1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB now has experimental support for the compilation and injection of
7 C++ source code into the inferior. This beta release does not include
8 support for several language features, such as templates, constructors,
11 This feature requires GCC 7.1 or higher built with libcp1.so
14 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
15 can be passed using the '[ADDRESS]:PORT' notation, or the regular
16 'ADDRESS:PORT' method.
18 * DWARF index cache: GDB can now automatically save indices of DWARF
19 symbols on disk to speed up further loading of the same binaries.
21 * GDB in batch mode now exits with status 1 if the last command to be
24 * Changes to the "frame", "select-frame", and "info frame" CLI
25 commands. These commands all now take a frame specification which
26 is either a frame level, or one of the keywords 'level', 'address',
27 'function', or 'view' followed by a parameter. Selecting a frame by
28 address, or viewing a frame outside the current backtrace now
29 requires the use of a keyword. Selecting a frame by level is
30 unchanged. The MI comment "-stack-select-frame" is unchanged.
34 set debug compile-cplus-types
35 show debug compile-cplus-types
36 Control the display of debug output about type conversion in the
37 C++ compile feature. Commands have no effect while compiliong
42 Control whether debug output about files/functions skipping is
45 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
46 Apply a command to some frames.
47 FLAG arguments allow to control what output to produce and how to handle
48 errors raised when applying COMMAND to a frame.
51 Apply a command to all threads (ignoring errors and empty output).
52 Shortcut for 'thread apply all -s COMMAND'.
55 Apply a command to all frames (ignoring errors and empty output).
56 Shortcut for 'frame apply all -s COMMAND'.
59 Apply a command to all frames of all threads (ignoring errors and empty
61 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
63 maint set dwarf unwinders (on|off)
64 maint show dwarf unwinders
65 Control whether DWARF unwinders can be used.
68 Display a list of open files for a process.
72 target remote FILENAME
73 target extended-remote FILENAME
74 If FILENAME is a Unix domain socket, GDB will attempt to connect
75 to this socket instead of opening FILENAME as a character device.
77 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
78 The 'thread apply' command accepts new FLAG arguments.
79 FLAG arguments allow to control what output to produce and how to handle
80 errors raised when applying COMMAND to a thread.
84 ** The '-data-disassemble' MI command now accepts an '-a' option to
85 disassemble the whole function surrounding the given program
86 counter value or function name. Support for this feature can be
87 verified by using the "-list-features" command, which should
88 contain "data-disassemble-a-option".
90 ** Command responses and notifications that include a frame now include
91 the frame's architecture in a new "arch" attribute.
93 * New native configurations
95 GNU/Linux/RISC-V riscv*-*-linux*
99 GNU/Linux/RISC-V riscv*-*-linux*
101 CSKY GNU/LINUX csky*-*-linux
105 ** The gdb.Inferior type has a new 'progspace' property, which is the program
106 space associated to that inferior.
108 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
109 of objfiles associated to that program space.
111 *** Changes in GDB 8.2
113 * The 'set disassembler-options' command now supports specifying options
116 * The 'symbol-file' command now accepts an '-o' option to add a relative
117 offset to all sections.
119 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
120 a relative offset to all sections, but it allows to override the load
121 address of individual sections using '-s'.
123 * The 'add-symbol-file' command no longer requires the second argument
124 (address of the text section).
126 * The endianness used with the 'set endian auto' mode in the absence of
127 an executable selected for debugging is now the last endianness chosen
128 either by one of the 'set endian big' and 'set endian little' commands
129 or by inferring from the last executable used, rather than the startup
132 * The pager now allows a "c" response, meaning to disable the pager
133 for the rest of the current command.
135 * The commands 'info variables/functions/types' now show the source line
136 numbers of symbol definitions when available.
138 * 'info proc' now works on running processes on FreeBSD systems and core
139 files created on FreeBSD systems.
141 * C expressions can now use _Alignof, and C++ expressions can now use
144 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
145 the vector length while the process is running.
151 Control display of debugging info regarding the FreeBSD native target.
153 set|show varsize-limit
154 This new setting allows the user to control the maximum size of Ada
155 objects being printed when those objects have a variable type,
156 instead of that maximum size being hardcoded to 65536 bytes.
158 set|show record btrace cpu
159 Controls the processor to be used for enabling errata workarounds for
162 maint check libthread-db
163 Run integrity checks on the current inferior's thread debugging
166 maint set check-libthread-db (on|off)
167 maint show check-libthread-db
168 Control whether to run integrity checks on inferior specific thread
169 debugging libraries as they are loaded. The default is not to
174 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
176 ** The commands attached to a breakpoint can be set by assigning to
177 the breakpoint's "commands" field.
179 ** gdb.execute can now execute multi-line gdb commands.
181 ** The new functions gdb.convenience_variable and
182 gdb.set_convenience_variable can be used to get and set the value
183 of convenience variables.
185 ** A gdb.Parameter will no longer print the "set" help text on an
186 ordinary "set"; instead by default a "set" will be silent unless
187 the get_set_string method returns a non-empty string.
191 RiscV ELF riscv*-*-elf
193 * Removed targets and native configurations
195 m88k running OpenBSD m88*-*-openbsd*
196 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
197 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
198 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
200 * Aarch64/Linux hardware watchpoints improvements
202 Hardware watchpoints on unaligned addresses are now properly
203 supported when running Linux kernel 4.10 or higher: read and access
204 watchpoints are no longer spuriously missed, and all watchpoints
205 lengths between 1 and 8 bytes are supported. On older kernels,
206 watchpoints set on unaligned addresses are no longer missed, with
207 the tradeoff that there is a possibility of false hits being
212 --enable-codesign=CERT
213 This can be used to invoke "codesign -s CERT" after building gdb.
214 This option is useful on macOS, where code signing is required for
215 gdb to work properly.
217 --disable-gdbcli has been removed
218 This is now silently accepted, but does nothing.
220 *** Changes in GDB 8.1
222 * GDB now supports dynamically creating arbitrary register groups specified
223 in XML target descriptions. This allows for finer grain grouping of
224 registers on systems with a large amount of registers.
226 * The 'ptype' command now accepts a '/o' flag, which prints the
227 offsets and sizes of fields in a struct, like the pahole(1) tool.
229 * New "--readnever" command line option instructs GDB to not read each
230 symbol file's symbolic debug information. This makes startup faster
231 but at the expense of not being able to perform symbolic debugging.
232 This option is intended for use cases where symbolic debugging will
233 not be used, e.g., when you only need to dump the debuggee's core.
235 * GDB now uses the GNU MPFR library, if available, to emulate target
236 floating-point arithmetic during expression evaluation when the target
237 uses different floating-point formats than the host. At least version
238 3.1 of GNU MPFR is required.
240 * GDB now supports access to the guarded-storage-control registers and the
241 software-based guarded-storage broadcast control registers on IBM z14.
243 * On Unix systems, GDB now supports transmitting environment variables
244 that are to be set or unset to GDBserver. These variables will
245 affect the environment to be passed to the remote inferior.
247 To inform GDB of environment variables that are to be transmitted to
248 GDBserver, use the "set environment" command. Only user set
249 environment variables are sent to GDBserver.
251 To inform GDB of environment variables that are to be unset before
252 the remote inferior is started by the GDBserver, use the "unset
253 environment" command.
255 * Completion improvements
257 ** GDB can now complete function parameters in linespecs and
258 explicit locations without quoting. When setting breakpoints,
259 quoting around functions names to help with TAB-completion is
260 generally no longer necessary. For example, this now completes
263 (gdb) b function(in[TAB]
264 (gdb) b function(int)
266 Related, GDB is no longer confused with completing functions in
267 C++ anonymous namespaces:
270 (gdb) b (anonymous namespace)::[TAB][TAB]
271 (anonymous namespace)::a_function()
272 (anonymous namespace)::b_function()
274 ** GDB now has much improved linespec and explicit locations TAB
275 completion support, that better understands what you're
276 completing and offers better suggestions. For example, GDB no
277 longer offers data symbols as possible completions when you're
278 setting a breakpoint.
280 ** GDB now TAB-completes label symbol names.
282 ** The "complete" command now mimics TAB completion accurately.
284 * New command line options (gcore)
287 Dump all memory mappings.
289 * Breakpoints on C++ functions are now set on all scopes by default
291 By default, breakpoints on functions/methods are now interpreted as
292 specifying all functions with the given name ignoring missing
293 leading scopes (namespaces and classes).
295 For example, assuming a C++ program with symbols named:
300 both commands "break func()" and "break B::func()" set a breakpoint
303 You can use the new flag "-qualified" to override this. This makes
304 GDB interpret the specified function name as a complete
305 fully-qualified name instead. For example, using the same C++
306 program, the "break -q B::func" command sets a breakpoint on
307 "B::func", only. A parameter has been added to the Python
308 gdb.Breakpoint constructor to achieve the same result when creating
309 a breakpoint from Python.
311 * Breakpoints on functions marked with C++ ABI tags
313 GDB can now set breakpoints on functions marked with C++ ABI tags
314 (e.g., [abi:cxx11]). See here for a description of ABI tags:
315 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
317 Functions with a C++11 abi tag are demangled/displayed like this:
319 function[abi:cxx11](int)
322 You can now set a breakpoint on such functions simply as if they had
325 (gdb) b function(int)
327 Or if you need to disambiguate between tags, like:
329 (gdb) b function[abi:other_tag](int)
331 Tab completion was adjusted accordingly as well.
335 ** New events gdb.new_inferior, gdb.inferior_deleted, and
336 gdb.new_thread are emitted. See the manual for further
337 description of these.
339 ** A new function, "gdb.rbreak" has been added to the Python API.
340 This function allows the setting of a large number of breakpoints
341 via a regex pattern in Python. See the manual for further details.
343 ** Python breakpoints can now accept explicit locations. See the
344 manual for a further description of this feature.
347 * New features in the GDB remote stub, GDBserver
349 ** GDBserver is now able to start inferior processes with a
350 specified initial working directory.
352 The user can set the desired working directory to be used from
353 GDB using the new "set cwd" command.
355 ** New "--selftest" command line option runs some GDBserver self
356 tests. These self tests are disabled in releases.
358 ** On Unix systems, GDBserver now does globbing expansion and variable
359 substitution in inferior command line arguments.
361 This is done by starting inferiors using a shell, like GDB does.
362 See "set startup-with-shell" in the user manual for how to disable
363 this from GDB when using "target extended-remote". When using
364 "target remote", you can disable the startup with shell by using the
365 new "--no-startup-with-shell" GDBserver command line option.
367 ** On Unix systems, GDBserver now supports receiving environment
368 variables that are to be set or unset from GDB. These variables
369 will affect the environment to be passed to the inferior.
371 * When catching an Ada exception raised with a message, GDB now prints
372 the message in the catchpoint hit notification. In GDB/MI mode, that
373 information is provided as an extra field named "exception-message"
374 in the *stopped notification.
376 * Trait objects can now be inspected When debugging Rust code. This
377 requires compiler support which will appear in Rust 1.24.
381 QEnvironmentHexEncoded
382 Inform GDBserver of an environment variable that is to be passed to
383 the inferior when starting it.
386 Inform GDBserver of an environment variable that is to be unset
387 before starting the remote inferior.
390 Inform GDBserver that the environment should be reset (i.e.,
391 user-set environment variables should be unset).
394 Indicates whether the inferior must be started with a shell or not.
397 Tell GDBserver that the inferior to be started should use a specific
400 * The "maintenance print c-tdesc" command now takes an optional
401 argument which is the file name of XML target description.
403 * The "maintenance selftest" command now takes an optional argument to
404 filter the tests to be run.
406 * The "enable", and "disable" commands now accept a range of
407 breakpoint locations, e.g. "enable 1.3-5".
412 Set and show the current working directory for the inferior.
415 Set and show compilation command used for compiling and injecting code
416 with the 'compile' commands.
418 set debug separate-debug-file
419 show debug separate-debug-file
420 Control the display of debug output about separate debug file search.
422 set dump-excluded-mappings
423 show dump-excluded-mappings
424 Control whether mappings marked with the VM_DONTDUMP flag should be
425 dumped when generating a core file.
428 List the registered selftests.
431 Start the debugged program stopping at the first instruction.
434 Control display of debugging messages related to OpenRISC targets.
436 set|show print type nested-type-limit
437 Set and show the limit of nesting level for nested types that the
438 type printer will show.
440 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
443 * Safer/improved support for debugging with no debug info
445 GDB no longer assumes functions with no debug information return
448 This means that GDB now refuses to call such functions unless you
449 tell it the function's type, by either casting the call to the
450 declared return type, or by casting the function to a function
451 pointer of the right type, and calling that:
453 (gdb) p getenv ("PATH")
454 'getenv' has unknown return type; cast the call to its declared return type
455 (gdb) p (char *) getenv ("PATH")
456 $1 = 0x7fffffffe "/usr/local/bin:/"...
457 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
458 $2 = 0x7fffffffe "/usr/local/bin:/"...
460 Similarly, GDB no longer assumes that global variables with no debug
461 info have type 'int', and refuses to print the variable's value
462 unless you tell it the variable's type:
465 'var' has unknown type; cast it to its declared type
469 * New native configurations
471 FreeBSD/aarch64 aarch64*-*-freebsd*
472 FreeBSD/arm arm*-*-freebsd*
476 FreeBSD/aarch64 aarch64*-*-freebsd*
477 FreeBSD/arm arm*-*-freebsd*
478 OpenRISC ELF or1k*-*-elf
480 * Removed targets and native configurations
482 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
484 *** Changes in GDB 8.0
486 * GDB now supports access to the PKU register on GNU/Linux. The register is
487 added by the Memory Protection Keys for Userspace feature which will be
488 available in future Intel CPUs.
490 * GDB now supports C++11 rvalue references.
494 ** New functions to start, stop and access a running btrace recording.
495 ** Rvalue references are now supported in gdb.Type.
497 * GDB now supports recording and replaying rdrand and rdseed Intel 64
500 * Building GDB and GDBserver now requires a C++11 compiler.
502 For example, GCC 4.8 or later.
504 It is no longer possible to build GDB or GDBserver with a C
505 compiler. The --disable-build-with-cxx configure option has been
508 * Building GDB and GDBserver now requires GNU make >= 3.81.
510 It is no longer supported to build GDB or GDBserver with another
511 implementation of the make program or an earlier version of GNU make.
513 * Native debugging on MS-Windows supports command-line redirection
515 Command-line arguments used for starting programs on MS-Windows can
516 now include redirection symbols supported by native Windows shells,
517 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
518 as "run", "start", and "set args", as well as the corresponding MI
521 * Support for thread names on MS-Windows.
523 GDB now catches and handles the special exception that programs
524 running on MS-Windows use to assign names to threads in the
527 * Support for Java programs compiled with gcj has been removed.
529 * User commands now accept an unlimited number of arguments.
530 Previously, only up to 10 was accepted.
532 * The "eval" command now expands user-defined command arguments.
534 This makes it easier to process a variable number of arguments:
539 eval "print $arg%d", $i
544 * Target descriptions can now describe registers for sparc32 and sparc64.
546 * GDB now supports DWARF version 5 (debug information format).
547 Its .debug_names index is not yet supported.
549 * New native configurations
551 FreeBSD/mips mips*-*-freebsd
555 Synopsys ARC arc*-*-elf32
556 FreeBSD/mips mips*-*-freebsd
558 * Removed targets and native configurations
560 Alpha running FreeBSD alpha*-*-freebsd*
561 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
566 Erases all the flash memory regions reported by the target.
568 maint print arc arc-instruction address
569 Print internal disassembler information about instruction at a given address.
573 set disassembler-options
574 show disassembler-options
575 Controls the passing of target specific information to the disassembler.
576 If it is necessary to specify more than one disassembler option then
577 multiple options can be placed together into a comma separated list.
578 The default value is the empty string. Currently, the only supported
579 targets are ARM, PowerPC and S/390.
584 Erases all the flash memory regions reported by the target. This is
585 equivalent to the CLI command flash-erase.
587 -file-list-shared-libraries
588 List the shared libraries in the program. This is
589 equivalent to the CLI command "info shared".
592 Catchpoints stopping the program when Ada exceptions are
593 handled. This is equivalent to the CLI command "catch handlers".
595 *** Changes in GDB 7.12
597 * GDB and GDBserver now build with a C++ compiler by default.
599 The --enable-build-with-cxx configure option is now enabled by
600 default. One must now explicitly configure with
601 --disable-build-with-cxx in order to build with a C compiler. This
602 option will be removed in a future release.
604 * GDBserver now supports recording btrace without maintaining an active
607 * GDB now supports a negative repeat count in the 'x' command to examine
608 memory backward from the given address. For example:
611 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
612 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
613 (gdb) x/-5i 0x0000000000400580
614 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
615 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
616 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
617 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
618 0x40057b <main(int, char**)+25>:
619 callq 0x400536 <Func1(int, char const*)>
621 * Fortran: Support structures with fields of dynamic types and
622 arrays of dynamic types.
624 * The symbol dumping maintenance commands have new syntax.
625 maint print symbols [-pc address] [--] [filename]
626 maint print symbols [-objfile objfile] [-source source] [--] [filename]
627 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
628 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
629 maint print msymbols [-objfile objfile] [--] [filename]
631 * GDB now supports multibit bitfields and enums in target register
634 * New Python-based convenience function $_as_string(val), which returns
635 the textual representation of a value. This function is especially
636 useful to obtain the text label of an enum value.
638 * Intel MPX bound violation handling.
640 Segmentation faults caused by a Intel MPX boundary violation
641 now display the kind of violation (upper or lower), the memory
642 address accessed and the memory bounds, along with the usual
643 signal received and code location.
647 Program received signal SIGSEGV, Segmentation fault
648 Upper bound violation while accessing address 0x7fffffffc3b3
649 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
650 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
652 * Rust language support.
653 GDB now supports debugging programs written in the Rust programming
654 language. See https://www.rust-lang.org/ for more information about
657 * Support for running interpreters on specified input/output devices
659 GDB now supports a new mechanism that allows frontends to provide
660 fully featured GDB console views, as a better alternative to
661 building such views on top of the "-interpreter-exec console"
662 command. See the new "new-ui" command below. With that command,
663 frontends can now start GDB in the traditional command-line mode
664 running in an embedded terminal emulator widget, and create a
665 separate MI interpreter running on a specified i/o device. In this
666 way, GDB handles line editing, history, tab completion, etc. in the
667 console all by itself, and the GUI uses the separate MI interpreter
668 for its own control and synchronization, invisible to the command
671 * The "catch syscall" command catches groups of related syscalls.
673 The "catch syscall" command now supports catching a group of related
674 syscalls using the 'group:' or 'g:' prefix.
679 skip -gfile file-glob-pattern
680 skip -function function
681 skip -rfunction regular-expression
682 A generalized form of the skip command, with new support for
683 glob-style file names and regular expressions for function names.
684 Additionally, a file spec and a function spec may now be combined.
686 maint info line-table REGEXP
687 Display the contents of GDB's internal line table data struture.
690 Run any GDB unit tests that were compiled in.
693 Start a new user interface instance running INTERP as interpreter,
694 using the TTY file for input/output.
698 ** gdb.Breakpoint objects have a new attribute "pending", which
699 indicates whether the breakpoint is pending.
700 ** Three new breakpoint-related events have been added:
701 gdb.breakpoint_created, gdb.breakpoint_modified, and
702 gdb.breakpoint_deleted.
705 Signal ("set") the given MS-Windows event object. This is used in
706 conjunction with the Windows JIT debugging (AeDebug) support, where
707 the OS suspends a crashing process until a debugger can attach to
708 it. Resuming the crashing process, in order to debug it, is done by
711 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
712 was added in GDBserver, including JIT compiling fast tracepoint's
713 conditional expression bytecode into native code.
715 * Support for various remote target protocols and ROM monitors has
718 target m32rsdi Remote M32R debugging over SDI
719 target mips MIPS remote debugging protocol
720 target pmon PMON ROM monitor
721 target ddb NEC's DDB variant of PMON for Vr4300
722 target rockhopper NEC RockHopper variant of PMON
723 target lsi LSI variant of PMO
725 * Support for tracepoints and fast tracepoints on powerpc-linux,
726 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
727 including JIT compiling fast tracepoint's conditional expression
728 bytecode into native code.
730 * MI async record =record-started now includes the method and format used for
731 recording. For example:
733 =record-started,thread-group="i1",method="btrace",format="bts"
735 * MI async record =thread-selected now includes the frame field. For example:
737 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
741 Andes NDS32 nds32*-*-elf
743 *** Changes in GDB 7.11
745 * GDB now supports debugging kernel-based threads on FreeBSD.
747 * Per-inferior thread numbers
749 Thread numbers are now per inferior instead of global. If you're
750 debugging multiple inferiors, GDB displays thread IDs using a
751 qualified INF_NUM.THR_NUM form. For example:
755 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
756 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
757 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
758 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
760 As consequence, thread numbers as visible in the $_thread
761 convenience variable and in Python's InferiorThread.num attribute
762 are no longer unique between inferiors.
764 GDB now maintains a second thread ID per thread, referred to as the
765 global thread ID, which is the new equivalent of thread numbers in
766 previous releases. See also $_gthread below.
768 For backwards compatibility, MI's thread IDs always refer to global
771 * Commands that accept thread IDs now accept the qualified
772 INF_NUM.THR_NUM form as well. For example:
775 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
778 * In commands that accept a list of thread IDs, you can now refer to
779 all threads of an inferior using a star wildcard. GDB accepts
780 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
781 refer to all threads of the current inferior. For example, "info
784 * You can use "info threads -gid" to display the global thread ID of
787 * The new convenience variable $_gthread holds the global number of
790 * The new convenience variable $_inferior holds the number of the
793 * GDB now displays the ID and name of the thread that hit a breakpoint
794 or received a signal, if your program is multi-threaded. For
797 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
798 Thread 1 "main" received signal SIGINT, Interrupt.
800 * Record btrace now supports non-stop mode.
802 * Support for tracepoints on aarch64-linux was added in GDBserver.
804 * The 'record instruction-history' command now indicates speculative execution
805 when using the Intel Processor Trace recording format.
807 * GDB now allows users to specify explicit locations, bypassing
808 the linespec parser. This feature is also available to GDB/MI
811 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
812 GDB now is able to debug both AArch64 applications and ARM applications
815 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
816 including JIT compiling fast tracepoint's conditional expression bytecode
819 * GDB now supports displaced stepping on AArch64 GNU/Linux.
821 * "info threads", "info inferiors", "info display", "info checkpoints"
822 and "maint info program-spaces" now list the corresponding items in
823 ascending ID order, for consistency with all other "info" commands.
825 * In Ada, the overloads selection menu has been enhanced to display the
826 parameter types and the return types for the matching overloaded subprograms.
830 maint set target-non-stop (on|off|auto)
831 maint show target-non-stop
832 Control whether GDB targets always operate in non-stop mode even if
833 "set non-stop" is "off". The default is "auto", meaning non-stop
834 mode is enabled if supported by the target.
836 maint set bfd-sharing
837 maint show bfd-sharing
838 Control the reuse of bfd objects.
842 Control display of debugging info regarding bfd caching.
846 Control display of debugging info regarding FreeBSD threads.
848 set remote multiprocess-extensions-packet
849 show remote multiprocess-extensions-packet
850 Set/show the use of the remote protocol multiprocess extensions.
852 set remote thread-events
853 show remote thread-events
854 Set/show the use of thread create/exit events.
856 set ada print-signatures on|off
857 show ada print-signatures"
858 Control whether parameter types and return types are displayed in overloads
859 selection menus. It is activaled (@code{on}) by default.
863 Controls the maximum size of memory, in bytes, that GDB will
864 allocate for value contents. Prevents incorrect programs from
865 causing GDB to allocate overly large buffers. Default is 64k.
867 * The "disassemble" command accepts a new modifier: /s.
868 It prints mixed source+disassembly like /m with two differences:
869 - disassembled instructions are now printed in program order, and
870 - and source for all relevant files is now printed.
871 The "/m" option is now considered deprecated: its "source-centric"
872 output hasn't proved useful in practice.
874 * The "record instruction-history" command accepts a new modifier: /s.
875 It behaves exactly like /m and prints mixed source+disassembly.
877 * The "set scheduler-locking" command supports a new mode "replay".
878 It behaves like "off" in record mode and like "on" in replay mode.
880 * Support for various ROM monitors has been removed:
882 target dbug dBUG ROM monitor for Motorola ColdFire
883 target picobug Motorola picobug monitor
884 target dink32 DINK32 ROM monitor for PowerPC
885 target m32r Renesas M32R/D ROM monitor
886 target mon2000 mon2000 ROM monitor
887 target ppcbug PPCBUG ROM monitor for PowerPC
889 * Support for reading/writing memory and extracting values on architectures
890 whose memory is addressable in units of any integral multiple of 8 bits.
893 Allows to break when an Ada exception is handled.
898 Indicates that an exec system call was executed.
900 exec-events feature in qSupported
901 The qSupported packet allows GDB to request support for exec
902 events using the new 'gdbfeature' exec-event, and the qSupported
903 response can contain the corresponding 'stubfeature'. Set and
904 show commands can be used to display whether these features are enabled.
907 Equivalent to interrupting with the ^C character, but works in
910 thread created stop reason (T05 create:...)
911 Indicates that the thread was just created and is stopped at entry.
913 thread exit stop reply (w exitcode;tid)
914 Indicates that the thread has terminated.
917 Enables/disables thread create and exit event reporting. For
918 example, this is used in non-stop mode when GDB stops a set of
919 threads and synchronously waits for the their corresponding stop
920 replies. Without exit events, if one of the threads exits, GDB
921 would hang forever not knowing that it should no longer expect a
922 stop for that same thread.
925 Indicates that there are no resumed threads left in the target (all
926 threads are stopped). The remote stub reports support for this stop
927 reply to GDB's qSupported query.
930 Enables/disables catching syscalls from the inferior process.
931 The remote stub reports support for this packet to GDB's qSupported query.
933 syscall_entry stop reason
934 Indicates that a syscall was just called.
936 syscall_return stop reason
937 Indicates that a syscall just returned.
939 * Extended-remote exec events
941 ** GDB now has support for exec events on extended-remote Linux targets.
942 For such targets with Linux kernels 2.5.46 and later, this enables
943 follow-exec-mode and exec catchpoints.
945 set remote exec-event-feature-packet
946 show remote exec-event-feature-packet
947 Set/show the use of the remote exec event feature.
949 * Thread names in remote protocol
951 The reply to qXfer:threads:read may now include a name attribute for each
954 * Target remote mode fork and exec events
956 ** GDB now has support for fork and exec events on target remote mode
957 Linux targets. For such targets with Linux kernels 2.5.46 and later,
958 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
959 fork and exec catchpoints.
961 * Remote syscall events
963 ** GDB now has support for catch syscall on remote Linux targets,
964 currently enabled on x86/x86_64 architectures.
966 set remote catch-syscall-packet
967 show remote catch-syscall-packet
968 Set/show the use of the remote catch syscall feature.
972 ** The -var-set-format command now accepts the zero-hexadecimal
973 format. It outputs data in hexadecimal format with zero-padding on the
978 ** gdb.InferiorThread objects have a new attribute "global_num",
979 which refers to the thread's global thread ID. The existing
980 "num" attribute now refers to the thread's per-inferior number.
981 See "Per-inferior thread numbers" above.
982 ** gdb.InferiorThread objects have a new attribute "inferior", which
983 is the Inferior object the thread belongs to.
985 *** Changes in GDB 7.10
987 * Support for process record-replay and reverse debugging on aarch64*-linux*
988 targets has been added. GDB now supports recording of A64 instruction set
989 including advance SIMD instructions.
991 * Support for Sun's version of the "stabs" debug file format has been removed.
993 * GDB now honors the content of the file /proc/PID/coredump_filter
994 (PID is the process ID) on GNU/Linux systems. This file can be used
995 to specify the types of memory mappings that will be included in a
996 corefile. For more information, please refer to the manual page of
997 "core(5)". GDB also has a new command: "set use-coredump-filter
998 on|off". It allows to set whether GDB will read the content of the
999 /proc/PID/coredump_filter file when generating a corefile.
1001 * The "info os" command on GNU/Linux can now display information on
1003 "info os cpus" Listing of all cpus/cores on the system
1005 * GDB has two new commands: "set serial parity odd|even|none" and
1006 "show serial parity". These allows to set or show parity for the
1009 * The "info source" command now displays the producer string if it was
1010 present in the debug info. This typically includes the compiler version
1011 and may include things like its command line arguments.
1013 * The "info dll", an alias of the "info sharedlibrary" command,
1014 is now available on all platforms.
1016 * Directory names supplied to the "set sysroot" commands may be
1017 prefixed with "target:" to tell GDB to access shared libraries from
1018 the target system, be it local or remote. This replaces the prefix
1019 "remote:". The default sysroot has been changed from "" to
1020 "target:". "remote:" is automatically converted to "target:" for
1021 backward compatibility.
1023 * The system root specified by "set sysroot" will be prepended to the
1024 filename of the main executable (if reported to GDB as absolute by
1025 the operating system) when starting processes remotely, and when
1026 attaching to already-running local or remote processes.
1028 * GDB now supports automatic location and retrieval of executable
1029 files from remote targets. Remote debugging can now be initiated
1030 using only a "target remote" or "target extended-remote" command
1031 (no "set sysroot" or "file" commands are required). See "New remote
1034 * The "dump" command now supports verilog hex format.
1036 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1038 * On GNU/Linux, GDB and gdbserver are now able to access executable
1039 and shared library files without a "set sysroot" command when
1040 attaching to processes running in different mount namespaces from
1041 the debugger. This makes it possible to attach to processes in
1042 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1043 See "New remote packets" below.
1045 * The "tui reg" command now provides completion for all of the
1046 available register groups, including target specific groups.
1048 * The HISTSIZE environment variable is no longer read when determining
1049 the size of GDB's command history. GDB now instead reads the dedicated
1050 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1051 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1056 ** Memory ports can now be unbuffered.
1060 ** gdb.Objfile objects have a new attribute "username",
1061 which is the name of the objfile as specified by the user,
1062 without, for example, resolving symlinks.
1063 ** You can now write frame unwinders in Python.
1064 ** gdb.Type objects have a new method "optimized_out",
1065 returning optimized out gdb.Value instance of this type.
1066 ** gdb.Value objects have new methods "reference_value" and
1067 "const_value" which return a reference to the value and a
1068 "const" version of the value respectively.
1072 maint print symbol-cache
1073 Print the contents of the symbol cache.
1075 maint print symbol-cache-statistics
1076 Print statistics of symbol cache usage.
1078 maint flush-symbol-cache
1079 Flush the contents of the symbol cache.
1083 Start branch trace recording using Branch Trace Store (BTS) format.
1086 Evaluate expression by using the compiler and print result.
1090 Explicit commands for enabling and disabling tui mode.
1093 set mpx bound on i386 and amd64
1094 Support for bound table investigation on Intel MPX enabled applications.
1098 Start branch trace recording using Intel Processor Trace format.
1101 Print information about branch tracing internals.
1103 maint btrace packet-history
1104 Print the raw branch tracing data.
1106 maint btrace clear-packet-history
1107 Discard the stored raw branch tracing data.
1110 Discard all branch tracing data. It will be fetched and processed
1111 anew by the next "record" command.
1116 Renamed from "set debug dwarf2-die".
1117 show debug dwarf-die
1118 Renamed from "show debug dwarf2-die".
1120 set debug dwarf-read
1121 Renamed from "set debug dwarf2-read".
1122 show debug dwarf-read
1123 Renamed from "show debug dwarf2-read".
1125 maint set dwarf always-disassemble
1126 Renamed from "maint set dwarf2 always-disassemble".
1127 maint show dwarf always-disassemble
1128 Renamed from "maint show dwarf2 always-disassemble".
1130 maint set dwarf max-cache-age
1131 Renamed from "maint set dwarf2 max-cache-age".
1132 maint show dwarf max-cache-age
1133 Renamed from "maint show dwarf2 max-cache-age".
1135 set debug dwarf-line
1136 show debug dwarf-line
1137 Control display of debugging info regarding DWARF line processing.
1140 show max-completions
1141 Set the maximum number of candidates to be considered during
1142 completion. The default value is 200. This limit allows GDB
1143 to avoid generating large completion lists, the computation of
1144 which can cause the debugger to become temporarily unresponsive.
1146 set history remove-duplicates
1147 show history remove-duplicates
1148 Control the removal of duplicate history entries.
1150 maint set symbol-cache-size
1151 maint show symbol-cache-size
1152 Control the size of the symbol cache.
1154 set|show record btrace bts buffer-size
1155 Set and show the size of the ring buffer used for branch tracing in
1157 The obtained size may differ from the requested size. Use "info
1158 record" to see the obtained buffer size.
1160 set debug linux-namespaces
1161 show debug linux-namespaces
1162 Control display of debugging info regarding Linux namespaces.
1164 set|show record btrace pt buffer-size
1165 Set and show the size of the ring buffer used for branch tracing in
1166 Intel Processor Trace format.
1167 The obtained size may differ from the requested size. Use "info
1168 record" to see the obtained buffer size.
1170 maint set|show btrace pt skip-pad
1171 Set and show whether PAD packets are skipped when computing the
1174 * The command 'thread apply all' can now support new option '-ascending'
1175 to call its specified command for all threads in ascending order.
1177 * Python/Guile scripting
1179 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1180 special section named `.debug_gdb_scripts'.
1182 * New remote packets
1184 qXfer:btrace-conf:read
1185 Return the branch trace configuration for the current thread.
1187 Qbtrace-conf:bts:size
1188 Set the requested ring buffer size for branch tracing in BTS format.
1191 Enable Intel Procesor Trace-based branch tracing for the current
1192 process. The remote stub reports support for this packet to GDB's
1195 Qbtrace-conf:pt:size
1196 Set the requested ring buffer size for branch tracing in Intel Processor
1200 Indicates a memory breakpoint instruction was executed, irrespective
1201 of whether it was GDB that planted the breakpoint or the breakpoint
1202 is hardcoded in the program. This is required for correct non-stop
1206 Indicates the target stopped for a hardware breakpoint. This is
1207 required for correct non-stop mode operation.
1210 Return information about files on the remote system.
1212 qXfer:exec-file:read
1213 Return the full absolute name of the file that was executed to
1214 create a process running on the remote system.
1217 Select the filesystem on which vFile: operations with filename
1218 arguments will operate. This is required for GDB to be able to
1219 access files on remote targets where the remote stub does not
1220 share a common filesystem with the inferior(s).
1223 Indicates that a fork system call was executed.
1226 Indicates that a vfork system call was executed.
1228 vforkdone stop reason
1229 Indicates that a vfork child of the specified process has executed
1230 an exec or exit, allowing the vfork parent to resume execution.
1232 fork-events and vfork-events features in qSupported
1233 The qSupported packet allows GDB to request support for fork and
1234 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1235 and the qSupported response can contain the corresponding
1236 'stubfeatures'. Set and show commands can be used to display
1237 whether these features are enabled.
1239 * Extended-remote fork events
1241 ** GDB now has support for fork events on extended-remote Linux
1242 targets. For targets with Linux kernels 2.5.60 and later, this
1243 enables follow-fork-mode and detach-on-fork for both fork and
1244 vfork, as well as fork and vfork catchpoints.
1246 * The info record command now shows the recording format and the
1247 branch tracing configuration for the current thread when using
1248 the btrace record target.
1249 For the BTS format, it shows the ring buffer size.
1251 * GDB now has support for DTrace USDT (Userland Static Defined
1252 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1254 * GDB now supports access to vector registers on S/390 GNU/Linux
1257 * Removed command line options
1259 -xdb HP-UX XDB compatibility mode.
1261 * Removed targets and native configurations
1263 HP/PA running HP-UX hppa*-*-hpux*
1264 Itanium running HP-UX ia64-*-hpux*
1266 * New configure options
1269 This configure option allows the user to build GDB with support for
1270 Intel Processor Trace (default: auto). This requires libipt.
1272 --with-libipt-prefix=PATH
1273 Specify the path to the version of libipt that GDB should use.
1274 $PATH/include should contain the intel-pt.h header and
1275 $PATH/lib should contain the libipt.so library.
1277 *** Changes in GDB 7.9.1
1281 ** Xmethods can now specify a result type.
1283 *** Changes in GDB 7.9
1285 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1289 ** You can now access frame registers from Python scripts.
1290 ** New attribute 'producer' for gdb.Symtab objects.
1291 ** gdb.Objfile objects have a new attribute "progspace",
1292 which is the gdb.Progspace object of the containing program space.
1293 ** gdb.Objfile objects have a new attribute "owner".
1294 ** gdb.Objfile objects have a new attribute "build_id",
1295 which is the build ID generated when the file was built.
1296 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1297 ** A new event "gdb.clear_objfiles" has been added, triggered when
1298 selecting a new file to debug.
1299 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1300 ** New function gdb.lookup_objfile.
1302 New events which are triggered when GDB modifies the state of the
1305 ** gdb.events.inferior_call_pre: Function call is about to be made.
1306 ** gdb.events.inferior_call_post: Function call has just been made.
1307 ** gdb.events.memory_changed: A memory location has been altered.
1308 ** gdb.events.register_changed: A register has been altered.
1310 * New Python-based convenience functions:
1312 ** $_caller_is(name [, number_of_frames])
1313 ** $_caller_matches(regexp [, number_of_frames])
1314 ** $_any_caller_is(name [, number_of_frames])
1315 ** $_any_caller_matches(regexp [, number_of_frames])
1317 * GDB now supports the compilation and injection of source code into
1318 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1319 to compile the source code to object code, and if successful, inject
1320 and execute that code within the current context of the inferior.
1321 Currently the C language is supported. The commands used to
1322 interface with this new feature are:
1324 compile code [-raw|-r] [--] [source code]
1325 compile file [-raw|-r] filename
1329 demangle [-l language] [--] name
1330 Demangle "name" in the specified language, or the current language
1331 if elided. This command is renamed from the "maint demangle" command.
1332 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1333 as "maint demangler-warning".
1335 queue-signal signal-name-or-number
1336 Queue a signal to be delivered to the thread when it is resumed.
1338 add-auto-load-scripts-directory directory
1339 Add entries to the list of directories from which to load auto-loaded
1342 maint print user-registers
1343 List all currently available "user" registers.
1345 compile code [-r|-raw] [--] [source code]
1346 Compile, inject, and execute in the inferior the executable object
1347 code produced by compiling the provided source code.
1349 compile file [-r|-raw] filename
1350 Compile and inject into the inferior the executable object code
1351 produced by compiling the source code stored in the filename
1354 * On resume, GDB now always passes the signal the program had stopped
1355 for to the thread the signal was sent to, even if the user changed
1356 threads before resuming. Previously GDB would often (but not
1357 always) deliver the signal to the thread that happens to be current
1360 * Conversely, the "signal" command now consistently delivers the
1361 requested signal to the current thread. GDB now asks for
1362 confirmation if the program had stopped for a signal and the user
1363 switched threads meanwhile.
1365 * "breakpoint always-inserted" modes "off" and "auto" merged.
1367 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1368 won't remove breakpoints from the target until all threads stop,
1369 even in non-stop mode. The "auto" mode has been removed, and "off"
1370 is now the default mode.
1374 set debug symbol-lookup
1375 show debug symbol-lookup
1376 Control display of debugging info regarding symbol lookup.
1380 ** The -list-thread-groups command outputs an exit-code field for
1381 inferiors that have exited.
1385 MIPS SDE mips*-sde*-elf*
1389 Support for these obsolete configurations has been removed.
1391 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1392 SGI Irix-5.x mips-*-irix5*
1393 SGI Irix-6.x mips-*-irix6*
1394 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1395 VAX running Ultrix vax-*-ultrix*
1397 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1398 and "assf"), have been removed. Use the "sharedlibrary" command, or
1399 its alias "share", instead.
1401 *** Changes in GDB 7.8
1403 * New command line options
1406 This is an alias for the --data-directory option.
1408 * GDB supports printing and modifying of variable length automatic arrays
1409 as specified in ISO C99.
1411 * The ARM simulator now supports instruction level tracing
1412 with or without disassembly.
1416 GDB now has support for scripting using Guile. Whether this is
1417 available is determined at configure time.
1418 Guile version 2.0 or greater is required.
1419 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1421 * New commands (for set/show, see "New options" below)
1425 Invoke CODE by passing it to the Guile interpreter.
1429 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1431 info auto-load guile-scripts [regexp]
1432 Print the list of automatically loaded Guile scripts.
1434 * The source command is now capable of sourcing Guile scripts.
1435 This feature is dependent on the debugger being built with Guile support.
1439 set print symbol-loading (off|brief|full)
1440 show print symbol-loading
1441 Control whether to print informational messages when loading symbol
1442 information for a file. The default is "full", but when debugging
1443 programs with large numbers of shared libraries the amount of output
1444 becomes less useful.
1446 set guile print-stack (none|message|full)
1447 show guile print-stack
1448 Show a stack trace when an error is encountered in a Guile script.
1450 set auto-load guile-scripts (on|off)
1451 show auto-load guile-scripts
1452 Control auto-loading of Guile script files.
1454 maint ada set ignore-descriptive-types (on|off)
1455 maint ada show ignore-descriptive-types
1456 Control whether the debugger should ignore descriptive types in Ada
1457 programs. The default is not to ignore the descriptive types. See
1458 the user manual for more details on descriptive types and the intended
1459 usage of this option.
1461 set auto-connect-native-target
1463 Control whether GDB is allowed to automatically connect to the
1464 native target for the run, attach, etc. commands when not connected
1465 to any target yet. See also "target native" below.
1467 set record btrace replay-memory-access (read-only|read-write)
1468 show record btrace replay-memory-access
1469 Control what memory accesses are allowed during replay.
1471 maint set target-async (on|off)
1472 maint show target-async
1473 This controls whether GDB targets operate in synchronous or
1474 asynchronous mode. Normally the default is asynchronous, if it is
1475 available; but this can be changed to more easily debug problems
1476 occurring only in synchronous mode.
1478 set mi-async (on|off)
1480 Control whether MI asynchronous mode is preferred. This supersedes
1481 "set target-async" of previous GDB versions.
1483 * "set target-async" is deprecated as a CLI option and is now an alias
1484 for "set mi-async" (only puts MI into async mode).
1486 * Background execution commands (e.g., "c&", "s&", etc.) are now
1487 possible ``out of the box'' if the target supports them. Previously
1488 the user would need to explicitly enable the possibility with the
1489 "set target-async on" command.
1491 * New features in the GDB remote stub, GDBserver
1493 ** New option --debug-format=option1[,option2,...] allows one to add
1494 additional text to each output. At present only timestamps
1495 are supported: --debug-format=timestamps.
1496 Timestamps can also be turned on with the
1497 "monitor set debug-format timestamps" command from GDB.
1499 * The 'record instruction-history' command now starts counting instructions
1500 at one. This also affects the instruction ranges reported by the
1501 'record function-call-history' command when given the /i modifier.
1503 * The command 'record function-call-history' supports a new modifier '/c' to
1504 indent the function names based on their call stack depth.
1505 The fields for the '/i' and '/l' modifier have been reordered.
1506 The source line range is now prefixed with 'at'.
1507 The instruction range is now prefixed with 'inst'.
1508 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1509 "record instruction-history" and "list" commands.
1511 * The ranges given as arguments to the 'record function-call-history' and
1512 'record instruction-history' commands are now inclusive.
1514 * The btrace record target now supports the 'record goto' command.
1515 For locations inside the execution trace, the back trace is computed
1516 based on the information stored in the execution trace.
1518 * The btrace record target supports limited reverse execution and replay.
1519 The target does not record data and therefore does not allow reading
1520 memory or registers.
1522 * The "catch syscall" command now works on s390*-linux* targets.
1524 * The "compare-sections" command is no longer specific to target
1525 remote. It now works with all targets.
1527 * All native targets are now consistently called "native".
1528 Consequently, the "target child", "target GNU", "target djgpp",
1529 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1530 commands have been replaced with "target native". The QNX/NTO port
1531 leaves the "procfs" target in place and adds a "native" target for
1532 consistency with other ports. The impact on users should be minimal
1533 as these commands previously either throwed an error, or were
1534 no-ops. The target's name is visible in the output of the following
1535 commands: "help target", "info target", "info files", "maint print
1538 * The "target native" command now connects to the native target. This
1539 can be used to launch native programs even when "set
1540 auto-connect-native-target" is set to off.
1542 * GDB now supports access to Intel MPX registers on GNU/Linux.
1544 * Support for Intel AVX-512 registers on GNU/Linux.
1545 Support displaying and modifying Intel AVX-512 registers
1546 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1548 * New remote packets
1550 qXfer:btrace:read's annex
1551 The qXfer:btrace:read packet supports a new annex 'delta' to read
1552 branch trace incrementally.
1556 ** Valid Python operations on gdb.Value objects representing
1557 structs/classes invoke the corresponding overloaded operators if
1559 ** New `Xmethods' feature in the Python API. Xmethods are
1560 additional methods or replacements for existing methods of a C++
1561 class. This feature is useful for those cases where a method
1562 defined in C++ source code could be inlined or optimized out by
1563 the compiler, making it unavailable to GDB.
1566 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1568 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1569 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1570 its alias "share", instead.
1572 * The commands "set remotebaud" and "show remotebaud" are no longer
1573 supported. Use "set serial baud" and "show serial baud" (respectively)
1578 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1579 target-async". The latter is left as a deprecated alias of the
1580 former for backward compatibility. If the target supports it,
1581 CLI background execution commands are now always possible by
1582 default, independently of whether the frontend stated a
1583 preference for asynchronous execution with "-gdb-set mi-async".
1584 Previously "-gdb-set target-async off" affected both MI execution
1585 commands and CLI execution commands.
1587 *** Changes in GDB 7.7
1589 * Improved support for process record-replay and reverse debugging on
1590 arm*-linux* targets. Support for thumb32 and syscall instruction
1591 recording has been added.
1593 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1595 * GDB now supports Fission DWP file format version 2.
1596 http://gcc.gnu.org/wiki/DebugFission
1598 * New convenience function "$_isvoid", to check whether an expression
1599 is void. A void expression is an expression where the type of the
1600 result is "void". For example, some convenience variables may be
1601 "void" when evaluated (e.g., "$_exitcode" before the execution of
1602 the program being debugged; or an undefined convenience variable).
1603 Another example, when calling a function whose return type is
1606 * The "maintenance print objfiles" command now takes an optional regexp.
1608 * The "catch syscall" command now works on arm*-linux* targets.
1610 * GDB now consistently shows "<not saved>" when printing values of
1611 registers the debug info indicates have not been saved in the frame
1612 and there's nowhere to retrieve them from
1613 (callee-saved/call-clobbered registers):
1618 (gdb) info registers rax
1621 Before, the former would print "<optimized out>", and the latter
1622 "*value not available*".
1624 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1629 ** Frame filters and frame decorators have been added.
1630 ** Temporary breakpoints are now supported.
1631 ** Line tables representation has been added.
1632 ** New attribute 'parent_type' for gdb.Field objects.
1633 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1634 ** New attribute 'name' for gdb.Type objects.
1638 Nios II ELF nios2*-*-elf
1639 Nios II GNU/Linux nios2*-*-linux
1640 Texas Instruments MSP430 msp430*-*-elf
1642 * Removed native configurations
1644 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1645 been removed. ELF variants of these configurations are kept supported.
1647 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1648 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1649 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1650 i[34567]86-*-openbsd3.[0-3]
1651 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1652 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1653 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1657 Like "catch throw", but catches a re-thrown exception.
1658 maint check-psymtabs
1659 Renamed from old "maint check-symtabs".
1661 Perform consistency checks on symtabs.
1662 maint expand-symtabs
1663 Expand symtabs matching an optional regexp.
1666 Display the details of GDB configure-time options.
1668 maint set|show per-command
1669 maint set|show per-command space
1670 maint set|show per-command time
1671 maint set|show per-command symtab
1672 Enable display of per-command gdb resource usage.
1674 remove-symbol-file FILENAME
1675 remove-symbol-file -a ADDRESS
1676 Remove a symbol file added via add-symbol-file. The file to remove
1677 can be identified by its filename or by an address that lies within
1678 the boundaries of this symbol file in memory.
1681 info exceptions REGEXP
1682 Display the list of Ada exceptions defined in the program being
1683 debugged. If provided, only the exceptions whose names match REGEXP
1688 set debug symfile off|on
1690 Control display of debugging info regarding reading symbol files and
1691 symbol tables within those files
1693 set print raw frame-arguments
1694 show print raw frame-arguments
1695 Set/show whether to print frame arguments in raw mode,
1696 disregarding any defined pretty-printers.
1698 set remote trace-status-packet
1699 show remote trace-status-packet
1700 Set/show the use of remote protocol qTStatus packet.
1704 Control display of debugging messages related to Nios II targets.
1708 Control whether target-assisted range stepping is enabled.
1710 set startup-with-shell
1711 show startup-with-shell
1712 Specifies whether Unix child processes are started via a shell or
1717 Use the target memory cache for accesses to the code segment. This
1718 improves performance of remote debugging (particularly disassembly).
1720 * You can now use a literal value 'unlimited' for options that
1721 interpret 0 or -1 as meaning "unlimited". E.g., "set
1722 trace-buffer-size unlimited" is now an alias for "set
1723 trace-buffer-size -1" and "set height unlimited" is now an alias for
1726 * The "set debug symtab-create" debugging option of GDB has been changed to
1727 accept a verbosity level. 0 means "off", 1 provides basic debugging
1728 output, and values of 2 or greater provides more verbose output.
1730 * New command-line options
1732 Display the details of GDB configure-time options.
1734 * The command 'tsave' can now support new option '-ctf' to save trace
1735 buffer in Common Trace Format.
1737 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1740 * GDB now implements the the C++ 'typeid' operator.
1742 * The new convenience variable $_exception holds the exception being
1743 thrown or caught at an exception-related catchpoint.
1745 * The exception-related catchpoints, like "catch throw", now accept a
1746 regular expression which can be used to filter exceptions by type.
1748 * The new convenience variable $_exitsignal is automatically set to
1749 the terminating signal number when the program being debugged dies
1750 due to an uncaught signal.
1754 ** All MI commands now accept an optional "--language" option.
1755 Support for this feature can be verified by using the "-list-features"
1756 command, which should contain "language-option".
1758 ** The new command -info-gdb-mi-command allows the user to determine
1759 whether a GDB/MI command is supported or not.
1761 ** The "^error" result record returned when trying to execute an undefined
1762 GDB/MI command now provides a variable named "code" whose content is the
1763 "undefined-command" error code. Support for this feature can be verified
1764 by using the "-list-features" command, which should contain
1765 "undefined-command-error-code".
1767 ** The -trace-save MI command can optionally save trace buffer in Common
1770 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1772 ** The command -data-list-register-values now accepts an optional
1773 "--skip-unavailable" option. When used, only the available registers
1776 ** The new command -trace-frame-collected dumps collected variables,
1777 computed expressions, tvars, memory and registers in a traceframe.
1779 ** The commands -stack-list-locals, -stack-list-arguments and
1780 -stack-list-variables now accept an option "--skip-unavailable".
1781 When used, only the available locals or arguments are displayed.
1783 ** The -exec-run command now accepts an optional "--start" option.
1784 When used, the command follows the same semantics as the "start"
1785 command, stopping the program's execution at the start of its
1786 main subprogram. Support for this feature can be verified using
1787 the "-list-features" command, which should contain
1788 "exec-run-start-option".
1790 ** The new commands -catch-assert and -catch-exceptions insert
1791 catchpoints stopping the program when Ada exceptions are raised.
1793 ** The new command -info-ada-exceptions provides the equivalent of
1794 the new "info exceptions" command.
1796 * New system-wide configuration scripts
1797 A GDB installation now provides scripts suitable for use as system-wide
1798 configuration scripts for the following systems:
1802 * GDB now supports target-assigned range stepping with remote targets.
1803 This improves the performance of stepping source lines by reducing
1804 the number of control packets from/to GDB. See "New remote packets"
1807 * GDB now understands the element 'tvar' in the XML traceframe info.
1808 It has the id of the collected trace state variables.
1810 * On S/390 targets that provide the transactional-execution feature,
1811 the program interruption transaction diagnostic block (TDB) is now
1812 represented as a number of additional "registers" in GDB.
1814 * New remote packets
1818 The vCont packet supports a new 'r' action, that tells the remote
1819 stub to step through an address range itself, without GDB
1820 involvemement at each single-step.
1822 qXfer:libraries-svr4:read's annex
1823 The previously unused annex of the qXfer:libraries-svr4:read packet
1824 is now used to support passing an argument list. The remote stub
1825 reports support for this argument list to GDB's qSupported query.
1826 The defined arguments are "start" and "prev", used to reduce work
1827 necessary for library list updating, resulting in significant
1830 * New features in the GDB remote stub, GDBserver
1832 ** GDBserver now supports target-assisted range stepping. Currently
1833 enabled on x86/x86_64 GNU/Linux targets.
1835 ** GDBserver now adds element 'tvar' in the XML in the reply to
1836 'qXfer:traceframe-info:read'. It has the id of the collected
1837 trace state variables.
1839 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1842 * New 'z' formatter for printing and examining memory, this displays the
1843 value as hexadecimal zero padded on the left to the size of the type.
1845 * GDB can now use Windows x64 unwinding data.
1847 * The "set remotebaud" command has been replaced by "set serial baud".
1848 Similarly, "show remotebaud" has been replaced by "show serial baud".
1849 The "set remotebaud" and "show remotebaud" commands are still available
1850 to provide backward compatibility with older versions of GDB.
1852 *** Changes in GDB 7.6
1854 * Target record has been renamed to record-full.
1855 Record/replay is now enabled with the "record full" command.
1856 This also affects settings that are associated with full record/replay
1857 that have been moved from "set/show record" to "set/show record full":
1859 set|show record full insn-number-max
1860 set|show record full stop-at-limit
1861 set|show record full memory-query
1863 * A new record target "record-btrace" has been added. The new target
1864 uses hardware support to record the control-flow of a process. It
1865 does not support replaying the execution, but it implements the
1866 below new commands for investigating the recorded execution log.
1867 This new recording method can be enabled using:
1871 The "record-btrace" target is only available on Intel Atom processors
1872 and requires a Linux kernel 2.6.32 or later.
1874 * Two new commands have been added for record/replay to give information
1875 about the recorded execution without having to replay the execution.
1876 The commands are only supported by "record btrace".
1878 record instruction-history prints the execution history at
1879 instruction granularity
1881 record function-call-history prints the execution history at
1882 function granularity
1884 * New native configurations
1886 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1887 FreeBSD/powerpc powerpc*-*-freebsd
1888 x86_64/Cygwin x86_64-*-cygwin*
1889 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1893 ARM AArch64 aarch64*-*-elf
1894 ARM AArch64 GNU/Linux aarch64*-*-linux
1895 Lynx 178 PowerPC powerpc-*-lynx*178
1896 x86_64/Cygwin x86_64-*-cygwin*
1897 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1899 * If the configured location of system.gdbinit file (as given by the
1900 --with-system-gdbinit option at configure time) is in the
1901 data-directory (as specified by --with-gdb-datadir at configure
1902 time) or in one of its subdirectories, then GDB will look for the
1903 system-wide init file in the directory specified by the
1904 --data-directory command-line option.
1906 * New command line options:
1908 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1909 other initialization files, unlike -nx which disables all of them.
1911 * Removed command line options
1913 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1916 * The 'ptype' and 'whatis' commands now accept an argument to control
1919 * 'info proc' now works on some core files.
1923 ** Vectors can be created with gdb.Type.vector.
1925 ** Python's atexit.register now works in GDB.
1927 ** Types can be pretty-printed via a Python API.
1929 ** Python 3 is now supported (in addition to Python 2.4 or later)
1931 ** New class gdb.Architecture exposes GDB's internal representation
1932 of architecture in the Python API.
1934 ** New method Frame.architecture returns the gdb.Architecture object
1935 corresponding to the frame's architecture.
1937 * New Python-based convenience functions:
1939 ** $_memeq(buf1, buf2, length)
1940 ** $_streq(str1, str2)
1942 ** $_regex(str, regex)
1944 * The 'cd' command now defaults to using '~' (the home directory) if not
1947 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1948 default for GCC since November 2000.
1950 * The command 'forward-search' can now be abbreviated as 'fo'.
1952 * The command 'info tracepoints' can now display 'installed on target'
1953 or 'not installed on target' for each non-pending location of tracepoint.
1955 * New configure options
1957 --enable-libmcheck/--disable-libmcheck
1958 By default, development versions are built with -lmcheck on hosts
1959 that support it, in order to help track memory corruption issues.
1960 Release versions, on the other hand, are built without -lmcheck
1961 by default. The --enable-libmcheck/--disable-libmcheck configure
1962 options allow the user to override that default.
1963 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1964 This configure option allows the user to build GDB with
1965 libbabeltrace using which GDB can read Common Trace Format data.
1967 * New commands (for set/show, see "New options" below)
1970 Catch signals. This is similar to "handle", but allows commands and
1971 conditions to be attached.
1974 List the BFDs known to GDB.
1976 python-interactive [command]
1978 Start a Python interactive prompt, or evaluate the optional command
1979 and print the result of expressions.
1982 "py" is a new alias for "python".
1984 enable type-printer [name]...
1985 disable type-printer [name]...
1986 Enable or disable type printers.
1990 ** For the Renesas Super-H architecture, the "regs" command has been removed
1991 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1996 set print type methods (on|off)
1997 show print type methods
1998 Control whether method declarations are displayed by "ptype".
1999 The default is to show them.
2001 set print type typedefs (on|off)
2002 show print type typedefs
2003 Control whether typedef definitions are displayed by "ptype".
2004 The default is to show them.
2006 set filename-display basename|relative|absolute
2007 show filename-display
2008 Control the way in which filenames is displayed.
2009 The default is "relative", which preserves previous behavior.
2011 set trace-buffer-size
2012 show trace-buffer-size
2013 Request target to change the size of trace buffer.
2015 set remote trace-buffer-size-packet auto|on|off
2016 show remote trace-buffer-size-packet
2017 Control the use of the remote protocol `QTBuffer:size' packet.
2021 Control display of debugging messages related to ARM AArch64.
2024 set debug coff-pe-read
2025 show debug coff-pe-read
2026 Control display of debugging messages related to reading of COFF/PE
2031 Control display of debugging messages related to Mach-O symbols
2034 set debug notification
2035 show debug notification
2036 Control display of debugging info for async remote notification.
2040 ** Command parameter changes are now notified using new async record
2041 "=cmd-param-changed".
2042 ** Trace frame changes caused by command "tfind" are now notified using
2043 new async record "=traceframe-changed".
2044 ** The creation, deletion and modification of trace state variables
2045 are now notified using new async records "=tsv-created",
2046 "=tsv-deleted" and "=tsv-modified".
2047 ** The start and stop of process record are now notified using new
2048 async record "=record-started" and "=record-stopped".
2049 ** Memory changes are now notified using new async record
2051 ** The data-disassemble command response will include a "fullname" field
2052 containing the absolute file name when source has been requested.
2053 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2054 command, to allow pattern filling of memory areas.
2055 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2056 library load/unload events.
2057 ** The response to breakpoint commands and breakpoint async records
2058 includes an "installed" field containing a boolean state about each
2059 non-pending tracepoint location is whether installed on target or not.
2060 ** Output of the "-trace-status" command includes a "trace-file" field
2061 containing the name of the trace file being examined. This field is
2062 optional, and only present when examining a trace file.
2063 ** The "fullname" field is now always present along with the "file" field,
2064 even if the file cannot be found by GDB.
2066 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2067 You must have the LZMA library available when configuring GDB for this
2068 feature to be enabled. For more information, see:
2069 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2071 * New remote packets
2074 Set the size of trace buffer. The remote stub reports support for this
2075 packet to gdb's qSupported query.
2078 Enable Branch Trace Store (BTS)-based branch tracing for the current
2079 thread. The remote stub reports support for this packet to gdb's
2083 Disable branch tracing for the current thread. The remote stub reports
2084 support for this packet to gdb's qSupported query.
2087 Read the traced branches for the current thread. The remote stub
2088 reports support for this packet to gdb's qSupported query.
2090 *** Changes in GDB 7.5
2092 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2093 for more x32 ABI info.
2095 * GDB now supports access to MIPS DSP registers on Linux targets.
2097 * GDB now supports debugging microMIPS binaries.
2099 * The "info os" command on GNU/Linux can now display information on
2100 several new classes of objects managed by the operating system:
2101 "info os procgroups" lists process groups
2102 "info os files" lists file descriptors
2103 "info os sockets" lists internet-domain sockets
2104 "info os shm" lists shared-memory regions
2105 "info os semaphores" lists semaphores
2106 "info os msg" lists message queues
2107 "info os modules" lists loaded kernel modules
2109 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2110 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2111 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2112 options and inspect the probe arguments using the new $_probe_arg family
2113 of convenience variables. You can obtain more information about SystemTap
2114 in <http://sourceware.org/systemtap/>.
2116 * GDB now supports reversible debugging on ARM, it allows you to
2117 debug basic ARM and THUMB instructions, and provides
2118 record/replay support.
2120 * The option "symbol-reloading" has been deleted as it is no longer used.
2124 ** GDB commands implemented in Python can now be put in command class
2127 ** The "maint set python print-stack on|off" is now deleted.
2129 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2130 apply "flag enum"-style pretty-printing to any enum.
2132 ** gdb.lookup_symbol can now work when there is no current frame.
2134 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2135 the source at which the symbol was defined.
2137 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2138 method 'value'. The former indicates whether the symbol needs a
2139 frame in order to compute its value, and the latter computes the
2142 ** A new method 'referenced_value' on gdb.Value objects which can
2143 dereference pointer as well as C++ reference values.
2145 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2146 which return the global and static blocks (as gdb.Block objects),
2147 of the underlying symbol table, respectively.
2149 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2150 object associated with a PC value.
2152 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2153 of the address range occupied by code for the current source line.
2155 * Go language support.
2156 GDB now supports debugging programs written in the Go programming
2159 * GDBserver now supports stdio connections.
2160 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2162 * The binary "gdbtui" can no longer be built or installed.
2163 Use "gdb -tui" instead.
2165 * GDB will now print "flag" enums specially. A flag enum is one where
2166 all the enumerator values have no bits in common when pairwise
2167 "and"ed. When printing a value whose type is a flag enum, GDB will
2168 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2169 (gdb) print (enum E) 3
2172 * The filename part of a linespec will now match trailing components
2173 of a source file name. For example, "break gcc/expr.c:1000" will
2174 now set a breakpoint in build/gcc/expr.c, but not
2175 build/libcpp/expr.c.
2177 * The "info proc" and "generate-core-file" commands will now also
2178 work on remote targets connected to GDBserver on Linux.
2180 * The command "info catch" has been removed. It has been disabled
2181 since December 2007.
2183 * The "catch exception" and "catch assert" commands now accept
2184 a condition at the end of the command, much like the "break"
2185 command does. For instance:
2187 (gdb) catch exception Constraint_Error if Barrier = True
2189 Previously, it was possible to add a condition to such catchpoints,
2190 but it had to be done as a second step, after the catchpoint had been
2191 created, using the "condition" command.
2193 * The "info static-tracepoint-marker" command will now also work on
2194 native Linux targets with in-process agent.
2196 * GDB can now set breakpoints on inlined functions.
2198 * The .gdb_index section has been updated to include symbols for
2199 inlined functions. GDB will ignore older .gdb_index sections by
2200 default, which could cause symbol files to be loaded more slowly
2201 until their .gdb_index sections can be recreated. The new command
2202 "set use-deprecated-index-sections on" will cause GDB to use any older
2203 .gdb_index sections it finds. This will restore performance, but the
2204 ability to set breakpoints on inlined functions will be lost in symbol
2205 files with older .gdb_index sections.
2207 The .gdb_index section has also been updated to record more information
2208 about each symbol. This speeds up the "info variables", "info functions"
2209 and "info types" commands when used with programs having the .gdb_index
2210 section, as well as speeding up debugging with shared libraries using
2211 the .gdb_index section.
2213 * Ada support for GDB/MI Variable Objects has been added.
2215 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2220 ** New command -info-os is the MI equivalent of "info os".
2222 ** Output logs ("set logging" and related) now include MI output.
2226 ** "set use-deprecated-index-sections on|off"
2227 "show use-deprecated-index-sections on|off"
2228 Controls the use of deprecated .gdb_index sections.
2230 ** "catch load" and "catch unload" can be used to stop when a shared
2231 library is loaded or unloaded, respectively.
2233 ** "enable count" can be used to auto-disable a breakpoint after
2236 ** "info vtbl" can be used to show the virtual method tables for
2237 C++ and Java objects.
2239 ** "explore" and its sub commands "explore value" and "explore type"
2240 can be used to recursively explore values and types of
2241 expressions. These commands are available only if GDB is
2242 configured with '--with-python'.
2244 ** "info auto-load" shows status of all kinds of auto-loaded files,
2245 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2246 sequences of commands files, "info auto-load python-scripts"
2247 shows status of auto-loading Python script files,
2248 "info auto-load local-gdbinit" shows status of loading init file
2249 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2250 status of inferior specific thread debugging shared library loading.
2252 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2253 and "show auto-load-scripts" commands have been deprecated, use their
2254 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2255 and "show auto-load python-scripts" counterparts instead.
2257 ** "dprintf location,format,args..." creates a dynamic printf, which
2258 is basically a breakpoint that does a printf and immediately
2259 resumes your program's execution, so it is like a printf that you
2260 can insert dynamically at runtime instead of at compiletime.
2262 ** "set print symbol"
2264 Controls whether GDB attempts to display the symbol, if any,
2265 corresponding to addresses it prints. This defaults to "on", but
2266 you can set it to "off" to restore GDB's previous behavior.
2268 * Deprecated commands
2270 ** For the Renesas Super-H architecture, the "regs" command has been
2271 deprecated, and "info all-registers" should be used instead.
2275 Renesas RL78 rl78-*-elf
2276 HP OpenVMS ia64 ia64-hp-openvms*
2278 * GDBserver supports evaluation of breakpoint conditions. When
2279 support is advertised by GDBserver, GDB may be told to send the
2280 breakpoint conditions in bytecode form to GDBserver. GDBserver
2281 will only report the breakpoint trigger to GDB when its condition
2286 set mips compression
2287 show mips compression
2288 Select the compressed ISA encoding used in functions that have no symbol
2289 information available. The encoding can be set to either of:
2292 and is updated automatically from ELF file flags if available.
2294 set breakpoint condition-evaluation
2295 show breakpoint condition-evaluation
2296 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2297 GDBserver ("target"). Default option "auto" chooses the most efficient
2299 This option can improve debugger efficiency depending on the speed of the
2303 Disable auto-loading globally.
2306 Show auto-loading setting of all kinds of auto-loaded files.
2308 set auto-load gdb-scripts on|off
2309 show auto-load gdb-scripts
2310 Control auto-loading of GDB canned sequences of commands files.
2312 set auto-load python-scripts on|off
2313 show auto-load python-scripts
2314 Control auto-loading of Python script files.
2316 set auto-load local-gdbinit on|off
2317 show auto-load local-gdbinit
2318 Control loading of init file (.gdbinit) from current directory.
2320 set auto-load libthread-db on|off
2321 show auto-load libthread-db
2322 Control auto-loading of inferior specific thread debugging shared library.
2324 set auto-load scripts-directory <dir1>[:<dir2>...]
2325 show auto-load scripts-directory
2326 Set a list of directories from which to load auto-loaded scripts.
2327 Automatically loaded Python scripts and GDB scripts are located in one
2328 of the directories listed by this option.
2329 The delimiter (':' above) may differ according to the host platform.
2331 set auto-load safe-path <dir1>[:<dir2>...]
2332 show auto-load safe-path
2333 Set a list of directories from which it is safe to auto-load files.
2334 The delimiter (':' above) may differ according to the host platform.
2336 set debug auto-load on|off
2337 show debug auto-load
2338 Control display of debugging info for auto-loading the files above.
2340 set dprintf-style gdb|call|agent
2342 Control the way in which a dynamic printf is performed; "gdb"
2343 requests a GDB printf command, while "call" causes dprintf to call a
2344 function in the inferior. "agent" requests that the target agent
2345 (such as GDBserver) do the printing.
2347 set dprintf-function <expr>
2348 show dprintf-function
2349 set dprintf-channel <expr>
2350 show dprintf-channel
2351 Set the function and optional first argument to the call when using
2352 the "call" style of dynamic printf.
2354 set disconnected-dprintf on|off
2355 show disconnected-dprintf
2356 Control whether agent-style dynamic printfs continue to be in effect
2357 after GDB disconnects.
2359 * New configure options
2361 --with-auto-load-dir
2362 Configure default value for the 'set auto-load scripts-directory'
2363 setting above. It defaults to '$debugdir:$datadir/auto-load',
2364 $debugdir representing global debugging info directories (available
2365 via 'show debug-file-directory') and $datadir representing GDB's data
2366 directory (available via 'show data-directory').
2368 --with-auto-load-safe-path
2369 Configure default value for the 'set auto-load safe-path' setting
2370 above. It defaults to the --with-auto-load-dir setting.
2372 --without-auto-load-safe-path
2373 Set 'set auto-load safe-path' to '/', effectively disabling this
2376 * New remote packets
2378 z0/z1 conditional breakpoints extension
2380 The z0/z1 breakpoint insertion packets have been extended to carry
2381 a list of conditional expressions over to the remote stub depending on the
2382 condition evaluation mode. The use of this extension can be controlled
2383 via the "set remote conditional-breakpoints-packet" command.
2387 Specify the signals which the remote stub may pass to the debugged
2388 program without GDB involvement.
2390 * New command line options
2392 --init-command=FILE, -ix Like --command, -x but execute it
2393 before loading inferior.
2394 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2395 execute it before loading inferior.
2397 *** Changes in GDB 7.4
2399 * GDB now handles ambiguous linespecs more consistently; the existing
2400 FILE:LINE support has been expanded to other types of linespecs. A
2401 breakpoint will now be set on all matching locations in all
2402 inferiors, and locations will be added or removed according to
2405 * GDB now allows you to skip uninteresting functions and files when
2406 stepping with the "skip function" and "skip file" commands.
2408 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2409 and "show remote hardware-watchpoint-length-limit". These allows to
2410 set or show the maximum length limit (in bytes) of a remote
2411 target hardware watchpoint.
2413 This allows e.g. to use "unlimited" hardware watchpoints with the
2414 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2415 watchpoints are slower than real hardware watchpoints but are
2416 significantly faster than gdb software watchpoints.
2420 ** The register_pretty_printer function in module gdb.printing now takes
2421 an optional `replace' argument. If True, the new printer replaces any
2424 ** The "maint set python print-stack on|off" command has been
2425 deprecated and will be deleted in GDB 7.5.
2426 A new command: "set python print-stack none|full|message" has
2427 replaced it. Additionally, the default for "print-stack" is
2428 now "message", which just prints the error message without
2431 ** A prompt substitution hook (prompt_hook) is now available to the
2434 ** A new Python module, gdb.prompt has been added to the GDB Python
2435 modules library. This module provides functionality for
2436 escape sequences in prompts (used by set/show
2437 extended-prompt). These escape sequences are replaced by their
2438 corresponding value.
2440 ** Python commands and convenience-functions located in
2441 'data-directory'/python/gdb/command and
2442 'data-directory'/python/gdb/function are now automatically loaded
2445 ** Blocks now provide four new attributes. global_block and
2446 static_block will return the global and static blocks
2447 respectively. is_static and is_global are boolean attributes
2448 that indicate if the block is one of those two types.
2450 ** Symbols now provide the "type" attribute, the type of the symbol.
2452 ** The "gdb.breakpoint" function has been deprecated in favor of
2455 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2456 of a function. This class is based on the "finish" command
2457 available in the CLI.
2459 ** Type objects for struct and union types now allow access to
2460 the fields using standard Python dictionary (mapping) methods.
2461 For example, "some_type['myfield']" now works, as does
2462 "some_type.items()".
2464 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2467 ** A new function, "deep_items" has been added to the gdb.types
2468 module in the GDB Python modules library. This function returns
2469 an iterator over the fields of a struct or union type. Unlike
2470 the standard Python "iteritems" method, it will recursively traverse
2471 any anonymous fields.
2475 ** "*stopped" events can report several new "reason"s, such as
2478 ** Breakpoint changes are now notified using new async records, like
2479 "=breakpoint-modified".
2481 ** New command -ada-task-info.
2483 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2484 $sdir specifies the default system locations of shared libraries.
2485 $pdir specifies the directory where the libpthread used by the application
2488 GDB no longer looks in $sdir and $pdir after it has searched the directories
2489 mentioned in libthread-db-search-path. If you want to search those
2490 directories, they must be specified in libthread-db-search-path.
2491 The default value of libthread-db-search-path on GNU/Linux and Solaris
2492 systems is now "$sdir:$pdir".
2494 $pdir is not supported by gdbserver, it is currently ignored.
2495 $sdir is supported by gdbserver.
2497 * New configure option --with-iconv-bin.
2498 When using the internationalization support like the one in the GNU C
2499 library, GDB will invoke the "iconv" program to get a list of supported
2500 character sets. If this program lives in a non-standard location, one can
2501 use this option to specify where to find it.
2503 * When natively debugging programs on PowerPC BookE processors running
2504 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2505 watchpoints, which specify a mask in addition to an address to watch.
2506 The mask specifies that some bits of an address (the bits which are
2507 reset in the mask) should be ignored when matching the address accessed
2508 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2509 section in the user manual for more details.
2511 * The new option --once causes GDBserver to stop listening for connections once
2512 the first connection is made. The listening port used by GDBserver will
2513 become available after that.
2515 * New commands "info macros" and "alias" have been added.
2517 * New function parameters suffix @entry specifies value of function parameter
2518 at the time the function got called. Entry values are available only since
2524 "!" is now an alias of the "shell" command.
2525 Note that no space is needed between "!" and SHELL COMMAND.
2529 watch EXPRESSION mask MASK_VALUE
2530 The watch command now supports the mask argument which allows creation
2531 of masked watchpoints, if the current architecture supports this feature.
2533 info auto-load-scripts [REGEXP]
2534 This command was formerly named "maintenance print section-scripts".
2535 It is now generally useful and is no longer a maintenance-only command.
2537 info macro [-all] [--] MACRO
2538 The info macro command has new options `-all' and `--'. The first for
2539 printing all definitions of a macro. The second for explicitly specifying
2540 the end of arguments and the beginning of the macro name in case the macro
2541 name starts with a hyphen.
2543 collect[/s] EXPRESSIONS
2544 The tracepoint collect command now takes an optional modifier "/s"
2545 that directs it to dereference pointer-to-character types and
2546 collect the bytes of memory up to a zero byte. The behavior is
2547 similar to what you see when you use the regular print command on a
2548 string. An optional integer following the "/s" sets a bound on the
2549 number of bytes that will be collected.
2552 The trace start command now interprets any supplied arguments as a
2553 note to be recorded with the trace run, with an effect similar to
2554 setting the variable trace-notes.
2557 The trace stop command now interprets any arguments as a note to be
2558 mentioned along with the tstatus report that the trace was stopped
2559 with a command. The effect is similar to setting the variable
2562 * Tracepoints can now be enabled and disabled at any time after a trace
2563 experiment has been started using the standard "enable" and "disable"
2564 commands. It is now possible to start a trace experiment with no enabled
2565 tracepoints; GDB will display a warning, but will allow the experiment to
2566 begin, assuming that tracepoints will be enabled as needed while the trace
2569 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2570 locations with 4-byte instructions, when they were previously
2571 limited to locations with instructions of 5 bytes or longer.
2575 set debug dwarf2-read
2576 show debug dwarf2-read
2577 Turns on or off display of debugging messages related to reading
2578 DWARF debug info. The default is off.
2580 set debug symtab-create
2581 show debug symtab-create
2582 Turns on or off display of debugging messages related to symbol table
2583 creation. The default is off.
2586 show extended-prompt
2587 Set the GDB prompt, and allow escape sequences to be inserted to
2588 display miscellaneous information (see 'help set extended-prompt'
2589 for the list of sequences). This prompt (and any information
2590 accessed through the escape sequences) is updated every time the
2591 prompt is displayed.
2593 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2594 show print entry-values
2595 Set printing of frame argument values at function entry. In some cases
2596 GDB can determine the value of function argument which was passed by the
2597 function caller, even if the value was modified inside the called function.
2599 set debug entry-values
2600 show debug entry-values
2601 Control display of debugging info for determining frame argument values at
2602 function entry and virtual tail call frames.
2604 set basenames-may-differ
2605 show basenames-may-differ
2606 Set whether a source file may have multiple base names.
2607 (A "base name" is the name of a file with the directory part removed.
2608 Example: The base name of "/home/user/hello.c" is "hello.c".)
2609 If set, GDB will canonicalize file names (e.g., expand symlinks)
2610 before comparing them. Canonicalization is an expensive operation,
2611 but it allows the same file be known by more than one base name.
2612 If not set (the default), all source files are assumed to have just
2613 one base name, and gdb will do file name comparisons more efficiently.
2619 Set a user name and notes for the current and any future trace runs.
2620 This is useful for long-running and/or disconnected traces, to
2621 inform others (or yourself) as to who is running the trace, supply
2622 contact information, or otherwise explain what is going on.
2624 set trace-stop-notes
2625 show trace-stop-notes
2626 Set a note attached to the trace run, that is displayed when the
2627 trace has been stopped by a tstop command. This is useful for
2628 instance as an explanation, if you are stopping a trace run that was
2629 started by someone else.
2631 * New remote packets
2635 Dynamically enable a tracepoint in a started trace experiment.
2639 Dynamically disable a tracepoint in a started trace experiment.
2643 Set the user and notes of the trace run.
2647 Query the current status of a tracepoint.
2651 Query the minimum length of instruction at which a fast tracepoint may
2654 * Dcache size (number of lines) and line-size are now runtime-configurable
2655 via "set dcache line" and "set dcache line-size" commands.
2659 Texas Instruments TMS320C6x tic6x-*-*
2663 Renesas RL78 rl78-*-elf
2665 *** Changes in GDB 7.3.1
2667 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2669 *** Changes in GDB 7.3
2671 * GDB has a new command: "thread find [REGEXP]".
2672 It finds the thread id whose name, target id, or thread extra info
2673 matches the given regular expression.
2675 * The "catch syscall" command now works on mips*-linux* targets.
2677 * The -data-disassemble MI command now supports modes 2 and 3 for
2678 dumping the instruction opcodes.
2680 * New command line options
2682 -data-directory DIR Specify DIR as the "data-directory".
2683 This is mostly for testing purposes.
2685 * The "maint set python auto-load on|off" command has been renamed to
2686 "set auto-load-scripts on|off".
2688 * GDB has a new command: "set directories".
2689 It is like the "dir" command except that it replaces the
2690 source path list instead of augmenting it.
2692 * GDB now understands thread names.
2694 On GNU/Linux, "info threads" will display the thread name as set by
2695 prctl or pthread_setname_np.
2697 There is also a new command, "thread name", which can be used to
2698 assign a name internally for GDB to display.
2701 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2702 has been integrated into GDB.
2706 ** The function gdb.Write now accepts an optional keyword 'stream'.
2707 This keyword, when provided, will direct the output to either
2708 stdout, stderr, or GDB's logging output.
2710 ** Parameters can now be be sub-classed in Python, and in particular
2711 you may implement the get_set_doc and get_show_doc functions.
2712 This improves how Parameter set/show documentation is processed
2713 and allows for more dynamic content.
2715 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2716 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2717 have an is_valid method.
2719 ** Breakpoints can now be sub-classed in Python, and in particular
2720 you may implement a 'stop' function that is executed each time
2721 the inferior reaches that breakpoint.
2723 ** New function gdb.lookup_global_symbol looks up a global symbol.
2725 ** GDB values in Python are now callable if the value represents a
2726 function. For example, if 'some_value' represents a function that
2727 takes two integer parameters and returns a value, you can call
2728 that function like so:
2730 result = some_value (10,20)
2732 ** Module gdb.types has been added.
2733 It contains a collection of utilities for working with gdb.Types objects:
2734 get_basic_type, has_field, make_enum_dict.
2736 ** Module gdb.printing has been added.
2737 It contains utilities for writing and registering pretty-printers.
2738 New classes: PrettyPrinter, SubPrettyPrinter,
2739 RegexpCollectionPrettyPrinter.
2740 New function: register_pretty_printer.
2742 ** New commands "info pretty-printers", "enable pretty-printer" and
2743 "disable pretty-printer" have been added.
2745 ** gdb.parameter("directories") is now available.
2747 ** New function gdb.newest_frame returns the newest frame in the
2750 ** The gdb.InferiorThread class has a new "name" attribute. This
2751 holds the thread's name.
2753 ** Python Support for Inferior events.
2754 Python scripts can add observers to be notified of events
2755 occurring in the process being debugged.
2756 The following events are currently supported:
2757 - gdb.events.cont Continue event.
2758 - gdb.events.exited Inferior exited event.
2759 - gdb.events.stop Signal received, and Breakpoint hit events.
2763 ** GDB now puts template parameters in scope when debugging in an
2764 instantiation. For example, if you have:
2766 template<int X> int func (void) { return X; }
2768 then if you step into func<5>, "print X" will show "5". This
2769 feature requires proper debuginfo support from the compiler; it
2770 was added to GCC 4.5.
2772 ** The motion commands "next", "finish", "until", and "advance" now
2773 work better when exceptions are thrown. In particular, GDB will
2774 no longer lose control of the inferior; instead, the GDB will
2775 stop the inferior at the point at which the exception is caught.
2776 This functionality requires a change in the exception handling
2777 code that was introduced in GCC 4.5.
2779 * GDB now follows GCC's rules on accessing volatile objects when
2780 reading or writing target state during expression evaluation.
2781 One notable difference to prior behavior is that "print x = 0"
2782 no longer generates a read of x; the value of the assignment is
2783 now always taken directly from the value being assigned.
2785 * GDB now has some support for using labels in the program's source in
2786 linespecs. For instance, you can use "advance label" to continue
2787 execution to a label.
2789 * GDB now has support for reading and writing a new .gdb_index
2790 section. This section holds a fast index of DWARF debugging
2791 information and can be used to greatly speed up GDB startup and
2792 operation. See the documentation for `save gdb-index' for details.
2794 * The "watch" command now accepts an optional "-location" argument.
2795 When used, this causes GDB to watch the memory referred to by the
2796 expression. Such a watchpoint is never deleted due to it going out
2799 * GDB now supports thread debugging of core dumps on GNU/Linux.
2801 GDB now activates thread debugging using the libthread_db library
2802 when debugging GNU/Linux core dumps, similarly to when debugging
2803 live processes. As a result, when debugging a core dump file, GDB
2804 is now able to display pthread_t ids of threads. For example, "info
2805 threads" shows the same output as when debugging the process when it
2806 was live. In earlier releases, you'd see something like this:
2809 * 1 LWP 6780 main () at main.c:10
2811 While now you see this:
2814 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2816 It is also now possible to inspect TLS variables when debugging core
2819 When debugging a core dump generated on a machine other than the one
2820 used to run GDB, you may need to point GDB at the correct
2821 libthread_db library with the "set libthread-db-search-path"
2822 command. See the user manual for more details on this command.
2824 * When natively debugging programs on PowerPC BookE processors running
2825 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2826 which stop execution of the inferior whenever it executes an instruction
2827 at any address within the specified range. See the "PowerPC Embedded"
2828 section in the user manual for more details.
2830 * New features in the GDB remote stub, GDBserver
2832 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2833 and i686 LynxOS (version 5.x).
2835 ** GDBserver is now supported on Blackfin Linux.
2837 * New native configurations
2839 ia64 HP-UX ia64-*-hpux*
2843 Analog Devices, Inc. Blackfin Processor bfin-*
2845 * Ada task switching is now supported on sparc-elf targets when
2846 debugging a program using the Ravenscar Profile. For more information,
2847 see the "Tasking Support when using the Ravenscar Profile" section
2848 in the GDB user manual.
2850 * Guile support was removed.
2852 * New features in the GNU simulator
2854 ** The --map-info flag lists all known core mappings.
2856 ** CFI flashes may be simulated via the "cfi" device.
2858 *** Changes in GDB 7.2
2860 * Shared library support for remote targets by default
2862 When GDB is configured for a generic, non-OS specific target, like
2863 for example, --target=arm-eabi or one of the many *-*-elf targets,
2864 GDB now queries remote stubs for loaded shared libraries using the
2865 `qXfer:libraries:read' packet. Previously, shared library support
2866 was always disabled for such configurations.
2870 ** Argument Dependent Lookup (ADL)
2872 In C++ ADL lookup directs function search to the namespaces of its
2873 arguments even if the namespace has not been imported.
2883 Here the compiler will search for `foo' in the namespace of 'b'
2884 and find A::foo. GDB now supports this. This construct is commonly
2885 used in the Standard Template Library for operators.
2887 ** Improved User Defined Operator Support
2889 In addition to member operators, GDB now supports lookup of operators
2890 defined in a namespace and imported with a `using' directive, operators
2891 defined in the global scope, operators imported implicitly from an
2892 anonymous namespace, and the ADL operators mentioned in the previous
2894 GDB now also supports proper overload resolution for all the previously
2895 mentioned flavors of operators.
2897 ** static const class members
2899 Printing of static const class members that are initialized in the
2900 class definition has been fixed.
2902 * Windows Thread Information Block access.
2904 On Windows targets, GDB now supports displaying the Windows Thread
2905 Information Block (TIB) structure. This structure is visible either
2906 by using the new command `info w32 thread-information-block' or, by
2907 dereferencing the new convenience variable named `$_tlb', a
2908 thread-specific pointer to the TIB. This feature is also supported
2909 when remote debugging using GDBserver.
2911 * Static tracepoints
2913 Static tracepoints are calls in the user program into a tracing
2914 library. One such library is a port of the LTTng kernel tracer to
2915 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2916 When debugging with GDBserver, GDB now supports combining the GDB
2917 tracepoint machinery with such libraries. For example: the user can
2918 use GDB to probe a static tracepoint marker (a call from the user
2919 program into the tracing library) with the new "strace" command (see
2920 "New commands" below). This creates a "static tracepoint" in the
2921 breakpoint list, that can be manipulated with the same feature set
2922 as fast and regular tracepoints. E.g., collect registers, local and
2923 global variables, collect trace state variables, and define
2924 tracepoint conditions. In addition, the user can collect extra
2925 static tracepoint marker specific data, by collecting the new
2926 $_sdata internal variable. When analyzing the trace buffer, you can
2927 inspect $_sdata like any other variable available to GDB. For more
2928 information, see the "Tracepoints" chapter in GDB user manual. New
2929 remote packets have been defined to support static tracepoints, see
2930 the "New remote packets" section below.
2932 * Better reconstruction of tracepoints after disconnected tracing
2934 GDB will attempt to download the original source form of tracepoint
2935 definitions when starting a trace run, and then will upload these
2936 upon reconnection to the target, resulting in a more accurate
2937 reconstruction of the tracepoints that are in use on the target.
2941 You can now exercise direct control over the ways that GDB can
2942 affect your program. For instance, you can disallow the setting of
2943 breakpoints, so that the program can run continuously (assuming
2944 non-stop mode). In addition, the "observer" variable is available
2945 to switch all of the different controls; in observer mode, GDB
2946 cannot affect the target's behavior at all, which is useful for
2947 tasks like diagnosing live systems in the field.
2949 * The new convenience variable $_thread holds the number of the
2952 * New remote packets
2956 Return the address of the Windows Thread Information Block of a given thread.
2960 In response to several of the tracepoint packets, the target may now
2961 also respond with a number of intermediate `qRelocInsn' request
2962 packets before the final result packet, to have GDB handle
2963 relocating an instruction to execute at a different address. This
2964 is particularly useful for stubs that support fast tracepoints. GDB
2965 reports support for this feature in the qSupported packet.
2969 List static tracepoint markers in the target program.
2973 List static tracepoint markers at a given address in the target
2976 qXfer:statictrace:read
2978 Read the static trace data collected (by a `collect $_sdata'
2979 tracepoint action). The remote stub reports support for this packet
2980 to gdb's qSupported query.
2984 Send the current settings of GDB's permission flags.
2988 Send part of the source (textual) form of a tracepoint definition,
2989 which includes location, conditional, and action list.
2991 * The source command now accepts a -s option to force searching for the
2992 script in the source search path even if the script name specifies
2995 * New features in the GDB remote stub, GDBserver
2997 - GDBserver now support tracepoints (including fast tracepoints, and
2998 static tracepoints). The feature is currently supported by the
2999 i386-linux and amd64-linux builds. See the "Tracepoints support
3000 in gdbserver" section in the manual for more information.
3002 GDBserver JIT compiles the tracepoint's conditional agent
3003 expression bytecode into native code whenever possible for low
3004 overhead dynamic tracepoints conditionals. For such tracepoints,
3005 an expression that examines program state is evaluated when the
3006 tracepoint is reached, in order to determine whether to capture
3007 trace data. If the condition is simple and false, processing the
3008 tracepoint finishes very quickly and no data is gathered.
3010 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3011 for static tracepoints support.
3013 - GDBserver now supports x86_64 Windows 64-bit debugging.
3015 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3016 it understands register description.
3018 * The --batch flag now disables pagination and queries.
3020 * X86 general purpose registers
3022 GDB now supports reading/writing byte, word and double-word x86
3023 general purpose registers directly. This means you can use, say,
3024 $ah or $ax to refer, respectively, to the byte register AH and
3025 16-bit word register AX that are actually portions of the 32-bit
3026 register EAX or 64-bit register RAX.
3028 * The `commands' command now accepts a range of breakpoints to modify.
3029 A plain `commands' following a command that creates multiple
3030 breakpoints affects all the breakpoints set by that command. This
3031 applies to breakpoints set by `rbreak', and also applies when a
3032 single `break' command creates multiple breakpoints (e.g.,
3033 breakpoints on overloaded c++ functions).
3035 * The `rbreak' command now accepts a filename specification as part of
3036 its argument, limiting the functions selected by the regex to those
3037 in the specified file.
3039 * Support for remote debugging Windows and SymbianOS shared libraries
3040 from Unix hosts has been improved. Non Windows GDB builds now can
3041 understand target reported file names that follow MS-DOS based file
3042 system semantics, such as file names that include drive letters and
3043 use the backslash character as directory separator. This makes it
3044 possible to transparently use the "set sysroot" and "set
3045 solib-search-path" on Unix hosts to point as host copies of the
3046 target's shared libraries. See the new command "set
3047 target-file-system-kind" described below, and the "Commands to
3048 specify files" section in the user manual for more information.
3052 eval template, expressions...
3053 Convert the values of one or more expressions under the control
3054 of the string template to a command line, and call it.
3056 set target-file-system-kind unix|dos-based|auto
3057 show target-file-system-kind
3058 Set or show the assumed file system kind for target reported file
3061 save breakpoints <filename>
3062 Save all current breakpoint definitions to a file suitable for use
3063 in a later debugging session. To read the saved breakpoint
3064 definitions, use the `source' command.
3066 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3069 info static-tracepoint-markers
3070 Display information about static tracepoint markers in the target.
3072 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3073 Define a static tracepoint by probing a marker at the given
3074 function, line, address, or marker ID.
3078 Enable and disable observer mode.
3080 set may-write-registers on|off
3081 set may-write-memory on|off
3082 set may-insert-breakpoints on|off
3083 set may-insert-tracepoints on|off
3084 set may-insert-fast-tracepoints on|off
3085 set may-interrupt on|off
3086 Set individual permissions for GDB effects on the target. Note that
3087 some of these settings can have undesirable or surprising
3088 consequences, particularly when changed in the middle of a session.
3089 For instance, disabling the writing of memory can prevent
3090 breakpoints from being inserted, cause single-stepping to fail, or
3091 even crash your program, if you disable after breakpoints have been
3092 inserted. However, GDB should not crash.
3094 set record memory-query on|off
3095 show record memory-query
3096 Control whether to stop the inferior if memory changes caused
3097 by an instruction cannot be recorded.
3102 The disassemble command now supports "start,+length" form of two arguments.
3106 ** GDB now provides a new directory location, called the python directory,
3107 where Python scripts written for GDB can be installed. The location
3108 of that directory is <data-directory>/python, where <data-directory>
3109 is the GDB data directory. For more details, see section `Scripting
3110 GDB using Python' in the manual.
3112 ** The GDB Python API now has access to breakpoints, symbols, symbol
3113 tables, program spaces, inferiors, threads and frame's code blocks.
3114 Additionally, GDB Parameters can now be created from the API, and
3115 manipulated via set/show in the CLI.
3117 ** New functions gdb.target_charset, gdb.target_wide_charset,
3118 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3120 ** New exception gdb.GdbError.
3122 ** Pretty-printers are now also looked up in the current program space.
3124 ** Pretty-printers can now be individually enabled and disabled.
3126 ** GDB now looks for names of Python scripts to auto-load in a
3127 special section named `.debug_gdb_scripts', in addition to looking
3128 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3130 * Tracepoint actions were unified with breakpoint commands. In particular,
3131 there are no longer differences in "info break" output for breakpoints and
3132 tracepoints and the "commands" command can be used for both tracepoints and
3133 regular breakpoints.
3137 ARM Symbian arm*-*-symbianelf*
3139 * D language support.
3140 GDB now supports debugging programs written in the D programming
3143 * GDB now supports the extended ptrace interface for PowerPC which is
3144 available since Linux kernel version 2.6.34. This automatically enables
3145 any hardware breakpoints and additional hardware watchpoints available in
3146 the processor. The old ptrace interface exposes just one hardware
3147 watchpoint and no hardware breakpoints.
3149 * GDB is now able to use the Data Value Compare (DVC) register available on
3150 embedded PowerPC processors to implement in hardware simple watchpoint
3151 conditions of the form:
3153 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3155 This works in native GDB running on Linux kernels with the extended ptrace
3156 interface mentioned above.
3158 *** Changes in GDB 7.1
3162 ** Namespace Support
3164 GDB now supports importing of namespaces in C++. This enables the
3165 user to inspect variables from imported namespaces. Support for
3166 namepace aliasing has also been added. So, if a namespace is
3167 aliased in the current scope (e.g. namepace C=A; ) the user can
3168 print variables using the alias (e.g. (gdb) print C::x).
3172 All known bugs relating to the printing of virtual base class were
3173 fixed. It is now possible to call overloaded static methods using a
3178 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3179 and reinterpret_cast<> are now handled by the C++ expression parser.
3183 Xilinx MicroBlaze microblaze-*-*
3188 Xilinx MicroBlaze microblaze
3191 * Multi-program debugging.
3193 GDB now has support for multi-program (a.k.a. multi-executable or
3194 multi-exec) debugging. This allows for debugging multiple inferiors
3195 simultaneously each running a different program under the same GDB
3196 session. See "Debugging Multiple Inferiors and Programs" in the
3197 manual for more information. This implied some user visible changes
3198 in the multi-inferior support. For example, "info inferiors" now
3199 lists inferiors that are not running yet or that have exited
3200 already. See also "New commands" and "New options" below.
3202 * New tracing features
3204 GDB's tracepoint facility now includes several new features:
3206 ** Trace state variables
3208 GDB tracepoints now include support for trace state variables, which
3209 are variables managed by the target agent during a tracing
3210 experiment. They are useful for tracepoints that trigger each
3211 other, so for instance one tracepoint can count hits in a variable,
3212 and then a second tracepoint has a condition that is true when the
3213 count reaches a particular value. Trace state variables share the
3214 $-syntax of GDB convenience variables, and can appear in both
3215 tracepoint actions and condition expressions. Use the "tvariable"
3216 command to create, and "info tvariables" to view; see "Trace State
3217 Variables" in the manual for more detail.
3221 GDB now includes an option for defining fast tracepoints, which
3222 targets may implement more efficiently, such as by installing a jump
3223 into the target agent rather than a trap instruction. The resulting
3224 speedup can be by two orders of magnitude or more, although the
3225 tradeoff is that some program locations on some target architectures
3226 might not allow fast tracepoint installation, for instance if the
3227 instruction to be replaced is shorter than the jump. To request a
3228 fast tracepoint, use the "ftrace" command, with syntax identical to
3229 the regular trace command.
3231 ** Disconnected tracing
3233 It is now possible to detach GDB from the target while it is running
3234 a trace experiment, then reconnect later to see how the experiment
3235 is going. In addition, a new variable disconnected-tracing lets you
3236 tell the target agent whether to continue running a trace if the
3237 connection is lost unexpectedly.
3241 GDB now has the ability to save the trace buffer into a file, and
3242 then use that file as a target, similarly to you can do with
3243 corefiles. You can select trace frames, print data that was
3244 collected in them, and use tstatus to display the state of the
3245 tracing run at the moment that it was saved. To create a trace
3246 file, use "tsave <filename>", and to use it, do "target tfile
3249 ** Circular trace buffer
3251 You can ask the target agent to handle the trace buffer as a
3252 circular buffer, discarding the oldest trace frames to make room for
3253 newer ones, by setting circular-trace-buffer to on. This feature may
3254 not be available for all target agents.
3259 The disassemble command, when invoked with two arguments, now requires
3260 the arguments to be comma-separated.
3263 The info variables command now displays variable definitions. Files
3264 which only declare a variable are not shown.
3267 The source command is now capable of sourcing Python scripts.
3268 This feature is dependent on the debugger being build with Python
3271 Related to this enhancement is also the introduction of a new command
3272 "set script-extension" (see below).
3274 * New commands (for set/show, see "New options" below)
3276 record save [<FILENAME>]
3277 Save a file (in core file format) containing the process record
3278 execution log for replay debugging at a later time.
3280 record restore <FILENAME>
3281 Restore the process record execution log that was saved at an
3282 earlier time, for replay debugging.
3284 add-inferior [-copies <N>] [-exec <FILENAME>]
3287 clone-inferior [-copies <N>] [ID]
3288 Make a new inferior ready to execute the same program another
3289 inferior has loaded.
3294 maint info program-spaces
3295 List the program spaces loaded into GDB.
3297 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3298 show remote interrupt-sequence
3299 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3300 as the sequence to the remote target in order to interrupt the execution.
3301 Ctrl-C is a default. Some system prefers BREAK which is high level of
3302 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3303 Magic SysRq g. It is BREAK signal and character 'g'.
3305 set remote interrupt-on-connect [on | off]
3306 show remote interrupt-on-connect
3307 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3308 remote target when gdb connects to it. This is needed when you debug
3311 set remotebreak [on | off]
3313 Deprecated. Use "set/show remote interrupt-sequence" instead.
3315 tvariable $NAME [ = EXP ]
3316 Create or modify a trace state variable.
3319 List trace state variables and their values.
3321 delete tvariable $NAME ...
3322 Delete one or more trace state variables.
3325 Evaluate the given expressions without collecting anything into the
3326 trace buffer. (Valid in tracepoint actions only.)
3328 ftrace FN / FILE:LINE / *ADDR
3329 Define a fast tracepoint at the given function, line, or address.
3331 * New expression syntax
3333 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3334 GDB now parses 0b101010 identically with 42.
3338 set follow-exec-mode new|same
3339 show follow-exec-mode
3340 Control whether GDB reuses the same inferior across an exec call or
3341 creates a new one. This is useful to be able to restart the old
3342 executable after the inferior having done an exec call.
3344 set default-collect EXPR, ...
3345 show default-collect
3346 Define a list of expressions to be collected at each tracepoint.
3347 This is a useful way to ensure essential items are not overlooked,
3348 such as registers or a critical global variable.
3350 set disconnected-tracing
3351 show disconnected-tracing
3352 If set to 1, the target is instructed to continue tracing if it
3353 loses its connection to GDB. If 0, the target is to stop tracing
3356 set circular-trace-buffer
3357 show circular-trace-buffer
3358 If set to on, the target is instructed to use a circular trace buffer
3359 and discard the oldest trace frames instead of stopping the trace due
3360 to a full trace buffer. If set to off, the trace stops when the buffer
3361 fills up. Some targets may not support this.
3363 set script-extension off|soft|strict
3364 show script-extension
3365 If set to "off", the debugger does not perform any script language
3366 recognition, and all sourced files are assumed to be GDB scripts.
3367 If set to "soft" (the default), files are sourced according to
3368 filename extension, falling back to GDB scripts if the first
3370 If set to "strict", files are sourced according to filename extension.
3372 set ada trust-PAD-over-XVS on|off
3373 show ada trust-PAD-over-XVS
3374 If off, activate a workaround against a bug in the debugging information
3375 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3376 the GCC sources for more information about the GNAT encoding and
3377 PAD types in particular). It is always safe to set this option to
3378 off, but this introduces a slight performance penalty. The default
3381 * Python API Improvements
3383 ** GDB provides the new class gdb.LazyString. This is useful in
3384 some pretty-printing cases. The new method gdb.Value.lazy_string
3385 provides a simple way to create objects of this type.
3387 ** The fields returned by gdb.Type.fields now have an
3388 `is_base_class' attribute.
3390 ** The new method gdb.Type.range returns the range of an array type.
3392 ** The new method gdb.parse_and_eval can be used to parse and
3393 evaluate an expression.
3395 * New remote packets
3398 Define a trace state variable.
3401 Get the current value of a trace state variable.
3404 Set desired tracing behavior upon disconnection.
3407 Set the trace buffer to be linear or circular.
3410 Get data about the tracepoints currently in use.
3414 Process record now works correctly with hardware watchpoints.
3416 Multiple bug fixes have been made to the mips-irix port, making it
3417 much more reliable. In particular:
3418 - Debugging threaded applications is now possible again. Previously,
3419 GDB would hang while starting the program, or while waiting for
3420 the program to stop at a breakpoint.
3421 - Attaching to a running process no longer hangs.
3422 - An error occurring while loading a core file has been fixed.
3423 - Changing the value of the PC register now works again. This fixes
3424 problems observed when using the "jump" command, or when calling
3425 a function from GDB, or even when assigning a new value to $pc.
3426 - With the "finish" and "return" commands, the return value for functions
3427 returning a small array is now correctly printed.
3428 - It is now possible to break on shared library code which gets executed
3429 during a shared library init phase (code executed while executing
3430 their .init section). Previously, the breakpoint would have no effect.
3431 - GDB is now able to backtrace through the signal handler for
3432 non-threaded programs.
3434 PIE (Position Independent Executable) programs debugging is now supported.
3435 This includes debugging execution of PIC (Position Independent Code) shared
3436 libraries although for that, it should be possible to run such libraries as an
3439 *** Changes in GDB 7.0
3441 * GDB now has an interface for JIT compilation. Applications that
3442 dynamically generate code can create symbol files in memory and register
3443 them with GDB. For users, the feature should work transparently, and
3444 for JIT developers, the interface is documented in the GDB manual in the
3445 "JIT Compilation Interface" chapter.
3447 * Tracepoints may now be conditional. The syntax is as for
3448 breakpoints; either an "if" clause appended to the "trace" command,
3449 or the "condition" command is available. GDB sends the condition to
3450 the target for evaluation using the same bytecode format as is used
3451 for tracepoint actions.
3453 * The disassemble command now supports: an optional /r modifier, print the
3454 raw instructions in hex as well as in symbolic form, and an optional /m
3455 modifier to print mixed source+assembly.
3457 * Process record and replay
3459 In a architecture environment that supports ``process record and
3460 replay'', ``process record and replay'' target can record a log of
3461 the process execution, and replay it with both forward and reverse
3464 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3465 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3466 set execution-direction {forward|reverse}, for targets that support
3469 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3470 feature is available with a native GDB running on kernel version
3473 * GDB now has support for multi-byte and wide character sets on the
3474 target. Strings whose character type is wchar_t, char16_t, or
3475 char32_t are now correctly printed. GDB supports wide- and unicode-
3476 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3477 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3478 `printf'. This feature requires iconv to work properly; if your
3479 system does not have a working iconv, GDB can use GNU libiconv. See
3480 the installation instructions for more information.
3482 * GDB now supports automatic retrieval of shared library files from
3483 remote targets. To use this feature, specify a system root that begins
3484 with the `remote:' prefix, either via the `set sysroot' command or via
3485 the `--with-sysroot' configure-time option.
3487 * "info sharedlibrary" now takes an optional regex of libraries to show,
3488 and it now reports if a shared library has no debugging information.
3490 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3491 now complete on file names.
3493 * When completing in expressions, gdb will attempt to limit
3494 completions to allowable structure or union fields, where appropriate.
3495 For instance, consider:
3497 # struct example { int f1; double f2; };
3498 # struct example variable;
3501 If the user types TAB at the end of this command line, the available
3502 completions will be "f1" and "f2".
3504 * Inlined functions are now supported. They show up in backtraces, and
3505 the "step", "next", and "finish" commands handle them automatically.
3507 * GDB now supports the token-splicing (##) and stringification (#)
3508 operators when expanding macros. It also supports variable-arity
3511 * GDB now supports inspecting extra signal information, exported by
3512 the new $_siginfo convenience variable. The feature is currently
3513 implemented on linux ARM, i386 and amd64.
3515 * GDB can now display the VFP floating point registers and NEON vector
3516 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3517 can provide these registers (requires Linux 2.6.30 or later). Remote
3518 and simulator targets may also provide them.
3520 * New remote packets
3523 Search memory for a sequence of bytes.
3526 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3527 operation over reliable transport links. Use of this packet is
3528 controlled by the `set remote noack-packet' command.
3531 Kill the process with the specified process ID. Use this in preference
3532 to `k' when multiprocess protocol extensions are supported.
3535 Obtains additional operating system information
3539 Read or write additional signal information.
3541 * Removed remote protocol undocumented extension
3543 An undocumented extension to the remote protocol's `S' stop reply
3544 packet that permited the stub to pass a process id was removed.
3545 Remote servers should use the `T' stop reply packet instead.
3547 * GDB now supports multiple function calling conventions according to the
3548 DWARF-2 DW_AT_calling_convention function attribute.
3550 * The SH target utilizes the aforementioned change to distinguish between gcc
3551 and Renesas calling convention. It also adds the new CLI commands
3552 `set/show sh calling-convention'.
3554 * GDB can now read compressed debug sections, as produced by GNU gold
3555 with the --compress-debug-sections=zlib flag.
3557 * 64-bit core files are now supported on AIX.
3559 * Thread switching is now supported on Tru64.
3561 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3562 which will be allocated using malloc later in program execution.
3564 * The qXfer:libraries:read remote procotol packet now allows passing a
3565 list of section offsets.
3567 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3568 conditions handling signals delivered during attach or thread creation
3569 have also been fixed.
3571 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3572 From the user's standpoint, all unqualified instances of True and False
3573 are treated as the standard definitions, regardless of context.
3575 * GDB now parses C++ symbol and type names more flexibly. For
3578 template<typename T> class C { };
3581 GDB will now correctly handle all of:
3583 ptype C<char const *>
3584 ptype C<char const*>
3585 ptype C<const char *>
3586 ptype C<const char*>
3588 * New features in the GDB remote stub, gdbserver
3590 - The "--wrapper" command-line argument tells gdbserver to use a
3591 wrapper program to launch programs for debugging.
3593 - On PowerPC and S/390 targets, it is now possible to use a single
3594 gdbserver executable to debug both 32-bit and 64-bit programs.
3595 (This requires gdbserver itself to be built as a 64-bit executable.)
3597 - gdbserver uses the new noack protocol mode for TCP connections to
3598 reduce communications latency, if also supported and enabled in GDB.
3600 - Support for the sparc64-linux-gnu target is now included in
3603 - The amd64-linux build of gdbserver now supports debugging both
3604 32-bit and 64-bit programs.
3606 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3607 now support hardware watchpoints, and will use them automatically
3612 GDB now has support for scripting using Python. Whether this is
3613 available is determined at configure time.
3615 New GDB commands can now be written in Python.
3617 * Ada tasking support
3619 Ada tasks can now be inspected in GDB. The following commands have
3623 Print the list of Ada tasks.
3625 Print detailed information about task number N.
3627 Print the task number of the current task.
3629 Switch the context of debugging to task number N.
3631 * Support for user-defined prefixed commands. The "define" command can
3632 add new commands to existing prefixes, e.g. "target".
3634 * Multi-inferior, multi-process debugging.
3636 GDB now has generalized support for multi-inferior debugging. See
3637 "Debugging Multiple Inferiors" in the manual for more information.
3638 Although availability still depends on target support, the command
3639 set is more uniform now. The GNU/Linux specific multi-forks support
3640 has been migrated to this new framework. This implied some user
3641 visible changes; see "New commands" and also "Removed commands"
3644 * Target descriptions can now describe the target OS ABI. See the
3645 "Target Description Format" section in the user manual for more
3648 * Target descriptions can now describe "compatible" architectures
3649 to indicate that the target can execute applications for a different
3650 architecture in addition to those for the main target architecture.
3651 See the "Target Description Format" section in the user manual for
3654 * Multi-architecture debugging.
3656 GDB now includes general supports for debugging applications on
3657 hybrid systems that use more than one single processor architecture
3658 at the same time. Each such hybrid architecture still requires
3659 specific support to be added. The only hybrid architecture supported
3660 in this version of GDB is the Cell Broadband Engine.
3662 * GDB now supports integrated debugging of Cell/B.E. applications that
3663 use both the PPU and SPU architectures. To enable support for hybrid
3664 Cell/B.E. debugging, you need to configure GDB to support both the
3665 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3666 --enable-targets configure option.
3668 * Non-stop mode debugging.
3670 For some targets, GDB now supports an optional mode of operation in
3671 which you can examine stopped threads while other threads continue
3672 to execute freely. This is referred to as non-stop mode, with the
3673 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3674 section in the user manual for more information.
3676 To be able to support remote non-stop debugging, a remote stub needs
3677 to implement the non-stop mode remote protocol extensions, as
3678 described in the "Remote Non-Stop" section of the user manual. The
3679 GDB remote stub, gdbserver, has been adjusted to support these
3680 extensions on linux targets.
3682 * New commands (for set/show, see "New options" below)
3684 catch syscall [NAME(S) | NUMBER(S)]
3685 Catch system calls. Arguments, which should be names of system
3686 calls or their numbers, mean catch only those syscalls. Without
3687 arguments, every syscall will be caught. When the inferior issues
3688 any of the specified syscalls, GDB will stop and announce the system
3689 call, both when it is called and when its call returns. This
3690 feature is currently available with a native GDB running on the
3691 Linux Kernel, under the following architectures: x86, x86_64,
3692 PowerPC and PowerPC64.
3694 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3696 Search memory for a sequence of bytes.
3698 maint set python print-stack
3699 maint show python print-stack
3700 Show a stack trace when an error is encountered in a Python script.
3703 Invoke CODE by passing it to the Python interpreter.
3708 These allow macros to be defined, undefined, and listed
3712 Show operating system information about processes.
3715 List the inferiors currently under GDB's control.
3718 Switch focus to inferior number NUM.
3721 Detach from inferior number NUM.
3724 Kill inferior number NUM.
3728 set spu stop-on-load
3729 show spu stop-on-load
3730 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3732 set spu auto-flush-cache
3733 show spu auto-flush-cache
3734 Control whether to automatically flush the software-managed cache
3735 during Cell/B.E. debugging.
3737 set sh calling-convention
3738 show sh calling-convention
3739 Control the calling convention used when calling SH target functions.
3742 show debug timestamp
3743 Control display of timestamps with GDB debugging output.
3745 set disassemble-next-line
3746 show disassemble-next-line
3747 Control display of disassembled source lines or instructions when
3750 set remote noack-packet
3751 show remote noack-packet
3752 Set/show the use of remote protocol QStartNoAckMode packet. See above
3753 under "New remote packets."
3755 set remote query-attached-packet
3756 show remote query-attached-packet
3757 Control use of remote protocol `qAttached' (query-attached) packet.
3759 set remote read-siginfo-object
3760 show remote read-siginfo-object
3761 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3764 set remote write-siginfo-object
3765 show remote write-siginfo-object
3766 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3769 set remote reverse-continue
3770 show remote reverse-continue
3771 Control use of remote protocol 'bc' (reverse-continue) packet.
3773 set remote reverse-step
3774 show remote reverse-step
3775 Control use of remote protocol 'bs' (reverse-step) packet.
3777 set displaced-stepping
3778 show displaced-stepping
3779 Control displaced stepping mode. Displaced stepping is a way to
3780 single-step over breakpoints without removing them from the debuggee.
3781 Also known as "out-of-line single-stepping".
3784 show debug displaced
3785 Control display of debugging info for displaced stepping.
3787 maint set internal-error
3788 maint show internal-error
3789 Control what GDB does when an internal error is detected.
3791 maint set internal-warning
3792 maint show internal-warning
3793 Control what GDB does when an internal warning is detected.
3798 Use a wrapper program to launch programs for debugging.
3800 set multiple-symbols (all|ask|cancel)
3801 show multiple-symbols
3802 The value of this variable can be changed to adjust the debugger behavior
3803 when an expression or a breakpoint location contains an ambiguous symbol
3804 name (an overloaded function name, for instance).
3806 set breakpoint always-inserted
3807 show breakpoint always-inserted
3808 Keep breakpoints always inserted in the target, as opposed to inserting
3809 them when resuming the target, and removing them when the target stops.
3810 This option can improve debugger performance on slow remote targets.
3812 set arm fallback-mode (arm|thumb|auto)
3813 show arm fallback-mode
3814 set arm force-mode (arm|thumb|auto)
3816 These commands control how ARM GDB determines whether instructions
3817 are ARM or Thumb. The default for both settings is auto, which uses
3818 the current CPSR value for instructions without symbols; previous
3819 versions of GDB behaved as if "set arm fallback-mode arm".
3821 set disable-randomization
3822 show disable-randomization
3823 Standalone programs run with the virtual address space randomization enabled
3824 by default on some platforms. This option keeps the addresses stable across
3825 multiple debugging sessions.
3829 Control whether other threads are stopped or not when some thread hits
3834 Requests that asynchronous execution is enabled in the target, if available.
3835 In this case, it's possible to resume target in the background, and interact
3836 with GDB while the target is running. "show target-async" displays the
3837 current state of asynchronous execution of the target.
3839 set target-wide-charset
3840 show target-wide-charset
3841 The target-wide-charset is the name of the character set that GDB
3842 uses when printing characters whose type is wchar_t.
3844 set tcp auto-retry (on|off)
3846 set tcp connect-timeout
3847 show tcp connect-timeout
3848 These commands allow GDB to retry failed TCP connections to a remote stub
3849 with a specified timeout period; this is useful if the stub is launched
3850 in parallel with GDB but may not be ready to accept connections immediately.
3852 set libthread-db-search-path
3853 show libthread-db-search-path
3854 Control list of directories which GDB will search for appropriate
3857 set schedule-multiple (on|off)
3858 show schedule-multiple
3859 Allow GDB to resume all threads of all processes or only threads of
3860 the current process.
3864 Use more aggressive caching for accesses to the stack. This improves
3865 performance of remote debugging (particularly backtraces) without
3866 affecting correctness.
3868 set interactive-mode (on|off|auto)
3869 show interactive-mode
3870 Control whether GDB runs in interactive mode (on) or not (off).
3871 When in interactive mode, GDB waits for the user to answer all
3872 queries. Otherwise, GDB does not wait and assumes the default
3873 answer. When set to auto (the default), GDB determines which
3874 mode to use based on the stdin settings.
3879 For program forks, this is replaced by the new more generic `info
3880 inferiors' command. To list checkpoints, you can still use the
3881 `info checkpoints' command, which was an alias for the `info forks'
3885 Replaced by the new `inferior' command. To switch between
3886 checkpoints, you can still use the `restart' command, which was an
3887 alias for the `fork' command.
3890 This is removed, since some targets don't have a notion of
3891 processes. To switch between processes, you can still use the
3892 `inferior' command using GDB's own inferior number.
3895 For program forks, this is replaced by the new more generic `kill
3896 inferior' command. To delete a checkpoint, you can still use the
3897 `delete checkpoint' command, which was an alias for the `delete
3901 For program forks, this is replaced by the new more generic `detach
3902 inferior' command. To detach a checkpoint, you can still use the
3903 `detach checkpoint' command, which was an alias for the `detach
3906 * New native configurations
3908 x86/x86_64 Darwin i[34567]86-*-darwin*
3910 x86_64 MinGW x86_64-*-mingw*
3914 Lattice Mico32 lm32-*
3915 x86 DICOS i[34567]86-*-dicos*
3916 x86_64 DICOS x86_64-*-dicos*
3919 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3920 (mingw32ce) debugging.
3926 These commands were actually not implemented on any target.
3928 *** Changes in GDB 6.8
3930 * New native configurations
3932 NetBSD/hppa hppa*-*netbsd*
3933 Xtensa GNU/Linux xtensa*-*-linux*
3937 NetBSD/hppa hppa*-*-netbsd*
3938 Xtensa GNU/Lunux xtensa*-*-linux*
3940 * Change in command line behavior -- corefiles vs. process ids.
3942 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3943 attaching to process NUMBER fails, GDB no longer attempts to open a
3944 core file named NUMBER. Attaching to a program using the -c option
3945 is no longer supported. Instead, use the '-p' or '--pid' options.
3947 * GDB can now be built as a native debugger for debugging Windows x86
3948 (mingw32) Portable Executable (PE) programs.
3950 * Pending breakpoints no longer change their number when their address
3953 * GDB now supports breakpoints with multiple locations,
3954 including breakpoints on C++ constructors, inside C++ templates,
3955 and in inlined functions.
3957 * GDB's ability to debug optimized code has been improved. GDB more
3958 accurately identifies function bodies and lexical blocks that occupy
3959 more than one contiguous range of addresses.
3961 * Target descriptions can now describe registers for PowerPC.
3963 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3964 registers on PowerPC targets.
3966 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3967 targets even when the libthread_db library is not available.
3969 * The GDB remote stub, gdbserver, now supports the new file transfer
3970 commands (remote put, remote get, and remote delete).
3972 * The GDB remote stub, gdbserver, now supports run and attach in
3973 extended-remote mode.
3975 * hppa*64*-*-hpux11* target broken
3976 The debugger is unable to start a program and fails with the following
3977 error: "Error trying to get information about dynamic linker".
3978 The gdb-6.7 release is also affected.
3980 * GDB now supports the --enable-targets= configure option to allow
3981 building a single GDB executable that supports multiple remote
3982 target architectures.
3984 * GDB now supports debugging C and C++ programs which use the
3985 Decimal Floating Point extension. In addition, the PowerPC target
3986 now has a set of pseudo-registers to inspect decimal float values
3987 stored in two consecutive float registers.
3989 * The -break-insert MI command can optionally create pending
3992 * Improved support for debugging Ada
3993 Many improvements to the Ada language support have been made. These
3995 - Better support for Ada2005 interface types
3996 - Improved handling of arrays and slices in general
3997 - Better support for Taft-amendment types
3998 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4000 - Improved command completion in Ada
4003 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4008 set print frame-arguments (all|scalars|none)
4009 show print frame-arguments
4010 The value of this variable can be changed to control which argument
4011 values should be printed by the debugger when displaying a frame.
4016 Transfer files to and from a remote target, and delete remote files.
4023 Transfer files to and from a remote target, and delete remote files.
4025 * New remote packets
4032 Open, close, read, write, and delete files on the remote system.
4035 Attach to an existing process on the remote system, in extended-remote
4039 Run a new process on the remote system, in extended-remote mode.
4041 *** Changes in GDB 6.7
4043 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4044 bfd, libiberty and opcodes, as revealed by static analysis donated by
4045 Coverity, Inc. (http://scan.coverity.com).
4047 * When looking up multiply-defined global symbols, GDB will now prefer the
4048 symbol definition in the current shared library if it was built using the
4049 -Bsymbolic linker option.
4051 * When the Text User Interface (TUI) is not configured, GDB will now
4052 recognize the -tui command-line option and print a message that the TUI
4055 * The GDB remote stub, gdbserver, now has lower overhead for high
4056 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4058 * GDB for MIPS targets now autodetects whether a remote target provides
4059 32-bit or 64-bit register values.
4061 * Support for C++ member pointers has been improved.
4063 * GDB now understands XML target descriptions, which specify the
4064 target's overall architecture. GDB can read a description from
4065 a local file or over the remote serial protocol.
4067 * Vectors of single-byte data use a new integer type which is not
4068 automatically displayed as character or string data.
4070 * The /s format now works with the print command. It displays
4071 arrays of single-byte integers and pointers to single-byte integers
4074 * Target descriptions can now describe target-specific registers,
4075 for architectures which have implemented the support (currently
4076 only ARM, M68K, and MIPS).
4078 * GDB and the GDB remote stub, gdbserver, now support the XScale
4081 * The GDB remote stub, gdbserver, has been updated to support
4082 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4083 has been rewritten to use the standard GDB remote protocol.
4085 * GDB can now step into C++ functions which are called through thunks.
4087 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4089 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4090 layout. It also supports a TextSeg= and DataSeg= response when only
4091 segment base addresses (rather than offsets) are available.
4093 * The /i format now outputs any trailing branch delay slot instructions
4094 immediately following the last instruction within the count specified.
4096 * The GDB remote protocol "T" stop reply packet now supports a
4097 "library" response. Combined with the new "qXfer:libraries:read"
4098 packet, this response allows GDB to debug shared libraries on targets
4099 where the operating system manages the list of loaded libraries (e.g.
4100 Windows and SymbianOS).
4102 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4103 (DLLs) on Windows and Windows CE targets.
4105 * GDB now supports a faster verification that a .debug file matches its binary
4106 according to its build-id signature, if the signature is present.
4112 Enable or disable hardware flow control (RTS/CTS) on the serial port
4113 when debugging using remote targets.
4115 set mem inaccessible-by-default
4116 show mem inaccessible-by-default
4117 If the target supplies a memory map, for instance via the remote
4118 protocol's "qXfer:memory-map:read" packet, setting this variable
4119 prevents GDB from accessing memory outside the memory map. This
4120 is useful for targets with memory mapped registers or which react
4121 badly to accesses of unmapped address space.
4123 set breakpoint auto-hw
4124 show breakpoint auto-hw
4125 If the target supplies a memory map, for instance via the remote
4126 protocol's "qXfer:memory-map:read" packet, setting this variable
4127 lets GDB use hardware breakpoints automatically for memory regions
4128 where it can not use software breakpoints. This covers both the
4129 "break" command and internal breakpoints used for other commands
4130 including "next" and "finish".
4133 catch exception unhandled
4134 Stop the program execution when Ada exceptions are raised.
4137 Stop the program execution when an Ada assertion failed.
4141 Set an alternate system root for target files. This is a more
4142 general version of "set solib-absolute-prefix", which is now
4143 an alias to "set sysroot".
4146 Provide extended SPU facility status information. This set of
4147 commands is available only when debugging the Cell/B.E. SPU
4150 * New native configurations
4152 OpenBSD/sh sh*-*openbsd*
4155 unset tdesc filename
4157 Use the specified local file as an XML target description, and do
4158 not query the target for its built-in description.
4162 OpenBSD/sh sh*-*-openbsd*
4163 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4164 Toshiba Media Processor mep-elf
4166 * New remote packets
4169 Ignore the specified signals; pass them directly to the debugged program
4170 without stopping other threads or reporting them to GDB.
4172 qXfer:features:read:
4173 Read an XML target description from the target, which describes its
4178 Read or write contents of an spufs file on the target system. These
4179 packets are available only on the Cell/B.E. SPU architecture.
4181 qXfer:libraries:read:
4182 Report the loaded shared libraries. Combined with new "T" packet
4183 response, this packet allows GDB to debug shared libraries on
4184 targets where the operating system manages the list of loaded
4185 libraries (e.g. Windows and SymbianOS).
4189 Support for these obsolete configurations has been removed.
4197 i[34567]86-*-lynxos*
4198 i[34567]86-*-netware*
4199 i[34567]86-*-sco3.2v5*
4200 i[34567]86-*-sco3.2v4*
4202 i[34567]86-*-sysv4.2*
4205 i[34567]86-*-unixware2*
4206 i[34567]86-*-unixware*
4215 * Other removed features
4222 Various m68k-only ROM monitors.
4229 Various Renesas ROM monitors and debugging interfaces for SH and
4234 Support for a Macraigor serial interface to on-chip debugging.
4235 GDB does not directly support the newer parallel or USB
4240 A debug information format. The predecessor to DWARF 2 and
4241 DWARF 3, which are still supported.
4243 Support for the HP aCC compiler on HP-UX/PA-RISC
4245 SOM-encapsulated symbolic debugging information, automatic
4246 invocation of pxdb, and the aCC custom C++ ABI. This does not
4247 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4248 with aCC can still be debugged on an assembly level.
4250 MIPS ".pdr" sections
4252 A MIPS-specific format used to describe stack frame layout
4253 in debugging information.
4257 GDB could work with an older version of Guile to debug
4258 the interpreter and Scheme programs running in it.
4260 set mips stack-arg-size
4261 set mips saved-gpreg-size
4263 Use "set mips abi" to control parameter passing for MIPS.
4265 *** Changes in GDB 6.6
4270 Cell Broadband Engine SPU spu-elf
4272 * GDB can now be configured as a cross-debugger targeting native Windows
4273 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4274 running on a Windows system over TCP/IP to debug Windows programs.
4276 * The GDB remote stub, gdbserver, has been updated to support Windows and
4277 Cygwin debugging. Both single-threaded and multi-threaded programs are
4280 * The "set trust-readonly-sections" command works again. This command was
4281 broken in GDB 6.3, 6.4, and 6.5.
4283 * The "load" command now supports writing to flash memory, if the remote
4284 stub provides the required support.
4286 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4287 longer requires symbolic debug information (e.g. DWARF-2).
4292 unset substitute-path
4293 show substitute-path
4294 Manage a list of substitution rules that GDB uses to rewrite the name
4295 of the directories where the sources are located. This can be useful
4296 for instance when the sources were moved to a different location
4297 between compilation and debugging.
4301 Print each CLI command as it is executed. Each command is prefixed with
4302 a number of `+' symbols representing the nesting depth.
4303 The source command now has a `-v' option to enable the same feature.
4307 The ARM Demon monitor support (RDP protocol, "target rdp").
4309 Kernel Object Display, an embedded debugging feature which only worked with
4310 an obsolete version of Cisco IOS.
4312 The 'set download-write-size' and 'show download-write-size' commands.
4314 * New remote packets
4317 Tell a stub about GDB client features, and request remote target features.
4318 The first feature implemented is PacketSize, which allows the target to
4319 specify the size of packets it can handle - to minimize the number of
4320 packets required and improve performance when connected to a remote
4324 Fetch an OS auxilliary vector from the remote stub. This packet is a
4325 more efficient replacement for qPart:auxv:read.
4327 qXfer:memory-map:read:
4328 Fetch a memory map from the remote stub, including information about
4329 RAM, ROM, and flash memory devices.
4334 Erase and program a flash memory device.
4336 * Removed remote packets
4339 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4340 used it, and only gdbserver implemented it.
4342 *** Changes in GDB 6.5
4346 Renesas M32C/M16C m32c-elf
4348 Morpho Technologies ms1 ms1-elf
4352 init-if-undefined Initialize a convenience variable, but
4353 only if it doesn't already have a value.
4355 The following commands are presently only implemented for native GNU/Linux:
4357 checkpoint Save a snapshot of the program state.
4359 restart <n> Return the program state to a
4360 previously saved state.
4362 info checkpoints List currently saved checkpoints.
4364 delete-checkpoint <n> Delete a previously saved checkpoint.
4366 set|show detach-on-fork Tell gdb whether to detach from a newly
4367 forked process, or to keep debugging it.
4369 info forks List forks of the user program that
4370 are available to be debugged.
4372 fork <n> Switch to debugging one of several
4373 forks of the user program that are
4374 available to be debugged.
4376 delete-fork <n> Delete a fork from the list of forks
4377 that are available to be debugged (and
4378 kill the forked process).
4380 detach-fork <n> Delete a fork from the list of forks
4381 that are available to be debugged (and
4382 allow the process to continue).
4386 Morpho Technologies ms2 ms1-elf
4388 * Improved Windows host support
4390 GDB now builds as a cross debugger hosted on i686-mingw32, including
4391 native console support, and remote communications using either
4392 network sockets or serial ports.
4394 * Improved Modula-2 language support
4396 GDB can now print most types in the Modula-2 syntax. This includes:
4397 basic types, set types, record types, enumerated types, range types,
4398 pointer types and ARRAY types. Procedure var parameters are correctly
4399 printed and hexadecimal addresses and character constants are also
4400 written in the Modula-2 syntax. Best results can be obtained by using
4401 GNU Modula-2 together with the -gdwarf-2 command line option.
4405 The ARM rdi-share module.
4407 The Netware NLM debug server.
4409 *** Changes in GDB 6.4
4411 * New native configurations
4413 OpenBSD/arm arm*-*-openbsd*
4414 OpenBSD/mips64 mips64-*-openbsd*
4418 Morpho Technologies ms1 ms1-elf
4420 * New command line options
4422 --batch-silent As for --batch, but totally silent.
4423 --return-child-result The debugger will exist with the same value
4424 the child (debugged) program exited with.
4425 --eval-command COMMAND, -ex COMMAND
4426 Execute a single GDB CLI command. This may be
4427 specified multiple times and in conjunction
4428 with the --command (-x) option.
4430 * Deprecated commands removed
4432 The following commands, that were deprecated in 2000, have been
4436 set|show arm disassembly-flavor set|show arm disassembler
4437 othernames set arm disassembler
4438 set|show remotedebug set|show debug remote
4439 set|show archdebug set|show debug arch
4440 set|show eventdebug set|show debug event
4443 * New BSD user-level threads support
4445 It is now possible to debug programs using the user-level threads
4446 library on OpenBSD and FreeBSD. Currently supported (target)
4449 FreeBSD/amd64 x86_64-*-freebsd*
4450 FreeBSD/i386 i386-*-freebsd*
4451 OpenBSD/i386 i386-*-openbsd*
4453 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4454 are not yet supported.
4456 * New support for Matsushita MN10300 w/sim added
4457 (Work in progress). mn10300-elf.
4459 * REMOVED configurations and files
4461 VxWorks and the XDR protocol *-*-vxworks
4462 Motorola MCORE mcore-*-*
4463 National Semiconductor NS32000 ns32k-*-*
4465 * New "set print array-indexes" command
4467 After turning this setting "on", GDB prints the index of each element
4468 when displaying arrays. The default is "off" to preserve the previous
4471 * VAX floating point support
4473 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4475 * User-defined command support
4477 In addition to using $arg0..$arg9 for argument passing, it is now possible
4478 to use $argc to determine now many arguments have been passed. See the
4479 section on user-defined commands in the user manual for more information.
4481 *** Changes in GDB 6.3:
4483 * New command line option
4485 GDB now accepts -l followed by a number to set the timeout for remote
4488 * GDB works with GCC -feliminate-dwarf2-dups
4490 GDB now supports a more compact representation of DWARF-2 debug
4491 information using DW_FORM_ref_addr references. These are produced
4492 by GCC with the option -feliminate-dwarf2-dups and also by some
4493 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4494 to use -feliminate-dwarf2-dups.
4496 * Internationalization
4498 When supported by the host system, GDB will be built with
4499 internationalization (libintl). The task of marking up the sources is
4500 continued, we're looking forward to our first translation.
4504 Initial support for debugging programs compiled with the GNAT
4505 implementation of the Ada programming language has been integrated
4506 into GDB. In this release, support is limited to expression evaluation.
4508 * New native configurations
4510 GNU/Linux/m32r m32r-*-linux-gnu
4514 GDB's remote protocol now includes support for the 'p' packet. This
4515 packet is used to fetch individual registers from a remote inferior.
4517 * END-OF-LIFE registers[] compatibility module
4519 GDB's internal register infrastructure has been completely rewritten.
4520 The new infrastructure making possible the implementation of key new
4521 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4524 GDB 6.3 will be the last release to include the the registers[]
4525 compatibility module that allowed out-of-date configurations to
4526 continue to work. This change directly impacts the following
4536 powerpc bdm protocol
4538 Unless there is activity to revive these configurations, they will be
4539 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4541 * OBSOLETE configurations and files
4543 Configurations that have been declared obsolete in this release have
4544 been commented out. Unless there is activity to revive these
4545 configurations, the next release of GDB will have their sources
4546 permanently REMOVED.
4555 *** Changes in GDB 6.2.1:
4557 * MIPS `break main; run' gave an heuristic-fence-post warning
4559 When attempting to run even a simple program, a warning about
4560 heuristic-fence-post being hit would be reported. This problem has
4563 * MIPS IRIX 'long double' crashed GDB
4565 When examining a long double variable, GDB would get a segmentation
4566 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4567 IRIX long double values).
4571 A bug in the VAX stack code was causing problems with the "next"
4572 command. This problem has been fixed.
4574 *** Changes in GDB 6.2:
4576 * Fix for ``many threads''
4578 On GNU/Linux systems that use the NPTL threads library, a program
4579 rapidly creating and deleting threads would confuse GDB leading to the
4582 ptrace: No such process.
4583 thread_db_get_info: cannot get thread info: generic error
4585 This problem has been fixed.
4587 * "-async" and "-noasync" options removed.
4589 Support for the broken "-noasync" option has been removed (it caused
4592 * New ``start'' command.
4594 This command runs the program until the begining of the main procedure.
4596 * New BSD Kernel Data Access Library (libkvm) interface
4598 Using ``target kvm'' it is now possible to debug kernel core dumps and
4599 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4600 platforms. Currently supported (native-only) configurations are:
4602 FreeBSD/amd64 x86_64-*-freebsd*
4603 FreeBSD/i386 i?86-*-freebsd*
4604 NetBSD/i386 i?86-*-netbsd*
4605 NetBSD/m68k m68*-*-netbsd*
4606 NetBSD/sparc sparc-*-netbsd*
4607 OpenBSD/amd64 x86_64-*-openbsd*
4608 OpenBSD/i386 i?86-*-openbsd*
4609 OpenBSD/m68k m68*-openbsd*
4610 OpenBSD/sparc sparc-*-openbsd*
4612 * Signal trampoline code overhauled
4614 Many generic problems with GDB's signal handling code have been fixed.
4615 These include: backtraces through non-contiguous stacks; recognition
4616 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4617 call; backtrace through a signal trampoline; step into and out of
4618 signal handlers; and single-stepping in the signal trampoline.
4620 Please note that kernel bugs are a limiting factor here. These
4621 features have been shown to work on an s390 GNU/Linux system that
4622 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4624 * Cygwin support for DWARF 2 added.
4626 * New native configurations
4628 GNU/Linux/hppa hppa*-*-linux*
4629 OpenBSD/hppa hppa*-*-openbsd*
4630 OpenBSD/m68k m68*-*-openbsd*
4631 OpenBSD/m88k m88*-*-openbsd*
4632 OpenBSD/powerpc powerpc-*-openbsd*
4633 NetBSD/vax vax-*-netbsd*
4634 OpenBSD/vax vax-*-openbsd*
4636 * END-OF-LIFE frame compatibility module
4638 GDB's internal frame infrastructure has been completely rewritten.
4639 The new infrastructure making it possible to support key new features
4640 including DWARF 2 Call Frame Information. To aid in the task of
4641 migrating old configurations to this new infrastructure, a
4642 compatibility module, that allowed old configurations to continue to
4643 work, was also included.
4645 GDB 6.2 will be the last release to include this frame compatibility
4646 module. This change directly impacts the following configurations:
4656 Unless there is activity to revive these configurations, they will be
4657 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4659 * REMOVED configurations and files
4661 Sun 3, running SunOS 3 m68*-*-sunos3*
4662 Sun 3, running SunOS 4 m68*-*-sunos4*
4663 Sun 2, running SunOS 3 m68000-*-sunos3*
4664 Sun 2, running SunOS 4 m68000-*-sunos4*
4665 Motorola 680x0 running LynxOS m68*-*-lynxos*
4666 AT&T 3b1/Unix pc m68*-att-*
4667 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4668 decstation mips-dec-* mips-little-*
4669 riscos mips-*-riscos* mips-*-sysv*
4670 sonymips mips-sony-*
4671 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4673 *** Changes in GDB 6.1.1:
4675 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4677 The TUI (Text-mode User Interface) is now built as part of a default
4678 GDB configuration. It is enabled by either selecting the TUI with the
4679 command line option "-i=tui" or by running the separate "gdbtui"
4680 program. For more information on the TUI, see the manual "Debugging
4683 * Pending breakpoint support (also included in GDB 6.1)
4685 Support has been added to allow you to specify breakpoints in shared
4686 libraries that have not yet been loaded. If a breakpoint location
4687 cannot be found, and the "breakpoint pending" option is set to auto,
4688 GDB queries you if you wish to make the breakpoint pending on a future
4689 shared-library load. If and when GDB resolves the breakpoint symbol,
4690 the pending breakpoint is removed as one or more regular breakpoints
4693 Pending breakpoints are very useful for GCJ Java debugging.
4695 * Fixed ISO-C build problems
4697 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4698 non ISO-C code that stopped them being built using a more strict ISO-C
4699 compiler (e.g., IBM's C compiler).
4701 * Fixed build problem on IRIX 5
4703 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4704 wasn't able to compile compile on an IRIX 5 system.
4706 * Added execute permission to gdb/gdbserver/configure
4708 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4709 permission. This bug would cause configure to fail on a number of
4710 systems (Solaris, IRIX). Ref: server/519.
4712 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4714 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4715 has been updated to use constant array sizes.
4717 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4719 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4720 its generated DWARF Call Frame Info. This encoding was causing GDB to
4721 panic, that panic has been fixed. Ref: gdb/1628.
4723 * Fixed a problem when examining parameters in shared library code.
4725 When examining parameters in optimized shared library code generated
4726 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4727 not available''. GDB now correctly displays the variable's value.
4729 *** Changes in GDB 6.1:
4731 * Removed --with-mmalloc
4733 Support for the mmalloc memory manager has been removed, as it
4734 conflicted with the internal gdb byte cache.
4736 * Changes in AMD64 configurations
4738 The AMD64 target now includes the %cs and %ss registers. As a result
4739 the AMD64 remote protocol has changed; this affects the floating-point
4740 and SSE registers. If you rely on those registers for your debugging,
4741 you should upgrade gdbserver on the remote side.
4743 * Revised SPARC target
4745 The SPARC target has been completely revised, incorporating the
4746 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4747 support for LynxOS and SunOS 4 has been dropped. Calling functions
4748 from within GDB on operating systems with a non-executable stack
4749 (Solaris, OpenBSD) now works.
4753 GDB has a new C++ demangler which does a better job on the mangled
4754 names generated by current versions of g++. It also runs faster, so
4755 with this and other changes gdb should now start faster on large C++
4758 * DWARF 2 Location Expressions
4760 GDB support for location expressions has been extended to support function
4761 arguments and frame bases. Older versions of GDB could crash when they
4764 * C++ nested types and namespaces
4766 GDB's support for nested types and namespaces in C++ has been
4767 improved, especially if you use the DWARF 2 debugging format. (This
4768 is the default for recent versions of GCC on most platforms.)
4769 Specifically, if you have a class "Inner" defined within a class or
4770 namespace "Outer", then GDB realizes that the class's name is
4771 "Outer::Inner", not simply "Inner". This should greatly reduce the
4772 frequency of complaints about not finding RTTI symbols. In addition,
4773 if you are stopped at inside of a function defined within a namespace,
4774 GDB modifies its name lookup accordingly.
4776 * New native configurations
4778 NetBSD/amd64 x86_64-*-netbsd*
4779 OpenBSD/amd64 x86_64-*-openbsd*
4780 OpenBSD/alpha alpha*-*-openbsd*
4781 OpenBSD/sparc sparc-*-openbsd*
4782 OpenBSD/sparc64 sparc64-*-openbsd*
4784 * New debugging protocols
4786 M32R with SDI protocol m32r-*-elf*
4788 * "set prompt-escape-char" command deleted.
4790 The command "set prompt-escape-char" has been deleted. This command,
4791 and its very obscure effet on GDB's prompt, was never documented,
4792 tested, nor mentioned in the NEWS file.
4794 * OBSOLETE configurations and files
4796 Configurations that have been declared obsolete in this release have
4797 been commented out. Unless there is activity to revive these
4798 configurations, the next release of GDB will have their sources
4799 permanently REMOVED.
4801 Sun 3, running SunOS 3 m68*-*-sunos3*
4802 Sun 3, running SunOS 4 m68*-*-sunos4*
4803 Sun 2, running SunOS 3 m68000-*-sunos3*
4804 Sun 2, running SunOS 4 m68000-*-sunos4*
4805 Motorola 680x0 running LynxOS m68*-*-lynxos*
4806 AT&T 3b1/Unix pc m68*-att-*
4807 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4808 decstation mips-dec-* mips-little-*
4809 riscos mips-*-riscos* mips-*-sysv*
4810 sonymips mips-sony-*
4811 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4813 * REMOVED configurations and files
4815 SGI Irix-4.x mips-sgi-irix4 or iris4
4816 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4817 Z8000 simulator z8k-zilog-none or z8ksim
4818 Matsushita MN10200 w/simulator mn10200-*-*
4819 H8/500 simulator h8500-hitachi-hms or h8500hms
4820 HP/PA running BSD hppa*-*-bsd*
4821 HP/PA running OSF/1 hppa*-*-osf*
4822 HP/PA Pro target hppa*-*-pro*
4823 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4824 386BSD i[3456]86-*-bsd*
4825 Sequent family i[3456]86-sequent-sysv4*
4826 i[3456]86-sequent-sysv*
4827 i[3456]86-sequent-bsd*
4828 SPARC running LynxOS sparc-*-lynxos*
4829 SPARC running SunOS 4 sparc-*-sunos4*
4830 Tsqware Sparclet sparclet-*-*
4831 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4833 *** Changes in GDB 6.0:
4837 Support for debugging the Objective-C programming language has been
4838 integrated into GDB.
4840 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4842 DWARF 2's Call Frame Information makes available compiler generated
4843 information that more exactly describes the program's run-time stack.
4844 By using this information, GDB is able to provide more robust stack
4847 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4848 have been updated to use a new backtrace mechanism which includes
4849 DWARF 2 CFI support.
4853 GDB's remote protocol has been extended to include support for hosted
4854 file I/O (where the remote target uses GDB's file system). See GDB's
4855 remote protocol documentation for details.
4857 * All targets using the new architecture framework.
4859 All of GDB's targets have been updated to use the new internal
4860 architecture framework. The way is now open for future GDB releases
4861 to include cross-architecture native debugging support (i386 on amd64,
4864 * GNU/Linux's Thread Local Storage (TLS)
4866 GDB now includes support for for the GNU/Linux implementation of
4867 per-thread variables.
4869 * GNU/Linux's Native POSIX Thread Library (NPTL)
4871 GDB's thread code has been updated to work with either the new
4872 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4874 * Separate debug info.
4876 GDB, in conjunction with BINUTILS, now supports a mechanism for
4877 automatically loading debug information from a separate file. Instead
4878 of shipping full debug and non-debug versions of system libraries,
4879 system integrators can now instead ship just the stripped libraries
4880 and optional debug files.
4882 * DWARF 2 Location Expressions
4884 DWARF 2 Location Expressions allow the compiler to more completely
4885 describe the location of variables (even in optimized code) to the
4888 GDB now includes preliminary support for location expressions (support
4889 for DW_OP_piece is still missing).
4893 A number of long standing bugs that caused GDB to die while starting a
4894 Java application have been fixed. GDB's Java support is now
4895 considered "useable".
4897 * GNU/Linux support for fork, vfork, and exec.
4899 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4900 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4903 * GDB supports logging output to a file
4905 There are two new commands, "set logging" and "show logging", which can be
4906 used to capture GDB's output to a file.
4908 * The meaning of "detach" has changed for gdbserver
4910 The "detach" command will now resume the application, as documented. To
4911 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4914 * d10v, m68hc11 `regs' command deprecated
4916 The `info registers' command has been updated so that it displays the
4917 registers using a format identical to the old `regs' command.
4921 A new command, "maint set profile on/off", has been added. This command can
4922 be used to enable or disable profiling while running GDB, to profile a
4923 session or a set of commands. In addition there is a new configure switch,
4924 "--enable-profiling", which will cause GDB to be compiled with profiling
4925 data, for more informative profiling results.
4927 * Default MI syntax changed to "mi2".
4929 The default MI (machine interface) syntax, enabled by the command line
4930 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4931 "mi1", can be enabled by specifying the option "-i=mi1".
4933 Support for the original "mi0" syntax (included in GDB 5.0) has been
4936 Fix for gdb/192: removed extraneous space when displaying frame level.
4937 Fix for gdb/672: update changelist is now output in mi list format.
4938 Fix for gdb/702: a -var-assign that updates the value now shows up
4939 in a subsequent -var-update.
4941 * New native configurations.
4943 FreeBSD/amd64 x86_64-*-freebsd*
4945 * Multi-arched targets.
4947 HP/PA HPUX11 hppa*-*-hpux*
4948 Renesas M32R/D w/simulator m32r-*-elf*
4950 * OBSOLETE configurations and files
4952 Configurations that have been declared obsolete in this release have
4953 been commented out. Unless there is activity to revive these
4954 configurations, the next release of GDB will have their sources
4955 permanently REMOVED.
4957 Z8000 simulator z8k-zilog-none or z8ksim
4958 Matsushita MN10200 w/simulator mn10200-*-*
4959 H8/500 simulator h8500-hitachi-hms or h8500hms
4960 HP/PA running BSD hppa*-*-bsd*
4961 HP/PA running OSF/1 hppa*-*-osf*
4962 HP/PA Pro target hppa*-*-pro*
4963 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4964 Sequent family i[3456]86-sequent-sysv4*
4965 i[3456]86-sequent-sysv*
4966 i[3456]86-sequent-bsd*
4967 Tsqware Sparclet sparclet-*-*
4968 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4970 * REMOVED configurations and files
4973 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4974 IBM AIX PS/2 i[3456]86-*-aix
4975 i386 running Mach 3.0 i[3456]86-*-mach3*
4976 i386 running Mach i[3456]86-*-mach*
4977 i386 running OSF/1 i[3456]86-*osf1mk*
4978 HP/Apollo 68k Family m68*-apollo*-sysv*,
4980 m68*-hp-bsd*, m68*-hp-hpux*
4981 Argonaut Risc Chip (ARC) arc-*-*
4982 Mitsubishi D30V d30v-*-*
4983 Fujitsu FR30 fr30-*-elf*
4984 OS/9000 i[34]86-*-os9k
4985 I960 with MON960 i960-*-coff
4987 * MIPS $fp behavior changed
4989 The convenience variable $fp, for the MIPS, now consistently returns
4990 the address of the current frame's base. Previously, depending on the
4991 context, $fp could refer to either $sp or the current frame's base
4992 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4993 The GNU Source-Level Debugger''.
4995 *** Changes in GDB 5.3:
4997 * GNU/Linux shared library multi-threaded performance improved.
4999 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5000 `/proc', in preference to `ptrace' for memory reads. This may result
5001 in an improvement in the start-up time of multi-threaded, shared
5002 library applications when run under GDB. One GDB user writes: ``loads
5003 shared libs like mad''.
5005 * ``gdbserver'' now supports multi-threaded applications on some targets
5007 Support for debugging multi-threaded applications which use
5008 the GNU/Linux LinuxThreads package has been added for
5009 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5010 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5012 * GDB now supports C/C++ preprocessor macros.
5014 GDB now expands preprocessor macro invocations in C/C++ expressions,
5015 and provides various commands for showing macro definitions and how
5018 The new command `macro expand EXPRESSION' expands any macro
5019 invocations in expression, and shows the result.
5021 The new command `show macro MACRO-NAME' shows the definition of the
5022 macro named MACRO-NAME, and where it was defined.
5024 Most compilers don't include information about macros in the debugging
5025 information by default. In GCC 3.1, for example, you need to compile
5026 your program with the options `-gdwarf-2 -g3'. If the macro
5027 information is present in the executable, GDB will read it.
5029 * Multi-arched targets.
5031 DEC Alpha (partial) alpha*-*-*
5032 DEC VAX (partial) vax-*-*
5034 National Semiconductor NS32000 (partial) ns32k-*-*
5035 Motorola 68000 (partial) m68k-*-*
5036 Motorola MCORE mcore-*-*
5040 Fujitsu FRV architecture added by Red Hat frv*-*-*
5043 * New native configurations
5045 Alpha NetBSD alpha*-*-netbsd*
5046 SH NetBSD sh*-*-netbsdelf*
5047 MIPS NetBSD mips*-*-netbsd*
5048 UltraSPARC NetBSD sparc64-*-netbsd*
5050 * OBSOLETE configurations and files
5052 Configurations that have been declared obsolete in this release have
5053 been commented out. Unless there is activity to revive these
5054 configurations, the next release of GDB will have their sources
5055 permanently REMOVED.
5057 Mitsubishi D30V d30v-*-*
5058 OS/9000 i[34]86-*-os9k
5059 IBM AIX PS/2 i[3456]86-*-aix
5060 Fujitsu FR30 fr30-*-elf*
5061 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5062 Argonaut Risc Chip (ARC) arc-*-*
5063 i386 running Mach 3.0 i[3456]86-*-mach3*
5064 i386 running Mach i[3456]86-*-mach*
5065 i386 running OSF/1 i[3456]86-*osf1mk*
5066 HP/Apollo 68k Family m68*-apollo*-sysv*,
5068 m68*-hp-bsd*, m68*-hp-hpux*
5069 I960 with MON960 i960-*-coff
5071 * OBSOLETE languages
5073 CHILL, a Pascal like language used by telecommunications companies.
5075 * REMOVED configurations and files
5077 AMD 29k family via UDI a29k-amd-udi, udi29k
5078 A29K VxWorks a29k-*-vxworks
5079 AMD 29000 embedded, using EBMON a29k-none-none
5080 AMD 29000 embedded with COFF a29k-none-coff
5081 AMD 29000 embedded with a.out a29k-none-aout
5083 testsuite/gdb.hp/gdb.threads-hp/ directory
5085 * New command "set max-user-call-depth <nnn>"
5087 This command allows the user to limit the call depth of user-defined
5088 commands. The default is 1024.
5090 * Changes in FreeBSD/i386 native debugging.
5092 Support for the "generate-core-file" has been added.
5094 * New commands "dump", "append", and "restore".
5096 These commands allow data to be copied from target memory
5097 to a bfd-format or binary file (dump and append), and back
5098 from a file into memory (restore).
5100 * Improved "next/step" support on multi-processor Alpha Tru64.
5102 The previous single-step mechanism could cause unpredictable problems,
5103 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5104 of a software single-step mechanism prevents this.
5106 *** Changes in GDB 5.2.1:
5114 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5115 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5116 Fix, by Joel Brobecker imported from mainline.
5118 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5119 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5120 Fix, by Fred Fish, imported from mainline.
5122 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5123 Surprisingly enough, it works now.
5124 By Michal Ludvig, imported from mainline.
5126 i386 hardware watchpoint support:
5127 avoid misses on second run for some targets.
5128 By Pierre Muller, imported from mainline.
5130 *** Changes in GDB 5.2:
5132 * New command "set trust-readonly-sections on[off]".
5134 This command is a hint that tells gdb that read-only sections
5135 really are read-only (ie. that their contents will not change).
5136 In this mode, gdb will go to the object file rather than the
5137 target to read memory from read-only sections (such as ".text").
5138 This can be a significant performance improvement on some
5139 (notably embedded) targets.
5141 * New command "generate-core-file" (or "gcore").
5143 This new gdb command allows the user to drop a core file of the child
5144 process state at any time. So far it's been implemented only for
5145 GNU/Linux and Solaris, but should be relatively easily ported to other
5146 hosts. Argument is core file name (defaults to core.<pid>).
5148 * New command line option
5150 GDB now accepts --pid or -p followed by a process id.
5152 * Change in command line behavior -- corefiles vs. process ids.
5154 There is a subtle behavior in the way in which GDB handles
5155 command line arguments. The first non-flag argument is always
5156 a program to debug, but the second non-flag argument may either
5157 be a corefile or a process id. Previously, GDB would attempt to
5158 open the second argument as a corefile, and if that failed, would
5159 issue a superfluous error message and then attempt to attach it as
5160 a process. Now, if the second argument begins with a non-digit,
5161 it will be treated as a corefile. If it begins with a digit,
5162 GDB will attempt to attach it as a process, and if no such process
5163 is found, will then attempt to open it as a corefile.
5165 * Changes in ARM configurations.
5167 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5168 configuration is fully multi-arch.
5170 * New native configurations
5172 ARM NetBSD arm*-*-netbsd*
5173 x86 OpenBSD i[3456]86-*-openbsd*
5174 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5175 Sparc64 running FreeBSD sparc64-*-freebsd*
5179 Sanyo XStormy16 xstormy16-elf
5181 * OBSOLETE configurations and files
5183 Configurations that have been declared obsolete in this release have
5184 been commented out. Unless there is activity to revive these
5185 configurations, the next release of GDB will have their sources
5186 permanently REMOVED.
5188 AMD 29k family via UDI a29k-amd-udi, udi29k
5189 A29K VxWorks a29k-*-vxworks
5190 AMD 29000 embedded, using EBMON a29k-none-none
5191 AMD 29000 embedded with COFF a29k-none-coff
5192 AMD 29000 embedded with a.out a29k-none-aout
5194 testsuite/gdb.hp/gdb.threads-hp/ directory
5196 * REMOVED configurations and files
5198 TI TMS320C80 tic80-*-*
5200 PowerPC Solaris powerpcle-*-solaris*
5201 PowerPC Windows NT powerpcle-*-cygwin32
5202 PowerPC Netware powerpc-*-netware*
5203 Harris/CXUX m88k m88*-harris-cxux*
5204 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5205 ns32k-utek-sysv* ns32k-utek-*
5206 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5207 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5208 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5209 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5210 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5212 * Changes to command line processing
5214 The new `--args' feature can be used to specify command-line arguments
5215 for the inferior from gdb's command line.
5217 * Changes to key bindings
5219 There is a new `operate-and-get-next' function bound to `C-o'.
5221 *** Changes in GDB 5.1.1
5223 Fix compile problem on DJGPP.
5225 Fix a problem with floating-point registers on the i386 being
5228 Fix to stop GDB crashing on .debug_str debug info.
5230 Numerous documentation fixes.
5232 Numerous testsuite fixes.
5234 *** Changes in GDB 5.1:
5236 * New native configurations
5238 Alpha FreeBSD alpha*-*-freebsd*
5239 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5240 MIPS GNU/Linux mips*-*-linux*
5241 MIPS SGI Irix 6.x mips*-sgi-irix6*
5242 ia64 AIX ia64-*-aix*
5243 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5247 Motorola 68HC11 and 68HC12 m68hc11-elf
5249 UltraSparc running GNU/Linux sparc64-*-linux*
5251 * OBSOLETE configurations and files
5253 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5254 Harris/CXUX m88k m88*-harris-cxux*
5255 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5256 ns32k-utek-sysv* ns32k-utek-*
5257 TI TMS320C80 tic80-*-*
5259 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5260 PowerPC Solaris powerpcle-*-solaris*
5261 PowerPC Windows NT powerpcle-*-cygwin32
5262 PowerPC Netware powerpc-*-netware*
5263 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5264 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5265 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5266 Apple Macintosh (MPW) host N/A
5268 stuff.c (Program to stuff files into a specially prepared space in kdb)
5269 kdb-start.c (Main loop for the standalone kernel debugger)
5271 Configurations that have been declared obsolete in this release have
5272 been commented out. Unless there is activity to revive these
5273 configurations, the next release of GDB will have their sources
5274 permanently REMOVED.
5276 * REMOVED configurations and files
5278 Altos 3068 m68*-altos-*
5279 Convex c1-*-*, c2-*-*
5281 ARM RISCix arm-*-* (as host)
5285 * GDB has been converted to ISO C.
5287 GDB's source code has been converted to ISO C. In particular, the
5288 sources are fully protoized, and rely on standard headers being
5293 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5295 * The MI enabled by default.
5297 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5298 revised and enabled by default. Packages which use GDB as a debugging
5299 engine behind a UI or another front end are encouraged to switch to
5300 using the GDB/MI interface, instead of the old annotations interface
5301 which is now deprecated.
5303 * Support for debugging Pascal programs.
5305 GDB now includes support for debugging Pascal programs. The following
5306 main features are supported:
5308 - Pascal-specific data types such as sets;
5310 - automatic recognition of Pascal sources based on file-name
5313 - Pascal-style display of data types, variables, and functions;
5315 - a Pascal expression parser.
5317 However, some important features are not yet supported.
5319 - Pascal string operations are not supported at all;
5321 - there are some problems with boolean types;
5323 - Pascal type hexadecimal constants are not supported
5324 because they conflict with the internal variables format;
5326 - support for Pascal objects and classes is not full yet;
5328 - unlike Pascal, GDB is case-sensitive for symbol names.
5330 * Changes in completion.
5332 Commands such as `shell', `run' and `set args', which pass arguments
5333 to inferior programs, now complete on file names, similar to what
5334 users expect at the shell prompt.
5336 Commands which accept locations, such as `disassemble', `print',
5337 `breakpoint', `until', etc. now complete on filenames as well as
5338 program symbols. Thus, if you type "break foob TAB", and the source
5339 files linked into the programs include `foobar.c', that file name will
5340 be one of the candidates for completion. However, file names are not
5341 considered for completion after you typed a colon that delimits a file
5342 name from a name of a function in that file, as in "break foo.c:bar".
5344 `set demangle-style' completes on available demangling styles.
5346 * New platform-independent commands:
5348 It is now possible to define a post-hook for a command as well as a
5349 hook that runs before the command. For more details, see the
5350 documentation of `hookpost' in the GDB manual.
5352 * Changes in GNU/Linux native debugging.
5354 Support for debugging multi-threaded programs has been completely
5355 revised for all platforms except m68k and sparc. You can now debug as
5356 many threads as your system allows you to have.
5358 Attach/detach is supported for multi-threaded programs.
5360 Support for SSE registers was added for x86. This doesn't work for
5361 multi-threaded programs though.
5363 * Changes in MIPS configurations.
5365 Multi-arch support is enabled for all MIPS configurations.
5367 GDB can now be built as native debugger on SGI Irix 6.x systems for
5368 debugging n32 executables. (Debugging 64-bit executables is not yet
5371 * Unified support for hardware watchpoints in all x86 configurations.
5373 Most (if not all) native x86 configurations support hardware-assisted
5374 breakpoints and watchpoints in a unified manner. This support
5375 implements debug register sharing between watchpoints, which allows to
5376 put a virtually infinite number of watchpoints on the same address,
5377 and also supports watching regions up to 16 bytes with several debug
5380 The new maintenance command `maintenance show-debug-regs' toggles
5381 debugging print-outs in functions that insert, remove, and test
5382 watchpoints and hardware breakpoints.
5384 * Changes in the DJGPP native configuration.
5386 New command ``info dos sysinfo'' displays assorted information about
5387 the CPU, OS, memory, and DPMI server.
5389 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5390 display information about segment descriptors stored in GDT, LDT, and
5393 New commands ``info dos pde'' and ``info dos pte'' display entries
5394 from Page Directory and Page Tables (for now works with CWSDPMI only).
5395 New command ``info dos address-pte'' displays the Page Table entry for
5396 a given linear address.
5398 GDB can now pass command lines longer than 126 characters to the
5399 program being debugged (requires an update to the libdbg.a library
5400 which is part of the DJGPP development kit).
5402 DWARF2 debug info is now supported.
5404 It is now possible to `step' and `next' through calls to `longjmp'.
5406 * Changes in documentation.
5408 All GDB documentation was converted to GFDL, the GNU Free
5409 Documentation License.
5411 Tracepoints-related commands are now fully documented in the GDB
5414 TUI, the Text-mode User Interface, is now documented in the manual.
5416 Tracepoints-related commands are now fully documented in the GDB
5419 The "GDB Internals" manual now has an index. It also includes
5420 documentation of `ui_out' functions, GDB coding standards, x86
5421 hardware watchpoints, and memory region attributes.
5423 * GDB's version number moved to ``version.in''
5425 The Makefile variable VERSION has been replaced by the file
5426 ``version.in''. People creating GDB distributions should update the
5427 contents of this file.
5431 GUD support is now a standard part of the EMACS distribution.
5433 *** Changes in GDB 5.0:
5435 * Improved support for debugging FP programs on x86 targets
5437 Unified and much-improved support for debugging floating-point
5438 programs on all x86 targets. In particular, ``info float'' now
5439 displays the FP registers in the same format on all x86 targets, with
5440 greater level of detail.
5442 * Improvements and bugfixes in hardware-assisted watchpoints
5444 It is now possible to watch array elements, struct members, and
5445 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5446 on x86 targets no longer erroneously trigger when the address is
5449 * Improvements in the native DJGPP version of GDB
5451 The distribution now includes all the scripts and auxiliary files
5452 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5453 machines ``out of the box''.
5455 The DJGPP version can now debug programs that use signals. It is
5456 possible to catch signals that happened in the debuggee, deliver
5457 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5458 would kill the program being debugged.) Programs that hook hardware
5459 interrupts (keyboard, timer, etc.) can also be debugged.
5461 It is now possible to debug DJGPP programs that redirect their
5462 standard handles or switch them to raw (as opposed to cooked) mode, or
5463 even close them. The command ``run < foo > bar'' works as expected,
5464 and ``info terminal'' reports useful information about the debuggee's
5465 terminal, including raw/cooked mode, redirection, etc.
5467 The DJGPP version now uses termios functions for console I/O, which
5468 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5471 DOS-style file names with drive letters are now fully supported by
5474 It is now possible to debug DJGPP programs that switch their working
5475 directory. It is also possible to rerun the debuggee any number of
5476 times without restarting GDB; thus, you can use the same setup,
5477 breakpoints, etc. for many debugging sessions.
5479 * New native configurations
5481 ARM GNU/Linux arm*-*-linux*
5482 PowerPC GNU/Linux powerpc-*-linux*
5486 Motorola MCore mcore-*-*
5487 x86 VxWorks i[3456]86-*-vxworks*
5488 PowerPC VxWorks powerpc-*-vxworks*
5489 TI TMS320C80 tic80-*-*
5491 * OBSOLETE configurations
5493 Altos 3068 m68*-altos-*
5494 Convex c1-*-*, c2-*-*
5496 ARM RISCix arm-*-* (as host)
5499 Configurations that have been declared obsolete will be commented out,
5500 but the code will be left in place. If there is no activity to revive
5501 these configurations before the next release of GDB, the sources will
5502 be permanently REMOVED.
5504 * Gould support removed
5506 Support for the Gould PowerNode and NP1 has been removed.
5508 * New features for SVR4
5510 On SVR4 native platforms (such as Solaris), if you attach to a process
5511 without first loading a symbol file, GDB will now attempt to locate and
5512 load symbols from the running process's executable file.
5514 * Many C++ enhancements
5516 C++ support has been greatly improved. Overload resolution now works properly
5517 in almost all cases. RTTI support is on the way.
5519 * Remote targets can connect to a sub-program
5521 A popen(3) style serial-device has been added. This device starts a
5522 sub-process (such as a stand-alone simulator) and then communicates
5523 with that. The sub-program to run is specified using the syntax
5524 ``|<program> <args>'' vis:
5526 (gdb) set remotedebug 1
5527 (gdb) target extended-remote |mn10300-elf-sim program-args
5529 * MIPS 64 remote protocol
5531 A long standing bug in the mips64 remote protocol where by GDB
5532 expected certain 32 bit registers (ex SR) to be transfered as 32
5533 instead of 64 bits has been fixed.
5535 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5536 added to provide backward compatibility with older versions of GDB.
5538 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5540 The command ``set remotebinarydownload'' command has been replaced by
5541 ``set remote X-packet''. Other commands in ``set remote'' family
5542 include ``set remote P-packet''.
5544 * Breakpoint commands accept ranges.
5546 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5547 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5548 ``tracepoint passcount'' also accepts a range of tracepoints.
5550 * ``apropos'' command added.
5552 The ``apropos'' command searches through command names and
5553 documentation strings, printing out matches, making it much easier to
5554 try to find a command that does what you are looking for.
5558 A new machine oriented interface (MI) has been added to GDB. This
5559 interface is designed for debug environments running GDB as a separate
5560 process. This is part of the long term libGDB project. See the
5561 "GDB/MI" chapter of the GDB manual for further information. It can be
5562 enabled by configuring with:
5564 .../configure --enable-gdbmi
5566 *** Changes in GDB-4.18:
5568 * New native configurations
5570 HP-UX 10.20 hppa*-*-hpux10.20
5571 HP-UX 11.x hppa*-*-hpux11.0*
5572 M68K GNU/Linux m68*-*-linux*
5576 Fujitsu FR30 fr30-*-elf*
5577 Intel StrongARM strongarm-*-*
5578 Mitsubishi D30V d30v-*-*
5580 * OBSOLETE configurations
5582 Gould PowerNode, NP1 np1-*-*, pn-*-*
5584 Configurations that have been declared obsolete will be commented out,
5585 but the code will be left in place. If there is no activity to revive
5586 these configurations before the next release of GDB, the sources will
5587 be permanently REMOVED.
5591 As a compatibility experiment, GDB's source files buildsym.h and
5592 buildsym.c have been converted to pure standard C, no longer
5593 containing any K&R compatibility code. We believe that all systems in
5594 use today either come with a standard C compiler, or have a GCC port
5595 available. If this is not true, please report the affected
5596 configuration to bug-gdb@gnu.org immediately. See the README file for
5597 information about getting a standard C compiler if you don't have one
5602 GDB now uses readline 2.2.
5604 * set extension-language
5606 You can now control the mapping between filename extensions and source
5607 languages by using the `set extension-language' command. For instance,
5608 you can ask GDB to treat .c files as C++ by saying
5609 set extension-language .c c++
5610 The command `info extensions' lists all of the recognized extensions
5611 and their associated languages.
5613 * Setting processor type for PowerPC and RS/6000
5615 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5616 you can use the `set processor' command to specify what variant of the
5617 PowerPC family you are debugging. The command
5621 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5622 following PowerPC and RS6000 variants:
5624 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5625 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5627 403GC IBM PowerPC 403GC
5628 505 Motorola PowerPC 505
5629 860 Motorola PowerPC 860 or 850
5630 601 Motorola PowerPC 601
5631 602 Motorola PowerPC 602
5632 603 Motorola/IBM PowerPC 603 or 603e
5633 604 Motorola PowerPC 604 or 604e
5634 750 Motorola/IBM PowerPC 750 or 750
5636 At the moment, this command just tells GDB what to name the
5637 special-purpose processor registers. Since almost all the affected
5638 registers are inaccessible to user-level programs, this command is
5639 only useful for remote debugging in its present form.
5643 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5644 more extensive support for HP-UX. Added features include shared
5645 library support, kernel threads and hardware watchpoints for 11.00,
5646 support for HP's ANSI C and C++ compilers, and a compatibility mode
5647 for xdb and dbx commands.
5651 HP's donation includes the new concept of catchpoints, which is a
5652 generalization of the old catch command. On HP-UX, it is now possible
5653 to catch exec, fork, and vfork, as well as library loading.
5655 This means that the existing catch command has changed; its first
5656 argument now specifies the type of catch to be set up. See the
5657 output of "help catch" for a list of catchpoint types.
5659 * Debugging across forks
5661 On HP-UX, you can choose which process to debug when a fork() happens
5666 HP has donated a curses-based terminal user interface (TUI). To get
5667 it, build with --enable-tui. Although this can be enabled for any
5668 configuration, at present it only works for native HP debugging.
5670 * GDB remote protocol additions
5672 A new protocol packet 'X' that writes binary data is now available.
5673 Default behavior is to try 'X', then drop back to 'M' if the stub
5674 fails to respond. The settable variable `remotebinarydownload'
5675 allows explicit control over the use of 'X'.
5677 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5678 full 64-bit address. The command
5680 set remoteaddresssize 32
5682 can be used to revert to the old behaviour. For existing remote stubs
5683 the change should not be noticed, as the additional address information
5686 In order to assist in debugging stubs, you may use the maintenance
5687 command `packet' to send any text string to the stub. For instance,
5689 maint packet heythere
5691 sends the packet "$heythere#<checksum>". Note that it is very easy to
5692 disrupt a debugging session by sending the wrong packet at the wrong
5695 The compare-sections command allows you to compare section data on the
5696 target to what is in the executable file without uploading or
5697 downloading, by comparing CRC checksums.
5699 * Tracing can collect general expressions
5701 You may now collect general expressions at tracepoints. This requires
5702 further additions to the target-side stub; see tracepoint.c and
5703 doc/agentexpr.texi for further details.
5705 * mask-address variable for Mips
5707 For Mips targets, you may control the zeroing of the upper 32 bits of
5708 a 64-bit address by entering `set mask-address on'. This is mainly
5709 of interest to users of embedded R4xxx and R5xxx processors.
5711 * Higher serial baud rates
5713 GDB's serial code now allows you to specify baud rates 57600, 115200,
5714 230400, and 460800 baud. (Note that your host system may not be able
5715 to achieve all of these rates.)
5719 The i960 configuration now includes an initial implementation of a
5720 builtin simulator, contributed by Jim Wilson.
5723 *** Changes in GDB-4.17:
5725 * New native configurations
5727 Alpha GNU/Linux alpha*-*-linux*
5728 Unixware 2.x i[3456]86-unixware2*
5729 Irix 6.x mips*-sgi-irix6*
5730 PowerPC GNU/Linux powerpc-*-linux*
5731 PowerPC Solaris powerpcle-*-solaris*
5732 Sparc GNU/Linux sparc-*-linux*
5733 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5737 Argonaut Risc Chip (ARC) arc-*-*
5738 Hitachi H8/300S h8300*-*-*
5739 Matsushita MN10200 w/simulator mn10200-*-*
5740 Matsushita MN10300 w/simulator mn10300-*-*
5741 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5742 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5743 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5744 Mitsubishi D10V w/simulator d10v-*-*
5745 Mitsubishi M32R/D w/simulator m32r-*-elf*
5746 Tsqware Sparclet sparclet-*-*
5747 NEC V850 w/simulator v850-*-*
5749 * New debugging protocols
5751 ARM with RDI protocol arm*-*-*
5752 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5753 DDB and LSI variants of PMON protocol mips*-*-*
5754 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5755 PowerPC with SDS protocol powerpc{,le}-*-eabi
5756 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5760 All configurations can now understand and use the DWARF 2 debugging
5761 format. The choice is automatic, if the symbol file contains DWARF 2
5766 GDB now includes basic Java language support. This support is
5767 only useful with Java compilers that produce native machine code.
5769 * solib-absolute-prefix and solib-search-path
5771 For SunOS and SVR4 shared libraries, you may now set the prefix for
5772 loading absolute shared library symbol files, and the search path for
5773 locating non-absolute shared library symbol files.
5775 * Live range splitting
5777 GDB can now effectively debug code for which GCC has performed live
5778 range splitting as part of its optimization. See gdb/doc/LRS for
5779 more details on the expected format of the stabs information.
5783 GDB's support for the GNU Hurd, including thread debugging, has been
5784 updated to work with current versions of the Hurd.
5788 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5789 instruction set. ARM GDB automatically detects when Thumb
5790 instructions are in use, and adjusts disassembly and backtracing
5795 GDB's MIPS target configurations now handle the MIP16 16-bit
5800 GDB now includes support for overlays; if an executable has been
5801 linked such that multiple sections are based at the same address, GDB
5802 will decide which section to use for symbolic info. You can choose to
5803 control the decision manually, using overlay commands, or implement
5804 additional target-side support and use "overlay load-target" to bring
5805 in the overlay mapping. Do "help overlay" for more detail.
5809 The command "info symbol <address>" displays information about
5810 the symbol at the specified address.
5814 The standard remote protocol now includes an extension that allows
5815 asynchronous collection and display of trace data. This requires
5816 extensive support in the target-side debugging stub. Tracing mode
5817 includes a new interaction mode in GDB and new commands: see the
5818 file tracepoint.c for more details.
5822 Configurations for embedded MIPS now include a simulator contributed
5823 by Cygnus Solutions. The simulator supports the instruction sets
5824 of most MIPS variants.
5828 Sparc configurations may now include the ERC32 simulator contributed
5829 by the European Space Agency. The simulator is not built into
5830 Sparc targets by default; configure with --enable-sim to include it.
5834 For target configurations that may include multiple variants of a
5835 basic architecture (such as MIPS and SH), you may now set the
5836 architecture explicitly. "set arch" sets, "info arch" lists
5837 the possible architectures.
5839 *** Changes in GDB-4.16:
5841 * New native configurations
5843 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5844 M68K NetBSD m68k-*-netbsd*
5845 PowerPC AIX 4.x powerpc-*-aix*
5846 PowerPC MacOS powerpc-*-macos*
5847 PowerPC Windows NT powerpcle-*-cygwin32
5848 RS/6000 AIX 4.x rs6000-*-aix4*
5852 ARM with RDP protocol arm-*-*
5853 I960 with MON960 i960-*-coff
5854 MIPS VxWorks mips*-*-vxworks*
5855 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5856 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5858 Matra Sparclet sparclet-*-*
5862 The powerpc-eabi configuration now includes the PSIM simulator,
5863 contributed by Andrew Cagney, with assistance from Mike Meissner.
5864 PSIM is a very elaborate model of the PowerPC, including not only
5865 basic instruction set execution, but also details of execution unit
5866 performance and I/O hardware. See sim/ppc/README for more details.
5870 GDB now works with Solaris 2.5.
5872 * Windows 95/NT native
5874 GDB will now work as a native debugger on Windows 95 and Windows NT.
5875 To build it from source, you must use the "gnu-win32" environment,
5876 which uses a DLL to emulate enough of Unix to run the GNU tools.
5877 Further information, binaries, and sources are available at
5878 ftp.cygnus.com, under pub/gnu-win32.
5880 * dont-repeat command
5882 If a user-defined command includes the command `dont-repeat', then the
5883 command will not be repeated if the user just types return. This is
5884 useful if the command is time-consuming to run, so that accidental
5885 extra keystrokes don't run the same command many times.
5887 * Send break instead of ^C
5889 The standard remote protocol now includes an option to send a break
5890 rather than a ^C to the target in order to interrupt it. By default,
5891 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5893 * Remote protocol timeout
5895 The standard remote protocol includes a new variable `remotetimeout'
5896 that allows you to set the number of seconds before GDB gives up trying
5897 to read from the target. The default value is 2.
5899 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5901 By default GDB will automatically keep track of objects as they are
5902 loaded and unloaded by the dynamic linker. By using the command `set
5903 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5904 when shared library events occur, thus allowing you to set breakpoints
5905 in shared libraries which are explicitly loaded by the inferior.
5907 Note this feature does not work on hpux8. On hpux9 you must link
5908 /usr/lib/end.o into your program. This feature should work
5909 automatically on hpux10.
5911 * Irix 5.x hardware watchpoint support
5913 Irix 5 configurations now support the use of hardware watchpoints.
5915 * Mips protocol "SYN garbage limit"
5917 When debugging a Mips target using the `target mips' protocol, you
5918 may set the number of characters that GDB will ignore by setting
5919 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5920 every character. The default value is 1050.
5922 * Recording and replaying remote debug sessions
5924 If you set `remotelogfile' to the name of a file, gdb will write to it
5925 a recording of a remote debug session. This recording may then be
5926 replayed back to gdb using "gdbreplay". See gdbserver/README for
5927 details. This is useful when you have a problem with GDB while doing
5928 remote debugging; you can make a recording of the session and send it
5929 to someone else, who can then recreate the problem.
5931 * Speedups for remote debugging
5933 GDB includes speedups for downloading and stepping MIPS systems using
5934 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5935 and more efficient S-record downloading.
5937 * Memory use reductions and statistics collection
5939 GDB now uses less memory and reports statistics about memory usage.
5940 Try the `maint print statistics' command, for example.
5942 *** Changes in GDB-4.15:
5944 * Psymtabs for XCOFF
5946 The symbol reader for AIX GDB now uses partial symbol tables. This
5947 can greatly improve startup time, especially for large executables.
5949 * Remote targets use caching
5951 Remote targets now use a data cache to speed up communication with the
5952 remote side. The data cache could lead to incorrect results because
5953 it doesn't know about volatile variables, thus making it impossible to
5954 debug targets which use memory mapped I/O devices. `set remotecache
5955 off' turns the the data cache off.
5957 * Remote targets may have threads
5959 The standard remote protocol now includes support for multiple threads
5960 in the target system, using new protocol commands 'H' and 'T'. See
5961 gdb/remote.c for details.
5965 If GDB is configured with `--enable-netrom', then it will include
5966 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5967 acts as though it is a bank of ROM on the target board, but you can
5968 write into it over the network. GDB's support consists only of
5969 support for fast loading into the emulated ROM; to debug, you must use
5970 another protocol, such as standard remote protocol. The usual
5971 sequence is something like
5973 target nrom <netrom-hostname>
5975 target remote <netrom-hostname>:1235
5979 GDB now includes support for the Apple Macintosh, as a host only. It
5980 may be run as either an MPW tool or as a standalone application, and
5981 it can debug through the serial port. All the usual GDB commands are
5982 available, but to the target command, you must supply "serial" as the
5983 device type instead of "/dev/ttyXX". See mpw-README in the main
5984 directory for more information on how to build. The MPW configuration
5985 scripts */mpw-config.in support only a few targets, and only the
5986 mips-idt-ecoff target has been tested.
5990 GDB configuration now uses autoconf. This is not user-visible,
5991 but does simplify configuration and building.
5995 GDB now supports hpux10.
5997 *** Changes in GDB-4.14:
5999 * New native configurations
6001 x86 FreeBSD i[345]86-*-freebsd
6002 x86 NetBSD i[345]86-*-netbsd
6003 NS32k NetBSD ns32k-*-netbsd
6004 Sparc NetBSD sparc-*-netbsd
6008 A29K VxWorks a29k-*-vxworks
6009 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6010 CPU32 EST-300 emulator m68*-*-est*
6011 PowerPC ELF powerpc-*-elf
6014 * Alpha OSF/1 support for procfs
6016 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6017 possible to attach to running processes. As the mounting of the /proc
6018 filesystem is optional on the Alpha, GDB automatically determines
6019 the availability of /proc during startup. This can lead to problems
6020 if /proc is unmounted after GDB has been started.
6022 * Arguments to user-defined commands
6024 User commands may accept up to 10 arguments separated by whitespace.
6025 Arguments are accessed within the user command via $arg0..$arg9. A
6028 print $arg0 + $arg1 + $arg2
6030 To execute the command use:
6033 Defines the command "adder" which prints the sum of its three arguments.
6034 Note the arguments are text substitutions, so they may reference variables,
6035 use complex expressions, or even perform inferior function calls.
6037 * New `if' and `while' commands
6039 This makes it possible to write more sophisticated user-defined
6040 commands. Both commands take a single argument, which is the
6041 expression to evaluate, and must be followed by the commands to
6042 execute, one per line, if the expression is nonzero, the list being
6043 terminated by the word `end'. The `if' command list may include an
6044 `else' word, which causes the following commands to be executed only
6045 if the expression is zero.
6047 * Fortran source language mode
6049 GDB now includes partial support for Fortran 77. It will recognize
6050 Fortran programs and can evaluate a subset of Fortran expressions, but
6051 variables and functions may not be handled correctly. GDB will work
6052 with G77, but does not yet know much about symbols emitted by other
6055 * Better HPUX support
6057 Most debugging facilities now work on dynamic executables for HPPAs
6058 running hpux9 or later. You can attach to running dynamically linked
6059 processes, but by default the dynamic libraries will be read-only, so
6060 for instance you won't be able to put breakpoints in them. To change
6061 that behavior do the following before running the program:
6067 This will cause the libraries to be mapped private and read-write.
6068 To revert to the normal behavior, do this:
6074 You cannot set breakpoints or examine data in the library until after
6075 the library is loaded if the function/data symbols do not have
6078 GDB can now also read debug symbols produced by the HP C compiler on
6079 HPPAs (sorry, no C++, Fortran or 68k support).
6081 * Target byte order now dynamically selectable
6083 You can choose which byte order to use with a target system, via the
6084 commands "set endian big" and "set endian little", and you can see the
6085 current setting by using "show endian". You can also give the command
6086 "set endian auto", in which case GDB will use the byte order
6087 associated with the executable. Currently, only embedded MIPS
6088 configurations support dynamic selection of target byte order.
6090 * New DOS host serial code
6092 This version uses DPMI interrupts to handle buffered I/O, so you
6093 no longer need to run asynctsr when debugging boards connected to
6096 *** Changes in GDB-4.13:
6098 * New "complete" command
6100 This lists all the possible completions for the rest of the line, if it
6101 were to be given as a command itself. This is intended for use by emacs.
6103 * Trailing space optional in prompt
6105 "set prompt" no longer adds a space for you after the prompt you set. This
6106 allows you to set a prompt which ends in a space or one that does not.
6108 * Breakpoint hit counts
6110 "info break" now displays a count of the number of times the breakpoint
6111 has been hit. This is especially useful in conjunction with "ignore"; you
6112 can ignore a large number of breakpoint hits, look at the breakpoint info
6113 to see how many times the breakpoint was hit, then run again, ignoring one
6114 less than that number, and this will get you quickly to the last hit of
6117 * Ability to stop printing at NULL character
6119 "set print null-stop" will cause GDB to stop printing the characters of
6120 an array when the first NULL is encountered. This is useful when large
6121 arrays actually contain only short strings.
6123 * Shared library breakpoints
6125 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6126 breakpoints in shared libraries before the executable is run.
6128 * Hardware watchpoints
6130 There is a new hardware breakpoint for the watch command for sparclite
6131 targets. See gdb/sparclite/hw_breakpoint.note.
6133 Hardware watchpoints are also now supported under GNU/Linux.
6137 Annotations have been added. These are for use with graphical interfaces,
6138 and are still experimental. Currently only gdba.el uses these.
6140 * Improved Irix 5 support
6142 GDB now works properly with Irix 5.2.
6144 * Improved HPPA support
6146 GDB now works properly with the latest GCC and GAS.
6148 * New native configurations
6150 Sequent PTX4 i[34]86-sequent-ptx4
6151 HPPA running OSF/1 hppa*-*-osf*
6152 Atari TT running SVR4 m68*-*-sysv4*
6153 RS/6000 LynxOS rs6000-*-lynxos*
6157 OS/9000 i[34]86-*-os9k
6158 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6161 * Hitachi SH7000 and E7000-PC ICE support
6163 There is now support for communicating with the Hitachi E7000-PC ICE.
6164 This is available automatically when GDB is configured for the SH.
6168 As usual, a variety of small fixes and improvements, both generic
6169 and configuration-specific. See the ChangeLog for more detail.
6171 *** Changes in GDB-4.12:
6173 * Irix 5 is now supported
6177 GDB-4.12 on the HPPA has a number of changes which make it unable
6178 to debug the output from the currently released versions of GCC and
6179 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6180 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6181 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6184 *** Changes in GDB-4.11:
6186 * User visible changes:
6190 The "set remotedebug" option is now consistent between the mips remote
6191 target, remote targets using the gdb-specific protocol, UDI (AMD's
6192 debug protocol for the 29k) and the 88k bug monitor. It is now an
6193 integer specifying a debug level (normally 0 or 1, but 2 means more
6194 debugging info for the mips target).
6196 * DEC Alpha native support
6198 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6199 debug info, but GDB works fairly well with the DEC compiler and should
6200 work with a future GCC release. See the README file for a few
6201 Alpha-specific notes.
6203 * Preliminary thread implementation
6205 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6207 * LynxOS native and target support for 386
6209 This release has been hosted on LynxOS 2.2, and also can be configured
6210 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6213 * Improvements in C++ mangling/demangling.
6215 This release has much better g++ debugging, specifically in name
6216 mangling/demangling, virtual function calls, print virtual table,
6217 call methods, ...etc.
6219 *** Changes in GDB-4.10:
6221 * User visible changes:
6223 Remote debugging using the GDB-specific (`target remote') protocol now
6224 supports the `load' command. This is only useful if you have some
6225 other way of getting the stub to the target system, and you can put it
6226 somewhere in memory where it won't get clobbered by the download.
6228 Filename completion now works.
6230 When run under emacs mode, the "info line" command now causes the
6231 arrow to point to the line specified. Also, "info line" prints
6232 addresses in symbolic form (as well as hex).
6234 All vxworks based targets now support a user settable option, called
6235 vxworks-timeout. This option represents the number of seconds gdb
6236 should wait for responses to rpc's. You might want to use this if
6237 your vxworks target is, perhaps, a slow software simulator or happens
6238 to be on the far side of a thin network line.
6242 This release contains support for using a DEC alpha as a GDB host for
6243 cross debugging. Native alpha debugging is not supported yet.
6246 *** Changes in GDB-4.9:
6250 This is the first GDB release which is accompanied by a matching testsuite.
6251 The testsuite requires installation of dejagnu, which should be available
6252 via ftp from most sites that carry GNU software.
6256 'Cfront' style demangling has had its name changed to 'ARM' style, to
6257 emphasize that it was written from the specifications in the C++ Annotated
6258 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6259 disclaimers, it still generated too much confusion with users attempting to
6260 use gdb with AT&T cfront.
6264 GDB now uses a standard remote interface to a simulator library.
6265 So far, the library contains simulators for the Zilog Z8001/2, the
6266 Hitachi H8/300, H8/500 and Super-H.
6268 * New targets supported
6270 H8/300 simulator h8300-hitachi-hms or h8300hms
6271 H8/500 simulator h8500-hitachi-hms or h8500hms
6272 SH simulator sh-hitachi-hms or sh
6273 Z8000 simulator z8k-zilog-none or z8ksim
6274 IDT MIPS board over serial line mips-idt-ecoff
6276 Cross-debugging to GO32 targets is supported. It requires a custom
6277 version of the i386-stub.c module which is integrated with the
6278 GO32 memory extender.
6280 * New remote protocols
6282 MIPS remote debugging protocol.
6284 * New source languages supported
6286 This version includes preliminary support for Chill, a Pascal like language
6287 used by telecommunications companies. Chill support is also being integrated
6288 into the GNU compiler, but we don't know when it will be publically available.
6291 *** Changes in GDB-4.8:
6293 * HP Precision Architecture supported
6295 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6296 version of this support was available as a set of patches from the
6297 University of Utah. GDB does not support debugging of programs
6298 compiled with the HP compiler, because HP will not document their file
6299 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6300 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6302 Many problems in the preliminary version have been fixed.
6304 * Faster and better demangling
6306 We have improved template demangling and fixed numerous bugs in the GNU style
6307 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6308 character types (wchar_t) are now supported. Demangling of each symbol is now
6309 only done once, and is cached when the symbol table for a file is read in.
6310 This results in a small increase in memory usage for C programs, a moderate
6311 increase in memory usage for C++ programs, and a fantastic speedup in
6314 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6315 from the specifications in the Annotated Reference Manual, which AT&T's
6316 compiler does not actually implement.
6318 * G++ multiple inheritance compiler problem
6320 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6321 inheritance lattices was reworked to properly discover ambiguities. We
6322 recently found an example which causes this new algorithm to fail in a
6323 very subtle way, producing bad debug information for those classes.
6324 The file 'gcc.patch' (in this directory) can be applied to gcc to
6325 circumvent the problem. A future GCC release will contain a complete
6328 The previous G++ debug info problem (mentioned below for the gdb-4.7
6329 release) is fixed in gcc version 2.3.2.
6331 * Improved configure script
6333 The `configure' script will now attempt to guess your system type if
6334 you don't supply a host system type. The old scheme of supplying a
6335 host system triplet is preferable over using this. All the magic is
6336 done in the new `config.guess' script. Examine it for details.
6338 We have also brought our configure script much more in line with the FSF's
6339 version. It now supports the --with-xxx options. In particular,
6340 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6341 The resulting GDB will not be able to read arbitrary object file formats --
6342 only the format ``expected'' to be used on the configured target system.
6343 We hope to make this the default in a future release.
6345 * Documentation improvements
6347 There's new internal documentation on how to modify GDB, and how to
6348 produce clean changes to the code. We implore people to read it
6349 before submitting changes.
6351 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6352 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6353 `info' files are also provided. To build `info' files from scratch,
6354 you will need the latest `makeinfo' release, which will be available in
6355 a future texinfo-X.Y release.
6357 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6358 We're not sure exactly which versions have this problem, but it has
6359 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6360 or better. If that isn't possible, there is a patch in
6361 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6362 around this problem.
6366 GDB now supports array constants that can be used in expressions typed in by
6367 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6368 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6371 The new directory `gdb/sparclite' contains a program that demonstrates
6372 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6374 * New native hosts supported
6376 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6377 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6379 * New targets supported
6381 AMD 29k family via UDI a29k-amd-udi or udi29k
6383 * New file formats supported
6385 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6386 HPUX core files, and SCO 3.2v2 core files.
6390 Attaching to processes now works again; thanks for the many bug reports.
6392 We have also stomped on a bunch of core dumps caused by
6393 printf_filtered("%s") problems.
6395 We eliminated a copyright problem on the rpc and ptrace header files
6396 for VxWorks, which was discovered at the last minute during the 4.7
6397 release. You should now be able to build a VxWorks GDB.
6399 You can now interrupt gdb while an attached process is running. This
6400 will cause the attached process to stop, and give control back to GDB.
6402 We fixed problems caused by using too many file descriptors
6403 for reading symbols from object files and libraries. This was
6404 especially a problem for programs that used many (~100) shared
6407 The `step' command now only enters a subroutine if there is line number
6408 information for the subroutine. Otherwise it acts like the `next'
6409 command. Previously, `step' would enter subroutines if there was
6410 any debugging information about the routine. This avoids problems
6411 when using `cc -g1' on MIPS machines.
6413 * Internal improvements
6415 GDB's internal interfaces have been improved to make it easier to support
6416 debugging of multiple languages in the future.
6418 GDB now uses a common structure for symbol information internally.
6419 Minimal symbols (derived from linkage symbols in object files), partial
6420 symbols (from a quick scan of debug information), and full symbols
6421 contain a common subset of information, making it easier to write
6422 shared code that handles any of them.
6424 * New command line options
6426 We now accept --silent as an alias for --quiet.
6430 The memory-mapped-malloc library is now licensed under the GNU Library
6431 General Public License.
6433 *** Changes in GDB-4.7:
6435 * Host/native/target split
6437 GDB has had some major internal surgery to untangle the support for
6438 hosts and remote targets. Now, when you configure GDB for a remote
6439 target, it will no longer load in all of the support for debugging
6440 local programs on the host. When fully completed and tested, this will
6441 ensure that arbitrary host/target combinations are possible.
6443 The primary conceptual shift is to separate the non-portable code in
6444 GDB into three categories. Host specific code is required any time GDB
6445 is compiled on that host, regardless of the target. Target specific
6446 code relates to the peculiarities of the target, but can be compiled on
6447 any host. Native specific code is everything else: it can only be
6448 built when the host and target are the same system. Child process
6449 handling and core file support are two common `native' examples.
6451 GDB's use of /proc for controlling Unix child processes is now cleaner.
6452 It has been split out into a single module under the `target_ops' vector,
6453 plus two native-dependent functions for each system that uses /proc.
6455 * New hosts supported
6457 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6458 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6459 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6461 * New targets supported
6463 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6464 68030 and CPU32 m68030-*-*, m68332-*-*
6466 * New native hosts supported
6468 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6469 (386bsd is not well tested yet)
6470 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6472 * New file formats supported
6474 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6475 supports reading of `a.out.adobe' object files, which are an a.out
6476 format extended with minimal information about multiple sections.
6480 `show copying' is the same as the old `info copying'.
6481 `show warranty' is the same as `info warrantee'.
6482 These were renamed for consistency. The old commands continue to work.
6484 `info handle' is a new alias for `info signals'.
6486 You can now define pre-command hooks, which attach arbitrary command
6487 scripts to any command. The commands in the hook will be executed
6488 prior to the user's command. You can also create a hook which will be
6489 executed whenever the program stops. See gdb.texinfo.
6493 We now deal with Cfront style name mangling, and can even extract type
6494 info from mangled symbols. GDB can automatically figure out which
6495 symbol mangling style your C++ compiler uses.
6497 Calling of methods and virtual functions has been improved as well.
6501 The crash that occured when debugging Sun Ansi-C compiled binaries is
6502 fixed. This was due to mishandling of the extra N_SO stabs output
6505 We also finally got Ultrix 4.2 running in house, and fixed core file
6506 support, with help from a dozen people on the net.
6508 John M. Farrell discovered that the reason that single-stepping was so
6509 slow on all of the Mips based platforms (primarily SGI and DEC) was
6510 that we were trying to demangle and lookup a symbol used for internal
6511 purposes on every instruction that was being stepped through. Changing
6512 the name of that symbol so that it couldn't be mistaken for a C++
6513 mangled symbol sped things up a great deal.
6515 Rich Pixley sped up symbol lookups in general by getting much smarter
6516 about when C++ symbol mangling is necessary. This should make symbol
6517 completion (TAB on the command line) much faster. It's not as fast as
6518 we'd like, but it's significantly faster than gdb-4.6.
6522 A new user controllable variable 'call_scratch_address' can
6523 specify the location of a scratch area to be used when GDB
6524 calls a function in the target. This is necessary because the
6525 usual method of putting the scratch area on the stack does not work
6526 in systems that have separate instruction and data spaces.
6528 We integrated changes to support the 29k UDI (Universal Debugger
6529 Interface), but discovered at the last minute that we didn't have all
6530 of the appropriate copyright paperwork. We are working with AMD to
6531 resolve this, and hope to have it available soon.
6535 We have sped up the remote serial line protocol, especially for targets
6536 with lots of registers. It now supports a new `expedited status' ('T')
6537 message which can be used in place of the existing 'S' status message.
6538 This allows the remote stub to send only the registers that GDB
6539 needs to make a quick decision about single-stepping or conditional
6540 breakpoints, eliminating the need to fetch the entire register set for
6541 each instruction being stepped through.
6543 The GDB remote serial protocol now implements a write-through cache for
6544 registers, only re-reading the registers if the target has run.
6546 There is also a new remote serial stub for SPARC processors. You can
6547 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6548 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6549 processor with a serial port.
6553 Configure.in files have become much easier to read and modify. A new
6554 `table driven' format makes it more obvious what configurations are
6555 supported, and what files each one uses.
6559 There is a new opcodes library which will eventually contain all of the
6560 disassembly routines and opcode tables. At present, it only contains
6561 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6562 disassembler (binutils/objdump) to share these routines.
6564 The libiberty library is now copylefted under the GNU Library General
6565 Public License. This allows more liberal use, and was done so libg++
6566 can use it. This makes no difference to GDB, since the Library License
6567 grants all the rights from the General Public License.
6571 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6572 reference to the stabs symbol info used by the debugger. It is (as far
6573 as we know) the only published document on this fascinating topic. We
6574 encourage you to read it, compare it to the stabs information on your
6575 system, and send improvements on the document in general (to
6576 bug-gdb@prep.ai.mit.edu).
6578 And, of course, many bugs have been fixed.
6581 *** Changes in GDB-4.6:
6583 * Better support for C++ function names
6585 GDB now accepts as input the "demangled form" of C++ overloaded function
6586 names and member function names, and can do command completion on such names
6587 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6588 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6589 Make use of command completion, it is your friend.
6591 GDB also now accepts a variety of C++ mangled symbol formats. They are
6592 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6593 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6594 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6595 for the list of formats.
6597 * G++ symbol mangling problem
6599 Recent versions of gcc have a bug in how they emit debugging information for
6600 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6601 directory) can be applied to gcc to fix the problem. Alternatively, if you
6602 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6603 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6604 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6607 * New 'maintenance' command
6609 All of the commands related to hacking GDB internals have been moved out of
6610 the main command set, and now live behind the 'maintenance' command. This
6611 can also be abbreviated as 'mt'. The following changes were made:
6613 dump-me -> maintenance dump-me
6614 info all-breakpoints -> maintenance info breakpoints
6615 printmsyms -> maintenance print msyms
6616 printobjfiles -> maintenance print objfiles
6617 printpsyms -> maintenance print psymbols
6618 printsyms -> maintenance print symbols
6620 The following commands are new:
6622 maintenance demangle Call internal GDB demangler routine to
6623 demangle a C++ link name and prints the result.
6624 maintenance print type Print a type chain for a given symbol
6626 * Change to .gdbinit file processing
6628 We now read the $HOME/.gdbinit file before processing the argv arguments
6629 (e.g. reading symbol files or core files). This allows global parameters to
6630 be set, which will apply during the symbol reading. The ./.gdbinit is still
6631 read after argv processing.
6633 * New hosts supported
6635 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6637 GNU/Linux support i386-unknown-linux or linux
6639 We are also including code to support the HP/PA running BSD and HPUX. This
6640 is almost guaranteed not to work, as we didn't have time to test or build it
6641 for this release. We are including it so that the more adventurous (or
6642 masochistic) of you can play with it. We also had major problems with the
6643 fact that the compiler that we got from HP doesn't support the -g option.
6646 * New targets supported
6648 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6650 * More smarts about finding #include files
6652 GDB now remembers the compilation directory for all include files, and for
6653 all files from which C is generated (like yacc and lex sources). This
6654 greatly improves GDB's ability to find yacc/lex sources, and include files,
6655 especially if you are debugging your program from a directory different from
6656 the one that contains your sources.
6658 We also fixed a bug which caused difficulty with listing and setting
6659 breakpoints in include files which contain C code. (In the past, you had to
6660 try twice in order to list an include file that you hadn't looked at before.)
6662 * Interesting infernals change
6664 GDB now deals with arbitrary numbers of sections, where the symbols for each
6665 section must be relocated relative to that section's landing place in the
6666 target's address space. This work was needed to support ELF with embedded
6667 stabs used by Solaris-2.0.
6669 * Bug fixes (of course!)
6671 There have been loads of fixes for the following things:
6672 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6673 i960, stabs, DOS(GO32), procfs, etc...
6675 See the ChangeLog for details.
6677 *** Changes in GDB-4.5:
6679 * New machines supported (host and target)
6681 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6683 SGI Irix-4.x mips-sgi-irix4 or iris4
6685 * New malloc package
6687 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6688 Mmalloc is capable of handling mutiple heaps of memory. It is also
6689 capable of saving a heap to a file, and then mapping it back in later.
6690 This can be used to greatly speedup the startup of GDB by using a
6691 pre-parsed symbol table which lives in a mmalloc managed heap. For
6692 more details, please read mmalloc/mmalloc.texi.
6696 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6697 'help info proc' for details.
6699 * MIPS ecoff symbol table format
6701 The code that reads MIPS symbol table format is now supported on all hosts.
6702 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6705 * File name changes for MS-DOS
6707 Many files in the config directories have been renamed to make it easier to
6708 support GDB on MS-DOSe systems (which have very restrictive file name
6709 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6710 environment) is close to working but has some remaining problems. Note
6711 that debugging of DOS programs is not supported, due to limitations
6712 in the ``operating system'', but it can be used to host cross-debugging.
6714 * Cross byte order fixes
6716 Many fixes have been made to support cross debugging of Sparc and MIPS
6717 targets from hosts whose byte order differs.
6719 * New -mapped and -readnow options
6721 If memory-mapped files are available on your system through the 'mmap'
6722 system call, you can use the -mapped option on the `file' or
6723 `symbol-file' commands to cause GDB to write the symbols from your
6724 program into a reusable file. If the program you are debugging is
6725 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6726 Future GDB debugging sessions will notice the presence of this file,
6727 and will quickly map in symbol information from it, rather than reading
6728 the symbol table from the executable program. Using the '-mapped'
6729 option in a GDB `file' or `symbol-file' command has the same effect as
6730 starting GDB with the '-mapped' command-line option.
6732 You can cause GDB to read the entire symbol table immediately by using
6733 the '-readnow' option with any of the commands that load symbol table
6734 information (or on the GDB command line). This makes the command
6735 slower, but makes future operations faster.
6737 The -mapped and -readnow options are typically combined in order to
6738 build a `fred.syms' file that contains complete symbol information.
6739 A simple GDB invocation to do nothing but build a `.syms' file for future
6742 gdb -batch -nx -mapped -readnow programname
6744 The `.syms' file is specific to the host machine on which GDB is run.
6745 It holds an exact image of GDB's internal symbol table. It cannot be
6746 shared across multiple host platforms.
6748 * longjmp() handling
6750 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6751 siglongjmp() without losing control. This feature has not yet been ported to
6752 all systems. It currently works on many 386 platforms, all MIPS-based
6753 platforms (SGI, DECstation, etc), and Sun3/4.
6757 Preliminary work has been put in to support the new Solaris OS from Sun. At
6758 this time, it can control and debug processes, but it is not capable of
6763 As always, many many bug fixes. The major areas were with g++, and mipsread.
6764 People using the MIPS-based platforms should experience fewer mysterious
6765 crashes and trashed symbol tables.
6767 *** Changes in GDB-4.4:
6769 * New machines supported (host and target)
6771 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6773 BSD Reno on Vax vax-dec-bsd
6774 Ultrix on Vax vax-dec-ultrix
6776 * New machines supported (target)
6778 AMD 29000 embedded, using EBMON a29k-none-none
6782 GDB continues to improve its handling of C++. `References' work better.
6783 The demangler has also been improved, and now deals with symbols mangled as
6784 per the Annotated C++ Reference Guide.
6786 GDB also now handles `stabs' symbol information embedded in MIPS
6787 `ecoff' symbol tables. Since the ecoff format was not easily
6788 extensible to handle new languages such as C++, this appeared to be a
6789 good way to put C++ debugging info into MIPS binaries. This option
6790 will be supported in the GNU C compiler, version 2, when it is
6793 * New features for SVR4
6795 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6796 shared libraries. Debugging dynamically linked programs should present
6797 only minor differences from debugging statically linked programs.
6799 The `info proc' command will print out information about any process
6800 on an SVR4 system (including the one you are debugging). At the moment,
6801 it prints the address mappings of the process.
6803 If you bring up GDB on another SVR4 system, please send mail to
6804 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6806 * Better dynamic linking support in SunOS
6808 Reading symbols from shared libraries which contain debugging symbols
6809 now works properly. However, there remain issues such as automatic
6810 skipping of `transfer vector' code during function calls, which
6811 make it harder to debug code in a shared library, than to debug the
6812 same code linked statically.
6816 GDB is now using the latest `getopt' routines from the FSF. This
6817 version accepts the -- prefix for options with long names. GDB will
6818 continue to accept the old forms (-option and +option) as well.
6819 Various single letter abbreviations for options have been explicity
6820 added to the option table so that they won't get overshadowed in the
6821 future by other options that begin with the same letter.
6825 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6826 Many assorted bugs have been handled. Many more remain to be handled.
6827 See the various ChangeLog files (primarily in gdb and bfd) for details.
6830 *** Changes in GDB-4.3:
6832 * New machines supported (host and target)
6834 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6835 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6836 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6838 * Almost SCO Unix support
6840 We had hoped to support:
6841 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6842 (except for core file support), but we discovered very late in the release
6843 that it has problems with process groups that render gdb unusable. Sorry
6844 about that. I encourage people to fix it and post the fixes.
6846 * Preliminary ELF and DWARF support
6848 GDB can read ELF object files on System V Release 4, and can handle
6849 debugging records for C, in DWARF format, in ELF files. This support
6850 is preliminary. If you bring up GDB on another SVR4 system, please
6851 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6856 GDB now uses the latest `readline' library. One user-visible change
6857 is that two tabs will list possible command completions, which previously
6858 required typing M-? (meta-question mark, or ESC ?).
6862 The `stepi' bug that many of you noticed has been squashed.
6863 Many bugs in C++ have been handled. Many more remain to be handled.
6864 See the various ChangeLog files (primarily in gdb and bfd) for details.
6866 * State of the MIPS world (in case you wondered):
6868 GDB can understand the symbol tables emitted by the compilers
6869 supplied by most vendors of MIPS-based machines, including DEC. These
6870 symbol tables are in a format that essentially nobody else uses.
6872 Some versions of gcc come with an assembler post-processor called
6873 mips-tfile. This program is required if you want to do source-level
6874 debugging of gcc-compiled programs. I believe FSF does not ship
6875 mips-tfile with gcc version 1, but it will eventually come with gcc
6878 Debugging of g++ output remains a problem. g++ version 1.xx does not
6879 really support it at all. (If you're lucky, you should be able to get
6880 line numbers and stack traces to work, but no parameters or local
6881 variables.) With some work it should be possible to improve the
6884 When gcc version 2 is released, you will have somewhat better luck.
6885 However, even then you will get confusing results for inheritance and
6888 We will eventually provide full debugging of g++ output on
6889 DECstations. This will probably involve some kind of stabs-in-ecoff
6890 encapulation, but the details have not been worked out yet.
6893 *** Changes in GDB-4.2:
6895 * Improved configuration
6897 Only one copy of `configure' exists now, and it is not self-modifying.
6898 Porting BFD is simpler.
6902 The `step' and `next' commands now only stop at the first instruction
6903 of a source line. This prevents the multiple stops that used to occur
6904 in switch statements, for-loops, etc. `Step' continues to stop if a
6905 function that has debugging information is called within the line.
6909 Lots of small bugs fixed. More remain.
6911 * New host supported (not target)
6913 Intel 386 PC clone running Mach i386-none-mach
6916 *** Changes in GDB-4.1:
6918 * Multiple source language support
6920 GDB now has internal scaffolding to handle several source languages.
6921 It determines the type of each source file from its filename extension,
6922 and will switch expression parsing and number formatting to match the
6923 language of the function in the currently selected stack frame.
6924 You can also specifically set the language to be used, with
6925 `set language c' or `set language modula-2'.
6929 GDB now has preliminary support for the GNU Modula-2 compiler,
6930 currently under development at the State University of New York at
6931 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6932 continue through the fall of 1991 and into 1992.
6934 Other Modula-2 compilers are currently not supported, and attempting to
6935 debug programs compiled with them will likely result in an error as the
6936 symbol table is read. Feel free to work on it, though!
6938 There are hooks in GDB for strict type checking and range checking,
6939 in the `Modula-2 philosophy', but they do not currently work.
6943 GDB can now write to executable and core files (e.g. patch
6944 a variable's value). You must turn this switch on, specify
6945 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6946 by assigning a new value to a variable. Modifications take
6949 * Automatic SunOS shared library reading
6951 When you run your program, GDB automatically determines where its
6952 shared libraries (if any) have been loaded, and reads their symbols.
6953 The `share' command is no longer needed. This also works when
6954 examining core files.
6958 You can specify the number of lines that the `list' command shows.
6961 * New machines supported (host and target)
6963 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6964 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6965 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6967 * New hosts supported (not targets)
6969 IBM RT/PC: romp-ibm-aix or rtpc
6971 * New targets supported (not hosts)
6973 AMD 29000 embedded with COFF a29k-none-coff
6974 AMD 29000 embedded with a.out a29k-none-aout
6975 Ultracomputer remote kernel debug a29k-nyu-kern
6977 * New remote interfaces
6983 *** Changes in GDB-4.0:
6987 Wide output is wrapped at good places to make the output more readable.
6989 Gdb now supports cross-debugging from a host machine of one type to a
6990 target machine of another type. Communication with the target system
6991 is over serial lines. The ``target'' command handles connecting to the
6992 remote system; the ``load'' command will download a program into the
6993 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6994 also supports debugging of realtime processes running under VxWorks,
6995 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6996 stub on the target system.
6998 New CPUs supported include the AMD 29000 and Intel 960.
7000 GDB now reads object files and symbol tables via a ``binary file''
7001 library, which allows a single copy of GDB to debug programs of multiple
7002 object file types such as a.out and coff.
7004 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7005 refcard.dvi and refcard.ps are available to format it).
7008 * Control-Variable user interface simplified
7010 All variables that control the operation of the debugger can be set
7011 by the ``set'' command, and displayed by the ``show'' command.
7013 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7014 ``Show prompt'' produces the response:
7015 Gdb's prompt is new-gdb=>.
7017 What follows are the NEW set commands. The command ``help set'' will
7018 print a complete list of old and new set commands. ``help set FOO''
7019 will give a longer description of the variable FOO. ``show'' will show
7020 all of the variable descriptions and their current settings.
7022 confirm on/off: Enables warning questions for operations that are
7023 hard to recover from, e.g. rerunning the program while
7024 it is already running. Default is ON.
7026 editing on/off: Enables EMACS style command line editing
7027 of input. Previous lines can be recalled with
7028 control-P, the current line can be edited with control-B,
7029 you can search for commands with control-R, etc.
7032 history filename NAME: NAME is where the gdb command history
7033 will be stored. The default is .gdb_history,
7034 or the value of the environment variable
7037 history size N: The size, in commands, of the command history. The
7038 default is 256, or the value of the environment variable
7041 history save on/off: If this value is set to ON, the history file will
7042 be saved after exiting gdb. If set to OFF, the
7043 file will not be saved. The default is OFF.
7045 history expansion on/off: If this value is set to ON, then csh-like
7046 history expansion will be performed on
7047 command line input. The default is OFF.
7049 radix N: Sets the default radix for input and output. It can be set
7050 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7051 in the current radix, so "set radix 10" is always a no-op.
7053 height N: This integer value is the number of lines on a page. Default
7054 is 24, the current `stty rows'' setting, or the ``li#''
7055 setting from the termcap entry matching the environment
7058 width N: This integer value is the number of characters on a line.
7059 Default is 80, the current `stty cols'' setting, or the ``co#''
7060 setting from the termcap entry matching the environment
7063 Note: ``set screensize'' is obsolete. Use ``set height'' and
7064 ``set width'' instead.
7066 print address on/off: Print memory addresses in various command displays,
7067 such as stack traces and structure values. Gdb looks
7068 more ``symbolic'' if you turn this off; it looks more
7069 ``machine level'' with it on. Default is ON.
7071 print array on/off: Prettyprint arrays. New convenient format! Default
7074 print demangle on/off: Print C++ symbols in "source" form if on,
7077 print asm-demangle on/off: Same, for assembler level printouts
7080 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7083 * Support for Epoch Environment.
7085 The epoch environment is a version of Emacs v18 with windowing. One
7086 new command, ``inspect'', is identical to ``print'', except that if you
7087 are running in the epoch environment, the value is printed in its own
7091 * Support for Shared Libraries
7093 GDB can now debug programs and core files that use SunOS shared libraries.
7094 Symbols from a shared library cannot be referenced
7095 before the shared library has been linked with the program (this
7096 happens after you type ``run'' and before the function main() is entered).
7097 At any time after this linking (including when examining core files
7098 from dynamically linked programs), gdb reads the symbols from each
7099 shared library when you type the ``sharedlibrary'' command.
7100 It can be abbreviated ``share''.
7102 sharedlibrary REGEXP: Load shared object library symbols for files
7103 matching a unix regular expression. No argument
7104 indicates to load symbols for all shared libraries.
7106 info sharedlibrary: Status of loaded shared libraries.
7111 A watchpoint stops execution of a program whenever the value of an
7112 expression changes. Checking for this slows down execution
7113 tremendously whenever you are in the scope of the expression, but is
7114 quite useful for catching tough ``bit-spreader'' or pointer misuse
7115 problems. Some machines such as the 386 have hardware for doing this
7116 more quickly, and future versions of gdb will use this hardware.
7118 watch EXP: Set a watchpoint (breakpoint) for an expression.
7120 info watchpoints: Information about your watchpoints.
7122 delete N: Deletes watchpoint number N (same as breakpoints).
7123 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7124 enable N: Re-enables watchpoint number N (same as breakpoints).
7127 * C++ multiple inheritance
7129 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7132 * C++ exception handling
7134 Gdb now supports limited C++ exception handling. Besides the existing
7135 ability to breakpoint on an exception handler, gdb can breakpoint on
7136 the raising of an exception (before the stack is peeled back to the
7139 catch FOO: If there is a FOO exception handler in the dynamic scope,
7140 set a breakpoint to catch exceptions which may be raised there.
7141 Multiple exceptions (``catch foo bar baz'') may be caught.
7143 info catch: Lists all exceptions which may be caught in the
7144 current stack frame.
7147 * Minor command changes
7149 The command ``call func (arg, arg, ...)'' now acts like the print
7150 command, except it does not print or save a value if the function's result
7151 is void. This is similar to dbx usage.
7153 The ``up'' and ``down'' commands now always print the frame they end up
7154 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7155 frames without printing.
7157 * New directory command
7159 'dir' now adds directories to the FRONT of the source search path.
7160 The path starts off empty. Source files that contain debug information
7161 about the directory in which they were compiled can be found even
7162 with an empty path; Sun CC and GCC include this information. If GDB can't
7163 find your source file in the current directory, type "dir .".
7165 * Configuring GDB for compilation
7167 For normal use, type ``./configure host''. See README or gdb.texinfo
7170 GDB now handles cross debugging. If you are remotely debugging between
7171 two different machines, type ``./configure host -target=targ''.
7172 Host is the machine where GDB will run; targ is the machine
7173 where the program that you are debugging will run.