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 convernience 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'.
32 set may-call-functions [on|off]
33 show may-call-functions
34 This controls whether GDB will attempt to call functions in
35 the program, such as with expressions in the print command. It
36 defaults to on. Calling functions in the program being debugged
37 can have undesired side effects. It is now possible to forbid
38 such function calls. If function calls are forbidden, GDB will throw
39 an error when a command (such as print expression) calls a function
42 *** Changes in GDB 8.3
44 * GDB and GDBserver now support access to additional registers on
45 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
48 * GDB now has experimental support for the compilation and injection of
49 C++ source code into the inferior. This beta release does not include
50 support for several language features, such as templates, constructors,
53 This feature requires GCC 7.1 or higher built with libcp1.so
56 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
57 can be passed using the '[ADDRESS]:PORT' notation, or the regular
58 'ADDRESS:PORT' method.
60 * DWARF index cache: GDB can now automatically save indices of DWARF
61 symbols on disk to speed up further loading of the same binaries.
63 * Ada task switching is now supported on aarch64-elf targets when
64 debugging a program using the Ravenscar Profile. For more information,
65 see the "Tasking Support when using the Ravenscar Profile" section
66 in the GDB user manual.
68 * GDB in batch mode now exits with status 1 if the last command to be
71 * The RISC-V target now supports target descriptions.
73 * System call catchpoints now support system call aliases on FreeBSD.
74 When the ABI of a system call changes in FreeBSD, this is
75 implemented by leaving a compatibility system call using the old ABI
76 at the existing number and allocating a new system call number for
77 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
78 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
79 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
80 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
81 so that a system call catchpoint for the 'kevent' system call will
82 catch invocations of both the 'kevent' and 'freebsd11_kevent'
83 binaries. This ensures that 'kevent' system calls are caught for
84 binaries using either the old or new ABIs.
86 * Terminal styling is now available for the CLI and the TUI. GNU
87 Source Highlight can additionally be used to provide styling of
88 source code snippets. See the "set style" commands, below, for more
91 * Removed support for old demangling styles arm, edg, gnu, hp and
96 set debug compile-cplus-types
97 show debug compile-cplus-types
98 Control the display of debug output about type conversion in the
99 C++ compile feature. Commands have no effect while compiliong
104 Control whether debug output about files/functions skipping is
107 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
108 Apply a command to some frames.
109 FLAG arguments allow to control what output to produce and how to handle
110 errors raised when applying COMMAND to a frame.
113 Apply a command to all threads (ignoring errors and empty output).
114 Shortcut for 'thread apply all -s COMMAND'.
117 Apply a command to all frames (ignoring errors and empty output).
118 Shortcut for 'frame apply all -s COMMAND'.
121 Apply a command to all frames of all threads (ignoring errors and empty
123 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
125 maint set dwarf unwinders (on|off)
126 maint show dwarf unwinders
127 Control whether DWARF unwinders can be used.
130 Display a list of open files for a process.
134 Changes to the "frame", "select-frame", and "info frame" CLI commands.
135 These commands all now take a frame specification which
136 is either a frame level, or one of the keywords 'level', 'address',
137 'function', or 'view' followed by a parameter. Selecting a frame by
138 address, or viewing a frame outside the current backtrace now
139 requires the use of a keyword. Selecting a frame by level is
140 unchanged. The MI comment "-stack-select-frame" is unchanged.
142 target remote FILENAME
143 target extended-remote FILENAME
144 If FILENAME is a Unix domain socket, GDB will attempt to connect
145 to this socket instead of opening FILENAME as a character device.
147 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
148 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
149 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
150 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
151 These commands can now print only the searched entities
152 matching the provided regexp(s), giving a condition
153 on the entity names or entity types. The flag -q disables
154 printing headers or informations messages.
160 These commands now determine the syntax for the shown entities
161 according to the language chosen by `set language'. In particular,
162 `set language auto' means to automatically choose the language of
165 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
166 The 'thread apply' command accepts new FLAG arguments.
167 FLAG arguments allow to control what output to produce and how to handle
168 errors raised when applying COMMAND to a thread.
170 set tui tab-width NCHARS
171 show tui tab-width NCHARS
172 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
174 set style enabled [on|off]
176 Enable or disable terminal styling. Styling is enabled by default
177 on most hosts, but disabled by default when in batch mode.
179 set style sources [on|off]
181 Enable or disable source code styling. Source code styling is
182 enabled by default, but only takes effect if styling in general is
183 enabled, and if GDB was linked with GNU Source Highlight.
185 set style filename foreground COLOR
186 set style filename background COLOR
187 set style filename intensity VALUE
188 Control the styling of file names.
190 set style function foreground COLOR
191 set style function background COLOR
192 set style function intensity VALUE
193 Control the styling of function names.
195 set style variable foreground COLOR
196 set style variable background COLOR
197 set style variable intensity VALUE
198 Control the styling of variable names.
200 set style address foreground COLOR
201 set style address background COLOR
202 set style address intensity VALUE
203 Control the styling of addresses.
207 ** The default version of the MI interpreter is now 3 (-i=mi3).
209 ** The '-data-disassemble' MI command now accepts an '-a' option to
210 disassemble the whole function surrounding the given program
211 counter value or function name. Support for this feature can be
212 verified by using the "-list-features" command, which should
213 contain "data-disassemble-a-option".
215 ** Command responses and notifications that include a frame now include
216 the frame's architecture in a new "arch" attribute.
218 ** The output of information about multi-location breakpoints (which is
219 syntactically incorrect in MI 2) has changed in MI 3. This affects
220 the following commands and events:
224 - =breakpoint-created
225 - =breakpoint-modified
227 The -fix-multi-location-breakpoint-output command can be used to enable
228 this behavior with previous MI versions.
230 * New native configurations
232 GNU/Linux/RISC-V riscv*-*-linux*
233 FreeBSD/riscv riscv*-*-freebsd*
237 GNU/Linux/RISC-V riscv*-*-linux*
239 CSKY GNU/LINUX csky*-*-linux
240 FreeBSD/riscv riscv*-*-freebsd*
242 GNU/Linux/OpenRISC or1k*-*-linux*
246 GDB no longer supports native debugging on versions of MS-Windows
251 ** GDB no longer supports Python versions less than 2.6.
253 ** The gdb.Inferior type has a new 'progspace' property, which is the program
254 space associated to that inferior.
256 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
257 of objfiles associated to that program space.
259 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
260 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
263 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
264 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
265 correct and did not work properly.
267 ** The gdb.Value type has a new constructor, which is used to construct a
268 gdb.Value from a Python buffer object and a gdb.Type.
274 Enable or disable the undefined behavior sanitizer. This is
275 disabled by default, but passing --enable-ubsan=yes or
276 --enable-ubsan=auto to configure will enable it. Enabling this can
277 cause a performance penalty. The undefined behavior sanitizer was
278 first introduced in GCC 4.9.
280 *** Changes in GDB 8.2
282 * The 'set disassembler-options' command now supports specifying options
285 * The 'symbol-file' command now accepts an '-o' option to add a relative
286 offset to all sections.
288 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
289 a relative offset to all sections, but it allows to override the load
290 address of individual sections using '-s'.
292 * The 'add-symbol-file' command no longer requires the second argument
293 (address of the text section).
295 * The endianness used with the 'set endian auto' mode in the absence of
296 an executable selected for debugging is now the last endianness chosen
297 either by one of the 'set endian big' and 'set endian little' commands
298 or by inferring from the last executable used, rather than the startup
301 * The pager now allows a "c" response, meaning to disable the pager
302 for the rest of the current command.
304 * The commands 'info variables/functions/types' now show the source line
305 numbers of symbol definitions when available.
307 * 'info proc' now works on running processes on FreeBSD systems and core
308 files created on FreeBSD systems.
310 * C expressions can now use _Alignof, and C++ expressions can now use
313 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
314 the vector length while the process is running.
320 Control display of debugging info regarding the FreeBSD native target.
322 set|show varsize-limit
323 This new setting allows the user to control the maximum size of Ada
324 objects being printed when those objects have a variable type,
325 instead of that maximum size being hardcoded to 65536 bytes.
327 set|show record btrace cpu
328 Controls the processor to be used for enabling errata workarounds for
331 maint check libthread-db
332 Run integrity checks on the current inferior's thread debugging
335 maint set check-libthread-db (on|off)
336 maint show check-libthread-db
337 Control whether to run integrity checks on inferior specific thread
338 debugging libraries as they are loaded. The default is not to
343 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
345 ** The commands attached to a breakpoint can be set by assigning to
346 the breakpoint's "commands" field.
348 ** gdb.execute can now execute multi-line gdb commands.
350 ** The new functions gdb.convenience_variable and
351 gdb.set_convenience_variable can be used to get and set the value
352 of convenience variables.
354 ** A gdb.Parameter will no longer print the "set" help text on an
355 ordinary "set"; instead by default a "set" will be silent unless
356 the get_set_string method returns a non-empty string.
360 RiscV ELF riscv*-*-elf
362 * Removed targets and native configurations
364 m88k running OpenBSD m88*-*-openbsd*
365 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
366 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
367 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
369 * Aarch64/Linux hardware watchpoints improvements
371 Hardware watchpoints on unaligned addresses are now properly
372 supported when running Linux kernel 4.10 or higher: read and access
373 watchpoints are no longer spuriously missed, and all watchpoints
374 lengths between 1 and 8 bytes are supported. On older kernels,
375 watchpoints set on unaligned addresses are no longer missed, with
376 the tradeoff that there is a possibility of false hits being
381 --enable-codesign=CERT
382 This can be used to invoke "codesign -s CERT" after building gdb.
383 This option is useful on macOS, where code signing is required for
384 gdb to work properly.
386 --disable-gdbcli has been removed
387 This is now silently accepted, but does nothing.
389 *** Changes in GDB 8.1
391 * GDB now supports dynamically creating arbitrary register groups specified
392 in XML target descriptions. This allows for finer grain grouping of
393 registers on systems with a large amount of registers.
395 * The 'ptype' command now accepts a '/o' flag, which prints the
396 offsets and sizes of fields in a struct, like the pahole(1) tool.
398 * New "--readnever" command line option instructs GDB to not read each
399 symbol file's symbolic debug information. This makes startup faster
400 but at the expense of not being able to perform symbolic debugging.
401 This option is intended for use cases where symbolic debugging will
402 not be used, e.g., when you only need to dump the debuggee's core.
404 * GDB now uses the GNU MPFR library, if available, to emulate target
405 floating-point arithmetic during expression evaluation when the target
406 uses different floating-point formats than the host. At least version
407 3.1 of GNU MPFR is required.
409 * GDB now supports access to the guarded-storage-control registers and the
410 software-based guarded-storage broadcast control registers on IBM z14.
412 * On Unix systems, GDB now supports transmitting environment variables
413 that are to be set or unset to GDBserver. These variables will
414 affect the environment to be passed to the remote inferior.
416 To inform GDB of environment variables that are to be transmitted to
417 GDBserver, use the "set environment" command. Only user set
418 environment variables are sent to GDBserver.
420 To inform GDB of environment variables that are to be unset before
421 the remote inferior is started by the GDBserver, use the "unset
422 environment" command.
424 * Completion improvements
426 ** GDB can now complete function parameters in linespecs and
427 explicit locations without quoting. When setting breakpoints,
428 quoting around functions names to help with TAB-completion is
429 generally no longer necessary. For example, this now completes
432 (gdb) b function(in[TAB]
433 (gdb) b function(int)
435 Related, GDB is no longer confused with completing functions in
436 C++ anonymous namespaces:
439 (gdb) b (anonymous namespace)::[TAB][TAB]
440 (anonymous namespace)::a_function()
441 (anonymous namespace)::b_function()
443 ** GDB now has much improved linespec and explicit locations TAB
444 completion support, that better understands what you're
445 completing and offers better suggestions. For example, GDB no
446 longer offers data symbols as possible completions when you're
447 setting a breakpoint.
449 ** GDB now TAB-completes label symbol names.
451 ** The "complete" command now mimics TAB completion accurately.
453 * New command line options (gcore)
456 Dump all memory mappings.
458 * Breakpoints on C++ functions are now set on all scopes by default
460 By default, breakpoints on functions/methods are now interpreted as
461 specifying all functions with the given name ignoring missing
462 leading scopes (namespaces and classes).
464 For example, assuming a C++ program with symbols named:
469 both commands "break func()" and "break B::func()" set a breakpoint
472 You can use the new flag "-qualified" to override this. This makes
473 GDB interpret the specified function name as a complete
474 fully-qualified name instead. For example, using the same C++
475 program, the "break -q B::func" command sets a breakpoint on
476 "B::func", only. A parameter has been added to the Python
477 gdb.Breakpoint constructor to achieve the same result when creating
478 a breakpoint from Python.
480 * Breakpoints on functions marked with C++ ABI tags
482 GDB can now set breakpoints on functions marked with C++ ABI tags
483 (e.g., [abi:cxx11]). See here for a description of ABI tags:
484 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
486 Functions with a C++11 abi tag are demangled/displayed like this:
488 function[abi:cxx11](int)
491 You can now set a breakpoint on such functions simply as if they had
494 (gdb) b function(int)
496 Or if you need to disambiguate between tags, like:
498 (gdb) b function[abi:other_tag](int)
500 Tab completion was adjusted accordingly as well.
504 ** New events gdb.new_inferior, gdb.inferior_deleted, and
505 gdb.new_thread are emitted. See the manual for further
506 description of these.
508 ** A new function, "gdb.rbreak" has been added to the Python API.
509 This function allows the setting of a large number of breakpoints
510 via a regex pattern in Python. See the manual for further details.
512 ** Python breakpoints can now accept explicit locations. See the
513 manual for a further description of this feature.
516 * New features in the GDB remote stub, GDBserver
518 ** GDBserver is now able to start inferior processes with a
519 specified initial working directory.
521 The user can set the desired working directory to be used from
522 GDB using the new "set cwd" command.
524 ** New "--selftest" command line option runs some GDBserver self
525 tests. These self tests are disabled in releases.
527 ** On Unix systems, GDBserver now does globbing expansion and variable
528 substitution in inferior command line arguments.
530 This is done by starting inferiors using a shell, like GDB does.
531 See "set startup-with-shell" in the user manual for how to disable
532 this from GDB when using "target extended-remote". When using
533 "target remote", you can disable the startup with shell by using the
534 new "--no-startup-with-shell" GDBserver command line option.
536 ** On Unix systems, GDBserver now supports receiving environment
537 variables that are to be set or unset from GDB. These variables
538 will affect the environment to be passed to the inferior.
540 * When catching an Ada exception raised with a message, GDB now prints
541 the message in the catchpoint hit notification. In GDB/MI mode, that
542 information is provided as an extra field named "exception-message"
543 in the *stopped notification.
545 * Trait objects can now be inspected When debugging Rust code. This
546 requires compiler support which will appear in Rust 1.24.
550 QEnvironmentHexEncoded
551 Inform GDBserver of an environment variable that is to be passed to
552 the inferior when starting it.
555 Inform GDBserver of an environment variable that is to be unset
556 before starting the remote inferior.
559 Inform GDBserver that the environment should be reset (i.e.,
560 user-set environment variables should be unset).
563 Indicates whether the inferior must be started with a shell or not.
566 Tell GDBserver that the inferior to be started should use a specific
569 * The "maintenance print c-tdesc" command now takes an optional
570 argument which is the file name of XML target description.
572 * The "maintenance selftest" command now takes an optional argument to
573 filter the tests to be run.
575 * The "enable", and "disable" commands now accept a range of
576 breakpoint locations, e.g. "enable 1.3-5".
581 Set and show the current working directory for the inferior.
584 Set and show compilation command used for compiling and injecting code
585 with the 'compile' commands.
587 set debug separate-debug-file
588 show debug separate-debug-file
589 Control the display of debug output about separate debug file search.
591 set dump-excluded-mappings
592 show dump-excluded-mappings
593 Control whether mappings marked with the VM_DONTDUMP flag should be
594 dumped when generating a core file.
597 List the registered selftests.
600 Start the debugged program stopping at the first instruction.
603 Control display of debugging messages related to OpenRISC targets.
605 set|show print type nested-type-limit
606 Set and show the limit of nesting level for nested types that the
607 type printer will show.
609 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
612 * Safer/improved support for debugging with no debug info
614 GDB no longer assumes functions with no debug information return
617 This means that GDB now refuses to call such functions unless you
618 tell it the function's type, by either casting the call to the
619 declared return type, or by casting the function to a function
620 pointer of the right type, and calling that:
622 (gdb) p getenv ("PATH")
623 'getenv' has unknown return type; cast the call to its declared return type
624 (gdb) p (char *) getenv ("PATH")
625 $1 = 0x7fffffffe "/usr/local/bin:/"...
626 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
627 $2 = 0x7fffffffe "/usr/local/bin:/"...
629 Similarly, GDB no longer assumes that global variables with no debug
630 info have type 'int', and refuses to print the variable's value
631 unless you tell it the variable's type:
634 'var' has unknown type; cast it to its declared type
638 * New native configurations
640 FreeBSD/aarch64 aarch64*-*-freebsd*
641 FreeBSD/arm arm*-*-freebsd*
645 FreeBSD/aarch64 aarch64*-*-freebsd*
646 FreeBSD/arm arm*-*-freebsd*
647 OpenRISC ELF or1k*-*-elf
649 * Removed targets and native configurations
651 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
653 *** Changes in GDB 8.0
655 * GDB now supports access to the PKU register on GNU/Linux. The register is
656 added by the Memory Protection Keys for Userspace feature which will be
657 available in future Intel CPUs.
659 * GDB now supports C++11 rvalue references.
663 ** New functions to start, stop and access a running btrace recording.
664 ** Rvalue references are now supported in gdb.Type.
666 * GDB now supports recording and replaying rdrand and rdseed Intel 64
669 * Building GDB and GDBserver now requires a C++11 compiler.
671 For example, GCC 4.8 or later.
673 It is no longer possible to build GDB or GDBserver with a C
674 compiler. The --disable-build-with-cxx configure option has been
677 * Building GDB and GDBserver now requires GNU make >= 3.81.
679 It is no longer supported to build GDB or GDBserver with another
680 implementation of the make program or an earlier version of GNU make.
682 * Native debugging on MS-Windows supports command-line redirection
684 Command-line arguments used for starting programs on MS-Windows can
685 now include redirection symbols supported by native Windows shells,
686 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
687 as "run", "start", and "set args", as well as the corresponding MI
690 * Support for thread names on MS-Windows.
692 GDB now catches and handles the special exception that programs
693 running on MS-Windows use to assign names to threads in the
696 * Support for Java programs compiled with gcj has been removed.
698 * User commands now accept an unlimited number of arguments.
699 Previously, only up to 10 was accepted.
701 * The "eval" command now expands user-defined command arguments.
703 This makes it easier to process a variable number of arguments:
708 eval "print $arg%d", $i
713 * Target descriptions can now describe registers for sparc32 and sparc64.
715 * GDB now supports DWARF version 5 (debug information format).
716 Its .debug_names index is not yet supported.
718 * New native configurations
720 FreeBSD/mips mips*-*-freebsd
724 Synopsys ARC arc*-*-elf32
725 FreeBSD/mips mips*-*-freebsd
727 * Removed targets and native configurations
729 Alpha running FreeBSD alpha*-*-freebsd*
730 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
735 Erases all the flash memory regions reported by the target.
737 maint print arc arc-instruction address
738 Print internal disassembler information about instruction at a given address.
742 set disassembler-options
743 show disassembler-options
744 Controls the passing of target specific information to the disassembler.
745 If it is necessary to specify more than one disassembler option then
746 multiple options can be placed together into a comma separated list.
747 The default value is the empty string. Currently, the only supported
748 targets are ARM, PowerPC and S/390.
753 Erases all the flash memory regions reported by the target. This is
754 equivalent to the CLI command flash-erase.
756 -file-list-shared-libraries
757 List the shared libraries in the program. This is
758 equivalent to the CLI command "info shared".
761 Catchpoints stopping the program when Ada exceptions are
762 handled. This is equivalent to the CLI command "catch handlers".
764 *** Changes in GDB 7.12
766 * GDB and GDBserver now build with a C++ compiler by default.
768 The --enable-build-with-cxx configure option is now enabled by
769 default. One must now explicitly configure with
770 --disable-build-with-cxx in order to build with a C compiler. This
771 option will be removed in a future release.
773 * GDBserver now supports recording btrace without maintaining an active
776 * GDB now supports a negative repeat count in the 'x' command to examine
777 memory backward from the given address. For example:
780 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
781 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
782 (gdb) x/-5i 0x0000000000400580
783 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
784 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
785 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
786 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
787 0x40057b <main(int, char**)+25>:
788 callq 0x400536 <Func1(int, char const*)>
790 * Fortran: Support structures with fields of dynamic types and
791 arrays of dynamic types.
793 * The symbol dumping maintenance commands have new syntax.
794 maint print symbols [-pc address] [--] [filename]
795 maint print symbols [-objfile objfile] [-source source] [--] [filename]
796 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
797 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
798 maint print msymbols [-objfile objfile] [--] [filename]
800 * GDB now supports multibit bitfields and enums in target register
803 * New Python-based convenience function $_as_string(val), which returns
804 the textual representation of a value. This function is especially
805 useful to obtain the text label of an enum value.
807 * Intel MPX bound violation handling.
809 Segmentation faults caused by a Intel MPX boundary violation
810 now display the kind of violation (upper or lower), the memory
811 address accessed and the memory bounds, along with the usual
812 signal received and code location.
816 Program received signal SIGSEGV, Segmentation fault
817 Upper bound violation while accessing address 0x7fffffffc3b3
818 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
819 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
821 * Rust language support.
822 GDB now supports debugging programs written in the Rust programming
823 language. See https://www.rust-lang.org/ for more information about
826 * Support for running interpreters on specified input/output devices
828 GDB now supports a new mechanism that allows frontends to provide
829 fully featured GDB console views, as a better alternative to
830 building such views on top of the "-interpreter-exec console"
831 command. See the new "new-ui" command below. With that command,
832 frontends can now start GDB in the traditional command-line mode
833 running in an embedded terminal emulator widget, and create a
834 separate MI interpreter running on a specified i/o device. In this
835 way, GDB handles line editing, history, tab completion, etc. in the
836 console all by itself, and the GUI uses the separate MI interpreter
837 for its own control and synchronization, invisible to the command
840 * The "catch syscall" command catches groups of related syscalls.
842 The "catch syscall" command now supports catching a group of related
843 syscalls using the 'group:' or 'g:' prefix.
848 skip -gfile file-glob-pattern
849 skip -function function
850 skip -rfunction regular-expression
851 A generalized form of the skip command, with new support for
852 glob-style file names and regular expressions for function names.
853 Additionally, a file spec and a function spec may now be combined.
855 maint info line-table REGEXP
856 Display the contents of GDB's internal line table data struture.
859 Run any GDB unit tests that were compiled in.
862 Start a new user interface instance running INTERP as interpreter,
863 using the TTY file for input/output.
867 ** gdb.Breakpoint objects have a new attribute "pending", which
868 indicates whether the breakpoint is pending.
869 ** Three new breakpoint-related events have been added:
870 gdb.breakpoint_created, gdb.breakpoint_modified, and
871 gdb.breakpoint_deleted.
874 Signal ("set") the given MS-Windows event object. This is used in
875 conjunction with the Windows JIT debugging (AeDebug) support, where
876 the OS suspends a crashing process until a debugger can attach to
877 it. Resuming the crashing process, in order to debug it, is done by
880 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
881 was added in GDBserver, including JIT compiling fast tracepoint's
882 conditional expression bytecode into native code.
884 * Support for various remote target protocols and ROM monitors has
887 target m32rsdi Remote M32R debugging over SDI
888 target mips MIPS remote debugging protocol
889 target pmon PMON ROM monitor
890 target ddb NEC's DDB variant of PMON for Vr4300
891 target rockhopper NEC RockHopper variant of PMON
892 target lsi LSI variant of PMO
894 * Support for tracepoints and fast tracepoints on powerpc-linux,
895 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
896 including JIT compiling fast tracepoint's conditional expression
897 bytecode into native code.
899 * MI async record =record-started now includes the method and format used for
900 recording. For example:
902 =record-started,thread-group="i1",method="btrace",format="bts"
904 * MI async record =thread-selected now includes the frame field. For example:
906 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
910 Andes NDS32 nds32*-*-elf
912 *** Changes in GDB 7.11
914 * GDB now supports debugging kernel-based threads on FreeBSD.
916 * Per-inferior thread numbers
918 Thread numbers are now per inferior instead of global. If you're
919 debugging multiple inferiors, GDB displays thread IDs using a
920 qualified INF_NUM.THR_NUM form. For example:
924 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
925 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
926 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
927 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
929 As consequence, thread numbers as visible in the $_thread
930 convenience variable and in Python's InferiorThread.num attribute
931 are no longer unique between inferiors.
933 GDB now maintains a second thread ID per thread, referred to as the
934 global thread ID, which is the new equivalent of thread numbers in
935 previous releases. See also $_gthread below.
937 For backwards compatibility, MI's thread IDs always refer to global
940 * Commands that accept thread IDs now accept the qualified
941 INF_NUM.THR_NUM form as well. For example:
944 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
947 * In commands that accept a list of thread IDs, you can now refer to
948 all threads of an inferior using a star wildcard. GDB accepts
949 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
950 refer to all threads of the current inferior. For example, "info
953 * You can use "info threads -gid" to display the global thread ID of
956 * The new convenience variable $_gthread holds the global number of
959 * The new convenience variable $_inferior holds the number of the
962 * GDB now displays the ID and name of the thread that hit a breakpoint
963 or received a signal, if your program is multi-threaded. For
966 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
967 Thread 1 "main" received signal SIGINT, Interrupt.
969 * Record btrace now supports non-stop mode.
971 * Support for tracepoints on aarch64-linux was added in GDBserver.
973 * The 'record instruction-history' command now indicates speculative execution
974 when using the Intel Processor Trace recording format.
976 * GDB now allows users to specify explicit locations, bypassing
977 the linespec parser. This feature is also available to GDB/MI
980 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
981 GDB now is able to debug both AArch64 applications and ARM applications
984 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
985 including JIT compiling fast tracepoint's conditional expression bytecode
988 * GDB now supports displaced stepping on AArch64 GNU/Linux.
990 * "info threads", "info inferiors", "info display", "info checkpoints"
991 and "maint info program-spaces" now list the corresponding items in
992 ascending ID order, for consistency with all other "info" commands.
994 * In Ada, the overloads selection menu has been enhanced to display the
995 parameter types and the return types for the matching overloaded subprograms.
999 maint set target-non-stop (on|off|auto)
1000 maint show target-non-stop
1001 Control whether GDB targets always operate in non-stop mode even if
1002 "set non-stop" is "off". The default is "auto", meaning non-stop
1003 mode is enabled if supported by the target.
1005 maint set bfd-sharing
1006 maint show bfd-sharing
1007 Control the reuse of bfd objects.
1010 show debug bfd-cache
1011 Control display of debugging info regarding bfd caching.
1015 Control display of debugging info regarding FreeBSD threads.
1017 set remote multiprocess-extensions-packet
1018 show remote multiprocess-extensions-packet
1019 Set/show the use of the remote protocol multiprocess extensions.
1021 set remote thread-events
1022 show remote thread-events
1023 Set/show the use of thread create/exit events.
1025 set ada print-signatures on|off
1026 show ada print-signatures"
1027 Control whether parameter types and return types are displayed in overloads
1028 selection menus. It is activaled (@code{on}) by default.
1032 Controls the maximum size of memory, in bytes, that GDB will
1033 allocate for value contents. Prevents incorrect programs from
1034 causing GDB to allocate overly large buffers. Default is 64k.
1036 * The "disassemble" command accepts a new modifier: /s.
1037 It prints mixed source+disassembly like /m with two differences:
1038 - disassembled instructions are now printed in program order, and
1039 - and source for all relevant files is now printed.
1040 The "/m" option is now considered deprecated: its "source-centric"
1041 output hasn't proved useful in practice.
1043 * The "record instruction-history" command accepts a new modifier: /s.
1044 It behaves exactly like /m and prints mixed source+disassembly.
1046 * The "set scheduler-locking" command supports a new mode "replay".
1047 It behaves like "off" in record mode and like "on" in replay mode.
1049 * Support for various ROM monitors has been removed:
1051 target dbug dBUG ROM monitor for Motorola ColdFire
1052 target picobug Motorola picobug monitor
1053 target dink32 DINK32 ROM monitor for PowerPC
1054 target m32r Renesas M32R/D ROM monitor
1055 target mon2000 mon2000 ROM monitor
1056 target ppcbug PPCBUG ROM monitor for PowerPC
1058 * Support for reading/writing memory and extracting values on architectures
1059 whose memory is addressable in units of any integral multiple of 8 bits.
1062 Allows to break when an Ada exception is handled.
1064 * New remote packets
1067 Indicates that an exec system call was executed.
1069 exec-events feature in qSupported
1070 The qSupported packet allows GDB to request support for exec
1071 events using the new 'gdbfeature' exec-event, and the qSupported
1072 response can contain the corresponding 'stubfeature'. Set and
1073 show commands can be used to display whether these features are enabled.
1076 Equivalent to interrupting with the ^C character, but works in
1079 thread created stop reason (T05 create:...)
1080 Indicates that the thread was just created and is stopped at entry.
1082 thread exit stop reply (w exitcode;tid)
1083 Indicates that the thread has terminated.
1086 Enables/disables thread create and exit event reporting. For
1087 example, this is used in non-stop mode when GDB stops a set of
1088 threads and synchronously waits for the their corresponding stop
1089 replies. Without exit events, if one of the threads exits, GDB
1090 would hang forever not knowing that it should no longer expect a
1091 stop for that same thread.
1094 Indicates that there are no resumed threads left in the target (all
1095 threads are stopped). The remote stub reports support for this stop
1096 reply to GDB's qSupported query.
1099 Enables/disables catching syscalls from the inferior process.
1100 The remote stub reports support for this packet to GDB's qSupported query.
1102 syscall_entry stop reason
1103 Indicates that a syscall was just called.
1105 syscall_return stop reason
1106 Indicates that a syscall just returned.
1108 * Extended-remote exec events
1110 ** GDB now has support for exec events on extended-remote Linux targets.
1111 For such targets with Linux kernels 2.5.46 and later, this enables
1112 follow-exec-mode and exec catchpoints.
1114 set remote exec-event-feature-packet
1115 show remote exec-event-feature-packet
1116 Set/show the use of the remote exec event feature.
1118 * Thread names in remote protocol
1120 The reply to qXfer:threads:read may now include a name attribute for each
1123 * Target remote mode fork and exec events
1125 ** GDB now has support for fork and exec events on target remote mode
1126 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1127 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1128 fork and exec catchpoints.
1130 * Remote syscall events
1132 ** GDB now has support for catch syscall on remote Linux targets,
1133 currently enabled on x86/x86_64 architectures.
1135 set remote catch-syscall-packet
1136 show remote catch-syscall-packet
1137 Set/show the use of the remote catch syscall feature.
1141 ** The -var-set-format command now accepts the zero-hexadecimal
1142 format. It outputs data in hexadecimal format with zero-padding on the
1147 ** gdb.InferiorThread objects have a new attribute "global_num",
1148 which refers to the thread's global thread ID. The existing
1149 "num" attribute now refers to the thread's per-inferior number.
1150 See "Per-inferior thread numbers" above.
1151 ** gdb.InferiorThread objects have a new attribute "inferior", which
1152 is the Inferior object the thread belongs to.
1154 *** Changes in GDB 7.10
1156 * Support for process record-replay and reverse debugging on aarch64*-linux*
1157 targets has been added. GDB now supports recording of A64 instruction set
1158 including advance SIMD instructions.
1160 * Support for Sun's version of the "stabs" debug file format has been removed.
1162 * GDB now honors the content of the file /proc/PID/coredump_filter
1163 (PID is the process ID) on GNU/Linux systems. This file can be used
1164 to specify the types of memory mappings that will be included in a
1165 corefile. For more information, please refer to the manual page of
1166 "core(5)". GDB also has a new command: "set use-coredump-filter
1167 on|off". It allows to set whether GDB will read the content of the
1168 /proc/PID/coredump_filter file when generating a corefile.
1170 * The "info os" command on GNU/Linux can now display information on
1172 "info os cpus" Listing of all cpus/cores on the system
1174 * GDB has two new commands: "set serial parity odd|even|none" and
1175 "show serial parity". These allows to set or show parity for the
1178 * The "info source" command now displays the producer string if it was
1179 present in the debug info. This typically includes the compiler version
1180 and may include things like its command line arguments.
1182 * The "info dll", an alias of the "info sharedlibrary" command,
1183 is now available on all platforms.
1185 * Directory names supplied to the "set sysroot" commands may be
1186 prefixed with "target:" to tell GDB to access shared libraries from
1187 the target system, be it local or remote. This replaces the prefix
1188 "remote:". The default sysroot has been changed from "" to
1189 "target:". "remote:" is automatically converted to "target:" for
1190 backward compatibility.
1192 * The system root specified by "set sysroot" will be prepended to the
1193 filename of the main executable (if reported to GDB as absolute by
1194 the operating system) when starting processes remotely, and when
1195 attaching to already-running local or remote processes.
1197 * GDB now supports automatic location and retrieval of executable
1198 files from remote targets. Remote debugging can now be initiated
1199 using only a "target remote" or "target extended-remote" command
1200 (no "set sysroot" or "file" commands are required). See "New remote
1203 * The "dump" command now supports verilog hex format.
1205 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1207 * On GNU/Linux, GDB and gdbserver are now able to access executable
1208 and shared library files without a "set sysroot" command when
1209 attaching to processes running in different mount namespaces from
1210 the debugger. This makes it possible to attach to processes in
1211 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1212 See "New remote packets" below.
1214 * The "tui reg" command now provides completion for all of the
1215 available register groups, including target specific groups.
1217 * The HISTSIZE environment variable is no longer read when determining
1218 the size of GDB's command history. GDB now instead reads the dedicated
1219 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1220 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1225 ** Memory ports can now be unbuffered.
1229 ** gdb.Objfile objects have a new attribute "username",
1230 which is the name of the objfile as specified by the user,
1231 without, for example, resolving symlinks.
1232 ** You can now write frame unwinders in Python.
1233 ** gdb.Type objects have a new method "optimized_out",
1234 returning optimized out gdb.Value instance of this type.
1235 ** gdb.Value objects have new methods "reference_value" and
1236 "const_value" which return a reference to the value and a
1237 "const" version of the value respectively.
1241 maint print symbol-cache
1242 Print the contents of the symbol cache.
1244 maint print symbol-cache-statistics
1245 Print statistics of symbol cache usage.
1247 maint flush-symbol-cache
1248 Flush the contents of the symbol cache.
1252 Start branch trace recording using Branch Trace Store (BTS) format.
1255 Evaluate expression by using the compiler and print result.
1259 Explicit commands for enabling and disabling tui mode.
1262 set mpx bound on i386 and amd64
1263 Support for bound table investigation on Intel MPX enabled applications.
1267 Start branch trace recording using Intel Processor Trace format.
1270 Print information about branch tracing internals.
1272 maint btrace packet-history
1273 Print the raw branch tracing data.
1275 maint btrace clear-packet-history
1276 Discard the stored raw branch tracing data.
1279 Discard all branch tracing data. It will be fetched and processed
1280 anew by the next "record" command.
1285 Renamed from "set debug dwarf2-die".
1286 show debug dwarf-die
1287 Renamed from "show debug dwarf2-die".
1289 set debug dwarf-read
1290 Renamed from "set debug dwarf2-read".
1291 show debug dwarf-read
1292 Renamed from "show debug dwarf2-read".
1294 maint set dwarf always-disassemble
1295 Renamed from "maint set dwarf2 always-disassemble".
1296 maint show dwarf always-disassemble
1297 Renamed from "maint show dwarf2 always-disassemble".
1299 maint set dwarf max-cache-age
1300 Renamed from "maint set dwarf2 max-cache-age".
1301 maint show dwarf max-cache-age
1302 Renamed from "maint show dwarf2 max-cache-age".
1304 set debug dwarf-line
1305 show debug dwarf-line
1306 Control display of debugging info regarding DWARF line processing.
1309 show max-completions
1310 Set the maximum number of candidates to be considered during
1311 completion. The default value is 200. This limit allows GDB
1312 to avoid generating large completion lists, the computation of
1313 which can cause the debugger to become temporarily unresponsive.
1315 set history remove-duplicates
1316 show history remove-duplicates
1317 Control the removal of duplicate history entries.
1319 maint set symbol-cache-size
1320 maint show symbol-cache-size
1321 Control the size of the symbol cache.
1323 set|show record btrace bts buffer-size
1324 Set and show the size of the ring buffer used for branch tracing in
1326 The obtained size may differ from the requested size. Use "info
1327 record" to see the obtained buffer size.
1329 set debug linux-namespaces
1330 show debug linux-namespaces
1331 Control display of debugging info regarding Linux namespaces.
1333 set|show record btrace pt buffer-size
1334 Set and show the size of the ring buffer used for branch tracing in
1335 Intel Processor Trace format.
1336 The obtained size may differ from the requested size. Use "info
1337 record" to see the obtained buffer size.
1339 maint set|show btrace pt skip-pad
1340 Set and show whether PAD packets are skipped when computing the
1343 * The command 'thread apply all' can now support new option '-ascending'
1344 to call its specified command for all threads in ascending order.
1346 * Python/Guile scripting
1348 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1349 special section named `.debug_gdb_scripts'.
1351 * New remote packets
1353 qXfer:btrace-conf:read
1354 Return the branch trace configuration for the current thread.
1356 Qbtrace-conf:bts:size
1357 Set the requested ring buffer size for branch tracing in BTS format.
1360 Enable Intel Procesor Trace-based branch tracing for the current
1361 process. The remote stub reports support for this packet to GDB's
1364 Qbtrace-conf:pt:size
1365 Set the requested ring buffer size for branch tracing in Intel Processor
1369 Indicates a memory breakpoint instruction was executed, irrespective
1370 of whether it was GDB that planted the breakpoint or the breakpoint
1371 is hardcoded in the program. This is required for correct non-stop
1375 Indicates the target stopped for a hardware breakpoint. This is
1376 required for correct non-stop mode operation.
1379 Return information about files on the remote system.
1381 qXfer:exec-file:read
1382 Return the full absolute name of the file that was executed to
1383 create a process running on the remote system.
1386 Select the filesystem on which vFile: operations with filename
1387 arguments will operate. This is required for GDB to be able to
1388 access files on remote targets where the remote stub does not
1389 share a common filesystem with the inferior(s).
1392 Indicates that a fork system call was executed.
1395 Indicates that a vfork system call was executed.
1397 vforkdone stop reason
1398 Indicates that a vfork child of the specified process has executed
1399 an exec or exit, allowing the vfork parent to resume execution.
1401 fork-events and vfork-events features in qSupported
1402 The qSupported packet allows GDB to request support for fork and
1403 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1404 and the qSupported response can contain the corresponding
1405 'stubfeatures'. Set and show commands can be used to display
1406 whether these features are enabled.
1408 * Extended-remote fork events
1410 ** GDB now has support for fork events on extended-remote Linux
1411 targets. For targets with Linux kernels 2.5.60 and later, this
1412 enables follow-fork-mode and detach-on-fork for both fork and
1413 vfork, as well as fork and vfork catchpoints.
1415 * The info record command now shows the recording format and the
1416 branch tracing configuration for the current thread when using
1417 the btrace record target.
1418 For the BTS format, it shows the ring buffer size.
1420 * GDB now has support for DTrace USDT (Userland Static Defined
1421 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1423 * GDB now supports access to vector registers on S/390 GNU/Linux
1426 * Removed command line options
1428 -xdb HP-UX XDB compatibility mode.
1430 * Removed targets and native configurations
1432 HP/PA running HP-UX hppa*-*-hpux*
1433 Itanium running HP-UX ia64-*-hpux*
1435 * New configure options
1438 This configure option allows the user to build GDB with support for
1439 Intel Processor Trace (default: auto). This requires libipt.
1441 --with-libipt-prefix=PATH
1442 Specify the path to the version of libipt that GDB should use.
1443 $PATH/include should contain the intel-pt.h header and
1444 $PATH/lib should contain the libipt.so library.
1446 *** Changes in GDB 7.9.1
1450 ** Xmethods can now specify a result type.
1452 *** Changes in GDB 7.9
1454 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1458 ** You can now access frame registers from Python scripts.
1459 ** New attribute 'producer' for gdb.Symtab objects.
1460 ** gdb.Objfile objects have a new attribute "progspace",
1461 which is the gdb.Progspace object of the containing program space.
1462 ** gdb.Objfile objects have a new attribute "owner".
1463 ** gdb.Objfile objects have a new attribute "build_id",
1464 which is the build ID generated when the file was built.
1465 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1466 ** A new event "gdb.clear_objfiles" has been added, triggered when
1467 selecting a new file to debug.
1468 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1469 ** New function gdb.lookup_objfile.
1471 New events which are triggered when GDB modifies the state of the
1474 ** gdb.events.inferior_call_pre: Function call is about to be made.
1475 ** gdb.events.inferior_call_post: Function call has just been made.
1476 ** gdb.events.memory_changed: A memory location has been altered.
1477 ** gdb.events.register_changed: A register has been altered.
1479 * New Python-based convenience functions:
1481 ** $_caller_is(name [, number_of_frames])
1482 ** $_caller_matches(regexp [, number_of_frames])
1483 ** $_any_caller_is(name [, number_of_frames])
1484 ** $_any_caller_matches(regexp [, number_of_frames])
1486 * GDB now supports the compilation and injection of source code into
1487 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1488 to compile the source code to object code, and if successful, inject
1489 and execute that code within the current context of the inferior.
1490 Currently the C language is supported. The commands used to
1491 interface with this new feature are:
1493 compile code [-raw|-r] [--] [source code]
1494 compile file [-raw|-r] filename
1498 demangle [-l language] [--] name
1499 Demangle "name" in the specified language, or the current language
1500 if elided. This command is renamed from the "maint demangle" command.
1501 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1502 as "maint demangler-warning".
1504 queue-signal signal-name-or-number
1505 Queue a signal to be delivered to the thread when it is resumed.
1507 add-auto-load-scripts-directory directory
1508 Add entries to the list of directories from which to load auto-loaded
1511 maint print user-registers
1512 List all currently available "user" registers.
1514 compile code [-r|-raw] [--] [source code]
1515 Compile, inject, and execute in the inferior the executable object
1516 code produced by compiling the provided source code.
1518 compile file [-r|-raw] filename
1519 Compile and inject into the inferior the executable object code
1520 produced by compiling the source code stored in the filename
1523 * On resume, GDB now always passes the signal the program had stopped
1524 for to the thread the signal was sent to, even if the user changed
1525 threads before resuming. Previously GDB would often (but not
1526 always) deliver the signal to the thread that happens to be current
1529 * Conversely, the "signal" command now consistently delivers the
1530 requested signal to the current thread. GDB now asks for
1531 confirmation if the program had stopped for a signal and the user
1532 switched threads meanwhile.
1534 * "breakpoint always-inserted" modes "off" and "auto" merged.
1536 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1537 won't remove breakpoints from the target until all threads stop,
1538 even in non-stop mode. The "auto" mode has been removed, and "off"
1539 is now the default mode.
1543 set debug symbol-lookup
1544 show debug symbol-lookup
1545 Control display of debugging info regarding symbol lookup.
1549 ** The -list-thread-groups command outputs an exit-code field for
1550 inferiors that have exited.
1554 MIPS SDE mips*-sde*-elf*
1558 Support for these obsolete configurations has been removed.
1560 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1561 SGI Irix-5.x mips-*-irix5*
1562 SGI Irix-6.x mips-*-irix6*
1563 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1564 VAX running Ultrix vax-*-ultrix*
1566 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1567 and "assf"), have been removed. Use the "sharedlibrary" command, or
1568 its alias "share", instead.
1570 *** Changes in GDB 7.8
1572 * New command line options
1575 This is an alias for the --data-directory option.
1577 * GDB supports printing and modifying of variable length automatic arrays
1578 as specified in ISO C99.
1580 * The ARM simulator now supports instruction level tracing
1581 with or without disassembly.
1585 GDB now has support for scripting using Guile. Whether this is
1586 available is determined at configure time.
1587 Guile version 2.0 or greater is required.
1588 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1590 * New commands (for set/show, see "New options" below)
1594 Invoke CODE by passing it to the Guile interpreter.
1598 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1600 info auto-load guile-scripts [regexp]
1601 Print the list of automatically loaded Guile scripts.
1603 * The source command is now capable of sourcing Guile scripts.
1604 This feature is dependent on the debugger being built with Guile support.
1608 set print symbol-loading (off|brief|full)
1609 show print symbol-loading
1610 Control whether to print informational messages when loading symbol
1611 information for a file. The default is "full", but when debugging
1612 programs with large numbers of shared libraries the amount of output
1613 becomes less useful.
1615 set guile print-stack (none|message|full)
1616 show guile print-stack
1617 Show a stack trace when an error is encountered in a Guile script.
1619 set auto-load guile-scripts (on|off)
1620 show auto-load guile-scripts
1621 Control auto-loading of Guile script files.
1623 maint ada set ignore-descriptive-types (on|off)
1624 maint ada show ignore-descriptive-types
1625 Control whether the debugger should ignore descriptive types in Ada
1626 programs. The default is not to ignore the descriptive types. See
1627 the user manual for more details on descriptive types and the intended
1628 usage of this option.
1630 set auto-connect-native-target
1632 Control whether GDB is allowed to automatically connect to the
1633 native target for the run, attach, etc. commands when not connected
1634 to any target yet. See also "target native" below.
1636 set record btrace replay-memory-access (read-only|read-write)
1637 show record btrace replay-memory-access
1638 Control what memory accesses are allowed during replay.
1640 maint set target-async (on|off)
1641 maint show target-async
1642 This controls whether GDB targets operate in synchronous or
1643 asynchronous mode. Normally the default is asynchronous, if it is
1644 available; but this can be changed to more easily debug problems
1645 occurring only in synchronous mode.
1647 set mi-async (on|off)
1649 Control whether MI asynchronous mode is preferred. This supersedes
1650 "set target-async" of previous GDB versions.
1652 * "set target-async" is deprecated as a CLI option and is now an alias
1653 for "set mi-async" (only puts MI into async mode).
1655 * Background execution commands (e.g., "c&", "s&", etc.) are now
1656 possible ``out of the box'' if the target supports them. Previously
1657 the user would need to explicitly enable the possibility with the
1658 "set target-async on" command.
1660 * New features in the GDB remote stub, GDBserver
1662 ** New option --debug-format=option1[,option2,...] allows one to add
1663 additional text to each output. At present only timestamps
1664 are supported: --debug-format=timestamps.
1665 Timestamps can also be turned on with the
1666 "monitor set debug-format timestamps" command from GDB.
1668 * The 'record instruction-history' command now starts counting instructions
1669 at one. This also affects the instruction ranges reported by the
1670 'record function-call-history' command when given the /i modifier.
1672 * The command 'record function-call-history' supports a new modifier '/c' to
1673 indent the function names based on their call stack depth.
1674 The fields for the '/i' and '/l' modifier have been reordered.
1675 The source line range is now prefixed with 'at'.
1676 The instruction range is now prefixed with 'inst'.
1677 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1678 "record instruction-history" and "list" commands.
1680 * The ranges given as arguments to the 'record function-call-history' and
1681 'record instruction-history' commands are now inclusive.
1683 * The btrace record target now supports the 'record goto' command.
1684 For locations inside the execution trace, the back trace is computed
1685 based on the information stored in the execution trace.
1687 * The btrace record target supports limited reverse execution and replay.
1688 The target does not record data and therefore does not allow reading
1689 memory or registers.
1691 * The "catch syscall" command now works on s390*-linux* targets.
1693 * The "compare-sections" command is no longer specific to target
1694 remote. It now works with all targets.
1696 * All native targets are now consistently called "native".
1697 Consequently, the "target child", "target GNU", "target djgpp",
1698 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1699 commands have been replaced with "target native". The QNX/NTO port
1700 leaves the "procfs" target in place and adds a "native" target for
1701 consistency with other ports. The impact on users should be minimal
1702 as these commands previously either throwed an error, or were
1703 no-ops. The target's name is visible in the output of the following
1704 commands: "help target", "info target", "info files", "maint print
1707 * The "target native" command now connects to the native target. This
1708 can be used to launch native programs even when "set
1709 auto-connect-native-target" is set to off.
1711 * GDB now supports access to Intel MPX registers on GNU/Linux.
1713 * Support for Intel AVX-512 registers on GNU/Linux.
1714 Support displaying and modifying Intel AVX-512 registers
1715 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1717 * New remote packets
1719 qXfer:btrace:read's annex
1720 The qXfer:btrace:read packet supports a new annex 'delta' to read
1721 branch trace incrementally.
1725 ** Valid Python operations on gdb.Value objects representing
1726 structs/classes invoke the corresponding overloaded operators if
1728 ** New `Xmethods' feature in the Python API. Xmethods are
1729 additional methods or replacements for existing methods of a C++
1730 class. This feature is useful for those cases where a method
1731 defined in C++ source code could be inlined or optimized out by
1732 the compiler, making it unavailable to GDB.
1735 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1737 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1738 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1739 its alias "share", instead.
1741 * The commands "set remotebaud" and "show remotebaud" are no longer
1742 supported. Use "set serial baud" and "show serial baud" (respectively)
1747 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1748 target-async". The latter is left as a deprecated alias of the
1749 former for backward compatibility. If the target supports it,
1750 CLI background execution commands are now always possible by
1751 default, independently of whether the frontend stated a
1752 preference for asynchronous execution with "-gdb-set mi-async".
1753 Previously "-gdb-set target-async off" affected both MI execution
1754 commands and CLI execution commands.
1756 *** Changes in GDB 7.7
1758 * Improved support for process record-replay and reverse debugging on
1759 arm*-linux* targets. Support for thumb32 and syscall instruction
1760 recording has been added.
1762 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1764 * GDB now supports Fission DWP file format version 2.
1765 http://gcc.gnu.org/wiki/DebugFission
1767 * New convenience function "$_isvoid", to check whether an expression
1768 is void. A void expression is an expression where the type of the
1769 result is "void". For example, some convenience variables may be
1770 "void" when evaluated (e.g., "$_exitcode" before the execution of
1771 the program being debugged; or an undefined convenience variable).
1772 Another example, when calling a function whose return type is
1775 * The "maintenance print objfiles" command now takes an optional regexp.
1777 * The "catch syscall" command now works on arm*-linux* targets.
1779 * GDB now consistently shows "<not saved>" when printing values of
1780 registers the debug info indicates have not been saved in the frame
1781 and there's nowhere to retrieve them from
1782 (callee-saved/call-clobbered registers):
1787 (gdb) info registers rax
1790 Before, the former would print "<optimized out>", and the latter
1791 "*value not available*".
1793 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1798 ** Frame filters and frame decorators have been added.
1799 ** Temporary breakpoints are now supported.
1800 ** Line tables representation has been added.
1801 ** New attribute 'parent_type' for gdb.Field objects.
1802 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1803 ** New attribute 'name' for gdb.Type objects.
1807 Nios II ELF nios2*-*-elf
1808 Nios II GNU/Linux nios2*-*-linux
1809 Texas Instruments MSP430 msp430*-*-elf
1811 * Removed native configurations
1813 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1814 been removed. ELF variants of these configurations are kept supported.
1816 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1817 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1818 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1819 i[34567]86-*-openbsd3.[0-3]
1820 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1821 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1822 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1826 Like "catch throw", but catches a re-thrown exception.
1827 maint check-psymtabs
1828 Renamed from old "maint check-symtabs".
1830 Perform consistency checks on symtabs.
1831 maint expand-symtabs
1832 Expand symtabs matching an optional regexp.
1835 Display the details of GDB configure-time options.
1837 maint set|show per-command
1838 maint set|show per-command space
1839 maint set|show per-command time
1840 maint set|show per-command symtab
1841 Enable display of per-command gdb resource usage.
1843 remove-symbol-file FILENAME
1844 remove-symbol-file -a ADDRESS
1845 Remove a symbol file added via add-symbol-file. The file to remove
1846 can be identified by its filename or by an address that lies within
1847 the boundaries of this symbol file in memory.
1850 info exceptions REGEXP
1851 Display the list of Ada exceptions defined in the program being
1852 debugged. If provided, only the exceptions whose names match REGEXP
1857 set debug symfile off|on
1859 Control display of debugging info regarding reading symbol files and
1860 symbol tables within those files
1862 set print raw frame-arguments
1863 show print raw frame-arguments
1864 Set/show whether to print frame arguments in raw mode,
1865 disregarding any defined pretty-printers.
1867 set remote trace-status-packet
1868 show remote trace-status-packet
1869 Set/show the use of remote protocol qTStatus packet.
1873 Control display of debugging messages related to Nios II targets.
1877 Control whether target-assisted range stepping is enabled.
1879 set startup-with-shell
1880 show startup-with-shell
1881 Specifies whether Unix child processes are started via a shell or
1886 Use the target memory cache for accesses to the code segment. This
1887 improves performance of remote debugging (particularly disassembly).
1889 * You can now use a literal value 'unlimited' for options that
1890 interpret 0 or -1 as meaning "unlimited". E.g., "set
1891 trace-buffer-size unlimited" is now an alias for "set
1892 trace-buffer-size -1" and "set height unlimited" is now an alias for
1895 * The "set debug symtab-create" debugging option of GDB has been changed to
1896 accept a verbosity level. 0 means "off", 1 provides basic debugging
1897 output, and values of 2 or greater provides more verbose output.
1899 * New command-line options
1901 Display the details of GDB configure-time options.
1903 * The command 'tsave' can now support new option '-ctf' to save trace
1904 buffer in Common Trace Format.
1906 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1909 * GDB now implements the the C++ 'typeid' operator.
1911 * The new convenience variable $_exception holds the exception being
1912 thrown or caught at an exception-related catchpoint.
1914 * The exception-related catchpoints, like "catch throw", now accept a
1915 regular expression which can be used to filter exceptions by type.
1917 * The new convenience variable $_exitsignal is automatically set to
1918 the terminating signal number when the program being debugged dies
1919 due to an uncaught signal.
1923 ** All MI commands now accept an optional "--language" option.
1924 Support for this feature can be verified by using the "-list-features"
1925 command, which should contain "language-option".
1927 ** The new command -info-gdb-mi-command allows the user to determine
1928 whether a GDB/MI command is supported or not.
1930 ** The "^error" result record returned when trying to execute an undefined
1931 GDB/MI command now provides a variable named "code" whose content is the
1932 "undefined-command" error code. Support for this feature can be verified
1933 by using the "-list-features" command, which should contain
1934 "undefined-command-error-code".
1936 ** The -trace-save MI command can optionally save trace buffer in Common
1939 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1941 ** The command -data-list-register-values now accepts an optional
1942 "--skip-unavailable" option. When used, only the available registers
1945 ** The new command -trace-frame-collected dumps collected variables,
1946 computed expressions, tvars, memory and registers in a traceframe.
1948 ** The commands -stack-list-locals, -stack-list-arguments and
1949 -stack-list-variables now accept an option "--skip-unavailable".
1950 When used, only the available locals or arguments are displayed.
1952 ** The -exec-run command now accepts an optional "--start" option.
1953 When used, the command follows the same semantics as the "start"
1954 command, stopping the program's execution at the start of its
1955 main subprogram. Support for this feature can be verified using
1956 the "-list-features" command, which should contain
1957 "exec-run-start-option".
1959 ** The new commands -catch-assert and -catch-exceptions insert
1960 catchpoints stopping the program when Ada exceptions are raised.
1962 ** The new command -info-ada-exceptions provides the equivalent of
1963 the new "info exceptions" command.
1965 * New system-wide configuration scripts
1966 A GDB installation now provides scripts suitable for use as system-wide
1967 configuration scripts for the following systems:
1971 * GDB now supports target-assigned range stepping with remote targets.
1972 This improves the performance of stepping source lines by reducing
1973 the number of control packets from/to GDB. See "New remote packets"
1976 * GDB now understands the element 'tvar' in the XML traceframe info.
1977 It has the id of the collected trace state variables.
1979 * On S/390 targets that provide the transactional-execution feature,
1980 the program interruption transaction diagnostic block (TDB) is now
1981 represented as a number of additional "registers" in GDB.
1983 * New remote packets
1987 The vCont packet supports a new 'r' action, that tells the remote
1988 stub to step through an address range itself, without GDB
1989 involvemement at each single-step.
1991 qXfer:libraries-svr4:read's annex
1992 The previously unused annex of the qXfer:libraries-svr4:read packet
1993 is now used to support passing an argument list. The remote stub
1994 reports support for this argument list to GDB's qSupported query.
1995 The defined arguments are "start" and "prev", used to reduce work
1996 necessary for library list updating, resulting in significant
1999 * New features in the GDB remote stub, GDBserver
2001 ** GDBserver now supports target-assisted range stepping. Currently
2002 enabled on x86/x86_64 GNU/Linux targets.
2004 ** GDBserver now adds element 'tvar' in the XML in the reply to
2005 'qXfer:traceframe-info:read'. It has the id of the collected
2006 trace state variables.
2008 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2011 * New 'z' formatter for printing and examining memory, this displays the
2012 value as hexadecimal zero padded on the left to the size of the type.
2014 * GDB can now use Windows x64 unwinding data.
2016 * The "set remotebaud" command has been replaced by "set serial baud".
2017 Similarly, "show remotebaud" has been replaced by "show serial baud".
2018 The "set remotebaud" and "show remotebaud" commands are still available
2019 to provide backward compatibility with older versions of GDB.
2021 *** Changes in GDB 7.6
2023 * Target record has been renamed to record-full.
2024 Record/replay is now enabled with the "record full" command.
2025 This also affects settings that are associated with full record/replay
2026 that have been moved from "set/show record" to "set/show record full":
2028 set|show record full insn-number-max
2029 set|show record full stop-at-limit
2030 set|show record full memory-query
2032 * A new record target "record-btrace" has been added. The new target
2033 uses hardware support to record the control-flow of a process. It
2034 does not support replaying the execution, but it implements the
2035 below new commands for investigating the recorded execution log.
2036 This new recording method can be enabled using:
2040 The "record-btrace" target is only available on Intel Atom processors
2041 and requires a Linux kernel 2.6.32 or later.
2043 * Two new commands have been added for record/replay to give information
2044 about the recorded execution without having to replay the execution.
2045 The commands are only supported by "record btrace".
2047 record instruction-history prints the execution history at
2048 instruction granularity
2050 record function-call-history prints the execution history at
2051 function granularity
2053 * New native configurations
2055 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2056 FreeBSD/powerpc powerpc*-*-freebsd
2057 x86_64/Cygwin x86_64-*-cygwin*
2058 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2062 ARM AArch64 aarch64*-*-elf
2063 ARM AArch64 GNU/Linux aarch64*-*-linux
2064 Lynx 178 PowerPC powerpc-*-lynx*178
2065 x86_64/Cygwin x86_64-*-cygwin*
2066 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2068 * If the configured location of system.gdbinit file (as given by the
2069 --with-system-gdbinit option at configure time) is in the
2070 data-directory (as specified by --with-gdb-datadir at configure
2071 time) or in one of its subdirectories, then GDB will look for the
2072 system-wide init file in the directory specified by the
2073 --data-directory command-line option.
2075 * New command line options:
2077 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2078 other initialization files, unlike -nx which disables all of them.
2080 * Removed command line options
2082 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2085 * The 'ptype' and 'whatis' commands now accept an argument to control
2088 * 'info proc' now works on some core files.
2092 ** Vectors can be created with gdb.Type.vector.
2094 ** Python's atexit.register now works in GDB.
2096 ** Types can be pretty-printed via a Python API.
2098 ** Python 3 is now supported (in addition to Python 2.4 or later)
2100 ** New class gdb.Architecture exposes GDB's internal representation
2101 of architecture in the Python API.
2103 ** New method Frame.architecture returns the gdb.Architecture object
2104 corresponding to the frame's architecture.
2106 * New Python-based convenience functions:
2108 ** $_memeq(buf1, buf2, length)
2109 ** $_streq(str1, str2)
2111 ** $_regex(str, regex)
2113 * The 'cd' command now defaults to using '~' (the home directory) if not
2116 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2117 default for GCC since November 2000.
2119 * The command 'forward-search' can now be abbreviated as 'fo'.
2121 * The command 'info tracepoints' can now display 'installed on target'
2122 or 'not installed on target' for each non-pending location of tracepoint.
2124 * New configure options
2126 --enable-libmcheck/--disable-libmcheck
2127 By default, development versions are built with -lmcheck on hosts
2128 that support it, in order to help track memory corruption issues.
2129 Release versions, on the other hand, are built without -lmcheck
2130 by default. The --enable-libmcheck/--disable-libmcheck configure
2131 options allow the user to override that default.
2132 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2133 This configure option allows the user to build GDB with
2134 libbabeltrace using which GDB can read Common Trace Format data.
2136 * New commands (for set/show, see "New options" below)
2139 Catch signals. This is similar to "handle", but allows commands and
2140 conditions to be attached.
2143 List the BFDs known to GDB.
2145 python-interactive [command]
2147 Start a Python interactive prompt, or evaluate the optional command
2148 and print the result of expressions.
2151 "py" is a new alias for "python".
2153 enable type-printer [name]...
2154 disable type-printer [name]...
2155 Enable or disable type printers.
2159 ** For the Renesas Super-H architecture, the "regs" command has been removed
2160 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2165 set print type methods (on|off)
2166 show print type methods
2167 Control whether method declarations are displayed by "ptype".
2168 The default is to show them.
2170 set print type typedefs (on|off)
2171 show print type typedefs
2172 Control whether typedef definitions are displayed by "ptype".
2173 The default is to show them.
2175 set filename-display basename|relative|absolute
2176 show filename-display
2177 Control the way in which filenames is displayed.
2178 The default is "relative", which preserves previous behavior.
2180 set trace-buffer-size
2181 show trace-buffer-size
2182 Request target to change the size of trace buffer.
2184 set remote trace-buffer-size-packet auto|on|off
2185 show remote trace-buffer-size-packet
2186 Control the use of the remote protocol `QTBuffer:size' packet.
2190 Control display of debugging messages related to ARM AArch64.
2193 set debug coff-pe-read
2194 show debug coff-pe-read
2195 Control display of debugging messages related to reading of COFF/PE
2200 Control display of debugging messages related to Mach-O symbols
2203 set debug notification
2204 show debug notification
2205 Control display of debugging info for async remote notification.
2209 ** Command parameter changes are now notified using new async record
2210 "=cmd-param-changed".
2211 ** Trace frame changes caused by command "tfind" are now notified using
2212 new async record "=traceframe-changed".
2213 ** The creation, deletion and modification of trace state variables
2214 are now notified using new async records "=tsv-created",
2215 "=tsv-deleted" and "=tsv-modified".
2216 ** The start and stop of process record are now notified using new
2217 async record "=record-started" and "=record-stopped".
2218 ** Memory changes are now notified using new async record
2220 ** The data-disassemble command response will include a "fullname" field
2221 containing the absolute file name when source has been requested.
2222 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2223 command, to allow pattern filling of memory areas.
2224 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2225 library load/unload events.
2226 ** The response to breakpoint commands and breakpoint async records
2227 includes an "installed" field containing a boolean state about each
2228 non-pending tracepoint location is whether installed on target or not.
2229 ** Output of the "-trace-status" command includes a "trace-file" field
2230 containing the name of the trace file being examined. This field is
2231 optional, and only present when examining a trace file.
2232 ** The "fullname" field is now always present along with the "file" field,
2233 even if the file cannot be found by GDB.
2235 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2236 You must have the LZMA library available when configuring GDB for this
2237 feature to be enabled. For more information, see:
2238 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2240 * New remote packets
2243 Set the size of trace buffer. The remote stub reports support for this
2244 packet to gdb's qSupported query.
2247 Enable Branch Trace Store (BTS)-based branch tracing for the current
2248 thread. The remote stub reports support for this packet to gdb's
2252 Disable branch tracing for the current thread. The remote stub reports
2253 support for this packet to gdb's qSupported query.
2256 Read the traced branches for the current thread. The remote stub
2257 reports support for this packet to gdb's qSupported query.
2259 *** Changes in GDB 7.5
2261 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2262 for more x32 ABI info.
2264 * GDB now supports access to MIPS DSP registers on Linux targets.
2266 * GDB now supports debugging microMIPS binaries.
2268 * The "info os" command on GNU/Linux can now display information on
2269 several new classes of objects managed by the operating system:
2270 "info os procgroups" lists process groups
2271 "info os files" lists file descriptors
2272 "info os sockets" lists internet-domain sockets
2273 "info os shm" lists shared-memory regions
2274 "info os semaphores" lists semaphores
2275 "info os msg" lists message queues
2276 "info os modules" lists loaded kernel modules
2278 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2279 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2280 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2281 options and inspect the probe arguments using the new $_probe_arg family
2282 of convenience variables. You can obtain more information about SystemTap
2283 in <http://sourceware.org/systemtap/>.
2285 * GDB now supports reversible debugging on ARM, it allows you to
2286 debug basic ARM and THUMB instructions, and provides
2287 record/replay support.
2289 * The option "symbol-reloading" has been deleted as it is no longer used.
2293 ** GDB commands implemented in Python can now be put in command class
2296 ** The "maint set python print-stack on|off" is now deleted.
2298 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2299 apply "flag enum"-style pretty-printing to any enum.
2301 ** gdb.lookup_symbol can now work when there is no current frame.
2303 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2304 the source at which the symbol was defined.
2306 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2307 method 'value'. The former indicates whether the symbol needs a
2308 frame in order to compute its value, and the latter computes the
2311 ** A new method 'referenced_value' on gdb.Value objects which can
2312 dereference pointer as well as C++ reference values.
2314 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2315 which return the global and static blocks (as gdb.Block objects),
2316 of the underlying symbol table, respectively.
2318 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2319 object associated with a PC value.
2321 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2322 of the address range occupied by code for the current source line.
2324 * Go language support.
2325 GDB now supports debugging programs written in the Go programming
2328 * GDBserver now supports stdio connections.
2329 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2331 * The binary "gdbtui" can no longer be built or installed.
2332 Use "gdb -tui" instead.
2334 * GDB will now print "flag" enums specially. A flag enum is one where
2335 all the enumerator values have no bits in common when pairwise
2336 "and"ed. When printing a value whose type is a flag enum, GDB will
2337 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2338 (gdb) print (enum E) 3
2341 * The filename part of a linespec will now match trailing components
2342 of a source file name. For example, "break gcc/expr.c:1000" will
2343 now set a breakpoint in build/gcc/expr.c, but not
2344 build/libcpp/expr.c.
2346 * The "info proc" and "generate-core-file" commands will now also
2347 work on remote targets connected to GDBserver on Linux.
2349 * The command "info catch" has been removed. It has been disabled
2350 since December 2007.
2352 * The "catch exception" and "catch assert" commands now accept
2353 a condition at the end of the command, much like the "break"
2354 command does. For instance:
2356 (gdb) catch exception Constraint_Error if Barrier = True
2358 Previously, it was possible to add a condition to such catchpoints,
2359 but it had to be done as a second step, after the catchpoint had been
2360 created, using the "condition" command.
2362 * The "info static-tracepoint-marker" command will now also work on
2363 native Linux targets with in-process agent.
2365 * GDB can now set breakpoints on inlined functions.
2367 * The .gdb_index section has been updated to include symbols for
2368 inlined functions. GDB will ignore older .gdb_index sections by
2369 default, which could cause symbol files to be loaded more slowly
2370 until their .gdb_index sections can be recreated. The new command
2371 "set use-deprecated-index-sections on" will cause GDB to use any older
2372 .gdb_index sections it finds. This will restore performance, but the
2373 ability to set breakpoints on inlined functions will be lost in symbol
2374 files with older .gdb_index sections.
2376 The .gdb_index section has also been updated to record more information
2377 about each symbol. This speeds up the "info variables", "info functions"
2378 and "info types" commands when used with programs having the .gdb_index
2379 section, as well as speeding up debugging with shared libraries using
2380 the .gdb_index section.
2382 * Ada support for GDB/MI Variable Objects has been added.
2384 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2389 ** New command -info-os is the MI equivalent of "info os".
2391 ** Output logs ("set logging" and related) now include MI output.
2395 ** "set use-deprecated-index-sections on|off"
2396 "show use-deprecated-index-sections on|off"
2397 Controls the use of deprecated .gdb_index sections.
2399 ** "catch load" and "catch unload" can be used to stop when a shared
2400 library is loaded or unloaded, respectively.
2402 ** "enable count" can be used to auto-disable a breakpoint after
2405 ** "info vtbl" can be used to show the virtual method tables for
2406 C++ and Java objects.
2408 ** "explore" and its sub commands "explore value" and "explore type"
2409 can be used to recursively explore values and types of
2410 expressions. These commands are available only if GDB is
2411 configured with '--with-python'.
2413 ** "info auto-load" shows status of all kinds of auto-loaded files,
2414 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2415 sequences of commands files, "info auto-load python-scripts"
2416 shows status of auto-loading Python script files,
2417 "info auto-load local-gdbinit" shows status of loading init file
2418 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2419 status of inferior specific thread debugging shared library loading.
2421 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2422 and "show auto-load-scripts" commands have been deprecated, use their
2423 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2424 and "show auto-load python-scripts" counterparts instead.
2426 ** "dprintf location,format,args..." creates a dynamic printf, which
2427 is basically a breakpoint that does a printf and immediately
2428 resumes your program's execution, so it is like a printf that you
2429 can insert dynamically at runtime instead of at compiletime.
2431 ** "set print symbol"
2433 Controls whether GDB attempts to display the symbol, if any,
2434 corresponding to addresses it prints. This defaults to "on", but
2435 you can set it to "off" to restore GDB's previous behavior.
2437 * Deprecated commands
2439 ** For the Renesas Super-H architecture, the "regs" command has been
2440 deprecated, and "info all-registers" should be used instead.
2444 Renesas RL78 rl78-*-elf
2445 HP OpenVMS ia64 ia64-hp-openvms*
2447 * GDBserver supports evaluation of breakpoint conditions. When
2448 support is advertised by GDBserver, GDB may be told to send the
2449 breakpoint conditions in bytecode form to GDBserver. GDBserver
2450 will only report the breakpoint trigger to GDB when its condition
2455 set mips compression
2456 show mips compression
2457 Select the compressed ISA encoding used in functions that have no symbol
2458 information available. The encoding can be set to either of:
2461 and is updated automatically from ELF file flags if available.
2463 set breakpoint condition-evaluation
2464 show breakpoint condition-evaluation
2465 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2466 GDBserver ("target"). Default option "auto" chooses the most efficient
2468 This option can improve debugger efficiency depending on the speed of the
2472 Disable auto-loading globally.
2475 Show auto-loading setting of all kinds of auto-loaded files.
2477 set auto-load gdb-scripts on|off
2478 show auto-load gdb-scripts
2479 Control auto-loading of GDB canned sequences of commands files.
2481 set auto-load python-scripts on|off
2482 show auto-load python-scripts
2483 Control auto-loading of Python script files.
2485 set auto-load local-gdbinit on|off
2486 show auto-load local-gdbinit
2487 Control loading of init file (.gdbinit) from current directory.
2489 set auto-load libthread-db on|off
2490 show auto-load libthread-db
2491 Control auto-loading of inferior specific thread debugging shared library.
2493 set auto-load scripts-directory <dir1>[:<dir2>...]
2494 show auto-load scripts-directory
2495 Set a list of directories from which to load auto-loaded scripts.
2496 Automatically loaded Python scripts and GDB scripts are located in one
2497 of the directories listed by this option.
2498 The delimiter (':' above) may differ according to the host platform.
2500 set auto-load safe-path <dir1>[:<dir2>...]
2501 show auto-load safe-path
2502 Set a list of directories from which it is safe to auto-load files.
2503 The delimiter (':' above) may differ according to the host platform.
2505 set debug auto-load on|off
2506 show debug auto-load
2507 Control display of debugging info for auto-loading the files above.
2509 set dprintf-style gdb|call|agent
2511 Control the way in which a dynamic printf is performed; "gdb"
2512 requests a GDB printf command, while "call" causes dprintf to call a
2513 function in the inferior. "agent" requests that the target agent
2514 (such as GDBserver) do the printing.
2516 set dprintf-function <expr>
2517 show dprintf-function
2518 set dprintf-channel <expr>
2519 show dprintf-channel
2520 Set the function and optional first argument to the call when using
2521 the "call" style of dynamic printf.
2523 set disconnected-dprintf on|off
2524 show disconnected-dprintf
2525 Control whether agent-style dynamic printfs continue to be in effect
2526 after GDB disconnects.
2528 * New configure options
2530 --with-auto-load-dir
2531 Configure default value for the 'set auto-load scripts-directory'
2532 setting above. It defaults to '$debugdir:$datadir/auto-load',
2533 $debugdir representing global debugging info directories (available
2534 via 'show debug-file-directory') and $datadir representing GDB's data
2535 directory (available via 'show data-directory').
2537 --with-auto-load-safe-path
2538 Configure default value for the 'set auto-load safe-path' setting
2539 above. It defaults to the --with-auto-load-dir setting.
2541 --without-auto-load-safe-path
2542 Set 'set auto-load safe-path' to '/', effectively disabling this
2545 * New remote packets
2547 z0/z1 conditional breakpoints extension
2549 The z0/z1 breakpoint insertion packets have been extended to carry
2550 a list of conditional expressions over to the remote stub depending on the
2551 condition evaluation mode. The use of this extension can be controlled
2552 via the "set remote conditional-breakpoints-packet" command.
2556 Specify the signals which the remote stub may pass to the debugged
2557 program without GDB involvement.
2559 * New command line options
2561 --init-command=FILE, -ix Like --command, -x but execute it
2562 before loading inferior.
2563 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2564 execute it before loading inferior.
2566 *** Changes in GDB 7.4
2568 * GDB now handles ambiguous linespecs more consistently; the existing
2569 FILE:LINE support has been expanded to other types of linespecs. A
2570 breakpoint will now be set on all matching locations in all
2571 inferiors, and locations will be added or removed according to
2574 * GDB now allows you to skip uninteresting functions and files when
2575 stepping with the "skip function" and "skip file" commands.
2577 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2578 and "show remote hardware-watchpoint-length-limit". These allows to
2579 set or show the maximum length limit (in bytes) of a remote
2580 target hardware watchpoint.
2582 This allows e.g. to use "unlimited" hardware watchpoints with the
2583 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2584 watchpoints are slower than real hardware watchpoints but are
2585 significantly faster than gdb software watchpoints.
2589 ** The register_pretty_printer function in module gdb.printing now takes
2590 an optional `replace' argument. If True, the new printer replaces any
2593 ** The "maint set python print-stack on|off" command has been
2594 deprecated and will be deleted in GDB 7.5.
2595 A new command: "set python print-stack none|full|message" has
2596 replaced it. Additionally, the default for "print-stack" is
2597 now "message", which just prints the error message without
2600 ** A prompt substitution hook (prompt_hook) is now available to the
2603 ** A new Python module, gdb.prompt has been added to the GDB Python
2604 modules library. This module provides functionality for
2605 escape sequences in prompts (used by set/show
2606 extended-prompt). These escape sequences are replaced by their
2607 corresponding value.
2609 ** Python commands and convenience-functions located in
2610 'data-directory'/python/gdb/command and
2611 'data-directory'/python/gdb/function are now automatically loaded
2614 ** Blocks now provide four new attributes. global_block and
2615 static_block will return the global and static blocks
2616 respectively. is_static and is_global are boolean attributes
2617 that indicate if the block is one of those two types.
2619 ** Symbols now provide the "type" attribute, the type of the symbol.
2621 ** The "gdb.breakpoint" function has been deprecated in favor of
2624 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2625 of a function. This class is based on the "finish" command
2626 available in the CLI.
2628 ** Type objects for struct and union types now allow access to
2629 the fields using standard Python dictionary (mapping) methods.
2630 For example, "some_type['myfield']" now works, as does
2631 "some_type.items()".
2633 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2636 ** A new function, "deep_items" has been added to the gdb.types
2637 module in the GDB Python modules library. This function returns
2638 an iterator over the fields of a struct or union type. Unlike
2639 the standard Python "iteritems" method, it will recursively traverse
2640 any anonymous fields.
2644 ** "*stopped" events can report several new "reason"s, such as
2647 ** Breakpoint changes are now notified using new async records, like
2648 "=breakpoint-modified".
2650 ** New command -ada-task-info.
2652 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2653 $sdir specifies the default system locations of shared libraries.
2654 $pdir specifies the directory where the libpthread used by the application
2657 GDB no longer looks in $sdir and $pdir after it has searched the directories
2658 mentioned in libthread-db-search-path. If you want to search those
2659 directories, they must be specified in libthread-db-search-path.
2660 The default value of libthread-db-search-path on GNU/Linux and Solaris
2661 systems is now "$sdir:$pdir".
2663 $pdir is not supported by gdbserver, it is currently ignored.
2664 $sdir is supported by gdbserver.
2666 * New configure option --with-iconv-bin.
2667 When using the internationalization support like the one in the GNU C
2668 library, GDB will invoke the "iconv" program to get a list of supported
2669 character sets. If this program lives in a non-standard location, one can
2670 use this option to specify where to find it.
2672 * When natively debugging programs on PowerPC BookE processors running
2673 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2674 watchpoints, which specify a mask in addition to an address to watch.
2675 The mask specifies that some bits of an address (the bits which are
2676 reset in the mask) should be ignored when matching the address accessed
2677 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2678 section in the user manual for more details.
2680 * The new option --once causes GDBserver to stop listening for connections once
2681 the first connection is made. The listening port used by GDBserver will
2682 become available after that.
2684 * New commands "info macros" and "alias" have been added.
2686 * New function parameters suffix @entry specifies value of function parameter
2687 at the time the function got called. Entry values are available only since
2693 "!" is now an alias of the "shell" command.
2694 Note that no space is needed between "!" and SHELL COMMAND.
2698 watch EXPRESSION mask MASK_VALUE
2699 The watch command now supports the mask argument which allows creation
2700 of masked watchpoints, if the current architecture supports this feature.
2702 info auto-load-scripts [REGEXP]
2703 This command was formerly named "maintenance print section-scripts".
2704 It is now generally useful and is no longer a maintenance-only command.
2706 info macro [-all] [--] MACRO
2707 The info macro command has new options `-all' and `--'. The first for
2708 printing all definitions of a macro. The second for explicitly specifying
2709 the end of arguments and the beginning of the macro name in case the macro
2710 name starts with a hyphen.
2712 collect[/s] EXPRESSIONS
2713 The tracepoint collect command now takes an optional modifier "/s"
2714 that directs it to dereference pointer-to-character types and
2715 collect the bytes of memory up to a zero byte. The behavior is
2716 similar to what you see when you use the regular print command on a
2717 string. An optional integer following the "/s" sets a bound on the
2718 number of bytes that will be collected.
2721 The trace start command now interprets any supplied arguments as a
2722 note to be recorded with the trace run, with an effect similar to
2723 setting the variable trace-notes.
2726 The trace stop command now interprets any arguments as a note to be
2727 mentioned along with the tstatus report that the trace was stopped
2728 with a command. The effect is similar to setting the variable
2731 * Tracepoints can now be enabled and disabled at any time after a trace
2732 experiment has been started using the standard "enable" and "disable"
2733 commands. It is now possible to start a trace experiment with no enabled
2734 tracepoints; GDB will display a warning, but will allow the experiment to
2735 begin, assuming that tracepoints will be enabled as needed while the trace
2738 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2739 locations with 4-byte instructions, when they were previously
2740 limited to locations with instructions of 5 bytes or longer.
2744 set debug dwarf2-read
2745 show debug dwarf2-read
2746 Turns on or off display of debugging messages related to reading
2747 DWARF debug info. The default is off.
2749 set debug symtab-create
2750 show debug symtab-create
2751 Turns on or off display of debugging messages related to symbol table
2752 creation. The default is off.
2755 show extended-prompt
2756 Set the GDB prompt, and allow escape sequences to be inserted to
2757 display miscellaneous information (see 'help set extended-prompt'
2758 for the list of sequences). This prompt (and any information
2759 accessed through the escape sequences) is updated every time the
2760 prompt is displayed.
2762 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2763 show print entry-values
2764 Set printing of frame argument values at function entry. In some cases
2765 GDB can determine the value of function argument which was passed by the
2766 function caller, even if the value was modified inside the called function.
2768 set debug entry-values
2769 show debug entry-values
2770 Control display of debugging info for determining frame argument values at
2771 function entry and virtual tail call frames.
2773 set basenames-may-differ
2774 show basenames-may-differ
2775 Set whether a source file may have multiple base names.
2776 (A "base name" is the name of a file with the directory part removed.
2777 Example: The base name of "/home/user/hello.c" is "hello.c".)
2778 If set, GDB will canonicalize file names (e.g., expand symlinks)
2779 before comparing them. Canonicalization is an expensive operation,
2780 but it allows the same file be known by more than one base name.
2781 If not set (the default), all source files are assumed to have just
2782 one base name, and gdb will do file name comparisons more efficiently.
2788 Set a user name and notes for the current and any future trace runs.
2789 This is useful for long-running and/or disconnected traces, to
2790 inform others (or yourself) as to who is running the trace, supply
2791 contact information, or otherwise explain what is going on.
2793 set trace-stop-notes
2794 show trace-stop-notes
2795 Set a note attached to the trace run, that is displayed when the
2796 trace has been stopped by a tstop command. This is useful for
2797 instance as an explanation, if you are stopping a trace run that was
2798 started by someone else.
2800 * New remote packets
2804 Dynamically enable a tracepoint in a started trace experiment.
2808 Dynamically disable a tracepoint in a started trace experiment.
2812 Set the user and notes of the trace run.
2816 Query the current status of a tracepoint.
2820 Query the minimum length of instruction at which a fast tracepoint may
2823 * Dcache size (number of lines) and line-size are now runtime-configurable
2824 via "set dcache line" and "set dcache line-size" commands.
2828 Texas Instruments TMS320C6x tic6x-*-*
2832 Renesas RL78 rl78-*-elf
2834 *** Changes in GDB 7.3.1
2836 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2838 *** Changes in GDB 7.3
2840 * GDB has a new command: "thread find [REGEXP]".
2841 It finds the thread id whose name, target id, or thread extra info
2842 matches the given regular expression.
2844 * The "catch syscall" command now works on mips*-linux* targets.
2846 * The -data-disassemble MI command now supports modes 2 and 3 for
2847 dumping the instruction opcodes.
2849 * New command line options
2851 -data-directory DIR Specify DIR as the "data-directory".
2852 This is mostly for testing purposes.
2854 * The "maint set python auto-load on|off" command has been renamed to
2855 "set auto-load-scripts on|off".
2857 * GDB has a new command: "set directories".
2858 It is like the "dir" command except that it replaces the
2859 source path list instead of augmenting it.
2861 * GDB now understands thread names.
2863 On GNU/Linux, "info threads" will display the thread name as set by
2864 prctl or pthread_setname_np.
2866 There is also a new command, "thread name", which can be used to
2867 assign a name internally for GDB to display.
2870 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2871 has been integrated into GDB.
2875 ** The function gdb.Write now accepts an optional keyword 'stream'.
2876 This keyword, when provided, will direct the output to either
2877 stdout, stderr, or GDB's logging output.
2879 ** Parameters can now be be sub-classed in Python, and in particular
2880 you may implement the get_set_doc and get_show_doc functions.
2881 This improves how Parameter set/show documentation is processed
2882 and allows for more dynamic content.
2884 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2885 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2886 have an is_valid method.
2888 ** Breakpoints can now be sub-classed in Python, and in particular
2889 you may implement a 'stop' function that is executed each time
2890 the inferior reaches that breakpoint.
2892 ** New function gdb.lookup_global_symbol looks up a global symbol.
2894 ** GDB values in Python are now callable if the value represents a
2895 function. For example, if 'some_value' represents a function that
2896 takes two integer parameters and returns a value, you can call
2897 that function like so:
2899 result = some_value (10,20)
2901 ** Module gdb.types has been added.
2902 It contains a collection of utilities for working with gdb.Types objects:
2903 get_basic_type, has_field, make_enum_dict.
2905 ** Module gdb.printing has been added.
2906 It contains utilities for writing and registering pretty-printers.
2907 New classes: PrettyPrinter, SubPrettyPrinter,
2908 RegexpCollectionPrettyPrinter.
2909 New function: register_pretty_printer.
2911 ** New commands "info pretty-printers", "enable pretty-printer" and
2912 "disable pretty-printer" have been added.
2914 ** gdb.parameter("directories") is now available.
2916 ** New function gdb.newest_frame returns the newest frame in the
2919 ** The gdb.InferiorThread class has a new "name" attribute. This
2920 holds the thread's name.
2922 ** Python Support for Inferior events.
2923 Python scripts can add observers to be notified of events
2924 occurring in the process being debugged.
2925 The following events are currently supported:
2926 - gdb.events.cont Continue event.
2927 - gdb.events.exited Inferior exited event.
2928 - gdb.events.stop Signal received, and Breakpoint hit events.
2932 ** GDB now puts template parameters in scope when debugging in an
2933 instantiation. For example, if you have:
2935 template<int X> int func (void) { return X; }
2937 then if you step into func<5>, "print X" will show "5". This
2938 feature requires proper debuginfo support from the compiler; it
2939 was added to GCC 4.5.
2941 ** The motion commands "next", "finish", "until", and "advance" now
2942 work better when exceptions are thrown. In particular, GDB will
2943 no longer lose control of the inferior; instead, the GDB will
2944 stop the inferior at the point at which the exception is caught.
2945 This functionality requires a change in the exception handling
2946 code that was introduced in GCC 4.5.
2948 * GDB now follows GCC's rules on accessing volatile objects when
2949 reading or writing target state during expression evaluation.
2950 One notable difference to prior behavior is that "print x = 0"
2951 no longer generates a read of x; the value of the assignment is
2952 now always taken directly from the value being assigned.
2954 * GDB now has some support for using labels in the program's source in
2955 linespecs. For instance, you can use "advance label" to continue
2956 execution to a label.
2958 * GDB now has support for reading and writing a new .gdb_index
2959 section. This section holds a fast index of DWARF debugging
2960 information and can be used to greatly speed up GDB startup and
2961 operation. See the documentation for `save gdb-index' for details.
2963 * The "watch" command now accepts an optional "-location" argument.
2964 When used, this causes GDB to watch the memory referred to by the
2965 expression. Such a watchpoint is never deleted due to it going out
2968 * GDB now supports thread debugging of core dumps on GNU/Linux.
2970 GDB now activates thread debugging using the libthread_db library
2971 when debugging GNU/Linux core dumps, similarly to when debugging
2972 live processes. As a result, when debugging a core dump file, GDB
2973 is now able to display pthread_t ids of threads. For example, "info
2974 threads" shows the same output as when debugging the process when it
2975 was live. In earlier releases, you'd see something like this:
2978 * 1 LWP 6780 main () at main.c:10
2980 While now you see this:
2983 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2985 It is also now possible to inspect TLS variables when debugging core
2988 When debugging a core dump generated on a machine other than the one
2989 used to run GDB, you may need to point GDB at the correct
2990 libthread_db library with the "set libthread-db-search-path"
2991 command. See the user manual for more details on this command.
2993 * When natively debugging programs on PowerPC BookE processors running
2994 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2995 which stop execution of the inferior whenever it executes an instruction
2996 at any address within the specified range. See the "PowerPC Embedded"
2997 section in the user manual for more details.
2999 * New features in the GDB remote stub, GDBserver
3001 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3002 and i686 LynxOS (version 5.x).
3004 ** GDBserver is now supported on Blackfin Linux.
3006 * New native configurations
3008 ia64 HP-UX ia64-*-hpux*
3012 Analog Devices, Inc. Blackfin Processor bfin-*
3014 * Ada task switching is now supported on sparc-elf targets when
3015 debugging a program using the Ravenscar Profile. For more information,
3016 see the "Tasking Support when using the Ravenscar Profile" section
3017 in the GDB user manual.
3019 * Guile support was removed.
3021 * New features in the GNU simulator
3023 ** The --map-info flag lists all known core mappings.
3025 ** CFI flashes may be simulated via the "cfi" device.
3027 *** Changes in GDB 7.2
3029 * Shared library support for remote targets by default
3031 When GDB is configured for a generic, non-OS specific target, like
3032 for example, --target=arm-eabi or one of the many *-*-elf targets,
3033 GDB now queries remote stubs for loaded shared libraries using the
3034 `qXfer:libraries:read' packet. Previously, shared library support
3035 was always disabled for such configurations.
3039 ** Argument Dependent Lookup (ADL)
3041 In C++ ADL lookup directs function search to the namespaces of its
3042 arguments even if the namespace has not been imported.
3052 Here the compiler will search for `foo' in the namespace of 'b'
3053 and find A::foo. GDB now supports this. This construct is commonly
3054 used in the Standard Template Library for operators.
3056 ** Improved User Defined Operator Support
3058 In addition to member operators, GDB now supports lookup of operators
3059 defined in a namespace and imported with a `using' directive, operators
3060 defined in the global scope, operators imported implicitly from an
3061 anonymous namespace, and the ADL operators mentioned in the previous
3063 GDB now also supports proper overload resolution for all the previously
3064 mentioned flavors of operators.
3066 ** static const class members
3068 Printing of static const class members that are initialized in the
3069 class definition has been fixed.
3071 * Windows Thread Information Block access.
3073 On Windows targets, GDB now supports displaying the Windows Thread
3074 Information Block (TIB) structure. This structure is visible either
3075 by using the new command `info w32 thread-information-block' or, by
3076 dereferencing the new convenience variable named `$_tlb', a
3077 thread-specific pointer to the TIB. This feature is also supported
3078 when remote debugging using GDBserver.
3080 * Static tracepoints
3082 Static tracepoints are calls in the user program into a tracing
3083 library. One such library is a port of the LTTng kernel tracer to
3084 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3085 When debugging with GDBserver, GDB now supports combining the GDB
3086 tracepoint machinery with such libraries. For example: the user can
3087 use GDB to probe a static tracepoint marker (a call from the user
3088 program into the tracing library) with the new "strace" command (see
3089 "New commands" below). This creates a "static tracepoint" in the
3090 breakpoint list, that can be manipulated with the same feature set
3091 as fast and regular tracepoints. E.g., collect registers, local and
3092 global variables, collect trace state variables, and define
3093 tracepoint conditions. In addition, the user can collect extra
3094 static tracepoint marker specific data, by collecting the new
3095 $_sdata internal variable. When analyzing the trace buffer, you can
3096 inspect $_sdata like any other variable available to GDB. For more
3097 information, see the "Tracepoints" chapter in GDB user manual. New
3098 remote packets have been defined to support static tracepoints, see
3099 the "New remote packets" section below.
3101 * Better reconstruction of tracepoints after disconnected tracing
3103 GDB will attempt to download the original source form of tracepoint
3104 definitions when starting a trace run, and then will upload these
3105 upon reconnection to the target, resulting in a more accurate
3106 reconstruction of the tracepoints that are in use on the target.
3110 You can now exercise direct control over the ways that GDB can
3111 affect your program. For instance, you can disallow the setting of
3112 breakpoints, so that the program can run continuously (assuming
3113 non-stop mode). In addition, the "observer" variable is available
3114 to switch all of the different controls; in observer mode, GDB
3115 cannot affect the target's behavior at all, which is useful for
3116 tasks like diagnosing live systems in the field.
3118 * The new convenience variable $_thread holds the number of the
3121 * New remote packets
3125 Return the address of the Windows Thread Information Block of a given thread.
3129 In response to several of the tracepoint packets, the target may now
3130 also respond with a number of intermediate `qRelocInsn' request
3131 packets before the final result packet, to have GDB handle
3132 relocating an instruction to execute at a different address. This
3133 is particularly useful for stubs that support fast tracepoints. GDB
3134 reports support for this feature in the qSupported packet.
3138 List static tracepoint markers in the target program.
3142 List static tracepoint markers at a given address in the target
3145 qXfer:statictrace:read
3147 Read the static trace data collected (by a `collect $_sdata'
3148 tracepoint action). The remote stub reports support for this packet
3149 to gdb's qSupported query.
3153 Send the current settings of GDB's permission flags.
3157 Send part of the source (textual) form of a tracepoint definition,
3158 which includes location, conditional, and action list.
3160 * The source command now accepts a -s option to force searching for the
3161 script in the source search path even if the script name specifies
3164 * New features in the GDB remote stub, GDBserver
3166 - GDBserver now support tracepoints (including fast tracepoints, and
3167 static tracepoints). The feature is currently supported by the
3168 i386-linux and amd64-linux builds. See the "Tracepoints support
3169 in gdbserver" section in the manual for more information.
3171 GDBserver JIT compiles the tracepoint's conditional agent
3172 expression bytecode into native code whenever possible for low
3173 overhead dynamic tracepoints conditionals. For such tracepoints,
3174 an expression that examines program state is evaluated when the
3175 tracepoint is reached, in order to determine whether to capture
3176 trace data. If the condition is simple and false, processing the
3177 tracepoint finishes very quickly and no data is gathered.
3179 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3180 for static tracepoints support.
3182 - GDBserver now supports x86_64 Windows 64-bit debugging.
3184 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3185 it understands register description.
3187 * The --batch flag now disables pagination and queries.
3189 * X86 general purpose registers
3191 GDB now supports reading/writing byte, word and double-word x86
3192 general purpose registers directly. This means you can use, say,
3193 $ah or $ax to refer, respectively, to the byte register AH and
3194 16-bit word register AX that are actually portions of the 32-bit
3195 register EAX or 64-bit register RAX.
3197 * The `commands' command now accepts a range of breakpoints to modify.
3198 A plain `commands' following a command that creates multiple
3199 breakpoints affects all the breakpoints set by that command. This
3200 applies to breakpoints set by `rbreak', and also applies when a
3201 single `break' command creates multiple breakpoints (e.g.,
3202 breakpoints on overloaded c++ functions).
3204 * The `rbreak' command now accepts a filename specification as part of
3205 its argument, limiting the functions selected by the regex to those
3206 in the specified file.
3208 * Support for remote debugging Windows and SymbianOS shared libraries
3209 from Unix hosts has been improved. Non Windows GDB builds now can
3210 understand target reported file names that follow MS-DOS based file
3211 system semantics, such as file names that include drive letters and
3212 use the backslash character as directory separator. This makes it
3213 possible to transparently use the "set sysroot" and "set
3214 solib-search-path" on Unix hosts to point as host copies of the
3215 target's shared libraries. See the new command "set
3216 target-file-system-kind" described below, and the "Commands to
3217 specify files" section in the user manual for more information.
3221 eval template, expressions...
3222 Convert the values of one or more expressions under the control
3223 of the string template to a command line, and call it.
3225 set target-file-system-kind unix|dos-based|auto
3226 show target-file-system-kind
3227 Set or show the assumed file system kind for target reported file
3230 save breakpoints <filename>
3231 Save all current breakpoint definitions to a file suitable for use
3232 in a later debugging session. To read the saved breakpoint
3233 definitions, use the `source' command.
3235 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3238 info static-tracepoint-markers
3239 Display information about static tracepoint markers in the target.
3241 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3242 Define a static tracepoint by probing a marker at the given
3243 function, line, address, or marker ID.
3247 Enable and disable observer mode.
3249 set may-write-registers on|off
3250 set may-write-memory on|off
3251 set may-insert-breakpoints on|off
3252 set may-insert-tracepoints on|off
3253 set may-insert-fast-tracepoints on|off
3254 set may-interrupt on|off
3255 Set individual permissions for GDB effects on the target. Note that
3256 some of these settings can have undesirable or surprising
3257 consequences, particularly when changed in the middle of a session.
3258 For instance, disabling the writing of memory can prevent
3259 breakpoints from being inserted, cause single-stepping to fail, or
3260 even crash your program, if you disable after breakpoints have been
3261 inserted. However, GDB should not crash.
3263 set record memory-query on|off
3264 show record memory-query
3265 Control whether to stop the inferior if memory changes caused
3266 by an instruction cannot be recorded.
3271 The disassemble command now supports "start,+length" form of two arguments.
3275 ** GDB now provides a new directory location, called the python directory,
3276 where Python scripts written for GDB can be installed. The location
3277 of that directory is <data-directory>/python, where <data-directory>
3278 is the GDB data directory. For more details, see section `Scripting
3279 GDB using Python' in the manual.
3281 ** The GDB Python API now has access to breakpoints, symbols, symbol
3282 tables, program spaces, inferiors, threads and frame's code blocks.
3283 Additionally, GDB Parameters can now be created from the API, and
3284 manipulated via set/show in the CLI.
3286 ** New functions gdb.target_charset, gdb.target_wide_charset,
3287 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3289 ** New exception gdb.GdbError.
3291 ** Pretty-printers are now also looked up in the current program space.
3293 ** Pretty-printers can now be individually enabled and disabled.
3295 ** GDB now looks for names of Python scripts to auto-load in a
3296 special section named `.debug_gdb_scripts', in addition to looking
3297 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3299 * Tracepoint actions were unified with breakpoint commands. In particular,
3300 there are no longer differences in "info break" output for breakpoints and
3301 tracepoints and the "commands" command can be used for both tracepoints and
3302 regular breakpoints.
3306 ARM Symbian arm*-*-symbianelf*
3308 * D language support.
3309 GDB now supports debugging programs written in the D programming
3312 * GDB now supports the extended ptrace interface for PowerPC which is
3313 available since Linux kernel version 2.6.34. This automatically enables
3314 any hardware breakpoints and additional hardware watchpoints available in
3315 the processor. The old ptrace interface exposes just one hardware
3316 watchpoint and no hardware breakpoints.
3318 * GDB is now able to use the Data Value Compare (DVC) register available on
3319 embedded PowerPC processors to implement in hardware simple watchpoint
3320 conditions of the form:
3322 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3324 This works in native GDB running on Linux kernels with the extended ptrace
3325 interface mentioned above.
3327 *** Changes in GDB 7.1
3331 ** Namespace Support
3333 GDB now supports importing of namespaces in C++. This enables the
3334 user to inspect variables from imported namespaces. Support for
3335 namepace aliasing has also been added. So, if a namespace is
3336 aliased in the current scope (e.g. namepace C=A; ) the user can
3337 print variables using the alias (e.g. (gdb) print C::x).
3341 All known bugs relating to the printing of virtual base class were
3342 fixed. It is now possible to call overloaded static methods using a
3347 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3348 and reinterpret_cast<> are now handled by the C++ expression parser.
3352 Xilinx MicroBlaze microblaze-*-*
3357 Xilinx MicroBlaze microblaze
3360 * Multi-program debugging.
3362 GDB now has support for multi-program (a.k.a. multi-executable or
3363 multi-exec) debugging. This allows for debugging multiple inferiors
3364 simultaneously each running a different program under the same GDB
3365 session. See "Debugging Multiple Inferiors and Programs" in the
3366 manual for more information. This implied some user visible changes
3367 in the multi-inferior support. For example, "info inferiors" now
3368 lists inferiors that are not running yet or that have exited
3369 already. See also "New commands" and "New options" below.
3371 * New tracing features
3373 GDB's tracepoint facility now includes several new features:
3375 ** Trace state variables
3377 GDB tracepoints now include support for trace state variables, which
3378 are variables managed by the target agent during a tracing
3379 experiment. They are useful for tracepoints that trigger each
3380 other, so for instance one tracepoint can count hits in a variable,
3381 and then a second tracepoint has a condition that is true when the
3382 count reaches a particular value. Trace state variables share the
3383 $-syntax of GDB convenience variables, and can appear in both
3384 tracepoint actions and condition expressions. Use the "tvariable"
3385 command to create, and "info tvariables" to view; see "Trace State
3386 Variables" in the manual for more detail.
3390 GDB now includes an option for defining fast tracepoints, which
3391 targets may implement more efficiently, such as by installing a jump
3392 into the target agent rather than a trap instruction. The resulting
3393 speedup can be by two orders of magnitude or more, although the
3394 tradeoff is that some program locations on some target architectures
3395 might not allow fast tracepoint installation, for instance if the
3396 instruction to be replaced is shorter than the jump. To request a
3397 fast tracepoint, use the "ftrace" command, with syntax identical to
3398 the regular trace command.
3400 ** Disconnected tracing
3402 It is now possible to detach GDB from the target while it is running
3403 a trace experiment, then reconnect later to see how the experiment
3404 is going. In addition, a new variable disconnected-tracing lets you
3405 tell the target agent whether to continue running a trace if the
3406 connection is lost unexpectedly.
3410 GDB now has the ability to save the trace buffer into a file, and
3411 then use that file as a target, similarly to you can do with
3412 corefiles. You can select trace frames, print data that was
3413 collected in them, and use tstatus to display the state of the
3414 tracing run at the moment that it was saved. To create a trace
3415 file, use "tsave <filename>", and to use it, do "target tfile
3418 ** Circular trace buffer
3420 You can ask the target agent to handle the trace buffer as a
3421 circular buffer, discarding the oldest trace frames to make room for
3422 newer ones, by setting circular-trace-buffer to on. This feature may
3423 not be available for all target agents.
3428 The disassemble command, when invoked with two arguments, now requires
3429 the arguments to be comma-separated.
3432 The info variables command now displays variable definitions. Files
3433 which only declare a variable are not shown.
3436 The source command is now capable of sourcing Python scripts.
3437 This feature is dependent on the debugger being build with Python
3440 Related to this enhancement is also the introduction of a new command
3441 "set script-extension" (see below).
3443 * New commands (for set/show, see "New options" below)
3445 record save [<FILENAME>]
3446 Save a file (in core file format) containing the process record
3447 execution log for replay debugging at a later time.
3449 record restore <FILENAME>
3450 Restore the process record execution log that was saved at an
3451 earlier time, for replay debugging.
3453 add-inferior [-copies <N>] [-exec <FILENAME>]
3456 clone-inferior [-copies <N>] [ID]
3457 Make a new inferior ready to execute the same program another
3458 inferior has loaded.
3463 maint info program-spaces
3464 List the program spaces loaded into GDB.
3466 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3467 show remote interrupt-sequence
3468 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3469 as the sequence to the remote target in order to interrupt the execution.
3470 Ctrl-C is a default. Some system prefers BREAK which is high level of
3471 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3472 Magic SysRq g. It is BREAK signal and character 'g'.
3474 set remote interrupt-on-connect [on | off]
3475 show remote interrupt-on-connect
3476 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3477 remote target when gdb connects to it. This is needed when you debug
3480 set remotebreak [on | off]
3482 Deprecated. Use "set/show remote interrupt-sequence" instead.
3484 tvariable $NAME [ = EXP ]
3485 Create or modify a trace state variable.
3488 List trace state variables and their values.
3490 delete tvariable $NAME ...
3491 Delete one or more trace state variables.
3494 Evaluate the given expressions without collecting anything into the
3495 trace buffer. (Valid in tracepoint actions only.)
3497 ftrace FN / FILE:LINE / *ADDR
3498 Define a fast tracepoint at the given function, line, or address.
3500 * New expression syntax
3502 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3503 GDB now parses 0b101010 identically with 42.
3507 set follow-exec-mode new|same
3508 show follow-exec-mode
3509 Control whether GDB reuses the same inferior across an exec call or
3510 creates a new one. This is useful to be able to restart the old
3511 executable after the inferior having done an exec call.
3513 set default-collect EXPR, ...
3514 show default-collect
3515 Define a list of expressions to be collected at each tracepoint.
3516 This is a useful way to ensure essential items are not overlooked,
3517 such as registers or a critical global variable.
3519 set disconnected-tracing
3520 show disconnected-tracing
3521 If set to 1, the target is instructed to continue tracing if it
3522 loses its connection to GDB. If 0, the target is to stop tracing
3525 set circular-trace-buffer
3526 show circular-trace-buffer
3527 If set to on, the target is instructed to use a circular trace buffer
3528 and discard the oldest trace frames instead of stopping the trace due
3529 to a full trace buffer. If set to off, the trace stops when the buffer
3530 fills up. Some targets may not support this.
3532 set script-extension off|soft|strict
3533 show script-extension
3534 If set to "off", the debugger does not perform any script language
3535 recognition, and all sourced files are assumed to be GDB scripts.
3536 If set to "soft" (the default), files are sourced according to
3537 filename extension, falling back to GDB scripts if the first
3539 If set to "strict", files are sourced according to filename extension.
3541 set ada trust-PAD-over-XVS on|off
3542 show ada trust-PAD-over-XVS
3543 If off, activate a workaround against a bug in the debugging information
3544 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3545 the GCC sources for more information about the GNAT encoding and
3546 PAD types in particular). It is always safe to set this option to
3547 off, but this introduces a slight performance penalty. The default
3550 * Python API Improvements
3552 ** GDB provides the new class gdb.LazyString. This is useful in
3553 some pretty-printing cases. The new method gdb.Value.lazy_string
3554 provides a simple way to create objects of this type.
3556 ** The fields returned by gdb.Type.fields now have an
3557 `is_base_class' attribute.
3559 ** The new method gdb.Type.range returns the range of an array type.
3561 ** The new method gdb.parse_and_eval can be used to parse and
3562 evaluate an expression.
3564 * New remote packets
3567 Define a trace state variable.
3570 Get the current value of a trace state variable.
3573 Set desired tracing behavior upon disconnection.
3576 Set the trace buffer to be linear or circular.
3579 Get data about the tracepoints currently in use.
3583 Process record now works correctly with hardware watchpoints.
3585 Multiple bug fixes have been made to the mips-irix port, making it
3586 much more reliable. In particular:
3587 - Debugging threaded applications is now possible again. Previously,
3588 GDB would hang while starting the program, or while waiting for
3589 the program to stop at a breakpoint.
3590 - Attaching to a running process no longer hangs.
3591 - An error occurring while loading a core file has been fixed.
3592 - Changing the value of the PC register now works again. This fixes
3593 problems observed when using the "jump" command, or when calling
3594 a function from GDB, or even when assigning a new value to $pc.
3595 - With the "finish" and "return" commands, the return value for functions
3596 returning a small array is now correctly printed.
3597 - It is now possible to break on shared library code which gets executed
3598 during a shared library init phase (code executed while executing
3599 their .init section). Previously, the breakpoint would have no effect.
3600 - GDB is now able to backtrace through the signal handler for
3601 non-threaded programs.
3603 PIE (Position Independent Executable) programs debugging is now supported.
3604 This includes debugging execution of PIC (Position Independent Code) shared
3605 libraries although for that, it should be possible to run such libraries as an
3608 *** Changes in GDB 7.0
3610 * GDB now has an interface for JIT compilation. Applications that
3611 dynamically generate code can create symbol files in memory and register
3612 them with GDB. For users, the feature should work transparently, and
3613 for JIT developers, the interface is documented in the GDB manual in the
3614 "JIT Compilation Interface" chapter.
3616 * Tracepoints may now be conditional. The syntax is as for
3617 breakpoints; either an "if" clause appended to the "trace" command,
3618 or the "condition" command is available. GDB sends the condition to
3619 the target for evaluation using the same bytecode format as is used
3620 for tracepoint actions.
3622 * The disassemble command now supports: an optional /r modifier, print the
3623 raw instructions in hex as well as in symbolic form, and an optional /m
3624 modifier to print mixed source+assembly.
3626 * Process record and replay
3628 In a architecture environment that supports ``process record and
3629 replay'', ``process record and replay'' target can record a log of
3630 the process execution, and replay it with both forward and reverse
3633 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3634 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3635 set execution-direction {forward|reverse}, for targets that support
3638 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3639 feature is available with a native GDB running on kernel version
3642 * GDB now has support for multi-byte and wide character sets on the
3643 target. Strings whose character type is wchar_t, char16_t, or
3644 char32_t are now correctly printed. GDB supports wide- and unicode-
3645 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3646 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3647 `printf'. This feature requires iconv to work properly; if your
3648 system does not have a working iconv, GDB can use GNU libiconv. See
3649 the installation instructions for more information.
3651 * GDB now supports automatic retrieval of shared library files from
3652 remote targets. To use this feature, specify a system root that begins
3653 with the `remote:' prefix, either via the `set sysroot' command or via
3654 the `--with-sysroot' configure-time option.
3656 * "info sharedlibrary" now takes an optional regex of libraries to show,
3657 and it now reports if a shared library has no debugging information.
3659 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3660 now complete on file names.
3662 * When completing in expressions, gdb will attempt to limit
3663 completions to allowable structure or union fields, where appropriate.
3664 For instance, consider:
3666 # struct example { int f1; double f2; };
3667 # struct example variable;
3670 If the user types TAB at the end of this command line, the available
3671 completions will be "f1" and "f2".
3673 * Inlined functions are now supported. They show up in backtraces, and
3674 the "step", "next", and "finish" commands handle them automatically.
3676 * GDB now supports the token-splicing (##) and stringification (#)
3677 operators when expanding macros. It also supports variable-arity
3680 * GDB now supports inspecting extra signal information, exported by
3681 the new $_siginfo convenience variable. The feature is currently
3682 implemented on linux ARM, i386 and amd64.
3684 * GDB can now display the VFP floating point registers and NEON vector
3685 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3686 can provide these registers (requires Linux 2.6.30 or later). Remote
3687 and simulator targets may also provide them.
3689 * New remote packets
3692 Search memory for a sequence of bytes.
3695 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3696 operation over reliable transport links. Use of this packet is
3697 controlled by the `set remote noack-packet' command.
3700 Kill the process with the specified process ID. Use this in preference
3701 to `k' when multiprocess protocol extensions are supported.
3704 Obtains additional operating system information
3708 Read or write additional signal information.
3710 * Removed remote protocol undocumented extension
3712 An undocumented extension to the remote protocol's `S' stop reply
3713 packet that permited the stub to pass a process id was removed.
3714 Remote servers should use the `T' stop reply packet instead.
3716 * GDB now supports multiple function calling conventions according to the
3717 DWARF-2 DW_AT_calling_convention function attribute.
3719 * The SH target utilizes the aforementioned change to distinguish between gcc
3720 and Renesas calling convention. It also adds the new CLI commands
3721 `set/show sh calling-convention'.
3723 * GDB can now read compressed debug sections, as produced by GNU gold
3724 with the --compress-debug-sections=zlib flag.
3726 * 64-bit core files are now supported on AIX.
3728 * Thread switching is now supported on Tru64.
3730 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3731 which will be allocated using malloc later in program execution.
3733 * The qXfer:libraries:read remote procotol packet now allows passing a
3734 list of section offsets.
3736 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3737 conditions handling signals delivered during attach or thread creation
3738 have also been fixed.
3740 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3741 From the user's standpoint, all unqualified instances of True and False
3742 are treated as the standard definitions, regardless of context.
3744 * GDB now parses C++ symbol and type names more flexibly. For
3747 template<typename T> class C { };
3750 GDB will now correctly handle all of:
3752 ptype C<char const *>
3753 ptype C<char const*>
3754 ptype C<const char *>
3755 ptype C<const char*>
3757 * New features in the GDB remote stub, gdbserver
3759 - The "--wrapper" command-line argument tells gdbserver to use a
3760 wrapper program to launch programs for debugging.
3762 - On PowerPC and S/390 targets, it is now possible to use a single
3763 gdbserver executable to debug both 32-bit and 64-bit programs.
3764 (This requires gdbserver itself to be built as a 64-bit executable.)
3766 - gdbserver uses the new noack protocol mode for TCP connections to
3767 reduce communications latency, if also supported and enabled in GDB.
3769 - Support for the sparc64-linux-gnu target is now included in
3772 - The amd64-linux build of gdbserver now supports debugging both
3773 32-bit and 64-bit programs.
3775 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3776 now support hardware watchpoints, and will use them automatically
3781 GDB now has support for scripting using Python. Whether this is
3782 available is determined at configure time.
3784 New GDB commands can now be written in Python.
3786 * Ada tasking support
3788 Ada tasks can now be inspected in GDB. The following commands have
3792 Print the list of Ada tasks.
3794 Print detailed information about task number N.
3796 Print the task number of the current task.
3798 Switch the context of debugging to task number N.
3800 * Support for user-defined prefixed commands. The "define" command can
3801 add new commands to existing prefixes, e.g. "target".
3803 * Multi-inferior, multi-process debugging.
3805 GDB now has generalized support for multi-inferior debugging. See
3806 "Debugging Multiple Inferiors" in the manual for more information.
3807 Although availability still depends on target support, the command
3808 set is more uniform now. The GNU/Linux specific multi-forks support
3809 has been migrated to this new framework. This implied some user
3810 visible changes; see "New commands" and also "Removed commands"
3813 * Target descriptions can now describe the target OS ABI. See the
3814 "Target Description Format" section in the user manual for more
3817 * Target descriptions can now describe "compatible" architectures
3818 to indicate that the target can execute applications for a different
3819 architecture in addition to those for the main target architecture.
3820 See the "Target Description Format" section in the user manual for
3823 * Multi-architecture debugging.
3825 GDB now includes general supports for debugging applications on
3826 hybrid systems that use more than one single processor architecture
3827 at the same time. Each such hybrid architecture still requires
3828 specific support to be added. The only hybrid architecture supported
3829 in this version of GDB is the Cell Broadband Engine.
3831 * GDB now supports integrated debugging of Cell/B.E. applications that
3832 use both the PPU and SPU architectures. To enable support for hybrid
3833 Cell/B.E. debugging, you need to configure GDB to support both the
3834 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3835 --enable-targets configure option.
3837 * Non-stop mode debugging.
3839 For some targets, GDB now supports an optional mode of operation in
3840 which you can examine stopped threads while other threads continue
3841 to execute freely. This is referred to as non-stop mode, with the
3842 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3843 section in the user manual for more information.
3845 To be able to support remote non-stop debugging, a remote stub needs
3846 to implement the non-stop mode remote protocol extensions, as
3847 described in the "Remote Non-Stop" section of the user manual. The
3848 GDB remote stub, gdbserver, has been adjusted to support these
3849 extensions on linux targets.
3851 * New commands (for set/show, see "New options" below)
3853 catch syscall [NAME(S) | NUMBER(S)]
3854 Catch system calls. Arguments, which should be names of system
3855 calls or their numbers, mean catch only those syscalls. Without
3856 arguments, every syscall will be caught. When the inferior issues
3857 any of the specified syscalls, GDB will stop and announce the system
3858 call, both when it is called and when its call returns. This
3859 feature is currently available with a native GDB running on the
3860 Linux Kernel, under the following architectures: x86, x86_64,
3861 PowerPC and PowerPC64.
3863 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3865 Search memory for a sequence of bytes.
3867 maint set python print-stack
3868 maint show python print-stack
3869 Show a stack trace when an error is encountered in a Python script.
3872 Invoke CODE by passing it to the Python interpreter.
3877 These allow macros to be defined, undefined, and listed
3881 Show operating system information about processes.
3884 List the inferiors currently under GDB's control.
3887 Switch focus to inferior number NUM.
3890 Detach from inferior number NUM.
3893 Kill inferior number NUM.
3897 set spu stop-on-load
3898 show spu stop-on-load
3899 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3901 set spu auto-flush-cache
3902 show spu auto-flush-cache
3903 Control whether to automatically flush the software-managed cache
3904 during Cell/B.E. debugging.
3906 set sh calling-convention
3907 show sh calling-convention
3908 Control the calling convention used when calling SH target functions.
3911 show debug timestamp
3912 Control display of timestamps with GDB debugging output.
3914 set disassemble-next-line
3915 show disassemble-next-line
3916 Control display of disassembled source lines or instructions when
3919 set remote noack-packet
3920 show remote noack-packet
3921 Set/show the use of remote protocol QStartNoAckMode packet. See above
3922 under "New remote packets."
3924 set remote query-attached-packet
3925 show remote query-attached-packet
3926 Control use of remote protocol `qAttached' (query-attached) packet.
3928 set remote read-siginfo-object
3929 show remote read-siginfo-object
3930 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3933 set remote write-siginfo-object
3934 show remote write-siginfo-object
3935 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3938 set remote reverse-continue
3939 show remote reverse-continue
3940 Control use of remote protocol 'bc' (reverse-continue) packet.
3942 set remote reverse-step
3943 show remote reverse-step
3944 Control use of remote protocol 'bs' (reverse-step) packet.
3946 set displaced-stepping
3947 show displaced-stepping
3948 Control displaced stepping mode. Displaced stepping is a way to
3949 single-step over breakpoints without removing them from the debuggee.
3950 Also known as "out-of-line single-stepping".
3953 show debug displaced
3954 Control display of debugging info for displaced stepping.
3956 maint set internal-error
3957 maint show internal-error
3958 Control what GDB does when an internal error is detected.
3960 maint set internal-warning
3961 maint show internal-warning
3962 Control what GDB does when an internal warning is detected.
3967 Use a wrapper program to launch programs for debugging.
3969 set multiple-symbols (all|ask|cancel)
3970 show multiple-symbols
3971 The value of this variable can be changed to adjust the debugger behavior
3972 when an expression or a breakpoint location contains an ambiguous symbol
3973 name (an overloaded function name, for instance).
3975 set breakpoint always-inserted
3976 show breakpoint always-inserted
3977 Keep breakpoints always inserted in the target, as opposed to inserting
3978 them when resuming the target, and removing them when the target stops.
3979 This option can improve debugger performance on slow remote targets.
3981 set arm fallback-mode (arm|thumb|auto)
3982 show arm fallback-mode
3983 set arm force-mode (arm|thumb|auto)
3985 These commands control how ARM GDB determines whether instructions
3986 are ARM or Thumb. The default for both settings is auto, which uses
3987 the current CPSR value for instructions without symbols; previous
3988 versions of GDB behaved as if "set arm fallback-mode arm".
3990 set disable-randomization
3991 show disable-randomization
3992 Standalone programs run with the virtual address space randomization enabled
3993 by default on some platforms. This option keeps the addresses stable across
3994 multiple debugging sessions.
3998 Control whether other threads are stopped or not when some thread hits
4003 Requests that asynchronous execution is enabled in the target, if available.
4004 In this case, it's possible to resume target in the background, and interact
4005 with GDB while the target is running. "show target-async" displays the
4006 current state of asynchronous execution of the target.
4008 set target-wide-charset
4009 show target-wide-charset
4010 The target-wide-charset is the name of the character set that GDB
4011 uses when printing characters whose type is wchar_t.
4013 set tcp auto-retry (on|off)
4015 set tcp connect-timeout
4016 show tcp connect-timeout
4017 These commands allow GDB to retry failed TCP connections to a remote stub
4018 with a specified timeout period; this is useful if the stub is launched
4019 in parallel with GDB but may not be ready to accept connections immediately.
4021 set libthread-db-search-path
4022 show libthread-db-search-path
4023 Control list of directories which GDB will search for appropriate
4026 set schedule-multiple (on|off)
4027 show schedule-multiple
4028 Allow GDB to resume all threads of all processes or only threads of
4029 the current process.
4033 Use more aggressive caching for accesses to the stack. This improves
4034 performance of remote debugging (particularly backtraces) without
4035 affecting correctness.
4037 set interactive-mode (on|off|auto)
4038 show interactive-mode
4039 Control whether GDB runs in interactive mode (on) or not (off).
4040 When in interactive mode, GDB waits for the user to answer all
4041 queries. Otherwise, GDB does not wait and assumes the default
4042 answer. When set to auto (the default), GDB determines which
4043 mode to use based on the stdin settings.
4048 For program forks, this is replaced by the new more generic `info
4049 inferiors' command. To list checkpoints, you can still use the
4050 `info checkpoints' command, which was an alias for the `info forks'
4054 Replaced by the new `inferior' command. To switch between
4055 checkpoints, you can still use the `restart' command, which was an
4056 alias for the `fork' command.
4059 This is removed, since some targets don't have a notion of
4060 processes. To switch between processes, you can still use the
4061 `inferior' command using GDB's own inferior number.
4064 For program forks, this is replaced by the new more generic `kill
4065 inferior' command. To delete a checkpoint, you can still use the
4066 `delete checkpoint' command, which was an alias for the `delete
4070 For program forks, this is replaced by the new more generic `detach
4071 inferior' command. To detach a checkpoint, you can still use the
4072 `detach checkpoint' command, which was an alias for the `detach
4075 * New native configurations
4077 x86/x86_64 Darwin i[34567]86-*-darwin*
4079 x86_64 MinGW x86_64-*-mingw*
4083 Lattice Mico32 lm32-*
4084 x86 DICOS i[34567]86-*-dicos*
4085 x86_64 DICOS x86_64-*-dicos*
4088 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4089 (mingw32ce) debugging.
4095 These commands were actually not implemented on any target.
4097 *** Changes in GDB 6.8
4099 * New native configurations
4101 NetBSD/hppa hppa*-*netbsd*
4102 Xtensa GNU/Linux xtensa*-*-linux*
4106 NetBSD/hppa hppa*-*-netbsd*
4107 Xtensa GNU/Lunux xtensa*-*-linux*
4109 * Change in command line behavior -- corefiles vs. process ids.
4111 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4112 attaching to process NUMBER fails, GDB no longer attempts to open a
4113 core file named NUMBER. Attaching to a program using the -c option
4114 is no longer supported. Instead, use the '-p' or '--pid' options.
4116 * GDB can now be built as a native debugger for debugging Windows x86
4117 (mingw32) Portable Executable (PE) programs.
4119 * Pending breakpoints no longer change their number when their address
4122 * GDB now supports breakpoints with multiple locations,
4123 including breakpoints on C++ constructors, inside C++ templates,
4124 and in inlined functions.
4126 * GDB's ability to debug optimized code has been improved. GDB more
4127 accurately identifies function bodies and lexical blocks that occupy
4128 more than one contiguous range of addresses.
4130 * Target descriptions can now describe registers for PowerPC.
4132 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4133 registers on PowerPC targets.
4135 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4136 targets even when the libthread_db library is not available.
4138 * The GDB remote stub, gdbserver, now supports the new file transfer
4139 commands (remote put, remote get, and remote delete).
4141 * The GDB remote stub, gdbserver, now supports run and attach in
4142 extended-remote mode.
4144 * hppa*64*-*-hpux11* target broken
4145 The debugger is unable to start a program and fails with the following
4146 error: "Error trying to get information about dynamic linker".
4147 The gdb-6.7 release is also affected.
4149 * GDB now supports the --enable-targets= configure option to allow
4150 building a single GDB executable that supports multiple remote
4151 target architectures.
4153 * GDB now supports debugging C and C++ programs which use the
4154 Decimal Floating Point extension. In addition, the PowerPC target
4155 now has a set of pseudo-registers to inspect decimal float values
4156 stored in two consecutive float registers.
4158 * The -break-insert MI command can optionally create pending
4161 * Improved support for debugging Ada
4162 Many improvements to the Ada language support have been made. These
4164 - Better support for Ada2005 interface types
4165 - Improved handling of arrays and slices in general
4166 - Better support for Taft-amendment types
4167 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4169 - Improved command completion in Ada
4172 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4177 set print frame-arguments (all|scalars|none)
4178 show print frame-arguments
4179 The value of this variable can be changed to control which argument
4180 values should be printed by the debugger when displaying a frame.
4185 Transfer files to and from a remote target, and delete remote files.
4192 Transfer files to and from a remote target, and delete remote files.
4194 * New remote packets
4201 Open, close, read, write, and delete files on the remote system.
4204 Attach to an existing process on the remote system, in extended-remote
4208 Run a new process on the remote system, in extended-remote mode.
4210 *** Changes in GDB 6.7
4212 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4213 bfd, libiberty and opcodes, as revealed by static analysis donated by
4214 Coverity, Inc. (http://scan.coverity.com).
4216 * When looking up multiply-defined global symbols, GDB will now prefer the
4217 symbol definition in the current shared library if it was built using the
4218 -Bsymbolic linker option.
4220 * When the Text User Interface (TUI) is not configured, GDB will now
4221 recognize the -tui command-line option and print a message that the TUI
4224 * The GDB remote stub, gdbserver, now has lower overhead for high
4225 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4227 * GDB for MIPS targets now autodetects whether a remote target provides
4228 32-bit or 64-bit register values.
4230 * Support for C++ member pointers has been improved.
4232 * GDB now understands XML target descriptions, which specify the
4233 target's overall architecture. GDB can read a description from
4234 a local file or over the remote serial protocol.
4236 * Vectors of single-byte data use a new integer type which is not
4237 automatically displayed as character or string data.
4239 * The /s format now works with the print command. It displays
4240 arrays of single-byte integers and pointers to single-byte integers
4243 * Target descriptions can now describe target-specific registers,
4244 for architectures which have implemented the support (currently
4245 only ARM, M68K, and MIPS).
4247 * GDB and the GDB remote stub, gdbserver, now support the XScale
4250 * The GDB remote stub, gdbserver, has been updated to support
4251 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4252 has been rewritten to use the standard GDB remote protocol.
4254 * GDB can now step into C++ functions which are called through thunks.
4256 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4258 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4259 layout. It also supports a TextSeg= and DataSeg= response when only
4260 segment base addresses (rather than offsets) are available.
4262 * The /i format now outputs any trailing branch delay slot instructions
4263 immediately following the last instruction within the count specified.
4265 * The GDB remote protocol "T" stop reply packet now supports a
4266 "library" response. Combined with the new "qXfer:libraries:read"
4267 packet, this response allows GDB to debug shared libraries on targets
4268 where the operating system manages the list of loaded libraries (e.g.
4269 Windows and SymbianOS).
4271 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4272 (DLLs) on Windows and Windows CE targets.
4274 * GDB now supports a faster verification that a .debug file matches its binary
4275 according to its build-id signature, if the signature is present.
4281 Enable or disable hardware flow control (RTS/CTS) on the serial port
4282 when debugging using remote targets.
4284 set mem inaccessible-by-default
4285 show mem inaccessible-by-default
4286 If the target supplies a memory map, for instance via the remote
4287 protocol's "qXfer:memory-map:read" packet, setting this variable
4288 prevents GDB from accessing memory outside the memory map. This
4289 is useful for targets with memory mapped registers or which react
4290 badly to accesses of unmapped address space.
4292 set breakpoint auto-hw
4293 show breakpoint auto-hw
4294 If the target supplies a memory map, for instance via the remote
4295 protocol's "qXfer:memory-map:read" packet, setting this variable
4296 lets GDB use hardware breakpoints automatically for memory regions
4297 where it can not use software breakpoints. This covers both the
4298 "break" command and internal breakpoints used for other commands
4299 including "next" and "finish".
4302 catch exception unhandled
4303 Stop the program execution when Ada exceptions are raised.
4306 Stop the program execution when an Ada assertion failed.
4310 Set an alternate system root for target files. This is a more
4311 general version of "set solib-absolute-prefix", which is now
4312 an alias to "set sysroot".
4315 Provide extended SPU facility status information. This set of
4316 commands is available only when debugging the Cell/B.E. SPU
4319 * New native configurations
4321 OpenBSD/sh sh*-*openbsd*
4324 unset tdesc filename
4326 Use the specified local file as an XML target description, and do
4327 not query the target for its built-in description.
4331 OpenBSD/sh sh*-*-openbsd*
4332 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4333 Toshiba Media Processor mep-elf
4335 * New remote packets
4338 Ignore the specified signals; pass them directly to the debugged program
4339 without stopping other threads or reporting them to GDB.
4341 qXfer:features:read:
4342 Read an XML target description from the target, which describes its
4347 Read or write contents of an spufs file on the target system. These
4348 packets are available only on the Cell/B.E. SPU architecture.
4350 qXfer:libraries:read:
4351 Report the loaded shared libraries. Combined with new "T" packet
4352 response, this packet allows GDB to debug shared libraries on
4353 targets where the operating system manages the list of loaded
4354 libraries (e.g. Windows and SymbianOS).
4358 Support for these obsolete configurations has been removed.
4366 i[34567]86-*-lynxos*
4367 i[34567]86-*-netware*
4368 i[34567]86-*-sco3.2v5*
4369 i[34567]86-*-sco3.2v4*
4371 i[34567]86-*-sysv4.2*
4374 i[34567]86-*-unixware2*
4375 i[34567]86-*-unixware*
4384 * Other removed features
4391 Various m68k-only ROM monitors.
4398 Various Renesas ROM monitors and debugging interfaces for SH and
4403 Support for a Macraigor serial interface to on-chip debugging.
4404 GDB does not directly support the newer parallel or USB
4409 A debug information format. The predecessor to DWARF 2 and
4410 DWARF 3, which are still supported.
4412 Support for the HP aCC compiler on HP-UX/PA-RISC
4414 SOM-encapsulated symbolic debugging information, automatic
4415 invocation of pxdb, and the aCC custom C++ ABI. This does not
4416 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4417 with aCC can still be debugged on an assembly level.
4419 MIPS ".pdr" sections
4421 A MIPS-specific format used to describe stack frame layout
4422 in debugging information.
4426 GDB could work with an older version of Guile to debug
4427 the interpreter and Scheme programs running in it.
4429 set mips stack-arg-size
4430 set mips saved-gpreg-size
4432 Use "set mips abi" to control parameter passing for MIPS.
4434 *** Changes in GDB 6.6
4439 Cell Broadband Engine SPU spu-elf
4441 * GDB can now be configured as a cross-debugger targeting native Windows
4442 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4443 running on a Windows system over TCP/IP to debug Windows programs.
4445 * The GDB remote stub, gdbserver, has been updated to support Windows and
4446 Cygwin debugging. Both single-threaded and multi-threaded programs are
4449 * The "set trust-readonly-sections" command works again. This command was
4450 broken in GDB 6.3, 6.4, and 6.5.
4452 * The "load" command now supports writing to flash memory, if the remote
4453 stub provides the required support.
4455 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4456 longer requires symbolic debug information (e.g. DWARF-2).
4461 unset substitute-path
4462 show substitute-path
4463 Manage a list of substitution rules that GDB uses to rewrite the name
4464 of the directories where the sources are located. This can be useful
4465 for instance when the sources were moved to a different location
4466 between compilation and debugging.
4470 Print each CLI command as it is executed. Each command is prefixed with
4471 a number of `+' symbols representing the nesting depth.
4472 The source command now has a `-v' option to enable the same feature.
4476 The ARM Demon monitor support (RDP protocol, "target rdp").
4478 Kernel Object Display, an embedded debugging feature which only worked with
4479 an obsolete version of Cisco IOS.
4481 The 'set download-write-size' and 'show download-write-size' commands.
4483 * New remote packets
4486 Tell a stub about GDB client features, and request remote target features.
4487 The first feature implemented is PacketSize, which allows the target to
4488 specify the size of packets it can handle - to minimize the number of
4489 packets required and improve performance when connected to a remote
4493 Fetch an OS auxilliary vector from the remote stub. This packet is a
4494 more efficient replacement for qPart:auxv:read.
4496 qXfer:memory-map:read:
4497 Fetch a memory map from the remote stub, including information about
4498 RAM, ROM, and flash memory devices.
4503 Erase and program a flash memory device.
4505 * Removed remote packets
4508 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4509 used it, and only gdbserver implemented it.
4511 *** Changes in GDB 6.5
4515 Renesas M32C/M16C m32c-elf
4517 Morpho Technologies ms1 ms1-elf
4521 init-if-undefined Initialize a convenience variable, but
4522 only if it doesn't already have a value.
4524 The following commands are presently only implemented for native GNU/Linux:
4526 checkpoint Save a snapshot of the program state.
4528 restart <n> Return the program state to a
4529 previously saved state.
4531 info checkpoints List currently saved checkpoints.
4533 delete-checkpoint <n> Delete a previously saved checkpoint.
4535 set|show detach-on-fork Tell gdb whether to detach from a newly
4536 forked process, or to keep debugging it.
4538 info forks List forks of the user program that
4539 are available to be debugged.
4541 fork <n> Switch to debugging one of several
4542 forks of the user program that are
4543 available to be debugged.
4545 delete-fork <n> Delete a fork from the list of forks
4546 that are available to be debugged (and
4547 kill the forked process).
4549 detach-fork <n> Delete a fork from the list of forks
4550 that are available to be debugged (and
4551 allow the process to continue).
4555 Morpho Technologies ms2 ms1-elf
4557 * Improved Windows host support
4559 GDB now builds as a cross debugger hosted on i686-mingw32, including
4560 native console support, and remote communications using either
4561 network sockets or serial ports.
4563 * Improved Modula-2 language support
4565 GDB can now print most types in the Modula-2 syntax. This includes:
4566 basic types, set types, record types, enumerated types, range types,
4567 pointer types and ARRAY types. Procedure var parameters are correctly
4568 printed and hexadecimal addresses and character constants are also
4569 written in the Modula-2 syntax. Best results can be obtained by using
4570 GNU Modula-2 together with the -gdwarf-2 command line option.
4574 The ARM rdi-share module.
4576 The Netware NLM debug server.
4578 *** Changes in GDB 6.4
4580 * New native configurations
4582 OpenBSD/arm arm*-*-openbsd*
4583 OpenBSD/mips64 mips64-*-openbsd*
4587 Morpho Technologies ms1 ms1-elf
4589 * New command line options
4591 --batch-silent As for --batch, but totally silent.
4592 --return-child-result The debugger will exist with the same value
4593 the child (debugged) program exited with.
4594 --eval-command COMMAND, -ex COMMAND
4595 Execute a single GDB CLI command. This may be
4596 specified multiple times and in conjunction
4597 with the --command (-x) option.
4599 * Deprecated commands removed
4601 The following commands, that were deprecated in 2000, have been
4605 set|show arm disassembly-flavor set|show arm disassembler
4606 othernames set arm disassembler
4607 set|show remotedebug set|show debug remote
4608 set|show archdebug set|show debug arch
4609 set|show eventdebug set|show debug event
4612 * New BSD user-level threads support
4614 It is now possible to debug programs using the user-level threads
4615 library on OpenBSD and FreeBSD. Currently supported (target)
4618 FreeBSD/amd64 x86_64-*-freebsd*
4619 FreeBSD/i386 i386-*-freebsd*
4620 OpenBSD/i386 i386-*-openbsd*
4622 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4623 are not yet supported.
4625 * New support for Matsushita MN10300 w/sim added
4626 (Work in progress). mn10300-elf.
4628 * REMOVED configurations and files
4630 VxWorks and the XDR protocol *-*-vxworks
4631 Motorola MCORE mcore-*-*
4632 National Semiconductor NS32000 ns32k-*-*
4634 * New "set print array-indexes" command
4636 After turning this setting "on", GDB prints the index of each element
4637 when displaying arrays. The default is "off" to preserve the previous
4640 * VAX floating point support
4642 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4644 * User-defined command support
4646 In addition to using $arg0..$arg9 for argument passing, it is now possible
4647 to use $argc to determine now many arguments have been passed. See the
4648 section on user-defined commands in the user manual for more information.
4650 *** Changes in GDB 6.3:
4652 * New command line option
4654 GDB now accepts -l followed by a number to set the timeout for remote
4657 * GDB works with GCC -feliminate-dwarf2-dups
4659 GDB now supports a more compact representation of DWARF-2 debug
4660 information using DW_FORM_ref_addr references. These are produced
4661 by GCC with the option -feliminate-dwarf2-dups and also by some
4662 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4663 to use -feliminate-dwarf2-dups.
4665 * Internationalization
4667 When supported by the host system, GDB will be built with
4668 internationalization (libintl). The task of marking up the sources is
4669 continued, we're looking forward to our first translation.
4673 Initial support for debugging programs compiled with the GNAT
4674 implementation of the Ada programming language has been integrated
4675 into GDB. In this release, support is limited to expression evaluation.
4677 * New native configurations
4679 GNU/Linux/m32r m32r-*-linux-gnu
4683 GDB's remote protocol now includes support for the 'p' packet. This
4684 packet is used to fetch individual registers from a remote inferior.
4686 * END-OF-LIFE registers[] compatibility module
4688 GDB's internal register infrastructure has been completely rewritten.
4689 The new infrastructure making possible the implementation of key new
4690 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4693 GDB 6.3 will be the last release to include the the registers[]
4694 compatibility module that allowed out-of-date configurations to
4695 continue to work. This change directly impacts the following
4705 powerpc bdm protocol
4707 Unless there is activity to revive these configurations, they will be
4708 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4710 * OBSOLETE configurations and files
4712 Configurations that have been declared obsolete in this release have
4713 been commented out. Unless there is activity to revive these
4714 configurations, the next release of GDB will have their sources
4715 permanently REMOVED.
4724 *** Changes in GDB 6.2.1:
4726 * MIPS `break main; run' gave an heuristic-fence-post warning
4728 When attempting to run even a simple program, a warning about
4729 heuristic-fence-post being hit would be reported. This problem has
4732 * MIPS IRIX 'long double' crashed GDB
4734 When examining a long double variable, GDB would get a segmentation
4735 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4736 IRIX long double values).
4740 A bug in the VAX stack code was causing problems with the "next"
4741 command. This problem has been fixed.
4743 *** Changes in GDB 6.2:
4745 * Fix for ``many threads''
4747 On GNU/Linux systems that use the NPTL threads library, a program
4748 rapidly creating and deleting threads would confuse GDB leading to the
4751 ptrace: No such process.
4752 thread_db_get_info: cannot get thread info: generic error
4754 This problem has been fixed.
4756 * "-async" and "-noasync" options removed.
4758 Support for the broken "-noasync" option has been removed (it caused
4761 * New ``start'' command.
4763 This command runs the program until the begining of the main procedure.
4765 * New BSD Kernel Data Access Library (libkvm) interface
4767 Using ``target kvm'' it is now possible to debug kernel core dumps and
4768 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4769 platforms. Currently supported (native-only) configurations are:
4771 FreeBSD/amd64 x86_64-*-freebsd*
4772 FreeBSD/i386 i?86-*-freebsd*
4773 NetBSD/i386 i?86-*-netbsd*
4774 NetBSD/m68k m68*-*-netbsd*
4775 NetBSD/sparc sparc-*-netbsd*
4776 OpenBSD/amd64 x86_64-*-openbsd*
4777 OpenBSD/i386 i?86-*-openbsd*
4778 OpenBSD/m68k m68*-openbsd*
4779 OpenBSD/sparc sparc-*-openbsd*
4781 * Signal trampoline code overhauled
4783 Many generic problems with GDB's signal handling code have been fixed.
4784 These include: backtraces through non-contiguous stacks; recognition
4785 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4786 call; backtrace through a signal trampoline; step into and out of
4787 signal handlers; and single-stepping in the signal trampoline.
4789 Please note that kernel bugs are a limiting factor here. These
4790 features have been shown to work on an s390 GNU/Linux system that
4791 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4793 * Cygwin support for DWARF 2 added.
4795 * New native configurations
4797 GNU/Linux/hppa hppa*-*-linux*
4798 OpenBSD/hppa hppa*-*-openbsd*
4799 OpenBSD/m68k m68*-*-openbsd*
4800 OpenBSD/m88k m88*-*-openbsd*
4801 OpenBSD/powerpc powerpc-*-openbsd*
4802 NetBSD/vax vax-*-netbsd*
4803 OpenBSD/vax vax-*-openbsd*
4805 * END-OF-LIFE frame compatibility module
4807 GDB's internal frame infrastructure has been completely rewritten.
4808 The new infrastructure making it possible to support key new features
4809 including DWARF 2 Call Frame Information. To aid in the task of
4810 migrating old configurations to this new infrastructure, a
4811 compatibility module, that allowed old configurations to continue to
4812 work, was also included.
4814 GDB 6.2 will be the last release to include this frame compatibility
4815 module. This change directly impacts the following configurations:
4825 Unless there is activity to revive these configurations, they will be
4826 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4828 * REMOVED configurations and files
4830 Sun 3, running SunOS 3 m68*-*-sunos3*
4831 Sun 3, running SunOS 4 m68*-*-sunos4*
4832 Sun 2, running SunOS 3 m68000-*-sunos3*
4833 Sun 2, running SunOS 4 m68000-*-sunos4*
4834 Motorola 680x0 running LynxOS m68*-*-lynxos*
4835 AT&T 3b1/Unix pc m68*-att-*
4836 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4837 decstation mips-dec-* mips-little-*
4838 riscos mips-*-riscos* mips-*-sysv*
4839 sonymips mips-sony-*
4840 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4842 *** Changes in GDB 6.1.1:
4844 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4846 The TUI (Text-mode User Interface) is now built as part of a default
4847 GDB configuration. It is enabled by either selecting the TUI with the
4848 command line option "-i=tui" or by running the separate "gdbtui"
4849 program. For more information on the TUI, see the manual "Debugging
4852 * Pending breakpoint support (also included in GDB 6.1)
4854 Support has been added to allow you to specify breakpoints in shared
4855 libraries that have not yet been loaded. If a breakpoint location
4856 cannot be found, and the "breakpoint pending" option is set to auto,
4857 GDB queries you if you wish to make the breakpoint pending on a future
4858 shared-library load. If and when GDB resolves the breakpoint symbol,
4859 the pending breakpoint is removed as one or more regular breakpoints
4862 Pending breakpoints are very useful for GCJ Java debugging.
4864 * Fixed ISO-C build problems
4866 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4867 non ISO-C code that stopped them being built using a more strict ISO-C
4868 compiler (e.g., IBM's C compiler).
4870 * Fixed build problem on IRIX 5
4872 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4873 wasn't able to compile compile on an IRIX 5 system.
4875 * Added execute permission to gdb/gdbserver/configure
4877 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4878 permission. This bug would cause configure to fail on a number of
4879 systems (Solaris, IRIX). Ref: server/519.
4881 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4883 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4884 has been updated to use constant array sizes.
4886 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4888 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4889 its generated DWARF Call Frame Info. This encoding was causing GDB to
4890 panic, that panic has been fixed. Ref: gdb/1628.
4892 * Fixed a problem when examining parameters in shared library code.
4894 When examining parameters in optimized shared library code generated
4895 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4896 not available''. GDB now correctly displays the variable's value.
4898 *** Changes in GDB 6.1:
4900 * Removed --with-mmalloc
4902 Support for the mmalloc memory manager has been removed, as it
4903 conflicted with the internal gdb byte cache.
4905 * Changes in AMD64 configurations
4907 The AMD64 target now includes the %cs and %ss registers. As a result
4908 the AMD64 remote protocol has changed; this affects the floating-point
4909 and SSE registers. If you rely on those registers for your debugging,
4910 you should upgrade gdbserver on the remote side.
4912 * Revised SPARC target
4914 The SPARC target has been completely revised, incorporating the
4915 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4916 support for LynxOS and SunOS 4 has been dropped. Calling functions
4917 from within GDB on operating systems with a non-executable stack
4918 (Solaris, OpenBSD) now works.
4922 GDB has a new C++ demangler which does a better job on the mangled
4923 names generated by current versions of g++. It also runs faster, so
4924 with this and other changes gdb should now start faster on large C++
4927 * DWARF 2 Location Expressions
4929 GDB support for location expressions has been extended to support function
4930 arguments and frame bases. Older versions of GDB could crash when they
4933 * C++ nested types and namespaces
4935 GDB's support for nested types and namespaces in C++ has been
4936 improved, especially if you use the DWARF 2 debugging format. (This
4937 is the default for recent versions of GCC on most platforms.)
4938 Specifically, if you have a class "Inner" defined within a class or
4939 namespace "Outer", then GDB realizes that the class's name is
4940 "Outer::Inner", not simply "Inner". This should greatly reduce the
4941 frequency of complaints about not finding RTTI symbols. In addition,
4942 if you are stopped at inside of a function defined within a namespace,
4943 GDB modifies its name lookup accordingly.
4945 * New native configurations
4947 NetBSD/amd64 x86_64-*-netbsd*
4948 OpenBSD/amd64 x86_64-*-openbsd*
4949 OpenBSD/alpha alpha*-*-openbsd*
4950 OpenBSD/sparc sparc-*-openbsd*
4951 OpenBSD/sparc64 sparc64-*-openbsd*
4953 * New debugging protocols
4955 M32R with SDI protocol m32r-*-elf*
4957 * "set prompt-escape-char" command deleted.
4959 The command "set prompt-escape-char" has been deleted. This command,
4960 and its very obscure effet on GDB's prompt, was never documented,
4961 tested, nor mentioned in the NEWS file.
4963 * OBSOLETE configurations and files
4965 Configurations that have been declared obsolete in this release have
4966 been commented out. Unless there is activity to revive these
4967 configurations, the next release of GDB will have their sources
4968 permanently REMOVED.
4970 Sun 3, running SunOS 3 m68*-*-sunos3*
4971 Sun 3, running SunOS 4 m68*-*-sunos4*
4972 Sun 2, running SunOS 3 m68000-*-sunos3*
4973 Sun 2, running SunOS 4 m68000-*-sunos4*
4974 Motorola 680x0 running LynxOS m68*-*-lynxos*
4975 AT&T 3b1/Unix pc m68*-att-*
4976 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4977 decstation mips-dec-* mips-little-*
4978 riscos mips-*-riscos* mips-*-sysv*
4979 sonymips mips-sony-*
4980 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4982 * REMOVED configurations and files
4984 SGI Irix-4.x mips-sgi-irix4 or iris4
4985 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4986 Z8000 simulator z8k-zilog-none or z8ksim
4987 Matsushita MN10200 w/simulator mn10200-*-*
4988 H8/500 simulator h8500-hitachi-hms or h8500hms
4989 HP/PA running BSD hppa*-*-bsd*
4990 HP/PA running OSF/1 hppa*-*-osf*
4991 HP/PA Pro target hppa*-*-pro*
4992 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4993 386BSD i[3456]86-*-bsd*
4994 Sequent family i[3456]86-sequent-sysv4*
4995 i[3456]86-sequent-sysv*
4996 i[3456]86-sequent-bsd*
4997 SPARC running LynxOS sparc-*-lynxos*
4998 SPARC running SunOS 4 sparc-*-sunos4*
4999 Tsqware Sparclet sparclet-*-*
5000 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5002 *** Changes in GDB 6.0:
5006 Support for debugging the Objective-C programming language has been
5007 integrated into GDB.
5009 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5011 DWARF 2's Call Frame Information makes available compiler generated
5012 information that more exactly describes the program's run-time stack.
5013 By using this information, GDB is able to provide more robust stack
5016 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5017 have been updated to use a new backtrace mechanism which includes
5018 DWARF 2 CFI support.
5022 GDB's remote protocol has been extended to include support for hosted
5023 file I/O (where the remote target uses GDB's file system). See GDB's
5024 remote protocol documentation for details.
5026 * All targets using the new architecture framework.
5028 All of GDB's targets have been updated to use the new internal
5029 architecture framework. The way is now open for future GDB releases
5030 to include cross-architecture native debugging support (i386 on amd64,
5033 * GNU/Linux's Thread Local Storage (TLS)
5035 GDB now includes support for for the GNU/Linux implementation of
5036 per-thread variables.
5038 * GNU/Linux's Native POSIX Thread Library (NPTL)
5040 GDB's thread code has been updated to work with either the new
5041 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5043 * Separate debug info.
5045 GDB, in conjunction with BINUTILS, now supports a mechanism for
5046 automatically loading debug information from a separate file. Instead
5047 of shipping full debug and non-debug versions of system libraries,
5048 system integrators can now instead ship just the stripped libraries
5049 and optional debug files.
5051 * DWARF 2 Location Expressions
5053 DWARF 2 Location Expressions allow the compiler to more completely
5054 describe the location of variables (even in optimized code) to the
5057 GDB now includes preliminary support for location expressions (support
5058 for DW_OP_piece is still missing).
5062 A number of long standing bugs that caused GDB to die while starting a
5063 Java application have been fixed. GDB's Java support is now
5064 considered "useable".
5066 * GNU/Linux support for fork, vfork, and exec.
5068 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5069 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5072 * GDB supports logging output to a file
5074 There are two new commands, "set logging" and "show logging", which can be
5075 used to capture GDB's output to a file.
5077 * The meaning of "detach" has changed for gdbserver
5079 The "detach" command will now resume the application, as documented. To
5080 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5083 * d10v, m68hc11 `regs' command deprecated
5085 The `info registers' command has been updated so that it displays the
5086 registers using a format identical to the old `regs' command.
5090 A new command, "maint set profile on/off", has been added. This command can
5091 be used to enable or disable profiling while running GDB, to profile a
5092 session or a set of commands. In addition there is a new configure switch,
5093 "--enable-profiling", which will cause GDB to be compiled with profiling
5094 data, for more informative profiling results.
5096 * Default MI syntax changed to "mi2".
5098 The default MI (machine interface) syntax, enabled by the command line
5099 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5100 "mi1", can be enabled by specifying the option "-i=mi1".
5102 Support for the original "mi0" syntax (included in GDB 5.0) has been
5105 Fix for gdb/192: removed extraneous space when displaying frame level.
5106 Fix for gdb/672: update changelist is now output in mi list format.
5107 Fix for gdb/702: a -var-assign that updates the value now shows up
5108 in a subsequent -var-update.
5110 * New native configurations.
5112 FreeBSD/amd64 x86_64-*-freebsd*
5114 * Multi-arched targets.
5116 HP/PA HPUX11 hppa*-*-hpux*
5117 Renesas M32R/D w/simulator m32r-*-elf*
5119 * OBSOLETE configurations and files
5121 Configurations that have been declared obsolete in this release have
5122 been commented out. Unless there is activity to revive these
5123 configurations, the next release of GDB will have their sources
5124 permanently REMOVED.
5126 Z8000 simulator z8k-zilog-none or z8ksim
5127 Matsushita MN10200 w/simulator mn10200-*-*
5128 H8/500 simulator h8500-hitachi-hms or h8500hms
5129 HP/PA running BSD hppa*-*-bsd*
5130 HP/PA running OSF/1 hppa*-*-osf*
5131 HP/PA Pro target hppa*-*-pro*
5132 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5133 Sequent family i[3456]86-sequent-sysv4*
5134 i[3456]86-sequent-sysv*
5135 i[3456]86-sequent-bsd*
5136 Tsqware Sparclet sparclet-*-*
5137 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5139 * REMOVED configurations and files
5142 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5143 IBM AIX PS/2 i[3456]86-*-aix
5144 i386 running Mach 3.0 i[3456]86-*-mach3*
5145 i386 running Mach i[3456]86-*-mach*
5146 i386 running OSF/1 i[3456]86-*osf1mk*
5147 HP/Apollo 68k Family m68*-apollo*-sysv*,
5149 m68*-hp-bsd*, m68*-hp-hpux*
5150 Argonaut Risc Chip (ARC) arc-*-*
5151 Mitsubishi D30V d30v-*-*
5152 Fujitsu FR30 fr30-*-elf*
5153 OS/9000 i[34]86-*-os9k
5154 I960 with MON960 i960-*-coff
5156 * MIPS $fp behavior changed
5158 The convenience variable $fp, for the MIPS, now consistently returns
5159 the address of the current frame's base. Previously, depending on the
5160 context, $fp could refer to either $sp or the current frame's base
5161 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5162 The GNU Source-Level Debugger''.
5164 *** Changes in GDB 5.3:
5166 * GNU/Linux shared library multi-threaded performance improved.
5168 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5169 `/proc', in preference to `ptrace' for memory reads. This may result
5170 in an improvement in the start-up time of multi-threaded, shared
5171 library applications when run under GDB. One GDB user writes: ``loads
5172 shared libs like mad''.
5174 * ``gdbserver'' now supports multi-threaded applications on some targets
5176 Support for debugging multi-threaded applications which use
5177 the GNU/Linux LinuxThreads package has been added for
5178 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5179 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5181 * GDB now supports C/C++ preprocessor macros.
5183 GDB now expands preprocessor macro invocations in C/C++ expressions,
5184 and provides various commands for showing macro definitions and how
5187 The new command `macro expand EXPRESSION' expands any macro
5188 invocations in expression, and shows the result.
5190 The new command `show macro MACRO-NAME' shows the definition of the
5191 macro named MACRO-NAME, and where it was defined.
5193 Most compilers don't include information about macros in the debugging
5194 information by default. In GCC 3.1, for example, you need to compile
5195 your program with the options `-gdwarf-2 -g3'. If the macro
5196 information is present in the executable, GDB will read it.
5198 * Multi-arched targets.
5200 DEC Alpha (partial) alpha*-*-*
5201 DEC VAX (partial) vax-*-*
5203 National Semiconductor NS32000 (partial) ns32k-*-*
5204 Motorola 68000 (partial) m68k-*-*
5205 Motorola MCORE mcore-*-*
5209 Fujitsu FRV architecture added by Red Hat frv*-*-*
5212 * New native configurations
5214 Alpha NetBSD alpha*-*-netbsd*
5215 SH NetBSD sh*-*-netbsdelf*
5216 MIPS NetBSD mips*-*-netbsd*
5217 UltraSPARC NetBSD sparc64-*-netbsd*
5219 * OBSOLETE configurations and files
5221 Configurations that have been declared obsolete in this release have
5222 been commented out. Unless there is activity to revive these
5223 configurations, the next release of GDB will have their sources
5224 permanently REMOVED.
5226 Mitsubishi D30V d30v-*-*
5227 OS/9000 i[34]86-*-os9k
5228 IBM AIX PS/2 i[3456]86-*-aix
5229 Fujitsu FR30 fr30-*-elf*
5230 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5231 Argonaut Risc Chip (ARC) arc-*-*
5232 i386 running Mach 3.0 i[3456]86-*-mach3*
5233 i386 running Mach i[3456]86-*-mach*
5234 i386 running OSF/1 i[3456]86-*osf1mk*
5235 HP/Apollo 68k Family m68*-apollo*-sysv*,
5237 m68*-hp-bsd*, m68*-hp-hpux*
5238 I960 with MON960 i960-*-coff
5240 * OBSOLETE languages
5242 CHILL, a Pascal like language used by telecommunications companies.
5244 * REMOVED configurations and files
5246 AMD 29k family via UDI a29k-amd-udi, udi29k
5247 A29K VxWorks a29k-*-vxworks
5248 AMD 29000 embedded, using EBMON a29k-none-none
5249 AMD 29000 embedded with COFF a29k-none-coff
5250 AMD 29000 embedded with a.out a29k-none-aout
5252 testsuite/gdb.hp/gdb.threads-hp/ directory
5254 * New command "set max-user-call-depth <nnn>"
5256 This command allows the user to limit the call depth of user-defined
5257 commands. The default is 1024.
5259 * Changes in FreeBSD/i386 native debugging.
5261 Support for the "generate-core-file" has been added.
5263 * New commands "dump", "append", and "restore".
5265 These commands allow data to be copied from target memory
5266 to a bfd-format or binary file (dump and append), and back
5267 from a file into memory (restore).
5269 * Improved "next/step" support on multi-processor Alpha Tru64.
5271 The previous single-step mechanism could cause unpredictable problems,
5272 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5273 of a software single-step mechanism prevents this.
5275 *** Changes in GDB 5.2.1:
5283 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5284 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5285 Fix, by Joel Brobecker imported from mainline.
5287 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5288 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5289 Fix, by Fred Fish, imported from mainline.
5291 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5292 Surprisingly enough, it works now.
5293 By Michal Ludvig, imported from mainline.
5295 i386 hardware watchpoint support:
5296 avoid misses on second run for some targets.
5297 By Pierre Muller, imported from mainline.
5299 *** Changes in GDB 5.2:
5301 * New command "set trust-readonly-sections on[off]".
5303 This command is a hint that tells gdb that read-only sections
5304 really are read-only (ie. that their contents will not change).
5305 In this mode, gdb will go to the object file rather than the
5306 target to read memory from read-only sections (such as ".text").
5307 This can be a significant performance improvement on some
5308 (notably embedded) targets.
5310 * New command "generate-core-file" (or "gcore").
5312 This new gdb command allows the user to drop a core file of the child
5313 process state at any time. So far it's been implemented only for
5314 GNU/Linux and Solaris, but should be relatively easily ported to other
5315 hosts. Argument is core file name (defaults to core.<pid>).
5317 * New command line option
5319 GDB now accepts --pid or -p followed by a process id.
5321 * Change in command line behavior -- corefiles vs. process ids.
5323 There is a subtle behavior in the way in which GDB handles
5324 command line arguments. The first non-flag argument is always
5325 a program to debug, but the second non-flag argument may either
5326 be a corefile or a process id. Previously, GDB would attempt to
5327 open the second argument as a corefile, and if that failed, would
5328 issue a superfluous error message and then attempt to attach it as
5329 a process. Now, if the second argument begins with a non-digit,
5330 it will be treated as a corefile. If it begins with a digit,
5331 GDB will attempt to attach it as a process, and if no such process
5332 is found, will then attempt to open it as a corefile.
5334 * Changes in ARM configurations.
5336 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5337 configuration is fully multi-arch.
5339 * New native configurations
5341 ARM NetBSD arm*-*-netbsd*
5342 x86 OpenBSD i[3456]86-*-openbsd*
5343 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5344 Sparc64 running FreeBSD sparc64-*-freebsd*
5348 Sanyo XStormy16 xstormy16-elf
5350 * OBSOLETE configurations and files
5352 Configurations that have been declared obsolete in this release have
5353 been commented out. Unless there is activity to revive these
5354 configurations, the next release of GDB will have their sources
5355 permanently REMOVED.
5357 AMD 29k family via UDI a29k-amd-udi, udi29k
5358 A29K VxWorks a29k-*-vxworks
5359 AMD 29000 embedded, using EBMON a29k-none-none
5360 AMD 29000 embedded with COFF a29k-none-coff
5361 AMD 29000 embedded with a.out a29k-none-aout
5363 testsuite/gdb.hp/gdb.threads-hp/ directory
5365 * REMOVED configurations and files
5367 TI TMS320C80 tic80-*-*
5369 PowerPC Solaris powerpcle-*-solaris*
5370 PowerPC Windows NT powerpcle-*-cygwin32
5371 PowerPC Netware powerpc-*-netware*
5372 Harris/CXUX m88k m88*-harris-cxux*
5373 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5374 ns32k-utek-sysv* ns32k-utek-*
5375 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5376 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5377 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5378 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5379 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5381 * Changes to command line processing
5383 The new `--args' feature can be used to specify command-line arguments
5384 for the inferior from gdb's command line.
5386 * Changes to key bindings
5388 There is a new `operate-and-get-next' function bound to `C-o'.
5390 *** Changes in GDB 5.1.1
5392 Fix compile problem on DJGPP.
5394 Fix a problem with floating-point registers on the i386 being
5397 Fix to stop GDB crashing on .debug_str debug info.
5399 Numerous documentation fixes.
5401 Numerous testsuite fixes.
5403 *** Changes in GDB 5.1:
5405 * New native configurations
5407 Alpha FreeBSD alpha*-*-freebsd*
5408 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5409 MIPS GNU/Linux mips*-*-linux*
5410 MIPS SGI Irix 6.x mips*-sgi-irix6*
5411 ia64 AIX ia64-*-aix*
5412 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5416 Motorola 68HC11 and 68HC12 m68hc11-elf
5418 UltraSparc running GNU/Linux sparc64-*-linux*
5420 * OBSOLETE configurations and files
5422 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5423 Harris/CXUX m88k m88*-harris-cxux*
5424 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5425 ns32k-utek-sysv* ns32k-utek-*
5426 TI TMS320C80 tic80-*-*
5428 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5429 PowerPC Solaris powerpcle-*-solaris*
5430 PowerPC Windows NT powerpcle-*-cygwin32
5431 PowerPC Netware powerpc-*-netware*
5432 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5433 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5434 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5435 Apple Macintosh (MPW) host N/A
5437 stuff.c (Program to stuff files into a specially prepared space in kdb)
5438 kdb-start.c (Main loop for the standalone kernel debugger)
5440 Configurations that have been declared obsolete in this release have
5441 been commented out. Unless there is activity to revive these
5442 configurations, the next release of GDB will have their sources
5443 permanently REMOVED.
5445 * REMOVED configurations and files
5447 Altos 3068 m68*-altos-*
5448 Convex c1-*-*, c2-*-*
5450 ARM RISCix arm-*-* (as host)
5454 * GDB has been converted to ISO C.
5456 GDB's source code has been converted to ISO C. In particular, the
5457 sources are fully protoized, and rely on standard headers being
5462 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5464 * The MI enabled by default.
5466 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5467 revised and enabled by default. Packages which use GDB as a debugging
5468 engine behind a UI or another front end are encouraged to switch to
5469 using the GDB/MI interface, instead of the old annotations interface
5470 which is now deprecated.
5472 * Support for debugging Pascal programs.
5474 GDB now includes support for debugging Pascal programs. The following
5475 main features are supported:
5477 - Pascal-specific data types such as sets;
5479 - automatic recognition of Pascal sources based on file-name
5482 - Pascal-style display of data types, variables, and functions;
5484 - a Pascal expression parser.
5486 However, some important features are not yet supported.
5488 - Pascal string operations are not supported at all;
5490 - there are some problems with boolean types;
5492 - Pascal type hexadecimal constants are not supported
5493 because they conflict with the internal variables format;
5495 - support for Pascal objects and classes is not full yet;
5497 - unlike Pascal, GDB is case-sensitive for symbol names.
5499 * Changes in completion.
5501 Commands such as `shell', `run' and `set args', which pass arguments
5502 to inferior programs, now complete on file names, similar to what
5503 users expect at the shell prompt.
5505 Commands which accept locations, such as `disassemble', `print',
5506 `breakpoint', `until', etc. now complete on filenames as well as
5507 program symbols. Thus, if you type "break foob TAB", and the source
5508 files linked into the programs include `foobar.c', that file name will
5509 be one of the candidates for completion. However, file names are not
5510 considered for completion after you typed a colon that delimits a file
5511 name from a name of a function in that file, as in "break foo.c:bar".
5513 `set demangle-style' completes on available demangling styles.
5515 * New platform-independent commands:
5517 It is now possible to define a post-hook for a command as well as a
5518 hook that runs before the command. For more details, see the
5519 documentation of `hookpost' in the GDB manual.
5521 * Changes in GNU/Linux native debugging.
5523 Support for debugging multi-threaded programs has been completely
5524 revised for all platforms except m68k and sparc. You can now debug as
5525 many threads as your system allows you to have.
5527 Attach/detach is supported for multi-threaded programs.
5529 Support for SSE registers was added for x86. This doesn't work for
5530 multi-threaded programs though.
5532 * Changes in MIPS configurations.
5534 Multi-arch support is enabled for all MIPS configurations.
5536 GDB can now be built as native debugger on SGI Irix 6.x systems for
5537 debugging n32 executables. (Debugging 64-bit executables is not yet
5540 * Unified support for hardware watchpoints in all x86 configurations.
5542 Most (if not all) native x86 configurations support hardware-assisted
5543 breakpoints and watchpoints in a unified manner. This support
5544 implements debug register sharing between watchpoints, which allows to
5545 put a virtually infinite number of watchpoints on the same address,
5546 and also supports watching regions up to 16 bytes with several debug
5549 The new maintenance command `maintenance show-debug-regs' toggles
5550 debugging print-outs in functions that insert, remove, and test
5551 watchpoints and hardware breakpoints.
5553 * Changes in the DJGPP native configuration.
5555 New command ``info dos sysinfo'' displays assorted information about
5556 the CPU, OS, memory, and DPMI server.
5558 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5559 display information about segment descriptors stored in GDT, LDT, and
5562 New commands ``info dos pde'' and ``info dos pte'' display entries
5563 from Page Directory and Page Tables (for now works with CWSDPMI only).
5564 New command ``info dos address-pte'' displays the Page Table entry for
5565 a given linear address.
5567 GDB can now pass command lines longer than 126 characters to the
5568 program being debugged (requires an update to the libdbg.a library
5569 which is part of the DJGPP development kit).
5571 DWARF2 debug info is now supported.
5573 It is now possible to `step' and `next' through calls to `longjmp'.
5575 * Changes in documentation.
5577 All GDB documentation was converted to GFDL, the GNU Free
5578 Documentation License.
5580 Tracepoints-related commands are now fully documented in the GDB
5583 TUI, the Text-mode User Interface, is now documented in the manual.
5585 Tracepoints-related commands are now fully documented in the GDB
5588 The "GDB Internals" manual now has an index. It also includes
5589 documentation of `ui_out' functions, GDB coding standards, x86
5590 hardware watchpoints, and memory region attributes.
5592 * GDB's version number moved to ``version.in''
5594 The Makefile variable VERSION has been replaced by the file
5595 ``version.in''. People creating GDB distributions should update the
5596 contents of this file.
5600 GUD support is now a standard part of the EMACS distribution.
5602 *** Changes in GDB 5.0:
5604 * Improved support for debugging FP programs on x86 targets
5606 Unified and much-improved support for debugging floating-point
5607 programs on all x86 targets. In particular, ``info float'' now
5608 displays the FP registers in the same format on all x86 targets, with
5609 greater level of detail.
5611 * Improvements and bugfixes in hardware-assisted watchpoints
5613 It is now possible to watch array elements, struct members, and
5614 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5615 on x86 targets no longer erroneously trigger when the address is
5618 * Improvements in the native DJGPP version of GDB
5620 The distribution now includes all the scripts and auxiliary files
5621 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5622 machines ``out of the box''.
5624 The DJGPP version can now debug programs that use signals. It is
5625 possible to catch signals that happened in the debuggee, deliver
5626 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5627 would kill the program being debugged.) Programs that hook hardware
5628 interrupts (keyboard, timer, etc.) can also be debugged.
5630 It is now possible to debug DJGPP programs that redirect their
5631 standard handles or switch them to raw (as opposed to cooked) mode, or
5632 even close them. The command ``run < foo > bar'' works as expected,
5633 and ``info terminal'' reports useful information about the debuggee's
5634 terminal, including raw/cooked mode, redirection, etc.
5636 The DJGPP version now uses termios functions for console I/O, which
5637 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5640 DOS-style file names with drive letters are now fully supported by
5643 It is now possible to debug DJGPP programs that switch their working
5644 directory. It is also possible to rerun the debuggee any number of
5645 times without restarting GDB; thus, you can use the same setup,
5646 breakpoints, etc. for many debugging sessions.
5648 * New native configurations
5650 ARM GNU/Linux arm*-*-linux*
5651 PowerPC GNU/Linux powerpc-*-linux*
5655 Motorola MCore mcore-*-*
5656 x86 VxWorks i[3456]86-*-vxworks*
5657 PowerPC VxWorks powerpc-*-vxworks*
5658 TI TMS320C80 tic80-*-*
5660 * OBSOLETE configurations
5662 Altos 3068 m68*-altos-*
5663 Convex c1-*-*, c2-*-*
5665 ARM RISCix arm-*-* (as host)
5668 Configurations that have been declared obsolete will be commented out,
5669 but the code will be left in place. If there is no activity to revive
5670 these configurations before the next release of GDB, the sources will
5671 be permanently REMOVED.
5673 * Gould support removed
5675 Support for the Gould PowerNode and NP1 has been removed.
5677 * New features for SVR4
5679 On SVR4 native platforms (such as Solaris), if you attach to a process
5680 without first loading a symbol file, GDB will now attempt to locate and
5681 load symbols from the running process's executable file.
5683 * Many C++ enhancements
5685 C++ support has been greatly improved. Overload resolution now works properly
5686 in almost all cases. RTTI support is on the way.
5688 * Remote targets can connect to a sub-program
5690 A popen(3) style serial-device has been added. This device starts a
5691 sub-process (such as a stand-alone simulator) and then communicates
5692 with that. The sub-program to run is specified using the syntax
5693 ``|<program> <args>'' vis:
5695 (gdb) set remotedebug 1
5696 (gdb) target extended-remote |mn10300-elf-sim program-args
5698 * MIPS 64 remote protocol
5700 A long standing bug in the mips64 remote protocol where by GDB
5701 expected certain 32 bit registers (ex SR) to be transfered as 32
5702 instead of 64 bits has been fixed.
5704 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5705 added to provide backward compatibility with older versions of GDB.
5707 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5709 The command ``set remotebinarydownload'' command has been replaced by
5710 ``set remote X-packet''. Other commands in ``set remote'' family
5711 include ``set remote P-packet''.
5713 * Breakpoint commands accept ranges.
5715 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5716 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5717 ``tracepoint passcount'' also accepts a range of tracepoints.
5719 * ``apropos'' command added.
5721 The ``apropos'' command searches through command names and
5722 documentation strings, printing out matches, making it much easier to
5723 try to find a command that does what you are looking for.
5727 A new machine oriented interface (MI) has been added to GDB. This
5728 interface is designed for debug environments running GDB as a separate
5729 process. This is part of the long term libGDB project. See the
5730 "GDB/MI" chapter of the GDB manual for further information. It can be
5731 enabled by configuring with:
5733 .../configure --enable-gdbmi
5735 *** Changes in GDB-4.18:
5737 * New native configurations
5739 HP-UX 10.20 hppa*-*-hpux10.20
5740 HP-UX 11.x hppa*-*-hpux11.0*
5741 M68K GNU/Linux m68*-*-linux*
5745 Fujitsu FR30 fr30-*-elf*
5746 Intel StrongARM strongarm-*-*
5747 Mitsubishi D30V d30v-*-*
5749 * OBSOLETE configurations
5751 Gould PowerNode, NP1 np1-*-*, pn-*-*
5753 Configurations that have been declared obsolete will be commented out,
5754 but the code will be left in place. If there is no activity to revive
5755 these configurations before the next release of GDB, the sources will
5756 be permanently REMOVED.
5760 As a compatibility experiment, GDB's source files buildsym.h and
5761 buildsym.c have been converted to pure standard C, no longer
5762 containing any K&R compatibility code. We believe that all systems in
5763 use today either come with a standard C compiler, or have a GCC port
5764 available. If this is not true, please report the affected
5765 configuration to bug-gdb@gnu.org immediately. See the README file for
5766 information about getting a standard C compiler if you don't have one
5771 GDB now uses readline 2.2.
5773 * set extension-language
5775 You can now control the mapping between filename extensions and source
5776 languages by using the `set extension-language' command. For instance,
5777 you can ask GDB to treat .c files as C++ by saying
5778 set extension-language .c c++
5779 The command `info extensions' lists all of the recognized extensions
5780 and their associated languages.
5782 * Setting processor type for PowerPC and RS/6000
5784 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5785 you can use the `set processor' command to specify what variant of the
5786 PowerPC family you are debugging. The command
5790 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5791 following PowerPC and RS6000 variants:
5793 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5794 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5796 403GC IBM PowerPC 403GC
5797 505 Motorola PowerPC 505
5798 860 Motorola PowerPC 860 or 850
5799 601 Motorola PowerPC 601
5800 602 Motorola PowerPC 602
5801 603 Motorola/IBM PowerPC 603 or 603e
5802 604 Motorola PowerPC 604 or 604e
5803 750 Motorola/IBM PowerPC 750 or 750
5805 At the moment, this command just tells GDB what to name the
5806 special-purpose processor registers. Since almost all the affected
5807 registers are inaccessible to user-level programs, this command is
5808 only useful for remote debugging in its present form.
5812 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5813 more extensive support for HP-UX. Added features include shared
5814 library support, kernel threads and hardware watchpoints for 11.00,
5815 support for HP's ANSI C and C++ compilers, and a compatibility mode
5816 for xdb and dbx commands.
5820 HP's donation includes the new concept of catchpoints, which is a
5821 generalization of the old catch command. On HP-UX, it is now possible
5822 to catch exec, fork, and vfork, as well as library loading.
5824 This means that the existing catch command has changed; its first
5825 argument now specifies the type of catch to be set up. See the
5826 output of "help catch" for a list of catchpoint types.
5828 * Debugging across forks
5830 On HP-UX, you can choose which process to debug when a fork() happens
5835 HP has donated a curses-based terminal user interface (TUI). To get
5836 it, build with --enable-tui. Although this can be enabled for any
5837 configuration, at present it only works for native HP debugging.
5839 * GDB remote protocol additions
5841 A new protocol packet 'X' that writes binary data is now available.
5842 Default behavior is to try 'X', then drop back to 'M' if the stub
5843 fails to respond. The settable variable `remotebinarydownload'
5844 allows explicit control over the use of 'X'.
5846 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5847 full 64-bit address. The command
5849 set remoteaddresssize 32
5851 can be used to revert to the old behaviour. For existing remote stubs
5852 the change should not be noticed, as the additional address information
5855 In order to assist in debugging stubs, you may use the maintenance
5856 command `packet' to send any text string to the stub. For instance,
5858 maint packet heythere
5860 sends the packet "$heythere#<checksum>". Note that it is very easy to
5861 disrupt a debugging session by sending the wrong packet at the wrong
5864 The compare-sections command allows you to compare section data on the
5865 target to what is in the executable file without uploading or
5866 downloading, by comparing CRC checksums.
5868 * Tracing can collect general expressions
5870 You may now collect general expressions at tracepoints. This requires
5871 further additions to the target-side stub; see tracepoint.c and
5872 doc/agentexpr.texi for further details.
5874 * mask-address variable for Mips
5876 For Mips targets, you may control the zeroing of the upper 32 bits of
5877 a 64-bit address by entering `set mask-address on'. This is mainly
5878 of interest to users of embedded R4xxx and R5xxx processors.
5880 * Higher serial baud rates
5882 GDB's serial code now allows you to specify baud rates 57600, 115200,
5883 230400, and 460800 baud. (Note that your host system may not be able
5884 to achieve all of these rates.)
5888 The i960 configuration now includes an initial implementation of a
5889 builtin simulator, contributed by Jim Wilson.
5892 *** Changes in GDB-4.17:
5894 * New native configurations
5896 Alpha GNU/Linux alpha*-*-linux*
5897 Unixware 2.x i[3456]86-unixware2*
5898 Irix 6.x mips*-sgi-irix6*
5899 PowerPC GNU/Linux powerpc-*-linux*
5900 PowerPC Solaris powerpcle-*-solaris*
5901 Sparc GNU/Linux sparc-*-linux*
5902 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5906 Argonaut Risc Chip (ARC) arc-*-*
5907 Hitachi H8/300S h8300*-*-*
5908 Matsushita MN10200 w/simulator mn10200-*-*
5909 Matsushita MN10300 w/simulator mn10300-*-*
5910 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5911 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5912 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5913 Mitsubishi D10V w/simulator d10v-*-*
5914 Mitsubishi M32R/D w/simulator m32r-*-elf*
5915 Tsqware Sparclet sparclet-*-*
5916 NEC V850 w/simulator v850-*-*
5918 * New debugging protocols
5920 ARM with RDI protocol arm*-*-*
5921 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5922 DDB and LSI variants of PMON protocol mips*-*-*
5923 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5924 PowerPC with SDS protocol powerpc{,le}-*-eabi
5925 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5929 All configurations can now understand and use the DWARF 2 debugging
5930 format. The choice is automatic, if the symbol file contains DWARF 2
5935 GDB now includes basic Java language support. This support is
5936 only useful with Java compilers that produce native machine code.
5938 * solib-absolute-prefix and solib-search-path
5940 For SunOS and SVR4 shared libraries, you may now set the prefix for
5941 loading absolute shared library symbol files, and the search path for
5942 locating non-absolute shared library symbol files.
5944 * Live range splitting
5946 GDB can now effectively debug code for which GCC has performed live
5947 range splitting as part of its optimization. See gdb/doc/LRS for
5948 more details on the expected format of the stabs information.
5952 GDB's support for the GNU Hurd, including thread debugging, has been
5953 updated to work with current versions of the Hurd.
5957 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5958 instruction set. ARM GDB automatically detects when Thumb
5959 instructions are in use, and adjusts disassembly and backtracing
5964 GDB's MIPS target configurations now handle the MIP16 16-bit
5969 GDB now includes support for overlays; if an executable has been
5970 linked such that multiple sections are based at the same address, GDB
5971 will decide which section to use for symbolic info. You can choose to
5972 control the decision manually, using overlay commands, or implement
5973 additional target-side support and use "overlay load-target" to bring
5974 in the overlay mapping. Do "help overlay" for more detail.
5978 The command "info symbol <address>" displays information about
5979 the symbol at the specified address.
5983 The standard remote protocol now includes an extension that allows
5984 asynchronous collection and display of trace data. This requires
5985 extensive support in the target-side debugging stub. Tracing mode
5986 includes a new interaction mode in GDB and new commands: see the
5987 file tracepoint.c for more details.
5991 Configurations for embedded MIPS now include a simulator contributed
5992 by Cygnus Solutions. The simulator supports the instruction sets
5993 of most MIPS variants.
5997 Sparc configurations may now include the ERC32 simulator contributed
5998 by the European Space Agency. The simulator is not built into
5999 Sparc targets by default; configure with --enable-sim to include it.
6003 For target configurations that may include multiple variants of a
6004 basic architecture (such as MIPS and SH), you may now set the
6005 architecture explicitly. "set arch" sets, "info arch" lists
6006 the possible architectures.
6008 *** Changes in GDB-4.16:
6010 * New native configurations
6012 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6013 M68K NetBSD m68k-*-netbsd*
6014 PowerPC AIX 4.x powerpc-*-aix*
6015 PowerPC MacOS powerpc-*-macos*
6016 PowerPC Windows NT powerpcle-*-cygwin32
6017 RS/6000 AIX 4.x rs6000-*-aix4*
6021 ARM with RDP protocol arm-*-*
6022 I960 with MON960 i960-*-coff
6023 MIPS VxWorks mips*-*-vxworks*
6024 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6025 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6027 Matra Sparclet sparclet-*-*
6031 The powerpc-eabi configuration now includes the PSIM simulator,
6032 contributed by Andrew Cagney, with assistance from Mike Meissner.
6033 PSIM is a very elaborate model of the PowerPC, including not only
6034 basic instruction set execution, but also details of execution unit
6035 performance and I/O hardware. See sim/ppc/README for more details.
6039 GDB now works with Solaris 2.5.
6041 * Windows 95/NT native
6043 GDB will now work as a native debugger on Windows 95 and Windows NT.
6044 To build it from source, you must use the "gnu-win32" environment,
6045 which uses a DLL to emulate enough of Unix to run the GNU tools.
6046 Further information, binaries, and sources are available at
6047 ftp.cygnus.com, under pub/gnu-win32.
6049 * dont-repeat command
6051 If a user-defined command includes the command `dont-repeat', then the
6052 command will not be repeated if the user just types return. This is
6053 useful if the command is time-consuming to run, so that accidental
6054 extra keystrokes don't run the same command many times.
6056 * Send break instead of ^C
6058 The standard remote protocol now includes an option to send a break
6059 rather than a ^C to the target in order to interrupt it. By default,
6060 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6062 * Remote protocol timeout
6064 The standard remote protocol includes a new variable `remotetimeout'
6065 that allows you to set the number of seconds before GDB gives up trying
6066 to read from the target. The default value is 2.
6068 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6070 By default GDB will automatically keep track of objects as they are
6071 loaded and unloaded by the dynamic linker. By using the command `set
6072 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6073 when shared library events occur, thus allowing you to set breakpoints
6074 in shared libraries which are explicitly loaded by the inferior.
6076 Note this feature does not work on hpux8. On hpux9 you must link
6077 /usr/lib/end.o into your program. This feature should work
6078 automatically on hpux10.
6080 * Irix 5.x hardware watchpoint support
6082 Irix 5 configurations now support the use of hardware watchpoints.
6084 * Mips protocol "SYN garbage limit"
6086 When debugging a Mips target using the `target mips' protocol, you
6087 may set the number of characters that GDB will ignore by setting
6088 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6089 every character. The default value is 1050.
6091 * Recording and replaying remote debug sessions
6093 If you set `remotelogfile' to the name of a file, gdb will write to it
6094 a recording of a remote debug session. This recording may then be
6095 replayed back to gdb using "gdbreplay". See gdbserver/README for
6096 details. This is useful when you have a problem with GDB while doing
6097 remote debugging; you can make a recording of the session and send it
6098 to someone else, who can then recreate the problem.
6100 * Speedups for remote debugging
6102 GDB includes speedups for downloading and stepping MIPS systems using
6103 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6104 and more efficient S-record downloading.
6106 * Memory use reductions and statistics collection
6108 GDB now uses less memory and reports statistics about memory usage.
6109 Try the `maint print statistics' command, for example.
6111 *** Changes in GDB-4.15:
6113 * Psymtabs for XCOFF
6115 The symbol reader for AIX GDB now uses partial symbol tables. This
6116 can greatly improve startup time, especially for large executables.
6118 * Remote targets use caching
6120 Remote targets now use a data cache to speed up communication with the
6121 remote side. The data cache could lead to incorrect results because
6122 it doesn't know about volatile variables, thus making it impossible to
6123 debug targets which use memory mapped I/O devices. `set remotecache
6124 off' turns the the data cache off.
6126 * Remote targets may have threads
6128 The standard remote protocol now includes support for multiple threads
6129 in the target system, using new protocol commands 'H' and 'T'. See
6130 gdb/remote.c for details.
6134 If GDB is configured with `--enable-netrom', then it will include
6135 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6136 acts as though it is a bank of ROM on the target board, but you can
6137 write into it over the network. GDB's support consists only of
6138 support for fast loading into the emulated ROM; to debug, you must use
6139 another protocol, such as standard remote protocol. The usual
6140 sequence is something like
6142 target nrom <netrom-hostname>
6144 target remote <netrom-hostname>:1235
6148 GDB now includes support for the Apple Macintosh, as a host only. It
6149 may be run as either an MPW tool or as a standalone application, and
6150 it can debug through the serial port. All the usual GDB commands are
6151 available, but to the target command, you must supply "serial" as the
6152 device type instead of "/dev/ttyXX". See mpw-README in the main
6153 directory for more information on how to build. The MPW configuration
6154 scripts */mpw-config.in support only a few targets, and only the
6155 mips-idt-ecoff target has been tested.
6159 GDB configuration now uses autoconf. This is not user-visible,
6160 but does simplify configuration and building.
6164 GDB now supports hpux10.
6166 *** Changes in GDB-4.14:
6168 * New native configurations
6170 x86 FreeBSD i[345]86-*-freebsd
6171 x86 NetBSD i[345]86-*-netbsd
6172 NS32k NetBSD ns32k-*-netbsd
6173 Sparc NetBSD sparc-*-netbsd
6177 A29K VxWorks a29k-*-vxworks
6178 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6179 CPU32 EST-300 emulator m68*-*-est*
6180 PowerPC ELF powerpc-*-elf
6183 * Alpha OSF/1 support for procfs
6185 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6186 possible to attach to running processes. As the mounting of the /proc
6187 filesystem is optional on the Alpha, GDB automatically determines
6188 the availability of /proc during startup. This can lead to problems
6189 if /proc is unmounted after GDB has been started.
6191 * Arguments to user-defined commands
6193 User commands may accept up to 10 arguments separated by whitespace.
6194 Arguments are accessed within the user command via $arg0..$arg9. A
6197 print $arg0 + $arg1 + $arg2
6199 To execute the command use:
6202 Defines the command "adder" which prints the sum of its three arguments.
6203 Note the arguments are text substitutions, so they may reference variables,
6204 use complex expressions, or even perform inferior function calls.
6206 * New `if' and `while' commands
6208 This makes it possible to write more sophisticated user-defined
6209 commands. Both commands take a single argument, which is the
6210 expression to evaluate, and must be followed by the commands to
6211 execute, one per line, if the expression is nonzero, the list being
6212 terminated by the word `end'. The `if' command list may include an
6213 `else' word, which causes the following commands to be executed only
6214 if the expression is zero.
6216 * Fortran source language mode
6218 GDB now includes partial support for Fortran 77. It will recognize
6219 Fortran programs and can evaluate a subset of Fortran expressions, but
6220 variables and functions may not be handled correctly. GDB will work
6221 with G77, but does not yet know much about symbols emitted by other
6224 * Better HPUX support
6226 Most debugging facilities now work on dynamic executables for HPPAs
6227 running hpux9 or later. You can attach to running dynamically linked
6228 processes, but by default the dynamic libraries will be read-only, so
6229 for instance you won't be able to put breakpoints in them. To change
6230 that behavior do the following before running the program:
6236 This will cause the libraries to be mapped private and read-write.
6237 To revert to the normal behavior, do this:
6243 You cannot set breakpoints or examine data in the library until after
6244 the library is loaded if the function/data symbols do not have
6247 GDB can now also read debug symbols produced by the HP C compiler on
6248 HPPAs (sorry, no C++, Fortran or 68k support).
6250 * Target byte order now dynamically selectable
6252 You can choose which byte order to use with a target system, via the
6253 commands "set endian big" and "set endian little", and you can see the
6254 current setting by using "show endian". You can also give the command
6255 "set endian auto", in which case GDB will use the byte order
6256 associated with the executable. Currently, only embedded MIPS
6257 configurations support dynamic selection of target byte order.
6259 * New DOS host serial code
6261 This version uses DPMI interrupts to handle buffered I/O, so you
6262 no longer need to run asynctsr when debugging boards connected to
6265 *** Changes in GDB-4.13:
6267 * New "complete" command
6269 This lists all the possible completions for the rest of the line, if it
6270 were to be given as a command itself. This is intended for use by emacs.
6272 * Trailing space optional in prompt
6274 "set prompt" no longer adds a space for you after the prompt you set. This
6275 allows you to set a prompt which ends in a space or one that does not.
6277 * Breakpoint hit counts
6279 "info break" now displays a count of the number of times the breakpoint
6280 has been hit. This is especially useful in conjunction with "ignore"; you
6281 can ignore a large number of breakpoint hits, look at the breakpoint info
6282 to see how many times the breakpoint was hit, then run again, ignoring one
6283 less than that number, and this will get you quickly to the last hit of
6286 * Ability to stop printing at NULL character
6288 "set print null-stop" will cause GDB to stop printing the characters of
6289 an array when the first NULL is encountered. This is useful when large
6290 arrays actually contain only short strings.
6292 * Shared library breakpoints
6294 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6295 breakpoints in shared libraries before the executable is run.
6297 * Hardware watchpoints
6299 There is a new hardware breakpoint for the watch command for sparclite
6300 targets. See gdb/sparclite/hw_breakpoint.note.
6302 Hardware watchpoints are also now supported under GNU/Linux.
6306 Annotations have been added. These are for use with graphical interfaces,
6307 and are still experimental. Currently only gdba.el uses these.
6309 * Improved Irix 5 support
6311 GDB now works properly with Irix 5.2.
6313 * Improved HPPA support
6315 GDB now works properly with the latest GCC and GAS.
6317 * New native configurations
6319 Sequent PTX4 i[34]86-sequent-ptx4
6320 HPPA running OSF/1 hppa*-*-osf*
6321 Atari TT running SVR4 m68*-*-sysv4*
6322 RS/6000 LynxOS rs6000-*-lynxos*
6326 OS/9000 i[34]86-*-os9k
6327 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6330 * Hitachi SH7000 and E7000-PC ICE support
6332 There is now support for communicating with the Hitachi E7000-PC ICE.
6333 This is available automatically when GDB is configured for the SH.
6337 As usual, a variety of small fixes and improvements, both generic
6338 and configuration-specific. See the ChangeLog for more detail.
6340 *** Changes in GDB-4.12:
6342 * Irix 5 is now supported
6346 GDB-4.12 on the HPPA has a number of changes which make it unable
6347 to debug the output from the currently released versions of GCC and
6348 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6349 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6350 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6353 *** Changes in GDB-4.11:
6355 * User visible changes:
6359 The "set remotedebug" option is now consistent between the mips remote
6360 target, remote targets using the gdb-specific protocol, UDI (AMD's
6361 debug protocol for the 29k) and the 88k bug monitor. It is now an
6362 integer specifying a debug level (normally 0 or 1, but 2 means more
6363 debugging info for the mips target).
6365 * DEC Alpha native support
6367 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6368 debug info, but GDB works fairly well with the DEC compiler and should
6369 work with a future GCC release. See the README file for a few
6370 Alpha-specific notes.
6372 * Preliminary thread implementation
6374 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6376 * LynxOS native and target support for 386
6378 This release has been hosted on LynxOS 2.2, and also can be configured
6379 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6382 * Improvements in C++ mangling/demangling.
6384 This release has much better g++ debugging, specifically in name
6385 mangling/demangling, virtual function calls, print virtual table,
6386 call methods, ...etc.
6388 *** Changes in GDB-4.10:
6390 * User visible changes:
6392 Remote debugging using the GDB-specific (`target remote') protocol now
6393 supports the `load' command. This is only useful if you have some
6394 other way of getting the stub to the target system, and you can put it
6395 somewhere in memory where it won't get clobbered by the download.
6397 Filename completion now works.
6399 When run under emacs mode, the "info line" command now causes the
6400 arrow to point to the line specified. Also, "info line" prints
6401 addresses in symbolic form (as well as hex).
6403 All vxworks based targets now support a user settable option, called
6404 vxworks-timeout. This option represents the number of seconds gdb
6405 should wait for responses to rpc's. You might want to use this if
6406 your vxworks target is, perhaps, a slow software simulator or happens
6407 to be on the far side of a thin network line.
6411 This release contains support for using a DEC alpha as a GDB host for
6412 cross debugging. Native alpha debugging is not supported yet.
6415 *** Changes in GDB-4.9:
6419 This is the first GDB release which is accompanied by a matching testsuite.
6420 The testsuite requires installation of dejagnu, which should be available
6421 via ftp from most sites that carry GNU software.
6425 'Cfront' style demangling has had its name changed to 'ARM' style, to
6426 emphasize that it was written from the specifications in the C++ Annotated
6427 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6428 disclaimers, it still generated too much confusion with users attempting to
6429 use gdb with AT&T cfront.
6433 GDB now uses a standard remote interface to a simulator library.
6434 So far, the library contains simulators for the Zilog Z8001/2, the
6435 Hitachi H8/300, H8/500 and Super-H.
6437 * New targets supported
6439 H8/300 simulator h8300-hitachi-hms or h8300hms
6440 H8/500 simulator h8500-hitachi-hms or h8500hms
6441 SH simulator sh-hitachi-hms or sh
6442 Z8000 simulator z8k-zilog-none or z8ksim
6443 IDT MIPS board over serial line mips-idt-ecoff
6445 Cross-debugging to GO32 targets is supported. It requires a custom
6446 version of the i386-stub.c module which is integrated with the
6447 GO32 memory extender.
6449 * New remote protocols
6451 MIPS remote debugging protocol.
6453 * New source languages supported
6455 This version includes preliminary support for Chill, a Pascal like language
6456 used by telecommunications companies. Chill support is also being integrated
6457 into the GNU compiler, but we don't know when it will be publically available.
6460 *** Changes in GDB-4.8:
6462 * HP Precision Architecture supported
6464 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6465 version of this support was available as a set of patches from the
6466 University of Utah. GDB does not support debugging of programs
6467 compiled with the HP compiler, because HP will not document their file
6468 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6469 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6471 Many problems in the preliminary version have been fixed.
6473 * Faster and better demangling
6475 We have improved template demangling and fixed numerous bugs in the GNU style
6476 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6477 character types (wchar_t) are now supported. Demangling of each symbol is now
6478 only done once, and is cached when the symbol table for a file is read in.
6479 This results in a small increase in memory usage for C programs, a moderate
6480 increase in memory usage for C++ programs, and a fantastic speedup in
6483 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6484 from the specifications in the Annotated Reference Manual, which AT&T's
6485 compiler does not actually implement.
6487 * G++ multiple inheritance compiler problem
6489 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6490 inheritance lattices was reworked to properly discover ambiguities. We
6491 recently found an example which causes this new algorithm to fail in a
6492 very subtle way, producing bad debug information for those classes.
6493 The file 'gcc.patch' (in this directory) can be applied to gcc to
6494 circumvent the problem. A future GCC release will contain a complete
6497 The previous G++ debug info problem (mentioned below for the gdb-4.7
6498 release) is fixed in gcc version 2.3.2.
6500 * Improved configure script
6502 The `configure' script will now attempt to guess your system type if
6503 you don't supply a host system type. The old scheme of supplying a
6504 host system triplet is preferable over using this. All the magic is
6505 done in the new `config.guess' script. Examine it for details.
6507 We have also brought our configure script much more in line with the FSF's
6508 version. It now supports the --with-xxx options. In particular,
6509 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6510 The resulting GDB will not be able to read arbitrary object file formats --
6511 only the format ``expected'' to be used on the configured target system.
6512 We hope to make this the default in a future release.
6514 * Documentation improvements
6516 There's new internal documentation on how to modify GDB, and how to
6517 produce clean changes to the code. We implore people to read it
6518 before submitting changes.
6520 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6521 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6522 `info' files are also provided. To build `info' files from scratch,
6523 you will need the latest `makeinfo' release, which will be available in
6524 a future texinfo-X.Y release.
6526 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6527 We're not sure exactly which versions have this problem, but it has
6528 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6529 or better. If that isn't possible, there is a patch in
6530 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6531 around this problem.
6535 GDB now supports array constants that can be used in expressions typed in by
6536 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6537 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6540 The new directory `gdb/sparclite' contains a program that demonstrates
6541 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6543 * New native hosts supported
6545 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6546 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6548 * New targets supported
6550 AMD 29k family via UDI a29k-amd-udi or udi29k
6552 * New file formats supported
6554 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6555 HPUX core files, and SCO 3.2v2 core files.
6559 Attaching to processes now works again; thanks for the many bug reports.
6561 We have also stomped on a bunch of core dumps caused by
6562 printf_filtered("%s") problems.
6564 We eliminated a copyright problem on the rpc and ptrace header files
6565 for VxWorks, which was discovered at the last minute during the 4.7
6566 release. You should now be able to build a VxWorks GDB.
6568 You can now interrupt gdb while an attached process is running. This
6569 will cause the attached process to stop, and give control back to GDB.
6571 We fixed problems caused by using too many file descriptors
6572 for reading symbols from object files and libraries. This was
6573 especially a problem for programs that used many (~100) shared
6576 The `step' command now only enters a subroutine if there is line number
6577 information for the subroutine. Otherwise it acts like the `next'
6578 command. Previously, `step' would enter subroutines if there was
6579 any debugging information about the routine. This avoids problems
6580 when using `cc -g1' on MIPS machines.
6582 * Internal improvements
6584 GDB's internal interfaces have been improved to make it easier to support
6585 debugging of multiple languages in the future.
6587 GDB now uses a common structure for symbol information internally.
6588 Minimal symbols (derived from linkage symbols in object files), partial
6589 symbols (from a quick scan of debug information), and full symbols
6590 contain a common subset of information, making it easier to write
6591 shared code that handles any of them.
6593 * New command line options
6595 We now accept --silent as an alias for --quiet.
6599 The memory-mapped-malloc library is now licensed under the GNU Library
6600 General Public License.
6602 *** Changes in GDB-4.7:
6604 * Host/native/target split
6606 GDB has had some major internal surgery to untangle the support for
6607 hosts and remote targets. Now, when you configure GDB for a remote
6608 target, it will no longer load in all of the support for debugging
6609 local programs on the host. When fully completed and tested, this will
6610 ensure that arbitrary host/target combinations are possible.
6612 The primary conceptual shift is to separate the non-portable code in
6613 GDB into three categories. Host specific code is required any time GDB
6614 is compiled on that host, regardless of the target. Target specific
6615 code relates to the peculiarities of the target, but can be compiled on
6616 any host. Native specific code is everything else: it can only be
6617 built when the host and target are the same system. Child process
6618 handling and core file support are two common `native' examples.
6620 GDB's use of /proc for controlling Unix child processes is now cleaner.
6621 It has been split out into a single module under the `target_ops' vector,
6622 plus two native-dependent functions for each system that uses /proc.
6624 * New hosts supported
6626 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6627 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6628 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6630 * New targets supported
6632 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6633 68030 and CPU32 m68030-*-*, m68332-*-*
6635 * New native hosts supported
6637 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6638 (386bsd is not well tested yet)
6639 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6641 * New file formats supported
6643 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6644 supports reading of `a.out.adobe' object files, which are an a.out
6645 format extended with minimal information about multiple sections.
6649 `show copying' is the same as the old `info copying'.
6650 `show warranty' is the same as `info warrantee'.
6651 These were renamed for consistency. The old commands continue to work.
6653 `info handle' is a new alias for `info signals'.
6655 You can now define pre-command hooks, which attach arbitrary command
6656 scripts to any command. The commands in the hook will be executed
6657 prior to the user's command. You can also create a hook which will be
6658 executed whenever the program stops. See gdb.texinfo.
6662 We now deal with Cfront style name mangling, and can even extract type
6663 info from mangled symbols. GDB can automatically figure out which
6664 symbol mangling style your C++ compiler uses.
6666 Calling of methods and virtual functions has been improved as well.
6670 The crash that occured when debugging Sun Ansi-C compiled binaries is
6671 fixed. This was due to mishandling of the extra N_SO stabs output
6674 We also finally got Ultrix 4.2 running in house, and fixed core file
6675 support, with help from a dozen people on the net.
6677 John M. Farrell discovered that the reason that single-stepping was so
6678 slow on all of the Mips based platforms (primarily SGI and DEC) was
6679 that we were trying to demangle and lookup a symbol used for internal
6680 purposes on every instruction that was being stepped through. Changing
6681 the name of that symbol so that it couldn't be mistaken for a C++
6682 mangled symbol sped things up a great deal.
6684 Rich Pixley sped up symbol lookups in general by getting much smarter
6685 about when C++ symbol mangling is necessary. This should make symbol
6686 completion (TAB on the command line) much faster. It's not as fast as
6687 we'd like, but it's significantly faster than gdb-4.6.
6691 A new user controllable variable 'call_scratch_address' can
6692 specify the location of a scratch area to be used when GDB
6693 calls a function in the target. This is necessary because the
6694 usual method of putting the scratch area on the stack does not work
6695 in systems that have separate instruction and data spaces.
6697 We integrated changes to support the 29k UDI (Universal Debugger
6698 Interface), but discovered at the last minute that we didn't have all
6699 of the appropriate copyright paperwork. We are working with AMD to
6700 resolve this, and hope to have it available soon.
6704 We have sped up the remote serial line protocol, especially for targets
6705 with lots of registers. It now supports a new `expedited status' ('T')
6706 message which can be used in place of the existing 'S' status message.
6707 This allows the remote stub to send only the registers that GDB
6708 needs to make a quick decision about single-stepping or conditional
6709 breakpoints, eliminating the need to fetch the entire register set for
6710 each instruction being stepped through.
6712 The GDB remote serial protocol now implements a write-through cache for
6713 registers, only re-reading the registers if the target has run.
6715 There is also a new remote serial stub for SPARC processors. You can
6716 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6717 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6718 processor with a serial port.
6722 Configure.in files have become much easier to read and modify. A new
6723 `table driven' format makes it more obvious what configurations are
6724 supported, and what files each one uses.
6728 There is a new opcodes library which will eventually contain all of the
6729 disassembly routines and opcode tables. At present, it only contains
6730 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6731 disassembler (binutils/objdump) to share these routines.
6733 The libiberty library is now copylefted under the GNU Library General
6734 Public License. This allows more liberal use, and was done so libg++
6735 can use it. This makes no difference to GDB, since the Library License
6736 grants all the rights from the General Public License.
6740 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6741 reference to the stabs symbol info used by the debugger. It is (as far
6742 as we know) the only published document on this fascinating topic. We
6743 encourage you to read it, compare it to the stabs information on your
6744 system, and send improvements on the document in general (to
6745 bug-gdb@prep.ai.mit.edu).
6747 And, of course, many bugs have been fixed.
6750 *** Changes in GDB-4.6:
6752 * Better support for C++ function names
6754 GDB now accepts as input the "demangled form" of C++ overloaded function
6755 names and member function names, and can do command completion on such names
6756 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6757 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6758 Make use of command completion, it is your friend.
6760 GDB also now accepts a variety of C++ mangled symbol formats. They are
6761 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6762 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6763 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6764 for the list of formats.
6766 * G++ symbol mangling problem
6768 Recent versions of gcc have a bug in how they emit debugging information for
6769 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6770 directory) can be applied to gcc to fix the problem. Alternatively, if you
6771 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6772 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6773 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6776 * New 'maintenance' command
6778 All of the commands related to hacking GDB internals have been moved out of
6779 the main command set, and now live behind the 'maintenance' command. This
6780 can also be abbreviated as 'mt'. The following changes were made:
6782 dump-me -> maintenance dump-me
6783 info all-breakpoints -> maintenance info breakpoints
6784 printmsyms -> maintenance print msyms
6785 printobjfiles -> maintenance print objfiles
6786 printpsyms -> maintenance print psymbols
6787 printsyms -> maintenance print symbols
6789 The following commands are new:
6791 maintenance demangle Call internal GDB demangler routine to
6792 demangle a C++ link name and prints the result.
6793 maintenance print type Print a type chain for a given symbol
6795 * Change to .gdbinit file processing
6797 We now read the $HOME/.gdbinit file before processing the argv arguments
6798 (e.g. reading symbol files or core files). This allows global parameters to
6799 be set, which will apply during the symbol reading. The ./.gdbinit is still
6800 read after argv processing.
6802 * New hosts supported
6804 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6806 GNU/Linux support i386-unknown-linux or linux
6808 We are also including code to support the HP/PA running BSD and HPUX. This
6809 is almost guaranteed not to work, as we didn't have time to test or build it
6810 for this release. We are including it so that the more adventurous (or
6811 masochistic) of you can play with it. We also had major problems with the
6812 fact that the compiler that we got from HP doesn't support the -g option.
6815 * New targets supported
6817 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6819 * More smarts about finding #include files
6821 GDB now remembers the compilation directory for all include files, and for
6822 all files from which C is generated (like yacc and lex sources). This
6823 greatly improves GDB's ability to find yacc/lex sources, and include files,
6824 especially if you are debugging your program from a directory different from
6825 the one that contains your sources.
6827 We also fixed a bug which caused difficulty with listing and setting
6828 breakpoints in include files which contain C code. (In the past, you had to
6829 try twice in order to list an include file that you hadn't looked at before.)
6831 * Interesting infernals change
6833 GDB now deals with arbitrary numbers of sections, where the symbols for each
6834 section must be relocated relative to that section's landing place in the
6835 target's address space. This work was needed to support ELF with embedded
6836 stabs used by Solaris-2.0.
6838 * Bug fixes (of course!)
6840 There have been loads of fixes for the following things:
6841 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6842 i960, stabs, DOS(GO32), procfs, etc...
6844 See the ChangeLog for details.
6846 *** Changes in GDB-4.5:
6848 * New machines supported (host and target)
6850 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6852 SGI Irix-4.x mips-sgi-irix4 or iris4
6854 * New malloc package
6856 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6857 Mmalloc is capable of handling mutiple heaps of memory. It is also
6858 capable of saving a heap to a file, and then mapping it back in later.
6859 This can be used to greatly speedup the startup of GDB by using a
6860 pre-parsed symbol table which lives in a mmalloc managed heap. For
6861 more details, please read mmalloc/mmalloc.texi.
6865 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6866 'help info proc' for details.
6868 * MIPS ecoff symbol table format
6870 The code that reads MIPS symbol table format is now supported on all hosts.
6871 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6874 * File name changes for MS-DOS
6876 Many files in the config directories have been renamed to make it easier to
6877 support GDB on MS-DOSe systems (which have very restrictive file name
6878 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6879 environment) is close to working but has some remaining problems. Note
6880 that debugging of DOS programs is not supported, due to limitations
6881 in the ``operating system'', but it can be used to host cross-debugging.
6883 * Cross byte order fixes
6885 Many fixes have been made to support cross debugging of Sparc and MIPS
6886 targets from hosts whose byte order differs.
6888 * New -mapped and -readnow options
6890 If memory-mapped files are available on your system through the 'mmap'
6891 system call, you can use the -mapped option on the `file' or
6892 `symbol-file' commands to cause GDB to write the symbols from your
6893 program into a reusable file. If the program you are debugging is
6894 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6895 Future GDB debugging sessions will notice the presence of this file,
6896 and will quickly map in symbol information from it, rather than reading
6897 the symbol table from the executable program. Using the '-mapped'
6898 option in a GDB `file' or `symbol-file' command has the same effect as
6899 starting GDB with the '-mapped' command-line option.
6901 You can cause GDB to read the entire symbol table immediately by using
6902 the '-readnow' option with any of the commands that load symbol table
6903 information (or on the GDB command line). This makes the command
6904 slower, but makes future operations faster.
6906 The -mapped and -readnow options are typically combined in order to
6907 build a `fred.syms' file that contains complete symbol information.
6908 A simple GDB invocation to do nothing but build a `.syms' file for future
6911 gdb -batch -nx -mapped -readnow programname
6913 The `.syms' file is specific to the host machine on which GDB is run.
6914 It holds an exact image of GDB's internal symbol table. It cannot be
6915 shared across multiple host platforms.
6917 * longjmp() handling
6919 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6920 siglongjmp() without losing control. This feature has not yet been ported to
6921 all systems. It currently works on many 386 platforms, all MIPS-based
6922 platforms (SGI, DECstation, etc), and Sun3/4.
6926 Preliminary work has been put in to support the new Solaris OS from Sun. At
6927 this time, it can control and debug processes, but it is not capable of
6932 As always, many many bug fixes. The major areas were with g++, and mipsread.
6933 People using the MIPS-based platforms should experience fewer mysterious
6934 crashes and trashed symbol tables.
6936 *** Changes in GDB-4.4:
6938 * New machines supported (host and target)
6940 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6942 BSD Reno on Vax vax-dec-bsd
6943 Ultrix on Vax vax-dec-ultrix
6945 * New machines supported (target)
6947 AMD 29000 embedded, using EBMON a29k-none-none
6951 GDB continues to improve its handling of C++. `References' work better.
6952 The demangler has also been improved, and now deals with symbols mangled as
6953 per the Annotated C++ Reference Guide.
6955 GDB also now handles `stabs' symbol information embedded in MIPS
6956 `ecoff' symbol tables. Since the ecoff format was not easily
6957 extensible to handle new languages such as C++, this appeared to be a
6958 good way to put C++ debugging info into MIPS binaries. This option
6959 will be supported in the GNU C compiler, version 2, when it is
6962 * New features for SVR4
6964 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6965 shared libraries. Debugging dynamically linked programs should present
6966 only minor differences from debugging statically linked programs.
6968 The `info proc' command will print out information about any process
6969 on an SVR4 system (including the one you are debugging). At the moment,
6970 it prints the address mappings of the process.
6972 If you bring up GDB on another SVR4 system, please send mail to
6973 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6975 * Better dynamic linking support in SunOS
6977 Reading symbols from shared libraries which contain debugging symbols
6978 now works properly. However, there remain issues such as automatic
6979 skipping of `transfer vector' code during function calls, which
6980 make it harder to debug code in a shared library, than to debug the
6981 same code linked statically.
6985 GDB is now using the latest `getopt' routines from the FSF. This
6986 version accepts the -- prefix for options with long names. GDB will
6987 continue to accept the old forms (-option and +option) as well.
6988 Various single letter abbreviations for options have been explicity
6989 added to the option table so that they won't get overshadowed in the
6990 future by other options that begin with the same letter.
6994 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6995 Many assorted bugs have been handled. Many more remain to be handled.
6996 See the various ChangeLog files (primarily in gdb and bfd) for details.
6999 *** Changes in GDB-4.3:
7001 * New machines supported (host and target)
7003 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7004 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7005 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7007 * Almost SCO Unix support
7009 We had hoped to support:
7010 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7011 (except for core file support), but we discovered very late in the release
7012 that it has problems with process groups that render gdb unusable. Sorry
7013 about that. I encourage people to fix it and post the fixes.
7015 * Preliminary ELF and DWARF support
7017 GDB can read ELF object files on System V Release 4, and can handle
7018 debugging records for C, in DWARF format, in ELF files. This support
7019 is preliminary. If you bring up GDB on another SVR4 system, please
7020 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7025 GDB now uses the latest `readline' library. One user-visible change
7026 is that two tabs will list possible command completions, which previously
7027 required typing M-? (meta-question mark, or ESC ?).
7031 The `stepi' bug that many of you noticed has been squashed.
7032 Many bugs in C++ have been handled. Many more remain to be handled.
7033 See the various ChangeLog files (primarily in gdb and bfd) for details.
7035 * State of the MIPS world (in case you wondered):
7037 GDB can understand the symbol tables emitted by the compilers
7038 supplied by most vendors of MIPS-based machines, including DEC. These
7039 symbol tables are in a format that essentially nobody else uses.
7041 Some versions of gcc come with an assembler post-processor called
7042 mips-tfile. This program is required if you want to do source-level
7043 debugging of gcc-compiled programs. I believe FSF does not ship
7044 mips-tfile with gcc version 1, but it will eventually come with gcc
7047 Debugging of g++ output remains a problem. g++ version 1.xx does not
7048 really support it at all. (If you're lucky, you should be able to get
7049 line numbers and stack traces to work, but no parameters or local
7050 variables.) With some work it should be possible to improve the
7053 When gcc version 2 is released, you will have somewhat better luck.
7054 However, even then you will get confusing results for inheritance and
7057 We will eventually provide full debugging of g++ output on
7058 DECstations. This will probably involve some kind of stabs-in-ecoff
7059 encapulation, but the details have not been worked out yet.
7062 *** Changes in GDB-4.2:
7064 * Improved configuration
7066 Only one copy of `configure' exists now, and it is not self-modifying.
7067 Porting BFD is simpler.
7071 The `step' and `next' commands now only stop at the first instruction
7072 of a source line. This prevents the multiple stops that used to occur
7073 in switch statements, for-loops, etc. `Step' continues to stop if a
7074 function that has debugging information is called within the line.
7078 Lots of small bugs fixed. More remain.
7080 * New host supported (not target)
7082 Intel 386 PC clone running Mach i386-none-mach
7085 *** Changes in GDB-4.1:
7087 * Multiple source language support
7089 GDB now has internal scaffolding to handle several source languages.
7090 It determines the type of each source file from its filename extension,
7091 and will switch expression parsing and number formatting to match the
7092 language of the function in the currently selected stack frame.
7093 You can also specifically set the language to be used, with
7094 `set language c' or `set language modula-2'.
7098 GDB now has preliminary support for the GNU Modula-2 compiler,
7099 currently under development at the State University of New York at
7100 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7101 continue through the fall of 1991 and into 1992.
7103 Other Modula-2 compilers are currently not supported, and attempting to
7104 debug programs compiled with them will likely result in an error as the
7105 symbol table is read. Feel free to work on it, though!
7107 There are hooks in GDB for strict type checking and range checking,
7108 in the `Modula-2 philosophy', but they do not currently work.
7112 GDB can now write to executable and core files (e.g. patch
7113 a variable's value). You must turn this switch on, specify
7114 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7115 by assigning a new value to a variable. Modifications take
7118 * Automatic SunOS shared library reading
7120 When you run your program, GDB automatically determines where its
7121 shared libraries (if any) have been loaded, and reads their symbols.
7122 The `share' command is no longer needed. This also works when
7123 examining core files.
7127 You can specify the number of lines that the `list' command shows.
7130 * New machines supported (host and target)
7132 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7133 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7134 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7136 * New hosts supported (not targets)
7138 IBM RT/PC: romp-ibm-aix or rtpc
7140 * New targets supported (not hosts)
7142 AMD 29000 embedded with COFF a29k-none-coff
7143 AMD 29000 embedded with a.out a29k-none-aout
7144 Ultracomputer remote kernel debug a29k-nyu-kern
7146 * New remote interfaces
7152 *** Changes in GDB-4.0:
7156 Wide output is wrapped at good places to make the output more readable.
7158 Gdb now supports cross-debugging from a host machine of one type to a
7159 target machine of another type. Communication with the target system
7160 is over serial lines. The ``target'' command handles connecting to the
7161 remote system; the ``load'' command will download a program into the
7162 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7163 also supports debugging of realtime processes running under VxWorks,
7164 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7165 stub on the target system.
7167 New CPUs supported include the AMD 29000 and Intel 960.
7169 GDB now reads object files and symbol tables via a ``binary file''
7170 library, which allows a single copy of GDB to debug programs of multiple
7171 object file types such as a.out and coff.
7173 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7174 refcard.dvi and refcard.ps are available to format it).
7177 * Control-Variable user interface simplified
7179 All variables that control the operation of the debugger can be set
7180 by the ``set'' command, and displayed by the ``show'' command.
7182 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7183 ``Show prompt'' produces the response:
7184 Gdb's prompt is new-gdb=>.
7186 What follows are the NEW set commands. The command ``help set'' will
7187 print a complete list of old and new set commands. ``help set FOO''
7188 will give a longer description of the variable FOO. ``show'' will show
7189 all of the variable descriptions and their current settings.
7191 confirm on/off: Enables warning questions for operations that are
7192 hard to recover from, e.g. rerunning the program while
7193 it is already running. Default is ON.
7195 editing on/off: Enables EMACS style command line editing
7196 of input. Previous lines can be recalled with
7197 control-P, the current line can be edited with control-B,
7198 you can search for commands with control-R, etc.
7201 history filename NAME: NAME is where the gdb command history
7202 will be stored. The default is .gdb_history,
7203 or the value of the environment variable
7206 history size N: The size, in commands, of the command history. The
7207 default is 256, or the value of the environment variable
7210 history save on/off: If this value is set to ON, the history file will
7211 be saved after exiting gdb. If set to OFF, the
7212 file will not be saved. The default is OFF.
7214 history expansion on/off: If this value is set to ON, then csh-like
7215 history expansion will be performed on
7216 command line input. The default is OFF.
7218 radix N: Sets the default radix for input and output. It can be set
7219 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7220 in the current radix, so "set radix 10" is always a no-op.
7222 height N: This integer value is the number of lines on a page. Default
7223 is 24, the current `stty rows'' setting, or the ``li#''
7224 setting from the termcap entry matching the environment
7227 width N: This integer value is the number of characters on a line.
7228 Default is 80, the current `stty cols'' setting, or the ``co#''
7229 setting from the termcap entry matching the environment
7232 Note: ``set screensize'' is obsolete. Use ``set height'' and
7233 ``set width'' instead.
7235 print address on/off: Print memory addresses in various command displays,
7236 such as stack traces and structure values. Gdb looks
7237 more ``symbolic'' if you turn this off; it looks more
7238 ``machine level'' with it on. Default is ON.
7240 print array on/off: Prettyprint arrays. New convenient format! Default
7243 print demangle on/off: Print C++ symbols in "source" form if on,
7246 print asm-demangle on/off: Same, for assembler level printouts
7249 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7252 * Support for Epoch Environment.
7254 The epoch environment is a version of Emacs v18 with windowing. One
7255 new command, ``inspect'', is identical to ``print'', except that if you
7256 are running in the epoch environment, the value is printed in its own
7260 * Support for Shared Libraries
7262 GDB can now debug programs and core files that use SunOS shared libraries.
7263 Symbols from a shared library cannot be referenced
7264 before the shared library has been linked with the program (this
7265 happens after you type ``run'' and before the function main() is entered).
7266 At any time after this linking (including when examining core files
7267 from dynamically linked programs), gdb reads the symbols from each
7268 shared library when you type the ``sharedlibrary'' command.
7269 It can be abbreviated ``share''.
7271 sharedlibrary REGEXP: Load shared object library symbols for files
7272 matching a unix regular expression. No argument
7273 indicates to load symbols for all shared libraries.
7275 info sharedlibrary: Status of loaded shared libraries.
7280 A watchpoint stops execution of a program whenever the value of an
7281 expression changes. Checking for this slows down execution
7282 tremendously whenever you are in the scope of the expression, but is
7283 quite useful for catching tough ``bit-spreader'' or pointer misuse
7284 problems. Some machines such as the 386 have hardware for doing this
7285 more quickly, and future versions of gdb will use this hardware.
7287 watch EXP: Set a watchpoint (breakpoint) for an expression.
7289 info watchpoints: Information about your watchpoints.
7291 delete N: Deletes watchpoint number N (same as breakpoints).
7292 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7293 enable N: Re-enables watchpoint number N (same as breakpoints).
7296 * C++ multiple inheritance
7298 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7301 * C++ exception handling
7303 Gdb now supports limited C++ exception handling. Besides the existing
7304 ability to breakpoint on an exception handler, gdb can breakpoint on
7305 the raising of an exception (before the stack is peeled back to the
7308 catch FOO: If there is a FOO exception handler in the dynamic scope,
7309 set a breakpoint to catch exceptions which may be raised there.
7310 Multiple exceptions (``catch foo bar baz'') may be caught.
7312 info catch: Lists all exceptions which may be caught in the
7313 current stack frame.
7316 * Minor command changes
7318 The command ``call func (arg, arg, ...)'' now acts like the print
7319 command, except it does not print or save a value if the function's result
7320 is void. This is similar to dbx usage.
7322 The ``up'' and ``down'' commands now always print the frame they end up
7323 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7324 frames without printing.
7326 * New directory command
7328 'dir' now adds directories to the FRONT of the source search path.
7329 The path starts off empty. Source files that contain debug information
7330 about the directory in which they were compiled can be found even
7331 with an empty path; Sun CC and GCC include this information. If GDB can't
7332 find your source file in the current directory, type "dir .".
7334 * Configuring GDB for compilation
7336 For normal use, type ``./configure host''. See README or gdb.texinfo
7339 GDB now handles cross debugging. If you are remotely debugging between
7340 two different machines, type ``./configure host -target=targ''.
7341 Host is the machine where GDB will run; targ is the machine
7342 where the program that you are debugging will run.