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 * New native configurations
54 GNU/Linux/RISC-V riscv*-*-linux*
58 GNU/Linux/RISC-V riscv*-*-linux*
60 *** Changes in GDB 8.2
62 * The 'set disassembler-options' command now supports specifying options
65 * The 'symbol-file' command now accepts an '-o' option to add a relative
66 offset to all sections.
68 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
69 a relative offset to all sections, but it allows to override the load
70 address of individual sections using '-s'.
72 * The 'add-symbol-file' command no longer requires the second argument
73 (address of the text section).
75 * The endianness used with the 'set endian auto' mode in the absence of
76 an executable selected for debugging is now the last endianness chosen
77 either by one of the 'set endian big' and 'set endian little' commands
78 or by inferring from the last executable used, rather than the startup
81 * The pager now allows a "c" response, meaning to disable the pager
82 for the rest of the current command.
84 * The commands 'info variables/functions/types' now show the source line
85 numbers of symbol definitions when available.
87 * 'info proc' now works on running processes on FreeBSD systems and core
88 files created on FreeBSD systems.
90 * C expressions can now use _Alignof, and C++ expressions can now use
97 Control display of debugging info regarding the FreeBSD native target.
99 set|show varsize-limit
100 This new setting allows the user to control the maximum size of Ada
101 objects being printed when those objects have a variable type,
102 instead of that maximum size being hardcoded to 65536 bytes.
104 set|show record btrace cpu
105 Controls the processor to be used for enabling errata workarounds for
108 maint check libthread-db
109 Run integrity checks on the current inferior's thread debugging
112 maint set check-libthread-db (on|off)
113 maint show check-libthread-db
114 Control whether to run integrity checks on inferior specific thread
115 debugging libraries as they are loaded. The default is not to
120 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
122 ** The commands attached to a breakpoint can be set by assigning to
123 the breakpoint's "commands" field.
125 ** gdb.execute can now execute multi-line gdb commands.
127 ** The new functions gdb.convenience_variable and
128 gdb.set_convenience_variable can be used to get and set the value
129 of convenience variables.
131 ** A gdb.Parameter will no longer print the "set" help text on an
132 ordinary "set"; instead by default a "set" will be silent unless
133 the get_set_string method returns a non-empty string.
137 RiscV ELF riscv*-*-elf
139 * Removed targets and native configurations
141 m88k running OpenBSD m88*-*-openbsd*
142 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
143 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
144 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
146 * Aarch64/Linux hardware watchpoints improvements
148 Hardware watchpoints on unaligned addresses are now properly
149 supported when running Linux kernel 4.10 or higher: read and access
150 watchpoints are no longer spuriously missed, and all watchpoints
151 lengths between 1 and 8 bytes are supported. On older kernels,
152 watchpoints set on unaligned addresses are no longer missed, with
153 the tradeoff that there is a possibility of false hits being
158 --enable-codesign=CERT
159 This can be used to invoke "codesign -s CERT" after building gdb.
160 This option is useful on macOS, where code signing is required for
161 gdb to work properly.
163 --disable-gdbcli has been removed
164 This is now silently accepted, but does nothing.
166 *** Changes in GDB 8.1
168 * GDB now supports dynamically creating arbitrary register groups specified
169 in XML target descriptions. This allows for finer grain grouping of
170 registers on systems with a large amount of registers.
172 * The 'ptype' command now accepts a '/o' flag, which prints the
173 offsets and sizes of fields in a struct, like the pahole(1) tool.
175 * New "--readnever" command line option instructs GDB to not read each
176 symbol file's symbolic debug information. This makes startup faster
177 but at the expense of not being able to perform symbolic debugging.
178 This option is intended for use cases where symbolic debugging will
179 not be used, e.g., when you only need to dump the debuggee's core.
181 * GDB now uses the GNU MPFR library, if available, to emulate target
182 floating-point arithmetic during expression evaluation when the target
183 uses different floating-point formats than the host. At least version
184 3.1 of GNU MPFR is required.
186 * GDB now supports access to the guarded-storage-control registers and the
187 software-based guarded-storage broadcast control registers on IBM z14.
189 * On Unix systems, GDB now supports transmitting environment variables
190 that are to be set or unset to GDBserver. These variables will
191 affect the environment to be passed to the remote inferior.
193 To inform GDB of environment variables that are to be transmitted to
194 GDBserver, use the "set environment" command. Only user set
195 environment variables are sent to GDBserver.
197 To inform GDB of environment variables that are to be unset before
198 the remote inferior is started by the GDBserver, use the "unset
199 environment" command.
201 * Completion improvements
203 ** GDB can now complete function parameters in linespecs and
204 explicit locations without quoting. When setting breakpoints,
205 quoting around functions names to help with TAB-completion is
206 generally no longer necessary. For example, this now completes
209 (gdb) b function(in[TAB]
210 (gdb) b function(int)
212 Related, GDB is no longer confused with completing functions in
213 C++ anonymous namespaces:
216 (gdb) b (anonymous namespace)::[TAB][TAB]
217 (anonymous namespace)::a_function()
218 (anonymous namespace)::b_function()
220 ** GDB now has much improved linespec and explicit locations TAB
221 completion support, that better understands what you're
222 completing and offers better suggestions. For example, GDB no
223 longer offers data symbols as possible completions when you're
224 setting a breakpoint.
226 ** GDB now TAB-completes label symbol names.
228 ** The "complete" command now mimics TAB completion accurately.
230 * New command line options (gcore)
233 Dump all memory mappings.
235 * Breakpoints on C++ functions are now set on all scopes by default
237 By default, breakpoints on functions/methods are now interpreted as
238 specifying all functions with the given name ignoring missing
239 leading scopes (namespaces and classes).
241 For example, assuming a C++ program with symbols named:
246 both commands "break func()" and "break B::func()" set a breakpoint
249 You can use the new flag "-qualified" to override this. This makes
250 GDB interpret the specified function name as a complete
251 fully-qualified name instead. For example, using the same C++
252 program, the "break -q B::func" command sets a breakpoint on
253 "B::func", only. A parameter has been added to the Python
254 gdb.Breakpoint constructor to achieve the same result when creating
255 a breakpoint from Python.
257 * Breakpoints on functions marked with C++ ABI tags
259 GDB can now set breakpoints on functions marked with C++ ABI tags
260 (e.g., [abi:cxx11]). See here for a description of ABI tags:
261 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
263 Functions with a C++11 abi tag are demangled/displayed like this:
265 function[abi:cxx11](int)
268 You can now set a breakpoint on such functions simply as if they had
271 (gdb) b function(int)
273 Or if you need to disambiguate between tags, like:
275 (gdb) b function[abi:other_tag](int)
277 Tab completion was adjusted accordingly as well.
281 ** New events gdb.new_inferior, gdb.inferior_deleted, and
282 gdb.new_thread are emitted. See the manual for further
283 description of these.
285 ** A new function, "gdb.rbreak" has been added to the Python API.
286 This function allows the setting of a large number of breakpoints
287 via a regex pattern in Python. See the manual for further details.
289 ** Python breakpoints can now accept explicit locations. See the
290 manual for a further description of this feature.
293 * New features in the GDB remote stub, GDBserver
295 ** GDBserver is now able to start inferior processes with a
296 specified initial working directory.
298 The user can set the desired working directory to be used from
299 GDB using the new "set cwd" command.
301 ** New "--selftest" command line option runs some GDBserver self
302 tests. These self tests are disabled in releases.
304 ** On Unix systems, GDBserver now does globbing expansion and variable
305 substitution in inferior command line arguments.
307 This is done by starting inferiors using a shell, like GDB does.
308 See "set startup-with-shell" in the user manual for how to disable
309 this from GDB when using "target extended-remote". When using
310 "target remote", you can disable the startup with shell by using the
311 new "--no-startup-with-shell" GDBserver command line option.
313 ** On Unix systems, GDBserver now supports receiving environment
314 variables that are to be set or unset from GDB. These variables
315 will affect the environment to be passed to the inferior.
317 * When catching an Ada exception raised with a message, GDB now prints
318 the message in the catchpoint hit notification. In GDB/MI mode, that
319 information is provided as an extra field named "exception-message"
320 in the *stopped notification.
322 * Trait objects can now be inspected When debugging Rust code. This
323 requires compiler support which will appear in Rust 1.24.
327 QEnvironmentHexEncoded
328 Inform GDBserver of an environment variable that is to be passed to
329 the inferior when starting it.
332 Inform GDBserver of an environment variable that is to be unset
333 before starting the remote inferior.
336 Inform GDBserver that the environment should be reset (i.e.,
337 user-set environment variables should be unset).
340 Indicates whether the inferior must be started with a shell or not.
343 Tell GDBserver that the inferior to be started should use a specific
346 * The "maintenance print c-tdesc" command now takes an optional
347 argument which is the file name of XML target description.
349 * The "maintenance selftest" command now takes an optional argument to
350 filter the tests to be run.
352 * The "enable", and "disable" commands now accept a range of
353 breakpoint locations, e.g. "enable 1.3-5".
358 Set and show the current working directory for the inferior.
361 Set and show compilation command used for compiling and injecting code
362 with the 'compile' commands.
364 set debug separate-debug-file
365 show debug separate-debug-file
366 Control the display of debug output about separate debug file search.
368 set dump-excluded-mappings
369 show dump-excluded-mappings
370 Control whether mappings marked with the VM_DONTDUMP flag should be
371 dumped when generating a core file.
374 List the registered selftests.
377 Start the debugged program stopping at the first instruction.
380 Control display of debugging messages related to OpenRISC targets.
382 set|show print type nested-type-limit
383 Set and show the limit of nesting level for nested types that the
384 type printer will show.
386 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
389 * Safer/improved support for debugging with no debug info
391 GDB no longer assumes functions with no debug information return
394 This means that GDB now refuses to call such functions unless you
395 tell it the function's type, by either casting the call to the
396 declared return type, or by casting the function to a function
397 pointer of the right type, and calling that:
399 (gdb) p getenv ("PATH")
400 'getenv' has unknown return type; cast the call to its declared return type
401 (gdb) p (char *) getenv ("PATH")
402 $1 = 0x7fffffffe "/usr/local/bin:/"...
403 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
404 $2 = 0x7fffffffe "/usr/local/bin:/"...
406 Similarly, GDB no longer assumes that global variables with no debug
407 info have type 'int', and refuses to print the variable's value
408 unless you tell it the variable's type:
411 'var' has unknown type; cast it to its declared type
415 * New native configurations
417 FreeBSD/aarch64 aarch64*-*-freebsd*
418 FreeBSD/arm arm*-*-freebsd*
422 FreeBSD/aarch64 aarch64*-*-freebsd*
423 FreeBSD/arm arm*-*-freebsd*
424 OpenRISC ELF or1k*-*-elf
426 * Removed targets and native configurations
428 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
430 *** Changes in GDB 8.0
432 * GDB now supports access to the PKU register on GNU/Linux. The register is
433 added by the Memory Protection Keys for Userspace feature which will be
434 available in future Intel CPUs.
436 * GDB now supports C++11 rvalue references.
440 ** New functions to start, stop and access a running btrace recording.
441 ** Rvalue references are now supported in gdb.Type.
443 * GDB now supports recording and replaying rdrand and rdseed Intel 64
446 * Building GDB and GDBserver now requires a C++11 compiler.
448 For example, GCC 4.8 or later.
450 It is no longer possible to build GDB or GDBserver with a C
451 compiler. The --disable-build-with-cxx configure option has been
454 * Building GDB and GDBserver now requires GNU make >= 3.81.
456 It is no longer supported to build GDB or GDBserver with another
457 implementation of the make program or an earlier version of GNU make.
459 * Native debugging on MS-Windows supports command-line redirection
461 Command-line arguments used for starting programs on MS-Windows can
462 now include redirection symbols supported by native Windows shells,
463 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
464 as "run", "start", and "set args", as well as the corresponding MI
467 * Support for thread names on MS-Windows.
469 GDB now catches and handles the special exception that programs
470 running on MS-Windows use to assign names to threads in the
473 * Support for Java programs compiled with gcj has been removed.
475 * User commands now accept an unlimited number of arguments.
476 Previously, only up to 10 was accepted.
478 * The "eval" command now expands user-defined command arguments.
480 This makes it easier to process a variable number of arguments:
485 eval "print $arg%d", $i
490 * Target descriptions can now describe registers for sparc32 and sparc64.
492 * GDB now supports DWARF version 5 (debug information format).
493 Its .debug_names index is not yet supported.
495 * New native configurations
497 FreeBSD/mips mips*-*-freebsd
501 Synopsys ARC arc*-*-elf32
502 FreeBSD/mips mips*-*-freebsd
504 * Removed targets and native configurations
506 Alpha running FreeBSD alpha*-*-freebsd*
507 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
512 Erases all the flash memory regions reported by the target.
514 maint print arc arc-instruction address
515 Print internal disassembler information about instruction at a given address.
519 set disassembler-options
520 show disassembler-options
521 Controls the passing of target specific information to the disassembler.
522 If it is necessary to specify more than one disassembler option then
523 multiple options can be placed together into a comma separated list.
524 The default value is the empty string. Currently, the only supported
525 targets are ARM, PowerPC and S/390.
530 Erases all the flash memory regions reported by the target. This is
531 equivalent to the CLI command flash-erase.
533 -file-list-shared-libraries
534 List the shared libraries in the program. This is
535 equivalent to the CLI command "info shared".
538 Catchpoints stopping the program when Ada exceptions are
539 handled. This is equivalent to the CLI command "catch handlers".
541 *** Changes in GDB 7.12
543 * GDB and GDBserver now build with a C++ compiler by default.
545 The --enable-build-with-cxx configure option is now enabled by
546 default. One must now explicitly configure with
547 --disable-build-with-cxx in order to build with a C compiler. This
548 option will be removed in a future release.
550 * GDBserver now supports recording btrace without maintaining an active
553 * GDB now supports a negative repeat count in the 'x' command to examine
554 memory backward from the given address. For example:
557 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
558 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
559 (gdb) x/-5i 0x0000000000400580
560 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
561 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
562 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
563 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
564 0x40057b <main(int, char**)+25>:
565 callq 0x400536 <Func1(int, char const*)>
567 * Fortran: Support structures with fields of dynamic types and
568 arrays of dynamic types.
570 * The symbol dumping maintenance commands have new syntax.
571 maint print symbols [-pc address] [--] [filename]
572 maint print symbols [-objfile objfile] [-source source] [--] [filename]
573 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
574 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
575 maint print msymbols [-objfile objfile] [--] [filename]
577 * GDB now supports multibit bitfields and enums in target register
580 * New Python-based convenience function $_as_string(val), which returns
581 the textual representation of a value. This function is especially
582 useful to obtain the text label of an enum value.
584 * Intel MPX bound violation handling.
586 Segmentation faults caused by a Intel MPX boundary violation
587 now display the kind of violation (upper or lower), the memory
588 address accessed and the memory bounds, along with the usual
589 signal received and code location.
593 Program received signal SIGSEGV, Segmentation fault
594 Upper bound violation while accessing address 0x7fffffffc3b3
595 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
596 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
598 * Rust language support.
599 GDB now supports debugging programs written in the Rust programming
600 language. See https://www.rust-lang.org/ for more information about
603 * Support for running interpreters on specified input/output devices
605 GDB now supports a new mechanism that allows frontends to provide
606 fully featured GDB console views, as a better alternative to
607 building such views on top of the "-interpreter-exec console"
608 command. See the new "new-ui" command below. With that command,
609 frontends can now start GDB in the traditional command-line mode
610 running in an embedded terminal emulator widget, and create a
611 separate MI interpreter running on a specified i/o device. In this
612 way, GDB handles line editing, history, tab completion, etc. in the
613 console all by itself, and the GUI uses the separate MI interpreter
614 for its own control and synchronization, invisible to the command
617 * The "catch syscall" command catches groups of related syscalls.
619 The "catch syscall" command now supports catching a group of related
620 syscalls using the 'group:' or 'g:' prefix.
625 skip -gfile file-glob-pattern
626 skip -function function
627 skip -rfunction regular-expression
628 A generalized form of the skip command, with new support for
629 glob-style file names and regular expressions for function names.
630 Additionally, a file spec and a function spec may now be combined.
632 maint info line-table REGEXP
633 Display the contents of GDB's internal line table data struture.
636 Run any GDB unit tests that were compiled in.
639 Start a new user interface instance running INTERP as interpreter,
640 using the TTY file for input/output.
644 ** gdb.Breakpoint objects have a new attribute "pending", which
645 indicates whether the breakpoint is pending.
646 ** Three new breakpoint-related events have been added:
647 gdb.breakpoint_created, gdb.breakpoint_modified, and
648 gdb.breakpoint_deleted.
651 Signal ("set") the given MS-Windows event object. This is used in
652 conjunction with the Windows JIT debugging (AeDebug) support, where
653 the OS suspends a crashing process until a debugger can attach to
654 it. Resuming the crashing process, in order to debug it, is done by
657 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
658 was added in GDBserver, including JIT compiling fast tracepoint's
659 conditional expression bytecode into native code.
661 * Support for various remote target protocols and ROM monitors has
664 target m32rsdi Remote M32R debugging over SDI
665 target mips MIPS remote debugging protocol
666 target pmon PMON ROM monitor
667 target ddb NEC's DDB variant of PMON for Vr4300
668 target rockhopper NEC RockHopper variant of PMON
669 target lsi LSI variant of PMO
671 * Support for tracepoints and fast tracepoints on powerpc-linux,
672 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
673 including JIT compiling fast tracepoint's conditional expression
674 bytecode into native code.
676 * MI async record =record-started now includes the method and format used for
677 recording. For example:
679 =record-started,thread-group="i1",method="btrace",format="bts"
681 * MI async record =thread-selected now includes the frame field. For example:
683 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
687 Andes NDS32 nds32*-*-elf
689 *** Changes in GDB 7.11
691 * GDB now supports debugging kernel-based threads on FreeBSD.
693 * Per-inferior thread numbers
695 Thread numbers are now per inferior instead of global. If you're
696 debugging multiple inferiors, GDB displays thread IDs using a
697 qualified INF_NUM.THR_NUM form. For example:
701 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
702 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
703 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
704 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
706 As consequence, thread numbers as visible in the $_thread
707 convenience variable and in Python's InferiorThread.num attribute
708 are no longer unique between inferiors.
710 GDB now maintains a second thread ID per thread, referred to as the
711 global thread ID, which is the new equivalent of thread numbers in
712 previous releases. See also $_gthread below.
714 For backwards compatibility, MI's thread IDs always refer to global
717 * Commands that accept thread IDs now accept the qualified
718 INF_NUM.THR_NUM form as well. For example:
721 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
724 * In commands that accept a list of thread IDs, you can now refer to
725 all threads of an inferior using a star wildcard. GDB accepts
726 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
727 refer to all threads of the current inferior. For example, "info
730 * You can use "info threads -gid" to display the global thread ID of
733 * The new convenience variable $_gthread holds the global number of
736 * The new convenience variable $_inferior holds the number of the
739 * GDB now displays the ID and name of the thread that hit a breakpoint
740 or received a signal, if your program is multi-threaded. For
743 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
744 Thread 1 "main" received signal SIGINT, Interrupt.
746 * Record btrace now supports non-stop mode.
748 * Support for tracepoints on aarch64-linux was added in GDBserver.
750 * The 'record instruction-history' command now indicates speculative execution
751 when using the Intel Processor Trace recording format.
753 * GDB now allows users to specify explicit locations, bypassing
754 the linespec parser. This feature is also available to GDB/MI
757 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
758 GDB now is able to debug both AArch64 applications and ARM applications
761 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
762 including JIT compiling fast tracepoint's conditional expression bytecode
765 * GDB now supports displaced stepping on AArch64 GNU/Linux.
767 * "info threads", "info inferiors", "info display", "info checkpoints"
768 and "maint info program-spaces" now list the corresponding items in
769 ascending ID order, for consistency with all other "info" commands.
771 * In Ada, the overloads selection menu has been enhanced to display the
772 parameter types and the return types for the matching overloaded subprograms.
776 maint set target-non-stop (on|off|auto)
777 maint show target-non-stop
778 Control whether GDB targets always operate in non-stop mode even if
779 "set non-stop" is "off". The default is "auto", meaning non-stop
780 mode is enabled if supported by the target.
782 maint set bfd-sharing
783 maint show bfd-sharing
784 Control the reuse of bfd objects.
788 Control display of debugging info regarding bfd caching.
792 Control display of debugging info regarding FreeBSD threads.
794 set remote multiprocess-extensions-packet
795 show remote multiprocess-extensions-packet
796 Set/show the use of the remote protocol multiprocess extensions.
798 set remote thread-events
799 show remote thread-events
800 Set/show the use of thread create/exit events.
802 set ada print-signatures on|off
803 show ada print-signatures"
804 Control whether parameter types and return types are displayed in overloads
805 selection menus. It is activaled (@code{on}) by default.
809 Controls the maximum size of memory, in bytes, that GDB will
810 allocate for value contents. Prevents incorrect programs from
811 causing GDB to allocate overly large buffers. Default is 64k.
813 * The "disassemble" command accepts a new modifier: /s.
814 It prints mixed source+disassembly like /m with two differences:
815 - disassembled instructions are now printed in program order, and
816 - and source for all relevant files is now printed.
817 The "/m" option is now considered deprecated: its "source-centric"
818 output hasn't proved useful in practice.
820 * The "record instruction-history" command accepts a new modifier: /s.
821 It behaves exactly like /m and prints mixed source+disassembly.
823 * The "set scheduler-locking" command supports a new mode "replay".
824 It behaves like "off" in record mode and like "on" in replay mode.
826 * Support for various ROM monitors has been removed:
828 target dbug dBUG ROM monitor for Motorola ColdFire
829 target picobug Motorola picobug monitor
830 target dink32 DINK32 ROM monitor for PowerPC
831 target m32r Renesas M32R/D ROM monitor
832 target mon2000 mon2000 ROM monitor
833 target ppcbug PPCBUG ROM monitor for PowerPC
835 * Support for reading/writing memory and extracting values on architectures
836 whose memory is addressable in units of any integral multiple of 8 bits.
839 Allows to break when an Ada exception is handled.
844 Indicates that an exec system call was executed.
846 exec-events feature in qSupported
847 The qSupported packet allows GDB to request support for exec
848 events using the new 'gdbfeature' exec-event, and the qSupported
849 response can contain the corresponding 'stubfeature'. Set and
850 show commands can be used to display whether these features are enabled.
853 Equivalent to interrupting with the ^C character, but works in
856 thread created stop reason (T05 create:...)
857 Indicates that the thread was just created and is stopped at entry.
859 thread exit stop reply (w exitcode;tid)
860 Indicates that the thread has terminated.
863 Enables/disables thread create and exit event reporting. For
864 example, this is used in non-stop mode when GDB stops a set of
865 threads and synchronously waits for the their corresponding stop
866 replies. Without exit events, if one of the threads exits, GDB
867 would hang forever not knowing that it should no longer expect a
868 stop for that same thread.
871 Indicates that there are no resumed threads left in the target (all
872 threads are stopped). The remote stub reports support for this stop
873 reply to GDB's qSupported query.
876 Enables/disables catching syscalls from the inferior process.
877 The remote stub reports support for this packet to GDB's qSupported query.
879 syscall_entry stop reason
880 Indicates that a syscall was just called.
882 syscall_return stop reason
883 Indicates that a syscall just returned.
885 * Extended-remote exec events
887 ** GDB now has support for exec events on extended-remote Linux targets.
888 For such targets with Linux kernels 2.5.46 and later, this enables
889 follow-exec-mode and exec catchpoints.
891 set remote exec-event-feature-packet
892 show remote exec-event-feature-packet
893 Set/show the use of the remote exec event feature.
895 * Thread names in remote protocol
897 The reply to qXfer:threads:read may now include a name attribute for each
900 * Target remote mode fork and exec events
902 ** GDB now has support for fork and exec events on target remote mode
903 Linux targets. For such targets with Linux kernels 2.5.46 and later,
904 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
905 fork and exec catchpoints.
907 * Remote syscall events
909 ** GDB now has support for catch syscall on remote Linux targets,
910 currently enabled on x86/x86_64 architectures.
912 set remote catch-syscall-packet
913 show remote catch-syscall-packet
914 Set/show the use of the remote catch syscall feature.
918 ** The -var-set-format command now accepts the zero-hexadecimal
919 format. It outputs data in hexadecimal format with zero-padding on the
924 ** gdb.InferiorThread objects have a new attribute "global_num",
925 which refers to the thread's global thread ID. The existing
926 "num" attribute now refers to the thread's per-inferior number.
927 See "Per-inferior thread numbers" above.
928 ** gdb.InferiorThread objects have a new attribute "inferior", which
929 is the Inferior object the thread belongs to.
931 *** Changes in GDB 7.10
933 * Support for process record-replay and reverse debugging on aarch64*-linux*
934 targets has been added. GDB now supports recording of A64 instruction set
935 including advance SIMD instructions.
937 * Support for Sun's version of the "stabs" debug file format has been removed.
939 * GDB now honors the content of the file /proc/PID/coredump_filter
940 (PID is the process ID) on GNU/Linux systems. This file can be used
941 to specify the types of memory mappings that will be included in a
942 corefile. For more information, please refer to the manual page of
943 "core(5)". GDB also has a new command: "set use-coredump-filter
944 on|off". It allows to set whether GDB will read the content of the
945 /proc/PID/coredump_filter file when generating a corefile.
947 * The "info os" command on GNU/Linux can now display information on
949 "info os cpus" Listing of all cpus/cores on the system
951 * GDB has two new commands: "set serial parity odd|even|none" and
952 "show serial parity". These allows to set or show parity for the
955 * The "info source" command now displays the producer string if it was
956 present in the debug info. This typically includes the compiler version
957 and may include things like its command line arguments.
959 * The "info dll", an alias of the "info sharedlibrary" command,
960 is now available on all platforms.
962 * Directory names supplied to the "set sysroot" commands may be
963 prefixed with "target:" to tell GDB to access shared libraries from
964 the target system, be it local or remote. This replaces the prefix
965 "remote:". The default sysroot has been changed from "" to
966 "target:". "remote:" is automatically converted to "target:" for
967 backward compatibility.
969 * The system root specified by "set sysroot" will be prepended to the
970 filename of the main executable (if reported to GDB as absolute by
971 the operating system) when starting processes remotely, and when
972 attaching to already-running local or remote processes.
974 * GDB now supports automatic location and retrieval of executable
975 files from remote targets. Remote debugging can now be initiated
976 using only a "target remote" or "target extended-remote" command
977 (no "set sysroot" or "file" commands are required). See "New remote
980 * The "dump" command now supports verilog hex format.
982 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
984 * On GNU/Linux, GDB and gdbserver are now able to access executable
985 and shared library files without a "set sysroot" command when
986 attaching to processes running in different mount namespaces from
987 the debugger. This makes it possible to attach to processes in
988 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
989 See "New remote packets" below.
991 * The "tui reg" command now provides completion for all of the
992 available register groups, including target specific groups.
994 * The HISTSIZE environment variable is no longer read when determining
995 the size of GDB's command history. GDB now instead reads the dedicated
996 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
997 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1002 ** Memory ports can now be unbuffered.
1006 ** gdb.Objfile objects have a new attribute "username",
1007 which is the name of the objfile as specified by the user,
1008 without, for example, resolving symlinks.
1009 ** You can now write frame unwinders in Python.
1010 ** gdb.Type objects have a new method "optimized_out",
1011 returning optimized out gdb.Value instance of this type.
1012 ** gdb.Value objects have new methods "reference_value" and
1013 "const_value" which return a reference to the value and a
1014 "const" version of the value respectively.
1018 maint print symbol-cache
1019 Print the contents of the symbol cache.
1021 maint print symbol-cache-statistics
1022 Print statistics of symbol cache usage.
1024 maint flush-symbol-cache
1025 Flush the contents of the symbol cache.
1029 Start branch trace recording using Branch Trace Store (BTS) format.
1032 Evaluate expression by using the compiler and print result.
1036 Explicit commands for enabling and disabling tui mode.
1039 set mpx bound on i386 and amd64
1040 Support for bound table investigation on Intel MPX enabled applications.
1044 Start branch trace recording using Intel Processor Trace format.
1047 Print information about branch tracing internals.
1049 maint btrace packet-history
1050 Print the raw branch tracing data.
1052 maint btrace clear-packet-history
1053 Discard the stored raw branch tracing data.
1056 Discard all branch tracing data. It will be fetched and processed
1057 anew by the next "record" command.
1062 Renamed from "set debug dwarf2-die".
1063 show debug dwarf-die
1064 Renamed from "show debug dwarf2-die".
1066 set debug dwarf-read
1067 Renamed from "set debug dwarf2-read".
1068 show debug dwarf-read
1069 Renamed from "show debug dwarf2-read".
1071 maint set dwarf always-disassemble
1072 Renamed from "maint set dwarf2 always-disassemble".
1073 maint show dwarf always-disassemble
1074 Renamed from "maint show dwarf2 always-disassemble".
1076 maint set dwarf max-cache-age
1077 Renamed from "maint set dwarf2 max-cache-age".
1078 maint show dwarf max-cache-age
1079 Renamed from "maint show dwarf2 max-cache-age".
1081 set debug dwarf-line
1082 show debug dwarf-line
1083 Control display of debugging info regarding DWARF line processing.
1086 show max-completions
1087 Set the maximum number of candidates to be considered during
1088 completion. The default value is 200. This limit allows GDB
1089 to avoid generating large completion lists, the computation of
1090 which can cause the debugger to become temporarily unresponsive.
1092 set history remove-duplicates
1093 show history remove-duplicates
1094 Control the removal of duplicate history entries.
1096 maint set symbol-cache-size
1097 maint show symbol-cache-size
1098 Control the size of the symbol cache.
1100 set|show record btrace bts buffer-size
1101 Set and show the size of the ring buffer used for branch tracing in
1103 The obtained size may differ from the requested size. Use "info
1104 record" to see the obtained buffer size.
1106 set debug linux-namespaces
1107 show debug linux-namespaces
1108 Control display of debugging info regarding Linux namespaces.
1110 set|show record btrace pt buffer-size
1111 Set and show the size of the ring buffer used for branch tracing in
1112 Intel Processor Trace format.
1113 The obtained size may differ from the requested size. Use "info
1114 record" to see the obtained buffer size.
1116 maint set|show btrace pt skip-pad
1117 Set and show whether PAD packets are skipped when computing the
1120 * The command 'thread apply all' can now support new option '-ascending'
1121 to call its specified command for all threads in ascending order.
1123 * Python/Guile scripting
1125 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1126 special section named `.debug_gdb_scripts'.
1128 * New remote packets
1130 qXfer:btrace-conf:read
1131 Return the branch trace configuration for the current thread.
1133 Qbtrace-conf:bts:size
1134 Set the requested ring buffer size for branch tracing in BTS format.
1137 Enable Intel Procesor Trace-based branch tracing for the current
1138 process. The remote stub reports support for this packet to GDB's
1141 Qbtrace-conf:pt:size
1142 Set the requested ring buffer size for branch tracing in Intel Processor
1146 Indicates a memory breakpoint instruction was executed, irrespective
1147 of whether it was GDB that planted the breakpoint or the breakpoint
1148 is hardcoded in the program. This is required for correct non-stop
1152 Indicates the target stopped for a hardware breakpoint. This is
1153 required for correct non-stop mode operation.
1156 Return information about files on the remote system.
1158 qXfer:exec-file:read
1159 Return the full absolute name of the file that was executed to
1160 create a process running on the remote system.
1163 Select the filesystem on which vFile: operations with filename
1164 arguments will operate. This is required for GDB to be able to
1165 access files on remote targets where the remote stub does not
1166 share a common filesystem with the inferior(s).
1169 Indicates that a fork system call was executed.
1172 Indicates that a vfork system call was executed.
1174 vforkdone stop reason
1175 Indicates that a vfork child of the specified process has executed
1176 an exec or exit, allowing the vfork parent to resume execution.
1178 fork-events and vfork-events features in qSupported
1179 The qSupported packet allows GDB to request support for fork and
1180 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1181 and the qSupported response can contain the corresponding
1182 'stubfeatures'. Set and show commands can be used to display
1183 whether these features are enabled.
1185 * Extended-remote fork events
1187 ** GDB now has support for fork events on extended-remote Linux
1188 targets. For targets with Linux kernels 2.5.60 and later, this
1189 enables follow-fork-mode and detach-on-fork for both fork and
1190 vfork, as well as fork and vfork catchpoints.
1192 * The info record command now shows the recording format and the
1193 branch tracing configuration for the current thread when using
1194 the btrace record target.
1195 For the BTS format, it shows the ring buffer size.
1197 * GDB now has support for DTrace USDT (Userland Static Defined
1198 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1200 * GDB now supports access to vector registers on S/390 GNU/Linux
1203 * Removed command line options
1205 -xdb HP-UX XDB compatibility mode.
1207 * Removed targets and native configurations
1209 HP/PA running HP-UX hppa*-*-hpux*
1210 Itanium running HP-UX ia64-*-hpux*
1212 * New configure options
1215 This configure option allows the user to build GDB with support for
1216 Intel Processor Trace (default: auto). This requires libipt.
1218 --with-libipt-prefix=PATH
1219 Specify the path to the version of libipt that GDB should use.
1220 $PATH/include should contain the intel-pt.h header and
1221 $PATH/lib should contain the libipt.so library.
1223 *** Changes in GDB 7.9.1
1227 ** Xmethods can now specify a result type.
1229 *** Changes in GDB 7.9
1231 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1235 ** You can now access frame registers from Python scripts.
1236 ** New attribute 'producer' for gdb.Symtab objects.
1237 ** gdb.Objfile objects have a new attribute "progspace",
1238 which is the gdb.Progspace object of the containing program space.
1239 ** gdb.Objfile objects have a new attribute "owner".
1240 ** gdb.Objfile objects have a new attribute "build_id",
1241 which is the build ID generated when the file was built.
1242 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1243 ** A new event "gdb.clear_objfiles" has been added, triggered when
1244 selecting a new file to debug.
1245 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1246 ** New function gdb.lookup_objfile.
1248 New events which are triggered when GDB modifies the state of the
1251 ** gdb.events.inferior_call_pre: Function call is about to be made.
1252 ** gdb.events.inferior_call_post: Function call has just been made.
1253 ** gdb.events.memory_changed: A memory location has been altered.
1254 ** gdb.events.register_changed: A register has been altered.
1256 * New Python-based convenience functions:
1258 ** $_caller_is(name [, number_of_frames])
1259 ** $_caller_matches(regexp [, number_of_frames])
1260 ** $_any_caller_is(name [, number_of_frames])
1261 ** $_any_caller_matches(regexp [, number_of_frames])
1263 * GDB now supports the compilation and injection of source code into
1264 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1265 to compile the source code to object code, and if successful, inject
1266 and execute that code within the current context of the inferior.
1267 Currently the C language is supported. The commands used to
1268 interface with this new feature are:
1270 compile code [-raw|-r] [--] [source code]
1271 compile file [-raw|-r] filename
1275 demangle [-l language] [--] name
1276 Demangle "name" in the specified language, or the current language
1277 if elided. This command is renamed from the "maint demangle" command.
1278 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1279 as "maint demangler-warning".
1281 queue-signal signal-name-or-number
1282 Queue a signal to be delivered to the thread when it is resumed.
1284 add-auto-load-scripts-directory directory
1285 Add entries to the list of directories from which to load auto-loaded
1288 maint print user-registers
1289 List all currently available "user" registers.
1291 compile code [-r|-raw] [--] [source code]
1292 Compile, inject, and execute in the inferior the executable object
1293 code produced by compiling the provided source code.
1295 compile file [-r|-raw] filename
1296 Compile and inject into the inferior the executable object code
1297 produced by compiling the source code stored in the filename
1300 * On resume, GDB now always passes the signal the program had stopped
1301 for to the thread the signal was sent to, even if the user changed
1302 threads before resuming. Previously GDB would often (but not
1303 always) deliver the signal to the thread that happens to be current
1306 * Conversely, the "signal" command now consistently delivers the
1307 requested signal to the current thread. GDB now asks for
1308 confirmation if the program had stopped for a signal and the user
1309 switched threads meanwhile.
1311 * "breakpoint always-inserted" modes "off" and "auto" merged.
1313 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1314 won't remove breakpoints from the target until all threads stop,
1315 even in non-stop mode. The "auto" mode has been removed, and "off"
1316 is now the default mode.
1320 set debug symbol-lookup
1321 show debug symbol-lookup
1322 Control display of debugging info regarding symbol lookup.
1326 ** The -list-thread-groups command outputs an exit-code field for
1327 inferiors that have exited.
1331 MIPS SDE mips*-sde*-elf*
1335 Support for these obsolete configurations has been removed.
1337 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1338 SGI Irix-5.x mips-*-irix5*
1339 SGI Irix-6.x mips-*-irix6*
1340 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1341 VAX running Ultrix vax-*-ultrix*
1343 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1344 and "assf"), have been removed. Use the "sharedlibrary" command, or
1345 its alias "share", instead.
1347 *** Changes in GDB 7.8
1349 * New command line options
1352 This is an alias for the --data-directory option.
1354 * GDB supports printing and modifying of variable length automatic arrays
1355 as specified in ISO C99.
1357 * The ARM simulator now supports instruction level tracing
1358 with or without disassembly.
1362 GDB now has support for scripting using Guile. Whether this is
1363 available is determined at configure time.
1364 Guile version 2.0 or greater is required.
1365 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1367 * New commands (for set/show, see "New options" below)
1371 Invoke CODE by passing it to the Guile interpreter.
1375 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1377 info auto-load guile-scripts [regexp]
1378 Print the list of automatically loaded Guile scripts.
1380 * The source command is now capable of sourcing Guile scripts.
1381 This feature is dependent on the debugger being built with Guile support.
1385 set print symbol-loading (off|brief|full)
1386 show print symbol-loading
1387 Control whether to print informational messages when loading symbol
1388 information for a file. The default is "full", but when debugging
1389 programs with large numbers of shared libraries the amount of output
1390 becomes less useful.
1392 set guile print-stack (none|message|full)
1393 show guile print-stack
1394 Show a stack trace when an error is encountered in a Guile script.
1396 set auto-load guile-scripts (on|off)
1397 show auto-load guile-scripts
1398 Control auto-loading of Guile script files.
1400 maint ada set ignore-descriptive-types (on|off)
1401 maint ada show ignore-descriptive-types
1402 Control whether the debugger should ignore descriptive types in Ada
1403 programs. The default is not to ignore the descriptive types. See
1404 the user manual for more details on descriptive types and the intended
1405 usage of this option.
1407 set auto-connect-native-target
1409 Control whether GDB is allowed to automatically connect to the
1410 native target for the run, attach, etc. commands when not connected
1411 to any target yet. See also "target native" below.
1413 set record btrace replay-memory-access (read-only|read-write)
1414 show record btrace replay-memory-access
1415 Control what memory accesses are allowed during replay.
1417 maint set target-async (on|off)
1418 maint show target-async
1419 This controls whether GDB targets operate in synchronous or
1420 asynchronous mode. Normally the default is asynchronous, if it is
1421 available; but this can be changed to more easily debug problems
1422 occurring only in synchronous mode.
1424 set mi-async (on|off)
1426 Control whether MI asynchronous mode is preferred. This supersedes
1427 "set target-async" of previous GDB versions.
1429 * "set target-async" is deprecated as a CLI option and is now an alias
1430 for "set mi-async" (only puts MI into async mode).
1432 * Background execution commands (e.g., "c&", "s&", etc.) are now
1433 possible ``out of the box'' if the target supports them. Previously
1434 the user would need to explicitly enable the possibility with the
1435 "set target-async on" command.
1437 * New features in the GDB remote stub, GDBserver
1439 ** New option --debug-format=option1[,option2,...] allows one to add
1440 additional text to each output. At present only timestamps
1441 are supported: --debug-format=timestamps.
1442 Timestamps can also be turned on with the
1443 "monitor set debug-format timestamps" command from GDB.
1445 * The 'record instruction-history' command now starts counting instructions
1446 at one. This also affects the instruction ranges reported by the
1447 'record function-call-history' command when given the /i modifier.
1449 * The command 'record function-call-history' supports a new modifier '/c' to
1450 indent the function names based on their call stack depth.
1451 The fields for the '/i' and '/l' modifier have been reordered.
1452 The source line range is now prefixed with 'at'.
1453 The instruction range is now prefixed with 'inst'.
1454 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1455 "record instruction-history" and "list" commands.
1457 * The ranges given as arguments to the 'record function-call-history' and
1458 'record instruction-history' commands are now inclusive.
1460 * The btrace record target now supports the 'record goto' command.
1461 For locations inside the execution trace, the back trace is computed
1462 based on the information stored in the execution trace.
1464 * The btrace record target supports limited reverse execution and replay.
1465 The target does not record data and therefore does not allow reading
1466 memory or registers.
1468 * The "catch syscall" command now works on s390*-linux* targets.
1470 * The "compare-sections" command is no longer specific to target
1471 remote. It now works with all targets.
1473 * All native targets are now consistently called "native".
1474 Consequently, the "target child", "target GNU", "target djgpp",
1475 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1476 commands have been replaced with "target native". The QNX/NTO port
1477 leaves the "procfs" target in place and adds a "native" target for
1478 consistency with other ports. The impact on users should be minimal
1479 as these commands previously either throwed an error, or were
1480 no-ops. The target's name is visible in the output of the following
1481 commands: "help target", "info target", "info files", "maint print
1484 * The "target native" command now connects to the native target. This
1485 can be used to launch native programs even when "set
1486 auto-connect-native-target" is set to off.
1488 * GDB now supports access to Intel MPX registers on GNU/Linux.
1490 * Support for Intel AVX-512 registers on GNU/Linux.
1491 Support displaying and modifying Intel AVX-512 registers
1492 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1494 * New remote packets
1496 qXfer:btrace:read's annex
1497 The qXfer:btrace:read packet supports a new annex 'delta' to read
1498 branch trace incrementally.
1502 ** Valid Python operations on gdb.Value objects representing
1503 structs/classes invoke the corresponding overloaded operators if
1505 ** New `Xmethods' feature in the Python API. Xmethods are
1506 additional methods or replacements for existing methods of a C++
1507 class. This feature is useful for those cases where a method
1508 defined in C++ source code could be inlined or optimized out by
1509 the compiler, making it unavailable to GDB.
1512 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1514 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1515 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1516 its alias "share", instead.
1518 * The commands "set remotebaud" and "show remotebaud" are no longer
1519 supported. Use "set serial baud" and "show serial baud" (respectively)
1524 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1525 target-async". The latter is left as a deprecated alias of the
1526 former for backward compatibility. If the target supports it,
1527 CLI background execution commands are now always possible by
1528 default, independently of whether the frontend stated a
1529 preference for asynchronous execution with "-gdb-set mi-async".
1530 Previously "-gdb-set target-async off" affected both MI execution
1531 commands and CLI execution commands.
1533 *** Changes in GDB 7.7
1535 * Improved support for process record-replay and reverse debugging on
1536 arm*-linux* targets. Support for thumb32 and syscall instruction
1537 recording has been added.
1539 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1541 * GDB now supports Fission DWP file format version 2.
1542 http://gcc.gnu.org/wiki/DebugFission
1544 * New convenience function "$_isvoid", to check whether an expression
1545 is void. A void expression is an expression where the type of the
1546 result is "void". For example, some convenience variables may be
1547 "void" when evaluated (e.g., "$_exitcode" before the execution of
1548 the program being debugged; or an undefined convenience variable).
1549 Another example, when calling a function whose return type is
1552 * The "maintenance print objfiles" command now takes an optional regexp.
1554 * The "catch syscall" command now works on arm*-linux* targets.
1556 * GDB now consistently shows "<not saved>" when printing values of
1557 registers the debug info indicates have not been saved in the frame
1558 and there's nowhere to retrieve them from
1559 (callee-saved/call-clobbered registers):
1564 (gdb) info registers rax
1567 Before, the former would print "<optimized out>", and the latter
1568 "*value not available*".
1570 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1575 ** Frame filters and frame decorators have been added.
1576 ** Temporary breakpoints are now supported.
1577 ** Line tables representation has been added.
1578 ** New attribute 'parent_type' for gdb.Field objects.
1579 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1580 ** New attribute 'name' for gdb.Type objects.
1584 Nios II ELF nios2*-*-elf
1585 Nios II GNU/Linux nios2*-*-linux
1586 Texas Instruments MSP430 msp430*-*-elf
1588 * Removed native configurations
1590 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1591 been removed. ELF variants of these configurations are kept supported.
1593 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1594 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1595 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1596 i[34567]86-*-openbsd3.[0-3]
1597 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1598 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1599 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1603 Like "catch throw", but catches a re-thrown exception.
1604 maint check-psymtabs
1605 Renamed from old "maint check-symtabs".
1607 Perform consistency checks on symtabs.
1608 maint expand-symtabs
1609 Expand symtabs matching an optional regexp.
1612 Display the details of GDB configure-time options.
1614 maint set|show per-command
1615 maint set|show per-command space
1616 maint set|show per-command time
1617 maint set|show per-command symtab
1618 Enable display of per-command gdb resource usage.
1620 remove-symbol-file FILENAME
1621 remove-symbol-file -a ADDRESS
1622 Remove a symbol file added via add-symbol-file. The file to remove
1623 can be identified by its filename or by an address that lies within
1624 the boundaries of this symbol file in memory.
1627 info exceptions REGEXP
1628 Display the list of Ada exceptions defined in the program being
1629 debugged. If provided, only the exceptions whose names match REGEXP
1634 set debug symfile off|on
1636 Control display of debugging info regarding reading symbol files and
1637 symbol tables within those files
1639 set print raw frame-arguments
1640 show print raw frame-arguments
1641 Set/show whether to print frame arguments in raw mode,
1642 disregarding any defined pretty-printers.
1644 set remote trace-status-packet
1645 show remote trace-status-packet
1646 Set/show the use of remote protocol qTStatus packet.
1650 Control display of debugging messages related to Nios II targets.
1654 Control whether target-assisted range stepping is enabled.
1656 set startup-with-shell
1657 show startup-with-shell
1658 Specifies whether Unix child processes are started via a shell or
1663 Use the target memory cache for accesses to the code segment. This
1664 improves performance of remote debugging (particularly disassembly).
1666 * You can now use a literal value 'unlimited' for options that
1667 interpret 0 or -1 as meaning "unlimited". E.g., "set
1668 trace-buffer-size unlimited" is now an alias for "set
1669 trace-buffer-size -1" and "set height unlimited" is now an alias for
1672 * The "set debug symtab-create" debugging option of GDB has been changed to
1673 accept a verbosity level. 0 means "off", 1 provides basic debugging
1674 output, and values of 2 or greater provides more verbose output.
1676 * New command-line options
1678 Display the details of GDB configure-time options.
1680 * The command 'tsave' can now support new option '-ctf' to save trace
1681 buffer in Common Trace Format.
1683 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1686 * GDB now implements the the C++ 'typeid' operator.
1688 * The new convenience variable $_exception holds the exception being
1689 thrown or caught at an exception-related catchpoint.
1691 * The exception-related catchpoints, like "catch throw", now accept a
1692 regular expression which can be used to filter exceptions by type.
1694 * The new convenience variable $_exitsignal is automatically set to
1695 the terminating signal number when the program being debugged dies
1696 due to an uncaught signal.
1700 ** All MI commands now accept an optional "--language" option.
1701 Support for this feature can be verified by using the "-list-features"
1702 command, which should contain "language-option".
1704 ** The new command -info-gdb-mi-command allows the user to determine
1705 whether a GDB/MI command is supported or not.
1707 ** The "^error" result record returned when trying to execute an undefined
1708 GDB/MI command now provides a variable named "code" whose content is the
1709 "undefined-command" error code. Support for this feature can be verified
1710 by using the "-list-features" command, which should contain
1711 "undefined-command-error-code".
1713 ** The -trace-save MI command can optionally save trace buffer in Common
1716 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1718 ** The command -data-list-register-values now accepts an optional
1719 "--skip-unavailable" option. When used, only the available registers
1722 ** The new command -trace-frame-collected dumps collected variables,
1723 computed expressions, tvars, memory and registers in a traceframe.
1725 ** The commands -stack-list-locals, -stack-list-arguments and
1726 -stack-list-variables now accept an option "--skip-unavailable".
1727 When used, only the available locals or arguments are displayed.
1729 ** The -exec-run command now accepts an optional "--start" option.
1730 When used, the command follows the same semantics as the "start"
1731 command, stopping the program's execution at the start of its
1732 main subprogram. Support for this feature can be verified using
1733 the "-list-features" command, which should contain
1734 "exec-run-start-option".
1736 ** The new commands -catch-assert and -catch-exceptions insert
1737 catchpoints stopping the program when Ada exceptions are raised.
1739 ** The new command -info-ada-exceptions provides the equivalent of
1740 the new "info exceptions" command.
1742 * New system-wide configuration scripts
1743 A GDB installation now provides scripts suitable for use as system-wide
1744 configuration scripts for the following systems:
1748 * GDB now supports target-assigned range stepping with remote targets.
1749 This improves the performance of stepping source lines by reducing
1750 the number of control packets from/to GDB. See "New remote packets"
1753 * GDB now understands the element 'tvar' in the XML traceframe info.
1754 It has the id of the collected trace state variables.
1756 * On S/390 targets that provide the transactional-execution feature,
1757 the program interruption transaction diagnostic block (TDB) is now
1758 represented as a number of additional "registers" in GDB.
1760 * New remote packets
1764 The vCont packet supports a new 'r' action, that tells the remote
1765 stub to step through an address range itself, without GDB
1766 involvemement at each single-step.
1768 qXfer:libraries-svr4:read's annex
1769 The previously unused annex of the qXfer:libraries-svr4:read packet
1770 is now used to support passing an argument list. The remote stub
1771 reports support for this argument list to GDB's qSupported query.
1772 The defined arguments are "start" and "prev", used to reduce work
1773 necessary for library list updating, resulting in significant
1776 * New features in the GDB remote stub, GDBserver
1778 ** GDBserver now supports target-assisted range stepping. Currently
1779 enabled on x86/x86_64 GNU/Linux targets.
1781 ** GDBserver now adds element 'tvar' in the XML in the reply to
1782 'qXfer:traceframe-info:read'. It has the id of the collected
1783 trace state variables.
1785 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1788 * New 'z' formatter for printing and examining memory, this displays the
1789 value as hexadecimal zero padded on the left to the size of the type.
1791 * GDB can now use Windows x64 unwinding data.
1793 * The "set remotebaud" command has been replaced by "set serial baud".
1794 Similarly, "show remotebaud" has been replaced by "show serial baud".
1795 The "set remotebaud" and "show remotebaud" commands are still available
1796 to provide backward compatibility with older versions of GDB.
1798 *** Changes in GDB 7.6
1800 * Target record has been renamed to record-full.
1801 Record/replay is now enabled with the "record full" command.
1802 This also affects settings that are associated with full record/replay
1803 that have been moved from "set/show record" to "set/show record full":
1805 set|show record full insn-number-max
1806 set|show record full stop-at-limit
1807 set|show record full memory-query
1809 * A new record target "record-btrace" has been added. The new target
1810 uses hardware support to record the control-flow of a process. It
1811 does not support replaying the execution, but it implements the
1812 below new commands for investigating the recorded execution log.
1813 This new recording method can be enabled using:
1817 The "record-btrace" target is only available on Intel Atom processors
1818 and requires a Linux kernel 2.6.32 or later.
1820 * Two new commands have been added for record/replay to give information
1821 about the recorded execution without having to replay the execution.
1822 The commands are only supported by "record btrace".
1824 record instruction-history prints the execution history at
1825 instruction granularity
1827 record function-call-history prints the execution history at
1828 function granularity
1830 * New native configurations
1832 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1833 FreeBSD/powerpc powerpc*-*-freebsd
1834 x86_64/Cygwin x86_64-*-cygwin*
1835 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1839 ARM AArch64 aarch64*-*-elf
1840 ARM AArch64 GNU/Linux aarch64*-*-linux
1841 Lynx 178 PowerPC powerpc-*-lynx*178
1842 x86_64/Cygwin x86_64-*-cygwin*
1843 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1845 * If the configured location of system.gdbinit file (as given by the
1846 --with-system-gdbinit option at configure time) is in the
1847 data-directory (as specified by --with-gdb-datadir at configure
1848 time) or in one of its subdirectories, then GDB will look for the
1849 system-wide init file in the directory specified by the
1850 --data-directory command-line option.
1852 * New command line options:
1854 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1855 other initialization files, unlike -nx which disables all of them.
1857 * Removed command line options
1859 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1862 * The 'ptype' and 'whatis' commands now accept an argument to control
1865 * 'info proc' now works on some core files.
1869 ** Vectors can be created with gdb.Type.vector.
1871 ** Python's atexit.register now works in GDB.
1873 ** Types can be pretty-printed via a Python API.
1875 ** Python 3 is now supported (in addition to Python 2.4 or later)
1877 ** New class gdb.Architecture exposes GDB's internal representation
1878 of architecture in the Python API.
1880 ** New method Frame.architecture returns the gdb.Architecture object
1881 corresponding to the frame's architecture.
1883 * New Python-based convenience functions:
1885 ** $_memeq(buf1, buf2, length)
1886 ** $_streq(str1, str2)
1888 ** $_regex(str, regex)
1890 * The 'cd' command now defaults to using '~' (the home directory) if not
1893 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1894 default for GCC since November 2000.
1896 * The command 'forward-search' can now be abbreviated as 'fo'.
1898 * The command 'info tracepoints' can now display 'installed on target'
1899 or 'not installed on target' for each non-pending location of tracepoint.
1901 * New configure options
1903 --enable-libmcheck/--disable-libmcheck
1904 By default, development versions are built with -lmcheck on hosts
1905 that support it, in order to help track memory corruption issues.
1906 Release versions, on the other hand, are built without -lmcheck
1907 by default. The --enable-libmcheck/--disable-libmcheck configure
1908 options allow the user to override that default.
1909 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1910 This configure option allows the user to build GDB with
1911 libbabeltrace using which GDB can read Common Trace Format data.
1913 * New commands (for set/show, see "New options" below)
1916 Catch signals. This is similar to "handle", but allows commands and
1917 conditions to be attached.
1920 List the BFDs known to GDB.
1922 python-interactive [command]
1924 Start a Python interactive prompt, or evaluate the optional command
1925 and print the result of expressions.
1928 "py" is a new alias for "python".
1930 enable type-printer [name]...
1931 disable type-printer [name]...
1932 Enable or disable type printers.
1936 ** For the Renesas Super-H architecture, the "regs" command has been removed
1937 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1942 set print type methods (on|off)
1943 show print type methods
1944 Control whether method declarations are displayed by "ptype".
1945 The default is to show them.
1947 set print type typedefs (on|off)
1948 show print type typedefs
1949 Control whether typedef definitions are displayed by "ptype".
1950 The default is to show them.
1952 set filename-display basename|relative|absolute
1953 show filename-display
1954 Control the way in which filenames is displayed.
1955 The default is "relative", which preserves previous behavior.
1957 set trace-buffer-size
1958 show trace-buffer-size
1959 Request target to change the size of trace buffer.
1961 set remote trace-buffer-size-packet auto|on|off
1962 show remote trace-buffer-size-packet
1963 Control the use of the remote protocol `QTBuffer:size' packet.
1967 Control display of debugging messages related to ARM AArch64.
1970 set debug coff-pe-read
1971 show debug coff-pe-read
1972 Control display of debugging messages related to reading of COFF/PE
1977 Control display of debugging messages related to Mach-O symbols
1980 set debug notification
1981 show debug notification
1982 Control display of debugging info for async remote notification.
1986 ** Command parameter changes are now notified using new async record
1987 "=cmd-param-changed".
1988 ** Trace frame changes caused by command "tfind" are now notified using
1989 new async record "=traceframe-changed".
1990 ** The creation, deletion and modification of trace state variables
1991 are now notified using new async records "=tsv-created",
1992 "=tsv-deleted" and "=tsv-modified".
1993 ** The start and stop of process record are now notified using new
1994 async record "=record-started" and "=record-stopped".
1995 ** Memory changes are now notified using new async record
1997 ** The data-disassemble command response will include a "fullname" field
1998 containing the absolute file name when source has been requested.
1999 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2000 command, to allow pattern filling of memory areas.
2001 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2002 library load/unload events.
2003 ** The response to breakpoint commands and breakpoint async records
2004 includes an "installed" field containing a boolean state about each
2005 non-pending tracepoint location is whether installed on target or not.
2006 ** Output of the "-trace-status" command includes a "trace-file" field
2007 containing the name of the trace file being examined. This field is
2008 optional, and only present when examining a trace file.
2009 ** The "fullname" field is now always present along with the "file" field,
2010 even if the file cannot be found by GDB.
2012 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2013 You must have the LZMA library available when configuring GDB for this
2014 feature to be enabled. For more information, see:
2015 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2017 * New remote packets
2020 Set the size of trace buffer. The remote stub reports support for this
2021 packet to gdb's qSupported query.
2024 Enable Branch Trace Store (BTS)-based branch tracing for the current
2025 thread. The remote stub reports support for this packet to gdb's
2029 Disable branch tracing for the current thread. The remote stub reports
2030 support for this packet to gdb's qSupported query.
2033 Read the traced branches for the current thread. The remote stub
2034 reports support for this packet to gdb's qSupported query.
2036 *** Changes in GDB 7.5
2038 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2039 for more x32 ABI info.
2041 * GDB now supports access to MIPS DSP registers on Linux targets.
2043 * GDB now supports debugging microMIPS binaries.
2045 * The "info os" command on GNU/Linux can now display information on
2046 several new classes of objects managed by the operating system:
2047 "info os procgroups" lists process groups
2048 "info os files" lists file descriptors
2049 "info os sockets" lists internet-domain sockets
2050 "info os shm" lists shared-memory regions
2051 "info os semaphores" lists semaphores
2052 "info os msg" lists message queues
2053 "info os modules" lists loaded kernel modules
2055 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2056 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2057 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2058 options and inspect the probe arguments using the new $_probe_arg family
2059 of convenience variables. You can obtain more information about SystemTap
2060 in <http://sourceware.org/systemtap/>.
2062 * GDB now supports reversible debugging on ARM, it allows you to
2063 debug basic ARM and THUMB instructions, and provides
2064 record/replay support.
2066 * The option "symbol-reloading" has been deleted as it is no longer used.
2070 ** GDB commands implemented in Python can now be put in command class
2073 ** The "maint set python print-stack on|off" is now deleted.
2075 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2076 apply "flag enum"-style pretty-printing to any enum.
2078 ** gdb.lookup_symbol can now work when there is no current frame.
2080 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2081 the source at which the symbol was defined.
2083 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2084 method 'value'. The former indicates whether the symbol needs a
2085 frame in order to compute its value, and the latter computes the
2088 ** A new method 'referenced_value' on gdb.Value objects which can
2089 dereference pointer as well as C++ reference values.
2091 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2092 which return the global and static blocks (as gdb.Block objects),
2093 of the underlying symbol table, respectively.
2095 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2096 object associated with a PC value.
2098 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2099 of the address range occupied by code for the current source line.
2101 * Go language support.
2102 GDB now supports debugging programs written in the Go programming
2105 * GDBserver now supports stdio connections.
2106 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2108 * The binary "gdbtui" can no longer be built or installed.
2109 Use "gdb -tui" instead.
2111 * GDB will now print "flag" enums specially. A flag enum is one where
2112 all the enumerator values have no bits in common when pairwise
2113 "and"ed. When printing a value whose type is a flag enum, GDB will
2114 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2115 (gdb) print (enum E) 3
2118 * The filename part of a linespec will now match trailing components
2119 of a source file name. For example, "break gcc/expr.c:1000" will
2120 now set a breakpoint in build/gcc/expr.c, but not
2121 build/libcpp/expr.c.
2123 * The "info proc" and "generate-core-file" commands will now also
2124 work on remote targets connected to GDBserver on Linux.
2126 * The command "info catch" has been removed. It has been disabled
2127 since December 2007.
2129 * The "catch exception" and "catch assert" commands now accept
2130 a condition at the end of the command, much like the "break"
2131 command does. For instance:
2133 (gdb) catch exception Constraint_Error if Barrier = True
2135 Previously, it was possible to add a condition to such catchpoints,
2136 but it had to be done as a second step, after the catchpoint had been
2137 created, using the "condition" command.
2139 * The "info static-tracepoint-marker" command will now also work on
2140 native Linux targets with in-process agent.
2142 * GDB can now set breakpoints on inlined functions.
2144 * The .gdb_index section has been updated to include symbols for
2145 inlined functions. GDB will ignore older .gdb_index sections by
2146 default, which could cause symbol files to be loaded more slowly
2147 until their .gdb_index sections can be recreated. The new command
2148 "set use-deprecated-index-sections on" will cause GDB to use any older
2149 .gdb_index sections it finds. This will restore performance, but the
2150 ability to set breakpoints on inlined functions will be lost in symbol
2151 files with older .gdb_index sections.
2153 The .gdb_index section has also been updated to record more information
2154 about each symbol. This speeds up the "info variables", "info functions"
2155 and "info types" commands when used with programs having the .gdb_index
2156 section, as well as speeding up debugging with shared libraries using
2157 the .gdb_index section.
2159 * Ada support for GDB/MI Variable Objects has been added.
2161 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2166 ** New command -info-os is the MI equivalent of "info os".
2168 ** Output logs ("set logging" and related) now include MI output.
2172 ** "set use-deprecated-index-sections on|off"
2173 "show use-deprecated-index-sections on|off"
2174 Controls the use of deprecated .gdb_index sections.
2176 ** "catch load" and "catch unload" can be used to stop when a shared
2177 library is loaded or unloaded, respectively.
2179 ** "enable count" can be used to auto-disable a breakpoint after
2182 ** "info vtbl" can be used to show the virtual method tables for
2183 C++ and Java objects.
2185 ** "explore" and its sub commands "explore value" and "explore type"
2186 can be used to recursively explore values and types of
2187 expressions. These commands are available only if GDB is
2188 configured with '--with-python'.
2190 ** "info auto-load" shows status of all kinds of auto-loaded files,
2191 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2192 sequences of commands files, "info auto-load python-scripts"
2193 shows status of auto-loading Python script files,
2194 "info auto-load local-gdbinit" shows status of loading init file
2195 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2196 status of inferior specific thread debugging shared library loading.
2198 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2199 and "show auto-load-scripts" commands have been deprecated, use their
2200 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2201 and "show auto-load python-scripts" counterparts instead.
2203 ** "dprintf location,format,args..." creates a dynamic printf, which
2204 is basically a breakpoint that does a printf and immediately
2205 resumes your program's execution, so it is like a printf that you
2206 can insert dynamically at runtime instead of at compiletime.
2208 ** "set print symbol"
2210 Controls whether GDB attempts to display the symbol, if any,
2211 corresponding to addresses it prints. This defaults to "on", but
2212 you can set it to "off" to restore GDB's previous behavior.
2214 * Deprecated commands
2216 ** For the Renesas Super-H architecture, the "regs" command has been
2217 deprecated, and "info all-registers" should be used instead.
2221 Renesas RL78 rl78-*-elf
2222 HP OpenVMS ia64 ia64-hp-openvms*
2224 * GDBserver supports evaluation of breakpoint conditions. When
2225 support is advertised by GDBserver, GDB may be told to send the
2226 breakpoint conditions in bytecode form to GDBserver. GDBserver
2227 will only report the breakpoint trigger to GDB when its condition
2232 set mips compression
2233 show mips compression
2234 Select the compressed ISA encoding used in functions that have no symbol
2235 information available. The encoding can be set to either of:
2238 and is updated automatically from ELF file flags if available.
2240 set breakpoint condition-evaluation
2241 show breakpoint condition-evaluation
2242 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2243 GDBserver ("target"). Default option "auto" chooses the most efficient
2245 This option can improve debugger efficiency depending on the speed of the
2249 Disable auto-loading globally.
2252 Show auto-loading setting of all kinds of auto-loaded files.
2254 set auto-load gdb-scripts on|off
2255 show auto-load gdb-scripts
2256 Control auto-loading of GDB canned sequences of commands files.
2258 set auto-load python-scripts on|off
2259 show auto-load python-scripts
2260 Control auto-loading of Python script files.
2262 set auto-load local-gdbinit on|off
2263 show auto-load local-gdbinit
2264 Control loading of init file (.gdbinit) from current directory.
2266 set auto-load libthread-db on|off
2267 show auto-load libthread-db
2268 Control auto-loading of inferior specific thread debugging shared library.
2270 set auto-load scripts-directory <dir1>[:<dir2>...]
2271 show auto-load scripts-directory
2272 Set a list of directories from which to load auto-loaded scripts.
2273 Automatically loaded Python scripts and GDB scripts are located in one
2274 of the directories listed by this option.
2275 The delimiter (':' above) may differ according to the host platform.
2277 set auto-load safe-path <dir1>[:<dir2>...]
2278 show auto-load safe-path
2279 Set a list of directories from which it is safe to auto-load files.
2280 The delimiter (':' above) may differ according to the host platform.
2282 set debug auto-load on|off
2283 show debug auto-load
2284 Control display of debugging info for auto-loading the files above.
2286 set dprintf-style gdb|call|agent
2288 Control the way in which a dynamic printf is performed; "gdb"
2289 requests a GDB printf command, while "call" causes dprintf to call a
2290 function in the inferior. "agent" requests that the target agent
2291 (such as GDBserver) do the printing.
2293 set dprintf-function <expr>
2294 show dprintf-function
2295 set dprintf-channel <expr>
2296 show dprintf-channel
2297 Set the function and optional first argument to the call when using
2298 the "call" style of dynamic printf.
2300 set disconnected-dprintf on|off
2301 show disconnected-dprintf
2302 Control whether agent-style dynamic printfs continue to be in effect
2303 after GDB disconnects.
2305 * New configure options
2307 --with-auto-load-dir
2308 Configure default value for the 'set auto-load scripts-directory'
2309 setting above. It defaults to '$debugdir:$datadir/auto-load',
2310 $debugdir representing global debugging info directories (available
2311 via 'show debug-file-directory') and $datadir representing GDB's data
2312 directory (available via 'show data-directory').
2314 --with-auto-load-safe-path
2315 Configure default value for the 'set auto-load safe-path' setting
2316 above. It defaults to the --with-auto-load-dir setting.
2318 --without-auto-load-safe-path
2319 Set 'set auto-load safe-path' to '/', effectively disabling this
2322 * New remote packets
2324 z0/z1 conditional breakpoints extension
2326 The z0/z1 breakpoint insertion packets have been extended to carry
2327 a list of conditional expressions over to the remote stub depending on the
2328 condition evaluation mode. The use of this extension can be controlled
2329 via the "set remote conditional-breakpoints-packet" command.
2333 Specify the signals which the remote stub may pass to the debugged
2334 program without GDB involvement.
2336 * New command line options
2338 --init-command=FILE, -ix Like --command, -x but execute it
2339 before loading inferior.
2340 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2341 execute it before loading inferior.
2343 *** Changes in GDB 7.4
2345 * GDB now handles ambiguous linespecs more consistently; the existing
2346 FILE:LINE support has been expanded to other types of linespecs. A
2347 breakpoint will now be set on all matching locations in all
2348 inferiors, and locations will be added or removed according to
2351 * GDB now allows you to skip uninteresting functions and files when
2352 stepping with the "skip function" and "skip file" commands.
2354 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2355 and "show remote hardware-watchpoint-length-limit". These allows to
2356 set or show the maximum length limit (in bytes) of a remote
2357 target hardware watchpoint.
2359 This allows e.g. to use "unlimited" hardware watchpoints with the
2360 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2361 watchpoints are slower than real hardware watchpoints but are
2362 significantly faster than gdb software watchpoints.
2366 ** The register_pretty_printer function in module gdb.printing now takes
2367 an optional `replace' argument. If True, the new printer replaces any
2370 ** The "maint set python print-stack on|off" command has been
2371 deprecated and will be deleted in GDB 7.5.
2372 A new command: "set python print-stack none|full|message" has
2373 replaced it. Additionally, the default for "print-stack" is
2374 now "message", which just prints the error message without
2377 ** A prompt substitution hook (prompt_hook) is now available to the
2380 ** A new Python module, gdb.prompt has been added to the GDB Python
2381 modules library. This module provides functionality for
2382 escape sequences in prompts (used by set/show
2383 extended-prompt). These escape sequences are replaced by their
2384 corresponding value.
2386 ** Python commands and convenience-functions located in
2387 'data-directory'/python/gdb/command and
2388 'data-directory'/python/gdb/function are now automatically loaded
2391 ** Blocks now provide four new attributes. global_block and
2392 static_block will return the global and static blocks
2393 respectively. is_static and is_global are boolean attributes
2394 that indicate if the block is one of those two types.
2396 ** Symbols now provide the "type" attribute, the type of the symbol.
2398 ** The "gdb.breakpoint" function has been deprecated in favor of
2401 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2402 of a function. This class is based on the "finish" command
2403 available in the CLI.
2405 ** Type objects for struct and union types now allow access to
2406 the fields using standard Python dictionary (mapping) methods.
2407 For example, "some_type['myfield']" now works, as does
2408 "some_type.items()".
2410 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2413 ** A new function, "deep_items" has been added to the gdb.types
2414 module in the GDB Python modules library. This function returns
2415 an iterator over the fields of a struct or union type. Unlike
2416 the standard Python "iteritems" method, it will recursively traverse
2417 any anonymous fields.
2421 ** "*stopped" events can report several new "reason"s, such as
2424 ** Breakpoint changes are now notified using new async records, like
2425 "=breakpoint-modified".
2427 ** New command -ada-task-info.
2429 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2430 $sdir specifies the default system locations of shared libraries.
2431 $pdir specifies the directory where the libpthread used by the application
2434 GDB no longer looks in $sdir and $pdir after it has searched the directories
2435 mentioned in libthread-db-search-path. If you want to search those
2436 directories, they must be specified in libthread-db-search-path.
2437 The default value of libthread-db-search-path on GNU/Linux and Solaris
2438 systems is now "$sdir:$pdir".
2440 $pdir is not supported by gdbserver, it is currently ignored.
2441 $sdir is supported by gdbserver.
2443 * New configure option --with-iconv-bin.
2444 When using the internationalization support like the one in the GNU C
2445 library, GDB will invoke the "iconv" program to get a list of supported
2446 character sets. If this program lives in a non-standard location, one can
2447 use this option to specify where to find it.
2449 * When natively debugging programs on PowerPC BookE processors running
2450 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2451 watchpoints, which specify a mask in addition to an address to watch.
2452 The mask specifies that some bits of an address (the bits which are
2453 reset in the mask) should be ignored when matching the address accessed
2454 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2455 section in the user manual for more details.
2457 * The new option --once causes GDBserver to stop listening for connections once
2458 the first connection is made. The listening port used by GDBserver will
2459 become available after that.
2461 * New commands "info macros" and "alias" have been added.
2463 * New function parameters suffix @entry specifies value of function parameter
2464 at the time the function got called. Entry values are available only since
2470 "!" is now an alias of the "shell" command.
2471 Note that no space is needed between "!" and SHELL COMMAND.
2475 watch EXPRESSION mask MASK_VALUE
2476 The watch command now supports the mask argument which allows creation
2477 of masked watchpoints, if the current architecture supports this feature.
2479 info auto-load-scripts [REGEXP]
2480 This command was formerly named "maintenance print section-scripts".
2481 It is now generally useful and is no longer a maintenance-only command.
2483 info macro [-all] [--] MACRO
2484 The info macro command has new options `-all' and `--'. The first for
2485 printing all definitions of a macro. The second for explicitly specifying
2486 the end of arguments and the beginning of the macro name in case the macro
2487 name starts with a hyphen.
2489 collect[/s] EXPRESSIONS
2490 The tracepoint collect command now takes an optional modifier "/s"
2491 that directs it to dereference pointer-to-character types and
2492 collect the bytes of memory up to a zero byte. The behavior is
2493 similar to what you see when you use the regular print command on a
2494 string. An optional integer following the "/s" sets a bound on the
2495 number of bytes that will be collected.
2498 The trace start command now interprets any supplied arguments as a
2499 note to be recorded with the trace run, with an effect similar to
2500 setting the variable trace-notes.
2503 The trace stop command now interprets any arguments as a note to be
2504 mentioned along with the tstatus report that the trace was stopped
2505 with a command. The effect is similar to setting the variable
2508 * Tracepoints can now be enabled and disabled at any time after a trace
2509 experiment has been started using the standard "enable" and "disable"
2510 commands. It is now possible to start a trace experiment with no enabled
2511 tracepoints; GDB will display a warning, but will allow the experiment to
2512 begin, assuming that tracepoints will be enabled as needed while the trace
2515 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2516 locations with 4-byte instructions, when they were previously
2517 limited to locations with instructions of 5 bytes or longer.
2521 set debug dwarf2-read
2522 show debug dwarf2-read
2523 Turns on or off display of debugging messages related to reading
2524 DWARF debug info. The default is off.
2526 set debug symtab-create
2527 show debug symtab-create
2528 Turns on or off display of debugging messages related to symbol table
2529 creation. The default is off.
2532 show extended-prompt
2533 Set the GDB prompt, and allow escape sequences to be inserted to
2534 display miscellaneous information (see 'help set extended-prompt'
2535 for the list of sequences). This prompt (and any information
2536 accessed through the escape sequences) is updated every time the
2537 prompt is displayed.
2539 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2540 show print entry-values
2541 Set printing of frame argument values at function entry. In some cases
2542 GDB can determine the value of function argument which was passed by the
2543 function caller, even if the value was modified inside the called function.
2545 set debug entry-values
2546 show debug entry-values
2547 Control display of debugging info for determining frame argument values at
2548 function entry and virtual tail call frames.
2550 set basenames-may-differ
2551 show basenames-may-differ
2552 Set whether a source file may have multiple base names.
2553 (A "base name" is the name of a file with the directory part removed.
2554 Example: The base name of "/home/user/hello.c" is "hello.c".)
2555 If set, GDB will canonicalize file names (e.g., expand symlinks)
2556 before comparing them. Canonicalization is an expensive operation,
2557 but it allows the same file be known by more than one base name.
2558 If not set (the default), all source files are assumed to have just
2559 one base name, and gdb will do file name comparisons more efficiently.
2565 Set a user name and notes for the current and any future trace runs.
2566 This is useful for long-running and/or disconnected traces, to
2567 inform others (or yourself) as to who is running the trace, supply
2568 contact information, or otherwise explain what is going on.
2570 set trace-stop-notes
2571 show trace-stop-notes
2572 Set a note attached to the trace run, that is displayed when the
2573 trace has been stopped by a tstop command. This is useful for
2574 instance as an explanation, if you are stopping a trace run that was
2575 started by someone else.
2577 * New remote packets
2581 Dynamically enable a tracepoint in a started trace experiment.
2585 Dynamically disable a tracepoint in a started trace experiment.
2589 Set the user and notes of the trace run.
2593 Query the current status of a tracepoint.
2597 Query the minimum length of instruction at which a fast tracepoint may
2600 * Dcache size (number of lines) and line-size are now runtime-configurable
2601 via "set dcache line" and "set dcache line-size" commands.
2605 Texas Instruments TMS320C6x tic6x-*-*
2609 Renesas RL78 rl78-*-elf
2611 *** Changes in GDB 7.3.1
2613 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2615 *** Changes in GDB 7.3
2617 * GDB has a new command: "thread find [REGEXP]".
2618 It finds the thread id whose name, target id, or thread extra info
2619 matches the given regular expression.
2621 * The "catch syscall" command now works on mips*-linux* targets.
2623 * The -data-disassemble MI command now supports modes 2 and 3 for
2624 dumping the instruction opcodes.
2626 * New command line options
2628 -data-directory DIR Specify DIR as the "data-directory".
2629 This is mostly for testing purposes.
2631 * The "maint set python auto-load on|off" command has been renamed to
2632 "set auto-load-scripts on|off".
2634 * GDB has a new command: "set directories".
2635 It is like the "dir" command except that it replaces the
2636 source path list instead of augmenting it.
2638 * GDB now understands thread names.
2640 On GNU/Linux, "info threads" will display the thread name as set by
2641 prctl or pthread_setname_np.
2643 There is also a new command, "thread name", which can be used to
2644 assign a name internally for GDB to display.
2647 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2648 has been integrated into GDB.
2652 ** The function gdb.Write now accepts an optional keyword 'stream'.
2653 This keyword, when provided, will direct the output to either
2654 stdout, stderr, or GDB's logging output.
2656 ** Parameters can now be be sub-classed in Python, and in particular
2657 you may implement the get_set_doc and get_show_doc functions.
2658 This improves how Parameter set/show documentation is processed
2659 and allows for more dynamic content.
2661 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2662 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2663 have an is_valid method.
2665 ** Breakpoints can now be sub-classed in Python, and in particular
2666 you may implement a 'stop' function that is executed each time
2667 the inferior reaches that breakpoint.
2669 ** New function gdb.lookup_global_symbol looks up a global symbol.
2671 ** GDB values in Python are now callable if the value represents a
2672 function. For example, if 'some_value' represents a function that
2673 takes two integer parameters and returns a value, you can call
2674 that function like so:
2676 result = some_value (10,20)
2678 ** Module gdb.types has been added.
2679 It contains a collection of utilities for working with gdb.Types objects:
2680 get_basic_type, has_field, make_enum_dict.
2682 ** Module gdb.printing has been added.
2683 It contains utilities for writing and registering pretty-printers.
2684 New classes: PrettyPrinter, SubPrettyPrinter,
2685 RegexpCollectionPrettyPrinter.
2686 New function: register_pretty_printer.
2688 ** New commands "info pretty-printers", "enable pretty-printer" and
2689 "disable pretty-printer" have been added.
2691 ** gdb.parameter("directories") is now available.
2693 ** New function gdb.newest_frame returns the newest frame in the
2696 ** The gdb.InferiorThread class has a new "name" attribute. This
2697 holds the thread's name.
2699 ** Python Support for Inferior events.
2700 Python scripts can add observers to be notified of events
2701 occurring in the process being debugged.
2702 The following events are currently supported:
2703 - gdb.events.cont Continue event.
2704 - gdb.events.exited Inferior exited event.
2705 - gdb.events.stop Signal received, and Breakpoint hit events.
2709 ** GDB now puts template parameters in scope when debugging in an
2710 instantiation. For example, if you have:
2712 template<int X> int func (void) { return X; }
2714 then if you step into func<5>, "print X" will show "5". This
2715 feature requires proper debuginfo support from the compiler; it
2716 was added to GCC 4.5.
2718 ** The motion commands "next", "finish", "until", and "advance" now
2719 work better when exceptions are thrown. In particular, GDB will
2720 no longer lose control of the inferior; instead, the GDB will
2721 stop the inferior at the point at which the exception is caught.
2722 This functionality requires a change in the exception handling
2723 code that was introduced in GCC 4.5.
2725 * GDB now follows GCC's rules on accessing volatile objects when
2726 reading or writing target state during expression evaluation.
2727 One notable difference to prior behavior is that "print x = 0"
2728 no longer generates a read of x; the value of the assignment is
2729 now always taken directly from the value being assigned.
2731 * GDB now has some support for using labels in the program's source in
2732 linespecs. For instance, you can use "advance label" to continue
2733 execution to a label.
2735 * GDB now has support for reading and writing a new .gdb_index
2736 section. This section holds a fast index of DWARF debugging
2737 information and can be used to greatly speed up GDB startup and
2738 operation. See the documentation for `save gdb-index' for details.
2740 * The "watch" command now accepts an optional "-location" argument.
2741 When used, this causes GDB to watch the memory referred to by the
2742 expression. Such a watchpoint is never deleted due to it going out
2745 * GDB now supports thread debugging of core dumps on GNU/Linux.
2747 GDB now activates thread debugging using the libthread_db library
2748 when debugging GNU/Linux core dumps, similarly to when debugging
2749 live processes. As a result, when debugging a core dump file, GDB
2750 is now able to display pthread_t ids of threads. For example, "info
2751 threads" shows the same output as when debugging the process when it
2752 was live. In earlier releases, you'd see something like this:
2755 * 1 LWP 6780 main () at main.c:10
2757 While now you see this:
2760 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2762 It is also now possible to inspect TLS variables when debugging core
2765 When debugging a core dump generated on a machine other than the one
2766 used to run GDB, you may need to point GDB at the correct
2767 libthread_db library with the "set libthread-db-search-path"
2768 command. See the user manual for more details on this command.
2770 * When natively debugging programs on PowerPC BookE processors running
2771 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2772 which stop execution of the inferior whenever it executes an instruction
2773 at any address within the specified range. See the "PowerPC Embedded"
2774 section in the user manual for more details.
2776 * New features in the GDB remote stub, GDBserver
2778 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2779 and i686 LynxOS (version 5.x).
2781 ** GDBserver is now supported on Blackfin Linux.
2783 * New native configurations
2785 ia64 HP-UX ia64-*-hpux*
2789 Analog Devices, Inc. Blackfin Processor bfin-*
2791 * Ada task switching is now supported on sparc-elf targets when
2792 debugging a program using the Ravenscar Profile. For more information,
2793 see the "Tasking Support when using the Ravenscar Profile" section
2794 in the GDB user manual.
2796 * Guile support was removed.
2798 * New features in the GNU simulator
2800 ** The --map-info flag lists all known core mappings.
2802 ** CFI flashes may be simulated via the "cfi" device.
2804 *** Changes in GDB 7.2
2806 * Shared library support for remote targets by default
2808 When GDB is configured for a generic, non-OS specific target, like
2809 for example, --target=arm-eabi or one of the many *-*-elf targets,
2810 GDB now queries remote stubs for loaded shared libraries using the
2811 `qXfer:libraries:read' packet. Previously, shared library support
2812 was always disabled for such configurations.
2816 ** Argument Dependent Lookup (ADL)
2818 In C++ ADL lookup directs function search to the namespaces of its
2819 arguments even if the namespace has not been imported.
2829 Here the compiler will search for `foo' in the namespace of 'b'
2830 and find A::foo. GDB now supports this. This construct is commonly
2831 used in the Standard Template Library for operators.
2833 ** Improved User Defined Operator Support
2835 In addition to member operators, GDB now supports lookup of operators
2836 defined in a namespace and imported with a `using' directive, operators
2837 defined in the global scope, operators imported implicitly from an
2838 anonymous namespace, and the ADL operators mentioned in the previous
2840 GDB now also supports proper overload resolution for all the previously
2841 mentioned flavors of operators.
2843 ** static const class members
2845 Printing of static const class members that are initialized in the
2846 class definition has been fixed.
2848 * Windows Thread Information Block access.
2850 On Windows targets, GDB now supports displaying the Windows Thread
2851 Information Block (TIB) structure. This structure is visible either
2852 by using the new command `info w32 thread-information-block' or, by
2853 dereferencing the new convenience variable named `$_tlb', a
2854 thread-specific pointer to the TIB. This feature is also supported
2855 when remote debugging using GDBserver.
2857 * Static tracepoints
2859 Static tracepoints are calls in the user program into a tracing
2860 library. One such library is a port of the LTTng kernel tracer to
2861 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2862 When debugging with GDBserver, GDB now supports combining the GDB
2863 tracepoint machinery with such libraries. For example: the user can
2864 use GDB to probe a static tracepoint marker (a call from the user
2865 program into the tracing library) with the new "strace" command (see
2866 "New commands" below). This creates a "static tracepoint" in the
2867 breakpoint list, that can be manipulated with the same feature set
2868 as fast and regular tracepoints. E.g., collect registers, local and
2869 global variables, collect trace state variables, and define
2870 tracepoint conditions. In addition, the user can collect extra
2871 static tracepoint marker specific data, by collecting the new
2872 $_sdata internal variable. When analyzing the trace buffer, you can
2873 inspect $_sdata like any other variable available to GDB. For more
2874 information, see the "Tracepoints" chapter in GDB user manual. New
2875 remote packets have been defined to support static tracepoints, see
2876 the "New remote packets" section below.
2878 * Better reconstruction of tracepoints after disconnected tracing
2880 GDB will attempt to download the original source form of tracepoint
2881 definitions when starting a trace run, and then will upload these
2882 upon reconnection to the target, resulting in a more accurate
2883 reconstruction of the tracepoints that are in use on the target.
2887 You can now exercise direct control over the ways that GDB can
2888 affect your program. For instance, you can disallow the setting of
2889 breakpoints, so that the program can run continuously (assuming
2890 non-stop mode). In addition, the "observer" variable is available
2891 to switch all of the different controls; in observer mode, GDB
2892 cannot affect the target's behavior at all, which is useful for
2893 tasks like diagnosing live systems in the field.
2895 * The new convenience variable $_thread holds the number of the
2898 * New remote packets
2902 Return the address of the Windows Thread Information Block of a given thread.
2906 In response to several of the tracepoint packets, the target may now
2907 also respond with a number of intermediate `qRelocInsn' request
2908 packets before the final result packet, to have GDB handle
2909 relocating an instruction to execute at a different address. This
2910 is particularly useful for stubs that support fast tracepoints. GDB
2911 reports support for this feature in the qSupported packet.
2915 List static tracepoint markers in the target program.
2919 List static tracepoint markers at a given address in the target
2922 qXfer:statictrace:read
2924 Read the static trace data collected (by a `collect $_sdata'
2925 tracepoint action). The remote stub reports support for this packet
2926 to gdb's qSupported query.
2930 Send the current settings of GDB's permission flags.
2934 Send part of the source (textual) form of a tracepoint definition,
2935 which includes location, conditional, and action list.
2937 * The source command now accepts a -s option to force searching for the
2938 script in the source search path even if the script name specifies
2941 * New features in the GDB remote stub, GDBserver
2943 - GDBserver now support tracepoints (including fast tracepoints, and
2944 static tracepoints). The feature is currently supported by the
2945 i386-linux and amd64-linux builds. See the "Tracepoints support
2946 in gdbserver" section in the manual for more information.
2948 GDBserver JIT compiles the tracepoint's conditional agent
2949 expression bytecode into native code whenever possible for low
2950 overhead dynamic tracepoints conditionals. For such tracepoints,
2951 an expression that examines program state is evaluated when the
2952 tracepoint is reached, in order to determine whether to capture
2953 trace data. If the condition is simple and false, processing the
2954 tracepoint finishes very quickly and no data is gathered.
2956 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2957 for static tracepoints support.
2959 - GDBserver now supports x86_64 Windows 64-bit debugging.
2961 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2962 it understands register description.
2964 * The --batch flag now disables pagination and queries.
2966 * X86 general purpose registers
2968 GDB now supports reading/writing byte, word and double-word x86
2969 general purpose registers directly. This means you can use, say,
2970 $ah or $ax to refer, respectively, to the byte register AH and
2971 16-bit word register AX that are actually portions of the 32-bit
2972 register EAX or 64-bit register RAX.
2974 * The `commands' command now accepts a range of breakpoints to modify.
2975 A plain `commands' following a command that creates multiple
2976 breakpoints affects all the breakpoints set by that command. This
2977 applies to breakpoints set by `rbreak', and also applies when a
2978 single `break' command creates multiple breakpoints (e.g.,
2979 breakpoints on overloaded c++ functions).
2981 * The `rbreak' command now accepts a filename specification as part of
2982 its argument, limiting the functions selected by the regex to those
2983 in the specified file.
2985 * Support for remote debugging Windows and SymbianOS shared libraries
2986 from Unix hosts has been improved. Non Windows GDB builds now can
2987 understand target reported file names that follow MS-DOS based file
2988 system semantics, such as file names that include drive letters and
2989 use the backslash character as directory separator. This makes it
2990 possible to transparently use the "set sysroot" and "set
2991 solib-search-path" on Unix hosts to point as host copies of the
2992 target's shared libraries. See the new command "set
2993 target-file-system-kind" described below, and the "Commands to
2994 specify files" section in the user manual for more information.
2998 eval template, expressions...
2999 Convert the values of one or more expressions under the control
3000 of the string template to a command line, and call it.
3002 set target-file-system-kind unix|dos-based|auto
3003 show target-file-system-kind
3004 Set or show the assumed file system kind for target reported file
3007 save breakpoints <filename>
3008 Save all current breakpoint definitions to a file suitable for use
3009 in a later debugging session. To read the saved breakpoint
3010 definitions, use the `source' command.
3012 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3015 info static-tracepoint-markers
3016 Display information about static tracepoint markers in the target.
3018 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3019 Define a static tracepoint by probing a marker at the given
3020 function, line, address, or marker ID.
3024 Enable and disable observer mode.
3026 set may-write-registers on|off
3027 set may-write-memory on|off
3028 set may-insert-breakpoints on|off
3029 set may-insert-tracepoints on|off
3030 set may-insert-fast-tracepoints on|off
3031 set may-interrupt on|off
3032 Set individual permissions for GDB effects on the target. Note that
3033 some of these settings can have undesirable or surprising
3034 consequences, particularly when changed in the middle of a session.
3035 For instance, disabling the writing of memory can prevent
3036 breakpoints from being inserted, cause single-stepping to fail, or
3037 even crash your program, if you disable after breakpoints have been
3038 inserted. However, GDB should not crash.
3040 set record memory-query on|off
3041 show record memory-query
3042 Control whether to stop the inferior if memory changes caused
3043 by an instruction cannot be recorded.
3048 The disassemble command now supports "start,+length" form of two arguments.
3052 ** GDB now provides a new directory location, called the python directory,
3053 where Python scripts written for GDB can be installed. The location
3054 of that directory is <data-directory>/python, where <data-directory>
3055 is the GDB data directory. For more details, see section `Scripting
3056 GDB using Python' in the manual.
3058 ** The GDB Python API now has access to breakpoints, symbols, symbol
3059 tables, program spaces, inferiors, threads and frame's code blocks.
3060 Additionally, GDB Parameters can now be created from the API, and
3061 manipulated via set/show in the CLI.
3063 ** New functions gdb.target_charset, gdb.target_wide_charset,
3064 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3066 ** New exception gdb.GdbError.
3068 ** Pretty-printers are now also looked up in the current program space.
3070 ** Pretty-printers can now be individually enabled and disabled.
3072 ** GDB now looks for names of Python scripts to auto-load in a
3073 special section named `.debug_gdb_scripts', in addition to looking
3074 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3076 * Tracepoint actions were unified with breakpoint commands. In particular,
3077 there are no longer differences in "info break" output for breakpoints and
3078 tracepoints and the "commands" command can be used for both tracepoints and
3079 regular breakpoints.
3083 ARM Symbian arm*-*-symbianelf*
3085 * D language support.
3086 GDB now supports debugging programs written in the D programming
3089 * GDB now supports the extended ptrace interface for PowerPC which is
3090 available since Linux kernel version 2.6.34. This automatically enables
3091 any hardware breakpoints and additional hardware watchpoints available in
3092 the processor. The old ptrace interface exposes just one hardware
3093 watchpoint and no hardware breakpoints.
3095 * GDB is now able to use the Data Value Compare (DVC) register available on
3096 embedded PowerPC processors to implement in hardware simple watchpoint
3097 conditions of the form:
3099 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3101 This works in native GDB running on Linux kernels with the extended ptrace
3102 interface mentioned above.
3104 *** Changes in GDB 7.1
3108 ** Namespace Support
3110 GDB now supports importing of namespaces in C++. This enables the
3111 user to inspect variables from imported namespaces. Support for
3112 namepace aliasing has also been added. So, if a namespace is
3113 aliased in the current scope (e.g. namepace C=A; ) the user can
3114 print variables using the alias (e.g. (gdb) print C::x).
3118 All known bugs relating to the printing of virtual base class were
3119 fixed. It is now possible to call overloaded static methods using a
3124 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3125 and reinterpret_cast<> are now handled by the C++ expression parser.
3129 Xilinx MicroBlaze microblaze-*-*
3134 Xilinx MicroBlaze microblaze
3137 * Multi-program debugging.
3139 GDB now has support for multi-program (a.k.a. multi-executable or
3140 multi-exec) debugging. This allows for debugging multiple inferiors
3141 simultaneously each running a different program under the same GDB
3142 session. See "Debugging Multiple Inferiors and Programs" in the
3143 manual for more information. This implied some user visible changes
3144 in the multi-inferior support. For example, "info inferiors" now
3145 lists inferiors that are not running yet or that have exited
3146 already. See also "New commands" and "New options" below.
3148 * New tracing features
3150 GDB's tracepoint facility now includes several new features:
3152 ** Trace state variables
3154 GDB tracepoints now include support for trace state variables, which
3155 are variables managed by the target agent during a tracing
3156 experiment. They are useful for tracepoints that trigger each
3157 other, so for instance one tracepoint can count hits in a variable,
3158 and then a second tracepoint has a condition that is true when the
3159 count reaches a particular value. Trace state variables share the
3160 $-syntax of GDB convenience variables, and can appear in both
3161 tracepoint actions and condition expressions. Use the "tvariable"
3162 command to create, and "info tvariables" to view; see "Trace State
3163 Variables" in the manual for more detail.
3167 GDB now includes an option for defining fast tracepoints, which
3168 targets may implement more efficiently, such as by installing a jump
3169 into the target agent rather than a trap instruction. The resulting
3170 speedup can be by two orders of magnitude or more, although the
3171 tradeoff is that some program locations on some target architectures
3172 might not allow fast tracepoint installation, for instance if the
3173 instruction to be replaced is shorter than the jump. To request a
3174 fast tracepoint, use the "ftrace" command, with syntax identical to
3175 the regular trace command.
3177 ** Disconnected tracing
3179 It is now possible to detach GDB from the target while it is running
3180 a trace experiment, then reconnect later to see how the experiment
3181 is going. In addition, a new variable disconnected-tracing lets you
3182 tell the target agent whether to continue running a trace if the
3183 connection is lost unexpectedly.
3187 GDB now has the ability to save the trace buffer into a file, and
3188 then use that file as a target, similarly to you can do with
3189 corefiles. You can select trace frames, print data that was
3190 collected in them, and use tstatus to display the state of the
3191 tracing run at the moment that it was saved. To create a trace
3192 file, use "tsave <filename>", and to use it, do "target tfile
3195 ** Circular trace buffer
3197 You can ask the target agent to handle the trace buffer as a
3198 circular buffer, discarding the oldest trace frames to make room for
3199 newer ones, by setting circular-trace-buffer to on. This feature may
3200 not be available for all target agents.
3205 The disassemble command, when invoked with two arguments, now requires
3206 the arguments to be comma-separated.
3209 The info variables command now displays variable definitions. Files
3210 which only declare a variable are not shown.
3213 The source command is now capable of sourcing Python scripts.
3214 This feature is dependent on the debugger being build with Python
3217 Related to this enhancement is also the introduction of a new command
3218 "set script-extension" (see below).
3220 * New commands (for set/show, see "New options" below)
3222 record save [<FILENAME>]
3223 Save a file (in core file format) containing the process record
3224 execution log for replay debugging at a later time.
3226 record restore <FILENAME>
3227 Restore the process record execution log that was saved at an
3228 earlier time, for replay debugging.
3230 add-inferior [-copies <N>] [-exec <FILENAME>]
3233 clone-inferior [-copies <N>] [ID]
3234 Make a new inferior ready to execute the same program another
3235 inferior has loaded.
3240 maint info program-spaces
3241 List the program spaces loaded into GDB.
3243 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3244 show remote interrupt-sequence
3245 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3246 as the sequence to the remote target in order to interrupt the execution.
3247 Ctrl-C is a default. Some system prefers BREAK which is high level of
3248 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3249 Magic SysRq g. It is BREAK signal and character 'g'.
3251 set remote interrupt-on-connect [on | off]
3252 show remote interrupt-on-connect
3253 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3254 remote target when gdb connects to it. This is needed when you debug
3257 set remotebreak [on | off]
3259 Deprecated. Use "set/show remote interrupt-sequence" instead.
3261 tvariable $NAME [ = EXP ]
3262 Create or modify a trace state variable.
3265 List trace state variables and their values.
3267 delete tvariable $NAME ...
3268 Delete one or more trace state variables.
3271 Evaluate the given expressions without collecting anything into the
3272 trace buffer. (Valid in tracepoint actions only.)
3274 ftrace FN / FILE:LINE / *ADDR
3275 Define a fast tracepoint at the given function, line, or address.
3277 * New expression syntax
3279 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3280 GDB now parses 0b101010 identically with 42.
3284 set follow-exec-mode new|same
3285 show follow-exec-mode
3286 Control whether GDB reuses the same inferior across an exec call or
3287 creates a new one. This is useful to be able to restart the old
3288 executable after the inferior having done an exec call.
3290 set default-collect EXPR, ...
3291 show default-collect
3292 Define a list of expressions to be collected at each tracepoint.
3293 This is a useful way to ensure essential items are not overlooked,
3294 such as registers or a critical global variable.
3296 set disconnected-tracing
3297 show disconnected-tracing
3298 If set to 1, the target is instructed to continue tracing if it
3299 loses its connection to GDB. If 0, the target is to stop tracing
3302 set circular-trace-buffer
3303 show circular-trace-buffer
3304 If set to on, the target is instructed to use a circular trace buffer
3305 and discard the oldest trace frames instead of stopping the trace due
3306 to a full trace buffer. If set to off, the trace stops when the buffer
3307 fills up. Some targets may not support this.
3309 set script-extension off|soft|strict
3310 show script-extension
3311 If set to "off", the debugger does not perform any script language
3312 recognition, and all sourced files are assumed to be GDB scripts.
3313 If set to "soft" (the default), files are sourced according to
3314 filename extension, falling back to GDB scripts if the first
3316 If set to "strict", files are sourced according to filename extension.
3318 set ada trust-PAD-over-XVS on|off
3319 show ada trust-PAD-over-XVS
3320 If off, activate a workaround against a bug in the debugging information
3321 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3322 the GCC sources for more information about the GNAT encoding and
3323 PAD types in particular). It is always safe to set this option to
3324 off, but this introduces a slight performance penalty. The default
3327 * Python API Improvements
3329 ** GDB provides the new class gdb.LazyString. This is useful in
3330 some pretty-printing cases. The new method gdb.Value.lazy_string
3331 provides a simple way to create objects of this type.
3333 ** The fields returned by gdb.Type.fields now have an
3334 `is_base_class' attribute.
3336 ** The new method gdb.Type.range returns the range of an array type.
3338 ** The new method gdb.parse_and_eval can be used to parse and
3339 evaluate an expression.
3341 * New remote packets
3344 Define a trace state variable.
3347 Get the current value of a trace state variable.
3350 Set desired tracing behavior upon disconnection.
3353 Set the trace buffer to be linear or circular.
3356 Get data about the tracepoints currently in use.
3360 Process record now works correctly with hardware watchpoints.
3362 Multiple bug fixes have been made to the mips-irix port, making it
3363 much more reliable. In particular:
3364 - Debugging threaded applications is now possible again. Previously,
3365 GDB would hang while starting the program, or while waiting for
3366 the program to stop at a breakpoint.
3367 - Attaching to a running process no longer hangs.
3368 - An error occurring while loading a core file has been fixed.
3369 - Changing the value of the PC register now works again. This fixes
3370 problems observed when using the "jump" command, or when calling
3371 a function from GDB, or even when assigning a new value to $pc.
3372 - With the "finish" and "return" commands, the return value for functions
3373 returning a small array is now correctly printed.
3374 - It is now possible to break on shared library code which gets executed
3375 during a shared library init phase (code executed while executing
3376 their .init section). Previously, the breakpoint would have no effect.
3377 - GDB is now able to backtrace through the signal handler for
3378 non-threaded programs.
3380 PIE (Position Independent Executable) programs debugging is now supported.
3381 This includes debugging execution of PIC (Position Independent Code) shared
3382 libraries although for that, it should be possible to run such libraries as an
3385 *** Changes in GDB 7.0
3387 * GDB now has an interface for JIT compilation. Applications that
3388 dynamically generate code can create symbol files in memory and register
3389 them with GDB. For users, the feature should work transparently, and
3390 for JIT developers, the interface is documented in the GDB manual in the
3391 "JIT Compilation Interface" chapter.
3393 * Tracepoints may now be conditional. The syntax is as for
3394 breakpoints; either an "if" clause appended to the "trace" command,
3395 or the "condition" command is available. GDB sends the condition to
3396 the target for evaluation using the same bytecode format as is used
3397 for tracepoint actions.
3399 * The disassemble command now supports: an optional /r modifier, print the
3400 raw instructions in hex as well as in symbolic form, and an optional /m
3401 modifier to print mixed source+assembly.
3403 * Process record and replay
3405 In a architecture environment that supports ``process record and
3406 replay'', ``process record and replay'' target can record a log of
3407 the process execution, and replay it with both forward and reverse
3410 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3411 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3412 set execution-direction {forward|reverse}, for targets that support
3415 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3416 feature is available with a native GDB running on kernel version
3419 * GDB now has support for multi-byte and wide character sets on the
3420 target. Strings whose character type is wchar_t, char16_t, or
3421 char32_t are now correctly printed. GDB supports wide- and unicode-
3422 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3423 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3424 `printf'. This feature requires iconv to work properly; if your
3425 system does not have a working iconv, GDB can use GNU libiconv. See
3426 the installation instructions for more information.
3428 * GDB now supports automatic retrieval of shared library files from
3429 remote targets. To use this feature, specify a system root that begins
3430 with the `remote:' prefix, either via the `set sysroot' command or via
3431 the `--with-sysroot' configure-time option.
3433 * "info sharedlibrary" now takes an optional regex of libraries to show,
3434 and it now reports if a shared library has no debugging information.
3436 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3437 now complete on file names.
3439 * When completing in expressions, gdb will attempt to limit
3440 completions to allowable structure or union fields, where appropriate.
3441 For instance, consider:
3443 # struct example { int f1; double f2; };
3444 # struct example variable;
3447 If the user types TAB at the end of this command line, the available
3448 completions will be "f1" and "f2".
3450 * Inlined functions are now supported. They show up in backtraces, and
3451 the "step", "next", and "finish" commands handle them automatically.
3453 * GDB now supports the token-splicing (##) and stringification (#)
3454 operators when expanding macros. It also supports variable-arity
3457 * GDB now supports inspecting extra signal information, exported by
3458 the new $_siginfo convenience variable. The feature is currently
3459 implemented on linux ARM, i386 and amd64.
3461 * GDB can now display the VFP floating point registers and NEON vector
3462 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3463 can provide these registers (requires Linux 2.6.30 or later). Remote
3464 and simulator targets may also provide them.
3466 * New remote packets
3469 Search memory for a sequence of bytes.
3472 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3473 operation over reliable transport links. Use of this packet is
3474 controlled by the `set remote noack-packet' command.
3477 Kill the process with the specified process ID. Use this in preference
3478 to `k' when multiprocess protocol extensions are supported.
3481 Obtains additional operating system information
3485 Read or write additional signal information.
3487 * Removed remote protocol undocumented extension
3489 An undocumented extension to the remote protocol's `S' stop reply
3490 packet that permited the stub to pass a process id was removed.
3491 Remote servers should use the `T' stop reply packet instead.
3493 * GDB now supports multiple function calling conventions according to the
3494 DWARF-2 DW_AT_calling_convention function attribute.
3496 * The SH target utilizes the aforementioned change to distinguish between gcc
3497 and Renesas calling convention. It also adds the new CLI commands
3498 `set/show sh calling-convention'.
3500 * GDB can now read compressed debug sections, as produced by GNU gold
3501 with the --compress-debug-sections=zlib flag.
3503 * 64-bit core files are now supported on AIX.
3505 * Thread switching is now supported on Tru64.
3507 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3508 which will be allocated using malloc later in program execution.
3510 * The qXfer:libraries:read remote procotol packet now allows passing a
3511 list of section offsets.
3513 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3514 conditions handling signals delivered during attach or thread creation
3515 have also been fixed.
3517 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3518 From the user's standpoint, all unqualified instances of True and False
3519 are treated as the standard definitions, regardless of context.
3521 * GDB now parses C++ symbol and type names more flexibly. For
3524 template<typename T> class C { };
3527 GDB will now correctly handle all of:
3529 ptype C<char const *>
3530 ptype C<char const*>
3531 ptype C<const char *>
3532 ptype C<const char*>
3534 * New features in the GDB remote stub, gdbserver
3536 - The "--wrapper" command-line argument tells gdbserver to use a
3537 wrapper program to launch programs for debugging.
3539 - On PowerPC and S/390 targets, it is now possible to use a single
3540 gdbserver executable to debug both 32-bit and 64-bit programs.
3541 (This requires gdbserver itself to be built as a 64-bit executable.)
3543 - gdbserver uses the new noack protocol mode for TCP connections to
3544 reduce communications latency, if also supported and enabled in GDB.
3546 - Support for the sparc64-linux-gnu target is now included in
3549 - The amd64-linux build of gdbserver now supports debugging both
3550 32-bit and 64-bit programs.
3552 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3553 now support hardware watchpoints, and will use them automatically
3558 GDB now has support for scripting using Python. Whether this is
3559 available is determined at configure time.
3561 New GDB commands can now be written in Python.
3563 * Ada tasking support
3565 Ada tasks can now be inspected in GDB. The following commands have
3569 Print the list of Ada tasks.
3571 Print detailed information about task number N.
3573 Print the task number of the current task.
3575 Switch the context of debugging to task number N.
3577 * Support for user-defined prefixed commands. The "define" command can
3578 add new commands to existing prefixes, e.g. "target".
3580 * Multi-inferior, multi-process debugging.
3582 GDB now has generalized support for multi-inferior debugging. See
3583 "Debugging Multiple Inferiors" in the manual for more information.
3584 Although availability still depends on target support, the command
3585 set is more uniform now. The GNU/Linux specific multi-forks support
3586 has been migrated to this new framework. This implied some user
3587 visible changes; see "New commands" and also "Removed commands"
3590 * Target descriptions can now describe the target OS ABI. See the
3591 "Target Description Format" section in the user manual for more
3594 * Target descriptions can now describe "compatible" architectures
3595 to indicate that the target can execute applications for a different
3596 architecture in addition to those for the main target architecture.
3597 See the "Target Description Format" section in the user manual for
3600 * Multi-architecture debugging.
3602 GDB now includes general supports for debugging applications on
3603 hybrid systems that use more than one single processor architecture
3604 at the same time. Each such hybrid architecture still requires
3605 specific support to be added. The only hybrid architecture supported
3606 in this version of GDB is the Cell Broadband Engine.
3608 * GDB now supports integrated debugging of Cell/B.E. applications that
3609 use both the PPU and SPU architectures. To enable support for hybrid
3610 Cell/B.E. debugging, you need to configure GDB to support both the
3611 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3612 --enable-targets configure option.
3614 * Non-stop mode debugging.
3616 For some targets, GDB now supports an optional mode of operation in
3617 which you can examine stopped threads while other threads continue
3618 to execute freely. This is referred to as non-stop mode, with the
3619 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3620 section in the user manual for more information.
3622 To be able to support remote non-stop debugging, a remote stub needs
3623 to implement the non-stop mode remote protocol extensions, as
3624 described in the "Remote Non-Stop" section of the user manual. The
3625 GDB remote stub, gdbserver, has been adjusted to support these
3626 extensions on linux targets.
3628 * New commands (for set/show, see "New options" below)
3630 catch syscall [NAME(S) | NUMBER(S)]
3631 Catch system calls. Arguments, which should be names of system
3632 calls or their numbers, mean catch only those syscalls. Without
3633 arguments, every syscall will be caught. When the inferior issues
3634 any of the specified syscalls, GDB will stop and announce the system
3635 call, both when it is called and when its call returns. This
3636 feature is currently available with a native GDB running on the
3637 Linux Kernel, under the following architectures: x86, x86_64,
3638 PowerPC and PowerPC64.
3640 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3642 Search memory for a sequence of bytes.
3644 maint set python print-stack
3645 maint show python print-stack
3646 Show a stack trace when an error is encountered in a Python script.
3649 Invoke CODE by passing it to the Python interpreter.
3654 These allow macros to be defined, undefined, and listed
3658 Show operating system information about processes.
3661 List the inferiors currently under GDB's control.
3664 Switch focus to inferior number NUM.
3667 Detach from inferior number NUM.
3670 Kill inferior number NUM.
3674 set spu stop-on-load
3675 show spu stop-on-load
3676 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3678 set spu auto-flush-cache
3679 show spu auto-flush-cache
3680 Control whether to automatically flush the software-managed cache
3681 during Cell/B.E. debugging.
3683 set sh calling-convention
3684 show sh calling-convention
3685 Control the calling convention used when calling SH target functions.
3688 show debug timestamp
3689 Control display of timestamps with GDB debugging output.
3691 set disassemble-next-line
3692 show disassemble-next-line
3693 Control display of disassembled source lines or instructions when
3696 set remote noack-packet
3697 show remote noack-packet
3698 Set/show the use of remote protocol QStartNoAckMode packet. See above
3699 under "New remote packets."
3701 set remote query-attached-packet
3702 show remote query-attached-packet
3703 Control use of remote protocol `qAttached' (query-attached) packet.
3705 set remote read-siginfo-object
3706 show remote read-siginfo-object
3707 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3710 set remote write-siginfo-object
3711 show remote write-siginfo-object
3712 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3715 set remote reverse-continue
3716 show remote reverse-continue
3717 Control use of remote protocol 'bc' (reverse-continue) packet.
3719 set remote reverse-step
3720 show remote reverse-step
3721 Control use of remote protocol 'bs' (reverse-step) packet.
3723 set displaced-stepping
3724 show displaced-stepping
3725 Control displaced stepping mode. Displaced stepping is a way to
3726 single-step over breakpoints without removing them from the debuggee.
3727 Also known as "out-of-line single-stepping".
3730 show debug displaced
3731 Control display of debugging info for displaced stepping.
3733 maint set internal-error
3734 maint show internal-error
3735 Control what GDB does when an internal error is detected.
3737 maint set internal-warning
3738 maint show internal-warning
3739 Control what GDB does when an internal warning is detected.
3744 Use a wrapper program to launch programs for debugging.
3746 set multiple-symbols (all|ask|cancel)
3747 show multiple-symbols
3748 The value of this variable can be changed to adjust the debugger behavior
3749 when an expression or a breakpoint location contains an ambiguous symbol
3750 name (an overloaded function name, for instance).
3752 set breakpoint always-inserted
3753 show breakpoint always-inserted
3754 Keep breakpoints always inserted in the target, as opposed to inserting
3755 them when resuming the target, and removing them when the target stops.
3756 This option can improve debugger performance on slow remote targets.
3758 set arm fallback-mode (arm|thumb|auto)
3759 show arm fallback-mode
3760 set arm force-mode (arm|thumb|auto)
3762 These commands control how ARM GDB determines whether instructions
3763 are ARM or Thumb. The default for both settings is auto, which uses
3764 the current CPSR value for instructions without symbols; previous
3765 versions of GDB behaved as if "set arm fallback-mode arm".
3767 set disable-randomization
3768 show disable-randomization
3769 Standalone programs run with the virtual address space randomization enabled
3770 by default on some platforms. This option keeps the addresses stable across
3771 multiple debugging sessions.
3775 Control whether other threads are stopped or not when some thread hits
3780 Requests that asynchronous execution is enabled in the target, if available.
3781 In this case, it's possible to resume target in the background, and interact
3782 with GDB while the target is running. "show target-async" displays the
3783 current state of asynchronous execution of the target.
3785 set target-wide-charset
3786 show target-wide-charset
3787 The target-wide-charset is the name of the character set that GDB
3788 uses when printing characters whose type is wchar_t.
3790 set tcp auto-retry (on|off)
3792 set tcp connect-timeout
3793 show tcp connect-timeout
3794 These commands allow GDB to retry failed TCP connections to a remote stub
3795 with a specified timeout period; this is useful if the stub is launched
3796 in parallel with GDB but may not be ready to accept connections immediately.
3798 set libthread-db-search-path
3799 show libthread-db-search-path
3800 Control list of directories which GDB will search for appropriate
3803 set schedule-multiple (on|off)
3804 show schedule-multiple
3805 Allow GDB to resume all threads of all processes or only threads of
3806 the current process.
3810 Use more aggressive caching for accesses to the stack. This improves
3811 performance of remote debugging (particularly backtraces) without
3812 affecting correctness.
3814 set interactive-mode (on|off|auto)
3815 show interactive-mode
3816 Control whether GDB runs in interactive mode (on) or not (off).
3817 When in interactive mode, GDB waits for the user to answer all
3818 queries. Otherwise, GDB does not wait and assumes the default
3819 answer. When set to auto (the default), GDB determines which
3820 mode to use based on the stdin settings.
3825 For program forks, this is replaced by the new more generic `info
3826 inferiors' command. To list checkpoints, you can still use the
3827 `info checkpoints' command, which was an alias for the `info forks'
3831 Replaced by the new `inferior' command. To switch between
3832 checkpoints, you can still use the `restart' command, which was an
3833 alias for the `fork' command.
3836 This is removed, since some targets don't have a notion of
3837 processes. To switch between processes, you can still use the
3838 `inferior' command using GDB's own inferior number.
3841 For program forks, this is replaced by the new more generic `kill
3842 inferior' command. To delete a checkpoint, you can still use the
3843 `delete checkpoint' command, which was an alias for the `delete
3847 For program forks, this is replaced by the new more generic `detach
3848 inferior' command. To detach a checkpoint, you can still use the
3849 `detach checkpoint' command, which was an alias for the `detach
3852 * New native configurations
3854 x86/x86_64 Darwin i[34567]86-*-darwin*
3856 x86_64 MinGW x86_64-*-mingw*
3860 Lattice Mico32 lm32-*
3861 x86 DICOS i[34567]86-*-dicos*
3862 x86_64 DICOS x86_64-*-dicos*
3865 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3866 (mingw32ce) debugging.
3872 These commands were actually not implemented on any target.
3874 *** Changes in GDB 6.8
3876 * New native configurations
3878 NetBSD/hppa hppa*-*netbsd*
3879 Xtensa GNU/Linux xtensa*-*-linux*
3883 NetBSD/hppa hppa*-*-netbsd*
3884 Xtensa GNU/Lunux xtensa*-*-linux*
3886 * Change in command line behavior -- corefiles vs. process ids.
3888 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3889 attaching to process NUMBER fails, GDB no longer attempts to open a
3890 core file named NUMBER. Attaching to a program using the -c option
3891 is no longer supported. Instead, use the '-p' or '--pid' options.
3893 * GDB can now be built as a native debugger for debugging Windows x86
3894 (mingw32) Portable Executable (PE) programs.
3896 * Pending breakpoints no longer change their number when their address
3899 * GDB now supports breakpoints with multiple locations,
3900 including breakpoints on C++ constructors, inside C++ templates,
3901 and in inlined functions.
3903 * GDB's ability to debug optimized code has been improved. GDB more
3904 accurately identifies function bodies and lexical blocks that occupy
3905 more than one contiguous range of addresses.
3907 * Target descriptions can now describe registers for PowerPC.
3909 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3910 registers on PowerPC targets.
3912 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3913 targets even when the libthread_db library is not available.
3915 * The GDB remote stub, gdbserver, now supports the new file transfer
3916 commands (remote put, remote get, and remote delete).
3918 * The GDB remote stub, gdbserver, now supports run and attach in
3919 extended-remote mode.
3921 * hppa*64*-*-hpux11* target broken
3922 The debugger is unable to start a program and fails with the following
3923 error: "Error trying to get information about dynamic linker".
3924 The gdb-6.7 release is also affected.
3926 * GDB now supports the --enable-targets= configure option to allow
3927 building a single GDB executable that supports multiple remote
3928 target architectures.
3930 * GDB now supports debugging C and C++ programs which use the
3931 Decimal Floating Point extension. In addition, the PowerPC target
3932 now has a set of pseudo-registers to inspect decimal float values
3933 stored in two consecutive float registers.
3935 * The -break-insert MI command can optionally create pending
3938 * Improved support for debugging Ada
3939 Many improvements to the Ada language support have been made. These
3941 - Better support for Ada2005 interface types
3942 - Improved handling of arrays and slices in general
3943 - Better support for Taft-amendment types
3944 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3946 - Improved command completion in Ada
3949 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3954 set print frame-arguments (all|scalars|none)
3955 show print frame-arguments
3956 The value of this variable can be changed to control which argument
3957 values should be printed by the debugger when displaying a frame.
3962 Transfer files to and from a remote target, and delete remote files.
3969 Transfer files to and from a remote target, and delete remote files.
3971 * New remote packets
3978 Open, close, read, write, and delete files on the remote system.
3981 Attach to an existing process on the remote system, in extended-remote
3985 Run a new process on the remote system, in extended-remote mode.
3987 *** Changes in GDB 6.7
3989 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3990 bfd, libiberty and opcodes, as revealed by static analysis donated by
3991 Coverity, Inc. (http://scan.coverity.com).
3993 * When looking up multiply-defined global symbols, GDB will now prefer the
3994 symbol definition in the current shared library if it was built using the
3995 -Bsymbolic linker option.
3997 * When the Text User Interface (TUI) is not configured, GDB will now
3998 recognize the -tui command-line option and print a message that the TUI
4001 * The GDB remote stub, gdbserver, now has lower overhead for high
4002 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4004 * GDB for MIPS targets now autodetects whether a remote target provides
4005 32-bit or 64-bit register values.
4007 * Support for C++ member pointers has been improved.
4009 * GDB now understands XML target descriptions, which specify the
4010 target's overall architecture. GDB can read a description from
4011 a local file or over the remote serial protocol.
4013 * Vectors of single-byte data use a new integer type which is not
4014 automatically displayed as character or string data.
4016 * The /s format now works with the print command. It displays
4017 arrays of single-byte integers and pointers to single-byte integers
4020 * Target descriptions can now describe target-specific registers,
4021 for architectures which have implemented the support (currently
4022 only ARM, M68K, and MIPS).
4024 * GDB and the GDB remote stub, gdbserver, now support the XScale
4027 * The GDB remote stub, gdbserver, has been updated to support
4028 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4029 has been rewritten to use the standard GDB remote protocol.
4031 * GDB can now step into C++ functions which are called through thunks.
4033 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4035 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4036 layout. It also supports a TextSeg= and DataSeg= response when only
4037 segment base addresses (rather than offsets) are available.
4039 * The /i format now outputs any trailing branch delay slot instructions
4040 immediately following the last instruction within the count specified.
4042 * The GDB remote protocol "T" stop reply packet now supports a
4043 "library" response. Combined with the new "qXfer:libraries:read"
4044 packet, this response allows GDB to debug shared libraries on targets
4045 where the operating system manages the list of loaded libraries (e.g.
4046 Windows and SymbianOS).
4048 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4049 (DLLs) on Windows and Windows CE targets.
4051 * GDB now supports a faster verification that a .debug file matches its binary
4052 according to its build-id signature, if the signature is present.
4058 Enable or disable hardware flow control (RTS/CTS) on the serial port
4059 when debugging using remote targets.
4061 set mem inaccessible-by-default
4062 show mem inaccessible-by-default
4063 If the target supplies a memory map, for instance via the remote
4064 protocol's "qXfer:memory-map:read" packet, setting this variable
4065 prevents GDB from accessing memory outside the memory map. This
4066 is useful for targets with memory mapped registers or which react
4067 badly to accesses of unmapped address space.
4069 set breakpoint auto-hw
4070 show breakpoint auto-hw
4071 If the target supplies a memory map, for instance via the remote
4072 protocol's "qXfer:memory-map:read" packet, setting this variable
4073 lets GDB use hardware breakpoints automatically for memory regions
4074 where it can not use software breakpoints. This covers both the
4075 "break" command and internal breakpoints used for other commands
4076 including "next" and "finish".
4079 catch exception unhandled
4080 Stop the program execution when Ada exceptions are raised.
4083 Stop the program execution when an Ada assertion failed.
4087 Set an alternate system root for target files. This is a more
4088 general version of "set solib-absolute-prefix", which is now
4089 an alias to "set sysroot".
4092 Provide extended SPU facility status information. This set of
4093 commands is available only when debugging the Cell/B.E. SPU
4096 * New native configurations
4098 OpenBSD/sh sh*-*openbsd*
4101 unset tdesc filename
4103 Use the specified local file as an XML target description, and do
4104 not query the target for its built-in description.
4108 OpenBSD/sh sh*-*-openbsd*
4109 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4110 Toshiba Media Processor mep-elf
4112 * New remote packets
4115 Ignore the specified signals; pass them directly to the debugged program
4116 without stopping other threads or reporting them to GDB.
4118 qXfer:features:read:
4119 Read an XML target description from the target, which describes its
4124 Read or write contents of an spufs file on the target system. These
4125 packets are available only on the Cell/B.E. SPU architecture.
4127 qXfer:libraries:read:
4128 Report the loaded shared libraries. Combined with new "T" packet
4129 response, this packet allows GDB to debug shared libraries on
4130 targets where the operating system manages the list of loaded
4131 libraries (e.g. Windows and SymbianOS).
4135 Support for these obsolete configurations has been removed.
4143 i[34567]86-*-lynxos*
4144 i[34567]86-*-netware*
4145 i[34567]86-*-sco3.2v5*
4146 i[34567]86-*-sco3.2v4*
4148 i[34567]86-*-sysv4.2*
4151 i[34567]86-*-unixware2*
4152 i[34567]86-*-unixware*
4161 * Other removed features
4168 Various m68k-only ROM monitors.
4175 Various Renesas ROM monitors and debugging interfaces for SH and
4180 Support for a Macraigor serial interface to on-chip debugging.
4181 GDB does not directly support the newer parallel or USB
4186 A debug information format. The predecessor to DWARF 2 and
4187 DWARF 3, which are still supported.
4189 Support for the HP aCC compiler on HP-UX/PA-RISC
4191 SOM-encapsulated symbolic debugging information, automatic
4192 invocation of pxdb, and the aCC custom C++ ABI. This does not
4193 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4194 with aCC can still be debugged on an assembly level.
4196 MIPS ".pdr" sections
4198 A MIPS-specific format used to describe stack frame layout
4199 in debugging information.
4203 GDB could work with an older version of Guile to debug
4204 the interpreter and Scheme programs running in it.
4206 set mips stack-arg-size
4207 set mips saved-gpreg-size
4209 Use "set mips abi" to control parameter passing for MIPS.
4211 *** Changes in GDB 6.6
4216 Cell Broadband Engine SPU spu-elf
4218 * GDB can now be configured as a cross-debugger targeting native Windows
4219 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4220 running on a Windows system over TCP/IP to debug Windows programs.
4222 * The GDB remote stub, gdbserver, has been updated to support Windows and
4223 Cygwin debugging. Both single-threaded and multi-threaded programs are
4226 * The "set trust-readonly-sections" command works again. This command was
4227 broken in GDB 6.3, 6.4, and 6.5.
4229 * The "load" command now supports writing to flash memory, if the remote
4230 stub provides the required support.
4232 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4233 longer requires symbolic debug information (e.g. DWARF-2).
4238 unset substitute-path
4239 show substitute-path
4240 Manage a list of substitution rules that GDB uses to rewrite the name
4241 of the directories where the sources are located. This can be useful
4242 for instance when the sources were moved to a different location
4243 between compilation and debugging.
4247 Print each CLI command as it is executed. Each command is prefixed with
4248 a number of `+' symbols representing the nesting depth.
4249 The source command now has a `-v' option to enable the same feature.
4253 The ARM Demon monitor support (RDP protocol, "target rdp").
4255 Kernel Object Display, an embedded debugging feature which only worked with
4256 an obsolete version of Cisco IOS.
4258 The 'set download-write-size' and 'show download-write-size' commands.
4260 * New remote packets
4263 Tell a stub about GDB client features, and request remote target features.
4264 The first feature implemented is PacketSize, which allows the target to
4265 specify the size of packets it can handle - to minimize the number of
4266 packets required and improve performance when connected to a remote
4270 Fetch an OS auxilliary vector from the remote stub. This packet is a
4271 more efficient replacement for qPart:auxv:read.
4273 qXfer:memory-map:read:
4274 Fetch a memory map from the remote stub, including information about
4275 RAM, ROM, and flash memory devices.
4280 Erase and program a flash memory device.
4282 * Removed remote packets
4285 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4286 used it, and only gdbserver implemented it.
4288 *** Changes in GDB 6.5
4292 Renesas M32C/M16C m32c-elf
4294 Morpho Technologies ms1 ms1-elf
4298 init-if-undefined Initialize a convenience variable, but
4299 only if it doesn't already have a value.
4301 The following commands are presently only implemented for native GNU/Linux:
4303 checkpoint Save a snapshot of the program state.
4305 restart <n> Return the program state to a
4306 previously saved state.
4308 info checkpoints List currently saved checkpoints.
4310 delete-checkpoint <n> Delete a previously saved checkpoint.
4312 set|show detach-on-fork Tell gdb whether to detach from a newly
4313 forked process, or to keep debugging it.
4315 info forks List forks of the user program that
4316 are available to be debugged.
4318 fork <n> Switch to debugging one of several
4319 forks of the user program that are
4320 available to be debugged.
4322 delete-fork <n> Delete a fork from the list of forks
4323 that are available to be debugged (and
4324 kill the forked process).
4326 detach-fork <n> Delete a fork from the list of forks
4327 that are available to be debugged (and
4328 allow the process to continue).
4332 Morpho Technologies ms2 ms1-elf
4334 * Improved Windows host support
4336 GDB now builds as a cross debugger hosted on i686-mingw32, including
4337 native console support, and remote communications using either
4338 network sockets or serial ports.
4340 * Improved Modula-2 language support
4342 GDB can now print most types in the Modula-2 syntax. This includes:
4343 basic types, set types, record types, enumerated types, range types,
4344 pointer types and ARRAY types. Procedure var parameters are correctly
4345 printed and hexadecimal addresses and character constants are also
4346 written in the Modula-2 syntax. Best results can be obtained by using
4347 GNU Modula-2 together with the -gdwarf-2 command line option.
4351 The ARM rdi-share module.
4353 The Netware NLM debug server.
4355 *** Changes in GDB 6.4
4357 * New native configurations
4359 OpenBSD/arm arm*-*-openbsd*
4360 OpenBSD/mips64 mips64-*-openbsd*
4364 Morpho Technologies ms1 ms1-elf
4366 * New command line options
4368 --batch-silent As for --batch, but totally silent.
4369 --return-child-result The debugger will exist with the same value
4370 the child (debugged) program exited with.
4371 --eval-command COMMAND, -ex COMMAND
4372 Execute a single GDB CLI command. This may be
4373 specified multiple times and in conjunction
4374 with the --command (-x) option.
4376 * Deprecated commands removed
4378 The following commands, that were deprecated in 2000, have been
4382 set|show arm disassembly-flavor set|show arm disassembler
4383 othernames set arm disassembler
4384 set|show remotedebug set|show debug remote
4385 set|show archdebug set|show debug arch
4386 set|show eventdebug set|show debug event
4389 * New BSD user-level threads support
4391 It is now possible to debug programs using the user-level threads
4392 library on OpenBSD and FreeBSD. Currently supported (target)
4395 FreeBSD/amd64 x86_64-*-freebsd*
4396 FreeBSD/i386 i386-*-freebsd*
4397 OpenBSD/i386 i386-*-openbsd*
4399 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4400 are not yet supported.
4402 * New support for Matsushita MN10300 w/sim added
4403 (Work in progress). mn10300-elf.
4405 * REMOVED configurations and files
4407 VxWorks and the XDR protocol *-*-vxworks
4408 Motorola MCORE mcore-*-*
4409 National Semiconductor NS32000 ns32k-*-*
4411 * New "set print array-indexes" command
4413 After turning this setting "on", GDB prints the index of each element
4414 when displaying arrays. The default is "off" to preserve the previous
4417 * VAX floating point support
4419 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4421 * User-defined command support
4423 In addition to using $arg0..$arg9 for argument passing, it is now possible
4424 to use $argc to determine now many arguments have been passed. See the
4425 section on user-defined commands in the user manual for more information.
4427 *** Changes in GDB 6.3:
4429 * New command line option
4431 GDB now accepts -l followed by a number to set the timeout for remote
4434 * GDB works with GCC -feliminate-dwarf2-dups
4436 GDB now supports a more compact representation of DWARF-2 debug
4437 information using DW_FORM_ref_addr references. These are produced
4438 by GCC with the option -feliminate-dwarf2-dups and also by some
4439 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4440 to use -feliminate-dwarf2-dups.
4442 * Internationalization
4444 When supported by the host system, GDB will be built with
4445 internationalization (libintl). The task of marking up the sources is
4446 continued, we're looking forward to our first translation.
4450 Initial support for debugging programs compiled with the GNAT
4451 implementation of the Ada programming language has been integrated
4452 into GDB. In this release, support is limited to expression evaluation.
4454 * New native configurations
4456 GNU/Linux/m32r m32r-*-linux-gnu
4460 GDB's remote protocol now includes support for the 'p' packet. This
4461 packet is used to fetch individual registers from a remote inferior.
4463 * END-OF-LIFE registers[] compatibility module
4465 GDB's internal register infrastructure has been completely rewritten.
4466 The new infrastructure making possible the implementation of key new
4467 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4470 GDB 6.3 will be the last release to include the the registers[]
4471 compatibility module that allowed out-of-date configurations to
4472 continue to work. This change directly impacts the following
4482 powerpc bdm protocol
4484 Unless there is activity to revive these configurations, they will be
4485 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4487 * OBSOLETE configurations and files
4489 Configurations that have been declared obsolete in this release have
4490 been commented out. Unless there is activity to revive these
4491 configurations, the next release of GDB will have their sources
4492 permanently REMOVED.
4501 *** Changes in GDB 6.2.1:
4503 * MIPS `break main; run' gave an heuristic-fence-post warning
4505 When attempting to run even a simple program, a warning about
4506 heuristic-fence-post being hit would be reported. This problem has
4509 * MIPS IRIX 'long double' crashed GDB
4511 When examining a long double variable, GDB would get a segmentation
4512 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4513 IRIX long double values).
4517 A bug in the VAX stack code was causing problems with the "next"
4518 command. This problem has been fixed.
4520 *** Changes in GDB 6.2:
4522 * Fix for ``many threads''
4524 On GNU/Linux systems that use the NPTL threads library, a program
4525 rapidly creating and deleting threads would confuse GDB leading to the
4528 ptrace: No such process.
4529 thread_db_get_info: cannot get thread info: generic error
4531 This problem has been fixed.
4533 * "-async" and "-noasync" options removed.
4535 Support for the broken "-noasync" option has been removed (it caused
4538 * New ``start'' command.
4540 This command runs the program until the begining of the main procedure.
4542 * New BSD Kernel Data Access Library (libkvm) interface
4544 Using ``target kvm'' it is now possible to debug kernel core dumps and
4545 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4546 platforms. Currently supported (native-only) configurations are:
4548 FreeBSD/amd64 x86_64-*-freebsd*
4549 FreeBSD/i386 i?86-*-freebsd*
4550 NetBSD/i386 i?86-*-netbsd*
4551 NetBSD/m68k m68*-*-netbsd*
4552 NetBSD/sparc sparc-*-netbsd*
4553 OpenBSD/amd64 x86_64-*-openbsd*
4554 OpenBSD/i386 i?86-*-openbsd*
4555 OpenBSD/m68k m68*-openbsd*
4556 OpenBSD/sparc sparc-*-openbsd*
4558 * Signal trampoline code overhauled
4560 Many generic problems with GDB's signal handling code have been fixed.
4561 These include: backtraces through non-contiguous stacks; recognition
4562 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4563 call; backtrace through a signal trampoline; step into and out of
4564 signal handlers; and single-stepping in the signal trampoline.
4566 Please note that kernel bugs are a limiting factor here. These
4567 features have been shown to work on an s390 GNU/Linux system that
4568 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4570 * Cygwin support for DWARF 2 added.
4572 * New native configurations
4574 GNU/Linux/hppa hppa*-*-linux*
4575 OpenBSD/hppa hppa*-*-openbsd*
4576 OpenBSD/m68k m68*-*-openbsd*
4577 OpenBSD/m88k m88*-*-openbsd*
4578 OpenBSD/powerpc powerpc-*-openbsd*
4579 NetBSD/vax vax-*-netbsd*
4580 OpenBSD/vax vax-*-openbsd*
4582 * END-OF-LIFE frame compatibility module
4584 GDB's internal frame infrastructure has been completely rewritten.
4585 The new infrastructure making it possible to support key new features
4586 including DWARF 2 Call Frame Information. To aid in the task of
4587 migrating old configurations to this new infrastructure, a
4588 compatibility module, that allowed old configurations to continue to
4589 work, was also included.
4591 GDB 6.2 will be the last release to include this frame compatibility
4592 module. This change directly impacts the following configurations:
4602 Unless there is activity to revive these configurations, they will be
4603 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4605 * REMOVED configurations and files
4607 Sun 3, running SunOS 3 m68*-*-sunos3*
4608 Sun 3, running SunOS 4 m68*-*-sunos4*
4609 Sun 2, running SunOS 3 m68000-*-sunos3*
4610 Sun 2, running SunOS 4 m68000-*-sunos4*
4611 Motorola 680x0 running LynxOS m68*-*-lynxos*
4612 AT&T 3b1/Unix pc m68*-att-*
4613 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4614 decstation mips-dec-* mips-little-*
4615 riscos mips-*-riscos* mips-*-sysv*
4616 sonymips mips-sony-*
4617 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4619 *** Changes in GDB 6.1.1:
4621 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4623 The TUI (Text-mode User Interface) is now built as part of a default
4624 GDB configuration. It is enabled by either selecting the TUI with the
4625 command line option "-i=tui" or by running the separate "gdbtui"
4626 program. For more information on the TUI, see the manual "Debugging
4629 * Pending breakpoint support (also included in GDB 6.1)
4631 Support has been added to allow you to specify breakpoints in shared
4632 libraries that have not yet been loaded. If a breakpoint location
4633 cannot be found, and the "breakpoint pending" option is set to auto,
4634 GDB queries you if you wish to make the breakpoint pending on a future
4635 shared-library load. If and when GDB resolves the breakpoint symbol,
4636 the pending breakpoint is removed as one or more regular breakpoints
4639 Pending breakpoints are very useful for GCJ Java debugging.
4641 * Fixed ISO-C build problems
4643 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4644 non ISO-C code that stopped them being built using a more strict ISO-C
4645 compiler (e.g., IBM's C compiler).
4647 * Fixed build problem on IRIX 5
4649 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4650 wasn't able to compile compile on an IRIX 5 system.
4652 * Added execute permission to gdb/gdbserver/configure
4654 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4655 permission. This bug would cause configure to fail on a number of
4656 systems (Solaris, IRIX). Ref: server/519.
4658 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4660 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4661 has been updated to use constant array sizes.
4663 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4665 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4666 its generated DWARF Call Frame Info. This encoding was causing GDB to
4667 panic, that panic has been fixed. Ref: gdb/1628.
4669 * Fixed a problem when examining parameters in shared library code.
4671 When examining parameters in optimized shared library code generated
4672 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4673 not available''. GDB now correctly displays the variable's value.
4675 *** Changes in GDB 6.1:
4677 * Removed --with-mmalloc
4679 Support for the mmalloc memory manager has been removed, as it
4680 conflicted with the internal gdb byte cache.
4682 * Changes in AMD64 configurations
4684 The AMD64 target now includes the %cs and %ss registers. As a result
4685 the AMD64 remote protocol has changed; this affects the floating-point
4686 and SSE registers. If you rely on those registers for your debugging,
4687 you should upgrade gdbserver on the remote side.
4689 * Revised SPARC target
4691 The SPARC target has been completely revised, incorporating the
4692 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4693 support for LynxOS and SunOS 4 has been dropped. Calling functions
4694 from within GDB on operating systems with a non-executable stack
4695 (Solaris, OpenBSD) now works.
4699 GDB has a new C++ demangler which does a better job on the mangled
4700 names generated by current versions of g++. It also runs faster, so
4701 with this and other changes gdb should now start faster on large C++
4704 * DWARF 2 Location Expressions
4706 GDB support for location expressions has been extended to support function
4707 arguments and frame bases. Older versions of GDB could crash when they
4710 * C++ nested types and namespaces
4712 GDB's support for nested types and namespaces in C++ has been
4713 improved, especially if you use the DWARF 2 debugging format. (This
4714 is the default for recent versions of GCC on most platforms.)
4715 Specifically, if you have a class "Inner" defined within a class or
4716 namespace "Outer", then GDB realizes that the class's name is
4717 "Outer::Inner", not simply "Inner". This should greatly reduce the
4718 frequency of complaints about not finding RTTI symbols. In addition,
4719 if you are stopped at inside of a function defined within a namespace,
4720 GDB modifies its name lookup accordingly.
4722 * New native configurations
4724 NetBSD/amd64 x86_64-*-netbsd*
4725 OpenBSD/amd64 x86_64-*-openbsd*
4726 OpenBSD/alpha alpha*-*-openbsd*
4727 OpenBSD/sparc sparc-*-openbsd*
4728 OpenBSD/sparc64 sparc64-*-openbsd*
4730 * New debugging protocols
4732 M32R with SDI protocol m32r-*-elf*
4734 * "set prompt-escape-char" command deleted.
4736 The command "set prompt-escape-char" has been deleted. This command,
4737 and its very obscure effet on GDB's prompt, was never documented,
4738 tested, nor mentioned in the NEWS file.
4740 * OBSOLETE configurations and files
4742 Configurations that have been declared obsolete in this release have
4743 been commented out. Unless there is activity to revive these
4744 configurations, the next release of GDB will have their sources
4745 permanently REMOVED.
4747 Sun 3, running SunOS 3 m68*-*-sunos3*
4748 Sun 3, running SunOS 4 m68*-*-sunos4*
4749 Sun 2, running SunOS 3 m68000-*-sunos3*
4750 Sun 2, running SunOS 4 m68000-*-sunos4*
4751 Motorola 680x0 running LynxOS m68*-*-lynxos*
4752 AT&T 3b1/Unix pc m68*-att-*
4753 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4754 decstation mips-dec-* mips-little-*
4755 riscos mips-*-riscos* mips-*-sysv*
4756 sonymips mips-sony-*
4757 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4759 * REMOVED configurations and files
4761 SGI Irix-4.x mips-sgi-irix4 or iris4
4762 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4763 Z8000 simulator z8k-zilog-none or z8ksim
4764 Matsushita MN10200 w/simulator mn10200-*-*
4765 H8/500 simulator h8500-hitachi-hms or h8500hms
4766 HP/PA running BSD hppa*-*-bsd*
4767 HP/PA running OSF/1 hppa*-*-osf*
4768 HP/PA Pro target hppa*-*-pro*
4769 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4770 386BSD i[3456]86-*-bsd*
4771 Sequent family i[3456]86-sequent-sysv4*
4772 i[3456]86-sequent-sysv*
4773 i[3456]86-sequent-bsd*
4774 SPARC running LynxOS sparc-*-lynxos*
4775 SPARC running SunOS 4 sparc-*-sunos4*
4776 Tsqware Sparclet sparclet-*-*
4777 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4779 *** Changes in GDB 6.0:
4783 Support for debugging the Objective-C programming language has been
4784 integrated into GDB.
4786 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4788 DWARF 2's Call Frame Information makes available compiler generated
4789 information that more exactly describes the program's run-time stack.
4790 By using this information, GDB is able to provide more robust stack
4793 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4794 have been updated to use a new backtrace mechanism which includes
4795 DWARF 2 CFI support.
4799 GDB's remote protocol has been extended to include support for hosted
4800 file I/O (where the remote target uses GDB's file system). See GDB's
4801 remote protocol documentation for details.
4803 * All targets using the new architecture framework.
4805 All of GDB's targets have been updated to use the new internal
4806 architecture framework. The way is now open for future GDB releases
4807 to include cross-architecture native debugging support (i386 on amd64,
4810 * GNU/Linux's Thread Local Storage (TLS)
4812 GDB now includes support for for the GNU/Linux implementation of
4813 per-thread variables.
4815 * GNU/Linux's Native POSIX Thread Library (NPTL)
4817 GDB's thread code has been updated to work with either the new
4818 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4820 * Separate debug info.
4822 GDB, in conjunction with BINUTILS, now supports a mechanism for
4823 automatically loading debug information from a separate file. Instead
4824 of shipping full debug and non-debug versions of system libraries,
4825 system integrators can now instead ship just the stripped libraries
4826 and optional debug files.
4828 * DWARF 2 Location Expressions
4830 DWARF 2 Location Expressions allow the compiler to more completely
4831 describe the location of variables (even in optimized code) to the
4834 GDB now includes preliminary support for location expressions (support
4835 for DW_OP_piece is still missing).
4839 A number of long standing bugs that caused GDB to die while starting a
4840 Java application have been fixed. GDB's Java support is now
4841 considered "useable".
4843 * GNU/Linux support for fork, vfork, and exec.
4845 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4846 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4849 * GDB supports logging output to a file
4851 There are two new commands, "set logging" and "show logging", which can be
4852 used to capture GDB's output to a file.
4854 * The meaning of "detach" has changed for gdbserver
4856 The "detach" command will now resume the application, as documented. To
4857 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4860 * d10v, m68hc11 `regs' command deprecated
4862 The `info registers' command has been updated so that it displays the
4863 registers using a format identical to the old `regs' command.
4867 A new command, "maint set profile on/off", has been added. This command can
4868 be used to enable or disable profiling while running GDB, to profile a
4869 session or a set of commands. In addition there is a new configure switch,
4870 "--enable-profiling", which will cause GDB to be compiled with profiling
4871 data, for more informative profiling results.
4873 * Default MI syntax changed to "mi2".
4875 The default MI (machine interface) syntax, enabled by the command line
4876 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4877 "mi1", can be enabled by specifying the option "-i=mi1".
4879 Support for the original "mi0" syntax (included in GDB 5.0) has been
4882 Fix for gdb/192: removed extraneous space when displaying frame level.
4883 Fix for gdb/672: update changelist is now output in mi list format.
4884 Fix for gdb/702: a -var-assign that updates the value now shows up
4885 in a subsequent -var-update.
4887 * New native configurations.
4889 FreeBSD/amd64 x86_64-*-freebsd*
4891 * Multi-arched targets.
4893 HP/PA HPUX11 hppa*-*-hpux*
4894 Renesas M32R/D w/simulator m32r-*-elf*
4896 * OBSOLETE configurations and files
4898 Configurations that have been declared obsolete in this release have
4899 been commented out. Unless there is activity to revive these
4900 configurations, the next release of GDB will have their sources
4901 permanently REMOVED.
4903 Z8000 simulator z8k-zilog-none or z8ksim
4904 Matsushita MN10200 w/simulator mn10200-*-*
4905 H8/500 simulator h8500-hitachi-hms or h8500hms
4906 HP/PA running BSD hppa*-*-bsd*
4907 HP/PA running OSF/1 hppa*-*-osf*
4908 HP/PA Pro target hppa*-*-pro*
4909 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4910 Sequent family i[3456]86-sequent-sysv4*
4911 i[3456]86-sequent-sysv*
4912 i[3456]86-sequent-bsd*
4913 Tsqware Sparclet sparclet-*-*
4914 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4916 * REMOVED configurations and files
4919 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4920 IBM AIX PS/2 i[3456]86-*-aix
4921 i386 running Mach 3.0 i[3456]86-*-mach3*
4922 i386 running Mach i[3456]86-*-mach*
4923 i386 running OSF/1 i[3456]86-*osf1mk*
4924 HP/Apollo 68k Family m68*-apollo*-sysv*,
4926 m68*-hp-bsd*, m68*-hp-hpux*
4927 Argonaut Risc Chip (ARC) arc-*-*
4928 Mitsubishi D30V d30v-*-*
4929 Fujitsu FR30 fr30-*-elf*
4930 OS/9000 i[34]86-*-os9k
4931 I960 with MON960 i960-*-coff
4933 * MIPS $fp behavior changed
4935 The convenience variable $fp, for the MIPS, now consistently returns
4936 the address of the current frame's base. Previously, depending on the
4937 context, $fp could refer to either $sp or the current frame's base
4938 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4939 The GNU Source-Level Debugger''.
4941 *** Changes in GDB 5.3:
4943 * GNU/Linux shared library multi-threaded performance improved.
4945 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4946 `/proc', in preference to `ptrace' for memory reads. This may result
4947 in an improvement in the start-up time of multi-threaded, shared
4948 library applications when run under GDB. One GDB user writes: ``loads
4949 shared libs like mad''.
4951 * ``gdbserver'' now supports multi-threaded applications on some targets
4953 Support for debugging multi-threaded applications which use
4954 the GNU/Linux LinuxThreads package has been added for
4955 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4956 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4958 * GDB now supports C/C++ preprocessor macros.
4960 GDB now expands preprocessor macro invocations in C/C++ expressions,
4961 and provides various commands for showing macro definitions and how
4964 The new command `macro expand EXPRESSION' expands any macro
4965 invocations in expression, and shows the result.
4967 The new command `show macro MACRO-NAME' shows the definition of the
4968 macro named MACRO-NAME, and where it was defined.
4970 Most compilers don't include information about macros in the debugging
4971 information by default. In GCC 3.1, for example, you need to compile
4972 your program with the options `-gdwarf-2 -g3'. If the macro
4973 information is present in the executable, GDB will read it.
4975 * Multi-arched targets.
4977 DEC Alpha (partial) alpha*-*-*
4978 DEC VAX (partial) vax-*-*
4980 National Semiconductor NS32000 (partial) ns32k-*-*
4981 Motorola 68000 (partial) m68k-*-*
4982 Motorola MCORE mcore-*-*
4986 Fujitsu FRV architecture added by Red Hat frv*-*-*
4989 * New native configurations
4991 Alpha NetBSD alpha*-*-netbsd*
4992 SH NetBSD sh*-*-netbsdelf*
4993 MIPS NetBSD mips*-*-netbsd*
4994 UltraSPARC NetBSD sparc64-*-netbsd*
4996 * OBSOLETE configurations and files
4998 Configurations that have been declared obsolete in this release have
4999 been commented out. Unless there is activity to revive these
5000 configurations, the next release of GDB will have their sources
5001 permanently REMOVED.
5003 Mitsubishi D30V d30v-*-*
5004 OS/9000 i[34]86-*-os9k
5005 IBM AIX PS/2 i[3456]86-*-aix
5006 Fujitsu FR30 fr30-*-elf*
5007 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5008 Argonaut Risc Chip (ARC) arc-*-*
5009 i386 running Mach 3.0 i[3456]86-*-mach3*
5010 i386 running Mach i[3456]86-*-mach*
5011 i386 running OSF/1 i[3456]86-*osf1mk*
5012 HP/Apollo 68k Family m68*-apollo*-sysv*,
5014 m68*-hp-bsd*, m68*-hp-hpux*
5015 I960 with MON960 i960-*-coff
5017 * OBSOLETE languages
5019 CHILL, a Pascal like language used by telecommunications companies.
5021 * REMOVED configurations and files
5023 AMD 29k family via UDI a29k-amd-udi, udi29k
5024 A29K VxWorks a29k-*-vxworks
5025 AMD 29000 embedded, using EBMON a29k-none-none
5026 AMD 29000 embedded with COFF a29k-none-coff
5027 AMD 29000 embedded with a.out a29k-none-aout
5029 testsuite/gdb.hp/gdb.threads-hp/ directory
5031 * New command "set max-user-call-depth <nnn>"
5033 This command allows the user to limit the call depth of user-defined
5034 commands. The default is 1024.
5036 * Changes in FreeBSD/i386 native debugging.
5038 Support for the "generate-core-file" has been added.
5040 * New commands "dump", "append", and "restore".
5042 These commands allow data to be copied from target memory
5043 to a bfd-format or binary file (dump and append), and back
5044 from a file into memory (restore).
5046 * Improved "next/step" support on multi-processor Alpha Tru64.
5048 The previous single-step mechanism could cause unpredictable problems,
5049 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5050 of a software single-step mechanism prevents this.
5052 *** Changes in GDB 5.2.1:
5060 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5061 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5062 Fix, by Joel Brobecker imported from mainline.
5064 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5065 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5066 Fix, by Fred Fish, imported from mainline.
5068 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5069 Surprisingly enough, it works now.
5070 By Michal Ludvig, imported from mainline.
5072 i386 hardware watchpoint support:
5073 avoid misses on second run for some targets.
5074 By Pierre Muller, imported from mainline.
5076 *** Changes in GDB 5.2:
5078 * New command "set trust-readonly-sections on[off]".
5080 This command is a hint that tells gdb that read-only sections
5081 really are read-only (ie. that their contents will not change).
5082 In this mode, gdb will go to the object file rather than the
5083 target to read memory from read-only sections (such as ".text").
5084 This can be a significant performance improvement on some
5085 (notably embedded) targets.
5087 * New command "generate-core-file" (or "gcore").
5089 This new gdb command allows the user to drop a core file of the child
5090 process state at any time. So far it's been implemented only for
5091 GNU/Linux and Solaris, but should be relatively easily ported to other
5092 hosts. Argument is core file name (defaults to core.<pid>).
5094 * New command line option
5096 GDB now accepts --pid or -p followed by a process id.
5098 * Change in command line behavior -- corefiles vs. process ids.
5100 There is a subtle behavior in the way in which GDB handles
5101 command line arguments. The first non-flag argument is always
5102 a program to debug, but the second non-flag argument may either
5103 be a corefile or a process id. Previously, GDB would attempt to
5104 open the second argument as a corefile, and if that failed, would
5105 issue a superfluous error message and then attempt to attach it as
5106 a process. Now, if the second argument begins with a non-digit,
5107 it will be treated as a corefile. If it begins with a digit,
5108 GDB will attempt to attach it as a process, and if no such process
5109 is found, will then attempt to open it as a corefile.
5111 * Changes in ARM configurations.
5113 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5114 configuration is fully multi-arch.
5116 * New native configurations
5118 ARM NetBSD arm*-*-netbsd*
5119 x86 OpenBSD i[3456]86-*-openbsd*
5120 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5121 Sparc64 running FreeBSD sparc64-*-freebsd*
5125 Sanyo XStormy16 xstormy16-elf
5127 * OBSOLETE configurations and files
5129 Configurations that have been declared obsolete in this release have
5130 been commented out. Unless there is activity to revive these
5131 configurations, the next release of GDB will have their sources
5132 permanently REMOVED.
5134 AMD 29k family via UDI a29k-amd-udi, udi29k
5135 A29K VxWorks a29k-*-vxworks
5136 AMD 29000 embedded, using EBMON a29k-none-none
5137 AMD 29000 embedded with COFF a29k-none-coff
5138 AMD 29000 embedded with a.out a29k-none-aout
5140 testsuite/gdb.hp/gdb.threads-hp/ directory
5142 * REMOVED configurations and files
5144 TI TMS320C80 tic80-*-*
5146 PowerPC Solaris powerpcle-*-solaris*
5147 PowerPC Windows NT powerpcle-*-cygwin32
5148 PowerPC Netware powerpc-*-netware*
5149 Harris/CXUX m88k m88*-harris-cxux*
5150 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5151 ns32k-utek-sysv* ns32k-utek-*
5152 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5153 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5154 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5155 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5156 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5158 * Changes to command line processing
5160 The new `--args' feature can be used to specify command-line arguments
5161 for the inferior from gdb's command line.
5163 * Changes to key bindings
5165 There is a new `operate-and-get-next' function bound to `C-o'.
5167 *** Changes in GDB 5.1.1
5169 Fix compile problem on DJGPP.
5171 Fix a problem with floating-point registers on the i386 being
5174 Fix to stop GDB crashing on .debug_str debug info.
5176 Numerous documentation fixes.
5178 Numerous testsuite fixes.
5180 *** Changes in GDB 5.1:
5182 * New native configurations
5184 Alpha FreeBSD alpha*-*-freebsd*
5185 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5186 MIPS GNU/Linux mips*-*-linux*
5187 MIPS SGI Irix 6.x mips*-sgi-irix6*
5188 ia64 AIX ia64-*-aix*
5189 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5193 Motorola 68HC11 and 68HC12 m68hc11-elf
5195 UltraSparc running GNU/Linux sparc64-*-linux*
5197 * OBSOLETE configurations and files
5199 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5200 Harris/CXUX m88k m88*-harris-cxux*
5201 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5202 ns32k-utek-sysv* ns32k-utek-*
5203 TI TMS320C80 tic80-*-*
5205 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5206 PowerPC Solaris powerpcle-*-solaris*
5207 PowerPC Windows NT powerpcle-*-cygwin32
5208 PowerPC Netware powerpc-*-netware*
5209 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5210 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5211 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5212 Apple Macintosh (MPW) host N/A
5214 stuff.c (Program to stuff files into a specially prepared space in kdb)
5215 kdb-start.c (Main loop for the standalone kernel debugger)
5217 Configurations that have been declared obsolete in this release have
5218 been commented out. Unless there is activity to revive these
5219 configurations, the next release of GDB will have their sources
5220 permanently REMOVED.
5222 * REMOVED configurations and files
5224 Altos 3068 m68*-altos-*
5225 Convex c1-*-*, c2-*-*
5227 ARM RISCix arm-*-* (as host)
5231 * GDB has been converted to ISO C.
5233 GDB's source code has been converted to ISO C. In particular, the
5234 sources are fully protoized, and rely on standard headers being
5239 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5241 * The MI enabled by default.
5243 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5244 revised and enabled by default. Packages which use GDB as a debugging
5245 engine behind a UI or another front end are encouraged to switch to
5246 using the GDB/MI interface, instead of the old annotations interface
5247 which is now deprecated.
5249 * Support for debugging Pascal programs.
5251 GDB now includes support for debugging Pascal programs. The following
5252 main features are supported:
5254 - Pascal-specific data types such as sets;
5256 - automatic recognition of Pascal sources based on file-name
5259 - Pascal-style display of data types, variables, and functions;
5261 - a Pascal expression parser.
5263 However, some important features are not yet supported.
5265 - Pascal string operations are not supported at all;
5267 - there are some problems with boolean types;
5269 - Pascal type hexadecimal constants are not supported
5270 because they conflict with the internal variables format;
5272 - support for Pascal objects and classes is not full yet;
5274 - unlike Pascal, GDB is case-sensitive for symbol names.
5276 * Changes in completion.
5278 Commands such as `shell', `run' and `set args', which pass arguments
5279 to inferior programs, now complete on file names, similar to what
5280 users expect at the shell prompt.
5282 Commands which accept locations, such as `disassemble', `print',
5283 `breakpoint', `until', etc. now complete on filenames as well as
5284 program symbols. Thus, if you type "break foob TAB", and the source
5285 files linked into the programs include `foobar.c', that file name will
5286 be one of the candidates for completion. However, file names are not
5287 considered for completion after you typed a colon that delimits a file
5288 name from a name of a function in that file, as in "break foo.c:bar".
5290 `set demangle-style' completes on available demangling styles.
5292 * New platform-independent commands:
5294 It is now possible to define a post-hook for a command as well as a
5295 hook that runs before the command. For more details, see the
5296 documentation of `hookpost' in the GDB manual.
5298 * Changes in GNU/Linux native debugging.
5300 Support for debugging multi-threaded programs has been completely
5301 revised for all platforms except m68k and sparc. You can now debug as
5302 many threads as your system allows you to have.
5304 Attach/detach is supported for multi-threaded programs.
5306 Support for SSE registers was added for x86. This doesn't work for
5307 multi-threaded programs though.
5309 * Changes in MIPS configurations.
5311 Multi-arch support is enabled for all MIPS configurations.
5313 GDB can now be built as native debugger on SGI Irix 6.x systems for
5314 debugging n32 executables. (Debugging 64-bit executables is not yet
5317 * Unified support for hardware watchpoints in all x86 configurations.
5319 Most (if not all) native x86 configurations support hardware-assisted
5320 breakpoints and watchpoints in a unified manner. This support
5321 implements debug register sharing between watchpoints, which allows to
5322 put a virtually infinite number of watchpoints on the same address,
5323 and also supports watching regions up to 16 bytes with several debug
5326 The new maintenance command `maintenance show-debug-regs' toggles
5327 debugging print-outs in functions that insert, remove, and test
5328 watchpoints and hardware breakpoints.
5330 * Changes in the DJGPP native configuration.
5332 New command ``info dos sysinfo'' displays assorted information about
5333 the CPU, OS, memory, and DPMI server.
5335 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5336 display information about segment descriptors stored in GDT, LDT, and
5339 New commands ``info dos pde'' and ``info dos pte'' display entries
5340 from Page Directory and Page Tables (for now works with CWSDPMI only).
5341 New command ``info dos address-pte'' displays the Page Table entry for
5342 a given linear address.
5344 GDB can now pass command lines longer than 126 characters to the
5345 program being debugged (requires an update to the libdbg.a library
5346 which is part of the DJGPP development kit).
5348 DWARF2 debug info is now supported.
5350 It is now possible to `step' and `next' through calls to `longjmp'.
5352 * Changes in documentation.
5354 All GDB documentation was converted to GFDL, the GNU Free
5355 Documentation License.
5357 Tracepoints-related commands are now fully documented in the GDB
5360 TUI, the Text-mode User Interface, is now documented in the manual.
5362 Tracepoints-related commands are now fully documented in the GDB
5365 The "GDB Internals" manual now has an index. It also includes
5366 documentation of `ui_out' functions, GDB coding standards, x86
5367 hardware watchpoints, and memory region attributes.
5369 * GDB's version number moved to ``version.in''
5371 The Makefile variable VERSION has been replaced by the file
5372 ``version.in''. People creating GDB distributions should update the
5373 contents of this file.
5377 GUD support is now a standard part of the EMACS distribution.
5379 *** Changes in GDB 5.0:
5381 * Improved support for debugging FP programs on x86 targets
5383 Unified and much-improved support for debugging floating-point
5384 programs on all x86 targets. In particular, ``info float'' now
5385 displays the FP registers in the same format on all x86 targets, with
5386 greater level of detail.
5388 * Improvements and bugfixes in hardware-assisted watchpoints
5390 It is now possible to watch array elements, struct members, and
5391 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5392 on x86 targets no longer erroneously trigger when the address is
5395 * Improvements in the native DJGPP version of GDB
5397 The distribution now includes all the scripts and auxiliary files
5398 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5399 machines ``out of the box''.
5401 The DJGPP version can now debug programs that use signals. It is
5402 possible to catch signals that happened in the debuggee, deliver
5403 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5404 would kill the program being debugged.) Programs that hook hardware
5405 interrupts (keyboard, timer, etc.) can also be debugged.
5407 It is now possible to debug DJGPP programs that redirect their
5408 standard handles or switch them to raw (as opposed to cooked) mode, or
5409 even close them. The command ``run < foo > bar'' works as expected,
5410 and ``info terminal'' reports useful information about the debuggee's
5411 terminal, including raw/cooked mode, redirection, etc.
5413 The DJGPP version now uses termios functions for console I/O, which
5414 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5417 DOS-style file names with drive letters are now fully supported by
5420 It is now possible to debug DJGPP programs that switch their working
5421 directory. It is also possible to rerun the debuggee any number of
5422 times without restarting GDB; thus, you can use the same setup,
5423 breakpoints, etc. for many debugging sessions.
5425 * New native configurations
5427 ARM GNU/Linux arm*-*-linux*
5428 PowerPC GNU/Linux powerpc-*-linux*
5432 Motorola MCore mcore-*-*
5433 x86 VxWorks i[3456]86-*-vxworks*
5434 PowerPC VxWorks powerpc-*-vxworks*
5435 TI TMS320C80 tic80-*-*
5437 * OBSOLETE configurations
5439 Altos 3068 m68*-altos-*
5440 Convex c1-*-*, c2-*-*
5442 ARM RISCix arm-*-* (as host)
5445 Configurations that have been declared obsolete will be commented out,
5446 but the code will be left in place. If there is no activity to revive
5447 these configurations before the next release of GDB, the sources will
5448 be permanently REMOVED.
5450 * Gould support removed
5452 Support for the Gould PowerNode and NP1 has been removed.
5454 * New features for SVR4
5456 On SVR4 native platforms (such as Solaris), if you attach to a process
5457 without first loading a symbol file, GDB will now attempt to locate and
5458 load symbols from the running process's executable file.
5460 * Many C++ enhancements
5462 C++ support has been greatly improved. Overload resolution now works properly
5463 in almost all cases. RTTI support is on the way.
5465 * Remote targets can connect to a sub-program
5467 A popen(3) style serial-device has been added. This device starts a
5468 sub-process (such as a stand-alone simulator) and then communicates
5469 with that. The sub-program to run is specified using the syntax
5470 ``|<program> <args>'' vis:
5472 (gdb) set remotedebug 1
5473 (gdb) target extended-remote |mn10300-elf-sim program-args
5475 * MIPS 64 remote protocol
5477 A long standing bug in the mips64 remote protocol where by GDB
5478 expected certain 32 bit registers (ex SR) to be transfered as 32
5479 instead of 64 bits has been fixed.
5481 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5482 added to provide backward compatibility with older versions of GDB.
5484 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5486 The command ``set remotebinarydownload'' command has been replaced by
5487 ``set remote X-packet''. Other commands in ``set remote'' family
5488 include ``set remote P-packet''.
5490 * Breakpoint commands accept ranges.
5492 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5493 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5494 ``tracepoint passcount'' also accepts a range of tracepoints.
5496 * ``apropos'' command added.
5498 The ``apropos'' command searches through command names and
5499 documentation strings, printing out matches, making it much easier to
5500 try to find a command that does what you are looking for.
5504 A new machine oriented interface (MI) has been added to GDB. This
5505 interface is designed for debug environments running GDB as a separate
5506 process. This is part of the long term libGDB project. See the
5507 "GDB/MI" chapter of the GDB manual for further information. It can be
5508 enabled by configuring with:
5510 .../configure --enable-gdbmi
5512 *** Changes in GDB-4.18:
5514 * New native configurations
5516 HP-UX 10.20 hppa*-*-hpux10.20
5517 HP-UX 11.x hppa*-*-hpux11.0*
5518 M68K GNU/Linux m68*-*-linux*
5522 Fujitsu FR30 fr30-*-elf*
5523 Intel StrongARM strongarm-*-*
5524 Mitsubishi D30V d30v-*-*
5526 * OBSOLETE configurations
5528 Gould PowerNode, NP1 np1-*-*, pn-*-*
5530 Configurations that have been declared obsolete will be commented out,
5531 but the code will be left in place. If there is no activity to revive
5532 these configurations before the next release of GDB, the sources will
5533 be permanently REMOVED.
5537 As a compatibility experiment, GDB's source files buildsym.h and
5538 buildsym.c have been converted to pure standard C, no longer
5539 containing any K&R compatibility code. We believe that all systems in
5540 use today either come with a standard C compiler, or have a GCC port
5541 available. If this is not true, please report the affected
5542 configuration to bug-gdb@gnu.org immediately. See the README file for
5543 information about getting a standard C compiler if you don't have one
5548 GDB now uses readline 2.2.
5550 * set extension-language
5552 You can now control the mapping between filename extensions and source
5553 languages by using the `set extension-language' command. For instance,
5554 you can ask GDB to treat .c files as C++ by saying
5555 set extension-language .c c++
5556 The command `info extensions' lists all of the recognized extensions
5557 and their associated languages.
5559 * Setting processor type for PowerPC and RS/6000
5561 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5562 you can use the `set processor' command to specify what variant of the
5563 PowerPC family you are debugging. The command
5567 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5568 following PowerPC and RS6000 variants:
5570 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5571 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5573 403GC IBM PowerPC 403GC
5574 505 Motorola PowerPC 505
5575 860 Motorola PowerPC 860 or 850
5576 601 Motorola PowerPC 601
5577 602 Motorola PowerPC 602
5578 603 Motorola/IBM PowerPC 603 or 603e
5579 604 Motorola PowerPC 604 or 604e
5580 750 Motorola/IBM PowerPC 750 or 750
5582 At the moment, this command just tells GDB what to name the
5583 special-purpose processor registers. Since almost all the affected
5584 registers are inaccessible to user-level programs, this command is
5585 only useful for remote debugging in its present form.
5589 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5590 more extensive support for HP-UX. Added features include shared
5591 library support, kernel threads and hardware watchpoints for 11.00,
5592 support for HP's ANSI C and C++ compilers, and a compatibility mode
5593 for xdb and dbx commands.
5597 HP's donation includes the new concept of catchpoints, which is a
5598 generalization of the old catch command. On HP-UX, it is now possible
5599 to catch exec, fork, and vfork, as well as library loading.
5601 This means that the existing catch command has changed; its first
5602 argument now specifies the type of catch to be set up. See the
5603 output of "help catch" for a list of catchpoint types.
5605 * Debugging across forks
5607 On HP-UX, you can choose which process to debug when a fork() happens
5612 HP has donated a curses-based terminal user interface (TUI). To get
5613 it, build with --enable-tui. Although this can be enabled for any
5614 configuration, at present it only works for native HP debugging.
5616 * GDB remote protocol additions
5618 A new protocol packet 'X' that writes binary data is now available.
5619 Default behavior is to try 'X', then drop back to 'M' if the stub
5620 fails to respond. The settable variable `remotebinarydownload'
5621 allows explicit control over the use of 'X'.
5623 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5624 full 64-bit address. The command
5626 set remoteaddresssize 32
5628 can be used to revert to the old behaviour. For existing remote stubs
5629 the change should not be noticed, as the additional address information
5632 In order to assist in debugging stubs, you may use the maintenance
5633 command `packet' to send any text string to the stub. For instance,
5635 maint packet heythere
5637 sends the packet "$heythere#<checksum>". Note that it is very easy to
5638 disrupt a debugging session by sending the wrong packet at the wrong
5641 The compare-sections command allows you to compare section data on the
5642 target to what is in the executable file without uploading or
5643 downloading, by comparing CRC checksums.
5645 * Tracing can collect general expressions
5647 You may now collect general expressions at tracepoints. This requires
5648 further additions to the target-side stub; see tracepoint.c and
5649 doc/agentexpr.texi for further details.
5651 * mask-address variable for Mips
5653 For Mips targets, you may control the zeroing of the upper 32 bits of
5654 a 64-bit address by entering `set mask-address on'. This is mainly
5655 of interest to users of embedded R4xxx and R5xxx processors.
5657 * Higher serial baud rates
5659 GDB's serial code now allows you to specify baud rates 57600, 115200,
5660 230400, and 460800 baud. (Note that your host system may not be able
5661 to achieve all of these rates.)
5665 The i960 configuration now includes an initial implementation of a
5666 builtin simulator, contributed by Jim Wilson.
5669 *** Changes in GDB-4.17:
5671 * New native configurations
5673 Alpha GNU/Linux alpha*-*-linux*
5674 Unixware 2.x i[3456]86-unixware2*
5675 Irix 6.x mips*-sgi-irix6*
5676 PowerPC GNU/Linux powerpc-*-linux*
5677 PowerPC Solaris powerpcle-*-solaris*
5678 Sparc GNU/Linux sparc-*-linux*
5679 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5683 Argonaut Risc Chip (ARC) arc-*-*
5684 Hitachi H8/300S h8300*-*-*
5685 Matsushita MN10200 w/simulator mn10200-*-*
5686 Matsushita MN10300 w/simulator mn10300-*-*
5687 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5688 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5689 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5690 Mitsubishi D10V w/simulator d10v-*-*
5691 Mitsubishi M32R/D w/simulator m32r-*-elf*
5692 Tsqware Sparclet sparclet-*-*
5693 NEC V850 w/simulator v850-*-*
5695 * New debugging protocols
5697 ARM with RDI protocol arm*-*-*
5698 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5699 DDB and LSI variants of PMON protocol mips*-*-*
5700 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5701 PowerPC with SDS protocol powerpc{,le}-*-eabi
5702 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5706 All configurations can now understand and use the DWARF 2 debugging
5707 format. The choice is automatic, if the symbol file contains DWARF 2
5712 GDB now includes basic Java language support. This support is
5713 only useful with Java compilers that produce native machine code.
5715 * solib-absolute-prefix and solib-search-path
5717 For SunOS and SVR4 shared libraries, you may now set the prefix for
5718 loading absolute shared library symbol files, and the search path for
5719 locating non-absolute shared library symbol files.
5721 * Live range splitting
5723 GDB can now effectively debug code for which GCC has performed live
5724 range splitting as part of its optimization. See gdb/doc/LRS for
5725 more details on the expected format of the stabs information.
5729 GDB's support for the GNU Hurd, including thread debugging, has been
5730 updated to work with current versions of the Hurd.
5734 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5735 instruction set. ARM GDB automatically detects when Thumb
5736 instructions are in use, and adjusts disassembly and backtracing
5741 GDB's MIPS target configurations now handle the MIP16 16-bit
5746 GDB now includes support for overlays; if an executable has been
5747 linked such that multiple sections are based at the same address, GDB
5748 will decide which section to use for symbolic info. You can choose to
5749 control the decision manually, using overlay commands, or implement
5750 additional target-side support and use "overlay load-target" to bring
5751 in the overlay mapping. Do "help overlay" for more detail.
5755 The command "info symbol <address>" displays information about
5756 the symbol at the specified address.
5760 The standard remote protocol now includes an extension that allows
5761 asynchronous collection and display of trace data. This requires
5762 extensive support in the target-side debugging stub. Tracing mode
5763 includes a new interaction mode in GDB and new commands: see the
5764 file tracepoint.c for more details.
5768 Configurations for embedded MIPS now include a simulator contributed
5769 by Cygnus Solutions. The simulator supports the instruction sets
5770 of most MIPS variants.
5774 Sparc configurations may now include the ERC32 simulator contributed
5775 by the European Space Agency. The simulator is not built into
5776 Sparc targets by default; configure with --enable-sim to include it.
5780 For target configurations that may include multiple variants of a
5781 basic architecture (such as MIPS and SH), you may now set the
5782 architecture explicitly. "set arch" sets, "info arch" lists
5783 the possible architectures.
5785 *** Changes in GDB-4.16:
5787 * New native configurations
5789 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5790 M68K NetBSD m68k-*-netbsd*
5791 PowerPC AIX 4.x powerpc-*-aix*
5792 PowerPC MacOS powerpc-*-macos*
5793 PowerPC Windows NT powerpcle-*-cygwin32
5794 RS/6000 AIX 4.x rs6000-*-aix4*
5798 ARM with RDP protocol arm-*-*
5799 I960 with MON960 i960-*-coff
5800 MIPS VxWorks mips*-*-vxworks*
5801 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5802 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5804 Matra Sparclet sparclet-*-*
5808 The powerpc-eabi configuration now includes the PSIM simulator,
5809 contributed by Andrew Cagney, with assistance from Mike Meissner.
5810 PSIM is a very elaborate model of the PowerPC, including not only
5811 basic instruction set execution, but also details of execution unit
5812 performance and I/O hardware. See sim/ppc/README for more details.
5816 GDB now works with Solaris 2.5.
5818 * Windows 95/NT native
5820 GDB will now work as a native debugger on Windows 95 and Windows NT.
5821 To build it from source, you must use the "gnu-win32" environment,
5822 which uses a DLL to emulate enough of Unix to run the GNU tools.
5823 Further information, binaries, and sources are available at
5824 ftp.cygnus.com, under pub/gnu-win32.
5826 * dont-repeat command
5828 If a user-defined command includes the command `dont-repeat', then the
5829 command will not be repeated if the user just types return. This is
5830 useful if the command is time-consuming to run, so that accidental
5831 extra keystrokes don't run the same command many times.
5833 * Send break instead of ^C
5835 The standard remote protocol now includes an option to send a break
5836 rather than a ^C to the target in order to interrupt it. By default,
5837 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5839 * Remote protocol timeout
5841 The standard remote protocol includes a new variable `remotetimeout'
5842 that allows you to set the number of seconds before GDB gives up trying
5843 to read from the target. The default value is 2.
5845 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5847 By default GDB will automatically keep track of objects as they are
5848 loaded and unloaded by the dynamic linker. By using the command `set
5849 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5850 when shared library events occur, thus allowing you to set breakpoints
5851 in shared libraries which are explicitly loaded by the inferior.
5853 Note this feature does not work on hpux8. On hpux9 you must link
5854 /usr/lib/end.o into your program. This feature should work
5855 automatically on hpux10.
5857 * Irix 5.x hardware watchpoint support
5859 Irix 5 configurations now support the use of hardware watchpoints.
5861 * Mips protocol "SYN garbage limit"
5863 When debugging a Mips target using the `target mips' protocol, you
5864 may set the number of characters that GDB will ignore by setting
5865 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5866 every character. The default value is 1050.
5868 * Recording and replaying remote debug sessions
5870 If you set `remotelogfile' to the name of a file, gdb will write to it
5871 a recording of a remote debug session. This recording may then be
5872 replayed back to gdb using "gdbreplay". See gdbserver/README for
5873 details. This is useful when you have a problem with GDB while doing
5874 remote debugging; you can make a recording of the session and send it
5875 to someone else, who can then recreate the problem.
5877 * Speedups for remote debugging
5879 GDB includes speedups for downloading and stepping MIPS systems using
5880 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5881 and more efficient S-record downloading.
5883 * Memory use reductions and statistics collection
5885 GDB now uses less memory and reports statistics about memory usage.
5886 Try the `maint print statistics' command, for example.
5888 *** Changes in GDB-4.15:
5890 * Psymtabs for XCOFF
5892 The symbol reader for AIX GDB now uses partial symbol tables. This
5893 can greatly improve startup time, especially for large executables.
5895 * Remote targets use caching
5897 Remote targets now use a data cache to speed up communication with the
5898 remote side. The data cache could lead to incorrect results because
5899 it doesn't know about volatile variables, thus making it impossible to
5900 debug targets which use memory mapped I/O devices. `set remotecache
5901 off' turns the the data cache off.
5903 * Remote targets may have threads
5905 The standard remote protocol now includes support for multiple threads
5906 in the target system, using new protocol commands 'H' and 'T'. See
5907 gdb/remote.c for details.
5911 If GDB is configured with `--enable-netrom', then it will include
5912 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5913 acts as though it is a bank of ROM on the target board, but you can
5914 write into it over the network. GDB's support consists only of
5915 support for fast loading into the emulated ROM; to debug, you must use
5916 another protocol, such as standard remote protocol. The usual
5917 sequence is something like
5919 target nrom <netrom-hostname>
5921 target remote <netrom-hostname>:1235
5925 GDB now includes support for the Apple Macintosh, as a host only. It
5926 may be run as either an MPW tool or as a standalone application, and
5927 it can debug through the serial port. All the usual GDB commands are
5928 available, but to the target command, you must supply "serial" as the
5929 device type instead of "/dev/ttyXX". See mpw-README in the main
5930 directory for more information on how to build. The MPW configuration
5931 scripts */mpw-config.in support only a few targets, and only the
5932 mips-idt-ecoff target has been tested.
5936 GDB configuration now uses autoconf. This is not user-visible,
5937 but does simplify configuration and building.
5941 GDB now supports hpux10.
5943 *** Changes in GDB-4.14:
5945 * New native configurations
5947 x86 FreeBSD i[345]86-*-freebsd
5948 x86 NetBSD i[345]86-*-netbsd
5949 NS32k NetBSD ns32k-*-netbsd
5950 Sparc NetBSD sparc-*-netbsd
5954 A29K VxWorks a29k-*-vxworks
5955 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5956 CPU32 EST-300 emulator m68*-*-est*
5957 PowerPC ELF powerpc-*-elf
5960 * Alpha OSF/1 support for procfs
5962 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5963 possible to attach to running processes. As the mounting of the /proc
5964 filesystem is optional on the Alpha, GDB automatically determines
5965 the availability of /proc during startup. This can lead to problems
5966 if /proc is unmounted after GDB has been started.
5968 * Arguments to user-defined commands
5970 User commands may accept up to 10 arguments separated by whitespace.
5971 Arguments are accessed within the user command via $arg0..$arg9. A
5974 print $arg0 + $arg1 + $arg2
5976 To execute the command use:
5979 Defines the command "adder" which prints the sum of its three arguments.
5980 Note the arguments are text substitutions, so they may reference variables,
5981 use complex expressions, or even perform inferior function calls.
5983 * New `if' and `while' commands
5985 This makes it possible to write more sophisticated user-defined
5986 commands. Both commands take a single argument, which is the
5987 expression to evaluate, and must be followed by the commands to
5988 execute, one per line, if the expression is nonzero, the list being
5989 terminated by the word `end'. The `if' command list may include an
5990 `else' word, which causes the following commands to be executed only
5991 if the expression is zero.
5993 * Fortran source language mode
5995 GDB now includes partial support for Fortran 77. It will recognize
5996 Fortran programs and can evaluate a subset of Fortran expressions, but
5997 variables and functions may not be handled correctly. GDB will work
5998 with G77, but does not yet know much about symbols emitted by other
6001 * Better HPUX support
6003 Most debugging facilities now work on dynamic executables for HPPAs
6004 running hpux9 or later. You can attach to running dynamically linked
6005 processes, but by default the dynamic libraries will be read-only, so
6006 for instance you won't be able to put breakpoints in them. To change
6007 that behavior do the following before running the program:
6013 This will cause the libraries to be mapped private and read-write.
6014 To revert to the normal behavior, do this:
6020 You cannot set breakpoints or examine data in the library until after
6021 the library is loaded if the function/data symbols do not have
6024 GDB can now also read debug symbols produced by the HP C compiler on
6025 HPPAs (sorry, no C++, Fortran or 68k support).
6027 * Target byte order now dynamically selectable
6029 You can choose which byte order to use with a target system, via the
6030 commands "set endian big" and "set endian little", and you can see the
6031 current setting by using "show endian". You can also give the command
6032 "set endian auto", in which case GDB will use the byte order
6033 associated with the executable. Currently, only embedded MIPS
6034 configurations support dynamic selection of target byte order.
6036 * New DOS host serial code
6038 This version uses DPMI interrupts to handle buffered I/O, so you
6039 no longer need to run asynctsr when debugging boards connected to
6042 *** Changes in GDB-4.13:
6044 * New "complete" command
6046 This lists all the possible completions for the rest of the line, if it
6047 were to be given as a command itself. This is intended for use by emacs.
6049 * Trailing space optional in prompt
6051 "set prompt" no longer adds a space for you after the prompt you set. This
6052 allows you to set a prompt which ends in a space or one that does not.
6054 * Breakpoint hit counts
6056 "info break" now displays a count of the number of times the breakpoint
6057 has been hit. This is especially useful in conjunction with "ignore"; you
6058 can ignore a large number of breakpoint hits, look at the breakpoint info
6059 to see how many times the breakpoint was hit, then run again, ignoring one
6060 less than that number, and this will get you quickly to the last hit of
6063 * Ability to stop printing at NULL character
6065 "set print null-stop" will cause GDB to stop printing the characters of
6066 an array when the first NULL is encountered. This is useful when large
6067 arrays actually contain only short strings.
6069 * Shared library breakpoints
6071 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6072 breakpoints in shared libraries before the executable is run.
6074 * Hardware watchpoints
6076 There is a new hardware breakpoint for the watch command for sparclite
6077 targets. See gdb/sparclite/hw_breakpoint.note.
6079 Hardware watchpoints are also now supported under GNU/Linux.
6083 Annotations have been added. These are for use with graphical interfaces,
6084 and are still experimental. Currently only gdba.el uses these.
6086 * Improved Irix 5 support
6088 GDB now works properly with Irix 5.2.
6090 * Improved HPPA support
6092 GDB now works properly with the latest GCC and GAS.
6094 * New native configurations
6096 Sequent PTX4 i[34]86-sequent-ptx4
6097 HPPA running OSF/1 hppa*-*-osf*
6098 Atari TT running SVR4 m68*-*-sysv4*
6099 RS/6000 LynxOS rs6000-*-lynxos*
6103 OS/9000 i[34]86-*-os9k
6104 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6107 * Hitachi SH7000 and E7000-PC ICE support
6109 There is now support for communicating with the Hitachi E7000-PC ICE.
6110 This is available automatically when GDB is configured for the SH.
6114 As usual, a variety of small fixes and improvements, both generic
6115 and configuration-specific. See the ChangeLog for more detail.
6117 *** Changes in GDB-4.12:
6119 * Irix 5 is now supported
6123 GDB-4.12 on the HPPA has a number of changes which make it unable
6124 to debug the output from the currently released versions of GCC and
6125 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6126 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6127 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6130 *** Changes in GDB-4.11:
6132 * User visible changes:
6136 The "set remotedebug" option is now consistent between the mips remote
6137 target, remote targets using the gdb-specific protocol, UDI (AMD's
6138 debug protocol for the 29k) and the 88k bug monitor. It is now an
6139 integer specifying a debug level (normally 0 or 1, but 2 means more
6140 debugging info for the mips target).
6142 * DEC Alpha native support
6144 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6145 debug info, but GDB works fairly well with the DEC compiler and should
6146 work with a future GCC release. See the README file for a few
6147 Alpha-specific notes.
6149 * Preliminary thread implementation
6151 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6153 * LynxOS native and target support for 386
6155 This release has been hosted on LynxOS 2.2, and also can be configured
6156 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6159 * Improvements in C++ mangling/demangling.
6161 This release has much better g++ debugging, specifically in name
6162 mangling/demangling, virtual function calls, print virtual table,
6163 call methods, ...etc.
6165 *** Changes in GDB-4.10:
6167 * User visible changes:
6169 Remote debugging using the GDB-specific (`target remote') protocol now
6170 supports the `load' command. This is only useful if you have some
6171 other way of getting the stub to the target system, and you can put it
6172 somewhere in memory where it won't get clobbered by the download.
6174 Filename completion now works.
6176 When run under emacs mode, the "info line" command now causes the
6177 arrow to point to the line specified. Also, "info line" prints
6178 addresses in symbolic form (as well as hex).
6180 All vxworks based targets now support a user settable option, called
6181 vxworks-timeout. This option represents the number of seconds gdb
6182 should wait for responses to rpc's. You might want to use this if
6183 your vxworks target is, perhaps, a slow software simulator or happens
6184 to be on the far side of a thin network line.
6188 This release contains support for using a DEC alpha as a GDB host for
6189 cross debugging. Native alpha debugging is not supported yet.
6192 *** Changes in GDB-4.9:
6196 This is the first GDB release which is accompanied by a matching testsuite.
6197 The testsuite requires installation of dejagnu, which should be available
6198 via ftp from most sites that carry GNU software.
6202 'Cfront' style demangling has had its name changed to 'ARM' style, to
6203 emphasize that it was written from the specifications in the C++ Annotated
6204 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6205 disclaimers, it still generated too much confusion with users attempting to
6206 use gdb with AT&T cfront.
6210 GDB now uses a standard remote interface to a simulator library.
6211 So far, the library contains simulators for the Zilog Z8001/2, the
6212 Hitachi H8/300, H8/500 and Super-H.
6214 * New targets supported
6216 H8/300 simulator h8300-hitachi-hms or h8300hms
6217 H8/500 simulator h8500-hitachi-hms or h8500hms
6218 SH simulator sh-hitachi-hms or sh
6219 Z8000 simulator z8k-zilog-none or z8ksim
6220 IDT MIPS board over serial line mips-idt-ecoff
6222 Cross-debugging to GO32 targets is supported. It requires a custom
6223 version of the i386-stub.c module which is integrated with the
6224 GO32 memory extender.
6226 * New remote protocols
6228 MIPS remote debugging protocol.
6230 * New source languages supported
6232 This version includes preliminary support for Chill, a Pascal like language
6233 used by telecommunications companies. Chill support is also being integrated
6234 into the GNU compiler, but we don't know when it will be publically available.
6237 *** Changes in GDB-4.8:
6239 * HP Precision Architecture supported
6241 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6242 version of this support was available as a set of patches from the
6243 University of Utah. GDB does not support debugging of programs
6244 compiled with the HP compiler, because HP will not document their file
6245 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6246 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6248 Many problems in the preliminary version have been fixed.
6250 * Faster and better demangling
6252 We have improved template demangling and fixed numerous bugs in the GNU style
6253 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6254 character types (wchar_t) are now supported. Demangling of each symbol is now
6255 only done once, and is cached when the symbol table for a file is read in.
6256 This results in a small increase in memory usage for C programs, a moderate
6257 increase in memory usage for C++ programs, and a fantastic speedup in
6260 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6261 from the specifications in the Annotated Reference Manual, which AT&T's
6262 compiler does not actually implement.
6264 * G++ multiple inheritance compiler problem
6266 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6267 inheritance lattices was reworked to properly discover ambiguities. We
6268 recently found an example which causes this new algorithm to fail in a
6269 very subtle way, producing bad debug information for those classes.
6270 The file 'gcc.patch' (in this directory) can be applied to gcc to
6271 circumvent the problem. A future GCC release will contain a complete
6274 The previous G++ debug info problem (mentioned below for the gdb-4.7
6275 release) is fixed in gcc version 2.3.2.
6277 * Improved configure script
6279 The `configure' script will now attempt to guess your system type if
6280 you don't supply a host system type. The old scheme of supplying a
6281 host system triplet is preferable over using this. All the magic is
6282 done in the new `config.guess' script. Examine it for details.
6284 We have also brought our configure script much more in line with the FSF's
6285 version. It now supports the --with-xxx options. In particular,
6286 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6287 The resulting GDB will not be able to read arbitrary object file formats --
6288 only the format ``expected'' to be used on the configured target system.
6289 We hope to make this the default in a future release.
6291 * Documentation improvements
6293 There's new internal documentation on how to modify GDB, and how to
6294 produce clean changes to the code. We implore people to read it
6295 before submitting changes.
6297 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6298 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6299 `info' files are also provided. To build `info' files from scratch,
6300 you will need the latest `makeinfo' release, which will be available in
6301 a future texinfo-X.Y release.
6303 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6304 We're not sure exactly which versions have this problem, but it has
6305 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6306 or better. If that isn't possible, there is a patch in
6307 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6308 around this problem.
6312 GDB now supports array constants that can be used in expressions typed in by
6313 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6314 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6317 The new directory `gdb/sparclite' contains a program that demonstrates
6318 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6320 * New native hosts supported
6322 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6323 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6325 * New targets supported
6327 AMD 29k family via UDI a29k-amd-udi or udi29k
6329 * New file formats supported
6331 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6332 HPUX core files, and SCO 3.2v2 core files.
6336 Attaching to processes now works again; thanks for the many bug reports.
6338 We have also stomped on a bunch of core dumps caused by
6339 printf_filtered("%s") problems.
6341 We eliminated a copyright problem on the rpc and ptrace header files
6342 for VxWorks, which was discovered at the last minute during the 4.7
6343 release. You should now be able to build a VxWorks GDB.
6345 You can now interrupt gdb while an attached process is running. This
6346 will cause the attached process to stop, and give control back to GDB.
6348 We fixed problems caused by using too many file descriptors
6349 for reading symbols from object files and libraries. This was
6350 especially a problem for programs that used many (~100) shared
6353 The `step' command now only enters a subroutine if there is line number
6354 information for the subroutine. Otherwise it acts like the `next'
6355 command. Previously, `step' would enter subroutines if there was
6356 any debugging information about the routine. This avoids problems
6357 when using `cc -g1' on MIPS machines.
6359 * Internal improvements
6361 GDB's internal interfaces have been improved to make it easier to support
6362 debugging of multiple languages in the future.
6364 GDB now uses a common structure for symbol information internally.
6365 Minimal symbols (derived from linkage symbols in object files), partial
6366 symbols (from a quick scan of debug information), and full symbols
6367 contain a common subset of information, making it easier to write
6368 shared code that handles any of them.
6370 * New command line options
6372 We now accept --silent as an alias for --quiet.
6376 The memory-mapped-malloc library is now licensed under the GNU Library
6377 General Public License.
6379 *** Changes in GDB-4.7:
6381 * Host/native/target split
6383 GDB has had some major internal surgery to untangle the support for
6384 hosts and remote targets. Now, when you configure GDB for a remote
6385 target, it will no longer load in all of the support for debugging
6386 local programs on the host. When fully completed and tested, this will
6387 ensure that arbitrary host/target combinations are possible.
6389 The primary conceptual shift is to separate the non-portable code in
6390 GDB into three categories. Host specific code is required any time GDB
6391 is compiled on that host, regardless of the target. Target specific
6392 code relates to the peculiarities of the target, but can be compiled on
6393 any host. Native specific code is everything else: it can only be
6394 built when the host and target are the same system. Child process
6395 handling and core file support are two common `native' examples.
6397 GDB's use of /proc for controlling Unix child processes is now cleaner.
6398 It has been split out into a single module under the `target_ops' vector,
6399 plus two native-dependent functions for each system that uses /proc.
6401 * New hosts supported
6403 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6404 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6405 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6407 * New targets supported
6409 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6410 68030 and CPU32 m68030-*-*, m68332-*-*
6412 * New native hosts supported
6414 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6415 (386bsd is not well tested yet)
6416 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6418 * New file formats supported
6420 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6421 supports reading of `a.out.adobe' object files, which are an a.out
6422 format extended with minimal information about multiple sections.
6426 `show copying' is the same as the old `info copying'.
6427 `show warranty' is the same as `info warrantee'.
6428 These were renamed for consistency. The old commands continue to work.
6430 `info handle' is a new alias for `info signals'.
6432 You can now define pre-command hooks, which attach arbitrary command
6433 scripts to any command. The commands in the hook will be executed
6434 prior to the user's command. You can also create a hook which will be
6435 executed whenever the program stops. See gdb.texinfo.
6439 We now deal with Cfront style name mangling, and can even extract type
6440 info from mangled symbols. GDB can automatically figure out which
6441 symbol mangling style your C++ compiler uses.
6443 Calling of methods and virtual functions has been improved as well.
6447 The crash that occured when debugging Sun Ansi-C compiled binaries is
6448 fixed. This was due to mishandling of the extra N_SO stabs output
6451 We also finally got Ultrix 4.2 running in house, and fixed core file
6452 support, with help from a dozen people on the net.
6454 John M. Farrell discovered that the reason that single-stepping was so
6455 slow on all of the Mips based platforms (primarily SGI and DEC) was
6456 that we were trying to demangle and lookup a symbol used for internal
6457 purposes on every instruction that was being stepped through. Changing
6458 the name of that symbol so that it couldn't be mistaken for a C++
6459 mangled symbol sped things up a great deal.
6461 Rich Pixley sped up symbol lookups in general by getting much smarter
6462 about when C++ symbol mangling is necessary. This should make symbol
6463 completion (TAB on the command line) much faster. It's not as fast as
6464 we'd like, but it's significantly faster than gdb-4.6.
6468 A new user controllable variable 'call_scratch_address' can
6469 specify the location of a scratch area to be used when GDB
6470 calls a function in the target. This is necessary because the
6471 usual method of putting the scratch area on the stack does not work
6472 in systems that have separate instruction and data spaces.
6474 We integrated changes to support the 29k UDI (Universal Debugger
6475 Interface), but discovered at the last minute that we didn't have all
6476 of the appropriate copyright paperwork. We are working with AMD to
6477 resolve this, and hope to have it available soon.
6481 We have sped up the remote serial line protocol, especially for targets
6482 with lots of registers. It now supports a new `expedited status' ('T')
6483 message which can be used in place of the existing 'S' status message.
6484 This allows the remote stub to send only the registers that GDB
6485 needs to make a quick decision about single-stepping or conditional
6486 breakpoints, eliminating the need to fetch the entire register set for
6487 each instruction being stepped through.
6489 The GDB remote serial protocol now implements a write-through cache for
6490 registers, only re-reading the registers if the target has run.
6492 There is also a new remote serial stub for SPARC processors. You can
6493 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6494 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6495 processor with a serial port.
6499 Configure.in files have become much easier to read and modify. A new
6500 `table driven' format makes it more obvious what configurations are
6501 supported, and what files each one uses.
6505 There is a new opcodes library which will eventually contain all of the
6506 disassembly routines and opcode tables. At present, it only contains
6507 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6508 disassembler (binutils/objdump) to share these routines.
6510 The libiberty library is now copylefted under the GNU Library General
6511 Public License. This allows more liberal use, and was done so libg++
6512 can use it. This makes no difference to GDB, since the Library License
6513 grants all the rights from the General Public License.
6517 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6518 reference to the stabs symbol info used by the debugger. It is (as far
6519 as we know) the only published document on this fascinating topic. We
6520 encourage you to read it, compare it to the stabs information on your
6521 system, and send improvements on the document in general (to
6522 bug-gdb@prep.ai.mit.edu).
6524 And, of course, many bugs have been fixed.
6527 *** Changes in GDB-4.6:
6529 * Better support for C++ function names
6531 GDB now accepts as input the "demangled form" of C++ overloaded function
6532 names and member function names, and can do command completion on such names
6533 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6534 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6535 Make use of command completion, it is your friend.
6537 GDB also now accepts a variety of C++ mangled symbol formats. They are
6538 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6539 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6540 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6541 for the list of formats.
6543 * G++ symbol mangling problem
6545 Recent versions of gcc have a bug in how they emit debugging information for
6546 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6547 directory) can be applied to gcc to fix the problem. Alternatively, if you
6548 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6549 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6550 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6553 * New 'maintenance' command
6555 All of the commands related to hacking GDB internals have been moved out of
6556 the main command set, and now live behind the 'maintenance' command. This
6557 can also be abbreviated as 'mt'. The following changes were made:
6559 dump-me -> maintenance dump-me
6560 info all-breakpoints -> maintenance info breakpoints
6561 printmsyms -> maintenance print msyms
6562 printobjfiles -> maintenance print objfiles
6563 printpsyms -> maintenance print psymbols
6564 printsyms -> maintenance print symbols
6566 The following commands are new:
6568 maintenance demangle Call internal GDB demangler routine to
6569 demangle a C++ link name and prints the result.
6570 maintenance print type Print a type chain for a given symbol
6572 * Change to .gdbinit file processing
6574 We now read the $HOME/.gdbinit file before processing the argv arguments
6575 (e.g. reading symbol files or core files). This allows global parameters to
6576 be set, which will apply during the symbol reading. The ./.gdbinit is still
6577 read after argv processing.
6579 * New hosts supported
6581 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6583 GNU/Linux support i386-unknown-linux or linux
6585 We are also including code to support the HP/PA running BSD and HPUX. This
6586 is almost guaranteed not to work, as we didn't have time to test or build it
6587 for this release. We are including it so that the more adventurous (or
6588 masochistic) of you can play with it. We also had major problems with the
6589 fact that the compiler that we got from HP doesn't support the -g option.
6592 * New targets supported
6594 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6596 * More smarts about finding #include files
6598 GDB now remembers the compilation directory for all include files, and for
6599 all files from which C is generated (like yacc and lex sources). This
6600 greatly improves GDB's ability to find yacc/lex sources, and include files,
6601 especially if you are debugging your program from a directory different from
6602 the one that contains your sources.
6604 We also fixed a bug which caused difficulty with listing and setting
6605 breakpoints in include files which contain C code. (In the past, you had to
6606 try twice in order to list an include file that you hadn't looked at before.)
6608 * Interesting infernals change
6610 GDB now deals with arbitrary numbers of sections, where the symbols for each
6611 section must be relocated relative to that section's landing place in the
6612 target's address space. This work was needed to support ELF with embedded
6613 stabs used by Solaris-2.0.
6615 * Bug fixes (of course!)
6617 There have been loads of fixes for the following things:
6618 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6619 i960, stabs, DOS(GO32), procfs, etc...
6621 See the ChangeLog for details.
6623 *** Changes in GDB-4.5:
6625 * New machines supported (host and target)
6627 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6629 SGI Irix-4.x mips-sgi-irix4 or iris4
6631 * New malloc package
6633 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6634 Mmalloc is capable of handling mutiple heaps of memory. It is also
6635 capable of saving a heap to a file, and then mapping it back in later.
6636 This can be used to greatly speedup the startup of GDB by using a
6637 pre-parsed symbol table which lives in a mmalloc managed heap. For
6638 more details, please read mmalloc/mmalloc.texi.
6642 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6643 'help info proc' for details.
6645 * MIPS ecoff symbol table format
6647 The code that reads MIPS symbol table format is now supported on all hosts.
6648 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6651 * File name changes for MS-DOS
6653 Many files in the config directories have been renamed to make it easier to
6654 support GDB on MS-DOSe systems (which have very restrictive file name
6655 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6656 environment) is close to working but has some remaining problems. Note
6657 that debugging of DOS programs is not supported, due to limitations
6658 in the ``operating system'', but it can be used to host cross-debugging.
6660 * Cross byte order fixes
6662 Many fixes have been made to support cross debugging of Sparc and MIPS
6663 targets from hosts whose byte order differs.
6665 * New -mapped and -readnow options
6667 If memory-mapped files are available on your system through the 'mmap'
6668 system call, you can use the -mapped option on the `file' or
6669 `symbol-file' commands to cause GDB to write the symbols from your
6670 program into a reusable file. If the program you are debugging is
6671 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6672 Future GDB debugging sessions will notice the presence of this file,
6673 and will quickly map in symbol information from it, rather than reading
6674 the symbol table from the executable program. Using the '-mapped'
6675 option in a GDB `file' or `symbol-file' command has the same effect as
6676 starting GDB with the '-mapped' command-line option.
6678 You can cause GDB to read the entire symbol table immediately by using
6679 the '-readnow' option with any of the commands that load symbol table
6680 information (or on the GDB command line). This makes the command
6681 slower, but makes future operations faster.
6683 The -mapped and -readnow options are typically combined in order to
6684 build a `fred.syms' file that contains complete symbol information.
6685 A simple GDB invocation to do nothing but build a `.syms' file for future
6688 gdb -batch -nx -mapped -readnow programname
6690 The `.syms' file is specific to the host machine on which GDB is run.
6691 It holds an exact image of GDB's internal symbol table. It cannot be
6692 shared across multiple host platforms.
6694 * longjmp() handling
6696 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6697 siglongjmp() without losing control. This feature has not yet been ported to
6698 all systems. It currently works on many 386 platforms, all MIPS-based
6699 platforms (SGI, DECstation, etc), and Sun3/4.
6703 Preliminary work has been put in to support the new Solaris OS from Sun. At
6704 this time, it can control and debug processes, but it is not capable of
6709 As always, many many bug fixes. The major areas were with g++, and mipsread.
6710 People using the MIPS-based platforms should experience fewer mysterious
6711 crashes and trashed symbol tables.
6713 *** Changes in GDB-4.4:
6715 * New machines supported (host and target)
6717 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6719 BSD Reno on Vax vax-dec-bsd
6720 Ultrix on Vax vax-dec-ultrix
6722 * New machines supported (target)
6724 AMD 29000 embedded, using EBMON a29k-none-none
6728 GDB continues to improve its handling of C++. `References' work better.
6729 The demangler has also been improved, and now deals with symbols mangled as
6730 per the Annotated C++ Reference Guide.
6732 GDB also now handles `stabs' symbol information embedded in MIPS
6733 `ecoff' symbol tables. Since the ecoff format was not easily
6734 extensible to handle new languages such as C++, this appeared to be a
6735 good way to put C++ debugging info into MIPS binaries. This option
6736 will be supported in the GNU C compiler, version 2, when it is
6739 * New features for SVR4
6741 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6742 shared libraries. Debugging dynamically linked programs should present
6743 only minor differences from debugging statically linked programs.
6745 The `info proc' command will print out information about any process
6746 on an SVR4 system (including the one you are debugging). At the moment,
6747 it prints the address mappings of the process.
6749 If you bring up GDB on another SVR4 system, please send mail to
6750 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6752 * Better dynamic linking support in SunOS
6754 Reading symbols from shared libraries which contain debugging symbols
6755 now works properly. However, there remain issues such as automatic
6756 skipping of `transfer vector' code during function calls, which
6757 make it harder to debug code in a shared library, than to debug the
6758 same code linked statically.
6762 GDB is now using the latest `getopt' routines from the FSF. This
6763 version accepts the -- prefix for options with long names. GDB will
6764 continue to accept the old forms (-option and +option) as well.
6765 Various single letter abbreviations for options have been explicity
6766 added to the option table so that they won't get overshadowed in the
6767 future by other options that begin with the same letter.
6771 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6772 Many assorted bugs have been handled. Many more remain to be handled.
6773 See the various ChangeLog files (primarily in gdb and bfd) for details.
6776 *** Changes in GDB-4.3:
6778 * New machines supported (host and target)
6780 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6781 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6782 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6784 * Almost SCO Unix support
6786 We had hoped to support:
6787 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6788 (except for core file support), but we discovered very late in the release
6789 that it has problems with process groups that render gdb unusable. Sorry
6790 about that. I encourage people to fix it and post the fixes.
6792 * Preliminary ELF and DWARF support
6794 GDB can read ELF object files on System V Release 4, and can handle
6795 debugging records for C, in DWARF format, in ELF files. This support
6796 is preliminary. If you bring up GDB on another SVR4 system, please
6797 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6802 GDB now uses the latest `readline' library. One user-visible change
6803 is that two tabs will list possible command completions, which previously
6804 required typing M-? (meta-question mark, or ESC ?).
6808 The `stepi' bug that many of you noticed has been squashed.
6809 Many bugs in C++ have been handled. Many more remain to be handled.
6810 See the various ChangeLog files (primarily in gdb and bfd) for details.
6812 * State of the MIPS world (in case you wondered):
6814 GDB can understand the symbol tables emitted by the compilers
6815 supplied by most vendors of MIPS-based machines, including DEC. These
6816 symbol tables are in a format that essentially nobody else uses.
6818 Some versions of gcc come with an assembler post-processor called
6819 mips-tfile. This program is required if you want to do source-level
6820 debugging of gcc-compiled programs. I believe FSF does not ship
6821 mips-tfile with gcc version 1, but it will eventually come with gcc
6824 Debugging of g++ output remains a problem. g++ version 1.xx does not
6825 really support it at all. (If you're lucky, you should be able to get
6826 line numbers and stack traces to work, but no parameters or local
6827 variables.) With some work it should be possible to improve the
6830 When gcc version 2 is released, you will have somewhat better luck.
6831 However, even then you will get confusing results for inheritance and
6834 We will eventually provide full debugging of g++ output on
6835 DECstations. This will probably involve some kind of stabs-in-ecoff
6836 encapulation, but the details have not been worked out yet.
6839 *** Changes in GDB-4.2:
6841 * Improved configuration
6843 Only one copy of `configure' exists now, and it is not self-modifying.
6844 Porting BFD is simpler.
6848 The `step' and `next' commands now only stop at the first instruction
6849 of a source line. This prevents the multiple stops that used to occur
6850 in switch statements, for-loops, etc. `Step' continues to stop if a
6851 function that has debugging information is called within the line.
6855 Lots of small bugs fixed. More remain.
6857 * New host supported (not target)
6859 Intel 386 PC clone running Mach i386-none-mach
6862 *** Changes in GDB-4.1:
6864 * Multiple source language support
6866 GDB now has internal scaffolding to handle several source languages.
6867 It determines the type of each source file from its filename extension,
6868 and will switch expression parsing and number formatting to match the
6869 language of the function in the currently selected stack frame.
6870 You can also specifically set the language to be used, with
6871 `set language c' or `set language modula-2'.
6875 GDB now has preliminary support for the GNU Modula-2 compiler,
6876 currently under development at the State University of New York at
6877 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6878 continue through the fall of 1991 and into 1992.
6880 Other Modula-2 compilers are currently not supported, and attempting to
6881 debug programs compiled with them will likely result in an error as the
6882 symbol table is read. Feel free to work on it, though!
6884 There are hooks in GDB for strict type checking and range checking,
6885 in the `Modula-2 philosophy', but they do not currently work.
6889 GDB can now write to executable and core files (e.g. patch
6890 a variable's value). You must turn this switch on, specify
6891 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6892 by assigning a new value to a variable. Modifications take
6895 * Automatic SunOS shared library reading
6897 When you run your program, GDB automatically determines where its
6898 shared libraries (if any) have been loaded, and reads their symbols.
6899 The `share' command is no longer needed. This also works when
6900 examining core files.
6904 You can specify the number of lines that the `list' command shows.
6907 * New machines supported (host and target)
6909 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6910 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6911 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6913 * New hosts supported (not targets)
6915 IBM RT/PC: romp-ibm-aix or rtpc
6917 * New targets supported (not hosts)
6919 AMD 29000 embedded with COFF a29k-none-coff
6920 AMD 29000 embedded with a.out a29k-none-aout
6921 Ultracomputer remote kernel debug a29k-nyu-kern
6923 * New remote interfaces
6929 *** Changes in GDB-4.0:
6933 Wide output is wrapped at good places to make the output more readable.
6935 Gdb now supports cross-debugging from a host machine of one type to a
6936 target machine of another type. Communication with the target system
6937 is over serial lines. The ``target'' command handles connecting to the
6938 remote system; the ``load'' command will download a program into the
6939 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6940 also supports debugging of realtime processes running under VxWorks,
6941 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6942 stub on the target system.
6944 New CPUs supported include the AMD 29000 and Intel 960.
6946 GDB now reads object files and symbol tables via a ``binary file''
6947 library, which allows a single copy of GDB to debug programs of multiple
6948 object file types such as a.out and coff.
6950 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6951 refcard.dvi and refcard.ps are available to format it).
6954 * Control-Variable user interface simplified
6956 All variables that control the operation of the debugger can be set
6957 by the ``set'' command, and displayed by the ``show'' command.
6959 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6960 ``Show prompt'' produces the response:
6961 Gdb's prompt is new-gdb=>.
6963 What follows are the NEW set commands. The command ``help set'' will
6964 print a complete list of old and new set commands. ``help set FOO''
6965 will give a longer description of the variable FOO. ``show'' will show
6966 all of the variable descriptions and their current settings.
6968 confirm on/off: Enables warning questions for operations that are
6969 hard to recover from, e.g. rerunning the program while
6970 it is already running. Default is ON.
6972 editing on/off: Enables EMACS style command line editing
6973 of input. Previous lines can be recalled with
6974 control-P, the current line can be edited with control-B,
6975 you can search for commands with control-R, etc.
6978 history filename NAME: NAME is where the gdb command history
6979 will be stored. The default is .gdb_history,
6980 or the value of the environment variable
6983 history size N: The size, in commands, of the command history. The
6984 default is 256, or the value of the environment variable
6987 history save on/off: If this value is set to ON, the history file will
6988 be saved after exiting gdb. If set to OFF, the
6989 file will not be saved. The default is OFF.
6991 history expansion on/off: If this value is set to ON, then csh-like
6992 history expansion will be performed on
6993 command line input. The default is OFF.
6995 radix N: Sets the default radix for input and output. It can be set
6996 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6997 in the current radix, so "set radix 10" is always a no-op.
6999 height N: This integer value is the number of lines on a page. Default
7000 is 24, the current `stty rows'' setting, or the ``li#''
7001 setting from the termcap entry matching the environment
7004 width N: This integer value is the number of characters on a line.
7005 Default is 80, the current `stty cols'' setting, or the ``co#''
7006 setting from the termcap entry matching the environment
7009 Note: ``set screensize'' is obsolete. Use ``set height'' and
7010 ``set width'' instead.
7012 print address on/off: Print memory addresses in various command displays,
7013 such as stack traces and structure values. Gdb looks
7014 more ``symbolic'' if you turn this off; it looks more
7015 ``machine level'' with it on. Default is ON.
7017 print array on/off: Prettyprint arrays. New convenient format! Default
7020 print demangle on/off: Print C++ symbols in "source" form if on,
7023 print asm-demangle on/off: Same, for assembler level printouts
7026 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7029 * Support for Epoch Environment.
7031 The epoch environment is a version of Emacs v18 with windowing. One
7032 new command, ``inspect'', is identical to ``print'', except that if you
7033 are running in the epoch environment, the value is printed in its own
7037 * Support for Shared Libraries
7039 GDB can now debug programs and core files that use SunOS shared libraries.
7040 Symbols from a shared library cannot be referenced
7041 before the shared library has been linked with the program (this
7042 happens after you type ``run'' and before the function main() is entered).
7043 At any time after this linking (including when examining core files
7044 from dynamically linked programs), gdb reads the symbols from each
7045 shared library when you type the ``sharedlibrary'' command.
7046 It can be abbreviated ``share''.
7048 sharedlibrary REGEXP: Load shared object library symbols for files
7049 matching a unix regular expression. No argument
7050 indicates to load symbols for all shared libraries.
7052 info sharedlibrary: Status of loaded shared libraries.
7057 A watchpoint stops execution of a program whenever the value of an
7058 expression changes. Checking for this slows down execution
7059 tremendously whenever you are in the scope of the expression, but is
7060 quite useful for catching tough ``bit-spreader'' or pointer misuse
7061 problems. Some machines such as the 386 have hardware for doing this
7062 more quickly, and future versions of gdb will use this hardware.
7064 watch EXP: Set a watchpoint (breakpoint) for an expression.
7066 info watchpoints: Information about your watchpoints.
7068 delete N: Deletes watchpoint number N (same as breakpoints).
7069 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7070 enable N: Re-enables watchpoint number N (same as breakpoints).
7073 * C++ multiple inheritance
7075 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7078 * C++ exception handling
7080 Gdb now supports limited C++ exception handling. Besides the existing
7081 ability to breakpoint on an exception handler, gdb can breakpoint on
7082 the raising of an exception (before the stack is peeled back to the
7085 catch FOO: If there is a FOO exception handler in the dynamic scope,
7086 set a breakpoint to catch exceptions which may be raised there.
7087 Multiple exceptions (``catch foo bar baz'') may be caught.
7089 info catch: Lists all exceptions which may be caught in the
7090 current stack frame.
7093 * Minor command changes
7095 The command ``call func (arg, arg, ...)'' now acts like the print
7096 command, except it does not print or save a value if the function's result
7097 is void. This is similar to dbx usage.
7099 The ``up'' and ``down'' commands now always print the frame they end up
7100 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7101 frames without printing.
7103 * New directory command
7105 'dir' now adds directories to the FRONT of the source search path.
7106 The path starts off empty. Source files that contain debug information
7107 about the directory in which they were compiled can be found even
7108 with an empty path; Sun CC and GCC include this information. If GDB can't
7109 find your source file in the current directory, type "dir .".
7111 * Configuring GDB for compilation
7113 For normal use, type ``./configure host''. See README or gdb.texinfo
7116 GDB now handles cross debugging. If you are remotely debugging between
7117 two different machines, type ``./configure host -target=targ''.
7118 Host is the machine where GDB will run; targ is the machine
7119 where the program that you are debugging will run.