1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * New built-in convenience variables $_gdb_major and $_gdb_minor
7 provide the GDB version. They are handy for conditionally using
8 features available only in or since specific GDB versions, in
9 scripts that should work error-free with many different versions,
10 such as in system-wide init files.
12 * GDB now supports Thread Local Storage (TLS) variables on several
13 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
14 architectures require kernel changes. TLS is not yet supported for
15 amd64 and i386 process core dumps.
17 * Support for Pointer Authentication on AArch64 Linux.
19 * Two new convenience functions $_cimag and $_creal that extract the
20 imaginary and real parts respectively from complex numbers.
24 ** The gdb.Value type has a new method 'format_string' which returns a
25 string representing the value. The formatting is controlled by the
26 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
27 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
28 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
30 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
31 provide the exitcode or exit status of the shell commands launched by
32 GDB commands such as "shell", "pipe" and "make".
36 | [COMMAND] | SHELL_COMMAND
37 | -d DELIM COMMAND DELIM SHELL_COMMAND
38 pipe [COMMAND] | SHELL_COMMAND
39 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
40 Executes COMMAND and sends its output to SHELL_COMMAND.
41 With no COMMAND, repeat the last executed command
42 and send its output to SHELL_COMMAND.
44 set may-call-functions [on|off]
45 show may-call-functions
46 This controls whether GDB will attempt to call functions in
47 the program, such as with expressions in the print command. It
48 defaults to on. Calling functions in the program being debugged
49 can have undesired side effects. It is now possible to forbid
50 such function calls. If function calls are forbidden, GDB will throw
51 an error when a command (such as print expression) calls a function
54 set print finish [on|off]
56 This controls whether the `finish' command will display the value
57 that is returned by the current function. When `off', the value is
58 still entered into the value history, but it is not printed. The
63 Allows deeply nested structures to be simplified when printing by
64 replacing deeply nested parts (beyond the max-depth) with ellipses.
65 The default max-depth is 20, but this can be set to unlimited to get
66 the old behavior back.
68 set logging debugredirect [on|off]
69 By default, GDB debug output will go to both the terminal and the logfile.
70 Set if you want debug output to go only to the log file.
75 This lists all the possible completions for the rest of the line, if it
76 were to be given as a command itself. This is intended for use by MI
77 frontends in cases when separate CLI and MI channels cannot be used.
81 The testsuite now creates the files gdb.cmd (containing the arguments
82 used to launch GDB) and gdb.in (containing all the commands sent to
83 GDB) in the output directory for each test script. Multiple invocations
84 are appended with .1, .2, .3 etc.
86 *** Changes in GDB 8.3
88 * GDB and GDBserver now support access to additional registers on
89 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
92 * GDB now has experimental support for the compilation and injection of
93 C++ source code into the inferior. This beta release does not include
94 support for several language features, such as templates, constructors,
97 This feature requires GCC 7.1 or higher built with libcp1.so
100 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
101 can be passed using the '[ADDRESS]:PORT' notation, or the regular
102 'ADDRESS:PORT' method.
104 * DWARF index cache: GDB can now automatically save indices of DWARF
105 symbols on disk to speed up further loading of the same binaries.
107 * Ada task switching is now supported on aarch64-elf targets when
108 debugging a program using the Ravenscar Profile. For more information,
109 see the "Tasking Support when using the Ravenscar Profile" section
110 in the GDB user manual.
112 * GDB in batch mode now exits with status 1 if the last command to be
115 * The RISC-V target now supports target descriptions.
117 * System call catchpoints now support system call aliases on FreeBSD.
118 When the ABI of a system call changes in FreeBSD, this is
119 implemented by leaving a compatibility system call using the old ABI
120 at the existing number and allocating a new system call number for
121 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
122 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
123 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
124 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
125 so that a system call catchpoint for the 'kevent' system call will
126 catch invocations of both the 'kevent' and 'freebsd11_kevent'
127 binaries. This ensures that 'kevent' system calls are caught for
128 binaries using either the old or new ABIs.
130 * Terminal styling is now available for the CLI and the TUI. GNU
131 Source Highlight can additionally be used to provide styling of
132 source code snippets. See the "set style" commands, below, for more
135 * Removed support for old demangling styles arm, edg, gnu, hp and
140 set debug compile-cplus-types
141 show debug compile-cplus-types
142 Control the display of debug output about type conversion in the
143 C++ compile feature. Commands have no effect while compiliong
148 Control whether debug output about files/functions skipping is
151 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
152 Apply a command to some frames.
153 FLAG arguments allow to control what output to produce and how to handle
154 errors raised when applying COMMAND to a frame.
157 Apply a command to all threads (ignoring errors and empty output).
158 Shortcut for 'thread apply all -s COMMAND'.
161 Apply a command to all frames (ignoring errors and empty output).
162 Shortcut for 'frame apply all -s COMMAND'.
165 Apply a command to all frames of all threads (ignoring errors and empty
167 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
169 maint set dwarf unwinders (on|off)
170 maint show dwarf unwinders
171 Control whether DWARF unwinders can be used.
174 Display a list of open files for a process.
178 Changes to the "frame", "select-frame", and "info frame" CLI commands.
179 These commands all now take a frame specification which
180 is either a frame level, or one of the keywords 'level', 'address',
181 'function', or 'view' followed by a parameter. Selecting a frame by
182 address, or viewing a frame outside the current backtrace now
183 requires the use of a keyword. Selecting a frame by level is
184 unchanged. The MI comment "-stack-select-frame" is unchanged.
186 target remote FILENAME
187 target extended-remote FILENAME
188 If FILENAME is a Unix domain socket, GDB will attempt to connect
189 to this socket instead of opening FILENAME as a character device.
191 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
192 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
193 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
194 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
195 These commands can now print only the searched entities
196 matching the provided regexp(s), giving a condition
197 on the entity names or entity types. The flag -q disables
198 printing headers or informations messages.
204 These commands now determine the syntax for the shown entities
205 according to the language chosen by `set language'. In particular,
206 `set language auto' means to automatically choose the language of
209 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
210 The 'thread apply' command accepts new FLAG arguments.
211 FLAG arguments allow to control what output to produce and how to handle
212 errors raised when applying COMMAND to a thread.
214 set tui tab-width NCHARS
215 show tui tab-width NCHARS
216 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
218 set style enabled [on|off]
220 Enable or disable terminal styling. Styling is enabled by default
221 on most hosts, but disabled by default when in batch mode.
223 set style sources [on|off]
225 Enable or disable source code styling. Source code styling is
226 enabled by default, but only takes effect if styling in general is
227 enabled, and if GDB was linked with GNU Source Highlight.
229 set style filename foreground COLOR
230 set style filename background COLOR
231 set style filename intensity VALUE
232 Control the styling of file names.
234 set style function foreground COLOR
235 set style function background COLOR
236 set style function intensity VALUE
237 Control the styling of function names.
239 set style variable foreground COLOR
240 set style variable background COLOR
241 set style variable intensity VALUE
242 Control the styling of variable names.
244 set style address foreground COLOR
245 set style address background COLOR
246 set style address intensity VALUE
247 Control the styling of addresses.
251 ** The default version of the MI interpreter is now 3 (-i=mi3).
253 ** The '-data-disassemble' MI command now accepts an '-a' option to
254 disassemble the whole function surrounding the given program
255 counter value or function name. Support for this feature can be
256 verified by using the "-list-features" command, which should
257 contain "data-disassemble-a-option".
259 ** Command responses and notifications that include a frame now include
260 the frame's architecture in a new "arch" attribute.
262 ** The output of information about multi-location breakpoints (which is
263 syntactically incorrect in MI 2) has changed in MI 3. This affects
264 the following commands and events:
268 - =breakpoint-created
269 - =breakpoint-modified
271 The -fix-multi-location-breakpoint-output command can be used to enable
272 this behavior with previous MI versions.
274 * New native configurations
276 GNU/Linux/RISC-V riscv*-*-linux*
277 FreeBSD/riscv riscv*-*-freebsd*
281 GNU/Linux/RISC-V riscv*-*-linux*
283 CSKY GNU/LINUX csky*-*-linux
284 FreeBSD/riscv riscv*-*-freebsd*
286 GNU/Linux/OpenRISC or1k*-*-linux*
290 GDB no longer supports native debugging on versions of MS-Windows
295 ** GDB no longer supports Python versions less than 2.6.
297 ** The gdb.Inferior type has a new 'progspace' property, which is the program
298 space associated to that inferior.
300 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
301 of objfiles associated to that program space.
303 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
304 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
307 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
308 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
309 correct and did not work properly.
311 ** The gdb.Value type has a new constructor, which is used to construct a
312 gdb.Value from a Python buffer object and a gdb.Type.
318 Enable or disable the undefined behavior sanitizer. This is
319 disabled by default, but passing --enable-ubsan=yes or
320 --enable-ubsan=auto to configure will enable it. Enabling this can
321 cause a performance penalty. The undefined behavior sanitizer was
322 first introduced in GCC 4.9.
324 *** Changes in GDB 8.2
326 * The 'set disassembler-options' command now supports specifying options
329 * The 'symbol-file' command now accepts an '-o' option to add a relative
330 offset to all sections.
332 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
333 a relative offset to all sections, but it allows to override the load
334 address of individual sections using '-s'.
336 * The 'add-symbol-file' command no longer requires the second argument
337 (address of the text section).
339 * The endianness used with the 'set endian auto' mode in the absence of
340 an executable selected for debugging is now the last endianness chosen
341 either by one of the 'set endian big' and 'set endian little' commands
342 or by inferring from the last executable used, rather than the startup
345 * The pager now allows a "c" response, meaning to disable the pager
346 for the rest of the current command.
348 * The commands 'info variables/functions/types' now show the source line
349 numbers of symbol definitions when available.
351 * 'info proc' now works on running processes on FreeBSD systems and core
352 files created on FreeBSD systems.
354 * C expressions can now use _Alignof, and C++ expressions can now use
357 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
358 the vector length while the process is running.
364 Control display of debugging info regarding the FreeBSD native target.
366 set|show varsize-limit
367 This new setting allows the user to control the maximum size of Ada
368 objects being printed when those objects have a variable type,
369 instead of that maximum size being hardcoded to 65536 bytes.
371 set|show record btrace cpu
372 Controls the processor to be used for enabling errata workarounds for
375 maint check libthread-db
376 Run integrity checks on the current inferior's thread debugging
379 maint set check-libthread-db (on|off)
380 maint show check-libthread-db
381 Control whether to run integrity checks on inferior specific thread
382 debugging libraries as they are loaded. The default is not to
387 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
389 ** The commands attached to a breakpoint can be set by assigning to
390 the breakpoint's "commands" field.
392 ** gdb.execute can now execute multi-line gdb commands.
394 ** The new functions gdb.convenience_variable and
395 gdb.set_convenience_variable can be used to get and set the value
396 of convenience variables.
398 ** A gdb.Parameter will no longer print the "set" help text on an
399 ordinary "set"; instead by default a "set" will be silent unless
400 the get_set_string method returns a non-empty string.
404 RiscV ELF riscv*-*-elf
406 * Removed targets and native configurations
408 m88k running OpenBSD m88*-*-openbsd*
409 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
410 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
411 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
413 * Aarch64/Linux hardware watchpoints improvements
415 Hardware watchpoints on unaligned addresses are now properly
416 supported when running Linux kernel 4.10 or higher: read and access
417 watchpoints are no longer spuriously missed, and all watchpoints
418 lengths between 1 and 8 bytes are supported. On older kernels,
419 watchpoints set on unaligned addresses are no longer missed, with
420 the tradeoff that there is a possibility of false hits being
425 --enable-codesign=CERT
426 This can be used to invoke "codesign -s CERT" after building gdb.
427 This option is useful on macOS, where code signing is required for
428 gdb to work properly.
430 --disable-gdbcli has been removed
431 This is now silently accepted, but does nothing.
433 *** Changes in GDB 8.1
435 * GDB now supports dynamically creating arbitrary register groups specified
436 in XML target descriptions. This allows for finer grain grouping of
437 registers on systems with a large amount of registers.
439 * The 'ptype' command now accepts a '/o' flag, which prints the
440 offsets and sizes of fields in a struct, like the pahole(1) tool.
442 * New "--readnever" command line option instructs GDB to not read each
443 symbol file's symbolic debug information. This makes startup faster
444 but at the expense of not being able to perform symbolic debugging.
445 This option is intended for use cases where symbolic debugging will
446 not be used, e.g., when you only need to dump the debuggee's core.
448 * GDB now uses the GNU MPFR library, if available, to emulate target
449 floating-point arithmetic during expression evaluation when the target
450 uses different floating-point formats than the host. At least version
451 3.1 of GNU MPFR is required.
453 * GDB now supports access to the guarded-storage-control registers and the
454 software-based guarded-storage broadcast control registers on IBM z14.
456 * On Unix systems, GDB now supports transmitting environment variables
457 that are to be set or unset to GDBserver. These variables will
458 affect the environment to be passed to the remote inferior.
460 To inform GDB of environment variables that are to be transmitted to
461 GDBserver, use the "set environment" command. Only user set
462 environment variables are sent to GDBserver.
464 To inform GDB of environment variables that are to be unset before
465 the remote inferior is started by the GDBserver, use the "unset
466 environment" command.
468 * Completion improvements
470 ** GDB can now complete function parameters in linespecs and
471 explicit locations without quoting. When setting breakpoints,
472 quoting around functions names to help with TAB-completion is
473 generally no longer necessary. For example, this now completes
476 (gdb) b function(in[TAB]
477 (gdb) b function(int)
479 Related, GDB is no longer confused with completing functions in
480 C++ anonymous namespaces:
483 (gdb) b (anonymous namespace)::[TAB][TAB]
484 (anonymous namespace)::a_function()
485 (anonymous namespace)::b_function()
487 ** GDB now has much improved linespec and explicit locations TAB
488 completion support, that better understands what you're
489 completing and offers better suggestions. For example, GDB no
490 longer offers data symbols as possible completions when you're
491 setting a breakpoint.
493 ** GDB now TAB-completes label symbol names.
495 ** The "complete" command now mimics TAB completion accurately.
497 * New command line options (gcore)
500 Dump all memory mappings.
502 * Breakpoints on C++ functions are now set on all scopes by default
504 By default, breakpoints on functions/methods are now interpreted as
505 specifying all functions with the given name ignoring missing
506 leading scopes (namespaces and classes).
508 For example, assuming a C++ program with symbols named:
513 both commands "break func()" and "break B::func()" set a breakpoint
516 You can use the new flag "-qualified" to override this. This makes
517 GDB interpret the specified function name as a complete
518 fully-qualified name instead. For example, using the same C++
519 program, the "break -q B::func" command sets a breakpoint on
520 "B::func", only. A parameter has been added to the Python
521 gdb.Breakpoint constructor to achieve the same result when creating
522 a breakpoint from Python.
524 * Breakpoints on functions marked with C++ ABI tags
526 GDB can now set breakpoints on functions marked with C++ ABI tags
527 (e.g., [abi:cxx11]). See here for a description of ABI tags:
528 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
530 Functions with a C++11 abi tag are demangled/displayed like this:
532 function[abi:cxx11](int)
535 You can now set a breakpoint on such functions simply as if they had
538 (gdb) b function(int)
540 Or if you need to disambiguate between tags, like:
542 (gdb) b function[abi:other_tag](int)
544 Tab completion was adjusted accordingly as well.
548 ** New events gdb.new_inferior, gdb.inferior_deleted, and
549 gdb.new_thread are emitted. See the manual for further
550 description of these.
552 ** A new function, "gdb.rbreak" has been added to the Python API.
553 This function allows the setting of a large number of breakpoints
554 via a regex pattern in Python. See the manual for further details.
556 ** Python breakpoints can now accept explicit locations. See the
557 manual for a further description of this feature.
560 * New features in the GDB remote stub, GDBserver
562 ** GDBserver is now able to start inferior processes with a
563 specified initial working directory.
565 The user can set the desired working directory to be used from
566 GDB using the new "set cwd" command.
568 ** New "--selftest" command line option runs some GDBserver self
569 tests. These self tests are disabled in releases.
571 ** On Unix systems, GDBserver now does globbing expansion and variable
572 substitution in inferior command line arguments.
574 This is done by starting inferiors using a shell, like GDB does.
575 See "set startup-with-shell" in the user manual for how to disable
576 this from GDB when using "target extended-remote". When using
577 "target remote", you can disable the startup with shell by using the
578 new "--no-startup-with-shell" GDBserver command line option.
580 ** On Unix systems, GDBserver now supports receiving environment
581 variables that are to be set or unset from GDB. These variables
582 will affect the environment to be passed to the inferior.
584 * When catching an Ada exception raised with a message, GDB now prints
585 the message in the catchpoint hit notification. In GDB/MI mode, that
586 information is provided as an extra field named "exception-message"
587 in the *stopped notification.
589 * Trait objects can now be inspected When debugging Rust code. This
590 requires compiler support which will appear in Rust 1.24.
594 QEnvironmentHexEncoded
595 Inform GDBserver of an environment variable that is to be passed to
596 the inferior when starting it.
599 Inform GDBserver of an environment variable that is to be unset
600 before starting the remote inferior.
603 Inform GDBserver that the environment should be reset (i.e.,
604 user-set environment variables should be unset).
607 Indicates whether the inferior must be started with a shell or not.
610 Tell GDBserver that the inferior to be started should use a specific
613 * The "maintenance print c-tdesc" command now takes an optional
614 argument which is the file name of XML target description.
616 * The "maintenance selftest" command now takes an optional argument to
617 filter the tests to be run.
619 * The "enable", and "disable" commands now accept a range of
620 breakpoint locations, e.g. "enable 1.3-5".
625 Set and show the current working directory for the inferior.
628 Set and show compilation command used for compiling and injecting code
629 with the 'compile' commands.
631 set debug separate-debug-file
632 show debug separate-debug-file
633 Control the display of debug output about separate debug file search.
635 set dump-excluded-mappings
636 show dump-excluded-mappings
637 Control whether mappings marked with the VM_DONTDUMP flag should be
638 dumped when generating a core file.
641 List the registered selftests.
644 Start the debugged program stopping at the first instruction.
647 Control display of debugging messages related to OpenRISC targets.
649 set|show print type nested-type-limit
650 Set and show the limit of nesting level for nested types that the
651 type printer will show.
653 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
656 * Safer/improved support for debugging with no debug info
658 GDB no longer assumes functions with no debug information return
661 This means that GDB now refuses to call such functions unless you
662 tell it the function's type, by either casting the call to the
663 declared return type, or by casting the function to a function
664 pointer of the right type, and calling that:
666 (gdb) p getenv ("PATH")
667 'getenv' has unknown return type; cast the call to its declared return type
668 (gdb) p (char *) getenv ("PATH")
669 $1 = 0x7fffffffe "/usr/local/bin:/"...
670 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
671 $2 = 0x7fffffffe "/usr/local/bin:/"...
673 Similarly, GDB no longer assumes that global variables with no debug
674 info have type 'int', and refuses to print the variable's value
675 unless you tell it the variable's type:
678 'var' has unknown type; cast it to its declared type
682 * New native configurations
684 FreeBSD/aarch64 aarch64*-*-freebsd*
685 FreeBSD/arm arm*-*-freebsd*
689 FreeBSD/aarch64 aarch64*-*-freebsd*
690 FreeBSD/arm arm*-*-freebsd*
691 OpenRISC ELF or1k*-*-elf
693 * Removed targets and native configurations
695 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
697 *** Changes in GDB 8.0
699 * GDB now supports access to the PKU register on GNU/Linux. The register is
700 added by the Memory Protection Keys for Userspace feature which will be
701 available in future Intel CPUs.
703 * GDB now supports C++11 rvalue references.
707 ** New functions to start, stop and access a running btrace recording.
708 ** Rvalue references are now supported in gdb.Type.
710 * GDB now supports recording and replaying rdrand and rdseed Intel 64
713 * Building GDB and GDBserver now requires a C++11 compiler.
715 For example, GCC 4.8 or later.
717 It is no longer possible to build GDB or GDBserver with a C
718 compiler. The --disable-build-with-cxx configure option has been
721 * Building GDB and GDBserver now requires GNU make >= 3.81.
723 It is no longer supported to build GDB or GDBserver with another
724 implementation of the make program or an earlier version of GNU make.
726 * Native debugging on MS-Windows supports command-line redirection
728 Command-line arguments used for starting programs on MS-Windows can
729 now include redirection symbols supported by native Windows shells,
730 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
731 as "run", "start", and "set args", as well as the corresponding MI
734 * Support for thread names on MS-Windows.
736 GDB now catches and handles the special exception that programs
737 running on MS-Windows use to assign names to threads in the
740 * Support for Java programs compiled with gcj has been removed.
742 * User commands now accept an unlimited number of arguments.
743 Previously, only up to 10 was accepted.
745 * The "eval" command now expands user-defined command arguments.
747 This makes it easier to process a variable number of arguments:
752 eval "print $arg%d", $i
757 * Target descriptions can now describe registers for sparc32 and sparc64.
759 * GDB now supports DWARF version 5 (debug information format).
760 Its .debug_names index is not yet supported.
762 * New native configurations
764 FreeBSD/mips mips*-*-freebsd
768 Synopsys ARC arc*-*-elf32
769 FreeBSD/mips mips*-*-freebsd
771 * Removed targets and native configurations
773 Alpha running FreeBSD alpha*-*-freebsd*
774 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
779 Erases all the flash memory regions reported by the target.
781 maint print arc arc-instruction address
782 Print internal disassembler information about instruction at a given address.
786 set disassembler-options
787 show disassembler-options
788 Controls the passing of target specific information to the disassembler.
789 If it is necessary to specify more than one disassembler option then
790 multiple options can be placed together into a comma separated list.
791 The default value is the empty string. Currently, the only supported
792 targets are ARM, PowerPC and S/390.
797 Erases all the flash memory regions reported by the target. This is
798 equivalent to the CLI command flash-erase.
800 -file-list-shared-libraries
801 List the shared libraries in the program. This is
802 equivalent to the CLI command "info shared".
805 Catchpoints stopping the program when Ada exceptions are
806 handled. This is equivalent to the CLI command "catch handlers".
808 *** Changes in GDB 7.12
810 * GDB and GDBserver now build with a C++ compiler by default.
812 The --enable-build-with-cxx configure option is now enabled by
813 default. One must now explicitly configure with
814 --disable-build-with-cxx in order to build with a C compiler. This
815 option will be removed in a future release.
817 * GDBserver now supports recording btrace without maintaining an active
820 * GDB now supports a negative repeat count in the 'x' command to examine
821 memory backward from the given address. For example:
824 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
825 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
826 (gdb) x/-5i 0x0000000000400580
827 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
828 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
829 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
830 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
831 0x40057b <main(int, char**)+25>:
832 callq 0x400536 <Func1(int, char const*)>
834 * Fortran: Support structures with fields of dynamic types and
835 arrays of dynamic types.
837 * The symbol dumping maintenance commands have new syntax.
838 maint print symbols [-pc address] [--] [filename]
839 maint print symbols [-objfile objfile] [-source source] [--] [filename]
840 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
841 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
842 maint print msymbols [-objfile objfile] [--] [filename]
844 * GDB now supports multibit bitfields and enums in target register
847 * New Python-based convenience function $_as_string(val), which returns
848 the textual representation of a value. This function is especially
849 useful to obtain the text label of an enum value.
851 * Intel MPX bound violation handling.
853 Segmentation faults caused by a Intel MPX boundary violation
854 now display the kind of violation (upper or lower), the memory
855 address accessed and the memory bounds, along with the usual
856 signal received and code location.
860 Program received signal SIGSEGV, Segmentation fault
861 Upper bound violation while accessing address 0x7fffffffc3b3
862 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
863 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
865 * Rust language support.
866 GDB now supports debugging programs written in the Rust programming
867 language. See https://www.rust-lang.org/ for more information about
870 * Support for running interpreters on specified input/output devices
872 GDB now supports a new mechanism that allows frontends to provide
873 fully featured GDB console views, as a better alternative to
874 building such views on top of the "-interpreter-exec console"
875 command. See the new "new-ui" command below. With that command,
876 frontends can now start GDB in the traditional command-line mode
877 running in an embedded terminal emulator widget, and create a
878 separate MI interpreter running on a specified i/o device. In this
879 way, GDB handles line editing, history, tab completion, etc. in the
880 console all by itself, and the GUI uses the separate MI interpreter
881 for its own control and synchronization, invisible to the command
884 * The "catch syscall" command catches groups of related syscalls.
886 The "catch syscall" command now supports catching a group of related
887 syscalls using the 'group:' or 'g:' prefix.
892 skip -gfile file-glob-pattern
893 skip -function function
894 skip -rfunction regular-expression
895 A generalized form of the skip command, with new support for
896 glob-style file names and regular expressions for function names.
897 Additionally, a file spec and a function spec may now be combined.
899 maint info line-table REGEXP
900 Display the contents of GDB's internal line table data struture.
903 Run any GDB unit tests that were compiled in.
906 Start a new user interface instance running INTERP as interpreter,
907 using the TTY file for input/output.
911 ** gdb.Breakpoint objects have a new attribute "pending", which
912 indicates whether the breakpoint is pending.
913 ** Three new breakpoint-related events have been added:
914 gdb.breakpoint_created, gdb.breakpoint_modified, and
915 gdb.breakpoint_deleted.
918 Signal ("set") the given MS-Windows event object. This is used in
919 conjunction with the Windows JIT debugging (AeDebug) support, where
920 the OS suspends a crashing process until a debugger can attach to
921 it. Resuming the crashing process, in order to debug it, is done by
924 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
925 was added in GDBserver, including JIT compiling fast tracepoint's
926 conditional expression bytecode into native code.
928 * Support for various remote target protocols and ROM monitors has
931 target m32rsdi Remote M32R debugging over SDI
932 target mips MIPS remote debugging protocol
933 target pmon PMON ROM monitor
934 target ddb NEC's DDB variant of PMON for Vr4300
935 target rockhopper NEC RockHopper variant of PMON
936 target lsi LSI variant of PMO
938 * Support for tracepoints and fast tracepoints on powerpc-linux,
939 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
940 including JIT compiling fast tracepoint's conditional expression
941 bytecode into native code.
943 * MI async record =record-started now includes the method and format used for
944 recording. For example:
946 =record-started,thread-group="i1",method="btrace",format="bts"
948 * MI async record =thread-selected now includes the frame field. For example:
950 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
954 Andes NDS32 nds32*-*-elf
956 *** Changes in GDB 7.11
958 * GDB now supports debugging kernel-based threads on FreeBSD.
960 * Per-inferior thread numbers
962 Thread numbers are now per inferior instead of global. If you're
963 debugging multiple inferiors, GDB displays thread IDs using a
964 qualified INF_NUM.THR_NUM form. For example:
968 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
969 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
970 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
971 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
973 As consequence, thread numbers as visible in the $_thread
974 convenience variable and in Python's InferiorThread.num attribute
975 are no longer unique between inferiors.
977 GDB now maintains a second thread ID per thread, referred to as the
978 global thread ID, which is the new equivalent of thread numbers in
979 previous releases. See also $_gthread below.
981 For backwards compatibility, MI's thread IDs always refer to global
984 * Commands that accept thread IDs now accept the qualified
985 INF_NUM.THR_NUM form as well. For example:
988 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
991 * In commands that accept a list of thread IDs, you can now refer to
992 all threads of an inferior using a star wildcard. GDB accepts
993 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
994 refer to all threads of the current inferior. For example, "info
997 * You can use "info threads -gid" to display the global thread ID of
1000 * The new convenience variable $_gthread holds the global number of
1003 * The new convenience variable $_inferior holds the number of the
1006 * GDB now displays the ID and name of the thread that hit a breakpoint
1007 or received a signal, if your program is multi-threaded. For
1010 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1011 Thread 1 "main" received signal SIGINT, Interrupt.
1013 * Record btrace now supports non-stop mode.
1015 * Support for tracepoints on aarch64-linux was added in GDBserver.
1017 * The 'record instruction-history' command now indicates speculative execution
1018 when using the Intel Processor Trace recording format.
1020 * GDB now allows users to specify explicit locations, bypassing
1021 the linespec parser. This feature is also available to GDB/MI
1024 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1025 GDB now is able to debug both AArch64 applications and ARM applications
1028 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1029 including JIT compiling fast tracepoint's conditional expression bytecode
1032 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1034 * "info threads", "info inferiors", "info display", "info checkpoints"
1035 and "maint info program-spaces" now list the corresponding items in
1036 ascending ID order, for consistency with all other "info" commands.
1038 * In Ada, the overloads selection menu has been enhanced to display the
1039 parameter types and the return types for the matching overloaded subprograms.
1043 maint set target-non-stop (on|off|auto)
1044 maint show target-non-stop
1045 Control whether GDB targets always operate in non-stop mode even if
1046 "set non-stop" is "off". The default is "auto", meaning non-stop
1047 mode is enabled if supported by the target.
1049 maint set bfd-sharing
1050 maint show bfd-sharing
1051 Control the reuse of bfd objects.
1054 show debug bfd-cache
1055 Control display of debugging info regarding bfd caching.
1059 Control display of debugging info regarding FreeBSD threads.
1061 set remote multiprocess-extensions-packet
1062 show remote multiprocess-extensions-packet
1063 Set/show the use of the remote protocol multiprocess extensions.
1065 set remote thread-events
1066 show remote thread-events
1067 Set/show the use of thread create/exit events.
1069 set ada print-signatures on|off
1070 show ada print-signatures"
1071 Control whether parameter types and return types are displayed in overloads
1072 selection menus. It is activaled (@code{on}) by default.
1076 Controls the maximum size of memory, in bytes, that GDB will
1077 allocate for value contents. Prevents incorrect programs from
1078 causing GDB to allocate overly large buffers. Default is 64k.
1080 * The "disassemble" command accepts a new modifier: /s.
1081 It prints mixed source+disassembly like /m with two differences:
1082 - disassembled instructions are now printed in program order, and
1083 - and source for all relevant files is now printed.
1084 The "/m" option is now considered deprecated: its "source-centric"
1085 output hasn't proved useful in practice.
1087 * The "record instruction-history" command accepts a new modifier: /s.
1088 It behaves exactly like /m and prints mixed source+disassembly.
1090 * The "set scheduler-locking" command supports a new mode "replay".
1091 It behaves like "off" in record mode and like "on" in replay mode.
1093 * Support for various ROM monitors has been removed:
1095 target dbug dBUG ROM monitor for Motorola ColdFire
1096 target picobug Motorola picobug monitor
1097 target dink32 DINK32 ROM monitor for PowerPC
1098 target m32r Renesas M32R/D ROM monitor
1099 target mon2000 mon2000 ROM monitor
1100 target ppcbug PPCBUG ROM monitor for PowerPC
1102 * Support for reading/writing memory and extracting values on architectures
1103 whose memory is addressable in units of any integral multiple of 8 bits.
1106 Allows to break when an Ada exception is handled.
1108 * New remote packets
1111 Indicates that an exec system call was executed.
1113 exec-events feature in qSupported
1114 The qSupported packet allows GDB to request support for exec
1115 events using the new 'gdbfeature' exec-event, and the qSupported
1116 response can contain the corresponding 'stubfeature'. Set and
1117 show commands can be used to display whether these features are enabled.
1120 Equivalent to interrupting with the ^C character, but works in
1123 thread created stop reason (T05 create:...)
1124 Indicates that the thread was just created and is stopped at entry.
1126 thread exit stop reply (w exitcode;tid)
1127 Indicates that the thread has terminated.
1130 Enables/disables thread create and exit event reporting. For
1131 example, this is used in non-stop mode when GDB stops a set of
1132 threads and synchronously waits for the their corresponding stop
1133 replies. Without exit events, if one of the threads exits, GDB
1134 would hang forever not knowing that it should no longer expect a
1135 stop for that same thread.
1138 Indicates that there are no resumed threads left in the target (all
1139 threads are stopped). The remote stub reports support for this stop
1140 reply to GDB's qSupported query.
1143 Enables/disables catching syscalls from the inferior process.
1144 The remote stub reports support for this packet to GDB's qSupported query.
1146 syscall_entry stop reason
1147 Indicates that a syscall was just called.
1149 syscall_return stop reason
1150 Indicates that a syscall just returned.
1152 * Extended-remote exec events
1154 ** GDB now has support for exec events on extended-remote Linux targets.
1155 For such targets with Linux kernels 2.5.46 and later, this enables
1156 follow-exec-mode and exec catchpoints.
1158 set remote exec-event-feature-packet
1159 show remote exec-event-feature-packet
1160 Set/show the use of the remote exec event feature.
1162 * Thread names in remote protocol
1164 The reply to qXfer:threads:read may now include a name attribute for each
1167 * Target remote mode fork and exec events
1169 ** GDB now has support for fork and exec events on target remote mode
1170 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1171 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1172 fork and exec catchpoints.
1174 * Remote syscall events
1176 ** GDB now has support for catch syscall on remote Linux targets,
1177 currently enabled on x86/x86_64 architectures.
1179 set remote catch-syscall-packet
1180 show remote catch-syscall-packet
1181 Set/show the use of the remote catch syscall feature.
1185 ** The -var-set-format command now accepts the zero-hexadecimal
1186 format. It outputs data in hexadecimal format with zero-padding on the
1191 ** gdb.InferiorThread objects have a new attribute "global_num",
1192 which refers to the thread's global thread ID. The existing
1193 "num" attribute now refers to the thread's per-inferior number.
1194 See "Per-inferior thread numbers" above.
1195 ** gdb.InferiorThread objects have a new attribute "inferior", which
1196 is the Inferior object the thread belongs to.
1198 *** Changes in GDB 7.10
1200 * Support for process record-replay and reverse debugging on aarch64*-linux*
1201 targets has been added. GDB now supports recording of A64 instruction set
1202 including advance SIMD instructions.
1204 * Support for Sun's version of the "stabs" debug file format has been removed.
1206 * GDB now honors the content of the file /proc/PID/coredump_filter
1207 (PID is the process ID) on GNU/Linux systems. This file can be used
1208 to specify the types of memory mappings that will be included in a
1209 corefile. For more information, please refer to the manual page of
1210 "core(5)". GDB also has a new command: "set use-coredump-filter
1211 on|off". It allows to set whether GDB will read the content of the
1212 /proc/PID/coredump_filter file when generating a corefile.
1214 * The "info os" command on GNU/Linux can now display information on
1216 "info os cpus" Listing of all cpus/cores on the system
1218 * GDB has two new commands: "set serial parity odd|even|none" and
1219 "show serial parity". These allows to set or show parity for the
1222 * The "info source" command now displays the producer string if it was
1223 present in the debug info. This typically includes the compiler version
1224 and may include things like its command line arguments.
1226 * The "info dll", an alias of the "info sharedlibrary" command,
1227 is now available on all platforms.
1229 * Directory names supplied to the "set sysroot" commands may be
1230 prefixed with "target:" to tell GDB to access shared libraries from
1231 the target system, be it local or remote. This replaces the prefix
1232 "remote:". The default sysroot has been changed from "" to
1233 "target:". "remote:" is automatically converted to "target:" for
1234 backward compatibility.
1236 * The system root specified by "set sysroot" will be prepended to the
1237 filename of the main executable (if reported to GDB as absolute by
1238 the operating system) when starting processes remotely, and when
1239 attaching to already-running local or remote processes.
1241 * GDB now supports automatic location and retrieval of executable
1242 files from remote targets. Remote debugging can now be initiated
1243 using only a "target remote" or "target extended-remote" command
1244 (no "set sysroot" or "file" commands are required). See "New remote
1247 * The "dump" command now supports verilog hex format.
1249 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1251 * On GNU/Linux, GDB and gdbserver are now able to access executable
1252 and shared library files without a "set sysroot" command when
1253 attaching to processes running in different mount namespaces from
1254 the debugger. This makes it possible to attach to processes in
1255 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1256 See "New remote packets" below.
1258 * The "tui reg" command now provides completion for all of the
1259 available register groups, including target specific groups.
1261 * The HISTSIZE environment variable is no longer read when determining
1262 the size of GDB's command history. GDB now instead reads the dedicated
1263 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1264 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1269 ** Memory ports can now be unbuffered.
1273 ** gdb.Objfile objects have a new attribute "username",
1274 which is the name of the objfile as specified by the user,
1275 without, for example, resolving symlinks.
1276 ** You can now write frame unwinders in Python.
1277 ** gdb.Type objects have a new method "optimized_out",
1278 returning optimized out gdb.Value instance of this type.
1279 ** gdb.Value objects have new methods "reference_value" and
1280 "const_value" which return a reference to the value and a
1281 "const" version of the value respectively.
1285 maint print symbol-cache
1286 Print the contents of the symbol cache.
1288 maint print symbol-cache-statistics
1289 Print statistics of symbol cache usage.
1291 maint flush-symbol-cache
1292 Flush the contents of the symbol cache.
1296 Start branch trace recording using Branch Trace Store (BTS) format.
1299 Evaluate expression by using the compiler and print result.
1303 Explicit commands for enabling and disabling tui mode.
1306 set mpx bound on i386 and amd64
1307 Support for bound table investigation on Intel MPX enabled applications.
1311 Start branch trace recording using Intel Processor Trace format.
1314 Print information about branch tracing internals.
1316 maint btrace packet-history
1317 Print the raw branch tracing data.
1319 maint btrace clear-packet-history
1320 Discard the stored raw branch tracing data.
1323 Discard all branch tracing data. It will be fetched and processed
1324 anew by the next "record" command.
1329 Renamed from "set debug dwarf2-die".
1330 show debug dwarf-die
1331 Renamed from "show debug dwarf2-die".
1333 set debug dwarf-read
1334 Renamed from "set debug dwarf2-read".
1335 show debug dwarf-read
1336 Renamed from "show debug dwarf2-read".
1338 maint set dwarf always-disassemble
1339 Renamed from "maint set dwarf2 always-disassemble".
1340 maint show dwarf always-disassemble
1341 Renamed from "maint show dwarf2 always-disassemble".
1343 maint set dwarf max-cache-age
1344 Renamed from "maint set dwarf2 max-cache-age".
1345 maint show dwarf max-cache-age
1346 Renamed from "maint show dwarf2 max-cache-age".
1348 set debug dwarf-line
1349 show debug dwarf-line
1350 Control display of debugging info regarding DWARF line processing.
1353 show max-completions
1354 Set the maximum number of candidates to be considered during
1355 completion. The default value is 200. This limit allows GDB
1356 to avoid generating large completion lists, the computation of
1357 which can cause the debugger to become temporarily unresponsive.
1359 set history remove-duplicates
1360 show history remove-duplicates
1361 Control the removal of duplicate history entries.
1363 maint set symbol-cache-size
1364 maint show symbol-cache-size
1365 Control the size of the symbol cache.
1367 set|show record btrace bts buffer-size
1368 Set and show the size of the ring buffer used for branch tracing in
1370 The obtained size may differ from the requested size. Use "info
1371 record" to see the obtained buffer size.
1373 set debug linux-namespaces
1374 show debug linux-namespaces
1375 Control display of debugging info regarding Linux namespaces.
1377 set|show record btrace pt buffer-size
1378 Set and show the size of the ring buffer used for branch tracing in
1379 Intel Processor Trace format.
1380 The obtained size may differ from the requested size. Use "info
1381 record" to see the obtained buffer size.
1383 maint set|show btrace pt skip-pad
1384 Set and show whether PAD packets are skipped when computing the
1387 * The command 'thread apply all' can now support new option '-ascending'
1388 to call its specified command for all threads in ascending order.
1390 * Python/Guile scripting
1392 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1393 special section named `.debug_gdb_scripts'.
1395 * New remote packets
1397 qXfer:btrace-conf:read
1398 Return the branch trace configuration for the current thread.
1400 Qbtrace-conf:bts:size
1401 Set the requested ring buffer size for branch tracing in BTS format.
1404 Enable Intel Procesor Trace-based branch tracing for the current
1405 process. The remote stub reports support for this packet to GDB's
1408 Qbtrace-conf:pt:size
1409 Set the requested ring buffer size for branch tracing in Intel Processor
1413 Indicates a memory breakpoint instruction was executed, irrespective
1414 of whether it was GDB that planted the breakpoint or the breakpoint
1415 is hardcoded in the program. This is required for correct non-stop
1419 Indicates the target stopped for a hardware breakpoint. This is
1420 required for correct non-stop mode operation.
1423 Return information about files on the remote system.
1425 qXfer:exec-file:read
1426 Return the full absolute name of the file that was executed to
1427 create a process running on the remote system.
1430 Select the filesystem on which vFile: operations with filename
1431 arguments will operate. This is required for GDB to be able to
1432 access files on remote targets where the remote stub does not
1433 share a common filesystem with the inferior(s).
1436 Indicates that a fork system call was executed.
1439 Indicates that a vfork system call was executed.
1441 vforkdone stop reason
1442 Indicates that a vfork child of the specified process has executed
1443 an exec or exit, allowing the vfork parent to resume execution.
1445 fork-events and vfork-events features in qSupported
1446 The qSupported packet allows GDB to request support for fork and
1447 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1448 and the qSupported response can contain the corresponding
1449 'stubfeatures'. Set and show commands can be used to display
1450 whether these features are enabled.
1452 * Extended-remote fork events
1454 ** GDB now has support for fork events on extended-remote Linux
1455 targets. For targets with Linux kernels 2.5.60 and later, this
1456 enables follow-fork-mode and detach-on-fork for both fork and
1457 vfork, as well as fork and vfork catchpoints.
1459 * The info record command now shows the recording format and the
1460 branch tracing configuration for the current thread when using
1461 the btrace record target.
1462 For the BTS format, it shows the ring buffer size.
1464 * GDB now has support for DTrace USDT (Userland Static Defined
1465 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1467 * GDB now supports access to vector registers on S/390 GNU/Linux
1470 * Removed command line options
1472 -xdb HP-UX XDB compatibility mode.
1474 * Removed targets and native configurations
1476 HP/PA running HP-UX hppa*-*-hpux*
1477 Itanium running HP-UX ia64-*-hpux*
1479 * New configure options
1482 This configure option allows the user to build GDB with support for
1483 Intel Processor Trace (default: auto). This requires libipt.
1485 --with-libipt-prefix=PATH
1486 Specify the path to the version of libipt that GDB should use.
1487 $PATH/include should contain the intel-pt.h header and
1488 $PATH/lib should contain the libipt.so library.
1490 *** Changes in GDB 7.9.1
1494 ** Xmethods can now specify a result type.
1496 *** Changes in GDB 7.9
1498 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1502 ** You can now access frame registers from Python scripts.
1503 ** New attribute 'producer' for gdb.Symtab objects.
1504 ** gdb.Objfile objects have a new attribute "progspace",
1505 which is the gdb.Progspace object of the containing program space.
1506 ** gdb.Objfile objects have a new attribute "owner".
1507 ** gdb.Objfile objects have a new attribute "build_id",
1508 which is the build ID generated when the file was built.
1509 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1510 ** A new event "gdb.clear_objfiles" has been added, triggered when
1511 selecting a new file to debug.
1512 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1513 ** New function gdb.lookup_objfile.
1515 New events which are triggered when GDB modifies the state of the
1518 ** gdb.events.inferior_call_pre: Function call is about to be made.
1519 ** gdb.events.inferior_call_post: Function call has just been made.
1520 ** gdb.events.memory_changed: A memory location has been altered.
1521 ** gdb.events.register_changed: A register has been altered.
1523 * New Python-based convenience functions:
1525 ** $_caller_is(name [, number_of_frames])
1526 ** $_caller_matches(regexp [, number_of_frames])
1527 ** $_any_caller_is(name [, number_of_frames])
1528 ** $_any_caller_matches(regexp [, number_of_frames])
1530 * GDB now supports the compilation and injection of source code into
1531 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1532 to compile the source code to object code, and if successful, inject
1533 and execute that code within the current context of the inferior.
1534 Currently the C language is supported. The commands used to
1535 interface with this new feature are:
1537 compile code [-raw|-r] [--] [source code]
1538 compile file [-raw|-r] filename
1542 demangle [-l language] [--] name
1543 Demangle "name" in the specified language, or the current language
1544 if elided. This command is renamed from the "maint demangle" command.
1545 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1546 as "maint demangler-warning".
1548 queue-signal signal-name-or-number
1549 Queue a signal to be delivered to the thread when it is resumed.
1551 add-auto-load-scripts-directory directory
1552 Add entries to the list of directories from which to load auto-loaded
1555 maint print user-registers
1556 List all currently available "user" registers.
1558 compile code [-r|-raw] [--] [source code]
1559 Compile, inject, and execute in the inferior the executable object
1560 code produced by compiling the provided source code.
1562 compile file [-r|-raw] filename
1563 Compile and inject into the inferior the executable object code
1564 produced by compiling the source code stored in the filename
1567 * On resume, GDB now always passes the signal the program had stopped
1568 for to the thread the signal was sent to, even if the user changed
1569 threads before resuming. Previously GDB would often (but not
1570 always) deliver the signal to the thread that happens to be current
1573 * Conversely, the "signal" command now consistently delivers the
1574 requested signal to the current thread. GDB now asks for
1575 confirmation if the program had stopped for a signal and the user
1576 switched threads meanwhile.
1578 * "breakpoint always-inserted" modes "off" and "auto" merged.
1580 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1581 won't remove breakpoints from the target until all threads stop,
1582 even in non-stop mode. The "auto" mode has been removed, and "off"
1583 is now the default mode.
1587 set debug symbol-lookup
1588 show debug symbol-lookup
1589 Control display of debugging info regarding symbol lookup.
1593 ** The -list-thread-groups command outputs an exit-code field for
1594 inferiors that have exited.
1598 MIPS SDE mips*-sde*-elf*
1602 Support for these obsolete configurations has been removed.
1604 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1605 SGI Irix-5.x mips-*-irix5*
1606 SGI Irix-6.x mips-*-irix6*
1607 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1608 VAX running Ultrix vax-*-ultrix*
1610 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1611 and "assf"), have been removed. Use the "sharedlibrary" command, or
1612 its alias "share", instead.
1614 *** Changes in GDB 7.8
1616 * New command line options
1619 This is an alias for the --data-directory option.
1621 * GDB supports printing and modifying of variable length automatic arrays
1622 as specified in ISO C99.
1624 * The ARM simulator now supports instruction level tracing
1625 with or without disassembly.
1629 GDB now has support for scripting using Guile. Whether this is
1630 available is determined at configure time.
1631 Guile version 2.0 or greater is required.
1632 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1634 * New commands (for set/show, see "New options" below)
1638 Invoke CODE by passing it to the Guile interpreter.
1642 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1644 info auto-load guile-scripts [regexp]
1645 Print the list of automatically loaded Guile scripts.
1647 * The source command is now capable of sourcing Guile scripts.
1648 This feature is dependent on the debugger being built with Guile support.
1652 set print symbol-loading (off|brief|full)
1653 show print symbol-loading
1654 Control whether to print informational messages when loading symbol
1655 information for a file. The default is "full", but when debugging
1656 programs with large numbers of shared libraries the amount of output
1657 becomes less useful.
1659 set guile print-stack (none|message|full)
1660 show guile print-stack
1661 Show a stack trace when an error is encountered in a Guile script.
1663 set auto-load guile-scripts (on|off)
1664 show auto-load guile-scripts
1665 Control auto-loading of Guile script files.
1667 maint ada set ignore-descriptive-types (on|off)
1668 maint ada show ignore-descriptive-types
1669 Control whether the debugger should ignore descriptive types in Ada
1670 programs. The default is not to ignore the descriptive types. See
1671 the user manual for more details on descriptive types and the intended
1672 usage of this option.
1674 set auto-connect-native-target
1676 Control whether GDB is allowed to automatically connect to the
1677 native target for the run, attach, etc. commands when not connected
1678 to any target yet. See also "target native" below.
1680 set record btrace replay-memory-access (read-only|read-write)
1681 show record btrace replay-memory-access
1682 Control what memory accesses are allowed during replay.
1684 maint set target-async (on|off)
1685 maint show target-async
1686 This controls whether GDB targets operate in synchronous or
1687 asynchronous mode. Normally the default is asynchronous, if it is
1688 available; but this can be changed to more easily debug problems
1689 occurring only in synchronous mode.
1691 set mi-async (on|off)
1693 Control whether MI asynchronous mode is preferred. This supersedes
1694 "set target-async" of previous GDB versions.
1696 * "set target-async" is deprecated as a CLI option and is now an alias
1697 for "set mi-async" (only puts MI into async mode).
1699 * Background execution commands (e.g., "c&", "s&", etc.) are now
1700 possible ``out of the box'' if the target supports them. Previously
1701 the user would need to explicitly enable the possibility with the
1702 "set target-async on" command.
1704 * New features in the GDB remote stub, GDBserver
1706 ** New option --debug-format=option1[,option2,...] allows one to add
1707 additional text to each output. At present only timestamps
1708 are supported: --debug-format=timestamps.
1709 Timestamps can also be turned on with the
1710 "monitor set debug-format timestamps" command from GDB.
1712 * The 'record instruction-history' command now starts counting instructions
1713 at one. This also affects the instruction ranges reported by the
1714 'record function-call-history' command when given the /i modifier.
1716 * The command 'record function-call-history' supports a new modifier '/c' to
1717 indent the function names based on their call stack depth.
1718 The fields for the '/i' and '/l' modifier have been reordered.
1719 The source line range is now prefixed with 'at'.
1720 The instruction range is now prefixed with 'inst'.
1721 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1722 "record instruction-history" and "list" commands.
1724 * The ranges given as arguments to the 'record function-call-history' and
1725 'record instruction-history' commands are now inclusive.
1727 * The btrace record target now supports the 'record goto' command.
1728 For locations inside the execution trace, the back trace is computed
1729 based on the information stored in the execution trace.
1731 * The btrace record target supports limited reverse execution and replay.
1732 The target does not record data and therefore does not allow reading
1733 memory or registers.
1735 * The "catch syscall" command now works on s390*-linux* targets.
1737 * The "compare-sections" command is no longer specific to target
1738 remote. It now works with all targets.
1740 * All native targets are now consistently called "native".
1741 Consequently, the "target child", "target GNU", "target djgpp",
1742 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1743 commands have been replaced with "target native". The QNX/NTO port
1744 leaves the "procfs" target in place and adds a "native" target for
1745 consistency with other ports. The impact on users should be minimal
1746 as these commands previously either throwed an error, or were
1747 no-ops. The target's name is visible in the output of the following
1748 commands: "help target", "info target", "info files", "maint print
1751 * The "target native" command now connects to the native target. This
1752 can be used to launch native programs even when "set
1753 auto-connect-native-target" is set to off.
1755 * GDB now supports access to Intel MPX registers on GNU/Linux.
1757 * Support for Intel AVX-512 registers on GNU/Linux.
1758 Support displaying and modifying Intel AVX-512 registers
1759 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1761 * New remote packets
1763 qXfer:btrace:read's annex
1764 The qXfer:btrace:read packet supports a new annex 'delta' to read
1765 branch trace incrementally.
1769 ** Valid Python operations on gdb.Value objects representing
1770 structs/classes invoke the corresponding overloaded operators if
1772 ** New `Xmethods' feature in the Python API. Xmethods are
1773 additional methods or replacements for existing methods of a C++
1774 class. This feature is useful for those cases where a method
1775 defined in C++ source code could be inlined or optimized out by
1776 the compiler, making it unavailable to GDB.
1779 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1781 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1782 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1783 its alias "share", instead.
1785 * The commands "set remotebaud" and "show remotebaud" are no longer
1786 supported. Use "set serial baud" and "show serial baud" (respectively)
1791 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1792 target-async". The latter is left as a deprecated alias of the
1793 former for backward compatibility. If the target supports it,
1794 CLI background execution commands are now always possible by
1795 default, independently of whether the frontend stated a
1796 preference for asynchronous execution with "-gdb-set mi-async".
1797 Previously "-gdb-set target-async off" affected both MI execution
1798 commands and CLI execution commands.
1800 *** Changes in GDB 7.7
1802 * Improved support for process record-replay and reverse debugging on
1803 arm*-linux* targets. Support for thumb32 and syscall instruction
1804 recording has been added.
1806 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1808 * GDB now supports Fission DWP file format version 2.
1809 http://gcc.gnu.org/wiki/DebugFission
1811 * New convenience function "$_isvoid", to check whether an expression
1812 is void. A void expression is an expression where the type of the
1813 result is "void". For example, some convenience variables may be
1814 "void" when evaluated (e.g., "$_exitcode" before the execution of
1815 the program being debugged; or an undefined convenience variable).
1816 Another example, when calling a function whose return type is
1819 * The "maintenance print objfiles" command now takes an optional regexp.
1821 * The "catch syscall" command now works on arm*-linux* targets.
1823 * GDB now consistently shows "<not saved>" when printing values of
1824 registers the debug info indicates have not been saved in the frame
1825 and there's nowhere to retrieve them from
1826 (callee-saved/call-clobbered registers):
1831 (gdb) info registers rax
1834 Before, the former would print "<optimized out>", and the latter
1835 "*value not available*".
1837 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1842 ** Frame filters and frame decorators have been added.
1843 ** Temporary breakpoints are now supported.
1844 ** Line tables representation has been added.
1845 ** New attribute 'parent_type' for gdb.Field objects.
1846 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1847 ** New attribute 'name' for gdb.Type objects.
1851 Nios II ELF nios2*-*-elf
1852 Nios II GNU/Linux nios2*-*-linux
1853 Texas Instruments MSP430 msp430*-*-elf
1855 * Removed native configurations
1857 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1858 been removed. ELF variants of these configurations are kept supported.
1860 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1861 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1862 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1863 i[34567]86-*-openbsd3.[0-3]
1864 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1865 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1866 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1870 Like "catch throw", but catches a re-thrown exception.
1871 maint check-psymtabs
1872 Renamed from old "maint check-symtabs".
1874 Perform consistency checks on symtabs.
1875 maint expand-symtabs
1876 Expand symtabs matching an optional regexp.
1879 Display the details of GDB configure-time options.
1881 maint set|show per-command
1882 maint set|show per-command space
1883 maint set|show per-command time
1884 maint set|show per-command symtab
1885 Enable display of per-command gdb resource usage.
1887 remove-symbol-file FILENAME
1888 remove-symbol-file -a ADDRESS
1889 Remove a symbol file added via add-symbol-file. The file to remove
1890 can be identified by its filename or by an address that lies within
1891 the boundaries of this symbol file in memory.
1894 info exceptions REGEXP
1895 Display the list of Ada exceptions defined in the program being
1896 debugged. If provided, only the exceptions whose names match REGEXP
1901 set debug symfile off|on
1903 Control display of debugging info regarding reading symbol files and
1904 symbol tables within those files
1906 set print raw frame-arguments
1907 show print raw frame-arguments
1908 Set/show whether to print frame arguments in raw mode,
1909 disregarding any defined pretty-printers.
1911 set remote trace-status-packet
1912 show remote trace-status-packet
1913 Set/show the use of remote protocol qTStatus packet.
1917 Control display of debugging messages related to Nios II targets.
1921 Control whether target-assisted range stepping is enabled.
1923 set startup-with-shell
1924 show startup-with-shell
1925 Specifies whether Unix child processes are started via a shell or
1930 Use the target memory cache for accesses to the code segment. This
1931 improves performance of remote debugging (particularly disassembly).
1933 * You can now use a literal value 'unlimited' for options that
1934 interpret 0 or -1 as meaning "unlimited". E.g., "set
1935 trace-buffer-size unlimited" is now an alias for "set
1936 trace-buffer-size -1" and "set height unlimited" is now an alias for
1939 * The "set debug symtab-create" debugging option of GDB has been changed to
1940 accept a verbosity level. 0 means "off", 1 provides basic debugging
1941 output, and values of 2 or greater provides more verbose output.
1943 * New command-line options
1945 Display the details of GDB configure-time options.
1947 * The command 'tsave' can now support new option '-ctf' to save trace
1948 buffer in Common Trace Format.
1950 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1953 * GDB now implements the the C++ 'typeid' operator.
1955 * The new convenience variable $_exception holds the exception being
1956 thrown or caught at an exception-related catchpoint.
1958 * The exception-related catchpoints, like "catch throw", now accept a
1959 regular expression which can be used to filter exceptions by type.
1961 * The new convenience variable $_exitsignal is automatically set to
1962 the terminating signal number when the program being debugged dies
1963 due to an uncaught signal.
1967 ** All MI commands now accept an optional "--language" option.
1968 Support for this feature can be verified by using the "-list-features"
1969 command, which should contain "language-option".
1971 ** The new command -info-gdb-mi-command allows the user to determine
1972 whether a GDB/MI command is supported or not.
1974 ** The "^error" result record returned when trying to execute an undefined
1975 GDB/MI command now provides a variable named "code" whose content is the
1976 "undefined-command" error code. Support for this feature can be verified
1977 by using the "-list-features" command, which should contain
1978 "undefined-command-error-code".
1980 ** The -trace-save MI command can optionally save trace buffer in Common
1983 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1985 ** The command -data-list-register-values now accepts an optional
1986 "--skip-unavailable" option. When used, only the available registers
1989 ** The new command -trace-frame-collected dumps collected variables,
1990 computed expressions, tvars, memory and registers in a traceframe.
1992 ** The commands -stack-list-locals, -stack-list-arguments and
1993 -stack-list-variables now accept an option "--skip-unavailable".
1994 When used, only the available locals or arguments are displayed.
1996 ** The -exec-run command now accepts an optional "--start" option.
1997 When used, the command follows the same semantics as the "start"
1998 command, stopping the program's execution at the start of its
1999 main subprogram. Support for this feature can be verified using
2000 the "-list-features" command, which should contain
2001 "exec-run-start-option".
2003 ** The new commands -catch-assert and -catch-exceptions insert
2004 catchpoints stopping the program when Ada exceptions are raised.
2006 ** The new command -info-ada-exceptions provides the equivalent of
2007 the new "info exceptions" command.
2009 * New system-wide configuration scripts
2010 A GDB installation now provides scripts suitable for use as system-wide
2011 configuration scripts for the following systems:
2015 * GDB now supports target-assigned range stepping with remote targets.
2016 This improves the performance of stepping source lines by reducing
2017 the number of control packets from/to GDB. See "New remote packets"
2020 * GDB now understands the element 'tvar' in the XML traceframe info.
2021 It has the id of the collected trace state variables.
2023 * On S/390 targets that provide the transactional-execution feature,
2024 the program interruption transaction diagnostic block (TDB) is now
2025 represented as a number of additional "registers" in GDB.
2027 * New remote packets
2031 The vCont packet supports a new 'r' action, that tells the remote
2032 stub to step through an address range itself, without GDB
2033 involvemement at each single-step.
2035 qXfer:libraries-svr4:read's annex
2036 The previously unused annex of the qXfer:libraries-svr4:read packet
2037 is now used to support passing an argument list. The remote stub
2038 reports support for this argument list to GDB's qSupported query.
2039 The defined arguments are "start" and "prev", used to reduce work
2040 necessary for library list updating, resulting in significant
2043 * New features in the GDB remote stub, GDBserver
2045 ** GDBserver now supports target-assisted range stepping. Currently
2046 enabled on x86/x86_64 GNU/Linux targets.
2048 ** GDBserver now adds element 'tvar' in the XML in the reply to
2049 'qXfer:traceframe-info:read'. It has the id of the collected
2050 trace state variables.
2052 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2055 * New 'z' formatter for printing and examining memory, this displays the
2056 value as hexadecimal zero padded on the left to the size of the type.
2058 * GDB can now use Windows x64 unwinding data.
2060 * The "set remotebaud" command has been replaced by "set serial baud".
2061 Similarly, "show remotebaud" has been replaced by "show serial baud".
2062 The "set remotebaud" and "show remotebaud" commands are still available
2063 to provide backward compatibility with older versions of GDB.
2065 *** Changes in GDB 7.6
2067 * Target record has been renamed to record-full.
2068 Record/replay is now enabled with the "record full" command.
2069 This also affects settings that are associated with full record/replay
2070 that have been moved from "set/show record" to "set/show record full":
2072 set|show record full insn-number-max
2073 set|show record full stop-at-limit
2074 set|show record full memory-query
2076 * A new record target "record-btrace" has been added. The new target
2077 uses hardware support to record the control-flow of a process. It
2078 does not support replaying the execution, but it implements the
2079 below new commands for investigating the recorded execution log.
2080 This new recording method can be enabled using:
2084 The "record-btrace" target is only available on Intel Atom processors
2085 and requires a Linux kernel 2.6.32 or later.
2087 * Two new commands have been added for record/replay to give information
2088 about the recorded execution without having to replay the execution.
2089 The commands are only supported by "record btrace".
2091 record instruction-history prints the execution history at
2092 instruction granularity
2094 record function-call-history prints the execution history at
2095 function granularity
2097 * New native configurations
2099 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2100 FreeBSD/powerpc powerpc*-*-freebsd
2101 x86_64/Cygwin x86_64-*-cygwin*
2102 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2106 ARM AArch64 aarch64*-*-elf
2107 ARM AArch64 GNU/Linux aarch64*-*-linux
2108 Lynx 178 PowerPC powerpc-*-lynx*178
2109 x86_64/Cygwin x86_64-*-cygwin*
2110 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2112 * If the configured location of system.gdbinit file (as given by the
2113 --with-system-gdbinit option at configure time) is in the
2114 data-directory (as specified by --with-gdb-datadir at configure
2115 time) or in one of its subdirectories, then GDB will look for the
2116 system-wide init file in the directory specified by the
2117 --data-directory command-line option.
2119 * New command line options:
2121 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2122 other initialization files, unlike -nx which disables all of them.
2124 * Removed command line options
2126 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2129 * The 'ptype' and 'whatis' commands now accept an argument to control
2132 * 'info proc' now works on some core files.
2136 ** Vectors can be created with gdb.Type.vector.
2138 ** Python's atexit.register now works in GDB.
2140 ** Types can be pretty-printed via a Python API.
2142 ** Python 3 is now supported (in addition to Python 2.4 or later)
2144 ** New class gdb.Architecture exposes GDB's internal representation
2145 of architecture in the Python API.
2147 ** New method Frame.architecture returns the gdb.Architecture object
2148 corresponding to the frame's architecture.
2150 * New Python-based convenience functions:
2152 ** $_memeq(buf1, buf2, length)
2153 ** $_streq(str1, str2)
2155 ** $_regex(str, regex)
2157 * The 'cd' command now defaults to using '~' (the home directory) if not
2160 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2161 default for GCC since November 2000.
2163 * The command 'forward-search' can now be abbreviated as 'fo'.
2165 * The command 'info tracepoints' can now display 'installed on target'
2166 or 'not installed on target' for each non-pending location of tracepoint.
2168 * New configure options
2170 --enable-libmcheck/--disable-libmcheck
2171 By default, development versions are built with -lmcheck on hosts
2172 that support it, in order to help track memory corruption issues.
2173 Release versions, on the other hand, are built without -lmcheck
2174 by default. The --enable-libmcheck/--disable-libmcheck configure
2175 options allow the user to override that default.
2176 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2177 This configure option allows the user to build GDB with
2178 libbabeltrace using which GDB can read Common Trace Format data.
2180 * New commands (for set/show, see "New options" below)
2183 Catch signals. This is similar to "handle", but allows commands and
2184 conditions to be attached.
2187 List the BFDs known to GDB.
2189 python-interactive [command]
2191 Start a Python interactive prompt, or evaluate the optional command
2192 and print the result of expressions.
2195 "py" is a new alias for "python".
2197 enable type-printer [name]...
2198 disable type-printer [name]...
2199 Enable or disable type printers.
2203 ** For the Renesas Super-H architecture, the "regs" command has been removed
2204 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2209 set print type methods (on|off)
2210 show print type methods
2211 Control whether method declarations are displayed by "ptype".
2212 The default is to show them.
2214 set print type typedefs (on|off)
2215 show print type typedefs
2216 Control whether typedef definitions are displayed by "ptype".
2217 The default is to show them.
2219 set filename-display basename|relative|absolute
2220 show filename-display
2221 Control the way in which filenames is displayed.
2222 The default is "relative", which preserves previous behavior.
2224 set trace-buffer-size
2225 show trace-buffer-size
2226 Request target to change the size of trace buffer.
2228 set remote trace-buffer-size-packet auto|on|off
2229 show remote trace-buffer-size-packet
2230 Control the use of the remote protocol `QTBuffer:size' packet.
2234 Control display of debugging messages related to ARM AArch64.
2237 set debug coff-pe-read
2238 show debug coff-pe-read
2239 Control display of debugging messages related to reading of COFF/PE
2244 Control display of debugging messages related to Mach-O symbols
2247 set debug notification
2248 show debug notification
2249 Control display of debugging info for async remote notification.
2253 ** Command parameter changes are now notified using new async record
2254 "=cmd-param-changed".
2255 ** Trace frame changes caused by command "tfind" are now notified using
2256 new async record "=traceframe-changed".
2257 ** The creation, deletion and modification of trace state variables
2258 are now notified using new async records "=tsv-created",
2259 "=tsv-deleted" and "=tsv-modified".
2260 ** The start and stop of process record are now notified using new
2261 async record "=record-started" and "=record-stopped".
2262 ** Memory changes are now notified using new async record
2264 ** The data-disassemble command response will include a "fullname" field
2265 containing the absolute file name when source has been requested.
2266 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2267 command, to allow pattern filling of memory areas.
2268 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2269 library load/unload events.
2270 ** The response to breakpoint commands and breakpoint async records
2271 includes an "installed" field containing a boolean state about each
2272 non-pending tracepoint location is whether installed on target or not.
2273 ** Output of the "-trace-status" command includes a "trace-file" field
2274 containing the name of the trace file being examined. This field is
2275 optional, and only present when examining a trace file.
2276 ** The "fullname" field is now always present along with the "file" field,
2277 even if the file cannot be found by GDB.
2279 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2280 You must have the LZMA library available when configuring GDB for this
2281 feature to be enabled. For more information, see:
2282 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2284 * New remote packets
2287 Set the size of trace buffer. The remote stub reports support for this
2288 packet to gdb's qSupported query.
2291 Enable Branch Trace Store (BTS)-based branch tracing for the current
2292 thread. The remote stub reports support for this packet to gdb's
2296 Disable branch tracing for the current thread. The remote stub reports
2297 support for this packet to gdb's qSupported query.
2300 Read the traced branches for the current thread. The remote stub
2301 reports support for this packet to gdb's qSupported query.
2303 *** Changes in GDB 7.5
2305 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2306 for more x32 ABI info.
2308 * GDB now supports access to MIPS DSP registers on Linux targets.
2310 * GDB now supports debugging microMIPS binaries.
2312 * The "info os" command on GNU/Linux can now display information on
2313 several new classes of objects managed by the operating system:
2314 "info os procgroups" lists process groups
2315 "info os files" lists file descriptors
2316 "info os sockets" lists internet-domain sockets
2317 "info os shm" lists shared-memory regions
2318 "info os semaphores" lists semaphores
2319 "info os msg" lists message queues
2320 "info os modules" lists loaded kernel modules
2322 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2323 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2324 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2325 options and inspect the probe arguments using the new $_probe_arg family
2326 of convenience variables. You can obtain more information about SystemTap
2327 in <http://sourceware.org/systemtap/>.
2329 * GDB now supports reversible debugging on ARM, it allows you to
2330 debug basic ARM and THUMB instructions, and provides
2331 record/replay support.
2333 * The option "symbol-reloading" has been deleted as it is no longer used.
2337 ** GDB commands implemented in Python can now be put in command class
2340 ** The "maint set python print-stack on|off" is now deleted.
2342 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2343 apply "flag enum"-style pretty-printing to any enum.
2345 ** gdb.lookup_symbol can now work when there is no current frame.
2347 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2348 the source at which the symbol was defined.
2350 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2351 method 'value'. The former indicates whether the symbol needs a
2352 frame in order to compute its value, and the latter computes the
2355 ** A new method 'referenced_value' on gdb.Value objects which can
2356 dereference pointer as well as C++ reference values.
2358 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2359 which return the global and static blocks (as gdb.Block objects),
2360 of the underlying symbol table, respectively.
2362 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2363 object associated with a PC value.
2365 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2366 of the address range occupied by code for the current source line.
2368 * Go language support.
2369 GDB now supports debugging programs written in the Go programming
2372 * GDBserver now supports stdio connections.
2373 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2375 * The binary "gdbtui" can no longer be built or installed.
2376 Use "gdb -tui" instead.
2378 * GDB will now print "flag" enums specially. A flag enum is one where
2379 all the enumerator values have no bits in common when pairwise
2380 "and"ed. When printing a value whose type is a flag enum, GDB will
2381 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2382 (gdb) print (enum E) 3
2385 * The filename part of a linespec will now match trailing components
2386 of a source file name. For example, "break gcc/expr.c:1000" will
2387 now set a breakpoint in build/gcc/expr.c, but not
2388 build/libcpp/expr.c.
2390 * The "info proc" and "generate-core-file" commands will now also
2391 work on remote targets connected to GDBserver on Linux.
2393 * The command "info catch" has been removed. It has been disabled
2394 since December 2007.
2396 * The "catch exception" and "catch assert" commands now accept
2397 a condition at the end of the command, much like the "break"
2398 command does. For instance:
2400 (gdb) catch exception Constraint_Error if Barrier = True
2402 Previously, it was possible to add a condition to such catchpoints,
2403 but it had to be done as a second step, after the catchpoint had been
2404 created, using the "condition" command.
2406 * The "info static-tracepoint-marker" command will now also work on
2407 native Linux targets with in-process agent.
2409 * GDB can now set breakpoints on inlined functions.
2411 * The .gdb_index section has been updated to include symbols for
2412 inlined functions. GDB will ignore older .gdb_index sections by
2413 default, which could cause symbol files to be loaded more slowly
2414 until their .gdb_index sections can be recreated. The new command
2415 "set use-deprecated-index-sections on" will cause GDB to use any older
2416 .gdb_index sections it finds. This will restore performance, but the
2417 ability to set breakpoints on inlined functions will be lost in symbol
2418 files with older .gdb_index sections.
2420 The .gdb_index section has also been updated to record more information
2421 about each symbol. This speeds up the "info variables", "info functions"
2422 and "info types" commands when used with programs having the .gdb_index
2423 section, as well as speeding up debugging with shared libraries using
2424 the .gdb_index section.
2426 * Ada support for GDB/MI Variable Objects has been added.
2428 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2433 ** New command -info-os is the MI equivalent of "info os".
2435 ** Output logs ("set logging" and related) now include MI output.
2439 ** "set use-deprecated-index-sections on|off"
2440 "show use-deprecated-index-sections on|off"
2441 Controls the use of deprecated .gdb_index sections.
2443 ** "catch load" and "catch unload" can be used to stop when a shared
2444 library is loaded or unloaded, respectively.
2446 ** "enable count" can be used to auto-disable a breakpoint after
2449 ** "info vtbl" can be used to show the virtual method tables for
2450 C++ and Java objects.
2452 ** "explore" and its sub commands "explore value" and "explore type"
2453 can be used to recursively explore values and types of
2454 expressions. These commands are available only if GDB is
2455 configured with '--with-python'.
2457 ** "info auto-load" shows status of all kinds of auto-loaded files,
2458 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2459 sequences of commands files, "info auto-load python-scripts"
2460 shows status of auto-loading Python script files,
2461 "info auto-load local-gdbinit" shows status of loading init file
2462 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2463 status of inferior specific thread debugging shared library loading.
2465 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2466 and "show auto-load-scripts" commands have been deprecated, use their
2467 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2468 and "show auto-load python-scripts" counterparts instead.
2470 ** "dprintf location,format,args..." creates a dynamic printf, which
2471 is basically a breakpoint that does a printf and immediately
2472 resumes your program's execution, so it is like a printf that you
2473 can insert dynamically at runtime instead of at compiletime.
2475 ** "set print symbol"
2477 Controls whether GDB attempts to display the symbol, if any,
2478 corresponding to addresses it prints. This defaults to "on", but
2479 you can set it to "off" to restore GDB's previous behavior.
2481 * Deprecated commands
2483 ** For the Renesas Super-H architecture, the "regs" command has been
2484 deprecated, and "info all-registers" should be used instead.
2488 Renesas RL78 rl78-*-elf
2489 HP OpenVMS ia64 ia64-hp-openvms*
2491 * GDBserver supports evaluation of breakpoint conditions. When
2492 support is advertised by GDBserver, GDB may be told to send the
2493 breakpoint conditions in bytecode form to GDBserver. GDBserver
2494 will only report the breakpoint trigger to GDB when its condition
2499 set mips compression
2500 show mips compression
2501 Select the compressed ISA encoding used in functions that have no symbol
2502 information available. The encoding can be set to either of:
2505 and is updated automatically from ELF file flags if available.
2507 set breakpoint condition-evaluation
2508 show breakpoint condition-evaluation
2509 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2510 GDBserver ("target"). Default option "auto" chooses the most efficient
2512 This option can improve debugger efficiency depending on the speed of the
2516 Disable auto-loading globally.
2519 Show auto-loading setting of all kinds of auto-loaded files.
2521 set auto-load gdb-scripts on|off
2522 show auto-load gdb-scripts
2523 Control auto-loading of GDB canned sequences of commands files.
2525 set auto-load python-scripts on|off
2526 show auto-load python-scripts
2527 Control auto-loading of Python script files.
2529 set auto-load local-gdbinit on|off
2530 show auto-load local-gdbinit
2531 Control loading of init file (.gdbinit) from current directory.
2533 set auto-load libthread-db on|off
2534 show auto-load libthread-db
2535 Control auto-loading of inferior specific thread debugging shared library.
2537 set auto-load scripts-directory <dir1>[:<dir2>...]
2538 show auto-load scripts-directory
2539 Set a list of directories from which to load auto-loaded scripts.
2540 Automatically loaded Python scripts and GDB scripts are located in one
2541 of the directories listed by this option.
2542 The delimiter (':' above) may differ according to the host platform.
2544 set auto-load safe-path <dir1>[:<dir2>...]
2545 show auto-load safe-path
2546 Set a list of directories from which it is safe to auto-load files.
2547 The delimiter (':' above) may differ according to the host platform.
2549 set debug auto-load on|off
2550 show debug auto-load
2551 Control display of debugging info for auto-loading the files above.
2553 set dprintf-style gdb|call|agent
2555 Control the way in which a dynamic printf is performed; "gdb"
2556 requests a GDB printf command, while "call" causes dprintf to call a
2557 function in the inferior. "agent" requests that the target agent
2558 (such as GDBserver) do the printing.
2560 set dprintf-function <expr>
2561 show dprintf-function
2562 set dprintf-channel <expr>
2563 show dprintf-channel
2564 Set the function and optional first argument to the call when using
2565 the "call" style of dynamic printf.
2567 set disconnected-dprintf on|off
2568 show disconnected-dprintf
2569 Control whether agent-style dynamic printfs continue to be in effect
2570 after GDB disconnects.
2572 * New configure options
2574 --with-auto-load-dir
2575 Configure default value for the 'set auto-load scripts-directory'
2576 setting above. It defaults to '$debugdir:$datadir/auto-load',
2577 $debugdir representing global debugging info directories (available
2578 via 'show debug-file-directory') and $datadir representing GDB's data
2579 directory (available via 'show data-directory').
2581 --with-auto-load-safe-path
2582 Configure default value for the 'set auto-load safe-path' setting
2583 above. It defaults to the --with-auto-load-dir setting.
2585 --without-auto-load-safe-path
2586 Set 'set auto-load safe-path' to '/', effectively disabling this
2589 * New remote packets
2591 z0/z1 conditional breakpoints extension
2593 The z0/z1 breakpoint insertion packets have been extended to carry
2594 a list of conditional expressions over to the remote stub depending on the
2595 condition evaluation mode. The use of this extension can be controlled
2596 via the "set remote conditional-breakpoints-packet" command.
2600 Specify the signals which the remote stub may pass to the debugged
2601 program without GDB involvement.
2603 * New command line options
2605 --init-command=FILE, -ix Like --command, -x but execute it
2606 before loading inferior.
2607 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2608 execute it before loading inferior.
2610 *** Changes in GDB 7.4
2612 * GDB now handles ambiguous linespecs more consistently; the existing
2613 FILE:LINE support has been expanded to other types of linespecs. A
2614 breakpoint will now be set on all matching locations in all
2615 inferiors, and locations will be added or removed according to
2618 * GDB now allows you to skip uninteresting functions and files when
2619 stepping with the "skip function" and "skip file" commands.
2621 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2622 and "show remote hardware-watchpoint-length-limit". These allows to
2623 set or show the maximum length limit (in bytes) of a remote
2624 target hardware watchpoint.
2626 This allows e.g. to use "unlimited" hardware watchpoints with the
2627 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2628 watchpoints are slower than real hardware watchpoints but are
2629 significantly faster than gdb software watchpoints.
2633 ** The register_pretty_printer function in module gdb.printing now takes
2634 an optional `replace' argument. If True, the new printer replaces any
2637 ** The "maint set python print-stack on|off" command has been
2638 deprecated and will be deleted in GDB 7.5.
2639 A new command: "set python print-stack none|full|message" has
2640 replaced it. Additionally, the default for "print-stack" is
2641 now "message", which just prints the error message without
2644 ** A prompt substitution hook (prompt_hook) is now available to the
2647 ** A new Python module, gdb.prompt has been added to the GDB Python
2648 modules library. This module provides functionality for
2649 escape sequences in prompts (used by set/show
2650 extended-prompt). These escape sequences are replaced by their
2651 corresponding value.
2653 ** Python commands and convenience-functions located in
2654 'data-directory'/python/gdb/command and
2655 'data-directory'/python/gdb/function are now automatically loaded
2658 ** Blocks now provide four new attributes. global_block and
2659 static_block will return the global and static blocks
2660 respectively. is_static and is_global are boolean attributes
2661 that indicate if the block is one of those two types.
2663 ** Symbols now provide the "type" attribute, the type of the symbol.
2665 ** The "gdb.breakpoint" function has been deprecated in favor of
2668 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2669 of a function. This class is based on the "finish" command
2670 available in the CLI.
2672 ** Type objects for struct and union types now allow access to
2673 the fields using standard Python dictionary (mapping) methods.
2674 For example, "some_type['myfield']" now works, as does
2675 "some_type.items()".
2677 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2680 ** A new function, "deep_items" has been added to the gdb.types
2681 module in the GDB Python modules library. This function returns
2682 an iterator over the fields of a struct or union type. Unlike
2683 the standard Python "iteritems" method, it will recursively traverse
2684 any anonymous fields.
2688 ** "*stopped" events can report several new "reason"s, such as
2691 ** Breakpoint changes are now notified using new async records, like
2692 "=breakpoint-modified".
2694 ** New command -ada-task-info.
2696 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2697 $sdir specifies the default system locations of shared libraries.
2698 $pdir specifies the directory where the libpthread used by the application
2701 GDB no longer looks in $sdir and $pdir after it has searched the directories
2702 mentioned in libthread-db-search-path. If you want to search those
2703 directories, they must be specified in libthread-db-search-path.
2704 The default value of libthread-db-search-path on GNU/Linux and Solaris
2705 systems is now "$sdir:$pdir".
2707 $pdir is not supported by gdbserver, it is currently ignored.
2708 $sdir is supported by gdbserver.
2710 * New configure option --with-iconv-bin.
2711 When using the internationalization support like the one in the GNU C
2712 library, GDB will invoke the "iconv" program to get a list of supported
2713 character sets. If this program lives in a non-standard location, one can
2714 use this option to specify where to find it.
2716 * When natively debugging programs on PowerPC BookE processors running
2717 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2718 watchpoints, which specify a mask in addition to an address to watch.
2719 The mask specifies that some bits of an address (the bits which are
2720 reset in the mask) should be ignored when matching the address accessed
2721 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2722 section in the user manual for more details.
2724 * The new option --once causes GDBserver to stop listening for connections once
2725 the first connection is made. The listening port used by GDBserver will
2726 become available after that.
2728 * New commands "info macros" and "alias" have been added.
2730 * New function parameters suffix @entry specifies value of function parameter
2731 at the time the function got called. Entry values are available only since
2737 "!" is now an alias of the "shell" command.
2738 Note that no space is needed between "!" and SHELL COMMAND.
2742 watch EXPRESSION mask MASK_VALUE
2743 The watch command now supports the mask argument which allows creation
2744 of masked watchpoints, if the current architecture supports this feature.
2746 info auto-load-scripts [REGEXP]
2747 This command was formerly named "maintenance print section-scripts".
2748 It is now generally useful and is no longer a maintenance-only command.
2750 info macro [-all] [--] MACRO
2751 The info macro command has new options `-all' and `--'. The first for
2752 printing all definitions of a macro. The second for explicitly specifying
2753 the end of arguments and the beginning of the macro name in case the macro
2754 name starts with a hyphen.
2756 collect[/s] EXPRESSIONS
2757 The tracepoint collect command now takes an optional modifier "/s"
2758 that directs it to dereference pointer-to-character types and
2759 collect the bytes of memory up to a zero byte. The behavior is
2760 similar to what you see when you use the regular print command on a
2761 string. An optional integer following the "/s" sets a bound on the
2762 number of bytes that will be collected.
2765 The trace start command now interprets any supplied arguments as a
2766 note to be recorded with the trace run, with an effect similar to
2767 setting the variable trace-notes.
2770 The trace stop command now interprets any arguments as a note to be
2771 mentioned along with the tstatus report that the trace was stopped
2772 with a command. The effect is similar to setting the variable
2775 * Tracepoints can now be enabled and disabled at any time after a trace
2776 experiment has been started using the standard "enable" and "disable"
2777 commands. It is now possible to start a trace experiment with no enabled
2778 tracepoints; GDB will display a warning, but will allow the experiment to
2779 begin, assuming that tracepoints will be enabled as needed while the trace
2782 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2783 locations with 4-byte instructions, when they were previously
2784 limited to locations with instructions of 5 bytes or longer.
2788 set debug dwarf2-read
2789 show debug dwarf2-read
2790 Turns on or off display of debugging messages related to reading
2791 DWARF debug info. The default is off.
2793 set debug symtab-create
2794 show debug symtab-create
2795 Turns on or off display of debugging messages related to symbol table
2796 creation. The default is off.
2799 show extended-prompt
2800 Set the GDB prompt, and allow escape sequences to be inserted to
2801 display miscellaneous information (see 'help set extended-prompt'
2802 for the list of sequences). This prompt (and any information
2803 accessed through the escape sequences) is updated every time the
2804 prompt is displayed.
2806 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2807 show print entry-values
2808 Set printing of frame argument values at function entry. In some cases
2809 GDB can determine the value of function argument which was passed by the
2810 function caller, even if the value was modified inside the called function.
2812 set debug entry-values
2813 show debug entry-values
2814 Control display of debugging info for determining frame argument values at
2815 function entry and virtual tail call frames.
2817 set basenames-may-differ
2818 show basenames-may-differ
2819 Set whether a source file may have multiple base names.
2820 (A "base name" is the name of a file with the directory part removed.
2821 Example: The base name of "/home/user/hello.c" is "hello.c".)
2822 If set, GDB will canonicalize file names (e.g., expand symlinks)
2823 before comparing them. Canonicalization is an expensive operation,
2824 but it allows the same file be known by more than one base name.
2825 If not set (the default), all source files are assumed to have just
2826 one base name, and gdb will do file name comparisons more efficiently.
2832 Set a user name and notes for the current and any future trace runs.
2833 This is useful for long-running and/or disconnected traces, to
2834 inform others (or yourself) as to who is running the trace, supply
2835 contact information, or otherwise explain what is going on.
2837 set trace-stop-notes
2838 show trace-stop-notes
2839 Set a note attached to the trace run, that is displayed when the
2840 trace has been stopped by a tstop command. This is useful for
2841 instance as an explanation, if you are stopping a trace run that was
2842 started by someone else.
2844 * New remote packets
2848 Dynamically enable a tracepoint in a started trace experiment.
2852 Dynamically disable a tracepoint in a started trace experiment.
2856 Set the user and notes of the trace run.
2860 Query the current status of a tracepoint.
2864 Query the minimum length of instruction at which a fast tracepoint may
2867 * Dcache size (number of lines) and line-size are now runtime-configurable
2868 via "set dcache line" and "set dcache line-size" commands.
2872 Texas Instruments TMS320C6x tic6x-*-*
2876 Renesas RL78 rl78-*-elf
2878 *** Changes in GDB 7.3.1
2880 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2882 *** Changes in GDB 7.3
2884 * GDB has a new command: "thread find [REGEXP]".
2885 It finds the thread id whose name, target id, or thread extra info
2886 matches the given regular expression.
2888 * The "catch syscall" command now works on mips*-linux* targets.
2890 * The -data-disassemble MI command now supports modes 2 and 3 for
2891 dumping the instruction opcodes.
2893 * New command line options
2895 -data-directory DIR Specify DIR as the "data-directory".
2896 This is mostly for testing purposes.
2898 * The "maint set python auto-load on|off" command has been renamed to
2899 "set auto-load-scripts on|off".
2901 * GDB has a new command: "set directories".
2902 It is like the "dir" command except that it replaces the
2903 source path list instead of augmenting it.
2905 * GDB now understands thread names.
2907 On GNU/Linux, "info threads" will display the thread name as set by
2908 prctl or pthread_setname_np.
2910 There is also a new command, "thread name", which can be used to
2911 assign a name internally for GDB to display.
2914 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2915 has been integrated into GDB.
2919 ** The function gdb.Write now accepts an optional keyword 'stream'.
2920 This keyword, when provided, will direct the output to either
2921 stdout, stderr, or GDB's logging output.
2923 ** Parameters can now be be sub-classed in Python, and in particular
2924 you may implement the get_set_doc and get_show_doc functions.
2925 This improves how Parameter set/show documentation is processed
2926 and allows for more dynamic content.
2928 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2929 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2930 have an is_valid method.
2932 ** Breakpoints can now be sub-classed in Python, and in particular
2933 you may implement a 'stop' function that is executed each time
2934 the inferior reaches that breakpoint.
2936 ** New function gdb.lookup_global_symbol looks up a global symbol.
2938 ** GDB values in Python are now callable if the value represents a
2939 function. For example, if 'some_value' represents a function that
2940 takes two integer parameters and returns a value, you can call
2941 that function like so:
2943 result = some_value (10,20)
2945 ** Module gdb.types has been added.
2946 It contains a collection of utilities for working with gdb.Types objects:
2947 get_basic_type, has_field, make_enum_dict.
2949 ** Module gdb.printing has been added.
2950 It contains utilities for writing and registering pretty-printers.
2951 New classes: PrettyPrinter, SubPrettyPrinter,
2952 RegexpCollectionPrettyPrinter.
2953 New function: register_pretty_printer.
2955 ** New commands "info pretty-printers", "enable pretty-printer" and
2956 "disable pretty-printer" have been added.
2958 ** gdb.parameter("directories") is now available.
2960 ** New function gdb.newest_frame returns the newest frame in the
2963 ** The gdb.InferiorThread class has a new "name" attribute. This
2964 holds the thread's name.
2966 ** Python Support for Inferior events.
2967 Python scripts can add observers to be notified of events
2968 occurring in the process being debugged.
2969 The following events are currently supported:
2970 - gdb.events.cont Continue event.
2971 - gdb.events.exited Inferior exited event.
2972 - gdb.events.stop Signal received, and Breakpoint hit events.
2976 ** GDB now puts template parameters in scope when debugging in an
2977 instantiation. For example, if you have:
2979 template<int X> int func (void) { return X; }
2981 then if you step into func<5>, "print X" will show "5". This
2982 feature requires proper debuginfo support from the compiler; it
2983 was added to GCC 4.5.
2985 ** The motion commands "next", "finish", "until", and "advance" now
2986 work better when exceptions are thrown. In particular, GDB will
2987 no longer lose control of the inferior; instead, the GDB will
2988 stop the inferior at the point at which the exception is caught.
2989 This functionality requires a change in the exception handling
2990 code that was introduced in GCC 4.5.
2992 * GDB now follows GCC's rules on accessing volatile objects when
2993 reading or writing target state during expression evaluation.
2994 One notable difference to prior behavior is that "print x = 0"
2995 no longer generates a read of x; the value of the assignment is
2996 now always taken directly from the value being assigned.
2998 * GDB now has some support for using labels in the program's source in
2999 linespecs. For instance, you can use "advance label" to continue
3000 execution to a label.
3002 * GDB now has support for reading and writing a new .gdb_index
3003 section. This section holds a fast index of DWARF debugging
3004 information and can be used to greatly speed up GDB startup and
3005 operation. See the documentation for `save gdb-index' for details.
3007 * The "watch" command now accepts an optional "-location" argument.
3008 When used, this causes GDB to watch the memory referred to by the
3009 expression. Such a watchpoint is never deleted due to it going out
3012 * GDB now supports thread debugging of core dumps on GNU/Linux.
3014 GDB now activates thread debugging using the libthread_db library
3015 when debugging GNU/Linux core dumps, similarly to when debugging
3016 live processes. As a result, when debugging a core dump file, GDB
3017 is now able to display pthread_t ids of threads. For example, "info
3018 threads" shows the same output as when debugging the process when it
3019 was live. In earlier releases, you'd see something like this:
3022 * 1 LWP 6780 main () at main.c:10
3024 While now you see this:
3027 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3029 It is also now possible to inspect TLS variables when debugging core
3032 When debugging a core dump generated on a machine other than the one
3033 used to run GDB, you may need to point GDB at the correct
3034 libthread_db library with the "set libthread-db-search-path"
3035 command. See the user manual for more details on this command.
3037 * When natively debugging programs on PowerPC BookE processors running
3038 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3039 which stop execution of the inferior whenever it executes an instruction
3040 at any address within the specified range. See the "PowerPC Embedded"
3041 section in the user manual for more details.
3043 * New features in the GDB remote stub, GDBserver
3045 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3046 and i686 LynxOS (version 5.x).
3048 ** GDBserver is now supported on Blackfin Linux.
3050 * New native configurations
3052 ia64 HP-UX ia64-*-hpux*
3056 Analog Devices, Inc. Blackfin Processor bfin-*
3058 * Ada task switching is now supported on sparc-elf targets when
3059 debugging a program using the Ravenscar Profile. For more information,
3060 see the "Tasking Support when using the Ravenscar Profile" section
3061 in the GDB user manual.
3063 * Guile support was removed.
3065 * New features in the GNU simulator
3067 ** The --map-info flag lists all known core mappings.
3069 ** CFI flashes may be simulated via the "cfi" device.
3071 *** Changes in GDB 7.2
3073 * Shared library support for remote targets by default
3075 When GDB is configured for a generic, non-OS specific target, like
3076 for example, --target=arm-eabi or one of the many *-*-elf targets,
3077 GDB now queries remote stubs for loaded shared libraries using the
3078 `qXfer:libraries:read' packet. Previously, shared library support
3079 was always disabled for such configurations.
3083 ** Argument Dependent Lookup (ADL)
3085 In C++ ADL lookup directs function search to the namespaces of its
3086 arguments even if the namespace has not been imported.
3096 Here the compiler will search for `foo' in the namespace of 'b'
3097 and find A::foo. GDB now supports this. This construct is commonly
3098 used in the Standard Template Library for operators.
3100 ** Improved User Defined Operator Support
3102 In addition to member operators, GDB now supports lookup of operators
3103 defined in a namespace and imported with a `using' directive, operators
3104 defined in the global scope, operators imported implicitly from an
3105 anonymous namespace, and the ADL operators mentioned in the previous
3107 GDB now also supports proper overload resolution for all the previously
3108 mentioned flavors of operators.
3110 ** static const class members
3112 Printing of static const class members that are initialized in the
3113 class definition has been fixed.
3115 * Windows Thread Information Block access.
3117 On Windows targets, GDB now supports displaying the Windows Thread
3118 Information Block (TIB) structure. This structure is visible either
3119 by using the new command `info w32 thread-information-block' or, by
3120 dereferencing the new convenience variable named `$_tlb', a
3121 thread-specific pointer to the TIB. This feature is also supported
3122 when remote debugging using GDBserver.
3124 * Static tracepoints
3126 Static tracepoints are calls in the user program into a tracing
3127 library. One such library is a port of the LTTng kernel tracer to
3128 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3129 When debugging with GDBserver, GDB now supports combining the GDB
3130 tracepoint machinery with such libraries. For example: the user can
3131 use GDB to probe a static tracepoint marker (a call from the user
3132 program into the tracing library) with the new "strace" command (see
3133 "New commands" below). This creates a "static tracepoint" in the
3134 breakpoint list, that can be manipulated with the same feature set
3135 as fast and regular tracepoints. E.g., collect registers, local and
3136 global variables, collect trace state variables, and define
3137 tracepoint conditions. In addition, the user can collect extra
3138 static tracepoint marker specific data, by collecting the new
3139 $_sdata internal variable. When analyzing the trace buffer, you can
3140 inspect $_sdata like any other variable available to GDB. For more
3141 information, see the "Tracepoints" chapter in GDB user manual. New
3142 remote packets have been defined to support static tracepoints, see
3143 the "New remote packets" section below.
3145 * Better reconstruction of tracepoints after disconnected tracing
3147 GDB will attempt to download the original source form of tracepoint
3148 definitions when starting a trace run, and then will upload these
3149 upon reconnection to the target, resulting in a more accurate
3150 reconstruction of the tracepoints that are in use on the target.
3154 You can now exercise direct control over the ways that GDB can
3155 affect your program. For instance, you can disallow the setting of
3156 breakpoints, so that the program can run continuously (assuming
3157 non-stop mode). In addition, the "observer" variable is available
3158 to switch all of the different controls; in observer mode, GDB
3159 cannot affect the target's behavior at all, which is useful for
3160 tasks like diagnosing live systems in the field.
3162 * The new convenience variable $_thread holds the number of the
3165 * New remote packets
3169 Return the address of the Windows Thread Information Block of a given thread.
3173 In response to several of the tracepoint packets, the target may now
3174 also respond with a number of intermediate `qRelocInsn' request
3175 packets before the final result packet, to have GDB handle
3176 relocating an instruction to execute at a different address. This
3177 is particularly useful for stubs that support fast tracepoints. GDB
3178 reports support for this feature in the qSupported packet.
3182 List static tracepoint markers in the target program.
3186 List static tracepoint markers at a given address in the target
3189 qXfer:statictrace:read
3191 Read the static trace data collected (by a `collect $_sdata'
3192 tracepoint action). The remote stub reports support for this packet
3193 to gdb's qSupported query.
3197 Send the current settings of GDB's permission flags.
3201 Send part of the source (textual) form of a tracepoint definition,
3202 which includes location, conditional, and action list.
3204 * The source command now accepts a -s option to force searching for the
3205 script in the source search path even if the script name specifies
3208 * New features in the GDB remote stub, GDBserver
3210 - GDBserver now support tracepoints (including fast tracepoints, and
3211 static tracepoints). The feature is currently supported by the
3212 i386-linux and amd64-linux builds. See the "Tracepoints support
3213 in gdbserver" section in the manual for more information.
3215 GDBserver JIT compiles the tracepoint's conditional agent
3216 expression bytecode into native code whenever possible for low
3217 overhead dynamic tracepoints conditionals. For such tracepoints,
3218 an expression that examines program state is evaluated when the
3219 tracepoint is reached, in order to determine whether to capture
3220 trace data. If the condition is simple and false, processing the
3221 tracepoint finishes very quickly and no data is gathered.
3223 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3224 for static tracepoints support.
3226 - GDBserver now supports x86_64 Windows 64-bit debugging.
3228 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3229 it understands register description.
3231 * The --batch flag now disables pagination and queries.
3233 * X86 general purpose registers
3235 GDB now supports reading/writing byte, word and double-word x86
3236 general purpose registers directly. This means you can use, say,
3237 $ah or $ax to refer, respectively, to the byte register AH and
3238 16-bit word register AX that are actually portions of the 32-bit
3239 register EAX or 64-bit register RAX.
3241 * The `commands' command now accepts a range of breakpoints to modify.
3242 A plain `commands' following a command that creates multiple
3243 breakpoints affects all the breakpoints set by that command. This
3244 applies to breakpoints set by `rbreak', and also applies when a
3245 single `break' command creates multiple breakpoints (e.g.,
3246 breakpoints on overloaded c++ functions).
3248 * The `rbreak' command now accepts a filename specification as part of
3249 its argument, limiting the functions selected by the regex to those
3250 in the specified file.
3252 * Support for remote debugging Windows and SymbianOS shared libraries
3253 from Unix hosts has been improved. Non Windows GDB builds now can
3254 understand target reported file names that follow MS-DOS based file
3255 system semantics, such as file names that include drive letters and
3256 use the backslash character as directory separator. This makes it
3257 possible to transparently use the "set sysroot" and "set
3258 solib-search-path" on Unix hosts to point as host copies of the
3259 target's shared libraries. See the new command "set
3260 target-file-system-kind" described below, and the "Commands to
3261 specify files" section in the user manual for more information.
3265 eval template, expressions...
3266 Convert the values of one or more expressions under the control
3267 of the string template to a command line, and call it.
3269 set target-file-system-kind unix|dos-based|auto
3270 show target-file-system-kind
3271 Set or show the assumed file system kind for target reported file
3274 save breakpoints <filename>
3275 Save all current breakpoint definitions to a file suitable for use
3276 in a later debugging session. To read the saved breakpoint
3277 definitions, use the `source' command.
3279 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3282 info static-tracepoint-markers
3283 Display information about static tracepoint markers in the target.
3285 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3286 Define a static tracepoint by probing a marker at the given
3287 function, line, address, or marker ID.
3291 Enable and disable observer mode.
3293 set may-write-registers on|off
3294 set may-write-memory on|off
3295 set may-insert-breakpoints on|off
3296 set may-insert-tracepoints on|off
3297 set may-insert-fast-tracepoints on|off
3298 set may-interrupt on|off
3299 Set individual permissions for GDB effects on the target. Note that
3300 some of these settings can have undesirable or surprising
3301 consequences, particularly when changed in the middle of a session.
3302 For instance, disabling the writing of memory can prevent
3303 breakpoints from being inserted, cause single-stepping to fail, or
3304 even crash your program, if you disable after breakpoints have been
3305 inserted. However, GDB should not crash.
3307 set record memory-query on|off
3308 show record memory-query
3309 Control whether to stop the inferior if memory changes caused
3310 by an instruction cannot be recorded.
3315 The disassemble command now supports "start,+length" form of two arguments.
3319 ** GDB now provides a new directory location, called the python directory,
3320 where Python scripts written for GDB can be installed. The location
3321 of that directory is <data-directory>/python, where <data-directory>
3322 is the GDB data directory. For more details, see section `Scripting
3323 GDB using Python' in the manual.
3325 ** The GDB Python API now has access to breakpoints, symbols, symbol
3326 tables, program spaces, inferiors, threads and frame's code blocks.
3327 Additionally, GDB Parameters can now be created from the API, and
3328 manipulated via set/show in the CLI.
3330 ** New functions gdb.target_charset, gdb.target_wide_charset,
3331 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3333 ** New exception gdb.GdbError.
3335 ** Pretty-printers are now also looked up in the current program space.
3337 ** Pretty-printers can now be individually enabled and disabled.
3339 ** GDB now looks for names of Python scripts to auto-load in a
3340 special section named `.debug_gdb_scripts', in addition to looking
3341 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3343 * Tracepoint actions were unified with breakpoint commands. In particular,
3344 there are no longer differences in "info break" output for breakpoints and
3345 tracepoints and the "commands" command can be used for both tracepoints and
3346 regular breakpoints.
3350 ARM Symbian arm*-*-symbianelf*
3352 * D language support.
3353 GDB now supports debugging programs written in the D programming
3356 * GDB now supports the extended ptrace interface for PowerPC which is
3357 available since Linux kernel version 2.6.34. This automatically enables
3358 any hardware breakpoints and additional hardware watchpoints available in
3359 the processor. The old ptrace interface exposes just one hardware
3360 watchpoint and no hardware breakpoints.
3362 * GDB is now able to use the Data Value Compare (DVC) register available on
3363 embedded PowerPC processors to implement in hardware simple watchpoint
3364 conditions of the form:
3366 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3368 This works in native GDB running on Linux kernels with the extended ptrace
3369 interface mentioned above.
3371 *** Changes in GDB 7.1
3375 ** Namespace Support
3377 GDB now supports importing of namespaces in C++. This enables the
3378 user to inspect variables from imported namespaces. Support for
3379 namepace aliasing has also been added. So, if a namespace is
3380 aliased in the current scope (e.g. namepace C=A; ) the user can
3381 print variables using the alias (e.g. (gdb) print C::x).
3385 All known bugs relating to the printing of virtual base class were
3386 fixed. It is now possible to call overloaded static methods using a
3391 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3392 and reinterpret_cast<> are now handled by the C++ expression parser.
3396 Xilinx MicroBlaze microblaze-*-*
3401 Xilinx MicroBlaze microblaze
3404 * Multi-program debugging.
3406 GDB now has support for multi-program (a.k.a. multi-executable or
3407 multi-exec) debugging. This allows for debugging multiple inferiors
3408 simultaneously each running a different program under the same GDB
3409 session. See "Debugging Multiple Inferiors and Programs" in the
3410 manual for more information. This implied some user visible changes
3411 in the multi-inferior support. For example, "info inferiors" now
3412 lists inferiors that are not running yet or that have exited
3413 already. See also "New commands" and "New options" below.
3415 * New tracing features
3417 GDB's tracepoint facility now includes several new features:
3419 ** Trace state variables
3421 GDB tracepoints now include support for trace state variables, which
3422 are variables managed by the target agent during a tracing
3423 experiment. They are useful for tracepoints that trigger each
3424 other, so for instance one tracepoint can count hits in a variable,
3425 and then a second tracepoint has a condition that is true when the
3426 count reaches a particular value. Trace state variables share the
3427 $-syntax of GDB convenience variables, and can appear in both
3428 tracepoint actions and condition expressions. Use the "tvariable"
3429 command to create, and "info tvariables" to view; see "Trace State
3430 Variables" in the manual for more detail.
3434 GDB now includes an option for defining fast tracepoints, which
3435 targets may implement more efficiently, such as by installing a jump
3436 into the target agent rather than a trap instruction. The resulting
3437 speedup can be by two orders of magnitude or more, although the
3438 tradeoff is that some program locations on some target architectures
3439 might not allow fast tracepoint installation, for instance if the
3440 instruction to be replaced is shorter than the jump. To request a
3441 fast tracepoint, use the "ftrace" command, with syntax identical to
3442 the regular trace command.
3444 ** Disconnected tracing
3446 It is now possible to detach GDB from the target while it is running
3447 a trace experiment, then reconnect later to see how the experiment
3448 is going. In addition, a new variable disconnected-tracing lets you
3449 tell the target agent whether to continue running a trace if the
3450 connection is lost unexpectedly.
3454 GDB now has the ability to save the trace buffer into a file, and
3455 then use that file as a target, similarly to you can do with
3456 corefiles. You can select trace frames, print data that was
3457 collected in them, and use tstatus to display the state of the
3458 tracing run at the moment that it was saved. To create a trace
3459 file, use "tsave <filename>", and to use it, do "target tfile
3462 ** Circular trace buffer
3464 You can ask the target agent to handle the trace buffer as a
3465 circular buffer, discarding the oldest trace frames to make room for
3466 newer ones, by setting circular-trace-buffer to on. This feature may
3467 not be available for all target agents.
3472 The disassemble command, when invoked with two arguments, now requires
3473 the arguments to be comma-separated.
3476 The info variables command now displays variable definitions. Files
3477 which only declare a variable are not shown.
3480 The source command is now capable of sourcing Python scripts.
3481 This feature is dependent on the debugger being build with Python
3484 Related to this enhancement is also the introduction of a new command
3485 "set script-extension" (see below).
3487 * New commands (for set/show, see "New options" below)
3489 record save [<FILENAME>]
3490 Save a file (in core file format) containing the process record
3491 execution log for replay debugging at a later time.
3493 record restore <FILENAME>
3494 Restore the process record execution log that was saved at an
3495 earlier time, for replay debugging.
3497 add-inferior [-copies <N>] [-exec <FILENAME>]
3500 clone-inferior [-copies <N>] [ID]
3501 Make a new inferior ready to execute the same program another
3502 inferior has loaded.
3507 maint info program-spaces
3508 List the program spaces loaded into GDB.
3510 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3511 show remote interrupt-sequence
3512 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3513 as the sequence to the remote target in order to interrupt the execution.
3514 Ctrl-C is a default. Some system prefers BREAK which is high level of
3515 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3516 Magic SysRq g. It is BREAK signal and character 'g'.
3518 set remote interrupt-on-connect [on | off]
3519 show remote interrupt-on-connect
3520 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3521 remote target when gdb connects to it. This is needed when you debug
3524 set remotebreak [on | off]
3526 Deprecated. Use "set/show remote interrupt-sequence" instead.
3528 tvariable $NAME [ = EXP ]
3529 Create or modify a trace state variable.
3532 List trace state variables and their values.
3534 delete tvariable $NAME ...
3535 Delete one or more trace state variables.
3538 Evaluate the given expressions without collecting anything into the
3539 trace buffer. (Valid in tracepoint actions only.)
3541 ftrace FN / FILE:LINE / *ADDR
3542 Define a fast tracepoint at the given function, line, or address.
3544 * New expression syntax
3546 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3547 GDB now parses 0b101010 identically with 42.
3551 set follow-exec-mode new|same
3552 show follow-exec-mode
3553 Control whether GDB reuses the same inferior across an exec call or
3554 creates a new one. This is useful to be able to restart the old
3555 executable after the inferior having done an exec call.
3557 set default-collect EXPR, ...
3558 show default-collect
3559 Define a list of expressions to be collected at each tracepoint.
3560 This is a useful way to ensure essential items are not overlooked,
3561 such as registers or a critical global variable.
3563 set disconnected-tracing
3564 show disconnected-tracing
3565 If set to 1, the target is instructed to continue tracing if it
3566 loses its connection to GDB. If 0, the target is to stop tracing
3569 set circular-trace-buffer
3570 show circular-trace-buffer
3571 If set to on, the target is instructed to use a circular trace buffer
3572 and discard the oldest trace frames instead of stopping the trace due
3573 to a full trace buffer. If set to off, the trace stops when the buffer
3574 fills up. Some targets may not support this.
3576 set script-extension off|soft|strict
3577 show script-extension
3578 If set to "off", the debugger does not perform any script language
3579 recognition, and all sourced files are assumed to be GDB scripts.
3580 If set to "soft" (the default), files are sourced according to
3581 filename extension, falling back to GDB scripts if the first
3583 If set to "strict", files are sourced according to filename extension.
3585 set ada trust-PAD-over-XVS on|off
3586 show ada trust-PAD-over-XVS
3587 If off, activate a workaround against a bug in the debugging information
3588 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3589 the GCC sources for more information about the GNAT encoding and
3590 PAD types in particular). It is always safe to set this option to
3591 off, but this introduces a slight performance penalty. The default
3594 * Python API Improvements
3596 ** GDB provides the new class gdb.LazyString. This is useful in
3597 some pretty-printing cases. The new method gdb.Value.lazy_string
3598 provides a simple way to create objects of this type.
3600 ** The fields returned by gdb.Type.fields now have an
3601 `is_base_class' attribute.
3603 ** The new method gdb.Type.range returns the range of an array type.
3605 ** The new method gdb.parse_and_eval can be used to parse and
3606 evaluate an expression.
3608 * New remote packets
3611 Define a trace state variable.
3614 Get the current value of a trace state variable.
3617 Set desired tracing behavior upon disconnection.
3620 Set the trace buffer to be linear or circular.
3623 Get data about the tracepoints currently in use.
3627 Process record now works correctly with hardware watchpoints.
3629 Multiple bug fixes have been made to the mips-irix port, making it
3630 much more reliable. In particular:
3631 - Debugging threaded applications is now possible again. Previously,
3632 GDB would hang while starting the program, or while waiting for
3633 the program to stop at a breakpoint.
3634 - Attaching to a running process no longer hangs.
3635 - An error occurring while loading a core file has been fixed.
3636 - Changing the value of the PC register now works again. This fixes
3637 problems observed when using the "jump" command, or when calling
3638 a function from GDB, or even when assigning a new value to $pc.
3639 - With the "finish" and "return" commands, the return value for functions
3640 returning a small array is now correctly printed.
3641 - It is now possible to break on shared library code which gets executed
3642 during a shared library init phase (code executed while executing
3643 their .init section). Previously, the breakpoint would have no effect.
3644 - GDB is now able to backtrace through the signal handler for
3645 non-threaded programs.
3647 PIE (Position Independent Executable) programs debugging is now supported.
3648 This includes debugging execution of PIC (Position Independent Code) shared
3649 libraries although for that, it should be possible to run such libraries as an
3652 *** Changes in GDB 7.0
3654 * GDB now has an interface for JIT compilation. Applications that
3655 dynamically generate code can create symbol files in memory and register
3656 them with GDB. For users, the feature should work transparently, and
3657 for JIT developers, the interface is documented in the GDB manual in the
3658 "JIT Compilation Interface" chapter.
3660 * Tracepoints may now be conditional. The syntax is as for
3661 breakpoints; either an "if" clause appended to the "trace" command,
3662 or the "condition" command is available. GDB sends the condition to
3663 the target for evaluation using the same bytecode format as is used
3664 for tracepoint actions.
3666 * The disassemble command now supports: an optional /r modifier, print the
3667 raw instructions in hex as well as in symbolic form, and an optional /m
3668 modifier to print mixed source+assembly.
3670 * Process record and replay
3672 In a architecture environment that supports ``process record and
3673 replay'', ``process record and replay'' target can record a log of
3674 the process execution, and replay it with both forward and reverse
3677 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3678 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3679 set execution-direction {forward|reverse}, for targets that support
3682 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3683 feature is available with a native GDB running on kernel version
3686 * GDB now has support for multi-byte and wide character sets on the
3687 target. Strings whose character type is wchar_t, char16_t, or
3688 char32_t are now correctly printed. GDB supports wide- and unicode-
3689 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3690 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3691 `printf'. This feature requires iconv to work properly; if your
3692 system does not have a working iconv, GDB can use GNU libiconv. See
3693 the installation instructions for more information.
3695 * GDB now supports automatic retrieval of shared library files from
3696 remote targets. To use this feature, specify a system root that begins
3697 with the `remote:' prefix, either via the `set sysroot' command or via
3698 the `--with-sysroot' configure-time option.
3700 * "info sharedlibrary" now takes an optional regex of libraries to show,
3701 and it now reports if a shared library has no debugging information.
3703 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3704 now complete on file names.
3706 * When completing in expressions, gdb will attempt to limit
3707 completions to allowable structure or union fields, where appropriate.
3708 For instance, consider:
3710 # struct example { int f1; double f2; };
3711 # struct example variable;
3714 If the user types TAB at the end of this command line, the available
3715 completions will be "f1" and "f2".
3717 * Inlined functions are now supported. They show up in backtraces, and
3718 the "step", "next", and "finish" commands handle them automatically.
3720 * GDB now supports the token-splicing (##) and stringification (#)
3721 operators when expanding macros. It also supports variable-arity
3724 * GDB now supports inspecting extra signal information, exported by
3725 the new $_siginfo convenience variable. The feature is currently
3726 implemented on linux ARM, i386 and amd64.
3728 * GDB can now display the VFP floating point registers and NEON vector
3729 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3730 can provide these registers (requires Linux 2.6.30 or later). Remote
3731 and simulator targets may also provide them.
3733 * New remote packets
3736 Search memory for a sequence of bytes.
3739 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3740 operation over reliable transport links. Use of this packet is
3741 controlled by the `set remote noack-packet' command.
3744 Kill the process with the specified process ID. Use this in preference
3745 to `k' when multiprocess protocol extensions are supported.
3748 Obtains additional operating system information
3752 Read or write additional signal information.
3754 * Removed remote protocol undocumented extension
3756 An undocumented extension to the remote protocol's `S' stop reply
3757 packet that permited the stub to pass a process id was removed.
3758 Remote servers should use the `T' stop reply packet instead.
3760 * GDB now supports multiple function calling conventions according to the
3761 DWARF-2 DW_AT_calling_convention function attribute.
3763 * The SH target utilizes the aforementioned change to distinguish between gcc
3764 and Renesas calling convention. It also adds the new CLI commands
3765 `set/show sh calling-convention'.
3767 * GDB can now read compressed debug sections, as produced by GNU gold
3768 with the --compress-debug-sections=zlib flag.
3770 * 64-bit core files are now supported on AIX.
3772 * Thread switching is now supported on Tru64.
3774 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3775 which will be allocated using malloc later in program execution.
3777 * The qXfer:libraries:read remote procotol packet now allows passing a
3778 list of section offsets.
3780 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3781 conditions handling signals delivered during attach or thread creation
3782 have also been fixed.
3784 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3785 From the user's standpoint, all unqualified instances of True and False
3786 are treated as the standard definitions, regardless of context.
3788 * GDB now parses C++ symbol and type names more flexibly. For
3791 template<typename T> class C { };
3794 GDB will now correctly handle all of:
3796 ptype C<char const *>
3797 ptype C<char const*>
3798 ptype C<const char *>
3799 ptype C<const char*>
3801 * New features in the GDB remote stub, gdbserver
3803 - The "--wrapper" command-line argument tells gdbserver to use a
3804 wrapper program to launch programs for debugging.
3806 - On PowerPC and S/390 targets, it is now possible to use a single
3807 gdbserver executable to debug both 32-bit and 64-bit programs.
3808 (This requires gdbserver itself to be built as a 64-bit executable.)
3810 - gdbserver uses the new noack protocol mode for TCP connections to
3811 reduce communications latency, if also supported and enabled in GDB.
3813 - Support for the sparc64-linux-gnu target is now included in
3816 - The amd64-linux build of gdbserver now supports debugging both
3817 32-bit and 64-bit programs.
3819 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3820 now support hardware watchpoints, and will use them automatically
3825 GDB now has support for scripting using Python. Whether this is
3826 available is determined at configure time.
3828 New GDB commands can now be written in Python.
3830 * Ada tasking support
3832 Ada tasks can now be inspected in GDB. The following commands have
3836 Print the list of Ada tasks.
3838 Print detailed information about task number N.
3840 Print the task number of the current task.
3842 Switch the context of debugging to task number N.
3844 * Support for user-defined prefixed commands. The "define" command can
3845 add new commands to existing prefixes, e.g. "target".
3847 * Multi-inferior, multi-process debugging.
3849 GDB now has generalized support for multi-inferior debugging. See
3850 "Debugging Multiple Inferiors" in the manual for more information.
3851 Although availability still depends on target support, the command
3852 set is more uniform now. The GNU/Linux specific multi-forks support
3853 has been migrated to this new framework. This implied some user
3854 visible changes; see "New commands" and also "Removed commands"
3857 * Target descriptions can now describe the target OS ABI. See the
3858 "Target Description Format" section in the user manual for more
3861 * Target descriptions can now describe "compatible" architectures
3862 to indicate that the target can execute applications for a different
3863 architecture in addition to those for the main target architecture.
3864 See the "Target Description Format" section in the user manual for
3867 * Multi-architecture debugging.
3869 GDB now includes general supports for debugging applications on
3870 hybrid systems that use more than one single processor architecture
3871 at the same time. Each such hybrid architecture still requires
3872 specific support to be added. The only hybrid architecture supported
3873 in this version of GDB is the Cell Broadband Engine.
3875 * GDB now supports integrated debugging of Cell/B.E. applications that
3876 use both the PPU and SPU architectures. To enable support for hybrid
3877 Cell/B.E. debugging, you need to configure GDB to support both the
3878 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3879 --enable-targets configure option.
3881 * Non-stop mode debugging.
3883 For some targets, GDB now supports an optional mode of operation in
3884 which you can examine stopped threads while other threads continue
3885 to execute freely. This is referred to as non-stop mode, with the
3886 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3887 section in the user manual for more information.
3889 To be able to support remote non-stop debugging, a remote stub needs
3890 to implement the non-stop mode remote protocol extensions, as
3891 described in the "Remote Non-Stop" section of the user manual. The
3892 GDB remote stub, gdbserver, has been adjusted to support these
3893 extensions on linux targets.
3895 * New commands (for set/show, see "New options" below)
3897 catch syscall [NAME(S) | NUMBER(S)]
3898 Catch system calls. Arguments, which should be names of system
3899 calls or their numbers, mean catch only those syscalls. Without
3900 arguments, every syscall will be caught. When the inferior issues
3901 any of the specified syscalls, GDB will stop and announce the system
3902 call, both when it is called and when its call returns. This
3903 feature is currently available with a native GDB running on the
3904 Linux Kernel, under the following architectures: x86, x86_64,
3905 PowerPC and PowerPC64.
3907 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3909 Search memory for a sequence of bytes.
3911 maint set python print-stack
3912 maint show python print-stack
3913 Show a stack trace when an error is encountered in a Python script.
3916 Invoke CODE by passing it to the Python interpreter.
3921 These allow macros to be defined, undefined, and listed
3925 Show operating system information about processes.
3928 List the inferiors currently under GDB's control.
3931 Switch focus to inferior number NUM.
3934 Detach from inferior number NUM.
3937 Kill inferior number NUM.
3941 set spu stop-on-load
3942 show spu stop-on-load
3943 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3945 set spu auto-flush-cache
3946 show spu auto-flush-cache
3947 Control whether to automatically flush the software-managed cache
3948 during Cell/B.E. debugging.
3950 set sh calling-convention
3951 show sh calling-convention
3952 Control the calling convention used when calling SH target functions.
3955 show debug timestamp
3956 Control display of timestamps with GDB debugging output.
3958 set disassemble-next-line
3959 show disassemble-next-line
3960 Control display of disassembled source lines or instructions when
3963 set remote noack-packet
3964 show remote noack-packet
3965 Set/show the use of remote protocol QStartNoAckMode packet. See above
3966 under "New remote packets."
3968 set remote query-attached-packet
3969 show remote query-attached-packet
3970 Control use of remote protocol `qAttached' (query-attached) packet.
3972 set remote read-siginfo-object
3973 show remote read-siginfo-object
3974 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3977 set remote write-siginfo-object
3978 show remote write-siginfo-object
3979 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3982 set remote reverse-continue
3983 show remote reverse-continue
3984 Control use of remote protocol 'bc' (reverse-continue) packet.
3986 set remote reverse-step
3987 show remote reverse-step
3988 Control use of remote protocol 'bs' (reverse-step) packet.
3990 set displaced-stepping
3991 show displaced-stepping
3992 Control displaced stepping mode. Displaced stepping is a way to
3993 single-step over breakpoints without removing them from the debuggee.
3994 Also known as "out-of-line single-stepping".
3997 show debug displaced
3998 Control display of debugging info for displaced stepping.
4000 maint set internal-error
4001 maint show internal-error
4002 Control what GDB does when an internal error is detected.
4004 maint set internal-warning
4005 maint show internal-warning
4006 Control what GDB does when an internal warning is detected.
4011 Use a wrapper program to launch programs for debugging.
4013 set multiple-symbols (all|ask|cancel)
4014 show multiple-symbols
4015 The value of this variable can be changed to adjust the debugger behavior
4016 when an expression or a breakpoint location contains an ambiguous symbol
4017 name (an overloaded function name, for instance).
4019 set breakpoint always-inserted
4020 show breakpoint always-inserted
4021 Keep breakpoints always inserted in the target, as opposed to inserting
4022 them when resuming the target, and removing them when the target stops.
4023 This option can improve debugger performance on slow remote targets.
4025 set arm fallback-mode (arm|thumb|auto)
4026 show arm fallback-mode
4027 set arm force-mode (arm|thumb|auto)
4029 These commands control how ARM GDB determines whether instructions
4030 are ARM or Thumb. The default for both settings is auto, which uses
4031 the current CPSR value for instructions without symbols; previous
4032 versions of GDB behaved as if "set arm fallback-mode arm".
4034 set disable-randomization
4035 show disable-randomization
4036 Standalone programs run with the virtual address space randomization enabled
4037 by default on some platforms. This option keeps the addresses stable across
4038 multiple debugging sessions.
4042 Control whether other threads are stopped or not when some thread hits
4047 Requests that asynchronous execution is enabled in the target, if available.
4048 In this case, it's possible to resume target in the background, and interact
4049 with GDB while the target is running. "show target-async" displays the
4050 current state of asynchronous execution of the target.
4052 set target-wide-charset
4053 show target-wide-charset
4054 The target-wide-charset is the name of the character set that GDB
4055 uses when printing characters whose type is wchar_t.
4057 set tcp auto-retry (on|off)
4059 set tcp connect-timeout
4060 show tcp connect-timeout
4061 These commands allow GDB to retry failed TCP connections to a remote stub
4062 with a specified timeout period; this is useful if the stub is launched
4063 in parallel with GDB but may not be ready to accept connections immediately.
4065 set libthread-db-search-path
4066 show libthread-db-search-path
4067 Control list of directories which GDB will search for appropriate
4070 set schedule-multiple (on|off)
4071 show schedule-multiple
4072 Allow GDB to resume all threads of all processes or only threads of
4073 the current process.
4077 Use more aggressive caching for accesses to the stack. This improves
4078 performance of remote debugging (particularly backtraces) without
4079 affecting correctness.
4081 set interactive-mode (on|off|auto)
4082 show interactive-mode
4083 Control whether GDB runs in interactive mode (on) or not (off).
4084 When in interactive mode, GDB waits for the user to answer all
4085 queries. Otherwise, GDB does not wait and assumes the default
4086 answer. When set to auto (the default), GDB determines which
4087 mode to use based on the stdin settings.
4092 For program forks, this is replaced by the new more generic `info
4093 inferiors' command. To list checkpoints, you can still use the
4094 `info checkpoints' command, which was an alias for the `info forks'
4098 Replaced by the new `inferior' command. To switch between
4099 checkpoints, you can still use the `restart' command, which was an
4100 alias for the `fork' command.
4103 This is removed, since some targets don't have a notion of
4104 processes. To switch between processes, you can still use the
4105 `inferior' command using GDB's own inferior number.
4108 For program forks, this is replaced by the new more generic `kill
4109 inferior' command. To delete a checkpoint, you can still use the
4110 `delete checkpoint' command, which was an alias for the `delete
4114 For program forks, this is replaced by the new more generic `detach
4115 inferior' command. To detach a checkpoint, you can still use the
4116 `detach checkpoint' command, which was an alias for the `detach
4119 * New native configurations
4121 x86/x86_64 Darwin i[34567]86-*-darwin*
4123 x86_64 MinGW x86_64-*-mingw*
4127 Lattice Mico32 lm32-*
4128 x86 DICOS i[34567]86-*-dicos*
4129 x86_64 DICOS x86_64-*-dicos*
4132 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4133 (mingw32ce) debugging.
4139 These commands were actually not implemented on any target.
4141 *** Changes in GDB 6.8
4143 * New native configurations
4145 NetBSD/hppa hppa*-*netbsd*
4146 Xtensa GNU/Linux xtensa*-*-linux*
4150 NetBSD/hppa hppa*-*-netbsd*
4151 Xtensa GNU/Lunux xtensa*-*-linux*
4153 * Change in command line behavior -- corefiles vs. process ids.
4155 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4156 attaching to process NUMBER fails, GDB no longer attempts to open a
4157 core file named NUMBER. Attaching to a program using the -c option
4158 is no longer supported. Instead, use the '-p' or '--pid' options.
4160 * GDB can now be built as a native debugger for debugging Windows x86
4161 (mingw32) Portable Executable (PE) programs.
4163 * Pending breakpoints no longer change their number when their address
4166 * GDB now supports breakpoints with multiple locations,
4167 including breakpoints on C++ constructors, inside C++ templates,
4168 and in inlined functions.
4170 * GDB's ability to debug optimized code has been improved. GDB more
4171 accurately identifies function bodies and lexical blocks that occupy
4172 more than one contiguous range of addresses.
4174 * Target descriptions can now describe registers for PowerPC.
4176 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4177 registers on PowerPC targets.
4179 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4180 targets even when the libthread_db library is not available.
4182 * The GDB remote stub, gdbserver, now supports the new file transfer
4183 commands (remote put, remote get, and remote delete).
4185 * The GDB remote stub, gdbserver, now supports run and attach in
4186 extended-remote mode.
4188 * hppa*64*-*-hpux11* target broken
4189 The debugger is unable to start a program and fails with the following
4190 error: "Error trying to get information about dynamic linker".
4191 The gdb-6.7 release is also affected.
4193 * GDB now supports the --enable-targets= configure option to allow
4194 building a single GDB executable that supports multiple remote
4195 target architectures.
4197 * GDB now supports debugging C and C++ programs which use the
4198 Decimal Floating Point extension. In addition, the PowerPC target
4199 now has a set of pseudo-registers to inspect decimal float values
4200 stored in two consecutive float registers.
4202 * The -break-insert MI command can optionally create pending
4205 * Improved support for debugging Ada
4206 Many improvements to the Ada language support have been made. These
4208 - Better support for Ada2005 interface types
4209 - Improved handling of arrays and slices in general
4210 - Better support for Taft-amendment types
4211 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4213 - Improved command completion in Ada
4216 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4221 set print frame-arguments (all|scalars|none)
4222 show print frame-arguments
4223 The value of this variable can be changed to control which argument
4224 values should be printed by the debugger when displaying a frame.
4229 Transfer files to and from a remote target, and delete remote files.
4236 Transfer files to and from a remote target, and delete remote files.
4238 * New remote packets
4245 Open, close, read, write, and delete files on the remote system.
4248 Attach to an existing process on the remote system, in extended-remote
4252 Run a new process on the remote system, in extended-remote mode.
4254 *** Changes in GDB 6.7
4256 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4257 bfd, libiberty and opcodes, as revealed by static analysis donated by
4258 Coverity, Inc. (http://scan.coverity.com).
4260 * When looking up multiply-defined global symbols, GDB will now prefer the
4261 symbol definition in the current shared library if it was built using the
4262 -Bsymbolic linker option.
4264 * When the Text User Interface (TUI) is not configured, GDB will now
4265 recognize the -tui command-line option and print a message that the TUI
4268 * The GDB remote stub, gdbserver, now has lower overhead for high
4269 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4271 * GDB for MIPS targets now autodetects whether a remote target provides
4272 32-bit or 64-bit register values.
4274 * Support for C++ member pointers has been improved.
4276 * GDB now understands XML target descriptions, which specify the
4277 target's overall architecture. GDB can read a description from
4278 a local file or over the remote serial protocol.
4280 * Vectors of single-byte data use a new integer type which is not
4281 automatically displayed as character or string data.
4283 * The /s format now works with the print command. It displays
4284 arrays of single-byte integers and pointers to single-byte integers
4287 * Target descriptions can now describe target-specific registers,
4288 for architectures which have implemented the support (currently
4289 only ARM, M68K, and MIPS).
4291 * GDB and the GDB remote stub, gdbserver, now support the XScale
4294 * The GDB remote stub, gdbserver, has been updated to support
4295 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4296 has been rewritten to use the standard GDB remote protocol.
4298 * GDB can now step into C++ functions which are called through thunks.
4300 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4302 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4303 layout. It also supports a TextSeg= and DataSeg= response when only
4304 segment base addresses (rather than offsets) are available.
4306 * The /i format now outputs any trailing branch delay slot instructions
4307 immediately following the last instruction within the count specified.
4309 * The GDB remote protocol "T" stop reply packet now supports a
4310 "library" response. Combined with the new "qXfer:libraries:read"
4311 packet, this response allows GDB to debug shared libraries on targets
4312 where the operating system manages the list of loaded libraries (e.g.
4313 Windows and SymbianOS).
4315 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4316 (DLLs) on Windows and Windows CE targets.
4318 * GDB now supports a faster verification that a .debug file matches its binary
4319 according to its build-id signature, if the signature is present.
4325 Enable or disable hardware flow control (RTS/CTS) on the serial port
4326 when debugging using remote targets.
4328 set mem inaccessible-by-default
4329 show mem inaccessible-by-default
4330 If the target supplies a memory map, for instance via the remote
4331 protocol's "qXfer:memory-map:read" packet, setting this variable
4332 prevents GDB from accessing memory outside the memory map. This
4333 is useful for targets with memory mapped registers or which react
4334 badly to accesses of unmapped address space.
4336 set breakpoint auto-hw
4337 show breakpoint auto-hw
4338 If the target supplies a memory map, for instance via the remote
4339 protocol's "qXfer:memory-map:read" packet, setting this variable
4340 lets GDB use hardware breakpoints automatically for memory regions
4341 where it can not use software breakpoints. This covers both the
4342 "break" command and internal breakpoints used for other commands
4343 including "next" and "finish".
4346 catch exception unhandled
4347 Stop the program execution when Ada exceptions are raised.
4350 Stop the program execution when an Ada assertion failed.
4354 Set an alternate system root for target files. This is a more
4355 general version of "set solib-absolute-prefix", which is now
4356 an alias to "set sysroot".
4359 Provide extended SPU facility status information. This set of
4360 commands is available only when debugging the Cell/B.E. SPU
4363 * New native configurations
4365 OpenBSD/sh sh*-*openbsd*
4368 unset tdesc filename
4370 Use the specified local file as an XML target description, and do
4371 not query the target for its built-in description.
4375 OpenBSD/sh sh*-*-openbsd*
4376 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4377 Toshiba Media Processor mep-elf
4379 * New remote packets
4382 Ignore the specified signals; pass them directly to the debugged program
4383 without stopping other threads or reporting them to GDB.
4385 qXfer:features:read:
4386 Read an XML target description from the target, which describes its
4391 Read or write contents of an spufs file on the target system. These
4392 packets are available only on the Cell/B.E. SPU architecture.
4394 qXfer:libraries:read:
4395 Report the loaded shared libraries. Combined with new "T" packet
4396 response, this packet allows GDB to debug shared libraries on
4397 targets where the operating system manages the list of loaded
4398 libraries (e.g. Windows and SymbianOS).
4402 Support for these obsolete configurations has been removed.
4410 i[34567]86-*-lynxos*
4411 i[34567]86-*-netware*
4412 i[34567]86-*-sco3.2v5*
4413 i[34567]86-*-sco3.2v4*
4415 i[34567]86-*-sysv4.2*
4418 i[34567]86-*-unixware2*
4419 i[34567]86-*-unixware*
4428 * Other removed features
4435 Various m68k-only ROM monitors.
4442 Various Renesas ROM monitors and debugging interfaces for SH and
4447 Support for a Macraigor serial interface to on-chip debugging.
4448 GDB does not directly support the newer parallel or USB
4453 A debug information format. The predecessor to DWARF 2 and
4454 DWARF 3, which are still supported.
4456 Support for the HP aCC compiler on HP-UX/PA-RISC
4458 SOM-encapsulated symbolic debugging information, automatic
4459 invocation of pxdb, and the aCC custom C++ ABI. This does not
4460 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4461 with aCC can still be debugged on an assembly level.
4463 MIPS ".pdr" sections
4465 A MIPS-specific format used to describe stack frame layout
4466 in debugging information.
4470 GDB could work with an older version of Guile to debug
4471 the interpreter and Scheme programs running in it.
4473 set mips stack-arg-size
4474 set mips saved-gpreg-size
4476 Use "set mips abi" to control parameter passing for MIPS.
4478 *** Changes in GDB 6.6
4483 Cell Broadband Engine SPU spu-elf
4485 * GDB can now be configured as a cross-debugger targeting native Windows
4486 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4487 running on a Windows system over TCP/IP to debug Windows programs.
4489 * The GDB remote stub, gdbserver, has been updated to support Windows and
4490 Cygwin debugging. Both single-threaded and multi-threaded programs are
4493 * The "set trust-readonly-sections" command works again. This command was
4494 broken in GDB 6.3, 6.4, and 6.5.
4496 * The "load" command now supports writing to flash memory, if the remote
4497 stub provides the required support.
4499 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4500 longer requires symbolic debug information (e.g. DWARF-2).
4505 unset substitute-path
4506 show substitute-path
4507 Manage a list of substitution rules that GDB uses to rewrite the name
4508 of the directories where the sources are located. This can be useful
4509 for instance when the sources were moved to a different location
4510 between compilation and debugging.
4514 Print each CLI command as it is executed. Each command is prefixed with
4515 a number of `+' symbols representing the nesting depth.
4516 The source command now has a `-v' option to enable the same feature.
4520 The ARM Demon monitor support (RDP protocol, "target rdp").
4522 Kernel Object Display, an embedded debugging feature which only worked with
4523 an obsolete version of Cisco IOS.
4525 The 'set download-write-size' and 'show download-write-size' commands.
4527 * New remote packets
4530 Tell a stub about GDB client features, and request remote target features.
4531 The first feature implemented is PacketSize, which allows the target to
4532 specify the size of packets it can handle - to minimize the number of
4533 packets required and improve performance when connected to a remote
4537 Fetch an OS auxilliary vector from the remote stub. This packet is a
4538 more efficient replacement for qPart:auxv:read.
4540 qXfer:memory-map:read:
4541 Fetch a memory map from the remote stub, including information about
4542 RAM, ROM, and flash memory devices.
4547 Erase and program a flash memory device.
4549 * Removed remote packets
4552 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4553 used it, and only gdbserver implemented it.
4555 *** Changes in GDB 6.5
4559 Renesas M32C/M16C m32c-elf
4561 Morpho Technologies ms1 ms1-elf
4565 init-if-undefined Initialize a convenience variable, but
4566 only if it doesn't already have a value.
4568 The following commands are presently only implemented for native GNU/Linux:
4570 checkpoint Save a snapshot of the program state.
4572 restart <n> Return the program state to a
4573 previously saved state.
4575 info checkpoints List currently saved checkpoints.
4577 delete-checkpoint <n> Delete a previously saved checkpoint.
4579 set|show detach-on-fork Tell gdb whether to detach from a newly
4580 forked process, or to keep debugging it.
4582 info forks List forks of the user program that
4583 are available to be debugged.
4585 fork <n> Switch to debugging one of several
4586 forks of the user program that are
4587 available to be debugged.
4589 delete-fork <n> Delete a fork from the list of forks
4590 that are available to be debugged (and
4591 kill the forked process).
4593 detach-fork <n> Delete a fork from the list of forks
4594 that are available to be debugged (and
4595 allow the process to continue).
4599 Morpho Technologies ms2 ms1-elf
4601 * Improved Windows host support
4603 GDB now builds as a cross debugger hosted on i686-mingw32, including
4604 native console support, and remote communications using either
4605 network sockets or serial ports.
4607 * Improved Modula-2 language support
4609 GDB can now print most types in the Modula-2 syntax. This includes:
4610 basic types, set types, record types, enumerated types, range types,
4611 pointer types and ARRAY types. Procedure var parameters are correctly
4612 printed and hexadecimal addresses and character constants are also
4613 written in the Modula-2 syntax. Best results can be obtained by using
4614 GNU Modula-2 together with the -gdwarf-2 command line option.
4618 The ARM rdi-share module.
4620 The Netware NLM debug server.
4622 *** Changes in GDB 6.4
4624 * New native configurations
4626 OpenBSD/arm arm*-*-openbsd*
4627 OpenBSD/mips64 mips64-*-openbsd*
4631 Morpho Technologies ms1 ms1-elf
4633 * New command line options
4635 --batch-silent As for --batch, but totally silent.
4636 --return-child-result The debugger will exist with the same value
4637 the child (debugged) program exited with.
4638 --eval-command COMMAND, -ex COMMAND
4639 Execute a single GDB CLI command. This may be
4640 specified multiple times and in conjunction
4641 with the --command (-x) option.
4643 * Deprecated commands removed
4645 The following commands, that were deprecated in 2000, have been
4649 set|show arm disassembly-flavor set|show arm disassembler
4650 othernames set arm disassembler
4651 set|show remotedebug set|show debug remote
4652 set|show archdebug set|show debug arch
4653 set|show eventdebug set|show debug event
4656 * New BSD user-level threads support
4658 It is now possible to debug programs using the user-level threads
4659 library on OpenBSD and FreeBSD. Currently supported (target)
4662 FreeBSD/amd64 x86_64-*-freebsd*
4663 FreeBSD/i386 i386-*-freebsd*
4664 OpenBSD/i386 i386-*-openbsd*
4666 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4667 are not yet supported.
4669 * New support for Matsushita MN10300 w/sim added
4670 (Work in progress). mn10300-elf.
4672 * REMOVED configurations and files
4674 VxWorks and the XDR protocol *-*-vxworks
4675 Motorola MCORE mcore-*-*
4676 National Semiconductor NS32000 ns32k-*-*
4678 * New "set print array-indexes" command
4680 After turning this setting "on", GDB prints the index of each element
4681 when displaying arrays. The default is "off" to preserve the previous
4684 * VAX floating point support
4686 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4688 * User-defined command support
4690 In addition to using $arg0..$arg9 for argument passing, it is now possible
4691 to use $argc to determine now many arguments have been passed. See the
4692 section on user-defined commands in the user manual for more information.
4694 *** Changes in GDB 6.3:
4696 * New command line option
4698 GDB now accepts -l followed by a number to set the timeout for remote
4701 * GDB works with GCC -feliminate-dwarf2-dups
4703 GDB now supports a more compact representation of DWARF-2 debug
4704 information using DW_FORM_ref_addr references. These are produced
4705 by GCC with the option -feliminate-dwarf2-dups and also by some
4706 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4707 to use -feliminate-dwarf2-dups.
4709 * Internationalization
4711 When supported by the host system, GDB will be built with
4712 internationalization (libintl). The task of marking up the sources is
4713 continued, we're looking forward to our first translation.
4717 Initial support for debugging programs compiled with the GNAT
4718 implementation of the Ada programming language has been integrated
4719 into GDB. In this release, support is limited to expression evaluation.
4721 * New native configurations
4723 GNU/Linux/m32r m32r-*-linux-gnu
4727 GDB's remote protocol now includes support for the 'p' packet. This
4728 packet is used to fetch individual registers from a remote inferior.
4730 * END-OF-LIFE registers[] compatibility module
4732 GDB's internal register infrastructure has been completely rewritten.
4733 The new infrastructure making possible the implementation of key new
4734 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4737 GDB 6.3 will be the last release to include the the registers[]
4738 compatibility module that allowed out-of-date configurations to
4739 continue to work. This change directly impacts the following
4749 powerpc bdm protocol
4751 Unless there is activity to revive these configurations, they will be
4752 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4754 * OBSOLETE configurations and files
4756 Configurations that have been declared obsolete in this release have
4757 been commented out. Unless there is activity to revive these
4758 configurations, the next release of GDB will have their sources
4759 permanently REMOVED.
4768 *** Changes in GDB 6.2.1:
4770 * MIPS `break main; run' gave an heuristic-fence-post warning
4772 When attempting to run even a simple program, a warning about
4773 heuristic-fence-post being hit would be reported. This problem has
4776 * MIPS IRIX 'long double' crashed GDB
4778 When examining a long double variable, GDB would get a segmentation
4779 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4780 IRIX long double values).
4784 A bug in the VAX stack code was causing problems with the "next"
4785 command. This problem has been fixed.
4787 *** Changes in GDB 6.2:
4789 * Fix for ``many threads''
4791 On GNU/Linux systems that use the NPTL threads library, a program
4792 rapidly creating and deleting threads would confuse GDB leading to the
4795 ptrace: No such process.
4796 thread_db_get_info: cannot get thread info: generic error
4798 This problem has been fixed.
4800 * "-async" and "-noasync" options removed.
4802 Support for the broken "-noasync" option has been removed (it caused
4805 * New ``start'' command.
4807 This command runs the program until the begining of the main procedure.
4809 * New BSD Kernel Data Access Library (libkvm) interface
4811 Using ``target kvm'' it is now possible to debug kernel core dumps and
4812 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4813 platforms. Currently supported (native-only) configurations are:
4815 FreeBSD/amd64 x86_64-*-freebsd*
4816 FreeBSD/i386 i?86-*-freebsd*
4817 NetBSD/i386 i?86-*-netbsd*
4818 NetBSD/m68k m68*-*-netbsd*
4819 NetBSD/sparc sparc-*-netbsd*
4820 OpenBSD/amd64 x86_64-*-openbsd*
4821 OpenBSD/i386 i?86-*-openbsd*
4822 OpenBSD/m68k m68*-openbsd*
4823 OpenBSD/sparc sparc-*-openbsd*
4825 * Signal trampoline code overhauled
4827 Many generic problems with GDB's signal handling code have been fixed.
4828 These include: backtraces through non-contiguous stacks; recognition
4829 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4830 call; backtrace through a signal trampoline; step into and out of
4831 signal handlers; and single-stepping in the signal trampoline.
4833 Please note that kernel bugs are a limiting factor here. These
4834 features have been shown to work on an s390 GNU/Linux system that
4835 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4837 * Cygwin support for DWARF 2 added.
4839 * New native configurations
4841 GNU/Linux/hppa hppa*-*-linux*
4842 OpenBSD/hppa hppa*-*-openbsd*
4843 OpenBSD/m68k m68*-*-openbsd*
4844 OpenBSD/m88k m88*-*-openbsd*
4845 OpenBSD/powerpc powerpc-*-openbsd*
4846 NetBSD/vax vax-*-netbsd*
4847 OpenBSD/vax vax-*-openbsd*
4849 * END-OF-LIFE frame compatibility module
4851 GDB's internal frame infrastructure has been completely rewritten.
4852 The new infrastructure making it possible to support key new features
4853 including DWARF 2 Call Frame Information. To aid in the task of
4854 migrating old configurations to this new infrastructure, a
4855 compatibility module, that allowed old configurations to continue to
4856 work, was also included.
4858 GDB 6.2 will be the last release to include this frame compatibility
4859 module. This change directly impacts the following configurations:
4869 Unless there is activity to revive these configurations, they will be
4870 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4872 * REMOVED configurations and files
4874 Sun 3, running SunOS 3 m68*-*-sunos3*
4875 Sun 3, running SunOS 4 m68*-*-sunos4*
4876 Sun 2, running SunOS 3 m68000-*-sunos3*
4877 Sun 2, running SunOS 4 m68000-*-sunos4*
4878 Motorola 680x0 running LynxOS m68*-*-lynxos*
4879 AT&T 3b1/Unix pc m68*-att-*
4880 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4881 decstation mips-dec-* mips-little-*
4882 riscos mips-*-riscos* mips-*-sysv*
4883 sonymips mips-sony-*
4884 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4886 *** Changes in GDB 6.1.1:
4888 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4890 The TUI (Text-mode User Interface) is now built as part of a default
4891 GDB configuration. It is enabled by either selecting the TUI with the
4892 command line option "-i=tui" or by running the separate "gdbtui"
4893 program. For more information on the TUI, see the manual "Debugging
4896 * Pending breakpoint support (also included in GDB 6.1)
4898 Support has been added to allow you to specify breakpoints in shared
4899 libraries that have not yet been loaded. If a breakpoint location
4900 cannot be found, and the "breakpoint pending" option is set to auto,
4901 GDB queries you if you wish to make the breakpoint pending on a future
4902 shared-library load. If and when GDB resolves the breakpoint symbol,
4903 the pending breakpoint is removed as one or more regular breakpoints
4906 Pending breakpoints are very useful for GCJ Java debugging.
4908 * Fixed ISO-C build problems
4910 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4911 non ISO-C code that stopped them being built using a more strict ISO-C
4912 compiler (e.g., IBM's C compiler).
4914 * Fixed build problem on IRIX 5
4916 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4917 wasn't able to compile compile on an IRIX 5 system.
4919 * Added execute permission to gdb/gdbserver/configure
4921 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4922 permission. This bug would cause configure to fail on a number of
4923 systems (Solaris, IRIX). Ref: server/519.
4925 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4927 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4928 has been updated to use constant array sizes.
4930 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4932 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4933 its generated DWARF Call Frame Info. This encoding was causing GDB to
4934 panic, that panic has been fixed. Ref: gdb/1628.
4936 * Fixed a problem when examining parameters in shared library code.
4938 When examining parameters in optimized shared library code generated
4939 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4940 not available''. GDB now correctly displays the variable's value.
4942 *** Changes in GDB 6.1:
4944 * Removed --with-mmalloc
4946 Support for the mmalloc memory manager has been removed, as it
4947 conflicted with the internal gdb byte cache.
4949 * Changes in AMD64 configurations
4951 The AMD64 target now includes the %cs and %ss registers. As a result
4952 the AMD64 remote protocol has changed; this affects the floating-point
4953 and SSE registers. If you rely on those registers for your debugging,
4954 you should upgrade gdbserver on the remote side.
4956 * Revised SPARC target
4958 The SPARC target has been completely revised, incorporating the
4959 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4960 support for LynxOS and SunOS 4 has been dropped. Calling functions
4961 from within GDB on operating systems with a non-executable stack
4962 (Solaris, OpenBSD) now works.
4966 GDB has a new C++ demangler which does a better job on the mangled
4967 names generated by current versions of g++. It also runs faster, so
4968 with this and other changes gdb should now start faster on large C++
4971 * DWARF 2 Location Expressions
4973 GDB support for location expressions has been extended to support function
4974 arguments and frame bases. Older versions of GDB could crash when they
4977 * C++ nested types and namespaces
4979 GDB's support for nested types and namespaces in C++ has been
4980 improved, especially if you use the DWARF 2 debugging format. (This
4981 is the default for recent versions of GCC on most platforms.)
4982 Specifically, if you have a class "Inner" defined within a class or
4983 namespace "Outer", then GDB realizes that the class's name is
4984 "Outer::Inner", not simply "Inner". This should greatly reduce the
4985 frequency of complaints about not finding RTTI symbols. In addition,
4986 if you are stopped at inside of a function defined within a namespace,
4987 GDB modifies its name lookup accordingly.
4989 * New native configurations
4991 NetBSD/amd64 x86_64-*-netbsd*
4992 OpenBSD/amd64 x86_64-*-openbsd*
4993 OpenBSD/alpha alpha*-*-openbsd*
4994 OpenBSD/sparc sparc-*-openbsd*
4995 OpenBSD/sparc64 sparc64-*-openbsd*
4997 * New debugging protocols
4999 M32R with SDI protocol m32r-*-elf*
5001 * "set prompt-escape-char" command deleted.
5003 The command "set prompt-escape-char" has been deleted. This command,
5004 and its very obscure effet on GDB's prompt, was never documented,
5005 tested, nor mentioned in the NEWS file.
5007 * OBSOLETE configurations and files
5009 Configurations that have been declared obsolete in this release have
5010 been commented out. Unless there is activity to revive these
5011 configurations, the next release of GDB will have their sources
5012 permanently REMOVED.
5014 Sun 3, running SunOS 3 m68*-*-sunos3*
5015 Sun 3, running SunOS 4 m68*-*-sunos4*
5016 Sun 2, running SunOS 3 m68000-*-sunos3*
5017 Sun 2, running SunOS 4 m68000-*-sunos4*
5018 Motorola 680x0 running LynxOS m68*-*-lynxos*
5019 AT&T 3b1/Unix pc m68*-att-*
5020 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5021 decstation mips-dec-* mips-little-*
5022 riscos mips-*-riscos* mips-*-sysv*
5023 sonymips mips-sony-*
5024 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5026 * REMOVED configurations and files
5028 SGI Irix-4.x mips-sgi-irix4 or iris4
5029 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5030 Z8000 simulator z8k-zilog-none or z8ksim
5031 Matsushita MN10200 w/simulator mn10200-*-*
5032 H8/500 simulator h8500-hitachi-hms or h8500hms
5033 HP/PA running BSD hppa*-*-bsd*
5034 HP/PA running OSF/1 hppa*-*-osf*
5035 HP/PA Pro target hppa*-*-pro*
5036 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5037 386BSD i[3456]86-*-bsd*
5038 Sequent family i[3456]86-sequent-sysv4*
5039 i[3456]86-sequent-sysv*
5040 i[3456]86-sequent-bsd*
5041 SPARC running LynxOS sparc-*-lynxos*
5042 SPARC running SunOS 4 sparc-*-sunos4*
5043 Tsqware Sparclet sparclet-*-*
5044 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5046 *** Changes in GDB 6.0:
5050 Support for debugging the Objective-C programming language has been
5051 integrated into GDB.
5053 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5055 DWARF 2's Call Frame Information makes available compiler generated
5056 information that more exactly describes the program's run-time stack.
5057 By using this information, GDB is able to provide more robust stack
5060 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5061 have been updated to use a new backtrace mechanism which includes
5062 DWARF 2 CFI support.
5066 GDB's remote protocol has been extended to include support for hosted
5067 file I/O (where the remote target uses GDB's file system). See GDB's
5068 remote protocol documentation for details.
5070 * All targets using the new architecture framework.
5072 All of GDB's targets have been updated to use the new internal
5073 architecture framework. The way is now open for future GDB releases
5074 to include cross-architecture native debugging support (i386 on amd64,
5077 * GNU/Linux's Thread Local Storage (TLS)
5079 GDB now includes support for for the GNU/Linux implementation of
5080 per-thread variables.
5082 * GNU/Linux's Native POSIX Thread Library (NPTL)
5084 GDB's thread code has been updated to work with either the new
5085 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5087 * Separate debug info.
5089 GDB, in conjunction with BINUTILS, now supports a mechanism for
5090 automatically loading debug information from a separate file. Instead
5091 of shipping full debug and non-debug versions of system libraries,
5092 system integrators can now instead ship just the stripped libraries
5093 and optional debug files.
5095 * DWARF 2 Location Expressions
5097 DWARF 2 Location Expressions allow the compiler to more completely
5098 describe the location of variables (even in optimized code) to the
5101 GDB now includes preliminary support for location expressions (support
5102 for DW_OP_piece is still missing).
5106 A number of long standing bugs that caused GDB to die while starting a
5107 Java application have been fixed. GDB's Java support is now
5108 considered "useable".
5110 * GNU/Linux support for fork, vfork, and exec.
5112 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5113 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5116 * GDB supports logging output to a file
5118 There are two new commands, "set logging" and "show logging", which can be
5119 used to capture GDB's output to a file.
5121 * The meaning of "detach" has changed for gdbserver
5123 The "detach" command will now resume the application, as documented. To
5124 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5127 * d10v, m68hc11 `regs' command deprecated
5129 The `info registers' command has been updated so that it displays the
5130 registers using a format identical to the old `regs' command.
5134 A new command, "maint set profile on/off", has been added. This command can
5135 be used to enable or disable profiling while running GDB, to profile a
5136 session or a set of commands. In addition there is a new configure switch,
5137 "--enable-profiling", which will cause GDB to be compiled with profiling
5138 data, for more informative profiling results.
5140 * Default MI syntax changed to "mi2".
5142 The default MI (machine interface) syntax, enabled by the command line
5143 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5144 "mi1", can be enabled by specifying the option "-i=mi1".
5146 Support for the original "mi0" syntax (included in GDB 5.0) has been
5149 Fix for gdb/192: removed extraneous space when displaying frame level.
5150 Fix for gdb/672: update changelist is now output in mi list format.
5151 Fix for gdb/702: a -var-assign that updates the value now shows up
5152 in a subsequent -var-update.
5154 * New native configurations.
5156 FreeBSD/amd64 x86_64-*-freebsd*
5158 * Multi-arched targets.
5160 HP/PA HPUX11 hppa*-*-hpux*
5161 Renesas M32R/D w/simulator m32r-*-elf*
5163 * OBSOLETE configurations and files
5165 Configurations that have been declared obsolete in this release have
5166 been commented out. Unless there is activity to revive these
5167 configurations, the next release of GDB will have their sources
5168 permanently REMOVED.
5170 Z8000 simulator z8k-zilog-none or z8ksim
5171 Matsushita MN10200 w/simulator mn10200-*-*
5172 H8/500 simulator h8500-hitachi-hms or h8500hms
5173 HP/PA running BSD hppa*-*-bsd*
5174 HP/PA running OSF/1 hppa*-*-osf*
5175 HP/PA Pro target hppa*-*-pro*
5176 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5177 Sequent family i[3456]86-sequent-sysv4*
5178 i[3456]86-sequent-sysv*
5179 i[3456]86-sequent-bsd*
5180 Tsqware Sparclet sparclet-*-*
5181 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5183 * REMOVED configurations and files
5186 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5187 IBM AIX PS/2 i[3456]86-*-aix
5188 i386 running Mach 3.0 i[3456]86-*-mach3*
5189 i386 running Mach i[3456]86-*-mach*
5190 i386 running OSF/1 i[3456]86-*osf1mk*
5191 HP/Apollo 68k Family m68*-apollo*-sysv*,
5193 m68*-hp-bsd*, m68*-hp-hpux*
5194 Argonaut Risc Chip (ARC) arc-*-*
5195 Mitsubishi D30V d30v-*-*
5196 Fujitsu FR30 fr30-*-elf*
5197 OS/9000 i[34]86-*-os9k
5198 I960 with MON960 i960-*-coff
5200 * MIPS $fp behavior changed
5202 The convenience variable $fp, for the MIPS, now consistently returns
5203 the address of the current frame's base. Previously, depending on the
5204 context, $fp could refer to either $sp or the current frame's base
5205 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5206 The GNU Source-Level Debugger''.
5208 *** Changes in GDB 5.3:
5210 * GNU/Linux shared library multi-threaded performance improved.
5212 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5213 `/proc', in preference to `ptrace' for memory reads. This may result
5214 in an improvement in the start-up time of multi-threaded, shared
5215 library applications when run under GDB. One GDB user writes: ``loads
5216 shared libs like mad''.
5218 * ``gdbserver'' now supports multi-threaded applications on some targets
5220 Support for debugging multi-threaded applications which use
5221 the GNU/Linux LinuxThreads package has been added for
5222 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5223 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5225 * GDB now supports C/C++ preprocessor macros.
5227 GDB now expands preprocessor macro invocations in C/C++ expressions,
5228 and provides various commands for showing macro definitions and how
5231 The new command `macro expand EXPRESSION' expands any macro
5232 invocations in expression, and shows the result.
5234 The new command `show macro MACRO-NAME' shows the definition of the
5235 macro named MACRO-NAME, and where it was defined.
5237 Most compilers don't include information about macros in the debugging
5238 information by default. In GCC 3.1, for example, you need to compile
5239 your program with the options `-gdwarf-2 -g3'. If the macro
5240 information is present in the executable, GDB will read it.
5242 * Multi-arched targets.
5244 DEC Alpha (partial) alpha*-*-*
5245 DEC VAX (partial) vax-*-*
5247 National Semiconductor NS32000 (partial) ns32k-*-*
5248 Motorola 68000 (partial) m68k-*-*
5249 Motorola MCORE mcore-*-*
5253 Fujitsu FRV architecture added by Red Hat frv*-*-*
5256 * New native configurations
5258 Alpha NetBSD alpha*-*-netbsd*
5259 SH NetBSD sh*-*-netbsdelf*
5260 MIPS NetBSD mips*-*-netbsd*
5261 UltraSPARC NetBSD sparc64-*-netbsd*
5263 * OBSOLETE configurations and files
5265 Configurations that have been declared obsolete in this release have
5266 been commented out. Unless there is activity to revive these
5267 configurations, the next release of GDB will have their sources
5268 permanently REMOVED.
5270 Mitsubishi D30V d30v-*-*
5271 OS/9000 i[34]86-*-os9k
5272 IBM AIX PS/2 i[3456]86-*-aix
5273 Fujitsu FR30 fr30-*-elf*
5274 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5275 Argonaut Risc Chip (ARC) arc-*-*
5276 i386 running Mach 3.0 i[3456]86-*-mach3*
5277 i386 running Mach i[3456]86-*-mach*
5278 i386 running OSF/1 i[3456]86-*osf1mk*
5279 HP/Apollo 68k Family m68*-apollo*-sysv*,
5281 m68*-hp-bsd*, m68*-hp-hpux*
5282 I960 with MON960 i960-*-coff
5284 * OBSOLETE languages
5286 CHILL, a Pascal like language used by telecommunications companies.
5288 * REMOVED configurations and files
5290 AMD 29k family via UDI a29k-amd-udi, udi29k
5291 A29K VxWorks a29k-*-vxworks
5292 AMD 29000 embedded, using EBMON a29k-none-none
5293 AMD 29000 embedded with COFF a29k-none-coff
5294 AMD 29000 embedded with a.out a29k-none-aout
5296 testsuite/gdb.hp/gdb.threads-hp/ directory
5298 * New command "set max-user-call-depth <nnn>"
5300 This command allows the user to limit the call depth of user-defined
5301 commands. The default is 1024.
5303 * Changes in FreeBSD/i386 native debugging.
5305 Support for the "generate-core-file" has been added.
5307 * New commands "dump", "append", and "restore".
5309 These commands allow data to be copied from target memory
5310 to a bfd-format or binary file (dump and append), and back
5311 from a file into memory (restore).
5313 * Improved "next/step" support on multi-processor Alpha Tru64.
5315 The previous single-step mechanism could cause unpredictable problems,
5316 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5317 of a software single-step mechanism prevents this.
5319 *** Changes in GDB 5.2.1:
5327 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5328 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5329 Fix, by Joel Brobecker imported from mainline.
5331 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5332 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5333 Fix, by Fred Fish, imported from mainline.
5335 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5336 Surprisingly enough, it works now.
5337 By Michal Ludvig, imported from mainline.
5339 i386 hardware watchpoint support:
5340 avoid misses on second run for some targets.
5341 By Pierre Muller, imported from mainline.
5343 *** Changes in GDB 5.2:
5345 * New command "set trust-readonly-sections on[off]".
5347 This command is a hint that tells gdb that read-only sections
5348 really are read-only (ie. that their contents will not change).
5349 In this mode, gdb will go to the object file rather than the
5350 target to read memory from read-only sections (such as ".text").
5351 This can be a significant performance improvement on some
5352 (notably embedded) targets.
5354 * New command "generate-core-file" (or "gcore").
5356 This new gdb command allows the user to drop a core file of the child
5357 process state at any time. So far it's been implemented only for
5358 GNU/Linux and Solaris, but should be relatively easily ported to other
5359 hosts. Argument is core file name (defaults to core.<pid>).
5361 * New command line option
5363 GDB now accepts --pid or -p followed by a process id.
5365 * Change in command line behavior -- corefiles vs. process ids.
5367 There is a subtle behavior in the way in which GDB handles
5368 command line arguments. The first non-flag argument is always
5369 a program to debug, but the second non-flag argument may either
5370 be a corefile or a process id. Previously, GDB would attempt to
5371 open the second argument as a corefile, and if that failed, would
5372 issue a superfluous error message and then attempt to attach it as
5373 a process. Now, if the second argument begins with a non-digit,
5374 it will be treated as a corefile. If it begins with a digit,
5375 GDB will attempt to attach it as a process, and if no such process
5376 is found, will then attempt to open it as a corefile.
5378 * Changes in ARM configurations.
5380 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5381 configuration is fully multi-arch.
5383 * New native configurations
5385 ARM NetBSD arm*-*-netbsd*
5386 x86 OpenBSD i[3456]86-*-openbsd*
5387 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5388 Sparc64 running FreeBSD sparc64-*-freebsd*
5392 Sanyo XStormy16 xstormy16-elf
5394 * OBSOLETE configurations and files
5396 Configurations that have been declared obsolete in this release have
5397 been commented out. Unless there is activity to revive these
5398 configurations, the next release of GDB will have their sources
5399 permanently REMOVED.
5401 AMD 29k family via UDI a29k-amd-udi, udi29k
5402 A29K VxWorks a29k-*-vxworks
5403 AMD 29000 embedded, using EBMON a29k-none-none
5404 AMD 29000 embedded with COFF a29k-none-coff
5405 AMD 29000 embedded with a.out a29k-none-aout
5407 testsuite/gdb.hp/gdb.threads-hp/ directory
5409 * REMOVED configurations and files
5411 TI TMS320C80 tic80-*-*
5413 PowerPC Solaris powerpcle-*-solaris*
5414 PowerPC Windows NT powerpcle-*-cygwin32
5415 PowerPC Netware powerpc-*-netware*
5416 Harris/CXUX m88k m88*-harris-cxux*
5417 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5418 ns32k-utek-sysv* ns32k-utek-*
5419 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5420 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5421 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5422 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5423 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5425 * Changes to command line processing
5427 The new `--args' feature can be used to specify command-line arguments
5428 for the inferior from gdb's command line.
5430 * Changes to key bindings
5432 There is a new `operate-and-get-next' function bound to `C-o'.
5434 *** Changes in GDB 5.1.1
5436 Fix compile problem on DJGPP.
5438 Fix a problem with floating-point registers on the i386 being
5441 Fix to stop GDB crashing on .debug_str debug info.
5443 Numerous documentation fixes.
5445 Numerous testsuite fixes.
5447 *** Changes in GDB 5.1:
5449 * New native configurations
5451 Alpha FreeBSD alpha*-*-freebsd*
5452 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5453 MIPS GNU/Linux mips*-*-linux*
5454 MIPS SGI Irix 6.x mips*-sgi-irix6*
5455 ia64 AIX ia64-*-aix*
5456 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5460 Motorola 68HC11 and 68HC12 m68hc11-elf
5462 UltraSparc running GNU/Linux sparc64-*-linux*
5464 * OBSOLETE configurations and files
5466 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5467 Harris/CXUX m88k m88*-harris-cxux*
5468 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5469 ns32k-utek-sysv* ns32k-utek-*
5470 TI TMS320C80 tic80-*-*
5472 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5473 PowerPC Solaris powerpcle-*-solaris*
5474 PowerPC Windows NT powerpcle-*-cygwin32
5475 PowerPC Netware powerpc-*-netware*
5476 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5477 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5478 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5479 Apple Macintosh (MPW) host N/A
5481 stuff.c (Program to stuff files into a specially prepared space in kdb)
5482 kdb-start.c (Main loop for the standalone kernel debugger)
5484 Configurations that have been declared obsolete in this release have
5485 been commented out. Unless there is activity to revive these
5486 configurations, the next release of GDB will have their sources
5487 permanently REMOVED.
5489 * REMOVED configurations and files
5491 Altos 3068 m68*-altos-*
5492 Convex c1-*-*, c2-*-*
5494 ARM RISCix arm-*-* (as host)
5498 * GDB has been converted to ISO C.
5500 GDB's source code has been converted to ISO C. In particular, the
5501 sources are fully protoized, and rely on standard headers being
5506 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5508 * The MI enabled by default.
5510 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5511 revised and enabled by default. Packages which use GDB as a debugging
5512 engine behind a UI or another front end are encouraged to switch to
5513 using the GDB/MI interface, instead of the old annotations interface
5514 which is now deprecated.
5516 * Support for debugging Pascal programs.
5518 GDB now includes support for debugging Pascal programs. The following
5519 main features are supported:
5521 - Pascal-specific data types such as sets;
5523 - automatic recognition of Pascal sources based on file-name
5526 - Pascal-style display of data types, variables, and functions;
5528 - a Pascal expression parser.
5530 However, some important features are not yet supported.
5532 - Pascal string operations are not supported at all;
5534 - there are some problems with boolean types;
5536 - Pascal type hexadecimal constants are not supported
5537 because they conflict with the internal variables format;
5539 - support for Pascal objects and classes is not full yet;
5541 - unlike Pascal, GDB is case-sensitive for symbol names.
5543 * Changes in completion.
5545 Commands such as `shell', `run' and `set args', which pass arguments
5546 to inferior programs, now complete on file names, similar to what
5547 users expect at the shell prompt.
5549 Commands which accept locations, such as `disassemble', `print',
5550 `breakpoint', `until', etc. now complete on filenames as well as
5551 program symbols. Thus, if you type "break foob TAB", and the source
5552 files linked into the programs include `foobar.c', that file name will
5553 be one of the candidates for completion. However, file names are not
5554 considered for completion after you typed a colon that delimits a file
5555 name from a name of a function in that file, as in "break foo.c:bar".
5557 `set demangle-style' completes on available demangling styles.
5559 * New platform-independent commands:
5561 It is now possible to define a post-hook for a command as well as a
5562 hook that runs before the command. For more details, see the
5563 documentation of `hookpost' in the GDB manual.
5565 * Changes in GNU/Linux native debugging.
5567 Support for debugging multi-threaded programs has been completely
5568 revised for all platforms except m68k and sparc. You can now debug as
5569 many threads as your system allows you to have.
5571 Attach/detach is supported for multi-threaded programs.
5573 Support for SSE registers was added for x86. This doesn't work for
5574 multi-threaded programs though.
5576 * Changes in MIPS configurations.
5578 Multi-arch support is enabled for all MIPS configurations.
5580 GDB can now be built as native debugger on SGI Irix 6.x systems for
5581 debugging n32 executables. (Debugging 64-bit executables is not yet
5584 * Unified support for hardware watchpoints in all x86 configurations.
5586 Most (if not all) native x86 configurations support hardware-assisted
5587 breakpoints and watchpoints in a unified manner. This support
5588 implements debug register sharing between watchpoints, which allows to
5589 put a virtually infinite number of watchpoints on the same address,
5590 and also supports watching regions up to 16 bytes with several debug
5593 The new maintenance command `maintenance show-debug-regs' toggles
5594 debugging print-outs in functions that insert, remove, and test
5595 watchpoints and hardware breakpoints.
5597 * Changes in the DJGPP native configuration.
5599 New command ``info dos sysinfo'' displays assorted information about
5600 the CPU, OS, memory, and DPMI server.
5602 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5603 display information about segment descriptors stored in GDT, LDT, and
5606 New commands ``info dos pde'' and ``info dos pte'' display entries
5607 from Page Directory and Page Tables (for now works with CWSDPMI only).
5608 New command ``info dos address-pte'' displays the Page Table entry for
5609 a given linear address.
5611 GDB can now pass command lines longer than 126 characters to the
5612 program being debugged (requires an update to the libdbg.a library
5613 which is part of the DJGPP development kit).
5615 DWARF2 debug info is now supported.
5617 It is now possible to `step' and `next' through calls to `longjmp'.
5619 * Changes in documentation.
5621 All GDB documentation was converted to GFDL, the GNU Free
5622 Documentation License.
5624 Tracepoints-related commands are now fully documented in the GDB
5627 TUI, the Text-mode User Interface, is now documented in the manual.
5629 Tracepoints-related commands are now fully documented in the GDB
5632 The "GDB Internals" manual now has an index. It also includes
5633 documentation of `ui_out' functions, GDB coding standards, x86
5634 hardware watchpoints, and memory region attributes.
5636 * GDB's version number moved to ``version.in''
5638 The Makefile variable VERSION has been replaced by the file
5639 ``version.in''. People creating GDB distributions should update the
5640 contents of this file.
5644 GUD support is now a standard part of the EMACS distribution.
5646 *** Changes in GDB 5.0:
5648 * Improved support for debugging FP programs on x86 targets
5650 Unified and much-improved support for debugging floating-point
5651 programs on all x86 targets. In particular, ``info float'' now
5652 displays the FP registers in the same format on all x86 targets, with
5653 greater level of detail.
5655 * Improvements and bugfixes in hardware-assisted watchpoints
5657 It is now possible to watch array elements, struct members, and
5658 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5659 on x86 targets no longer erroneously trigger when the address is
5662 * Improvements in the native DJGPP version of GDB
5664 The distribution now includes all the scripts and auxiliary files
5665 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5666 machines ``out of the box''.
5668 The DJGPP version can now debug programs that use signals. It is
5669 possible to catch signals that happened in the debuggee, deliver
5670 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5671 would kill the program being debugged.) Programs that hook hardware
5672 interrupts (keyboard, timer, etc.) can also be debugged.
5674 It is now possible to debug DJGPP programs that redirect their
5675 standard handles or switch them to raw (as opposed to cooked) mode, or
5676 even close them. The command ``run < foo > bar'' works as expected,
5677 and ``info terminal'' reports useful information about the debuggee's
5678 terminal, including raw/cooked mode, redirection, etc.
5680 The DJGPP version now uses termios functions for console I/O, which
5681 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5684 DOS-style file names with drive letters are now fully supported by
5687 It is now possible to debug DJGPP programs that switch their working
5688 directory. It is also possible to rerun the debuggee any number of
5689 times without restarting GDB; thus, you can use the same setup,
5690 breakpoints, etc. for many debugging sessions.
5692 * New native configurations
5694 ARM GNU/Linux arm*-*-linux*
5695 PowerPC GNU/Linux powerpc-*-linux*
5699 Motorola MCore mcore-*-*
5700 x86 VxWorks i[3456]86-*-vxworks*
5701 PowerPC VxWorks powerpc-*-vxworks*
5702 TI TMS320C80 tic80-*-*
5704 * OBSOLETE configurations
5706 Altos 3068 m68*-altos-*
5707 Convex c1-*-*, c2-*-*
5709 ARM RISCix arm-*-* (as host)
5712 Configurations that have been declared obsolete will be commented out,
5713 but the code will be left in place. If there is no activity to revive
5714 these configurations before the next release of GDB, the sources will
5715 be permanently REMOVED.
5717 * Gould support removed
5719 Support for the Gould PowerNode and NP1 has been removed.
5721 * New features for SVR4
5723 On SVR4 native platforms (such as Solaris), if you attach to a process
5724 without first loading a symbol file, GDB will now attempt to locate and
5725 load symbols from the running process's executable file.
5727 * Many C++ enhancements
5729 C++ support has been greatly improved. Overload resolution now works properly
5730 in almost all cases. RTTI support is on the way.
5732 * Remote targets can connect to a sub-program
5734 A popen(3) style serial-device has been added. This device starts a
5735 sub-process (such as a stand-alone simulator) and then communicates
5736 with that. The sub-program to run is specified using the syntax
5737 ``|<program> <args>'' vis:
5739 (gdb) set remotedebug 1
5740 (gdb) target extended-remote |mn10300-elf-sim program-args
5742 * MIPS 64 remote protocol
5744 A long standing bug in the mips64 remote protocol where by GDB
5745 expected certain 32 bit registers (ex SR) to be transfered as 32
5746 instead of 64 bits has been fixed.
5748 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5749 added to provide backward compatibility with older versions of GDB.
5751 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5753 The command ``set remotebinarydownload'' command has been replaced by
5754 ``set remote X-packet''. Other commands in ``set remote'' family
5755 include ``set remote P-packet''.
5757 * Breakpoint commands accept ranges.
5759 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5760 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5761 ``tracepoint passcount'' also accepts a range of tracepoints.
5763 * ``apropos'' command added.
5765 The ``apropos'' command searches through command names and
5766 documentation strings, printing out matches, making it much easier to
5767 try to find a command that does what you are looking for.
5771 A new machine oriented interface (MI) has been added to GDB. This
5772 interface is designed for debug environments running GDB as a separate
5773 process. This is part of the long term libGDB project. See the
5774 "GDB/MI" chapter of the GDB manual for further information. It can be
5775 enabled by configuring with:
5777 .../configure --enable-gdbmi
5779 *** Changes in GDB-4.18:
5781 * New native configurations
5783 HP-UX 10.20 hppa*-*-hpux10.20
5784 HP-UX 11.x hppa*-*-hpux11.0*
5785 M68K GNU/Linux m68*-*-linux*
5789 Fujitsu FR30 fr30-*-elf*
5790 Intel StrongARM strongarm-*-*
5791 Mitsubishi D30V d30v-*-*
5793 * OBSOLETE configurations
5795 Gould PowerNode, NP1 np1-*-*, pn-*-*
5797 Configurations that have been declared obsolete will be commented out,
5798 but the code will be left in place. If there is no activity to revive
5799 these configurations before the next release of GDB, the sources will
5800 be permanently REMOVED.
5804 As a compatibility experiment, GDB's source files buildsym.h and
5805 buildsym.c have been converted to pure standard C, no longer
5806 containing any K&R compatibility code. We believe that all systems in
5807 use today either come with a standard C compiler, or have a GCC port
5808 available. If this is not true, please report the affected
5809 configuration to bug-gdb@gnu.org immediately. See the README file for
5810 information about getting a standard C compiler if you don't have one
5815 GDB now uses readline 2.2.
5817 * set extension-language
5819 You can now control the mapping between filename extensions and source
5820 languages by using the `set extension-language' command. For instance,
5821 you can ask GDB to treat .c files as C++ by saying
5822 set extension-language .c c++
5823 The command `info extensions' lists all of the recognized extensions
5824 and their associated languages.
5826 * Setting processor type for PowerPC and RS/6000
5828 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5829 you can use the `set processor' command to specify what variant of the
5830 PowerPC family you are debugging. The command
5834 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5835 following PowerPC and RS6000 variants:
5837 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5838 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5840 403GC IBM PowerPC 403GC
5841 505 Motorola PowerPC 505
5842 860 Motorola PowerPC 860 or 850
5843 601 Motorola PowerPC 601
5844 602 Motorola PowerPC 602
5845 603 Motorola/IBM PowerPC 603 or 603e
5846 604 Motorola PowerPC 604 or 604e
5847 750 Motorola/IBM PowerPC 750 or 750
5849 At the moment, this command just tells GDB what to name the
5850 special-purpose processor registers. Since almost all the affected
5851 registers are inaccessible to user-level programs, this command is
5852 only useful for remote debugging in its present form.
5856 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5857 more extensive support for HP-UX. Added features include shared
5858 library support, kernel threads and hardware watchpoints for 11.00,
5859 support for HP's ANSI C and C++ compilers, and a compatibility mode
5860 for xdb and dbx commands.
5864 HP's donation includes the new concept of catchpoints, which is a
5865 generalization of the old catch command. On HP-UX, it is now possible
5866 to catch exec, fork, and vfork, as well as library loading.
5868 This means that the existing catch command has changed; its first
5869 argument now specifies the type of catch to be set up. See the
5870 output of "help catch" for a list of catchpoint types.
5872 * Debugging across forks
5874 On HP-UX, you can choose which process to debug when a fork() happens
5879 HP has donated a curses-based terminal user interface (TUI). To get
5880 it, build with --enable-tui. Although this can be enabled for any
5881 configuration, at present it only works for native HP debugging.
5883 * GDB remote protocol additions
5885 A new protocol packet 'X' that writes binary data is now available.
5886 Default behavior is to try 'X', then drop back to 'M' if the stub
5887 fails to respond. The settable variable `remotebinarydownload'
5888 allows explicit control over the use of 'X'.
5890 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5891 full 64-bit address. The command
5893 set remoteaddresssize 32
5895 can be used to revert to the old behaviour. For existing remote stubs
5896 the change should not be noticed, as the additional address information
5899 In order to assist in debugging stubs, you may use the maintenance
5900 command `packet' to send any text string to the stub. For instance,
5902 maint packet heythere
5904 sends the packet "$heythere#<checksum>". Note that it is very easy to
5905 disrupt a debugging session by sending the wrong packet at the wrong
5908 The compare-sections command allows you to compare section data on the
5909 target to what is in the executable file without uploading or
5910 downloading, by comparing CRC checksums.
5912 * Tracing can collect general expressions
5914 You may now collect general expressions at tracepoints. This requires
5915 further additions to the target-side stub; see tracepoint.c and
5916 doc/agentexpr.texi for further details.
5918 * mask-address variable for Mips
5920 For Mips targets, you may control the zeroing of the upper 32 bits of
5921 a 64-bit address by entering `set mask-address on'. This is mainly
5922 of interest to users of embedded R4xxx and R5xxx processors.
5924 * Higher serial baud rates
5926 GDB's serial code now allows you to specify baud rates 57600, 115200,
5927 230400, and 460800 baud. (Note that your host system may not be able
5928 to achieve all of these rates.)
5932 The i960 configuration now includes an initial implementation of a
5933 builtin simulator, contributed by Jim Wilson.
5936 *** Changes in GDB-4.17:
5938 * New native configurations
5940 Alpha GNU/Linux alpha*-*-linux*
5941 Unixware 2.x i[3456]86-unixware2*
5942 Irix 6.x mips*-sgi-irix6*
5943 PowerPC GNU/Linux powerpc-*-linux*
5944 PowerPC Solaris powerpcle-*-solaris*
5945 Sparc GNU/Linux sparc-*-linux*
5946 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5950 Argonaut Risc Chip (ARC) arc-*-*
5951 Hitachi H8/300S h8300*-*-*
5952 Matsushita MN10200 w/simulator mn10200-*-*
5953 Matsushita MN10300 w/simulator mn10300-*-*
5954 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5955 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5956 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5957 Mitsubishi D10V w/simulator d10v-*-*
5958 Mitsubishi M32R/D w/simulator m32r-*-elf*
5959 Tsqware Sparclet sparclet-*-*
5960 NEC V850 w/simulator v850-*-*
5962 * New debugging protocols
5964 ARM with RDI protocol arm*-*-*
5965 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5966 DDB and LSI variants of PMON protocol mips*-*-*
5967 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5968 PowerPC with SDS protocol powerpc{,le}-*-eabi
5969 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5973 All configurations can now understand and use the DWARF 2 debugging
5974 format. The choice is automatic, if the symbol file contains DWARF 2
5979 GDB now includes basic Java language support. This support is
5980 only useful with Java compilers that produce native machine code.
5982 * solib-absolute-prefix and solib-search-path
5984 For SunOS and SVR4 shared libraries, you may now set the prefix for
5985 loading absolute shared library symbol files, and the search path for
5986 locating non-absolute shared library symbol files.
5988 * Live range splitting
5990 GDB can now effectively debug code for which GCC has performed live
5991 range splitting as part of its optimization. See gdb/doc/LRS for
5992 more details on the expected format of the stabs information.
5996 GDB's support for the GNU Hurd, including thread debugging, has been
5997 updated to work with current versions of the Hurd.
6001 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6002 instruction set. ARM GDB automatically detects when Thumb
6003 instructions are in use, and adjusts disassembly and backtracing
6008 GDB's MIPS target configurations now handle the MIP16 16-bit
6013 GDB now includes support for overlays; if an executable has been
6014 linked such that multiple sections are based at the same address, GDB
6015 will decide which section to use for symbolic info. You can choose to
6016 control the decision manually, using overlay commands, or implement
6017 additional target-side support and use "overlay load-target" to bring
6018 in the overlay mapping. Do "help overlay" for more detail.
6022 The command "info symbol <address>" displays information about
6023 the symbol at the specified address.
6027 The standard remote protocol now includes an extension that allows
6028 asynchronous collection and display of trace data. This requires
6029 extensive support in the target-side debugging stub. Tracing mode
6030 includes a new interaction mode in GDB and new commands: see the
6031 file tracepoint.c for more details.
6035 Configurations for embedded MIPS now include a simulator contributed
6036 by Cygnus Solutions. The simulator supports the instruction sets
6037 of most MIPS variants.
6041 Sparc configurations may now include the ERC32 simulator contributed
6042 by the European Space Agency. The simulator is not built into
6043 Sparc targets by default; configure with --enable-sim to include it.
6047 For target configurations that may include multiple variants of a
6048 basic architecture (such as MIPS and SH), you may now set the
6049 architecture explicitly. "set arch" sets, "info arch" lists
6050 the possible architectures.
6052 *** Changes in GDB-4.16:
6054 * New native configurations
6056 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6057 M68K NetBSD m68k-*-netbsd*
6058 PowerPC AIX 4.x powerpc-*-aix*
6059 PowerPC MacOS powerpc-*-macos*
6060 PowerPC Windows NT powerpcle-*-cygwin32
6061 RS/6000 AIX 4.x rs6000-*-aix4*
6065 ARM with RDP protocol arm-*-*
6066 I960 with MON960 i960-*-coff
6067 MIPS VxWorks mips*-*-vxworks*
6068 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6069 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6071 Matra Sparclet sparclet-*-*
6075 The powerpc-eabi configuration now includes the PSIM simulator,
6076 contributed by Andrew Cagney, with assistance from Mike Meissner.
6077 PSIM is a very elaborate model of the PowerPC, including not only
6078 basic instruction set execution, but also details of execution unit
6079 performance and I/O hardware. See sim/ppc/README for more details.
6083 GDB now works with Solaris 2.5.
6085 * Windows 95/NT native
6087 GDB will now work as a native debugger on Windows 95 and Windows NT.
6088 To build it from source, you must use the "gnu-win32" environment,
6089 which uses a DLL to emulate enough of Unix to run the GNU tools.
6090 Further information, binaries, and sources are available at
6091 ftp.cygnus.com, under pub/gnu-win32.
6093 * dont-repeat command
6095 If a user-defined command includes the command `dont-repeat', then the
6096 command will not be repeated if the user just types return. This is
6097 useful if the command is time-consuming to run, so that accidental
6098 extra keystrokes don't run the same command many times.
6100 * Send break instead of ^C
6102 The standard remote protocol now includes an option to send a break
6103 rather than a ^C to the target in order to interrupt it. By default,
6104 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6106 * Remote protocol timeout
6108 The standard remote protocol includes a new variable `remotetimeout'
6109 that allows you to set the number of seconds before GDB gives up trying
6110 to read from the target. The default value is 2.
6112 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6114 By default GDB will automatically keep track of objects as they are
6115 loaded and unloaded by the dynamic linker. By using the command `set
6116 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6117 when shared library events occur, thus allowing you to set breakpoints
6118 in shared libraries which are explicitly loaded by the inferior.
6120 Note this feature does not work on hpux8. On hpux9 you must link
6121 /usr/lib/end.o into your program. This feature should work
6122 automatically on hpux10.
6124 * Irix 5.x hardware watchpoint support
6126 Irix 5 configurations now support the use of hardware watchpoints.
6128 * Mips protocol "SYN garbage limit"
6130 When debugging a Mips target using the `target mips' protocol, you
6131 may set the number of characters that GDB will ignore by setting
6132 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6133 every character. The default value is 1050.
6135 * Recording and replaying remote debug sessions
6137 If you set `remotelogfile' to the name of a file, gdb will write to it
6138 a recording of a remote debug session. This recording may then be
6139 replayed back to gdb using "gdbreplay". See gdbserver/README for
6140 details. This is useful when you have a problem with GDB while doing
6141 remote debugging; you can make a recording of the session and send it
6142 to someone else, who can then recreate the problem.
6144 * Speedups for remote debugging
6146 GDB includes speedups for downloading and stepping MIPS systems using
6147 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6148 and more efficient S-record downloading.
6150 * Memory use reductions and statistics collection
6152 GDB now uses less memory and reports statistics about memory usage.
6153 Try the `maint print statistics' command, for example.
6155 *** Changes in GDB-4.15:
6157 * Psymtabs for XCOFF
6159 The symbol reader for AIX GDB now uses partial symbol tables. This
6160 can greatly improve startup time, especially for large executables.
6162 * Remote targets use caching
6164 Remote targets now use a data cache to speed up communication with the
6165 remote side. The data cache could lead to incorrect results because
6166 it doesn't know about volatile variables, thus making it impossible to
6167 debug targets which use memory mapped I/O devices. `set remotecache
6168 off' turns the the data cache off.
6170 * Remote targets may have threads
6172 The standard remote protocol now includes support for multiple threads
6173 in the target system, using new protocol commands 'H' and 'T'. See
6174 gdb/remote.c for details.
6178 If GDB is configured with `--enable-netrom', then it will include
6179 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6180 acts as though it is a bank of ROM on the target board, but you can
6181 write into it over the network. GDB's support consists only of
6182 support for fast loading into the emulated ROM; to debug, you must use
6183 another protocol, such as standard remote protocol. The usual
6184 sequence is something like
6186 target nrom <netrom-hostname>
6188 target remote <netrom-hostname>:1235
6192 GDB now includes support for the Apple Macintosh, as a host only. It
6193 may be run as either an MPW tool or as a standalone application, and
6194 it can debug through the serial port. All the usual GDB commands are
6195 available, but to the target command, you must supply "serial" as the
6196 device type instead of "/dev/ttyXX". See mpw-README in the main
6197 directory for more information on how to build. The MPW configuration
6198 scripts */mpw-config.in support only a few targets, and only the
6199 mips-idt-ecoff target has been tested.
6203 GDB configuration now uses autoconf. This is not user-visible,
6204 but does simplify configuration and building.
6208 GDB now supports hpux10.
6210 *** Changes in GDB-4.14:
6212 * New native configurations
6214 x86 FreeBSD i[345]86-*-freebsd
6215 x86 NetBSD i[345]86-*-netbsd
6216 NS32k NetBSD ns32k-*-netbsd
6217 Sparc NetBSD sparc-*-netbsd
6221 A29K VxWorks a29k-*-vxworks
6222 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6223 CPU32 EST-300 emulator m68*-*-est*
6224 PowerPC ELF powerpc-*-elf
6227 * Alpha OSF/1 support for procfs
6229 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6230 possible to attach to running processes. As the mounting of the /proc
6231 filesystem is optional on the Alpha, GDB automatically determines
6232 the availability of /proc during startup. This can lead to problems
6233 if /proc is unmounted after GDB has been started.
6235 * Arguments to user-defined commands
6237 User commands may accept up to 10 arguments separated by whitespace.
6238 Arguments are accessed within the user command via $arg0..$arg9. A
6241 print $arg0 + $arg1 + $arg2
6243 To execute the command use:
6246 Defines the command "adder" which prints the sum of its three arguments.
6247 Note the arguments are text substitutions, so they may reference variables,
6248 use complex expressions, or even perform inferior function calls.
6250 * New `if' and `while' commands
6252 This makes it possible to write more sophisticated user-defined
6253 commands. Both commands take a single argument, which is the
6254 expression to evaluate, and must be followed by the commands to
6255 execute, one per line, if the expression is nonzero, the list being
6256 terminated by the word `end'. The `if' command list may include an
6257 `else' word, which causes the following commands to be executed only
6258 if the expression is zero.
6260 * Fortran source language mode
6262 GDB now includes partial support for Fortran 77. It will recognize
6263 Fortran programs and can evaluate a subset of Fortran expressions, but
6264 variables and functions may not be handled correctly. GDB will work
6265 with G77, but does not yet know much about symbols emitted by other
6268 * Better HPUX support
6270 Most debugging facilities now work on dynamic executables for HPPAs
6271 running hpux9 or later. You can attach to running dynamically linked
6272 processes, but by default the dynamic libraries will be read-only, so
6273 for instance you won't be able to put breakpoints in them. To change
6274 that behavior do the following before running the program:
6280 This will cause the libraries to be mapped private and read-write.
6281 To revert to the normal behavior, do this:
6287 You cannot set breakpoints or examine data in the library until after
6288 the library is loaded if the function/data symbols do not have
6291 GDB can now also read debug symbols produced by the HP C compiler on
6292 HPPAs (sorry, no C++, Fortran or 68k support).
6294 * Target byte order now dynamically selectable
6296 You can choose which byte order to use with a target system, via the
6297 commands "set endian big" and "set endian little", and you can see the
6298 current setting by using "show endian". You can also give the command
6299 "set endian auto", in which case GDB will use the byte order
6300 associated with the executable. Currently, only embedded MIPS
6301 configurations support dynamic selection of target byte order.
6303 * New DOS host serial code
6305 This version uses DPMI interrupts to handle buffered I/O, so you
6306 no longer need to run asynctsr when debugging boards connected to
6309 *** Changes in GDB-4.13:
6311 * New "complete" command
6313 This lists all the possible completions for the rest of the line, if it
6314 were to be given as a command itself. This is intended for use by emacs.
6316 * Trailing space optional in prompt
6318 "set prompt" no longer adds a space for you after the prompt you set. This
6319 allows you to set a prompt which ends in a space or one that does not.
6321 * Breakpoint hit counts
6323 "info break" now displays a count of the number of times the breakpoint
6324 has been hit. This is especially useful in conjunction with "ignore"; you
6325 can ignore a large number of breakpoint hits, look at the breakpoint info
6326 to see how many times the breakpoint was hit, then run again, ignoring one
6327 less than that number, and this will get you quickly to the last hit of
6330 * Ability to stop printing at NULL character
6332 "set print null-stop" will cause GDB to stop printing the characters of
6333 an array when the first NULL is encountered. This is useful when large
6334 arrays actually contain only short strings.
6336 * Shared library breakpoints
6338 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6339 breakpoints in shared libraries before the executable is run.
6341 * Hardware watchpoints
6343 There is a new hardware breakpoint for the watch command for sparclite
6344 targets. See gdb/sparclite/hw_breakpoint.note.
6346 Hardware watchpoints are also now supported under GNU/Linux.
6350 Annotations have been added. These are for use with graphical interfaces,
6351 and are still experimental. Currently only gdba.el uses these.
6353 * Improved Irix 5 support
6355 GDB now works properly with Irix 5.2.
6357 * Improved HPPA support
6359 GDB now works properly with the latest GCC and GAS.
6361 * New native configurations
6363 Sequent PTX4 i[34]86-sequent-ptx4
6364 HPPA running OSF/1 hppa*-*-osf*
6365 Atari TT running SVR4 m68*-*-sysv4*
6366 RS/6000 LynxOS rs6000-*-lynxos*
6370 OS/9000 i[34]86-*-os9k
6371 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6374 * Hitachi SH7000 and E7000-PC ICE support
6376 There is now support for communicating with the Hitachi E7000-PC ICE.
6377 This is available automatically when GDB is configured for the SH.
6381 As usual, a variety of small fixes and improvements, both generic
6382 and configuration-specific. See the ChangeLog for more detail.
6384 *** Changes in GDB-4.12:
6386 * Irix 5 is now supported
6390 GDB-4.12 on the HPPA has a number of changes which make it unable
6391 to debug the output from the currently released versions of GCC and
6392 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6393 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6394 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6397 *** Changes in GDB-4.11:
6399 * User visible changes:
6403 The "set remotedebug" option is now consistent between the mips remote
6404 target, remote targets using the gdb-specific protocol, UDI (AMD's
6405 debug protocol for the 29k) and the 88k bug monitor. It is now an
6406 integer specifying a debug level (normally 0 or 1, but 2 means more
6407 debugging info for the mips target).
6409 * DEC Alpha native support
6411 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6412 debug info, but GDB works fairly well with the DEC compiler and should
6413 work with a future GCC release. See the README file for a few
6414 Alpha-specific notes.
6416 * Preliminary thread implementation
6418 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6420 * LynxOS native and target support for 386
6422 This release has been hosted on LynxOS 2.2, and also can be configured
6423 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6426 * Improvements in C++ mangling/demangling.
6428 This release has much better g++ debugging, specifically in name
6429 mangling/demangling, virtual function calls, print virtual table,
6430 call methods, ...etc.
6432 *** Changes in GDB-4.10:
6434 * User visible changes:
6436 Remote debugging using the GDB-specific (`target remote') protocol now
6437 supports the `load' command. This is only useful if you have some
6438 other way of getting the stub to the target system, and you can put it
6439 somewhere in memory where it won't get clobbered by the download.
6441 Filename completion now works.
6443 When run under emacs mode, the "info line" command now causes the
6444 arrow to point to the line specified. Also, "info line" prints
6445 addresses in symbolic form (as well as hex).
6447 All vxworks based targets now support a user settable option, called
6448 vxworks-timeout. This option represents the number of seconds gdb
6449 should wait for responses to rpc's. You might want to use this if
6450 your vxworks target is, perhaps, a slow software simulator or happens
6451 to be on the far side of a thin network line.
6455 This release contains support for using a DEC alpha as a GDB host for
6456 cross debugging. Native alpha debugging is not supported yet.
6459 *** Changes in GDB-4.9:
6463 This is the first GDB release which is accompanied by a matching testsuite.
6464 The testsuite requires installation of dejagnu, which should be available
6465 via ftp from most sites that carry GNU software.
6469 'Cfront' style demangling has had its name changed to 'ARM' style, to
6470 emphasize that it was written from the specifications in the C++ Annotated
6471 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6472 disclaimers, it still generated too much confusion with users attempting to
6473 use gdb with AT&T cfront.
6477 GDB now uses a standard remote interface to a simulator library.
6478 So far, the library contains simulators for the Zilog Z8001/2, the
6479 Hitachi H8/300, H8/500 and Super-H.
6481 * New targets supported
6483 H8/300 simulator h8300-hitachi-hms or h8300hms
6484 H8/500 simulator h8500-hitachi-hms or h8500hms
6485 SH simulator sh-hitachi-hms or sh
6486 Z8000 simulator z8k-zilog-none or z8ksim
6487 IDT MIPS board over serial line mips-idt-ecoff
6489 Cross-debugging to GO32 targets is supported. It requires a custom
6490 version of the i386-stub.c module which is integrated with the
6491 GO32 memory extender.
6493 * New remote protocols
6495 MIPS remote debugging protocol.
6497 * New source languages supported
6499 This version includes preliminary support for Chill, a Pascal like language
6500 used by telecommunications companies. Chill support is also being integrated
6501 into the GNU compiler, but we don't know when it will be publically available.
6504 *** Changes in GDB-4.8:
6506 * HP Precision Architecture supported
6508 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6509 version of this support was available as a set of patches from the
6510 University of Utah. GDB does not support debugging of programs
6511 compiled with the HP compiler, because HP will not document their file
6512 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6513 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6515 Many problems in the preliminary version have been fixed.
6517 * Faster and better demangling
6519 We have improved template demangling and fixed numerous bugs in the GNU style
6520 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6521 character types (wchar_t) are now supported. Demangling of each symbol is now
6522 only done once, and is cached when the symbol table for a file is read in.
6523 This results in a small increase in memory usage for C programs, a moderate
6524 increase in memory usage for C++ programs, and a fantastic speedup in
6527 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6528 from the specifications in the Annotated Reference Manual, which AT&T's
6529 compiler does not actually implement.
6531 * G++ multiple inheritance compiler problem
6533 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6534 inheritance lattices was reworked to properly discover ambiguities. We
6535 recently found an example which causes this new algorithm to fail in a
6536 very subtle way, producing bad debug information for those classes.
6537 The file 'gcc.patch' (in this directory) can be applied to gcc to
6538 circumvent the problem. A future GCC release will contain a complete
6541 The previous G++ debug info problem (mentioned below for the gdb-4.7
6542 release) is fixed in gcc version 2.3.2.
6544 * Improved configure script
6546 The `configure' script will now attempt to guess your system type if
6547 you don't supply a host system type. The old scheme of supplying a
6548 host system triplet is preferable over using this. All the magic is
6549 done in the new `config.guess' script. Examine it for details.
6551 We have also brought our configure script much more in line with the FSF's
6552 version. It now supports the --with-xxx options. In particular,
6553 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6554 The resulting GDB will not be able to read arbitrary object file formats --
6555 only the format ``expected'' to be used on the configured target system.
6556 We hope to make this the default in a future release.
6558 * Documentation improvements
6560 There's new internal documentation on how to modify GDB, and how to
6561 produce clean changes to the code. We implore people to read it
6562 before submitting changes.
6564 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6565 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6566 `info' files are also provided. To build `info' files from scratch,
6567 you will need the latest `makeinfo' release, which will be available in
6568 a future texinfo-X.Y release.
6570 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6571 We're not sure exactly which versions have this problem, but it has
6572 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6573 or better. If that isn't possible, there is a patch in
6574 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6575 around this problem.
6579 GDB now supports array constants that can be used in expressions typed in by
6580 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6581 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6584 The new directory `gdb/sparclite' contains a program that demonstrates
6585 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6587 * New native hosts supported
6589 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6590 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6592 * New targets supported
6594 AMD 29k family via UDI a29k-amd-udi or udi29k
6596 * New file formats supported
6598 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6599 HPUX core files, and SCO 3.2v2 core files.
6603 Attaching to processes now works again; thanks for the many bug reports.
6605 We have also stomped on a bunch of core dumps caused by
6606 printf_filtered("%s") problems.
6608 We eliminated a copyright problem on the rpc and ptrace header files
6609 for VxWorks, which was discovered at the last minute during the 4.7
6610 release. You should now be able to build a VxWorks GDB.
6612 You can now interrupt gdb while an attached process is running. This
6613 will cause the attached process to stop, and give control back to GDB.
6615 We fixed problems caused by using too many file descriptors
6616 for reading symbols from object files and libraries. This was
6617 especially a problem for programs that used many (~100) shared
6620 The `step' command now only enters a subroutine if there is line number
6621 information for the subroutine. Otherwise it acts like the `next'
6622 command. Previously, `step' would enter subroutines if there was
6623 any debugging information about the routine. This avoids problems
6624 when using `cc -g1' on MIPS machines.
6626 * Internal improvements
6628 GDB's internal interfaces have been improved to make it easier to support
6629 debugging of multiple languages in the future.
6631 GDB now uses a common structure for symbol information internally.
6632 Minimal symbols (derived from linkage symbols in object files), partial
6633 symbols (from a quick scan of debug information), and full symbols
6634 contain a common subset of information, making it easier to write
6635 shared code that handles any of them.
6637 * New command line options
6639 We now accept --silent as an alias for --quiet.
6643 The memory-mapped-malloc library is now licensed under the GNU Library
6644 General Public License.
6646 *** Changes in GDB-4.7:
6648 * Host/native/target split
6650 GDB has had some major internal surgery to untangle the support for
6651 hosts and remote targets. Now, when you configure GDB for a remote
6652 target, it will no longer load in all of the support for debugging
6653 local programs on the host. When fully completed and tested, this will
6654 ensure that arbitrary host/target combinations are possible.
6656 The primary conceptual shift is to separate the non-portable code in
6657 GDB into three categories. Host specific code is required any time GDB
6658 is compiled on that host, regardless of the target. Target specific
6659 code relates to the peculiarities of the target, but can be compiled on
6660 any host. Native specific code is everything else: it can only be
6661 built when the host and target are the same system. Child process
6662 handling and core file support are two common `native' examples.
6664 GDB's use of /proc for controlling Unix child processes is now cleaner.
6665 It has been split out into a single module under the `target_ops' vector,
6666 plus two native-dependent functions for each system that uses /proc.
6668 * New hosts supported
6670 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6671 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6672 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6674 * New targets supported
6676 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6677 68030 and CPU32 m68030-*-*, m68332-*-*
6679 * New native hosts supported
6681 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6682 (386bsd is not well tested yet)
6683 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6685 * New file formats supported
6687 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6688 supports reading of `a.out.adobe' object files, which are an a.out
6689 format extended with minimal information about multiple sections.
6693 `show copying' is the same as the old `info copying'.
6694 `show warranty' is the same as `info warrantee'.
6695 These were renamed for consistency. The old commands continue to work.
6697 `info handle' is a new alias for `info signals'.
6699 You can now define pre-command hooks, which attach arbitrary command
6700 scripts to any command. The commands in the hook will be executed
6701 prior to the user's command. You can also create a hook which will be
6702 executed whenever the program stops. See gdb.texinfo.
6706 We now deal with Cfront style name mangling, and can even extract type
6707 info from mangled symbols. GDB can automatically figure out which
6708 symbol mangling style your C++ compiler uses.
6710 Calling of methods and virtual functions has been improved as well.
6714 The crash that occured when debugging Sun Ansi-C compiled binaries is
6715 fixed. This was due to mishandling of the extra N_SO stabs output
6718 We also finally got Ultrix 4.2 running in house, and fixed core file
6719 support, with help from a dozen people on the net.
6721 John M. Farrell discovered that the reason that single-stepping was so
6722 slow on all of the Mips based platforms (primarily SGI and DEC) was
6723 that we were trying to demangle and lookup a symbol used for internal
6724 purposes on every instruction that was being stepped through. Changing
6725 the name of that symbol so that it couldn't be mistaken for a C++
6726 mangled symbol sped things up a great deal.
6728 Rich Pixley sped up symbol lookups in general by getting much smarter
6729 about when C++ symbol mangling is necessary. This should make symbol
6730 completion (TAB on the command line) much faster. It's not as fast as
6731 we'd like, but it's significantly faster than gdb-4.6.
6735 A new user controllable variable 'call_scratch_address' can
6736 specify the location of a scratch area to be used when GDB
6737 calls a function in the target. This is necessary because the
6738 usual method of putting the scratch area on the stack does not work
6739 in systems that have separate instruction and data spaces.
6741 We integrated changes to support the 29k UDI (Universal Debugger
6742 Interface), but discovered at the last minute that we didn't have all
6743 of the appropriate copyright paperwork. We are working with AMD to
6744 resolve this, and hope to have it available soon.
6748 We have sped up the remote serial line protocol, especially for targets
6749 with lots of registers. It now supports a new `expedited status' ('T')
6750 message which can be used in place of the existing 'S' status message.
6751 This allows the remote stub to send only the registers that GDB
6752 needs to make a quick decision about single-stepping or conditional
6753 breakpoints, eliminating the need to fetch the entire register set for
6754 each instruction being stepped through.
6756 The GDB remote serial protocol now implements a write-through cache for
6757 registers, only re-reading the registers if the target has run.
6759 There is also a new remote serial stub for SPARC processors. You can
6760 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6761 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6762 processor with a serial port.
6766 Configure.in files have become much easier to read and modify. A new
6767 `table driven' format makes it more obvious what configurations are
6768 supported, and what files each one uses.
6772 There is a new opcodes library which will eventually contain all of the
6773 disassembly routines and opcode tables. At present, it only contains
6774 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6775 disassembler (binutils/objdump) to share these routines.
6777 The libiberty library is now copylefted under the GNU Library General
6778 Public License. This allows more liberal use, and was done so libg++
6779 can use it. This makes no difference to GDB, since the Library License
6780 grants all the rights from the General Public License.
6784 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6785 reference to the stabs symbol info used by the debugger. It is (as far
6786 as we know) the only published document on this fascinating topic. We
6787 encourage you to read it, compare it to the stabs information on your
6788 system, and send improvements on the document in general (to
6789 bug-gdb@prep.ai.mit.edu).
6791 And, of course, many bugs have been fixed.
6794 *** Changes in GDB-4.6:
6796 * Better support for C++ function names
6798 GDB now accepts as input the "demangled form" of C++ overloaded function
6799 names and member function names, and can do command completion on such names
6800 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6801 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6802 Make use of command completion, it is your friend.
6804 GDB also now accepts a variety of C++ mangled symbol formats. They are
6805 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6806 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6807 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6808 for the list of formats.
6810 * G++ symbol mangling problem
6812 Recent versions of gcc have a bug in how they emit debugging information for
6813 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6814 directory) can be applied to gcc to fix the problem. Alternatively, if you
6815 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6816 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6817 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6820 * New 'maintenance' command
6822 All of the commands related to hacking GDB internals have been moved out of
6823 the main command set, and now live behind the 'maintenance' command. This
6824 can also be abbreviated as 'mt'. The following changes were made:
6826 dump-me -> maintenance dump-me
6827 info all-breakpoints -> maintenance info breakpoints
6828 printmsyms -> maintenance print msyms
6829 printobjfiles -> maintenance print objfiles
6830 printpsyms -> maintenance print psymbols
6831 printsyms -> maintenance print symbols
6833 The following commands are new:
6835 maintenance demangle Call internal GDB demangler routine to
6836 demangle a C++ link name and prints the result.
6837 maintenance print type Print a type chain for a given symbol
6839 * Change to .gdbinit file processing
6841 We now read the $HOME/.gdbinit file before processing the argv arguments
6842 (e.g. reading symbol files or core files). This allows global parameters to
6843 be set, which will apply during the symbol reading. The ./.gdbinit is still
6844 read after argv processing.
6846 * New hosts supported
6848 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6850 GNU/Linux support i386-unknown-linux or linux
6852 We are also including code to support the HP/PA running BSD and HPUX. This
6853 is almost guaranteed not to work, as we didn't have time to test or build it
6854 for this release. We are including it so that the more adventurous (or
6855 masochistic) of you can play with it. We also had major problems with the
6856 fact that the compiler that we got from HP doesn't support the -g option.
6859 * New targets supported
6861 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6863 * More smarts about finding #include files
6865 GDB now remembers the compilation directory for all include files, and for
6866 all files from which C is generated (like yacc and lex sources). This
6867 greatly improves GDB's ability to find yacc/lex sources, and include files,
6868 especially if you are debugging your program from a directory different from
6869 the one that contains your sources.
6871 We also fixed a bug which caused difficulty with listing and setting
6872 breakpoints in include files which contain C code. (In the past, you had to
6873 try twice in order to list an include file that you hadn't looked at before.)
6875 * Interesting infernals change
6877 GDB now deals with arbitrary numbers of sections, where the symbols for each
6878 section must be relocated relative to that section's landing place in the
6879 target's address space. This work was needed to support ELF with embedded
6880 stabs used by Solaris-2.0.
6882 * Bug fixes (of course!)
6884 There have been loads of fixes for the following things:
6885 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6886 i960, stabs, DOS(GO32), procfs, etc...
6888 See the ChangeLog for details.
6890 *** Changes in GDB-4.5:
6892 * New machines supported (host and target)
6894 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6896 SGI Irix-4.x mips-sgi-irix4 or iris4
6898 * New malloc package
6900 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6901 Mmalloc is capable of handling mutiple heaps of memory. It is also
6902 capable of saving a heap to a file, and then mapping it back in later.
6903 This can be used to greatly speedup the startup of GDB by using a
6904 pre-parsed symbol table which lives in a mmalloc managed heap. For
6905 more details, please read mmalloc/mmalloc.texi.
6909 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6910 'help info proc' for details.
6912 * MIPS ecoff symbol table format
6914 The code that reads MIPS symbol table format is now supported on all hosts.
6915 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6918 * File name changes for MS-DOS
6920 Many files in the config directories have been renamed to make it easier to
6921 support GDB on MS-DOSe systems (which have very restrictive file name
6922 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6923 environment) is close to working but has some remaining problems. Note
6924 that debugging of DOS programs is not supported, due to limitations
6925 in the ``operating system'', but it can be used to host cross-debugging.
6927 * Cross byte order fixes
6929 Many fixes have been made to support cross debugging of Sparc and MIPS
6930 targets from hosts whose byte order differs.
6932 * New -mapped and -readnow options
6934 If memory-mapped files are available on your system through the 'mmap'
6935 system call, you can use the -mapped option on the `file' or
6936 `symbol-file' commands to cause GDB to write the symbols from your
6937 program into a reusable file. If the program you are debugging is
6938 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6939 Future GDB debugging sessions will notice the presence of this file,
6940 and will quickly map in symbol information from it, rather than reading
6941 the symbol table from the executable program. Using the '-mapped'
6942 option in a GDB `file' or `symbol-file' command has the same effect as
6943 starting GDB with the '-mapped' command-line option.
6945 You can cause GDB to read the entire symbol table immediately by using
6946 the '-readnow' option with any of the commands that load symbol table
6947 information (or on the GDB command line). This makes the command
6948 slower, but makes future operations faster.
6950 The -mapped and -readnow options are typically combined in order to
6951 build a `fred.syms' file that contains complete symbol information.
6952 A simple GDB invocation to do nothing but build a `.syms' file for future
6955 gdb -batch -nx -mapped -readnow programname
6957 The `.syms' file is specific to the host machine on which GDB is run.
6958 It holds an exact image of GDB's internal symbol table. It cannot be
6959 shared across multiple host platforms.
6961 * longjmp() handling
6963 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6964 siglongjmp() without losing control. This feature has not yet been ported to
6965 all systems. It currently works on many 386 platforms, all MIPS-based
6966 platforms (SGI, DECstation, etc), and Sun3/4.
6970 Preliminary work has been put in to support the new Solaris OS from Sun. At
6971 this time, it can control and debug processes, but it is not capable of
6976 As always, many many bug fixes. The major areas were with g++, and mipsread.
6977 People using the MIPS-based platforms should experience fewer mysterious
6978 crashes and trashed symbol tables.
6980 *** Changes in GDB-4.4:
6982 * New machines supported (host and target)
6984 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6986 BSD Reno on Vax vax-dec-bsd
6987 Ultrix on Vax vax-dec-ultrix
6989 * New machines supported (target)
6991 AMD 29000 embedded, using EBMON a29k-none-none
6995 GDB continues to improve its handling of C++. `References' work better.
6996 The demangler has also been improved, and now deals with symbols mangled as
6997 per the Annotated C++ Reference Guide.
6999 GDB also now handles `stabs' symbol information embedded in MIPS
7000 `ecoff' symbol tables. Since the ecoff format was not easily
7001 extensible to handle new languages such as C++, this appeared to be a
7002 good way to put C++ debugging info into MIPS binaries. This option
7003 will be supported in the GNU C compiler, version 2, when it is
7006 * New features for SVR4
7008 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7009 shared libraries. Debugging dynamically linked programs should present
7010 only minor differences from debugging statically linked programs.
7012 The `info proc' command will print out information about any process
7013 on an SVR4 system (including the one you are debugging). At the moment,
7014 it prints the address mappings of the process.
7016 If you bring up GDB on another SVR4 system, please send mail to
7017 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7019 * Better dynamic linking support in SunOS
7021 Reading symbols from shared libraries which contain debugging symbols
7022 now works properly. However, there remain issues such as automatic
7023 skipping of `transfer vector' code during function calls, which
7024 make it harder to debug code in a shared library, than to debug the
7025 same code linked statically.
7029 GDB is now using the latest `getopt' routines from the FSF. This
7030 version accepts the -- prefix for options with long names. GDB will
7031 continue to accept the old forms (-option and +option) as well.
7032 Various single letter abbreviations for options have been explicity
7033 added to the option table so that they won't get overshadowed in the
7034 future by other options that begin with the same letter.
7038 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7039 Many assorted bugs have been handled. Many more remain to be handled.
7040 See the various ChangeLog files (primarily in gdb and bfd) for details.
7043 *** Changes in GDB-4.3:
7045 * New machines supported (host and target)
7047 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7048 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7049 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7051 * Almost SCO Unix support
7053 We had hoped to support:
7054 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7055 (except for core file support), but we discovered very late in the release
7056 that it has problems with process groups that render gdb unusable. Sorry
7057 about that. I encourage people to fix it and post the fixes.
7059 * Preliminary ELF and DWARF support
7061 GDB can read ELF object files on System V Release 4, and can handle
7062 debugging records for C, in DWARF format, in ELF files. This support
7063 is preliminary. If you bring up GDB on another SVR4 system, please
7064 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7069 GDB now uses the latest `readline' library. One user-visible change
7070 is that two tabs will list possible command completions, which previously
7071 required typing M-? (meta-question mark, or ESC ?).
7075 The `stepi' bug that many of you noticed has been squashed.
7076 Many bugs in C++ have been handled. Many more remain to be handled.
7077 See the various ChangeLog files (primarily in gdb and bfd) for details.
7079 * State of the MIPS world (in case you wondered):
7081 GDB can understand the symbol tables emitted by the compilers
7082 supplied by most vendors of MIPS-based machines, including DEC. These
7083 symbol tables are in a format that essentially nobody else uses.
7085 Some versions of gcc come with an assembler post-processor called
7086 mips-tfile. This program is required if you want to do source-level
7087 debugging of gcc-compiled programs. I believe FSF does not ship
7088 mips-tfile with gcc version 1, but it will eventually come with gcc
7091 Debugging of g++ output remains a problem. g++ version 1.xx does not
7092 really support it at all. (If you're lucky, you should be able to get
7093 line numbers and stack traces to work, but no parameters or local
7094 variables.) With some work it should be possible to improve the
7097 When gcc version 2 is released, you will have somewhat better luck.
7098 However, even then you will get confusing results for inheritance and
7101 We will eventually provide full debugging of g++ output on
7102 DECstations. This will probably involve some kind of stabs-in-ecoff
7103 encapulation, but the details have not been worked out yet.
7106 *** Changes in GDB-4.2:
7108 * Improved configuration
7110 Only one copy of `configure' exists now, and it is not self-modifying.
7111 Porting BFD is simpler.
7115 The `step' and `next' commands now only stop at the first instruction
7116 of a source line. This prevents the multiple stops that used to occur
7117 in switch statements, for-loops, etc. `Step' continues to stop if a
7118 function that has debugging information is called within the line.
7122 Lots of small bugs fixed. More remain.
7124 * New host supported (not target)
7126 Intel 386 PC clone running Mach i386-none-mach
7129 *** Changes in GDB-4.1:
7131 * Multiple source language support
7133 GDB now has internal scaffolding to handle several source languages.
7134 It determines the type of each source file from its filename extension,
7135 and will switch expression parsing and number formatting to match the
7136 language of the function in the currently selected stack frame.
7137 You can also specifically set the language to be used, with
7138 `set language c' or `set language modula-2'.
7142 GDB now has preliminary support for the GNU Modula-2 compiler,
7143 currently under development at the State University of New York at
7144 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7145 continue through the fall of 1991 and into 1992.
7147 Other Modula-2 compilers are currently not supported, and attempting to
7148 debug programs compiled with them will likely result in an error as the
7149 symbol table is read. Feel free to work on it, though!
7151 There are hooks in GDB for strict type checking and range checking,
7152 in the `Modula-2 philosophy', but they do not currently work.
7156 GDB can now write to executable and core files (e.g. patch
7157 a variable's value). You must turn this switch on, specify
7158 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7159 by assigning a new value to a variable. Modifications take
7162 * Automatic SunOS shared library reading
7164 When you run your program, GDB automatically determines where its
7165 shared libraries (if any) have been loaded, and reads their symbols.
7166 The `share' command is no longer needed. This also works when
7167 examining core files.
7171 You can specify the number of lines that the `list' command shows.
7174 * New machines supported (host and target)
7176 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7177 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7178 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7180 * New hosts supported (not targets)
7182 IBM RT/PC: romp-ibm-aix or rtpc
7184 * New targets supported (not hosts)
7186 AMD 29000 embedded with COFF a29k-none-coff
7187 AMD 29000 embedded with a.out a29k-none-aout
7188 Ultracomputer remote kernel debug a29k-nyu-kern
7190 * New remote interfaces
7196 *** Changes in GDB-4.0:
7200 Wide output is wrapped at good places to make the output more readable.
7202 Gdb now supports cross-debugging from a host machine of one type to a
7203 target machine of another type. Communication with the target system
7204 is over serial lines. The ``target'' command handles connecting to the
7205 remote system; the ``load'' command will download a program into the
7206 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7207 also supports debugging of realtime processes running under VxWorks,
7208 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7209 stub on the target system.
7211 New CPUs supported include the AMD 29000 and Intel 960.
7213 GDB now reads object files and symbol tables via a ``binary file''
7214 library, which allows a single copy of GDB to debug programs of multiple
7215 object file types such as a.out and coff.
7217 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7218 refcard.dvi and refcard.ps are available to format it).
7221 * Control-Variable user interface simplified
7223 All variables that control the operation of the debugger can be set
7224 by the ``set'' command, and displayed by the ``show'' command.
7226 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7227 ``Show prompt'' produces the response:
7228 Gdb's prompt is new-gdb=>.
7230 What follows are the NEW set commands. The command ``help set'' will
7231 print a complete list of old and new set commands. ``help set FOO''
7232 will give a longer description of the variable FOO. ``show'' will show
7233 all of the variable descriptions and their current settings.
7235 confirm on/off: Enables warning questions for operations that are
7236 hard to recover from, e.g. rerunning the program while
7237 it is already running. Default is ON.
7239 editing on/off: Enables EMACS style command line editing
7240 of input. Previous lines can be recalled with
7241 control-P, the current line can be edited with control-B,
7242 you can search for commands with control-R, etc.
7245 history filename NAME: NAME is where the gdb command history
7246 will be stored. The default is .gdb_history,
7247 or the value of the environment variable
7250 history size N: The size, in commands, of the command history. The
7251 default is 256, or the value of the environment variable
7254 history save on/off: If this value is set to ON, the history file will
7255 be saved after exiting gdb. If set to OFF, the
7256 file will not be saved. The default is OFF.
7258 history expansion on/off: If this value is set to ON, then csh-like
7259 history expansion will be performed on
7260 command line input. The default is OFF.
7262 radix N: Sets the default radix for input and output. It can be set
7263 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7264 in the current radix, so "set radix 10" is always a no-op.
7266 height N: This integer value is the number of lines on a page. Default
7267 is 24, the current `stty rows'' setting, or the ``li#''
7268 setting from the termcap entry matching the environment
7271 width N: This integer value is the number of characters on a line.
7272 Default is 80, the current `stty cols'' setting, or the ``co#''
7273 setting from the termcap entry matching the environment
7276 Note: ``set screensize'' is obsolete. Use ``set height'' and
7277 ``set width'' instead.
7279 print address on/off: Print memory addresses in various command displays,
7280 such as stack traces and structure values. Gdb looks
7281 more ``symbolic'' if you turn this off; it looks more
7282 ``machine level'' with it on. Default is ON.
7284 print array on/off: Prettyprint arrays. New convenient format! Default
7287 print demangle on/off: Print C++ symbols in "source" form if on,
7290 print asm-demangle on/off: Same, for assembler level printouts
7293 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7296 * Support for Epoch Environment.
7298 The epoch environment is a version of Emacs v18 with windowing. One
7299 new command, ``inspect'', is identical to ``print'', except that if you
7300 are running in the epoch environment, the value is printed in its own
7304 * Support for Shared Libraries
7306 GDB can now debug programs and core files that use SunOS shared libraries.
7307 Symbols from a shared library cannot be referenced
7308 before the shared library has been linked with the program (this
7309 happens after you type ``run'' and before the function main() is entered).
7310 At any time after this linking (including when examining core files
7311 from dynamically linked programs), gdb reads the symbols from each
7312 shared library when you type the ``sharedlibrary'' command.
7313 It can be abbreviated ``share''.
7315 sharedlibrary REGEXP: Load shared object library symbols for files
7316 matching a unix regular expression. No argument
7317 indicates to load symbols for all shared libraries.
7319 info sharedlibrary: Status of loaded shared libraries.
7324 A watchpoint stops execution of a program whenever the value of an
7325 expression changes. Checking for this slows down execution
7326 tremendously whenever you are in the scope of the expression, but is
7327 quite useful for catching tough ``bit-spreader'' or pointer misuse
7328 problems. Some machines such as the 386 have hardware for doing this
7329 more quickly, and future versions of gdb will use this hardware.
7331 watch EXP: Set a watchpoint (breakpoint) for an expression.
7333 info watchpoints: Information about your watchpoints.
7335 delete N: Deletes watchpoint number N (same as breakpoints).
7336 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7337 enable N: Re-enables watchpoint number N (same as breakpoints).
7340 * C++ multiple inheritance
7342 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7345 * C++ exception handling
7347 Gdb now supports limited C++ exception handling. Besides the existing
7348 ability to breakpoint on an exception handler, gdb can breakpoint on
7349 the raising of an exception (before the stack is peeled back to the
7352 catch FOO: If there is a FOO exception handler in the dynamic scope,
7353 set a breakpoint to catch exceptions which may be raised there.
7354 Multiple exceptions (``catch foo bar baz'') may be caught.
7356 info catch: Lists all exceptions which may be caught in the
7357 current stack frame.
7360 * Minor command changes
7362 The command ``call func (arg, arg, ...)'' now acts like the print
7363 command, except it does not print or save a value if the function's result
7364 is void. This is similar to dbx usage.
7366 The ``up'' and ``down'' commands now always print the frame they end up
7367 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7368 frames without printing.
7370 * New directory command
7372 'dir' now adds directories to the FRONT of the source search path.
7373 The path starts off empty. Source files that contain debug information
7374 about the directory in which they were compiled can be found even
7375 with an empty path; Sun CC and GCC include this information. If GDB can't
7376 find your source file in the current directory, type "dir .".
7378 * Configuring GDB for compilation
7380 For normal use, type ``./configure host''. See README or gdb.texinfo
7383 GDB now handles cross debugging. If you are remotely debugging between
7384 two different machines, type ``./configure host -target=targ''.
7385 Host is the machine where GDB will run; targ is the machine
7386 where the program that you are debugging will run.