namespaces of its
2825 arguments even if the namespace has not been imported.
2835 Here the compiler will search for `foo' in the namespace of 'b'
2836 and find A::foo. GDB now supports this. This construct is commonly
2837 used in the Standard Template Library for operators.
2839 ** Improved User Defined Operator Support
2841 In addition to member operators, GDB now supports lookup of operators
2842 defined in a namespace and imported with a `using' directive, operators
2843 defined in the global scope, operators imported implicitly from an
2844 anonymous namespace, and the ADL operators mentioned in the previous
2846 GDB now also supports proper overload resolution for all the previously
2847 mentioned flavors of operators.
2849 ** static const class members
2851 Printing of static const class members that are initialized in the
2852 class definition has been fixed.
2854 * Windows Thread Information Block access.
2856 On Windows targets, GDB now supports displaying the Windows Thread
2857 Information Block (TIB) structure. This structure is visible either
2858 by using the new command `info w32 thread-information-block' or, by
2859 dereferencing the new convenience variable named `$_tlb', a
2860 thread-specific pointer to the TIB. This feature is also supported
2861 when remote debugging using GDBserver.
2863 * Static tracepoints
2865 Static tracepoints are calls in the user program into a tracing
2866 library. One such library is a port of the LTTng kernel tracer to
2867 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2868 When debugging with GDBserver, GDB now supports combining the GDB
2869 tracepoint machinery with such libraries. For example: the user can
2870 use GDB to probe a static tracepoint marker (a call from the user
2871 program into the tracing library) with the new "strace" command (see
2872 "New commands" below). This creates a "static tracepoint" in the
2873 breakpoint list, that can be manipulated with the same feature set
2874 as fast and regular tracepoints. E.g., collect registers, local and
2875 global variables, collect trace state variables, and define
2876 tracepoint conditions. In addition, the user can collect extra
2877 static tracepoint marker specific data, by collecting the new
2878 $_sdata internal variable. When analyzing the trace buffer, you can
2879 inspect $_sdata like any other variable available to GDB. For more
2880 information, see the "Tracepoints" chapter in GDB user manual. New
2881 remote packets have been defined to support static tracepoints, see
2882 the "New remote packets" section below.
2884 * Better reconstruction of tracepoints after disconnected tracing
2886 GDB will attempt to download the original source form of tracepoint
2887 definitions when starting a trace run, and then will upload these
2888 upon reconnection to the target, resulting in a more accurate
2889 reconstruction of the tracepoints that are in use on the target.
2893 You can now exercise direct control over the ways that GDB can
2894 affect your program. For instance, you can disallow the setting of
2895 breakpoints, so that the program can run continuously (assuming
2896 non-stop mode). In addition, the "observer" variable is available
2897 to switch all of the different controls; in observer mode, GDB
2898 cannot affect the target's behavior at all, which is useful for
2899 tasks like diagnosing live systems in the field.
2901 * The new convenience variable $_thread holds the number of the
2904 * New remote packets
2908 Return the address of the Windows Thread Information Block of a given thread.
2912 In response to several of the tracepoint packets, the target may now
2913 also respond with a number of intermediate `qRelocInsn' request
2914 packets before the final result packet, to have GDB handle
2915 relocating an instruction to execute at a different address. This
2916 is particularly useful for stubs that support fast tracepoints. GDB
2917 reports support for this feature in the qSupported packet.
2921 List static tracepoint markers in the target program.
2925 List static tracepoint markers at a given address in the target
2928 qXfer:statictrace:read
2930 Read the static trace data collected (by a `collect $_sdata'
2931 tracepoint action). The remote stub reports support for this packet
2932 to gdb's qSupported query.
2936 Send the current settings of GDB's permission flags.
2940 Send part of the source (textual) form of a tracepoint definition,
2941 which includes location, conditional, and action list.
2943 * The source command now accepts a -s option to force searching for the
2944 script in the source search path even if the script name specifies
2947 * New features in the GDB remote stub, GDBserver
2949 - GDBserver now support tracepoints (including fast tracepoints, and
2950 static tracepoints). The feature is currently supported by the
2951 i386-linux and amd64-linux builds. See the "Tracepoints support
2952 in gdbserver" section in the manual for more information.
2954 GDBserver JIT compiles the tracepoint's conditional agent
2955 expression bytecode into native code whenever possible for low
2956 overhead dynamic tracepoints conditionals. For such tracepoints,
2957 an expression that examines program state is evaluated when the
2958 tracepoint is reached, in order to determine whether to capture
2959 trace data. If the condition is simple and false, processing the
2960 tracepoint finishes very quickly and no data is gathered.
2962 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2963 for static tracepoints support.
2965 - GDBserver now supports x86_64 Windows 64-bit debugging.
2967 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2968 it understands register description.
2970 * The --batch flag now disables pagination and queries.
2972 * X86 general purpose registers
2974 GDB now supports reading/writing byte, word and double-word x86
2975 general purpose registers directly. This means you can use, say,
2976 $ah or $ax to refer, respectively, to the byte register AH and
2977 16-bit word register AX that are actually portions of the 32-bit
2978 register EAX or 64-bit register RAX.
2980 * The `commands' command now accepts a range of breakpoints to modify.
2981 A plain `commands' following a command that creates multiple
2982 breakpoints affects all the breakpoints set by that command. This
2983 applies to breakpoints set by `rbreak', and also applies when a
2984 single `break' command creates multiple breakpoints (e.g.,
2985 breakpoints on overloaded c++ functions).
2987 * The `rbreak' command now accepts a filename specification as part of
2988 its argument, limiting the functions selected by the regex to those
2989 in the specified file.
2991 * Support for remote debugging Windows and SymbianOS shared libraries
2992 from Unix hosts has been improved. Non Windows GDB builds now can
2993 understand target reported file names that follow MS-DOS based file
2994 system semantics, such as file names that include drive letters and
2995 use the backslash character as directory separator. This makes it
2996 possible to transparently use the "set sysroot" and "set
2997 solib-search-path" on Unix hosts to point as host copies of the
2998 target's shared libraries. See the new command "set
2999 target-file-system-kind" described below, and the "Commands to
3000 specify files" section in the user manual for more information.
3004 eval template, expressions...
3005 Convert the values of one or more expressions under the control
3006 of the string template to a command line, and call it.
3008 set target-file-system-kind unix|dos-based|auto
3009 show target-file-system-kind
3010 Set or show the assumed file system kind for target reported file
3013 save breakpoints <filename>
3014 Save all current breakpoint definitions to a file suitable for use
3015 in a later debugging session. To read the saved breakpoint
3016 definitions, use the `source' command.
3018 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3021 info static-tracepoint-markers
3022 Display information about static tracepoint markers in the target.
3024 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3025 Define a static tracepoint by probing a marker at the given
3026 function, line, address, or marker ID.
3030 Enable and disable observer mode.
3032 set may-write-registers on|off
3033 set may-write-memory on|off
3034 set may-insert-breakpoints on|off
3035 set may-insert-tracepoints on|off
3036 set may-insert-fast-tracepoints on|off
3037 set may-interrupt on|off
3038 Set individual permissions for GDB effects on the target. Note that
3039 some of these settings can have undesirable or surprising
3040 consequences, particularly when changed in the middle of a session.
3041 For instance, disabling the writing of memory can prevent
3042 breakpoints from being inserted, cause single-stepping to fail, or
3043 even crash your program, if you disable after breakpoints have been
3044 inserted. However, GDB should not crash.
3046 set record memory-query on|off
3047 show record memory-query
3048 Control whether to stop the inferior if memory changes caused
3049 by an instruction cannot be recorded.
3054 The disassemble command now supports "start,+length" form of two arguments.
3058 ** GDB now provides a new directory location, called the python directory,
3059 where Python scripts written for GDB can be installed. The location
3060 of that directory is <data-directory>/python, where <data-directory>
3061 is the GDB data directory. For more details, see section `Scripting
3062 GDB using Python' in the manual.
3064 ** The GDB Python API now has access to breakpoints, symbols, symbol
3065 tables, program spaces, inferiors, threads and frame's code blocks.
3066 Additionally, GDB Parameters can now be created from the API, and
3067 manipulated via set/show in the CLI.
3069 ** New functions gdb.target_charset, gdb.target_wide_charset,
3070 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3072 ** New exception gdb.GdbError.
3074 ** Pretty-printers are now also looked up in the current program space.
3076 ** Pretty-printers can now be individually enabled and disabled.
3078 ** GDB now looks for names of Python scripts to auto-load in a
3079 special section named `.debug_gdb_scripts', in addition to looking
3080 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3082 * Tracepoint actions were unified with breakpoint commands. In particular,
3083 there are no longer differences in "info break" output for breakpoints and
3084 tracepoints and the "commands" command can be used for both tracepoints and
3085 regular breakpoints.
3089 ARM Symbian arm*-*-symbianelf*
3091 * D language support.
3092 GDB now supports debugging programs written in the D programming
3095 * GDB now supports the extended ptrace interface for PowerPC which is
3096 available since Linux kernel version 2.6.34. This automatically enables
3097 any hardware breakpoints and additional hardware watchpoints available in
3098 the processor. The old ptrace interface exposes just one hardware
3099 watchpoint and no hardware breakpoints.
3101 * GDB is now able to use the Data Value Compare (DVC) register available on
3102 embedded PowerPC processors to implement in hardware simple watchpoint
3103 conditions of the form:
3105 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3107 This works in native GDB running on Linux kernels with the extended ptrace
3108 interface mentioned above.
3110 *** Changes in GDB 7.1
3114 ** Namespace Support
3116 GDB now supports importing of namespaces in C++. This enables the
3117 user to inspect variables from imported namespaces. Support for
3118 namepace aliasing has also been added. So, if a namespace is
3119 aliased in the current scope (e.g. namepace C=A; ) the user can
3120 print variables using the alias (e.g. (gdb) print C::x).
3124 All known bugs relating to the printing of virtual base class were
3125 fixed. It is now possible to call overloaded static methods using a
3130 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3131 and reinterpret_cast<> are now handled by the C++ expression parser.
3135 Xilinx MicroBlaze microblaze-*-*
3140 Xilinx MicroBlaze microblaze
3143 * Multi-program debugging.
3145 GDB now has support for multi-program (a.k.a. multi-executable or
3146 multi-exec) debugging. This allows for debugging multiple inferiors
3147 simultaneously each running a different program under the same GDB
3148 session. See "Debugging Multiple Inferiors and Programs" in the
3149 manual for more information. This implied some user visible changes
3150 in the multi-inferior support. For example, "info inferiors" now
3151 lists inferiors that are not running yet or that have exited
3152 already. See also "New commands" and "New options" below.
3154 * New tracing features
3156 GDB's tracepoint facility now includes several new features:
3158 ** Trace state variables
3160 GDB tracepoints now include support for trace state variables, which
3161 are variables managed by the target agent during a tracing
3162 experiment. They are useful for tracepoints that trigger each
3163 other, so for instance one tracepoint can count hits in a variable,
3164 and then a second tracepoint has a condition that is true when the
3165 count reaches a particular value. Trace state variables share the
3166 $-syntax of GDB convenience variables, and can appear in both
3167 tracepoint actions and condition expressions. Use the "tvariable"
3168 command to create, and "info tvariables" to view; see "Trace State
3169 Variables" in the manual for more detail.
3173 GDB now includes an option for defining fast tracepoints, which
3174 targets may implement more efficiently, such as by installing a jump
3175 into the target agent rather than a trap instruction. The resulting
3176 speedup can be by two orders of magnitude or more, although the
3177 tradeoff is that some program locations on some target architectures
3178 might not allow fast tracepoint installation, for instance if the
3179 instruction to be replaced is shorter than the jump. To request a
3180 fast tracepoint, use the "ftrace" command, with syntax identical to
3181 the regular trace command.
3183 ** Disconnected tracing
3185 It is now possible to detach GDB from the target while it is running
3186 a trace experiment, then reconnect later to see how the experiment
3187 is going. In addition, a new variable disconnected-tracing lets you
3188 tell the target agent whether to continue running a trace if the
3189 connection is lost unexpectedly.
3193 GDB now has the ability to save the trace buffer into a file, and
3194 then use that file as a target, similarly to you can do with
3195 corefiles. You can select trace frames, print data that was
3196 collected in them, and use tstatus to display the state of the
3197 tracing run at the moment that it was saved. To create a trace
3198 file, use "tsave <filename>", and to use it, do "target tfile
3201 ** Circular trace buffer
3203 You can ask the target agent to handle the trace buffer as a
3204 circular buffer, discarding the oldest trace frames to make room for
3205 newer ones, by setting circular-trace-buffer to on. This feature may
3206 not be available for all target agents.
3211 The disassemble command, when invoked with two arguments, now requires
3212 the arguments to be comma-separated.
3215 The info variables command now displays variable definitions. Files
3216 which only declare a variable are not shown.
3219 The source command is now capable of sourcing Python scripts.
3220 This feature is dependent on the debugger being build with Python
3223 Related to this enhancement is also the introduction of a new command
3224 "set script-extension" (see below).
3226 * New commands (for set/show, see "New options" below)
3228 record save [<FILENAME>]
3229 Save a file (in core file format) containing the process record
3230 execution log for replay debugging at a later time.
3232 record restore <FILENAME>
3233 Restore the process record execution log that was saved at an
3234 earlier time, for replay debugging.
3236 add-inferior [-copies <N>] [-exec <FILENAME>]
3239 clone-inferior [-copies <N>] [ID]
3240 Make a new inferior ready to execute the same program another
3241 inferior has loaded.
3246 maint info program-spaces
3247 List the program spaces loaded into GDB.
3249 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3250 show remote interrupt-sequence
3251 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3252 as the sequence to the remote target in order to interrupt the execution.
3253 Ctrl-C is a default. Some system prefers BREAK which is high level of
3254 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3255 Magic SysRq g. It is BREAK signal and character 'g'.
3257 set remote interrupt-on-connect [on | off]
3258 show remote interrupt-on-connect
3259 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3260 remote target when gdb connects to it. This is needed when you debug
3263 set remotebreak [on | off]
3265 Deprecated. Use "set/show remote interrupt-sequence" instead.
3267 tvariable $NAME [ = EXP ]
3268 Create or modify a trace state variable.
3271 List trace state variables and their values.
3273 delete tvariable $NAME ...
3274 Delete one or more trace state variables.
3277 Evaluate the given expressions without collecting anything into the
3278 trace buffer. (Valid in tracepoint actions only.)
3280 ftrace FN / FILE:LINE / *ADDR
3281 Define a fast tracepoint at the given function, line, or address.
3283 * New expression syntax
3285 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3286 GDB now parses 0b101010 identically with 42.
3290 set follow-exec-mode new|same
3291 show follow-exec-mode
3292 Control whether GDB reuses the same inferior across an exec call or
3293 creates a new one. This is useful to be able to restart the old
3294 executable after the inferior having done an exec call.
3296 set default-collect EXPR, ...
3297 show default-collect
3298 Define a list of expressions to be collected at each tracepoint.
3299 This is a useful way to ensure essential items are not overlooked,
3300 such as registers or a critical global variable.
3302 set disconnected-tracing
3303 show disconnected-tracing
3304 If set to 1, the target is instructed to continue tracing if it
3305 loses its connection to GDB. If 0, the target is to stop tracing
3308 set circular-trace-buffer
3309 show circular-trace-buffer
3310 If set to on, the target is instructed to use a circular trace buffer
3311 and discard the oldest trace frames instead of stopping the trace due
3312 to a full trace buffer. If set to off, the trace stops when the buffer
3313 fills up. Some targets may not support this.
3315 set script-extension off|soft|strict
3316 show script-extension
3317 If set to "off", the debugger does not perform any script language
3318 recognition, and all sourced files are assumed to be GDB scripts.
3319 If set to "soft" (the default), files are sourced according to
3320 filename extension, falling back to GDB scripts if the first
3322 If set to "strict", files are sourced according to filename extension.
3324 set ada trust-PAD-over-XVS on|off
3325 show ada trust-PAD-over-XVS
3326 If off, activate a workaround against a bug in the debugging information
3327 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3328 the GCC sources for more information about the GNAT encoding and
3329 PAD types in particular). It is always safe to set this option to
3330 off, but this introduces a slight performance penalty. The default
3333 * Python API Improvements
3335 ** GDB provides the new class gdb.LazyString. This is useful in
3336 some pretty-printing cases. The new method gdb.Value.lazy_string
3337 provides a simple way to create objects of this type.
3339 ** The fields returned by gdb.Type.fields now have an
3340 `is_base_class' attribute.
3342 ** The new method gdb.Type.range returns the range of an array type.
3344 ** The new method gdb.parse_and_eval can be used to parse and
3345 evaluate an expression.
3347 * New remote packets
3350 Define a trace state variable.
3353 Get the current value of a trace state variable.
3356 Set desired tracing behavior upon disconnection.
3359 Set the trace buffer to be linear or circular.
3362 Get data about the tracepoints currently in use.
3366 Process record now works correctly with hardware watchpoints.
3368 Multiple bug fixes have been made to the mips-irix port, making it
3369 much more reliable. In particular:
3370 - Debugging threaded applications is now possible again. Previously,
3371 GDB would hang while starting the program, or while waiting for
3372 the program to stop at a breakpoint.
3373 - Attaching to a running process no longer hangs.
3374 - An error occurring while loading a core file has been fixed.
3375 - Changing the value of the PC register now works again. This fixes
3376 problems observed when using the "jump" command, or when calling
3377 a function from GDB, or even when assigning a new value to $pc.
3378 - With the "finish" and "return" commands, the return value for functions
3379 returning a small array is now correctly printed.
3380 - It is now possible to break on shared library code which gets executed
3381 during a shared library init phase (code executed while executing
3382 their .init section). Previously, the breakpoint would have no effect.
3383 - GDB is now able to backtrace through the signal handler for
3384 non-threaded programs.
3386 PIE (Position Independent Executable) programs debugging is now supported.
3387 This includes debugging execution of PIC (Position Independent Code) shared
3388 libraries although for that, it should be possible to run such libraries as an
3391 *** Changes in GDB 7.0
3393 * GDB now has an interface for JIT compilation. Applications that
3394 dynamically generate code can create symbol files in memory and register
3395 them with GDB. For users, the feature should work transparently, and
3396 for JIT developers, the interface is documented in the GDB manual in the
3397 "JIT Compilation Interface" chapter.
3399 * Tracepoints may now be conditional. The syntax is as for
3400 breakpoints; either an "if" clause appended to the "trace" command,
3401 or the "condition" command is available. GDB sends the condition to
3402 the target for evaluation using the same bytecode format as is used
3403 for tracepoint actions.
3405 * The disassemble command now supports: an optional /r modifier, print the
3406 raw instructions in hex as well as in symbolic form, and an optional /m
3407 modifier to print mixed source+assembly.
3409 * Process record and replay
3411 In a architecture environment that supports ``process record and
3412 replay'', ``process record and replay'' target can record a log of
3413 the process execution, and replay it with both forward and reverse
3416 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3417 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3418 set execution-direction {forward|reverse}, for targets that support
3421 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3422 feature is available with a native GDB running on kernel version
3425 * GDB now has support for multi-byte and wide character sets on the
3426 target. Strings whose character type is wchar_t, char16_t, or
3427 char32_t are now correctly printed. GDB supports wide- and unicode-
3428 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3429 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3430 `printf'. This feature requires iconv to work properly; if your
3431 system does not have a working iconv, GDB can use GNU libiconv. See
3432 the installation instructions for more information.
3434 * GDB now supports automatic retrieval of shared library files from
3435 remote targets. To use this feature, specify a system root that begins
3436 with the `remote:' prefix, either via the `set sysroot' command or via
3437 the `--with-sysroot' configure-time option.
3439 * "info sharedlibrary" now takes an optional regex of libraries to show,
3440 and it now reports if a shared library has no debugging information.
3442 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3443 now complete on file names.
3445 * When completing in expressions, gdb will attempt to limit
3446 completions to allowable structure or union fields, where appropriate.
3447 For instance, consider:
3449 # struct example { int f1; double f2; };
3450 # struct example variable;
3453 If the user types TAB at the end of this command line, the available
3454 completions will be "f1" and "f2".
3456 * Inlined functions are now supported. They show up in backtraces, and
3457 the "step", "next", and "finish" commands handle them automatically.
3459 * GDB now supports the token-splicing (##) and stringification (#)
3460 operators when expanding macros. It also supports variable-arity
3463 * GDB now supports inspecting extra signal information, exported by
3464 the new $_siginfo convenience variable. The feature is currently
3465 implemented on linux ARM, i386 and amd64.
3467 * GDB can now display the VFP floating point registers and NEON vector
3468 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3469 can provide these registers (requires Linux 2.6.30 or later). Remote
3470 and simulator targets may also provide them.
3472 * New remote packets
3475 Search memory for a sequence of bytes.
3478 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3479 operation over reliable transport links. Use of this packet is
3480 controlled by the `set remote noack-packet' command.
3483 Kill the process with the specified process ID. Use this in preference
3484 to `k' when multiprocess protocol extensions are supported.
3487 Obtains additional operating system information
3491 Read or write additional signal information.
3493 * Removed remote protocol undocumented extension
3495 An undocumented extension to the remote protocol's `S' stop reply
3496 packet that permited the stub to pass a process id was removed.
3497 Remote servers should use the `T' stop reply packet instead.
3499 * GDB now supports multiple function calling conventions according to the
3500 DWARF-2 DW_AT_calling_convention function attribute.
3502 * The SH target utilizes the aforementioned change to distinguish between gcc
3503 and Renesas calling convention. It also adds the new CLI commands
3504 `set/show sh calling-convention'.
3506 * GDB can now read compressed debug sections, as produced by GNU gold
3507 with the --compress-debug-sections=zlib flag.
3509 * 64-bit core files are now supported on AIX.
3511 * Thread switching is now supported on Tru64.
3513 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3514 which will be allocated using malloc later in program execution.
3516 * The qXfer:libraries:read remote procotol packet now allows passing a
3517 list of section offsets.
3519 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3520 conditions handling signals delivered during attach or thread creation
3521 have also been fixed.
3523 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3524 From the user's standpoint, all unqualified instances of True and False
3525 are treated as the standard definitions, regardless of context.
3527 * GDB now parses C++ symbol and type names more flexibly. For
3530 template<typename T> class C { };
3533 GDB will now correctly handle all of:
3535 ptype C<char const *>
3536 ptype C<char const*>
3537 ptype C<const char *>
3538 ptype C<const char*>
3540 * New features in the GDB remote stub, gdbserver
3542 - The "--wrapper" command-line argument tells gdbserver to use a
3543 wrapper program to launch programs for debugging.
3545 - On PowerPC and S/390 targets, it is now possible to use a single
3546 gdbserver executable to debug both 32-bit and 64-bit programs.
3547 (This requires gdbserver itself to be built as a 64-bit executable.)
3549 - gdbserver uses the new noack protocol mode for TCP connections to
3550 reduce communications latency, if also supported and enabled in GDB.
3552 - Support for the sparc64-linux-gnu target is now included in
3555 - The amd64-linux build of gdbserver now supports debugging both
3556 32-bit and 64-bit programs.
3558 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3559 now support hardware watchpoints, and will use them automatically
3564 GDB now has support for scripting using Python. Whether this is
3565 available is determined at configure time.
3567 New GDB commands can now be written in Python.
3569 * Ada tasking support
3571 Ada tasks can now be inspected in GDB. The following commands have
3575 Print the list of Ada tasks.
3577 Print detailed information about task number N.
3579 Print the task number of the current task.
3581 Switch the context of debugging to task number N.
3583 * Support for user-defined prefixed commands. The "define" command can
3584 add new commands to existing prefixes, e.g. "target".
3586 * Multi-inferior, multi-process debugging.
3588 GDB now has generalized support for multi-inferior debugging. See
3589 "Debugging Multiple Inferiors" in the manual for more information.
3590 Although availability still depends on target support, the command
3591 set is more uniform now. The GNU/Linux specific multi-forks support
3592 has been migrated to this new framework. This implied some user
3593 visible changes; see "New commands" and also "Removed commands"
3596 * Target descriptions can now describe the target OS ABI. See the
3597 "Target Description Format" section in the user manual for more
3600 * Target descriptions can now describe "compatible" architectures
3601 to indicate that the target can execute applications for a different
3602 architecture in addition to those for the main target architecture.
3603 See the "Target Description Format" section in the user manual for
3606 * Multi-architecture debugging.
3608 GDB now includes general supports for debugging applications on
3609 hybrid systems that use more than one single processor architecture
3610 at the same time. Each such hybrid architecture still requires
3611 specific support to be added. The only hybrid architecture supported
3612 in this version of GDB is the Cell Broadband Engine.
3614 * GDB now supports integrated debugging of Cell/B.E. applications that
3615 use both the PPU and SPU architectures. To enable support for hybrid
3616 Cell/B.E. debugging, you need to configure GDB to support both the
3617 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3618 --enable-targets configure option.
3620 * Non-stop mode debugging.
3622 For some targets, GDB now supports an optional mode of operation in
3623 which you can examine stopped threads while other threads continue
3624 to execute freely. This is referred to as non-stop mode, with the
3625 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3626 section in the user manual for more information.
3628 To be able to support remote non-stop debugging, a remote stub needs
3629 to implement the non-stop mode remote protocol extensions, as
3630 described in the "Remote Non-Stop" section of the user manual. The
3631 GDB remote stub, gdbserver, has been adjusted to support these
3632 extensions on linux targets.
3634 * New commands (for set/show, see "New options" below)
3636 catch syscall [NAME(S) | NUMBER(S)]
3637 Catch system calls. Arguments, which should be names of system
3638 calls or their numbers, mean catch only those syscalls. Without
3639 arguments, every syscall will be caught. When the inferior issues
3640 any of the specified syscalls, GDB will stop and announce the system
3641 call, both when it is called and when its call returns. This
3642 feature is currently available with a native GDB running on the
3643 Linux Kernel, under the following architectures: x86, x86_64,
3644 PowerPC and PowerPC64.
3646 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3648 Search memory for a sequence of bytes.
3650 maint set python print-stack
3651 maint show python print-stack
3652 Show a stack trace when an error is encountered in a Python script.
3655 Invoke CODE by passing it to the Python interpreter.
3660 These allow macros to be defined, undefined, and listed
3664 Show operating system information about processes.
3667 List the inferiors currently under GDB's control.
3670 Switch focus to inferior number NUM.
3673 Detach from inferior number NUM.
3676 Kill inferior number NUM.
3680 set spu stop-on-load
3681 show spu stop-on-load
3682 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3684 set spu auto-flush-cache
3685 show spu auto-flush-cache
3686 Control whether to automatically flush the software-managed cache
3687 during Cell/B.E. debugging.
3689 set sh calling-convention
3690 show sh calling-convention
3691 Control the calling convention used when calling SH target functions.
3694 show debug timestamp
3695 Control display of timestamps with GDB debugging output.
3697 set disassemble-next-line
3698 show disassemble-next-line
3699 Control display of disassembled source lines or instructions when
3702 set remote noack-packet
3703 show remote noack-packet
3704 Set/show the use of remote protocol QStartNoAckMode packet. See above
3705 under "New remote packets."
3707 set remote query-attached-packet
3708 show remote query-attached-packet
3709 Control use of remote protocol `qAttached' (query-attached) packet.
3711 set remote read-siginfo-object
3712 show remote read-siginfo-object
3713 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3716 set remote write-siginfo-object
3717 show remote write-siginfo-object
3718 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3721 set remote reverse-continue
3722 show remote reverse-continue
3723 Control use of remote protocol 'bc' (reverse-continue) packet.
3725 set remote reverse-step
3726 show remote reverse-step
3727 Control use of remote protocol 'bs' (reverse-step) packet.
3729 set displaced-stepping
3730 show displaced-stepping
3731 Control displaced stepping mode. Displaced stepping is a way to
3732 single-step over breakpoints without removing them from the debuggee.
3733 Also known as "out-of-line single-stepping".
3736 show debug displaced
3737 Control display of debugging info for displaced stepping.
3739 maint set internal-error
3740 maint show internal-error
3741 Control what GDB does when an internal error is detected.
3743 maint set internal-warning
3744 maint show internal-warning
3745 Control what GDB does when an internal warning is detected.
3750 Use a wrapper program to launch programs for debugging.
3752 set multiple-symbols (all|ask|cancel)
3753 show multiple-symbols
3754 The value of this variable can be changed to adjust the debugger behavior
3755 when an expression or a breakpoint location contains an ambiguous symbol
3756 name (an overloaded function name, for instance).
3758 set breakpoint always-inserted
3759 show breakpoint always-inserted
3760 Keep breakpoints always inserted in the target, as opposed to inserting
3761 them when resuming the target, and removing them when the target stops.
3762 This option can improve debugger performance on slow remote targets.
3764 set arm fallback-mode (arm|thumb|auto)
3765 show arm fallback-mode
3766 set arm force-mode (arm|thumb|auto)
3768 These commands control how ARM GDB determines whether instructions
3769 are ARM or Thumb. The default for both settings is auto, which uses
3770 the current CPSR value for instructions without symbols; previous
3771 versions of GDB behaved as if "set arm fallback-mode arm".
3773 set disable-randomization
3774 show disable-randomization
3775 Standalone programs run with the virtual address space randomization enabled
3776 by default on some platforms. This option keeps the addresses stable across
3777 multiple debugging sessions.
3781 Control whether other threads are stopped or not when some thread hits
3786 Requests that asynchronous execution is enabled in the target, if available.
3787 In this case, it's possible to resume target in the background, and interact
3788 with GDB while the target is running. "show target-async" displays the
3789 current state of asynchronous execution of the target.
3791 set target-wide-charset
3792 show target-wide-charset
3793 The target-wide-charset is the name of the character set that GDB
3794 uses when printing characters whose type is wchar_t.
3796 set tcp auto-retry (on|off)
3798 set tcp connect-timeout
3799 show tcp connect-timeout
3800 These commands allow GDB to retry failed TCP connections to a remote stub
3801 with a specified timeout period; this is useful if the stub is launched
3802 in parallel with GDB but may not be ready to accept connections immediately.
3804 set libthread-db-search-path
3805 show libthread-db-search-path
3806 Control list of directories which GDB will search for appropriate
3809 set schedule-multiple (on|off)
3810 show schedule-multiple
3811 Allow GDB to resume all threads of all processes or only threads of
3812 the current process.
3816 Use more aggressive caching for accesses to the stack. This improves
3817 performance of remote debugging (particularly backtraces) without
3818 affecting correctness.
3820 set interactive-mode (on|off|auto)
3821 show interactive-mode
3822 Control whether GDB runs in interactive mode (on) or not (off).
3823 When in interactive mode, GDB waits for the user to answer all
3824 queries. Otherwise, GDB does not wait and assumes the default
3825 answer. When set to auto (the default), GDB determines which
3826 mode to use based on the stdin settings.
3831 For program forks, this is replaced by the new more generic `info
3832 inferiors' command. To list checkpoints, you can still use the
3833 `info checkpoints' command, which was an alias for the `info forks'
3837 Replaced by the new `inferior' command. To switch between
3838 checkpoints, you can still use the `restart' command, which was an
3839 alias for the `fork' command.
3842 This is removed, since some targets don't have a notion of
3843 processes. To switch between processes, you can still use the
3844 `inferior' command using GDB's own inferior number.
3847 For program forks, this is replaced by the new more generic `kill
3848 inferior' command. To delete a checkpoint, you can still use the
3849 `delete checkpoint' command, which was an alias for the `delete
3853 For program forks, this is replaced by the new more generic `detach
3854 inferior' command. To detach a checkpoint, you can still use the
3855 `detach checkpoint' command, which was an alias for the `detach
3858 * New native configurations
3860 x86/x86_64 Darwin i[34567]86-*-darwin*
3862 x86_64 MinGW x86_64-*-mingw*
3866 Lattice Mico32 lm32-*
3867 x86 DICOS i[34567]86-*-dicos*
3868 x86_64 DICOS x86_64-*-dicos*
3871 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3872 (mingw32ce) debugging.
3878 These commands were actually not implemented on any target.
3880 *** Changes in GDB 6.8
3882 * New native configurations
3884 NetBSD/hppa hppa*-*netbsd*
3885 Xtensa GNU/Linux xtensa*-*-linux*
3889 NetBSD/hppa hppa*-*-netbsd*
3890 Xtensa GNU/Lunux xtensa*-*-linux*
3892 * Change in command line behavior -- corefiles vs. process ids.
3894 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3895 attaching to process NUMBER fails, GDB no longer attempts to open a
3896 core file named NUMBER. Attaching to a program using the -c option
3897 is no longer supported. Instead, use the '-p' or '--pid' options.
3899 * GDB can now be built as a native debugger for debugging Windows x86
3900 (mingw32) Portable Executable (PE) programs.
3902 * Pending breakpoints no longer change their number when their address
3905 * GDB now supports breakpoints with multiple locations,
3906 including breakpoints on C++ constructors, inside C++ templates,
3907 and in inlined functions.
3909 * GDB's ability to debug optimized code has been improved. GDB more
3910 accurately identifies function bodies and lexical blocks that occupy
3911 more than one contiguous range of addresses.
3913 * Target descriptions can now describe registers for PowerPC.
3915 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3916 registers on PowerPC targets.
3918 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3919 targets even when the libthread_db library is not available.
3921 * The GDB remote stub, gdbserver, now supports the new file transfer
3922 commands (remote put, remote get, and remote delete).
3924 * The GDB remote stub, gdbserver, now supports run and attach in
3925 extended-remote mode.
3927 * hppa*64*-*-hpux11* target broken
3928 The debugger is unable to start a program and fails with the following
3929 error: "Error trying to get information about dynamic linker".
3930 The gdb-6.7 release is also affected.
3932 * GDB now supports the --enable-targets= configure option to allow
3933 building a single GDB executable that supports multiple remote
3934 target architectures.
3936 * GDB now supports debugging C and C++ programs which use the
3937 Decimal Floating Point extension. In addition, the PowerPC target
3938 now has a set of pseudo-registers to inspect decimal float values
3939 stored in two consecutive float registers.
3941 * The -break-insert MI command can optionally create pending
3944 * Improved support for debugging Ada
3945 Many improvements to the Ada language support have been made. These
3947 - Better support for Ada2005 interface types
3948 - Improved handling of arrays and slices in general
3949 - Better support for Taft-amendment types
3950 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3952 - Improved command completion in Ada
3955 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3960 set print frame-arguments (all|scalars|none)
3961 show print frame-arguments
3962 The value of this variable can be changed to control which argument
3963 values should be printed by the debugger when displaying a frame.
3968 Transfer files to and from a remote target, and delete remote files.
3975 Transfer files to and from a remote target, and delete remote files.
3977 * New remote packets
3984 Open, close, read, write, and delete files on the remote system.
3987 Attach to an existing process on the remote system, in extended-remote
3991 Run a new process on the remote system, in extended-remote mode.
3993 *** Changes in GDB 6.7
3995 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3996 bfd, libiberty and opcodes, as revealed by static analysis donated by
3997 Coverity, Inc. (http://scan.coverity.com).
3999 * When looking up multiply-defined global symbols, GDB will now prefer the
4000 symbol definition in the current shared library if it was built using the
4001 -Bsymbolic linker option.
4003 * When the Text User Interface (TUI) is not configured, GDB will now
4004 recognize the -tui command-line option and print a message that the TUI
4007 * The GDB remote stub, gdbserver, now has lower overhead for high
4008 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4010 * GDB for MIPS targets now autodetects whether a remote target provides
4011 32-bit or 64-bit register values.
4013 * Support for C++ member pointers has been improved.
4015 * GDB now understands XML target descriptions, which specify the
4016 target's overall architecture. GDB can read a description from
4017 a local file or over the remote serial protocol.
4019 * Vectors of single-byte data use a new integer type which is not
4020 automatically displayed as character or string data.
4022 * The /s format now works with the print command. It displays
4023 arrays of single-byte integers and pointers to single-byte integers
4026 * Target descriptions can now describe target-specific registers,
4027 for architectures which have implemented the support (currently
4028 only ARM, M68K, and MIPS).
4030 * GDB and the GDB remote stub, gdbserver, now support the XScale
4033 * The GDB remote stub, gdbserver, has been updated to support
4034 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4035 has been rewritten to use the standard GDB remote protocol.
4037 * GDB can now step into C++ functions which are called through thunks.
4039 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4041 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4042 layout. It also supports a TextSeg= and DataSeg= response when only
4043 segment base addresses (rather than offsets) are available.
4045 * The /i format now outputs any trailing branch delay slot instructions
4046 immediately following the last instruction within the count specified.
4048 * The GDB remote protocol "T" stop reply packet now supports a
4049 "library" response. Combined with the new "qXfer:libraries:read"
4050 packet, this response allows GDB to debug shared libraries on targets
4051 where the operating system manages the list of loaded libraries (e.g.
4052 Windows and SymbianOS).
4054 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4055 (DLLs) on Windows and Windows CE targets.
4057 * GDB now supports a faster verification that a .debug file matches its binary
4058 according to its build-id signature, if the signature is present.
4064 Enable or disable hardware flow control (RTS/CTS) on the serial port
4065 when debugging using remote targets.
4067 set mem inaccessible-by-default
4068 show mem inaccessible-by-default
4069 If the target supplies a memory map, for instance via the remote
4070 protocol's "qXfer:memory-map:read" packet, setting this variable
4071 prevents GDB from accessing memory outside the memory map. This
4072 is useful for targets with memory mapped registers or which react
4073 badly to accesses of unmapped address space.
4075 set breakpoint auto-hw
4076 show breakpoint auto-hw
4077 If the target supplies a memory map, for instance via the remote
4078 protocol's "qXfer:memory-map:read" packet, setting this variable
4079 lets GDB use hardware breakpoints automatically for memory regions
4080 where it can not use software breakpoints. This covers both the
4081 "break" command and internal breakpoints used for other commands
4082 including "next" and "finish".
4085 catch exception unhandled
4086 Stop the program execution when Ada exceptions are raised.
4089 Stop the program execution when an Ada assertion failed.
4093 Set an alternate system root for target files. This is a more
4094 general version of "set solib-absolute-prefix", which is now
4095 an alias to "set sysroot".
4098 Provide extended SPU facility status information. This set of
4099 commands is available only when debugging the Cell/B.E. SPU
4102 * New native configurations
4104 OpenBSD/sh sh*-*openbsd*
4107 unset tdesc filename
4109 Use the specified local file as an XML target description, and do
4110 not query the target for its built-in description.
4114 OpenBSD/sh sh*-*-openbsd*
4115 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4116 Toshiba Media Processor mep-elf
4118 * New remote packets
4121 Ignore the specified signals; pass them directly to the debugged program
4122 without stopping other threads or reporting them to GDB.
4124 qXfer:features:read:
4125 Read an XML target description from the target, which describes its
4130 Read or write contents of an spufs file on the target system. These
4131 packets are available only on the Cell/B.E. SPU architecture.
4133 qXfer:libraries:read:
4134 Report the loaded shared libraries. Combined with new "T" packet
4135 response, this packet allows GDB to debug shared libraries on
4136 targets where the operating system manages the list of loaded
4137 libraries (e.g. Windows and SymbianOS).
4141 Support for these obsolete configurations has been removed.
4149 i[34567]86-*-lynxos*
4150 i[34567]86-*-netware*
4151 i[34567]86-*-sco3.2v5*
4152 i[34567]86-*-sco3.2v4*
4154 i[34567]86-*-sysv4.2*
4157 i[34567]86-*-unixware2*
4158 i[34567]86-*-unixware*
4167 * Other removed features
4174 Various m68k-only ROM monitors.
4181 Various Renesas ROM monitors and debugging interfaces for SH and
4186 Support for a Macraigor serial interface to on-chip debugging.
4187 GDB does not directly support the newer parallel or USB
4192 A debug information format. The predecessor to DWARF 2 and
4193 DWARF 3, which are still supported.
4195 Support for the HP aCC compiler on HP-UX/PA-RISC
4197 SOM-encapsulated symbolic debugging information, automatic
4198 invocation of pxdb, and the aCC custom C++ ABI. This does not
4199 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4200 with aCC can still be debugged on an assembly level.
4202 MIPS ".pdr" sections
4204 A MIPS-specific format used to describe stack frame layout
4205 in debugging information.
4209 GDB could work with an older version of Guile to debug
4210 the interpreter and Scheme programs running in it.
4212 set mips stack-arg-size
4213 set mips saved-gpreg-size
4215 Use "set mips abi" to control parameter passing for MIPS.
4217 *** Changes in GDB 6.6
4222 Cell Broadband Engine SPU spu-elf
4224 * GDB can now be configured as a cross-debugger targeting native Windows
4225 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4226 running on a Windows system over TCP/IP to debug Windows programs.
4228 * The GDB remote stub, gdbserver, has been updated to support Windows and
4229 Cygwin debugging. Both single-threaded and multi-threaded programs are
4232 * The "set trust-readonly-sections" command works again. This command was
4233 broken in GDB 6.3, 6.4, and 6.5.
4235 * The "load" command now supports writing to flash memory, if the remote
4236 stub provides the required support.
4238 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4239 longer requires symbolic debug information (e.g. DWARF-2).
4244 unset substitute-path
4245 show substitute-path
4246 Manage a list of substitution rules that GDB uses to rewrite the name
4247 of the directories where the sources are located. This can be useful
4248 for instance when the sources were moved to a different location
4249 between compilation and debugging.
4253 Print each CLI command as it is executed. Each command is prefixed with
4254 a number of `+' symbols representing the nesting depth.
4255 The source command now has a `-v' option to enable the same feature.
4259 The ARM Demon monitor support (RDP protocol, "target rdp").
4261 Kernel Object Display, an embedded debugging feature which only worked with
4262 an obsolete version of Cisco IOS.
4264 The 'set download-write-size' and 'show download-write-size' commands.
4266 * New remote packets
4269 Tell a stub about GDB client features, and request remote target features.
4270 The first feature implemented is PacketSize, which allows the target to
4271 specify the size of packets it can handle - to minimize the number of
4272 packets required and improve performance when connected to a remote
4276 Fetch an OS auxilliary vector from the remote stub. This packet is a
4277 more efficient replacement for qPart:auxv:read.
4279 qXfer:memory-map:read:
4280 Fetch a memory map from the remote stub, including information about
4281 RAM, ROM, and flash memory devices.
4286 Erase and program a flash memory device.
4288 * Removed remote packets
4291 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4292 used it, and only gdbserver implemented it.
4294 *** Changes in GDB 6.5
4298 Renesas M32C/M16C m32c-elf
4300 Morpho Technologies ms1 ms1-elf
4304 init-if-undefined Initialize a convenience variable, but
4305 only if it doesn't already have a value.
4307 The following commands are presently only implemented for native GNU/Linux:
4309 checkpoint Save a snapshot of the program state.
4311 restart <n> Return the program state to a
4312 previously saved state.
4314 info checkpoints List currently saved checkpoints.
4316 delete-checkpoint <n> Delete a previously saved checkpoint.
4318 set|show detach-on-fork Tell gdb whether to detach from a newly
4319 forked process, or to keep debugging it.
4321 info forks List forks of the user program that
4322 are available to be debugged.
4324 fork <n> Switch to debugging one of several
4325 forks of the user program that are
4326 available to be debugged.
4328 delete-fork <n> Delete a fork from the list of forks
4329 that are available to be debugged (and
4330 kill the forked process).
4332 detach-fork <n> Delete a fork from the list of forks
4333 that are available to be debugged (and
4334 allow the process to continue).
4338 Morpho Technologies ms2 ms1-elf
4340 * Improved Windows host support
4342 GDB now builds as a cross debugger hosted on i686-mingw32, including
4343 native console support, and remote communications using either
4344 network sockets or serial ports.
4346 * Improved Modula-2 language support
4348 GDB can now print most types in the Modula-2 syntax. This includes:
4349 basic types, set types, record types, enumerated types, range types,
4350 pointer types and ARRAY types. Procedure var parameters are correctly
4351 printed and hexadecimal addresses and character constants are also
4352 written in the Modula-2 syntax. Best results can be obtained by using
4353 GNU Modula-2 together with the -gdwarf-2 command line option.
4357 The ARM rdi-share module.
4359 The Netware NLM debug server.
4361 *** Changes in GDB 6.4
4363 * New native configurations
4365 OpenBSD/arm arm*-*-openbsd*
4366 OpenBSD/mips64 mips64-*-openbsd*
4370 Morpho Technologies ms1 ms1-elf
4372 * New command line options
4374 --batch-silent As for --batch, but totally silent.
4375 --return-child-result The debugger will exist with the same value
4376 the child (debugged) program exited with.
4377 --eval-command COMMAND, -ex COMMAND
4378 Execute a single GDB CLI command. This may be
4379 specified multiple times and in conjunction
4380 with the --command (-x) option.
4382 * Deprecated commands removed
4384 The following commands, that were deprecated in 2000, have been
4388 set|show arm disassembly-flavor set|show arm disassembler
4389 othernames set arm disassembler
4390 set|show remotedebug set|show debug remote
4391 set|show archdebug set|show debug arch
4392 set|show eventdebug set|show debug event
4395 * New BSD user-level threads support
4397 It is now possible to debug programs using the user-level threads
4398 library on OpenBSD and FreeBSD. Currently supported (target)
4401 FreeBSD/amd64 x86_64-*-freebsd*
4402 FreeBSD/i386 i386-*-freebsd*
4403 OpenBSD/i386 i386-*-openbsd*
4405 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4406 are not yet supported.
4408 * New support for Matsushita MN10300 w/sim added
4409 (Work in progress). mn10300-elf.
4411 * REMOVED configurations and files
4413 VxWorks and the XDR protocol *-*-vxworks
4414 Motorola MCORE mcore-*-*
4415 National Semiconductor NS32000 ns32k-*-*
4417 * New "set print array-indexes" command
4419 After turning this setting "on", GDB prints the index of each element
4420 when displaying arrays. The default is "off" to preserve the previous
4423 * VAX floating point support
4425 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4427 * User-defined command support
4429 In addition to using $arg0..$arg9 for argument passing, it is now possible
4430 to use $argc to determine now many arguments have been passed. See the
4431 section on user-defined commands in the user manual for more information.
4433 *** Changes in GDB 6.3:
4435 * New command line option
4437 GDB now accepts -l followed by a number to set the timeout for remote
4440 * GDB works with GCC -feliminate-dwarf2-dups
4442 GDB now supports a more compact representation of DWARF-2 debug
4443 information using DW_FORM_ref_addr references. These are produced
4444 by GCC with the option -feliminate-dwarf2-dups and also by some
4445 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4446 to use -feliminate-dwarf2-dups.
4448 * Internationalization
4450 When supported by the host system, GDB will be built with
4451 internationalization (libintl). The task of marking up the sources is
4452 continued, we're looking forward to our first translation.
4456 Initial support for debugging programs compiled with the GNAT
4457 implementation of the Ada programming language has been integrated
4458 into GDB. In this release, support is limited to expression evaluation.
4460 * New native configurations
4462 GNU/Linux/m32r m32r-*-linux-gnu
4466 GDB's remote protocol now includes support for the 'p' packet. This
4467 packet is used to fetch individual registers from a remote inferior.
4469 * END-OF-LIFE registers[] compatibility module
4471 GDB's internal register infrastructure has been completely rewritten.
4472 The new infrastructure making possible the implementation of key new
4473 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4476 GDB 6.3 will be the last release to include the the registers[]
4477 compatibility module that allowed out-of-date configurations to
4478 continue to work. This change directly impacts the following
4488 powerpc bdm protocol
4490 Unless there is activity to revive these configurations, they will be
4491 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4493 * OBSOLETE configurations and files
4495 Configurations that have been declared obsolete in this release have
4496 been commented out. Unless there is activity to revive these
4497 configurations, the next release of GDB will have their sources
4498 permanently REMOVED.
4507 *** Changes in GDB 6.2.1:
4509 * MIPS `break main; run' gave an heuristic-fence-post warning
4511 When attempting to run even a simple program, a warning about
4512 heuristic-fence-post being hit would be reported. This problem has
4515 * MIPS IRIX 'long double' crashed GDB
4517 When examining a long double variable, GDB would get a segmentation
4518 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4519 IRIX long double values).
4523 A bug in the VAX stack code was causing problems with the "next"
4524 command. This problem has been fixed.
4526 *** Changes in GDB 6.2:
4528 * Fix for ``many threads''
4530 On GNU/Linux systems that use the NPTL threads library, a program
4531 rapidly creating and deleting threads would confuse GDB leading to the
4534 ptrace: No such process.
4535 thread_db_get_info: cannot get thread info: generic error
4537 This problem has been fixed.
4539 * "-async" and "-noasync" options removed.
4541 Support for the broken "-noasync" option has been removed (it caused
4544 * New ``start'' command.
4546 This command runs the program until the begining of the main procedure.
4548 * New BSD Kernel Data Access Library (libkvm) interface
4550 Using ``target kvm'' it is now possible to debug kernel core dumps and
4551 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4552 platforms. Currently supported (native-only) configurations are:
4554 FreeBSD/amd64 x86_64-*-freebsd*
4555 FreeBSD/i386 i?86-*-freebsd*
4556 NetBSD/i386 i?86-*-netbsd*
4557 NetBSD/m68k m68*-*-netbsd*
4558 NetBSD/sparc sparc-*-netbsd*
4559 OpenBSD/amd64 x86_64-*-openbsd*
4560 OpenBSD/i386 i?86-*-openbsd*
4561 OpenBSD/m68k m68*-openbsd*
4562 OpenBSD/sparc sparc-*-openbsd*
4564 * Signal trampoline code overhauled
4566 Many generic problems with GDB's signal handling code have been fixed.
4567 These include: backtraces through non-contiguous stacks; recognition
4568 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4569 call; backtrace through a signal trampoline; step into and out of
4570 signal handlers; and single-stepping in the signal trampoline.
4572 Please note that kernel bugs are a limiting factor here. These
4573 features have been shown to work on an s390 GNU/Linux system that
4574 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4576 * Cygwin support for DWARF 2 added.
4578 * New native configurations
4580 GNU/Linux/hppa hppa*-*-linux*
4581 OpenBSD/hppa hppa*-*-openbsd*
4582 OpenBSD/m68k m68*-*-openbsd*
4583 OpenBSD/m88k m88*-*-openbsd*
4584 OpenBSD/powerpc powerpc-*-openbsd*
4585 NetBSD/vax vax-*-netbsd*
4586 OpenBSD/vax vax-*-openbsd*
4588 * END-OF-LIFE frame compatibility module
4590 GDB's internal frame infrastructure has been completely rewritten.
4591 The new infrastructure making it possible to support key new features
4592 including DWARF 2 Call Frame Information. To aid in the task of
4593 migrating old configurations to this new infrastructure, a
4594 compatibility module, that allowed old configurations to continue to
4595 work, was also included.
4597 GDB 6.2 will be the last release to include this frame compatibility
4598 module. This change directly impacts the following configurations:
4608 Unless there is activity to revive these configurations, they will be
4609 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4611 * REMOVED configurations and files
4613 Sun 3, running SunOS 3 m68*-*-sunos3*
4614 Sun 3, running SunOS 4 m68*-*-sunos4*
4615 Sun 2, running SunOS 3 m68000-*-sunos3*
4616 Sun 2, running SunOS 4 m68000-*-sunos4*
4617 Motorola 680x0 running LynxOS m68*-*-lynxos*
4618 AT&T 3b1/Unix pc m68*-att-*
4619 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4620 decstation mips-dec-* mips-little-*
4621 riscos mips-*-riscos* mips-*-sysv*
4622 sonymips mips-sony-*
4623 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4625 *** Changes in GDB 6.1.1:
4627 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4629 The TUI (Text-mode User Interface) is now built as part of a default
4630 GDB configuration. It is enabled by either selecting the TUI with the
4631 command line option "-i=tui" or by running the separate "gdbtui"
4632 program. For more information on the TUI, see the manual "Debugging
4635 * Pending breakpoint support (also included in GDB 6.1)
4637 Support has been added to allow you to specify breakpoints in shared
4638 libraries that have not yet been loaded. If a breakpoint location
4639 cannot be found, and the "breakpoint pending" option is set to auto,
4640 GDB queries you if you wish to make the breakpoint pending on a future
4641 shared-library load. If and when GDB resolves the breakpoint symbol,
4642 the pending breakpoint is removed as one or more regular breakpoints
4645 Pending breakpoints are very useful for GCJ Java debugging.
4647 * Fixed ISO-C build problems
4649 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4650 non ISO-C code that stopped them being built using a more strict ISO-C
4651 compiler (e.g., IBM's C compiler).
4653 * Fixed build problem on IRIX 5
4655 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4656 wasn't able to compile compile on an IRIX 5 system.
4658 * Added execute permission to gdb/gdbserver/configure
4660 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4661 permission. This bug would cause configure to fail on a number of
4662 systems (Solaris, IRIX). Ref: server/519.
4664 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4666 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4667 has been updated to use constant array sizes.
4669 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4671 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4672 its generated DWARF Call Frame Info. This encoding was causing GDB to
4673 panic, that panic has been fixed. Ref: gdb/1628.
4675 * Fixed a problem when examining parameters in shared library code.
4677 When examining parameters in optimized shared library code generated
4678 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4679 not available''. GDB now correctly displays the variable's value.
4681 *** Changes in GDB 6.1:
4683 * Removed --with-mmalloc
4685 Support for the mmalloc memory manager has been removed, as it
4686 conflicted with the internal gdb byte cache.
4688 * Changes in AMD64 configurations
4690 The AMD64 target now includes the %cs and %ss registers. As a result
4691 the AMD64 remote protocol has changed; this affects the floating-point
4692 and SSE registers. If you rely on those registers for your debugging,
4693 you should upgrade gdbserver on the remote side.
4695 * Revised SPARC target
4697 The SPARC target has been completely revised, incorporating the
4698 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4699 support for LynxOS and SunOS 4 has been dropped. Calling functions
4700 from within GDB on operating systems with a non-executable stack
4701 (Solaris, OpenBSD) now works.
4705 GDB has a new C++ demangler which does a better job on the mangled
4706 names generated by current versions of g++. It also runs faster, so
4707 with this and other changes gdb should now start faster on large C++
4710 * DWARF 2 Location Expressions
4712 GDB support for location expressions has been extended to support function
4713 arguments and frame bases. Older versions of GDB could crash when they
4716 * C++ nested types and namespaces
4718 GDB's support for nested types and namespaces in C++ has been
4719 improved, especially if you use the DWARF 2 debugging format. (This
4720 is the default for recent versions of GCC on most platforms.)
4721 Specifically, if you have a class "Inner" defined within a class or
4722 namespace "Outer", then GDB realizes that the class's name is
4723 "Outer::Inner", not simply "Inner". This should greatly reduce the
4724 frequency of complaints about not finding RTTI symbols. In addition,
4725 if you are stopped at inside of a function defined within a namespace,
4726 GDB modifies its name lookup accordingly.
4728 * New native configurations
4730 NetBSD/amd64 x86_64-*-netbsd*
4731 OpenBSD/amd64 x86_64-*-openbsd*
4732 OpenBSD/alpha alpha*-*-openbsd*
4733 OpenBSD/sparc sparc-*-openbsd*
4734 OpenBSD/sparc64 sparc64-*-openbsd*
4736 * New debugging protocols
4738 M32R with SDI protocol m32r-*-elf*
4740 * "set prompt-escape-char" command deleted.
4742 The command "set prompt-escape-char" has been deleted. This command,
4743 and its very obscure effet on GDB's prompt, was never documented,
4744 tested, nor mentioned in the NEWS file.
4746 * OBSOLETE configurations and files
4748 Configurations that have been declared obsolete in this release have
4749 been commented out. Unless there is activity to revive these
4750 configurations, the next release of GDB will have their sources
4751 permanently REMOVED.
4753 Sun 3, running SunOS 3 m68*-*-sunos3*
4754 Sun 3, running SunOS 4 m68*-*-sunos4*
4755 Sun 2, running SunOS 3 m68000-*-sunos3*
4756 Sun 2, running SunOS 4 m68000-*-sunos4*
4757 Motorola 680x0 running LynxOS m68*-*-lynxos*
4758 AT&T 3b1/Unix pc m68*-att-*
4759 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4760 decstation mips-dec-* mips-little-*
4761 riscos mips-*-riscos* mips-*-sysv*
4762 sonymips mips-sony-*
4763 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4765 * REMOVED configurations and files
4767 SGI Irix-4.x mips-sgi-irix4 or iris4
4768 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4769 Z8000 simulator z8k-zilog-none or z8ksim
4770 Matsushita MN10200 w/simulator mn10200-*-*
4771 H8/500 simulator h8500-hitachi-hms or h8500hms
4772 HP/PA running BSD hppa*-*-bsd*
4773 HP/PA running OSF/1 hppa*-*-osf*
4774 HP/PA Pro target hppa*-*-pro*
4775 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4776 386BSD i[3456]86-*-bsd*
4777 Sequent family i[3456]86-sequent-sysv4*
4778 i[3456]86-sequent-sysv*
4779 i[3456]86-sequent-bsd*
4780 SPARC running LynxOS sparc-*-lynxos*
4781 SPARC running SunOS 4 sparc-*-sunos4*
4782 Tsqware Sparclet sparclet-*-*
4783 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4785 *** Changes in GDB 6.0:
4789 Support for debugging the Objective-C programming language has been
4790 integrated into GDB.
4792 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4794 DWARF 2's Call Frame Information makes available compiler generated
4795 information that more exactly describes the program's run-time stack.
4796 By using this information, GDB is able to provide more robust stack
4799 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4800 have been updated to use a new backtrace mechanism which includes
4801 DWARF 2 CFI support.
4805 GDB's remote protocol has been extended to include support for hosted
4806 file I/O (where the remote target uses GDB's file system). See GDB's
4807 remote protocol documentation for details.
4809 * All targets using the new architecture framework.
4811 All of GDB's targets have been updated to use the new internal
4812 architecture framework. The way is now open for future GDB releases
4813 to include cross-architecture native debugging support (i386 on amd64,
4816 * GNU/Linux's Thread Local Storage (TLS)
4818 GDB now includes support for for the GNU/Linux implementation of
4819 per-thread variables.
4821 * GNU/Linux's Native POSIX Thread Library (NPTL)
4823 GDB's thread code has been updated to work with either the new
4824 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4826 * Separate debug info.
4828 GDB, in conjunction with BINUTILS, now supports a mechanism for
4829 automatically loading debug information from a separate file. Instead
4830 of shipping full debug and non-debug versions of system libraries,
4831 system integrators can now instead ship just the stripped libraries
4832 and optional debug files.
4834 * DWARF 2 Location Expressions
4836 DWARF 2 Location Expressions allow the compiler to more completely
4837 describe the location of variables (even in optimized code) to the
4840 GDB now includes preliminary support for location expressions (support
4841 for DW_OP_piece is still missing).
4845 A number of long standing bugs that caused GDB to die while starting a
4846 Java application have been fixed. GDB's Java support is now
4847 considered "useable".
4849 * GNU/Linux support for fork, vfork, and exec.
4851 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4852 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4855 * GDB supports logging output to a file
4857 There are two new commands, "set logging" and "show logging", which can be
4858 used to capture GDB's output to a file.
4860 * The meaning of "detach" has changed for gdbserver
4862 The "detach" command will now resume the application, as documented. To
4863 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4866 * d10v, m68hc11 `regs' command deprecated
4868 The `info registers' command has been updated so that it displays the
4869 registers using a format identical to the old `regs' command.
4873 A new command, "maint set profile on/off", has been added. This command can
4874 be used to enable or disable profiling while running GDB, to profile a
4875 session or a set of commands. In addition there is a new configure switch,
4876 "--enable-profiling", which will cause GDB to be compiled with profiling
4877 data, for more informative profiling results.
4879 * Default MI syntax changed to "mi2".
4881 The default MI (machine interface) syntax, enabled by the command line
4882 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4883 "mi1", can be enabled by specifying the option "-i=mi1".
4885 Support for the original "mi0" syntax (included in GDB 5.0) has been
4888 Fix for gdb/192: removed extraneous space when displaying frame level.
4889 Fix for gdb/672: update changelist is now output in mi list format.
4890 Fix for gdb/702: a -var-assign that updates the value now shows up
4891 in a subsequent -var-update.
4893 * New native configurations.
4895 FreeBSD/amd64 x86_64-*-freebsd*
4897 * Multi-arched targets.
4899 HP/PA HPUX11 hppa*-*-hpux*
4900 Renesas M32R/D w/simulator m32r-*-elf*
4902 * OBSOLETE configurations and files
4904 Configurations that have been declared obsolete in this release have
4905 been commented out. Unless there is activity to revive these
4906 configurations, the next release of GDB will have their sources
4907 permanently REMOVED.
4909 Z8000 simulator z8k-zilog-none or z8ksim
4910 Matsushita MN10200 w/simulator mn10200-*-*
4911 H8/500 simulator h8500-hitachi-hms or h8500hms
4912 HP/PA running BSD hppa*-*-bsd*
4913 HP/PA running OSF/1 hppa*-*-osf*
4914 HP/PA Pro target hppa*-*-pro*
4915 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4916 Sequent family i[3456]86-sequent-sysv4*
4917 i[3456]86-sequent-sysv*
4918 i[3456]86-sequent-bsd*
4919 Tsqware Sparclet sparclet-*-*
4920 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4922 * REMOVED configurations and files
4925 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4926 IBM AIX PS/2 i[3456]86-*-aix
4927 i386 running Mach 3.0 i[3456]86-*-mach3*
4928 i386 running Mach i[3456]86-*-mach*
4929 i386 running OSF/1 i[3456]86-*osf1mk*
4930 HP/Apollo 68k Family m68*-apollo*-sysv*,
4932 m68*-hp-bsd*, m68*-hp-hpux*
4933 Argonaut Risc Chip (ARC) arc-*-*
4934 Mitsubishi D30V d30v-*-*
4935 Fujitsu FR30 fr30-*-elf*
4936 OS/9000 i[34]86-*-os9k
4937 I960 with MON960 i960-*-coff
4939 * MIPS $fp behavior changed
4941 The convenience variable $fp, for the MIPS, now consistently returns
4942 the address of the current frame's base. Previously, depending on the
4943 context, $fp could refer to either $sp or the current frame's base
4944 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4945 The GNU Source-Level Debugger''.
4947 *** Changes in GDB 5.3:
4949 * GNU/Linux shared library multi-threaded performance improved.
4951 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4952 `/proc', in preference to `ptrace' for memory reads. This may result
4953 in an improvement in the start-up time of multi-threaded, shared
4954 library applications when run under GDB. One GDB user writes: ``loads
4955 shared libs like mad''.
4957 * ``gdbserver'' now supports multi-threaded applications on some targets
4959 Support for debugging multi-threaded applications which use
4960 the GNU/Linux LinuxThreads package has been added for
4961 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4962 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4964 * GDB now supports C/C++ preprocessor macros.
4966 GDB now expands preprocessor macro invocations in C/C++ expressions,
4967 and provides various commands for showing macro definitions and how
4970 The new command `macro expand EXPRESSION' expands any macro
4971 invocations in expression, and shows the result.
4973 The new command `show macro MACRO-NAME' shows the definition of the
4974 macro named MACRO-NAME, and where it was defined.
4976 Most compilers don't include information about macros in the debugging
4977 information by default. In GCC 3.1, for example, you need to compile
4978 your program with the options `-gdwarf-2 -g3'. If the macro
4979 information is present in the executable, GDB will read it.
4981 * Multi-arched targets.
4983 DEC Alpha (partial) alpha*-*-*
4984 DEC VAX (partial) vax-*-*
4986 National Semiconductor NS32000 (partial) ns32k-*-*
4987 Motorola 68000 (partial) m68k-*-*
4988 Motorola MCORE mcore-*-*
4992 Fujitsu FRV architecture added by Red Hat frv*-*-*
4995 * New native configurations
4997 Alpha NetBSD alpha*-*-netbsd*
4998 SH NetBSD sh*-*-netbsdelf*
4999 MIPS NetBSD mips*-*-netbsd*
5000 UltraSPARC NetBSD sparc64-*-netbsd*
5002 * OBSOLETE configurations and files
5004 Configurations that have been declared obsolete in this release have
5005 been commented out. Unless there is activity to revive these
5006 configurations, the next release of GDB will have their sources
5007 permanently REMOVED.
5009 Mitsubishi D30V d30v-*-*
5010 OS/9000 i[34]86-*-os9k
5011 IBM AIX PS/2 i[3456]86-*-aix
5012 Fujitsu FR30 fr30-*-elf*
5013 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5014 Argonaut Risc Chip (ARC) arc-*-*
5015 i386 running Mach 3.0 i[3456]86-*-mach3*
5016 i386 running Mach i[3456]86-*-mach*
5017 i386 running OSF/1 i[3456]86-*osf1mk*
5018 HP/Apollo 68k Family m68*-apollo*-sysv*,
5020 m68*-hp-bsd*, m68*-hp-hpux*
5021 I960 with MON960 i960-*-coff
5023 * OBSOLETE languages
5025 CHILL, a Pascal like language used by telecommunications companies.
5027 * REMOVED configurations and files
5029 AMD 29k family via UDI a29k-amd-udi, udi29k
5030 A29K VxWorks a29k-*-vxworks
5031 AMD 29000 embedded, using EBMON a29k-none-none
5032 AMD 29000 embedded with COFF a29k-none-coff
5033 AMD 29000 embedded with a.out a29k-none-aout
5035 testsuite/gdb.hp/gdb.threads-hp/ directory
5037 * New command "set max-user-call-depth <nnn>"
5039 This command allows the user to limit the call depth of user-defined
5040 commands. The default is 1024.
5042 * Changes in FreeBSD/i386 native debugging.
5044 Support for the "generate-core-file" has been added.
5046 * New commands "dump", "append", and "restore".
5048 These commands allow data to be copied from target memory
5049 to a bfd-format or binary file (dump and append), and back
5050 from a file into memory (restore).
5052 * Improved "next/step" support on multi-processor Alpha Tru64.
5054 The previous single-step mechanism could cause unpredictable problems,
5055 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5056 of a software single-step mechanism prevents this.
5058 *** Changes in GDB 5.2.1:
5066 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5067 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5068 Fix, by Joel Brobecker imported from mainline.
5070 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5071 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5072 Fix, by Fred Fish, imported from mainline.
5074 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5075 Surprisingly enough, it works now.
5076 By Michal Ludvig, imported from mainline.
5078 i386 hardware watchpoint support:
5079 avoid misses on second run for some targets.
5080 By Pierre Muller, imported from mainline.
5082 *** Changes in GDB 5.2:
5084 * New command "set trust-readonly-sections on[off]".
5086 This command is a hint that tells gdb that read-only sections
5087 really are read-only (ie. that their contents will not change).
5088 In this mode, gdb will go to the object file rather than the
5089 target to read memory from read-only sections (such as ".text").
5090 This can be a significant performance improvement on some
5091 (notably embedded) targets.
5093 * New command "generate-core-file" (or "gcore").
5095 This new gdb command allows the user to drop a core file of the child
5096 process state at any time. So far it's been implemented only for
5097 GNU/Linux and Solaris, but should be relatively easily ported to other
5098 hosts. Argument is core file name (defaults to core.<pid>).
5100 * New command line option
5102 GDB now accepts --pid or -p followed by a process id.
5104 * Change in command line behavior -- corefiles vs. process ids.
5106 There is a subtle behavior in the way in which GDB handles
5107 command line arguments. The first non-flag argument is always
5108 a program to debug, but the second non-flag argument may either
5109 be a corefile or a process id. Previously, GDB would attempt to
5110 open the second argument as a corefile, and if that failed, would
5111 issue a superfluous error message and then attempt to attach it as
5112 a process. Now, if the second argument begins with a non-digit,
5113 it will be treated as a corefile. If it begins with a digit,
5114 GDB will attempt to attach it as a process, and if no such process
5115 is found, will then attempt to open it as a corefile.
5117 * Changes in ARM configurations.
5119 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5120 configuration is fully multi-arch.
5122 * New native configurations
5124 ARM NetBSD arm*-*-netbsd*
5125 x86 OpenBSD i[3456]86-*-openbsd*
5126 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5127 Sparc64 running FreeBSD sparc64-*-freebsd*
5131 Sanyo XStormy16 xstormy16-elf
5133 * OBSOLETE configurations and files
5135 Configurations that have been declared obsolete in this release have
5136 been commented out. Unless there is activity to revive these
5137 configurations, the next release of GDB will have their sources
5138 permanently REMOVED.
5140 AMD 29k family via UDI a29k-amd-udi, udi29k
5141 A29K VxWorks a29k-*-vxworks
5142 AMD 29000 embedded, using EBMON a29k-none-none
5143 AMD 29000 embedded with COFF a29k-none-coff
5144 AMD 29000 embedded with a.out a29k-none-aout
5146 testsuite/gdb.hp/gdb.threads-hp/ directory
5148 * REMOVED configurations and files
5150 TI TMS320C80 tic80-*-*
5152 PowerPC Solaris powerpcle-*-solaris*
5153 PowerPC Windows NT powerpcle-*-cygwin32
5154 PowerPC Netware powerpc-*-netware*
5155 Harris/CXUX m88k m88*-harris-cxux*
5156 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5157 ns32k-utek-sysv* ns32k-utek-*
5158 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5159 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5160 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5161 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5162 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5164 * Changes to command line processing
5166 The new `--args' feature can be used to specify command-line arguments
5167 for the inferior from gdb's command line.
5169 * Changes to key bindings
5171 There is a new `operate-and-get-next' function bound to `C-o'.
5173 *** Changes in GDB 5.1.1
5175 Fix compile problem on DJGPP.
5177 Fix a problem with floating-point registers on the i386 being
5180 Fix to stop GDB crashing on .debug_str debug info.
5182 Numerous documentation fixes.
5184 Numerous testsuite fixes.
5186 *** Changes in GDB 5.1:
5188 * New native configurations
5190 Alpha FreeBSD alpha*-*-freebsd*
5191 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5192 MIPS GNU/Linux mips*-*-linux*
5193 MIPS SGI Irix 6.x mips*-sgi-irix6*
5194 ia64 AIX ia64-*-aix*
5195 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5199 Motorola 68HC11 and 68HC12 m68hc11-elf
5201 UltraSparc running GNU/Linux sparc64-*-linux*
5203 * OBSOLETE configurations and files
5205 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5206 Harris/CXUX m88k m88*-harris-cxux*
5207 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5208 ns32k-utek-sysv* ns32k-utek-*
5209 TI TMS320C80 tic80-*-*
5211 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5212 PowerPC Solaris powerpcle-*-solaris*
5213 PowerPC Windows NT powerpcle-*-cygwin32
5214 PowerPC Netware powerpc-*-netware*
5215 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5216 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5217 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5218 Apple Macintosh (MPW) host N/A
5220 stuff.c (Program to stuff files into a specially prepared space in kdb)
5221 kdb-start.c (Main loop for the standalone kernel debugger)
5223 Configurations that have been declared obsolete in this release have
5224 been commented out. Unless there is activity to revive these
5225 configurations, the next release of GDB will have their sources
5226 permanently REMOVED.
5228 * REMOVED configurations and files
5230 Altos 3068 m68*-altos-*
5231 Convex c1-*-*, c2-*-*
5233 ARM RISCix arm-*-* (as host)
5237 * GDB has been converted to ISO C.
5239 GDB's source code has been converted to ISO C. In particular, the
5240 sources are fully protoized, and rely on standard headers being
5245 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5247 * The MI enabled by default.
5249 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5250 revised and enabled by default. Packages which use GDB as a debugging
5251 engine behind a UI or another front end are encouraged to switch to
5252 using the GDB/MI interface, instead of the old annotations interface
5253 which is now deprecated.
5255 * Support for debugging Pascal programs.
5257 GDB now includes support for debugging Pascal programs. The following
5258 main features are supported:
5260 - Pascal-specific data types such as sets;
5262 - automatic recognition of Pascal sources based on file-name
5265 - Pascal-style display of data types, variables, and functions;
5267 - a Pascal expression parser.
5269 However, some important features are not yet supported.
5271 - Pascal string operations are not supported at all;
5273 - there are some problems with boolean types;
5275 - Pascal type hexadecimal constants are not supported
5276 because they conflict with the internal variables format;
5278 - support for Pascal objects and classes is not full yet;
5280 - unlike Pascal, GDB is case-sensitive for symbol names.
5282 * Changes in completion.
5284 Commands such as `shell', `run' and `set args', which pass arguments
5285 to inferior programs, now complete on file names, similar to what
5286 users expect at the shell prompt.
5288 Commands which accept locations, such as `disassemble', `print',
5289 `breakpoint', `until', etc. now complete on filenames as well as
5290 program symbols. Thus, if you type "break foob TAB", and the source
5291 files linked into the programs include `foobar.c', that file name will
5292 be one of the candidates for completion. However, file names are not
5293 considered for completion after you typed a colon that delimits a file
5294 name from a name of a function in that file, as in "break foo.c:bar".
5296 `set demangle-style' completes on available demangling styles.
5298 * New platform-independent commands:
5300 It is now possible to define a post-hook for a command as well as a
5301 hook that runs before the command. For more details, see the
5302 documentation of `hookpost' in the GDB manual.
5304 * Changes in GNU/Linux native debugging.
5306 Support for debugging multi-threaded programs has been completely
5307 revised for all platforms except m68k and sparc. You can now debug as
5308 many threads as your system allows you to have.
5310 Attach/detach is supported for multi-threaded programs.
5312 Support for SSE registers was added for x86. This doesn't work for
5313 multi-threaded programs though.
5315 * Changes in MIPS configurations.
5317 Multi-arch support is enabled for all MIPS configurations.
5319 GDB can now be built as native debugger on SGI Irix 6.x systems for
5320 debugging n32 executables. (Debugging 64-bit executables is not yet
5323 * Unified support for hardware watchpoints in all x86 configurations.
5325 Most (if not all) native x86 configurations support hardware-assisted
5326 breakpoints and watchpoints in a unified manner. This support
5327 implements debug register sharing between watchpoints, which allows to
5328 put a virtually infinite number of watchpoints on the same address,
5329 and also supports watching regions up to 16 bytes with several debug
5332 The new maintenance command `maintenance show-debug-regs' toggles
5333 debugging print-outs in functions that insert, remove, and test
5334 watchpoints and hardware breakpoints.
5336 * Changes in the DJGPP native configuration.
5338 New command ``info dos sysinfo'' displays assorted information about
5339 the CPU, OS, memory, and DPMI server.
5341 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5342 display information about segment descriptors stored in GDT, LDT, and
5345 New commands ``info dos pde'' and ``info dos pte'' display entries
5346 from Page Directory and Page Tables (for now works with CWSDPMI only).
5347 New command ``info dos address-pte'' displays the Page Table entry for
5348 a given linear address.
5350 GDB can now pass command lines longer than 126 characters to the
5351 program being debugged (requires an update to the libdbg.a library
5352 which is part of the DJGPP development kit).
5354 DWARF2 debug info is now supported.
5356 It is now possible to `step' and `next' through calls to `longjmp'.
5358 * Changes in documentation.
5360 All GDB documentation was converted to GFDL, the GNU Free
5361 Documentation License.
5363 Tracepoints-related commands are now fully documented in the GDB
5366 TUI, the Text-mode User Interface, is now documented in the manual.
5368 Tracepoints-related commands are now fully documented in the GDB
5371 The "GDB Internals" manual now has an index. It also includes
5372 documentation of `ui_out' functions, GDB coding standards, x86
5373 hardware watchpoints, and memory region attributes.
5375 * GDB's version number moved to ``version.in''
5377 The Makefile variable VERSION has been replaced by the file
5378 ``version.in''. People creating GDB distributions should update the
5379 contents of this file.
5383 GUD support is now a standard part of the EMACS distribution.
5385 *** Changes in GDB 5.0:
5387 * Improved support for debugging FP programs on x86 targets
5389 Unified and much-improved support for debugging floating-point
5390 programs on all x86 targets. In particular, ``info float'' now
5391 displays the FP registers in the same format on all x86 targets, with
5392 greater level of detail.
5394 * Improvements and bugfixes in hardware-assisted watchpoints
5396 It is now possible to watch array elements, struct members, and
5397 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5398 on x86 targets no longer erroneously trigger when the address is
5401 * Improvements in the native DJGPP version of GDB
5403 The distribution now includes all the scripts and auxiliary files
5404 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5405 machines ``out of the box''.
5407 The DJGPP version can now debug programs that use signals. It is
5408 possible to catch signals that happened in the debuggee, deliver
5409 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5410 would kill the program being debugged.) Programs that hook hardware
5411 interrupts (keyboard, timer, etc.) can also be debugged.
5413 It is now possible to debug DJGPP programs that redirect their
5414 standard handles or switch them to raw (as opposed to cooked) mode, or
5415 even close them. The command ``run < foo > bar'' works as expected,
5416 and ``info terminal'' reports useful information about the debuggee's
5417 terminal, including raw/cooked mode, redirection, etc.
5419 The DJGPP version now uses termios functions for console I/O, which
5420 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5423 DOS-style file names with drive letters are now fully supported by
5426 It is now possible to debug DJGPP programs that switch their working
5427 directory. It is also possible to rerun the debuggee any number of
5428 times without restarting GDB; thus, you can use the same setup,
5429 breakpoints, etc. for many debugging sessions.
5431 * New native configurations
5433 ARM GNU/Linux arm*-*-linux*
5434 PowerPC GNU/Linux powerpc-*-linux*
5438 Motorola MCore mcore-*-*
5439 x86 VxWorks i[3456]86-*-vxworks*
5440 PowerPC VxWorks powerpc-*-vxworks*
5441 TI TMS320C80 tic80-*-*
5443 * OBSOLETE configurations
5445 Altos 3068 m68*-altos-*
5446 Convex c1-*-*, c2-*-*
5448 ARM RISCix arm-*-* (as host)
5451 Configurations that have been declared obsolete will be commented out,
5452 but the code will be left in place. If there is no activity to revive
5453 these configurations before the next release of GDB, the sources will
5454 be permanently REMOVED.
5456 * Gould support removed
5458 Support for the Gould PowerNode and NP1 has been removed.
5460 * New features for SVR4
5462 On SVR4 native platforms (such as Solaris), if you attach to a process
5463 without first loading a symbol file, GDB will now attempt to locate and
5464 load symbols from the running process's executable file.
5466 * Many C++ enhancements
5468 C++ support has been greatly improved. Overload resolution now works properly
5469 in almost all cases. RTTI support is on the way.
5471 * Remote targets can connect to a sub-program
5473 A popen(3) style serial-device has been added. This device starts a
5474 sub-process (such as a stand-alone simulator) and then communicates
5475 with that. The sub-program to run is specified using the syntax
5476 ``|<program> <args>'' vis:
5478 (gdb) set remotedebug 1
5479 (gdb) target extended-remote |mn10300-elf-sim program-args
5481 * MIPS 64 remote protocol
5483 A long standing bug in the mips64 remote protocol where by GDB
5484 expected certain 32 bit registers (ex SR) to be transfered as 32
5485 instead of 64 bits has been fixed.
5487 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5488 added to provide backward compatibility with older versions of GDB.
5490 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5492 The command ``set remotebinarydownload'' command has been replaced by
5493 ``set remote X-packet''. Other commands in ``set remote'' family
5494 include ``set remote P-packet''.
5496 * Breakpoint commands accept ranges.
5498 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5499 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5500 ``tracepoint passcount'' also accepts a range of tracepoints.
5502 * ``apropos'' command added.
5504 The ``apropos'' command searches through command names and
5505 documentation strings, printing out matches, making it much easier to
5506 try to find a command that does what you are looking for.
5510 A new machine oriented interface (MI) has been added to GDB. This
5511 interface is designed for debug environments running GDB as a separate
5512 process. This is part of the long term libGDB project. See the
5513 "GDB/MI" chapter of the GDB manual for further information. It can be
5514 enabled by configuring with:
5516 .../configure --enable-gdbmi
5518 *** Changes in GDB-4.18:
5520 * New native configurations
5522 HP-UX 10.20 hppa*-*-hpux10.20
5523 HP-UX 11.x hppa*-*-hpux11.0*
5524 M68K GNU/Linux m68*-*-linux*
5528 Fujitsu FR30 fr30-*-elf*
5529 Intel StrongARM strongarm-*-*
5530 Mitsubishi D30V d30v-*-*
5532 * OBSOLETE configurations
5534 Gould PowerNode, NP1 np1-*-*, pn-*-*
5536 Configurations that have been declared obsolete will be commented out,
5537 but the code will be left in place. If there is no activity to revive
5538 these configurations before the next release of GDB, the sources will
5539 be permanently REMOVED.
5543 As a compatibility experiment, GDB's source files buildsym.h and
5544 buildsym.c have been converted to pure standard C, no longer
5545 containing any K&R compatibility code. We believe that all systems in
5546 use today either come with a standard C compiler, or have a GCC port
5547 available. If this is not true, please report the affected
5548 configuration to bug-gdb@gnu.org immediately. See the README file for
5549 information about getting a standard C compiler if you don't have one
5554 GDB now uses readline 2.2.
5556 * set extension-language
5558 You can now control the mapping between filename extensions and source
5559 languages by using the `set extension-language' command. For instance,
5560 you can ask GDB to treat .c files as C++ by saying
5561 set extension-language .c c++
5562 The command `info extensions' lists all of the recognized extensions
5563 and their associated languages.
5565 * Setting processor type for PowerPC and RS/6000
5567 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5568 you can use the `set processor' command to specify what variant of the
5569 PowerPC family you are debugging. The command
5573 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5574 following PowerPC and RS6000 variants:
5576 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5577 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5579 403GC IBM PowerPC 403GC
5580 505 Motorola PowerPC 505
5581 860 Motorola PowerPC 860 or 850
5582 601 Motorola PowerPC 601
5583 602 Motorola PowerPC 602
5584 603 Motorola/IBM PowerPC 603 or 603e
5585 604 Motorola PowerPC 604 or 604e
5586 750 Motorola/IBM PowerPC 750 or 750
5588 At the moment, this command just tells GDB what to name the
5589 special-purpose processor registers. Since almost all the affected
5590 registers are inaccessible to user-level programs, this command is
5591 only useful for remote debugging in its present form.
5595 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5596 more extensive support for HP-UX. Added features include shared
5597 library support, kernel threads and hardware watchpoints for 11.00,
5598 support for HP's ANSI C and C++ compilers, and a compatibility mode
5599 for xdb and dbx commands.
5603 HP's donation includes the new concept of catchpoints, which is a
5604 generalization of the old catch command. On HP-UX, it is now possible
5605 to catch exec, fork, and vfork, as well as library loading.
5607 This means that the existing catch command has changed; its first
5608 argument now specifies the type of catch to be set up. See the
5609 output of "help catch" for a list of catchpoint types.
5611 * Debugging across forks
5613 On HP-UX, you can choose which process to debug when a fork() happens
5618 HP has donated a curses-based terminal user interface (TUI). To get
5619 it, build with --enable-tui. Although this can be enabled for any
5620 configuration, at present it only works for native HP debugging.
5622 * GDB remote protocol additions
5624 A new protocol packet 'X' that writes binary data is now available.
5625 Default behavior is to try 'X', then drop back to 'M' if the stub
5626 fails to respond. The settable variable `remotebinarydownload'
5627 allows explicit control over the use of 'X'.
5629 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5630 full 64-bit address. The command
5632 set remoteaddresssize 32
5634 can be used to revert to the old behaviour. For existing remote stubs
5635 the change should not be noticed, as the additional address information
5638 In order to assist in debugging stubs, you may use the maintenance
5639 command `packet' to send any text string to the stub. For instance,
5641 maint packet heythere
5643 sends the packet "$heythere#<checksum>". Note that it is very easy to
5644 disrupt a debugging session by sending the wrong packet at the wrong
5647 The compare-sections command allows you to compare section data on the
5648 target to what is in the executable file without uploading or
5649 downloading, by comparing CRC checksums.
5651 * Tracing can collect general expressions
5653 You may now collect general expressions at tracepoints. This requires
5654 further additions to the target-side stub; see tracepoint.c and
5655 doc/agentexpr.texi for further details.
5657 * mask-address variable for Mips
5659 For Mips targets, you may control the zeroing of the upper 32 bits of
5660 a 64-bit address by entering `set mask-address on'. This is mainly
5661 of interest to users of embedded R4xxx and R5xxx processors.
5663 * Higher serial baud rates
5665 GDB's serial code now allows you to specify baud rates 57600, 115200,
5666 230400, and 460800 baud. (Note that your host system may not be able
5667 to achieve all of these rates.)
5671 The i960 configuration now includes an initial implementation of a
5672 builtin simulator, contributed by Jim Wilson.
5675 *** Changes in GDB-4.17:
5677 * New native configurations
5679 Alpha GNU/Linux alpha*-*-linux*
5680 Unixware 2.x i[3456]86-unixware2*
5681 Irix 6.x mips*-sgi-irix6*
5682 PowerPC GNU/Linux powerpc-*-linux*
5683 PowerPC Solaris powerpcle-*-solaris*
5684 Sparc GNU/Linux sparc-*-linux*
5685 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5689 Argonaut Risc Chip (ARC) arc-*-*
5690 Hitachi H8/300S h8300*-*-*
5691 Matsushita MN10200 w/simulator mn10200-*-*
5692 Matsushita MN10300 w/simulator mn10300-*-*
5693 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5694 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5695 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5696 Mitsubishi D10V w/simulator d10v-*-*
5697 Mitsubishi M32R/D w/simulator m32r-*-elf*
5698 Tsqware Sparclet sparclet-*-*
5699 NEC V850 w/simulator v850-*-*
5701 * New debugging protocols
5703 ARM with RDI protocol arm*-*-*
5704 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5705 DDB and LSI variants of PMON protocol mips*-*-*
5706 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5707 PowerPC with SDS protocol powerpc{,le}-*-eabi
5708 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5712 All configurations can now understand and use the DWARF 2 debugging
5713 format. The choice is automatic, if the symbol file contains DWARF 2
5718 GDB now includes basic Java language support. This support is
5719 only useful with Java compilers that produce native machine code.
5721 * solib-absolute-prefix and solib-search-path
5723 For SunOS and SVR4 shared libraries, you may now set the prefix for
5724 loading absolute shared library symbol files, and the search path for
5725 locating non-absolute shared library symbol files.
5727 * Live range splitting
5729 GDB can now effectively debug code for which GCC has performed live
5730 range splitting as part of its optimization. See gdb/doc/LRS for
5731 more details on the expected format of the stabs information.
5735 GDB's support for the GNU Hurd, including thread debugging, has been
5736 updated to work with current versions of the Hurd.
5740 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5741 instruction set. ARM GDB automatically detects when Thumb
5742 instructions are in use, and adjusts disassembly and backtracing
5747 GDB's MIPS target configurations now handle the MIP16 16-bit
5752 GDB now includes support for overlays; if an executable has been
5753 linked such that multiple sections are based at the same address, GDB
5754 will decide which section to use for symbolic info. You can choose to
5755 control the decision manually, using overlay commands, or implement
5756 additional target-side support and use "overlay load-target" to bring
5757 in the overlay mapping. Do "help overlay" for more detail.
5761 The command "info symbol <address>" displays information about
5762 the symbol at the specified address.
5766 The standard remote protocol now includes an extension that allows
5767 asynchronous collection and display of trace data. This requires
5768 extensive support in the target-side debugging stub. Tracing mode
5769 includes a new interaction mode in GDB and new commands: see the
5770 file tracepoint.c for more details.
5774 Configurations for embedded MIPS now include a simulator contributed
5775 by Cygnus Solutions. The simulator supports the instruction sets
5776 of most MIPS variants.
5780 Sparc configurations may now include the ERC32 simulator contributed
5781 by the European Space Agency. The simulator is not built into
5782 Sparc targets by default; configure with --enable-sim to include it.
5786 For target configurations that may include multiple variants of a
5787 basic architecture (such as MIPS and SH), you may now set the
5788 architecture explicitly. "set arch" sets, "info arch" lists
5789 the possible architectures.
5791 *** Changes in GDB-4.16:
5793 * New native configurations
5795 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5796 M68K NetBSD m68k-*-netbsd*
5797 PowerPC AIX 4.x powerpc-*-aix*
5798 PowerPC MacOS powerpc-*-macos*
5799 PowerPC Windows NT powerpcle-*-cygwin32
5800 RS/6000 AIX 4.x rs6000-*-aix4*
5804 ARM with RDP protocol arm-*-*
5805 I960 with MON960 i960-*-coff
5806 MIPS VxWorks mips*-*-vxworks*
5807 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5808 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5810 Matra Sparclet sparclet-*-*
5814 The powerpc-eabi configuration now includes the PSIM simulator,
5815 contributed by Andrew Cagney, with assistance from Mike Meissner.
5816 PSIM is a very elaborate model of the PowerPC, including not only
5817 basic instruction set execution, but also details of execution unit
5818 performance and I/O hardware. See sim/ppc/README for more details.
5822 GDB now works with Solaris 2.5.
5824 * Windows 95/NT native
5826 GDB will now work as a native debugger on Windows 95 and Windows NT.
5827 To build it from source, you must use the "gnu-win32" environment,
5828 which uses a DLL to emulate enough of Unix to run the GNU tools.
5829 Further information, binaries, and sources are available at
5830 ftp.cygnus.com, under pub/gnu-win32.
5832 * dont-repeat command
5834 If a user-defined command includes the command `dont-repeat', then the
5835 command will not be repeated if the user just types return. This is
5836 useful if the command is time-consuming to run, so that accidental
5837 extra keystrokes don't run the same command many times.
5839 * Send break instead of ^C
5841 The standard remote protocol now includes an option to send a break
5842 rather than a ^C to the target in order to interrupt it. By default,
5843 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5845 * Remote protocol timeout
5847 The standard remote protocol includes a new variable `remotetimeout'
5848 that allows you to set the number of seconds before GDB gives up trying
5849 to read from the target. The default value is 2.
5851 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5853 By default GDB will automatically keep track of objects as they are
5854 loaded and unloaded by the dynamic linker. By using the command `set
5855 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5856 when shared library events occur, thus allowing you to set breakpoints
5857 in shared libraries which are explicitly loaded by the inferior.
5859 Note this feature does not work on hpux8. On hpux9 you must link
5860 /usr/lib/end.o into your program. This feature should work
5861 automatically on hpux10.
5863 * Irix 5.x hardware watchpoint support
5865 Irix 5 configurations now support the use of hardware watchpoints.
5867 * Mips protocol "SYN garbage limit"
5869 When debugging a Mips target using the `target mips' protocol, you
5870 may set the number of characters that GDB will ignore by setting
5871 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5872 every character. The default value is 1050.
5874 * Recording and replaying remote debug sessions
5876 If you set `remotelogfile' to the name of a file, gdb will write to it
5877 a recording of a remote debug session. This recording may then be
5878 replayed back to gdb using "gdbreplay". See gdbserver/README for
5879 details. This is useful when you have a problem with GDB while doing
5880 remote debugging; you can make a recording of the session and send it
5881 to someone else, who can then recreate the problem.
5883 * Speedups for remote debugging
5885 GDB includes speedups for downloading and stepping MIPS systems using
5886 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5887 and more efficient S-record downloading.
5889 * Memory use reductions and statistics collection
5891 GDB now uses less memory and reports statistics about memory usage.
5892 Try the `maint print statistics' command, for example.
5894 *** Changes in GDB-4.15:
5896 * Psymtabs for XCOFF
5898 The symbol reader for AIX GDB now uses partial symbol tables. This
5899 can greatly improve startup time, especially for large executables.
5901 * Remote targets use caching
5903 Remote targets now use a data cache to speed up communication with the
5904 remote side. The data cache could lead to incorrect results because
5905 it doesn't know about volatile variables, thus making it impossible to
5906 debug targets which use memory mapped I/O devices. `set remotecache
5907 off' turns the the data cache off.
5909 * Remote targets may have threads
5911 The standard remote protocol now includes support for multiple threads
5912 in the target system, using new protocol commands 'H' and 'T'. See
5913 gdb/remote.c for details.
5917 If GDB is configured with `--enable-netrom', then it will include
5918 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5919 acts as though it is a bank of ROM on the target board, but you can
5920 write into it over the network. GDB's support consists only of
5921 support for fast loading into the emulated ROM; to debug, you must use
5922 another protocol, such as standard remote protocol. The usual
5923 sequence is something like
5925 target nrom <netrom-hostname>
5927 target remote <netrom-hostname>:1235
5931 GDB now includes support for the Apple Macintosh, as a host only. It
5932 may be run as either an MPW tool or as a standalone application, and
5933 it can debug through the serial port. All the usual GDB commands are
5934 available, but to the target command, you must supply "serial" as the
5935 device type instead of "/dev/ttyXX". See mpw-README in the main
5936 directory for more information on how to build. The MPW configuration
5937 scripts */mpw-config.in support only a few targets, and only the
5938 mips-idt-ecoff target has been tested.
5942 GDB configuration now uses autoconf. This is not user-visible,
5943 but does simplify configuration and building.
5947 GDB now supports hpux10.
5949 *** Changes in GDB-4.14:
5951 * New native configurations
5953 x86 FreeBSD i[345]86-*-freebsd
5954 x86 NetBSD i[345]86-*-netbsd
5955 NS32k NetBSD ns32k-*-netbsd
5956 Sparc NetBSD sparc-*-netbsd
5960 A29K VxWorks a29k-*-vxworks
5961 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5962 CPU32 EST-300 emulator m68*-*-est*
5963 PowerPC ELF powerpc-*-elf
5966 * Alpha OSF/1 support for procfs
5968 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5969 possible to attach to running processes. As the mounting of the /proc
5970 filesystem is optional on the Alpha, GDB automatically determines
5971 the availability of /proc during startup. This can lead to problems
5972 if /proc is unmounted after GDB has been started.
5974 * Arguments to user-defined commands
5976 User commands may accept up to 10 arguments separated by whitespace.
5977 Arguments are accessed within the user command via $arg0..$arg9. A
5980 print $arg0 + $arg1 + $arg2
5982 To execute the command use:
5985 Defines the command "adder" which prints the sum of its three arguments.
5986 Note the arguments are text substitutions, so they may reference variables,
5987 use complex expressions, or even perform inferior function calls.
5989 * New `if' and `while' commands
5991 This makes it possible to write more sophisticated user-defined
5992 commands. Both commands take a single argument, which is the
5993 expression to evaluate, and must be followed by the commands to
5994 execute, one per line, if the expression is nonzero, the list being
5995 terminated by the word `end'. The `if' command list may include an
5996 `else' word, which causes the following commands to be executed only
5997 if the expression is zero.
5999 * Fortran source language mode
6001 GDB now includes partial support for Fortran 77. It will recognize
6002 Fortran programs and can evaluate a subset of Fortran expressions, but
6003 variables and functions may not be handled correctly. GDB will work
6004 with G77, but does not yet know much about symbols emitted by other
6007 * Better HPUX support
6009 Most debugging facilities now work on dynamic executables for HPPAs
6010 running hpux9 or later. You can attach to running dynamically linked
6011 processes, but by default the dynamic libraries will be read-only, so
6012 for instance you won't be able to put breakpoints in them. To change
6013 that behavior do the following before running the program:
6019 This will cause the libraries to be mapped private and read-write.
6020 To revert to the normal behavior, do this:
6026 You cannot set breakpoints or examine data in the library until after
6027 the library is loaded if the function/data symbols do not have
6030 GDB can now also read debug symbols produced by the HP C compiler on
6031 HPPAs (sorry, no C++, Fortran or 68k support).
6033 * Target byte order now dynamically selectable
6035 You can choose which byte order to use with a target system, via the
6036 commands "set endian big" and "set endian little", and you can see the
6037 current setting by using "show endian". You can also give the command
6038 "set endian auto", in which case GDB will use the byte order
6039 associated with the executable. Currently, only embedded MIPS
6040 configurations support dynamic selection of target byte order.
6042 * New DOS host serial code
6044 This version uses DPMI interrupts to handle buffered I/O, so you
6045 no longer need to run asynctsr when debugging boards connected to
6048 *** Changes in GDB-4.13:
6050 * New "complete" command
6052 This lists all the possible completions for the rest of the line, if it
6053 were to be given as a command itself. This is intended for use by emacs.
6055 * Trailing space optional in prompt
6057 "set prompt" no longer adds a space for you after the prompt you set. This
6058 allows you to set a prompt which ends in a space or one that does not.
6060 * Breakpoint hit counts
6062 "info break" now displays a count of the number of times the breakpoint
6063 has been hit. This is especially useful in conjunction with "ignore"; you
6064 can ignore a large number of breakpoint hits, look at the breakpoint info
6065 to see how many times the breakpoint was hit, then run again, ignoring one
6066 less than that number, and this will get you quickly to the last hit of
6069 * Ability to stop printing at NULL character
6071 "set print null-stop" will cause GDB to stop printing the characters of
6072 an array when the first NULL is encountered. This is useful when large
6073 arrays actually contain only short strings.
6075 * Shared library breakpoints
6077 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6078 breakpoints in shared libraries before the executable is run.
6080 * Hardware watchpoints
6082 There is a new hardware breakpoint for the watch command for sparclite
6083 targets. See gdb/sparclite/hw_breakpoint.note.
6085 Hardware watchpoints are also now supported under GNU/Linux.
6089 Annotations have been added. These are for use with graphical interfaces,
6090 and are still experimental. Currently only gdba.el uses these.
6092 * Improved Irix 5 support
6094 GDB now works properly with Irix 5.2.
6096 * Improved HPPA support
6098 GDB now works properly with the latest GCC and GAS.
6100 * New native configurations
6102 Sequent PTX4 i[34]86-sequent-ptx4
6103 HPPA running OSF/1 hppa*-*-osf*
6104 Atari TT running SVR4 m68*-*-sysv4*
6105 RS/6000 LynxOS rs6000-*-lynxos*
6109 OS/9000 i[34]86-*-os9k
6110 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6113 * Hitachi SH7000 and E7000-PC ICE support
6115 There is now support for communicating with the Hitachi E7000-PC ICE.
6116 This is available automatically when GDB is configured for the SH.
6120 As usual, a variety of small fixes and improvements, both generic
6121 and configuration-specific. See the ChangeLog for more detail.
6123 *** Changes in GDB-4.12:
6125 * Irix 5 is now supported
6129 GDB-4.12 on the HPPA has a number of changes which make it unable
6130 to debug the output from the currently released versions of GCC and
6131 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6132 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6133 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6136 *** Changes in GDB-4.11:
6138 * User visible changes:
6142 The "set remotedebug" option is now consistent between the mips remote
6143 target, remote targets using the gdb-specific protocol, UDI (AMD's
6144 debug protocol for the 29k) and the 88k bug monitor. It is now an
6145 integer specifying a debug level (normally 0 or 1, but 2 means more
6146 debugging info for the mips target).
6148 * DEC Alpha native support
6150 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6151 debug info, but GDB works fairly well with the DEC compiler and should
6152 work with a future GCC release. See the README file for a few
6153 Alpha-specific notes.
6155 * Preliminary thread implementation
6157 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6159 * LynxOS native and target support for 386
6161 This release has been hosted on LynxOS 2.2, and also can be configured
6162 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6165 * Improvements in C++ mangling/demangling.
6167 This release has much better g++ debugging, specifically in name
6168 mangling/demangling, virtual function calls, print virtual table,
6169 call methods, ...etc.
6171 *** Changes in GDB-4.10:
6173 * User visible changes:
6175 Remote debugging using the GDB-specific (`target remote') protocol now
6176 supports the `load' command. This is only useful if you have some
6177 other way of getting the stub to the target system, and you can put it
6178 somewhere in memory where it won't get clobbered by the download.
6180 Filename completion now works.
6182 When run under emacs mode, the "info line" command now causes the
6183 arrow to point to the line specified. Also, "info line" prints
6184 addresses in symbolic form (as well as hex).
6186 All vxworks based targets now support a user settable option, called
6187 vxworks-timeout. This option represents the number of seconds gdb
6188 should wait for responses to rpc's. You might want to use this if
6189 your vxworks target is, perhaps, a slow software simulator or happens
6190 to be on the far side of a thin network line.
6194 This release contains support for using a DEC alpha as a GDB host for
6195 cross debugging. Native alpha debugging is not supported yet.
6198 *** Changes in GDB-4.9:
6202 This is the first GDB release which is accompanied by a matching testsuite.
6203 The testsuite requires installation of dejagnu, which should be available
6204 via ftp from most sites that carry GNU software.
6208 'Cfront' style demangling has had its name changed to 'ARM' style, to
6209 emphasize that it was written from the specifications in the C++ Annotated
6210 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6211 disclaimers, it still generated too much confusion with users attempting to
6212 use gdb with AT&T cfront.
6216 GDB now uses a standard remote interface to a simulator library.
6217 So far, the library contains simulators for the Zilog Z8001/2, the
6218 Hitachi H8/300, H8/500 and Super-H.
6220 * New targets supported
6222 H8/300 simulator h8300-hitachi-hms or h8300hms
6223 H8/500 simulator h8500-hitachi-hms or h8500hms
6224 SH simulator sh-hitachi-hms or sh
6225 Z8000 simulator z8k-zilog-none or z8ksim
6226 IDT MIPS board over serial line mips-idt-ecoff
6228 Cross-debugging to GO32 targets is supported. It requires a custom
6229 version of the i386-stub.c module which is integrated with the
6230 GO32 memory extender.
6232 * New remote protocols
6234 MIPS remote debugging protocol.
6236 * New source languages supported
6238 This version includes preliminary support for Chill, a Pascal like language
6239 used by telecommunications companies. Chill support is also being integrated
6240 into the GNU compiler, but we don't know when it will be publically available.
6243 *** Changes in GDB-4.8:
6245 * HP Precision Architecture supported
6247 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6248 version of this support was available as a set of patches from the
6249 University of Utah. GDB does not support debugging of programs
6250 compiled with the HP compiler, because HP will not document their file
6251 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6252 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6254 Many problems in the preliminary version have been fixed.
6256 * Faster and better demangling
6258 We have improved template demangling and fixed numerous bugs in the GNU style
6259 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6260 character types (wchar_t) are now supported. Demangling of each symbol is now
6261 only done once, and is cached when the symbol table for a file is read in.
6262 This results in a small increase in memory usage for C programs, a moderate
6263 increase in memory usage for C++ programs, and a fantastic speedup in
6266 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6267 from the specifications in the Annotated Reference Manual, which AT&T's
6268 compiler does not actually implement.
6270 * G++ multiple inheritance compiler problem
6272 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6273 inheritance lattices was reworked to properly discover ambiguities. We
6274 recently found an example which causes this new algorithm to fail in a
6275 very subtle way, producing bad debug information for those classes.
6276 The file 'gcc.patch' (in this directory) can be applied to gcc to
6277 circumvent the problem. A future GCC release will contain a complete
6280 The previous G++ debug info problem (mentioned below for the gdb-4.7
6281 release) is fixed in gcc version 2.3.2.
6283 * Improved configure script
6285 The `configure' script will now attempt to guess your system type if
6286 you don't supply a host system type. The old scheme of supplying a
6287 host system triplet is preferable over using this. All the magic is
6288 done in the new `config.guess' script. Examine it for details.
6290 We have also brought our configure script much more in line with the FSF's
6291 version. It now supports the --with-xxx options. In particular,
6292 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6293 The resulting GDB will not be able to read arbitrary object file formats --
6294 only the format ``expected'' to be used on the configured target system.
6295 We hope to make this the default in a future release.
6297 * Documentation improvements
6299 There's new internal documentation on how to modify GDB, and how to
6300 produce clean changes to the code. We implore people to read it
6301 before submitting changes.
6303 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6304 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6305 `info' files are also provided. To build `info' files from scratch,
6306 you will need the latest `makeinfo' release, which will be available in
6307 a future texinfo-X.Y release.
6309 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6310 We're not sure exactly which versions have this problem, but it has
6311 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6312 or better. If that isn't possible, there is a patch in
6313 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6314 around this problem.
6318 GDB now supports array constants that can be used in expressions typed in by
6319 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6320 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6323 The new directory `gdb/sparclite' contains a program that demonstrates
6324 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6326 * New native hosts supported
6328 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6329 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6331 * New targets supported
6333 AMD 29k family via UDI a29k-amd-udi or udi29k
6335 * New file formats supported
6337 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6338 HPUX core files, and SCO 3.2v2 core files.
6342 Attaching to processes now works again; thanks for the many bug reports.
6344 We have also stomped on a bunch of core dumps caused by
6345 printf_filtered("%s") problems.
6347 We eliminated a copyright problem on the rpc and ptrace header files
6348 for VxWorks, which was discovered at the last minute during the 4.7
6349 release. You should now be able to build a VxWorks GDB.
6351 You can now interrupt gdb while an attached process is running. This
6352 will cause the attached process to stop, and give control back to GDB.
6354 We fixed problems caused by using too many file descriptors
6355 for reading symbols from object files and libraries. This was
6356 especially a problem for programs that used many (~100) shared
6359 The `step' command now only enters a subroutine if there is line number
6360 information for the subroutine. Otherwise it acts like the `next'
6361 command. Previously, `step' would enter subroutines if there was
6362 any debugging information about the routine. This avoids problems
6363 when using `cc -g1' on MIPS machines.
6365 * Internal improvements
6367 GDB's internal interfaces have been improved to make it easier to support
6368 debugging of multiple languages in the future.
6370 GDB now uses a common structure for symbol information internally.
6371 Minimal symbols (derived from linkage symbols in object files), partial
6372 symbols (from a quick scan of debug information), and full symbols
6373 contain a common subset of information, making it easier to write
6374 shared code that handles any of them.
6376 * New command line options
6378 We now accept --silent as an alias for --quiet.
6382 The memory-mapped-malloc library is now licensed under the GNU Library
6383 General Public License.
6385 *** Changes in GDB-4.7:
6387 * Host/native/target split
6389 GDB has had some major internal surgery to untangle the support for
6390 hosts and remote targets. Now, when you configure GDB for a remote
6391 target, it will no longer load in all of the support for debugging
6392 local programs on the host. When fully completed and tested, this will
6393 ensure that arbitrary host/target combinations are possible.
6395 The primary conceptual shift is to separate the non-portable code in
6396 GDB into three categories. Host specific code is required any time GDB
6397 is compiled on that host, regardless of the target. Target specific
6398 code relates to the peculiarities of the target, but can be compiled on
6399 any host. Native specific code is everything else: it can only be
6400 built when the host and target are the same system. Child process
6401 handling and core file support are two common `native' examples.
6403 GDB's use of /proc for controlling Unix child processes is now cleaner.
6404 It has been split out into a single module under the `target_ops' vector,
6405 plus two native-dependent functions for each system that uses /proc.
6407 * New hosts supported
6409 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6410 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6411 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6413 * New targets supported
6415 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6416 68030 and CPU32 m68030-*-*, m68332-*-*
6418 * New native hosts supported
6420 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6421 (386bsd is not well tested yet)
6422 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6424 * New file formats supported
6426 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6427 supports reading of `a.out.adobe' object files, which are an a.out
6428 format extended with minimal information about multiple sections.
6432 `show copying' is the same as the old `info copying'.
6433 `show warranty' is the same as `info warrantee'.
6434 These were renamed for consistency. The old commands continue to work.
6436 `info handle' is a new alias for `info signals'.
6438 You can now define pre-command hooks, which attach arbitrary command
6439 scripts to any command. The commands in the hook will be executed
6440 prior to the user's command. You can also create a hook which will be
6441 executed whenever the program stops. See gdb.texinfo.
6445 We now deal with Cfront style name mangling, and can even extract type
6446 info from mangled symbols. GDB can automatically figure out which
6447 symbol mangling style your C++ compiler uses.
6449 Calling of methods and virtual functions has been improved as well.
6453 The crash that occured when debugging Sun Ansi-C compiled binaries is
6454 fixed. This was due to mishandling of the extra N_SO stabs output
6457 We also finally got Ultrix 4.2 running in house, and fixed core file
6458 support, with help from a dozen people on the net.
6460 John M. Farrell discovered that the reason that single-stepping was so
6461 slow on all of the Mips based platforms (primarily SGI and DEC) was
6462 that we were trying to demangle and lookup a symbol used for internal
6463 purposes on every instruction that was being stepped through. Changing
6464 the name of that symbol so that it couldn't be mistaken for a C++
6465 mangled symbol sped things up a great deal.
6467 Rich Pixley sped up symbol lookups in general by getting much smarter
6468 about when C++ symbol mangling is necessary. This should make symbol
6469 completion (TAB on the command line) much faster. It's not as fast as
6470 we'd like, but it's significantly faster than gdb-4.6.
6474 A new user controllable variable 'call_scratch_address' can
6475 specify the location of a scratch area to be used when GDB
6476 calls a function in the target. This is necessary because the
6477 usual method of putting the scratch area on the stack does not work
6478 in systems that have separate instruction and data spaces.
6480 We integrated changes to support the 29k UDI (Universal Debugger
6481 Interface), but discovered at the last minute that we didn't have all
6482 of the appropriate copyright paperwork. We are working with AMD to
6483 resolve this, and hope to have it available soon.
6487 We have sped up the remote serial line protocol, especially for targets
6488 with lots of registers. It now supports a new `expedited status' ('T')
6489 message which can be used in place of the existing 'S' status message.
6490 This allows the remote stub to send only the registers that GDB
6491 needs to make a quick decision about single-stepping or conditional
6492 breakpoints, eliminating the need to fetch the entire register set for
6493 each instruction being stepped through.
6495 The GDB remote serial protocol now implements a write-through cache for
6496 registers, only re-reading the registers if the target has run.
6498 There is also a new remote serial stub for SPARC processors. You can
6499 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6500 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6501 processor with a serial port.
6505 Configure.in files have become much easier to read and modify. A new
6506 `table driven' format makes it more obvious what configurations are
6507 supported, and what files each one uses.
6511 There is a new opcodes library which will eventually contain all of the
6512 disassembly routines and opcode tables. At present, it only contains
6513 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6514 disassembler (binutils/objdump) to share these routines.
6516 The libiberty library is now copylefted under the GNU Library General
6517 Public License. This allows more liberal use, and was done so libg++
6518 can use it. This makes no difference to GDB, since the Library License
6519 grants all the rights from the General Public License.
6523 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6524 reference to the stabs symbol info used by the debugger. It is (as far
6525 as we know) the only published document on this fascinating topic. We
6526 encourage you to read it, compare it to the stabs information on your
6527 system, and send improvements on the document in general (to
6528 bug-gdb@prep.ai.mit.edu).
6530 And, of course, many bugs have been fixed.
6533 *** Changes in GDB-4.6:
6535 * Better support for C++ function names
6537 GDB now accepts as input the "demangled form" of C++ overloaded function
6538 names and member function names, and can do command completion on such names
6539 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6540 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6541 Make use of command completion, it is your friend.
6543 GDB also now accepts a variety of C++ mangled symbol formats. They are
6544 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6545 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6546 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6547 for the list of formats.
6549 * G++ symbol mangling problem
6551 Recent versions of gcc have a bug in how they emit debugging information for
6552 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6553 directory) can be applied to gcc to fix the problem. Alternatively, if you
6554 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6555 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6556 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6559 * New 'maintenance' command
6561 All of the commands related to hacking GDB internals have been moved out of
6562 the main command set, and now live behind the 'maintenance' command. This
6563 can also be abbreviated as 'mt'. The following changes were made:
6565 dump-me -> maintenance dump-me
6566 info all-breakpoints -> maintenance info breakpoints
6567 printmsyms -> maintenance print msyms
6568 printobjfiles -> maintenance print objfiles
6569 printpsyms -> maintenance print psymbols
6570 printsyms -> maintenance print symbols
6572 The following commands are new:
6574 maintenance demangle Call internal GDB demangler routine to
6575 demangle a C++ link name and prints the result.
6576 maintenance print type Print a type chain for a given symbol
6578 * Change to .gdbinit file processing
6580 We now read the $HOME/.gdbinit file before processing the argv arguments
6581 (e.g. reading symbol files or core files). This allows global parameters to
6582 be set, which will apply during the symbol reading. The ./.gdbinit is still
6583 read after argv processing.
6585 * New hosts supported
6587 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6589 GNU/Linux support i386-unknown-linux or linux
6591 We are also including code to support the HP/PA running BSD and HPUX. This
6592 is almost guaranteed not to work, as we didn't have time to test or build it
6593 for this release. We are including it so that the more adventurous (or
6594 masochistic) of you can play with it. We also had major problems with the
6595 fact that the compiler that we got from HP doesn't support the -g option.
6598 * New targets supported
6600 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6602 * More smarts about finding #include files
6604 GDB now remembers the compilation directory for all include files, and for
6605 all files from which C is generated (like yacc and lex sources). This
6606 greatly improves GDB's ability to find yacc/lex sources, and include files,
6607 especially if you are debugging your program from a directory different from
6608 the one that contains your sources.
6610 We also fixed a bug which caused difficulty with listing and setting
6611 breakpoints in include files which contain C code. (In the past, you had to
6612 try twice in order to list an include file that you hadn't looked at before.)
6614 * Interesting infernals change
6616 GDB now deals with arbitrary numbers of sections, where the symbols for each
6617 section must be relocated relative to that section's landing place in the
6618 target's address space. This work was needed to support ELF with embedded
6619 stabs used by Solaris-2.0.
6621 * Bug fixes (of course!)
6623 There have been loads of fixes for the following things:
6624 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6625 i960, stabs, DOS(GO32), procfs, etc...
6627 See the ChangeLog for details.
6629 *** Changes in GDB-4.5:
6631 * New machines supported (host and target)
6633 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6635 SGI Irix-4.x mips-sgi-irix4 or iris4
6637 * New malloc package
6639 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6640 Mmalloc is capable of handling mutiple heaps of memory. It is also
6641 capable of saving a heap to a file, and then mapping it back in later.
6642 This can be used to greatly speedup the startup of GDB by using a
6643 pre-parsed symbol table which lives in a mmalloc managed heap. For
6644 more details, please read mmalloc/mmalloc.texi.
6648 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6649 'help info proc' for details.
6651 * MIPS ecoff symbol table format
6653 The code that reads MIPS symbol table format is now supported on all hosts.
6654 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6657 * File name changes for MS-DOS
6659 Many files in the config directories have been renamed to make it easier to
6660 support GDB on MS-DOSe systems (which have very restrictive file name
6661 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6662 environment) is close to working but has some remaining problems. Note
6663 that debugging of DOS programs is not supported, due to limitations
6664 in the ``operating system'', but it can be used to host cross-debugging.
6666 * Cross byte order fixes
6668 Many fixes have been made to support cross debugging of Sparc and MIPS
6669 targets from hosts whose byte order differs.
6671 * New -mapped and -readnow options
6673 If memory-mapped files are available on your system through the 'mmap'
6674 system call, you can use the -mapped option on the `file' or
6675 `symbol-file' commands to cause GDB to write the symbols from your
6676 program into a reusable file. If the program you are debugging is
6677 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6678 Future GDB debugging sessions will notice the presence of this file,
6679 and will quickly map in symbol information from it, rather than reading
6680 the symbol table from the executable program. Using the '-mapped'
6681 option in a GDB `file' or `symbol-file' command has the same effect as
6682 starting GDB with the '-mapped' command-line option.
6684 You can cause GDB to read the entire symbol table immediately by using
6685 the '-readnow' option with any of the commands that load symbol table
6686 information (or on the GDB command line). This makes the command
6687 slower, but makes future operations faster.
6689 The -mapped and -readnow options are typically combined in order to
6690 build a `fred.syms' file that contains complete symbol information.
6691 A simple GDB invocation to do nothing but build a `.syms' file for future
6694 gdb -batch -nx -mapped -readnow programname
6696 The `.syms' file is specific to the host machine on which GDB is run.
6697 It holds an exact image of GDB's internal symbol table. It cannot be
6698 shared across multiple host platforms.
6700 * longjmp() handling
6702 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6703 siglongjmp() without losing control. This feature has not yet been ported to
6704 all systems. It currently works on many 386 platforms, all MIPS-based
6705 platforms (SGI, DECstation, etc), and Sun3/4.
6709 Preliminary work has been put in to support the new Solaris OS from Sun. At
6710 this time, it can control and debug processes, but it is not capable of
6715 As always, many many bug fixes. The major areas were with g++, and mipsread.
6716 People using the MIPS-based platforms should experience fewer mysterious
6717 crashes and trashed symbol tables.
6719 *** Changes in GDB-4.4:
6721 * New machines supported (host and target)
6723 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6725 BSD Reno on Vax vax-dec-bsd
6726 Ultrix on Vax vax-dec-ultrix
6728 * New machines supported (target)
6730 AMD 29000 embedded, using EBMON a29k-none-none
6734 GDB continues to improve its handling of C++. `References' work better.
6735 The demangler has also been improved, and now deals with symbols mangled as
6736 per the Annotated C++ Reference Guide.
6738 GDB also now handles `stabs' symbol information embedded in MIPS
6739 `ecoff' symbol tables. Since the ecoff format was not easily
6740 extensible to handle new languages such as C++, this appeared to be a
6741 good way to put C++ debugging info into MIPS binaries. This option
6742 will be supported in the GNU C compiler, version 2, when it is
6745 * New features for SVR4
6747 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6748 shared libraries. Debugging dynamically linked programs should present
6749 only minor differences from debugging statically linked programs.
6751 The `info proc' command will print out information about any process
6752 on an SVR4 system (including the one you are debugging). At the moment,
6753 it prints the address mappings of the process.
6755 If you bring up GDB on another SVR4 system, please send mail to
6756 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6758 * Better dynamic linking support in SunOS
6760 Reading symbols from shared libraries which contain debugging symbols
6761 now works properly. However, there remain issues such as automatic
6762 skipping of `transfer vector' code during function calls, which
6763 make it harder to debug code in a shared library, than to debug the
6764 same code linked statically.
6768 GDB is now using the latest `getopt' routines from the FSF. This
6769 version accepts the -- prefix for options with long names. GDB will
6770 continue to accept the old forms (-option and +option) as well.
6771 Various single letter abbreviations for options have been explicity
6772 added to the option table so that they won't get overshadowed in the
6773 future by other options that begin with the same letter.
6777 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6778 Many assorted bugs have been handled. Many more remain to be handled.
6779 See the various ChangeLog files (primarily in gdb and bfd) for details.
6782 *** Changes in GDB-4.3:
6784 * New machines supported (host and target)
6786 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6787 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6788 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6790 * Almost SCO Unix support
6792 We had hoped to support:
6793 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6794 (except for core file support), but we discovered very late in the release
6795 that it has problems with process groups that render gdb unusable. Sorry
6796 about that. I encourage people to fix it and post the fixes.
6798 * Preliminary ELF and DWARF support
6800 GDB can read ELF object files on System V Release 4, and can handle
6801 debugging records for C, in DWARF format, in ELF files. This support
6802 is preliminary. If you bring up GDB on another SVR4 system, please
6803 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6808 GDB now uses the latest `readline' library. One user-visible change
6809 is that two tabs will list possible command completions, which previously
6810 required typing M-? (meta-question mark, or ESC ?).
6814 The `stepi' bug that many of you noticed has been squashed.
6815 Many bugs in C++ have been handled. Many more remain to be handled.
6816 See the various ChangeLog files (primarily in gdb and bfd) for details.
6818 * State of the MIPS world (in case you wondered):
6820 GDB can understand the symbol tables emitted by the compilers
6821 supplied by most vendors of MIPS-based machines, including DEC. These
6822 symbol tables are in a format that essentially nobody else uses.
6824 Some versions of gcc come with an assembler post-processor called
6825 mips-tfile. This program is required if you want to do source-level
6826 debugging of gcc-compiled programs. I believe FSF does not ship
6827 mips-tfile with gcc version 1, but it will eventually come with gcc
6830 Debugging of g++ output remains a problem. g++ version 1.xx does not
6831 really support it at all. (If you're lucky, you should be able to get
6832 line numbers and stack traces to work, but no parameters or local
6833 variables.) With some work it should be possible to improve the
6836 When gcc version 2 is released, you will have somewhat better luck.
6837 However, even then you will get confusing results for inheritance and
6840 We will eventually provide full debugging of g++ output on
6841 DECstations. This will probably involve some kind of stabs-in-ecoff
6842 encapulation, but the details have not been worked out yet.
6845 *** Changes in GDB-4.2:
6847 * Improved configuration
6849 Only one copy of `configure' exists now, and it is not self-modifying.
6850 Porting BFD is simpler.
6854 The `step' and `next' commands now only stop at the first instruction
6855 of a source line. This prevents the multiple stops that used to occur
6856 in switch statements, for-loops, etc. `Step' continues to stop if a
6857 function that has debugging information is called within the line.
6861 Lots of small bugs fixed. More remain.
6863 * New host supported (not target)
6865 Intel 386 PC clone running Mach i386-none-mach
6868 *** Changes in GDB-4.1:
6870 * Multiple source language support
6872 GDB now has internal scaffolding to handle several source languages.
6873 It determines the type of each source file from its filename extension,
6874 and will switch expression parsing and number formatting to match the
6875 language of the function in the currently selected stack frame.
6876 You can also specifically set the language to be used, with
6877 `set language c' or `set language modula-2'.
6881 GDB now has preliminary support for the GNU Modula-2 compiler,
6882 currently under development at the State University of New York at
6883 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6884 continue through the fall of 1991 and into 1992.
6886 Other Modula-2 compilers are currently not supported, and attempting to
6887 debug programs compiled with them will likely result in an error as the
6888 symbol table is read. Feel free to work on it, though!
6890 There are hooks in GDB for strict type checking and range checking,
6891 in the `Modula-2 philosophy', but they do not currently work.
6895 GDB can now write to executable and core files (e.g. patch
6896 a variable's value). You must turn this switch on, specify
6897 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6898 by assigning a new value to a variable. Modifications take
6901 * Automatic SunOS shared library reading
6903 When you run your program, GDB automatically determines where its
6904 shared libraries (if any) have been loaded, and reads their symbols.
6905 The `share' command is no longer needed. This also works when
6906 examining core files.
6910 You can specify the number of lines that the `list' command shows.
6913 * New machines supported (host and target)
6915 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6916 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6917 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6919 * New hosts supported (not targets)
6921 IBM RT/PC: romp-ibm-aix or rtpc
6923 * New targets supported (not hosts)
6925 AMD 29000 embedded with COFF a29k-none-coff
6926 AMD 29000 embedded with a.out a29k-none-aout
6927 Ultracomputer remote kernel debug a29k-nyu-kern
6929 * New remote interfaces
6935 *** Changes in GDB-4.0:
6939 Wide output is wrapped at good places to make the output more readable.
6941 Gdb now supports cross-debugging from a host machine of one type to a
6942 target machine of another type. Communication with the target system
6943 is over serial lines. The ``target'' command handles connecting to the
6944 remote system; the ``load'' command will download a program into the
6945 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6946 also supports debugging of realtime processes running under VxWorks,
6947 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6948 stub on the target system.
6950 New CPUs supported include the AMD 29000 and Intel 960.
6952 GDB now reads object files and symbol tables via a ``binary file''
6953 library, which allows a single copy of GDB to debug programs of multiple
6954 object file types such as a.out and coff.
6956 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6957 refcard.dvi and refcard.ps are available to format it).
6960 * Control-Variable user interface simplified
6962 All variables that control the operation of the debugger can be set
6963 by the ``set'' command, and displayed by the ``show'' command.
6965 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6966 ``Show prompt'' produces the response:
6967 Gdb's prompt is new-gdb=>.
6969 What follows are the NEW set commands. The command ``help set'' will
6970 print a complete list of old and new set commands. ``help set FOO''
6971 will give a longer description of the variable FOO. ``show'' will show
6972 all of the variable descriptions and their current settings.
6974 confirm on/off: Enables warning questions for operations that are
6975 hard to recover from, e.g. rerunning the program while
6976 it is already running. Default is ON.
6978 editing on/off: Enables EMACS style command line editing
6979 of input. Previous lines can be recalled with
6980 control-P, the current line can be edited with control-B,
6981 you can search for commands with control-R, etc.
6984 history filename NAME: NAME is where the gdb command history
6985 will be stored. The default is .gdb_history,
6986 or the value of the environment variable
6989 history size N: The size, in commands, of the command history. The
6990 default is 256, or the value of the environment variable
6993 history save on/off: If this value is set to ON, the history file will
6994 be saved after exiting gdb. If set to OFF, the
6995 file will not be saved. The default is OFF.
6997 history expansion on/off: If this value is set to ON, then csh-like
6998 history expansion will be performed on
6999 command line input. The default is OFF.
7001 radix N: Sets the default radix for input and output. It can be set
7002 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7003 in the current radix, so "set radix 10" is always a no-op.
7005 height N: This integer value is the number of lines on a page. Default
7006 is 24, the current `stty rows'' setting, or the ``li#''
7007 setting from the termcap entry matching the environment
7010 width N: This integer value is the number of characters on a line.
7011 Default is 80, the current `stty cols'' setting, or the ``co#''
7012 setting from the termcap entry matching the environment
7015 Note: ``set screensize'' is obsolete. Use ``set height'' and
7016 ``set width'' instead.
7018 print address on/off: Print memory addresses in various command displays,
7019 such as stack traces and structure values. Gdb looks
7020 more ``symbolic'' if you turn this off; it looks more
7021 ``machine level'' with it on. Default is ON.
7023 print array on/off: Prettyprint arrays. New convenient format! Default
7026 print demangle on/off: Print C++ symbols in "source" form if on,
7029 print asm-demangle on/off: Same, for assembler level printouts
7032 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7035 * Support for Epoch Environment.
7037 The epoch environment is a version of Emacs v18 with windowing. One
7038 new command, ``inspect'', is identical to ``print'', except that if you
7039 are running in the epoch environment, the value is printed in its own
7043 * Support for Shared Libraries
7045 GDB can now debug programs and core files that use SunOS shared libraries.
7046 Symbols from a shared library cannot be referenced
7047 before the shared library has been linked with the program (this
7048 happens after you type ``run'' and before the function main() is entered).
7049 At any time after this linking (including when examining core files
7050 from dynamically linked programs), gdb reads the symbols from each
7051 shared library when you type the ``sharedlibrary'' command.
7052 It can be abbreviated ``share''.
7054 sharedlibrary REGEXP: Load shared object library symbols for files
7055 matching a unix regular expression. No argument
7056 indicates to load symbols for all shared libraries.
7058 info sharedlibrary: Status of loaded shared libraries.
7063 A watchpoint stops execution of a program whenever the value of an
7064 expression changes. Checking for this slows down execution
7065 tremendously whenever you are in the scope of the expression, but is
7066 quite useful for catching tough ``bit-spreader'' or pointer misuse
7067 problems. Some machines such as the 386 have hardware for doing this
7068 more quickly, and future versions of gdb will use this hardware.
7070 watch EXP: Set a watchpoint (breakpoint) for an expression.
7072 info watchpoints: Information about your watchpoints.
7074 delete N: Deletes watchpoint number N (same as breakpoints).
7075 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7076 enable N: Re-enables watchpoint number N (same as breakpoints).
7079 * C++ multiple inheritance
7081 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7084 * C++ exception handling
7086 Gdb now supports limited C++ exception handling. Besides the existing
7087 ability to breakpoint on an exception handler, gdb can breakpoint on
7088 the raising of an exception (before the stack is peeled back to the
7091 catch FOO: If there is a FOO exception handler in the dynamic scope,
7092 set a breakpoint to catch exceptions which may be raised there.
7093 Multiple exceptions (``catch foo bar baz'') may be caught.
7095 info catch: Lists all exceptions which may be caught in the
7096 current stack frame.
7099 * Minor command changes
7101 The command ``call func (arg, arg, ...)'' now acts like the print
7102 command, except it does not print or save a value if the function's result
7103 is void. This is similar to dbx usage.
7105 The ``up'' and ``down'' commands now always print the frame they end up
7106 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7107 frames without printing.
7109 * New directory command
7111 'dir' now adds directories to the FRONT of the source search path.
7112 The path starts off empty. Source files that contain debug information
7113 about the directory in which they were compiled can be found even
7114 with an empty path; Sun CC and GCC include this information. If GDB can't
7115 find your source file in the current directory, type "dir .".
7117 * Configuring GDB for compilation
7119 For normal use, type ``./configure host''. See README or gdb.texinfo
7122 GDB now handles cross debugging. If you are remotely debugging between
7123 two different machines, type ``./configure host -target=targ''.
7124 Host is the machine where GDB will run; targ is the machine
7125 where the program that you are debugging will run.